UMSS22 Biomedical Sciences
UMSS22 Presentations by Category
UMSS22 Physical and Mathematical Sciences
UMSS22 Engineering and Information Sciences
UMSS22 Interdisciplinary Sciences
UMSS22 Business, Education, and Art
Biomedical Sciences
1001. Role of Heme Oxygenase in Endurance Neuromuscular Electrical Stimulation Mediated Improvement of Dystrophic Skeletal Muscle
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Amanda Ignacz, Elisabeth Kilroy, Kodey Silknitter, Clarissa Henry
Graduate Student Presentation
Faculty Mentor: Clarissa Henry
Abstract: Duchenne muscular dystrophy (DMD) is a fatal, progressive muscle-wasting disease that affects 1 in 5000 live male births. DMD is caused by mutations, usually deletions, in the gene coding for dystrophin production. Dystrophin acts as a link between the actin cytoskeleton and the extracellular matrix in myocytes. With a lack of functional dystrophin, as observed in DMD patients, muscle becomes more susceptible to damage as the cells contract and relax resulting in muscle degeneration and weakness. In a zebrafish model for this disease (sapje) it has been shown that the dystrophic phenotype can be ameliorated through endurance neuromuscular electrical stimulation (eNMES), providing insight on the effect of exercise on muscle structure and function. However, the molecular mechanisms of eNMES-mediated improvement in dmd mutants is not well-understood. Heme oxygenase (HO), an antioxidant that has been implicated as a potential therapeutic treatment in both zebrafish and mouse models of dmd, was found to be upregulated with eNMES treatment in both wild-type and dmd embryos in an RNA Sequencing (RNA Seq) study. A knockdown of hmox1a expression in dmd mutants showed no skeletal muscle improvement after eNMES treatment. This suggests that HO is necessary for eNMES-mediated improvement, and a combination of HO treatments and endurance activity could be a potential therapeutic approach to robust improvement of dystrophic muscle in DMD.
1002. Mouse Models of NADK2 Deficiency Analyzed for Metabolic and Gene Expression Changes to Elucidate Pathophysiology
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): George Murray, Robert Burgess
Graduate Student Presentation
Faculty Mentor: Robert Burgess
Abstract: NADK2 encodes the mitochondrial NAD Kinase, which phosphorylates nicotinamide adenine dinucleotide (NAD) to form NADP, an important cofactor involved in a wide variety of metabolic pathways. In patients, rare recessive mutations in NADK2 are associated with a syndromic neurological mitochondrial disease with metabolic problems, hyperlysinemia, neuropathy, and neurodegeneration. Here we describe a chemically induced mouse mutation in Nadk2, S330P, which causes severe neuromuscular disease and shortened lifespan. We observe denervation of neuromuscular junctions by 5 weeks of age and pronounced muscle atrophy by 11 weeks. These mutants also display progressive degeneration of cerebellar Purkinje cells, a histopathological feature of NADK2 deficiency in patients. Metabolomic profiling indicates elevated lysine in brain, liver, muscle, and spinal cord with disruption of NADP-dependent biological pathways. Combined metabolomics and transcriptomics identifies disruption of glycolysis and gluconeogenesis with changes in the abundance of intermediate glycolytic analytes and gene set enrichment analysis indicates deficits in beta-oxidation of fatty acids. These mice broadly recapitulate the pathophysiological features of disease in patients and will be useful for the study of NADK2 deficiency.
1003. Continuous, Non-Destructive Detection of Surface Bacterial Growth with Bioinspired Vascularized Polymers
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Brandon Dixon, Anna Briley, Caitlin Howell
Graduate Student Presentation
Faculty Mentor: Caitlin Howell
Abstract: Reducing or eliminating bacteria on surfaces is a vital part of ensuring food safety, drinking water quality, and preventing infection. However, nearly all current methods of bacterial detection are destructive and single-use. In this work, we present a new method to detect bacteria at surfaces that is continuous, non-destructive, and reusable. Inspired by vascular systems in nature that permit chemical communication between the surface and underlying tissues of an organism, metabolites diffusing from surface bacteria were detected in channels filled with a carrier fluid embedded in a polymer matrix. The carrier fluid was analyzed using conductivity, ultraviolet-visible (UV-vis) spectroscopy, and high-performance liquid chromatography; methods that ranged in sensitivity and cost. Using Escherichia coli K12 as a model surface bacterial system, carrier fluid from samples compared to controls with no bacteria exhibited an average increase of 1.27 mS/cm in conductivity, an increase of 0.017 absorbance units at 600nm in UV-vis spectroscopy, and the significant differences in two major peaks in HPLC detected at 254nm. Creating a multilayer polymer optimized the network and allowed the system to be more easily re-used, as the channels could be evacuated and refilled multiple times with carrier fluid for the continuous detection of surface bacteria with similar results to previous single-use experiments. Additionally, bacteria growth could be determined after 8 hours since the application of bacteria to the surface pending channel resonance time and bacteria growth phase. This work lays the foundation for the use of vascularized polymers as an adaptive system for the continuous, non-destructive detection of surface bacteria with multiple methods for analysis.
1004. Characterization of the Human Cardiac Progenitor Cell Secretome – Presentation withdrawn from judging
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Michayla Moore, Calvin Vary
Graduate Student Presentation
Faculty Mentor: Calvin Vary
Abstract: Heart Disease (HD) remains the greatest cause of death worldwide. Preclinical evidence has highlighted the potential role of Cardiac Progenitor Cells (CPCs) in regulation of cardiac repair after injury, with an emerging role of CPC secreted proteins in this process. We have been studying CPCs isolated from human left ventricular myocardium characterized by their high proliferative capacity in vitro. These cells (human highly proliferative cells, hHiPCs) are characterized by high expression of CD105/Endoglin. With this knowledge, we hypothesized that hHiPCs associated with improvement in cardiac remodeling after MI will have a secretome characterized by higher expression of pro-angiogenic and pro-proliferative proteins, and these are regulated by the BMP/CD105 pathway. An unbiased proteomics approach (LC-MS/MS) was used in our lab to identify proteins secreted from hHiPCs pre-treated with the CD105 ligand BMP9 (5 ng/mL) compared to non-treated controls. Several pro-angiogenic secreted proteins were identified in clone 11 including CCN2, CXCL6, and TGFB2. We found a significant increase in the secretion of Sclerostin (SOST) in BMP9 treated hHiPC compared to non-treated controls. These data were also confirmed by ELISA and RT-qPCR. Similarly, using LC-MS/MS we found a significant increase in CD105 expression in the membrane fraction of clone 11 compared to clone 22 indicating its potential role in positive heart remodeling effects. The increase in pro-angiogenic factors after BMP9 treatment may suggest the potential relevance of BMP9 treatment in cardiac progenitor cell secretome mediated repair and will be investigated in the future.
1005. Mybl2 is a Developmental Control Gene that Regulates Asymmetry and Dynamic Expression of Genes in the Cochlea
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Caryl Young, Matthew Thompson, Vidhya Munnamalai
Graduate Student Presentation
Faculty Mentor: Vidhya Munnamalai
Abstract: The cochlea is an asymmetrically patterned organ that is determined by the interaction of several signaling pathways during the early stages of development. The sensory epithelium has one row of sound-detecting inner hair cells (IHCs) and three rows of sound-amplifying outer hair cells (OHCs). Here, we define a novel role for MYBL2 in establishing radial asymmetry by regulating Jag1, an important prosensory regulator in the medial compartment and Shroom1 in the lateral compartment. We hypothesize an incoherent feed-forward loop exists in which, Jag1 and Mybl2 are Wnt target genes and MYBL2 feeds-forward to repress Jag1 leading to Jag1 refinement. We also hypothesize that the Wnt-MYBL2 pathway negatively regulates Shroom1, a laterally expressed Bmp candidate target gene. We tested these hypotheses in β-catenin and Mybl2 conditional knockouts (cKOs) on E14.5. Analysis of Wnt pathway mutants show that Jag1, Mybl2 and Shroom1 are regulated by the Wnt pathway. Mybl2 cKOs show an expansion of the JAG1 domain and its downstream effector, SOX2 that labels the sensory domain, and an increase of Shroom1 on E14.5. These data suggest that MYBL2 represses Jag1 and Shroom1. On E18.5, Mybl2 cKO cochleas showed extra IHCs and an increase in innervation of the MS domain, which we predict is caused by increased JAG1, and disrupted morphology of cells in the lateral sensory domain, which we predict is caused by increased Shroom1. In conclusion, Mybl2 is a novel developmental control gene that plays a transient, but critical role in establishing sensory boundaries and radial asymmetry in the cochlea.
1006. Low-Dose Arsenic Exposure Alters the Expression of Genes Associated with Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Exposure in Zebrafish Embryos
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Marissa Paine, Meaghan Caron, Emma Boudreaux, Brendan Moline, Keith Hutchison, Benjamin King
Undergraduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS), or “forever chemicals” in the Maine water system have become a critical problem in the state. These hazardous toxins are prevalent in our food, water, and natural resources–causing significant environmental and health concerns. Using the Comparative Toxicogenomics Database (CTD), we found that there are 5,941 and 4,903 genes that respond to PFAS and arsenic, respectively, with 1,547 genes in common. Arsenic is a known carcinogen, with chronic exposure to this chemical resulting in neuropathy, cirrhosis, and anemia. The current standard for arsenic in Maine drinking water is 10 ppb. Exposure to 2 and 10 ppb arsenic has been shown to reduce the innate immune function to the opportunistic pathogen, Pseudomonas aeruginosa, in a zebrafish model. We reanalyzed gene expression data from an RNA sequencing study of zebrafish embryos exposed to 0, 2, and 10 ppb arsenic which were then infected with P. aeruginosa. We found 68 genes were differentially expressed with 10 ppb arsenic exposure and with P. aeruginosa infection. Of these 68 genes, 17 genes had interactions with PFAS in CTD. Of these genes, six were a part of the steroid hormone biosynthesis pathway. This pathway has been identified as a target for endocrine-disrupting chemicals, suggesting that PFAS chemicals may negatively impact growth and development. One of the six genes, leukocyte cell derived chemotaxin 2, was downregulated with arsenic exposure and has important functions in innate immunity. This work is significant in addressing PFAS contamination and potential health effects from exposure.
1007. The Mysterious Gordonia Phage Widow – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Wyatt Oglesby, Ben Curtis, Griffin Lawrence, Jaylee Rice, Emelia Tremblay, Bayarjavkhlan Ganbaatar, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Antibiotic resistance in bacteria is expected to reach epidemic proportions by 2050. To combat this, bacteriophages, viruses that infect bacteria, are being studied as an alternative solution to antibiotics. With more knowledge of phages and their genes, otherwise incurable bacterial diseases may become curable. To increase knowledge about phages and their applications to medicine, novel Gordonia terrae phage, Widow, was isolated and annotated. Widow was isolated in Mattapoisett, MA using an enriched isolation process. It is a lytic cluster CD phage belonging to the Siphoviridae family, containing 63 genes, 43656 total base pairs, and GC content of 67.6%. The placement of the lysin B protein relative to the rest of the lysis cassette may be indicative of the work of a mobile gene element. This is a distinct feature of Widow as this does not follow the canonical genome structure. Further research may be conducted to explore how these phage may be applied in fields such as waste management and bacterial infections, as other G. terrae phage have been utilized in the past. Such research could also provide insight on how phages are able to hijack the bacterial host and cause lysis.
1008. Creating Efficient Anti-Bacterial Surfaces on Catheters with Antibiotic-Free Liquid Coatings
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Chun Ki Fong, Marissa Andersen, Caitlin Howell
Graduate Student Presentation
Faculty Mentor: Caitlin Howell
Abstract: The use of antibiotics to treat infections is widely recognized as a risky long-term strategy, particularly for widespread complications such as catheter-associated urinary tract infections where the potential for the development of resistance is high. In this work, we use bio-inspired liquid coatings to create catheter surfaces that are protein-resistant and antibacterial without the use of antibiotics and use this as a tool to better understand the relationship between protein adhesion and bacterial adhesion on medically relevant surfaces. Through controlling different parameters in the fabrication of liquid coating, it was possible to control the level of whey protein adhesion to a catheter surface. Protein deposition levels were found to be achievable between 0 and 100% with an accuracy of approximately ±10% compared to uncoated controls. Test on bacterial adhesion mimicked the results of the protein deposition studies, with lower levels of bacterial adhesion on catheters with higher levels of protein resistance. The results demonstrate that liquid coatings can be a useful tool in untangling complex interactions in the colonization of abiotic surfaces by living organisms, and can be applied to the production of antibacterial catheters that do not rely on antibiotics.
1009. Triacsin C Inhibition of Acyl-CoA Synthetases Hinders Multiple Myeloma Cell Proliferation and Survival
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Connor Murphy, Heather Fairfield, Mariah Farrell, Victoria DeMambro, Calvin Vary, Michaela Reagan
Graduate Student Presentation
Faculty Mentor: Michaela Reagan
Abstract: Multiple myeloma (MM) is a disease of clonal expansion of malignant plasma cells and has a 5-year survival rate of 50%. Intriguingly, obesity correlates with increased incidence of MM and a poor treatment response, but how dysfunctional fatty acid (FA) metabolism contributes to MM is unknown. Therefore, there is a critical need to understand how FA metabolism contributes to support MM. Changes in FA metabolism have been shown to support cell proliferation, migration and drug resistance in other blood cancers and solid tumors. Thus, we hypothesized that FA metabolism is important to supporting MM proliferation or survival. We used the Cancer Dependency Map, a database of gene fitness in human cancer cell lines to identify that most of the long-chain acyl-CoA synthetase (ACSL) family members supported MM cell line fitness. Therefore, we hypothesized that the ACSL family supports MM cell survival or proliferation. To test this hypothesis, we treated human cell lines with an inhibitor (Triacsin C, TriC) of four of the five human ACSLs (ACSL1, 3, 4 and 5). TriC decreased MM cell proliferation, increased apoptosis, increased the sub-G1 MM cell population, and decreased mitochondrial membrane potential in a dose-dependent manner. MM cells treated with TriC for 24 hours had significantly decreased basal, maximal and ATP-dependent respiration and spare capacity. Taken together, our data suggest that ACSLs support MM cell proliferation, survival, respiration and mitochondrial function. Future studies will use genetic methods to identify specific roles for ACSL members in MM disease progression.
1010. Deletion of Mycobacterial Flotillin Gene to Assess Changes in Virulence of Mycobacterium chelonae
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s):Claire Bourett, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Non-tuberculosis mycobacteria are increasingly causing severe, opportunistic infections, especially in cystic fibrosis and other immunocompromised patients. Mycobacterium abscessus, one of the most drug-resistant species with only a 46% successful treatment rate, is commonly identified as the causative agent. Studying the mechanisms of multidrug resistance within mycobacteria will reveal new targets for potential treatments. The Molloy Lab recently showed that the presence of two prophages, integrated viral genomes, increases antibiotic resistance and the expression of an important antibiotic resistance transcriptional regulator in M. chelonae, a pathogenic mycobacteria closely related to M. abscessus. This strain also demonstrated a ~100-fold increase in expression of a bacterial flotillin gene relative to strains carrying only one or no prophage. To determine if the flotillin gene plays a role in the increased antibiotic resistance we proposed to delete the M. chelonae flotillin gene and compare antibiotic resistance and expression of resistance genes to wildtype strains. 1200-bp sequences that flank the flotillin gene were successfully cloned into a mycobacterial suicide vector, pKO. The vector will be used to delete the flotillin gene in the M. chelonae genome, through homologous recombination. To assess changes in antibiotic resistance, minimum inhibitory concentration assays (MICs) with amikacin will be performed on the deletion strain and compared to the wildtype strain. The effect of the flotillin deletion on expression of antibiotic resistance genes will be determined by qRT-PCR. If flotillin plays a role in the observed antibiotic resistance, flotillin inhibitors could be an attractive drug therapy for drug-resistant mycobacterial infections.
1011. Designing a Functional Trunnion Prototype for Attachment of an Artificial Leg to a Femoral Implant to Be Used for Osseointegrated Prosthetics
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Emma Sperry, David Neivandt
Undergraduate Student Presentation
Faculty Mentor: David Neivandt
Abstract: High infection rates are a significant issue with regard to recovery after orthopedic surgeries involving transcutaneous implants. As a solution, highly porous metal implants have been tested and proven to promote bone and soft tissue ingrowth, including all tissues from the skin down to the bone, thereby creating a biological seal preventing infections arising from external entities. Among the many challenges limb amputees face are irritation and ingrown hairs arising from the fitment of a prosthetic with a socket mounted over the residual stump. The highly porous transcutaneous technology potentially offers a solution to this problem via providing a permanent mounting point that bridges the skin and soft tissues while being anchored in the bone. In order for osseointegrated implants to be a valid surgical treatment for prosthetic users, a functional mounting and pivoting device for attachment of an implant to a prosthetic device that includes a fail-safe mechanism must first be engineered. The present work employs finite element analysis (via SolidWorks) to model the forces required to shear bolts that would connect the prosthetic to an osseointegrated trunnion. Various materials and designs of the bolt are being modeled, including notches of various shapes intended to act as stress risers. Analyzing the modeled stress results at the notch in comparison with known torque and bending moment failure points, as well as average peak forces and moments during daily activities, is providing information necessary to optimize the design to enable daily activities but promote failure under conditions that would potentially lead to danger to the user.
1012. Microfluidic Chanel Applications to Improve a Pulsed-Electric Field Water Purification System
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Amelia Cobb, Liza White, Caitlin Howell
Undergraduate Student Presentation
Faculty Mentor: Caitlin Howell
Abstract: Clean water accessibility is one of the most pressing issues in our modern society as it affects people worldwide and has devastating consequences if unavailable. Researchers at the Wyss Institute at Harvard University developed a pulsed electric field water purification system; however the device’s power consumption is too high for its intended use as a portable system. The purpose of this research is to optimize the water purification system by reducing fabrication costs and overall power consumption. To do this, we have created a flow cell made of metal-coated polyethylene terephthalate (PET) which is spaced with heat activated adhesive and PET. We tested each individual flow cell by attaching the cell to a high voltage DC power supply. We used an oscilloscope to ensure the flow cells produced a square wave, demonstrating that electricity effectively flows through the system, and we used a digital voltmeter to ensure continuity throughout the metal coating. These results demonstrate that metal-coated PET can effectively conduct electricity which is needed for a pulse electric field water purification system. Acknowledgements: The authors thank SAPPI North America, the Wyss Institute at Harvard University, Elizabeth Calamari, Richard Novek, Don Ingber, and Emma Perry. This work was supported by the National Science Foundation, Award No. 2032482
1013. Synthesis and Decarboxylation of Eumelanoids
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Alexander Wilkins, Matthew Brichacek
Undergraduate Student Presentation
Faculty Mentor: Matthew Brichacek
Abstract: Parkinson’s disease is a neurodegenerative disorder that affects dopamine-producing nerve cells in the brain. Patients with Parkinson’s commonly have a lack of a pigment called neuromelanin, which a healthy individual would have an abundance of. Neuromelanin is found in portions of the brain, and is a mixed melanin composed of eumelanin and pheomelanin polymers. Synthetic neuromelanin analogs can be used to better understand this neurodegenerative disorder since obtaining the natural polymer is challenging. In this study, the syntheses of brominated eumelanoid-methyl esters were conducted. The halogen-free eumelanoid was synthesized and decarboxylated in 10% yield. The 4-bromo eumelanoid decarboxylation was attempted with copper powder, copper (II) chromite, and a copper salt catalyst. Future endeavors will identify alternative decarboxylation methods as well as use a Miyuara borylation and a Suzuki coupling to synthesize the neuromelanin product. The photophysical and biological properties of the new molecules will be assessed.
1014. AAV9-Ighmbp2 Gene Therapy Significantly Improves Motor Performance in Severe SMARD1-like Mouse Model, nmdem3, and CMT2S Mouse Model, nmdem5
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Sarah Holbrook, Amy Hicks, Paige Martin, Greg Cox
Graduate Student Presentation
Faculty Mentor: Greg Cox
Abstract: Autosomal recessive mutations in IGHMBP2, a ubiquitously expressed DNA/RNA helicase, have been linked to childhood neuromuscular degenerative diseases (NMDs). C57BL/6J-Ighmbp2em3Cx is a SMARD1-like strain, or Spinal Muscular Atrophy with Respiratory Distress, created via CRISPR-Cas9 targeting of the IGHMBP2 gene and hereafter referred to as em3. SMARD1 is characterized by muscle weakness starting in the distal extremities and diaphragmatic paralysis leading to respiratory failure. Most patients are diagnosed in early infancy and die in early childhood. The em3 mouse has more severe muscle atrophy than the historical SMARD1-like model (nmd2J) in the hind limb, diaphragm, and intercostal muscles. The em3 mouse model also has an average lifespan of ~3 weeks compared to the 2J’s ~3 month lifespan. C57BL/6J-Ighmbp2em5Cx is a Charcot-Marie-Tooth disease type 2S model that does not impact lifespan but does impact motor and sensory function beginning around the 4 week timepoint. Gene therapy has shown promise in another NMD, Spinal Muscular Atrophy (SMA). In collaboration with the Meyer lab at Nationwide Children’s Hospital in Columbus, OH, we are testing 2 different AAV9-Ighmbp2 vectors. Each has a different promoter expressing varying levels of IGHMBP2. We performed postnatal day 1 intracerebroventricular injections on em3 and em5 mutants to determine the efficacy of each treatment. Using a variety of assays to determine strength and neuromuscular degeneration, we determined that the P546 promoter is more effective in EM3 mutant mice and that either virus shows equal improvement the EM5 mutant mice.
1015. Cohabitating Prophage Interactions and their Role in Regulation of Important Mycobacterial Antibiotic Resistance Genes
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Matthew Cox, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacterium abscessus causes pulmonary and soft tissue infection in cystic fibrosis patients, and is oftentimes multidrug resistant. Understanding the mechanisms of multidrug resistance is critical for developing alternative treatments. Prophage, viral genomes integrated into the host genome, increase antibiotic resistance in mycobacteria but the mechanism is not understood. Our lab demonstrated that pathogenic mycobacteria carrying two prophages, McProf and BPs, has increased antibiotic resistance and expression of antibiotic resistance gene whiB7 relative to strains carrying only one or no prophage. McProf is only capable of lysogeny while BPs is capable of prophage induction in which it excises from the bacterial genome and carries out lytic infection. It is unknown whether BPs lytic or lysogenic infection triggers increased antibiotic resistance. We hypothesize that BPs lytic infection activates McProf gene products that drive changes in antibiotic resistance. To determine which BPs lifecycle drives this process, we used RNAseq to discern the lytic gene expression profile of BPs in M. chelonae. whiB7 expression was measured in M. chelonae in the presence and absence of McProf during lytic BPs infection. whiB7 is upregulated in strains of M. chelonae carrying McProf while expression remains low in strains lacking McProf. A double lysogen of M. chelonae (BPs, McProf) that overexpresses the BPs immunity repressor has diminished induction events and low whiB7 expression relative to non-recombinant M. chelonae double lysogens. Taken together, these data show that prophage can sense and respond to bacterial stress such as phage lytic infection and increase survival during drug exposure.
1016. Determining the Role of Paratox in Streptococcus agalactiae: Virulence and Bacterial Fitness
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Hannah Maurais, Caitlin Wiafe-Kwakye, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Bacteriophages are viruses that infect bacteria. When introduced into the cell, they can insert their DNA into the host cell’s genome and become prophages. Prophages have been found in Streptococcus agalactiae (Group B Streptococcus or GBS), a human pathogen that colonizes the vagnial tract of 25% of pregnant women, and can cause life threatening illnesses in infants such as sepsis or meningitis. Prophages often contribute to bacterial virulence and fitness, but it is currently not known what specifically in the prophages of GBS is causing virulence. A gene of interest, called Paratox, has been found in the majority of GBS prophages and has contributed to natural competence in other species of Streptococcus, however, we currently have no information on what Paratox is doing in GBS. The gene adjacent to Paratox and transcribed in the opposite direction encodes a protein called the Holin-like toxin. In this proposal, we will be looking at the conditions in which Paratox and the Holin-like are expressed to determine when they are active in the cell. In addition, we will determine what effect these phage-encoded proteins have on bacterial fitness and if they contribute to GBS virulence. The results from this study will provide new information on how a prophage gene can contribute to overall virulence and bacterial survival.
1017. JC Polyomavirus Infection is Reduced by Repurposed Therapeutics
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Avery Bond, Mason Crocker, Michael Wilczek, Nicholas Leclerc, Melissa Maginnis
Graduate Student Presentation
Faculty Mentor: Melissa Maginnis
Abstract: JC polyomavirus (JCPyV) infects up to 80% of the human population, with healthy individuals developing a persistent, asymptomatic infection in the kidneys. In severe cases of immunosuppression, JCPyV can spread from the kidneys to the brain and cause a lytic infection of glial cells, resulting in the disease progressive multifocal leukoencephalopathy (PML). Progression of PML leads to extreme cognitive dysfunction and debilitation and is ultimately fatal. Because there are no approved treatments for this disease, continued research on JCPyV and PML is crucial. In an effort to identify potential therapeutics for PML, the Maginnis laboratory performed a large-scale drug screen using the National Institutes of Health Clinical Collection (NIH-CC). Glial cells were treated with drugs and small molecule inhibitors, infected with JCPyV, and viral infectivity was assayed via high-throughput In-Cell Western assays. Results demonstrated that multiple FDA-approved drugs from various drug classes reduced JCPyV infection. Drug categories with the largest number of “hits” include receptor agonists/antagonists, calcium signaling-related drugs, and enzyme inhibitors. Further characterization of calcium channel blockers and calmodulin inhibitors through viral infectivity assays supports a role for calcium signaling during JCPyV infection. Potential antivirals for JCPyV infection and PML will be identified through additional detailed characterization of hits. Repurposing existing treatments is an effective method for discovery of antiviral therapies, and thus exploring pre-approved drugs from the NIH-CC is a promising route for identifying treatments for PML.
1018. Interactions Between Co-habitating Prophages Increases Expression of Mycobacterial Intrinsic Resistance Gene, whiB7
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Sarah McCallister, Matthew Cox, Jaycee Cushman, Keith Hutchison, Joshua B Kelley, Sally Molloy
Graduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Prophage, integrated viral genomes, are known to increase antibiotic resistance of bacterial pathogens. Non-tuberculosis mycobacteria such as Mycobacterium abscessus, causes pulmonary and disseminating infections that are often totally drug resistant. Most M. abscessus isolates carry one or more prophages but their role in intrinsic antibiotic resistance is not yet known. We have demonstrated that M. chelonae, a close relative of M. abscessus, has higher antibiotic resistance and expression of a conserved mycobacterial regulator of antibiotic resistance genes, whiB7, increases in the presence of two prophage genomes. The first prophage, McProf, only carries out lysogenic infection of M. chelonae. The second prophage, BPs, is capable of lysogenic infection but also undergoes induction and lytic infection. We hypothesize that BPs induction activates McProf gene products, such as polymorphic toxin systems, to increase expression of whiB7. We have demonstrated that strictly lytic infections by BPs increases whiB7 expression in the presence of McProf. Inhibiting BPs induction in the M. chelonae double lysogen (BPs, McProf) decreases whiB7 expression. We don’t know whether whiB7 expression increases in the BPs induced cells or through signaling in neighboring lysogenic cells. To determine if BPs induction increases whiB7 expression in cis or in trans we have constructed M. chelonae strains with an mCherry-whiB7 promoter reporter and a BPs-GFP fluorophage that reports lytic gene expression. Using fluorescent microscopy we will monitor BPs induction events and whiB7 expression in double lysogen strains of M. chelonae (BPs, McProf) and in a super M. chelonae lysogen (BPs, McProf) (pMHBPsgp33) strain that has diminished induction events.
1019. Nanoparticles as Local Reporters in Biological Systems: Modeling Signal and Understanding Limitations
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Jeremy Grant, Aimee Co, Michael Mason
Graduate Student Presentation
Faculty Mentor: Michael Mason
Abstract: As early as 2001, advances in engineered nanotechnologies have caused great excitement about the possibility of using SERS-active nanoparticles as inert, non-toxic, non-bleaching alternatives to fluorescent molecules and quantum dots. Now, nearly 20 years later, there exist few practical examples of the use of SERS-active nanoprobes, despite significant levels of funding and many related publications. These previous works failed because they ubiquitously assumed near-optimal behavior in several key probe factors including Raman cross-section (enhancement), nanoparticle surface loading (number of probe species present), and available nanoparticle concentration (number of particles), all of which are attributable to working in a complex, highly non-ideal biological environment. Here we present a simple scalable accounting model which makes it possible to understand the signal limitations apparent in previous attempts at imaging these probes in biology and allows for determination of likely signal limitations, a key consideration for planning future Raman based imaging experiments.
1020. No More Excu-SES: It’s Time to Address Class and Cognitive Function
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Zoe Prats, Angel Boeve, Lily Brown, Madison Landry, Rebecca MacAulay
Undergraduate Student Presentation
Faculty Mentor: Rebecca MacAulay
Abstract: Objective: Lower socioeconomic status (SES) is associated with several negative health outcomes. Although SES encapsulates both material resources (i.e. income and education) and prestige-related characteristics (i.e. subjective social status (SSS)), most brain health studies focus on the former, leading to inconclusive findings in the literature. Previous research suggests that SSS has incremental validity in predicting cognitive outcomes; SSS is therefore a potentially modifiable risk factor for cognitive decline that requires further exploration. Using data from the Maine Aging Behavior & Learning Enrichment (M-ABLE) study, we aimed to determine whether SSS moderates the relationship between income and executive function (EF). Method: Comprehensive neuropsychological testing and clinical interview were used to assess 124 older adults with a mean age of 71 years. PROCESS regression was used to evaluate the proposed moderation models, with age and education as covariates. Results: Correlational analyses found that income and education were positively associated with EF. No significant relationship was observed between SSS and EF. PROCESS regression indicates that SSS does not moderate the relationship between income and EF. Conclusions: While SSS was strongly associated with objective SES, it was not associated with EF. This suggests that reporting bias or a third variable (e.g. self esteem) may account for the additional variance explained by SSS for health above and beyond that of objective SES. Further research is required to understand what factors individuals use to rate their SSS, as this would provide insight into why SSS shows incremental validity with respect to health outcomes.
1021. Overrepresentation of Kidney Development Function Among 937 Genes Associated with Chronic Kidney Disease in 21 Genome-Wide Association Studies Across Multiple Patient Populations.
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Omodasola Adekeye, Benjamin King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Chronic Kidney Disease (CKD) is a global public health burden with high morbidity and mortality rates. There is a high prevalence and incidence of CKD across the globe. 37 million adults in the United States are estimated to have CKD, which makes up approximately 15% of the adult population. The disease presents no symptoms until it progresses to its end-stage, rendering affected patients uninformed of their condition early enough. CKD is a complex disease influenced by genetic and environmental factors. Genome-wide association studies (GWAS) have been used to associate genetic variants (SNPs) with CKD in different populations. We hypothesize that the CKD-associated genes will map to common biological processes that may increase the risk of developing CKD when dysregulated. We compiled the SNPs from 21 GWAS studies and mapped them to genes using Ensembl’s BioMart tool. A total of 1,606 unique SNPs and 937 genes were identified from the studies. The overlapping SNPs and genes from the studies were calculated and visualized using the R/upset package. Gene Ontology (GO) Biological Processes (BP) annotations for the gene sets were reported and analyzed using the DAVID database. A total of 784 GO BP terms were overrepresented among the genes. One of the overrepresented BP terms was kidney development and function, which was commonly annotated to 30 of the 937 genes. Our research provides a comprehensive set of sequence variants and genes that have been associated with kidney function and will help inform future studies of CKD among different populations.
1022. Investigating Disruptions in Axon Guidance in Dystroglycanopathy.
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Kodey Silknitter, Benjamin King, Clarissa Henry
Graduate Student Presentation
Faculty Mentor: Clarissa Henry
Abstract: Protein glycosylation has emerged as a critical function to facilitate axon guidance and the importance of how this function modulates axon guidance in muscular dystrophies is rapidly emerging. The dystroglycan complex is a glycosylated, transmembrane receptor that binds to extracellular proteins and is critical for extracellular matrix protein-myofiber interaction. Dystroglycanopathy is a form of muscular dystrophy in which 1 of the 18 proteins responsible for glycosylating dystroglycan is non-functional. If one of these genes develops a mutation resulting in a disrupted protein, dystroglycanopathy is the result. Patients diagnosed with dystroglycanopathies can experience muscle wasting, developmental delay, and a shortened lifespan. Recent studies have found that when dystroglycan is knocked-out, axon guidance and subsequent muscle innervation are disrupted. Clearly, dystroglycanopathies compromise the function of the neuromuscular system but the role of the dystroglycan glycosylation proteins axon guidance proteins is not well understood. Our preliminary data suggest that primary motor neuron axon guidance and subsequent neuromuscular junction formation is disrupted in multiple forms of dystroglycanopathy. We have generated two, novel, dystroglycanopathy zebrafish models that arise from a mutation in either gmppb or b4gat1, both of which are responsible for dystroglycan glycosylation. Our current hypothesis is that gmppb and b4gat are both required for proper axon guidance. The two zebrafish models display axon guidance disruption that have not previously been reported. Additionally, RNA-seq data indicates that genes associated with axon guidance are significantly down-regulated in gmppb-/- zebrafish. Ultimately, this work will contribute to our understanding of axon guidance and the disease model.
1023. Investigating the Impact of Prophages on Bacterial Fitness of Streptococcus Agalactiae
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Caitlin Wiafe-Kwakye, Sally Molloy, Melody Neely
Graduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Most pathogenic bacteria carry prophages, genome integrated bacterial viruses, that encode genes that improve pathogen fitness and virulence resulting in increased dissemination and infection. Streptococcus agalactiae, a commensal pathogen, often harbors one or more prophages, but their significance in pathogen fitness and virulence is unknown. S. agalactiae is the frequent cause of life-threatening infections in neonates and young infants. However, antibiotic treatment can have long-term negative effects on the microbiota of neonates. By understanding the role of prophages in S. agalactiae virulence, we provide new opportunities to develop alternative treatments. CNCTC 10/84 is a hypervirulent neonatal blood isolate carrying a single prophage within the bacterial genome. To understand the prophage contribution to bacterial fitness, we cured CNCTC 10/84 of its prophage (phage-cured) to compare gene expression and fitness with that of the wildtype strain. To examine differences in virulence we used a zebrafish larval model. Co-infection with both strains simultaneously resulted in the wildtype strain having a competitive advantage over the phage-cured strain, demonstrating a phage-encoded advantage. Additionally, whole-genome transcriptome analysis was performed on the wildtype and phage-cured strains to determine if bacterial gene expression is altered by the prophage. The gene expression analysis indicates that loss of the prophage significantly altered expression of 27.3% of S. agalactiae genes. These results provide insight into the role that prophages play in the disease pathogenesis of S. agalactiae and ultimately may lead to the identification of potential targets for alternative therapeutic approaches.
1024. Differential Expression of Interferon Response Genes in the Innate Immune Response to Influenza A Virus Infection
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Julianna Grampone, Brandy-Lee Soos, Benjamin L. King
Undergraduate Student Presentation
Faculty Mentor: Benjamin L. King
Abstract: An estimated 650,000 deaths occur per year from respiratory diseases associated with seasonal influenza virus infections. Influenza A Virus (IAV) is one of four types of influenza viruses and changes in the viral genome through antigenic drift and shift pose a significant threat to global health. The objective of our study is to understand innate immune response to IAV by comparing differentially expressed interferon response genes (IRGs) using a larval zebrafish model of IAV infection. Zebrafish larvae are an excellent model for the innate immune system as it is functional by 24-48 hours post fertilization and the adaptive immune system does not develop until 2-4 weeks later. The innate immune response to virus infection includes the interferon pathway. Interferons are proteins secreted by an infected cell that signal to nearby cells to resist further infection. Interferons can induce the expression of IRGs that mediate the antiviral response. A previous genetic screen evaluated whether 380 IRGs impacted IAV entry and replication in human cells. We mapped the human IRGs to zebrafish homologs using Ensembl. We assayed the expression of candidate zebrafish IRGs using qPCR in embryos at 6 and 12 hours post infection. One of these genes, interleukin 1 beta (il1b), has important roles in inflammation. Future directions of our research include assaying the expression of additional candidate IRGs to expand our knowledge of interferon signaling following IAV infection.
1025.Determining the Role of Prophage McProf Gene Products in Mycobacterium chelonae Antibiotic Resistance
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Hector Orellana, Sarah McCallister, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacteria presents a huge impact on human health, due to the difficulty in treating drug resistant mycobacterial infections. Mycobacterium abscessus causes pulmonary infections in Cystic Fibrosis patients and is one of the most intrinsically antibiotic resistant bacteria, with a successful treatment rate of only 45%. If we want to improve treatment of these drug resistant pathogens, it will be important to understand the mechanisms of mycobacterial drug resistance. The long-range goal of this project is to understand how genes encoded by viruses that reside in the bacterial genome, called prophage, contribute to mycobacterial drug resistance. The Molloy lab showed that the presence of two prophages McProf and BPs increase antibiotic resistance of the pathogen M. chelonae. We hypothesize that induction of the BPs prophage, interacts with McProf gene products to drive changes in antibiotic resistance. To determine which McProf gene products contributes to antibiotic resistance, we have cloned each of the genes expressed from the McProf genome in the bacterium. Recombinant strains for each of these genes are being tested relative to control strains for changes in antibiotic resistance by minimum inhibitory concentration assays.
1026. The Danger of Prophage and its Effect on the Virulence of Streptococcus Agalactiae
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Caiden Fraser, Caitlin Wiafe-Kwakye, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Naturally occurring prophages were found in 85% of pregnant female reproductive tract isolates of Streptococcus agalactiae (Group B Strep, GBS), which can lead to increased virulence and disease pathogenesis to the neonate, resulting in more difficult treatments and increased mortality. Antibiotics are the only known treatment for GBS, however GBS is becoming increasingly resistant to these antibiotics. Therefore, to find new ways to treat GBS infections, we need to know more about the various prophages carried by these isolates and the proteins they encode. The prophage were analyzed using bioinformatic applications to see if they possessed any genes that were known to be associated with an increased disease pathogenesis and/or increased bacterial fitness. This was done through the process of genome assembly and annotation. Genomes were first sequenced and assembled, then online tools and databases were used to identify the location of genes, and the function of the proteins they encode. PhiDMC64 is one of the isolated prophages being researched. PhiDMC64 was found to contain 68 genes and multiple Toxins, including a Holin like Toxin, Paradox, and a Ntox50. These toxins and toxin antitoxin systems are known to increase virulence due to their ability to degrade foreign substances and protect the cell. It has been found that multiple other prophages isolated from GBS contain these same genes. These genes give a potential target for future research, to help in the fight against GBS.
1027. DMC9 Prophage Characterization and Impact on Group B Streptococcus Virulence
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Katie Southworth, Hannah Maurais, Caitlin Wiafe-Kwakye, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Group B Streptococcus (GBS) is a commensal bacteria that colonizes the vaginal tract of many pregnant women but is an opportunistic pathogen in immunocompromised individuals, which include fetuses and neonates. Colonization of the vaginal tract during pregnancy puts the baby at risk of infection in utero and during labor. To combat this, women colonized with GBS are given high doses of antibiotics during delivery, but that can harm the natural flora and immune systems of both the mother and baby. While not well-analyzed, GBS is known to carry prophages, which are bacterial viruses that insert themselves into the GBS genome and often carry virulence factors. Clinical isolates of GBS were obtained from the vaginal tracts of pregnant women (DMC strains) and found to obtain prophages. phiDMC9 is a cluster C serotype III prophage within DMC9 that likely influences the fitness and virulence of the pathogen, through genes such as paratox that may aid in defense against competing organisms by inhibiting the uptake of new DNA molecules. The phiDMC9 genome is 39,148 base pairs long and carries 55 genes. Its effects will be investigated by comparing the wildtype to a strain that is cured of the prophage in order to observe changes in the resulting bacterial infections in zebrafish. Additionally, a live-dead assay of the two strains will show its influence on bacterial cell membrane integrity. Characterization of phiDMC9 can lead to better knowledge of GBS, as well as improvements in current treatments for the disease.
1028. Continuous Monitoring of Contamination on Surfaces via Structural Color Analysis
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Oisin Biswas, Caitlin Howell
Graduate Student Presentation
Faculty Mentor: Caitlin Howell
Abstract: The automated detection of microbes on surfaces is critical to understanding and maintaining a healthy balance of beneficial microorganisms while reducing or eliminating harmful ones. However, such detection can be extremely challenging in environments where continuous monitoring is difficult, such as surfaces in and around plant growth areas aboard the International Space Station (ISS). Current monitoring methods of surfaces aboard the ISS are both lengthy, expensive, and diminishes valuable time of astronauts. The work in this project took advantage of the optical phenomenon of structural color to develop a rapid, low-cost, and contactless method of surface contamination detection. To accomplish this, a mass-produced material imprinted with a nanostructured pattern capable of exhibiting this structural color phenomenon was used. The diffraction patterns of this material creating these structural color effects were studied, where manual analytical techniques were developed to show quantitative differences in these effects when a faux surface contaminant ¬¬¬ — silicone oil — was present. The developed techniques focused on three main features of interest in the diffraction patterns: light intensity, diffraction pattern length, and color presence. Light intensity was found to be the greatest indicator of surface contamination presence. Yet, with all three techniques, it was possible to detect the silicone oil contaminant down to at least a volume of 1 x 10-1 μL/ 64 cm2. This work lays the foundation for the development of a rapid, low-cost, and contactless method of contamination detection applicable to plant growth areas with the goal of keeping astronauts in space safe.
1029. Characterization of a Group B Streptococcus Prophage
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Robin Southwick, Caitlin Waife-Kwakye, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Group B Streptococcus (GBS) inhabits the gastrointestinal and urogenital tracts of 35% of the healthy population. Gram-positive bacteria represent a leading cause of invasive bacterial infections in newborns. pathogens carry prophages, genome integrated bacterial viruses. Studying prophage-carrying bacteria gives us a better understanding of how bacteria become pathogenic and can save lives and cure diseases. Prophages often encode toxin genes and provide resistances that can make some bacteria more pathogenic and infectious. The goal of this research is to determine how prophages of Streptococcus contribute to bacterial pathogenesis or regulation of host gene expression. DMC69 a vaginal isolate from anonymous pregnant female. The genome was sequenced and the prophage phiDMC69 were extracted using the program Phaster. Genome annotation is done by collecting information such as possible links between similar genes and possible gene functions using gene databases, HHpred, NCBI, BLAST, Topcons, and PECAAN. From the annotation, we learned that phiDMC69 belongs to cluster C phages, has a 36.2% GC content with a total 65 genes. The genome contains a single orpham, a gene with no known homologs. phiDMC69 contains proteins like holin-like toxin and paratox, both of which increase bacterial fitness. By studying and annotating the genes of integrated prophage we can uncover how, why, and perhaps even when, new genetic information caused ordinary benign bacteria to become pathogenic.
1030. MicroRNA Regulation of Neutrophil Inflammation Regulation during Influenza A Virus Infection
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Riley Grindle, Brandy-Lee Soos, Benjamin King
Undergraduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Influenza virus infection causes a substantial inflammatory response by the innate immune system. Neutrophils play a major role in innate immunity where they migrate to the site of infection, clear infection, and then migrate away. Hyperinflammatory responses due to neutrophil overactivation can result in tissue damage. Thus, neutrophil activity must be carefully balanced to reduce tissue damage while still clearing the infection. MicroRNAs (miRNAs) are potent regulators of genes and we hypothesize that miRNAs function to regulate neutrophil function during Influenza A Virus (IAV) infection. Using a zebrafish model of IAV infection, we have been studying to determine when and how neutrophils are being activated. We have measured the expression of a set of candidate miRNAs previously identified to be involved with neutrophil regulation during bacterial infection. Specifically, we have been studying miR-199, miR-722, and miR-146a. Both miR-199 and miR-722 have been described to have roles in neutrophil migration in response to bacterial infection. MiR-146a has been described to regulate Toll-like receptor signaling during bacterial infection. Additionally, we will assay miRNA expression in IAV-infected zebrafish after knocking down two genes with important roles in neutrophil function, ncf1 and cxcl8b. Ongoing preliminary studies in our laboratory have shown that knocking down these genes alters survival of zebrafish embryos following IAV infection. Preliminary results show that there was a significant change in the candidate miRNA expression following IAV infection. Our studies aim to uncover the role of miRNAs in regulating neutrophil function and the overall response to IAV infection.
1031. Characterization of the Cluster MabR Prophages of Mycobacterium abscessus and Mycobacterium chelonae
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Jacob Cote, Colin Welch, Madeline Kimble, Dakota Archambault, John Curtis Ross, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacterium abscessus is one of the most drug-resistant bacteria we know of and is a significant pathogen in cystic fibrosis and immunocompromised patients with low treatment success rates. The majority of clinical M. abscessus isolates carry one or more prophages that are hypothesized to contribute to virulence and bacterial fitness. The prophage McProf was identified in the genome of the Bergey strain of M. chelonae and is distinct from previously described prophages of M. abscessus. The McProf genome increases intrinsic antibiotic resistance of M. chelonae and drives expression of the intrinsic antibiotic resistance gene, whiB7, when superinfected by a second phage. The prevalence of McProf-like genomes in sequenced mycobacterial genomes was bioinformatically determined. Related prophage genomes were identified in 25 clinical isolates of M. abscessus and assigned to the novel cluster, MabR. The MabR genomes share less than 10% gene content with previously described prophages; however, they share features typical of M. abscessus prophages, including polymorphic toxin immunity (PT-Imm) systems, which we hypothesize could be involved in the observed antibiotic resistance increases in our model.
1032. Regulation of Microtubule Dynamics During the Pheromone Response in Saccharomyces Cerevisiae
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Loren Genrich, Joshua Kelley, Cory Johnson
Undergraduate Student Presentation
Faculty Mentor: Joshua Kelley
Abstract: The budding yeast, Saccharomyces cerevisiae, responds to pheromone through a G-protein coupled receptor (GPCR) signaling pathway. Upon receptor activation, the heterotrimeric G-protein dissociates and initializes separate downstream signals through the Gα and Gβγ subunits. When responding to pheromone, cells either elongate towards the source of pheromone or form mating projections known as “shmoos.” The kinesin Kar3 is located at the tip of the shmoo and regulates plus-end polymerization of microtubules via interaction with Gα, which has been shown to negatively regulate microtubule assembly. We used a hyperactive Gα mutant that possesses a single amino acid mutation at position 302, where the glycine (G) is converted to a serine (S). This renders the Gα unable to bind to the regulator of G-protein signaling (RGS), which prevents RGS-induced acceleration of the intrinsic GTPase activity of Gα, the primary negative regulator of G-protein signaling. During pheromone-induced elongation, the nucleus aligns along the axis of polarity (toward the leading edge of the mating projection). This nuclear positioning is dependent on Gpa1 regulation of Kar3. Our preliminary data shows that nuclear orientation during gradient tracking in cells containing the hyperactive Gα varies considerably over time, compared to wild-type. Therefore we hypothesized that microtubule dynamics contribute to normal gradient tracking through a Gα-dependent mechanism during the yeast pheromone response. Using live cell microscopy, microfluidics, and image analysis, I will test the hypothesis that Gα control of Kar3 is important for polarized growth.
1033. VO2 Max Testing
Submission Type: Exhibit
Submission Category: Biomedical Sciences
Author(s): Evan Bess, Cole Perry, Thomas Bowie, Oliviah Damboise, Michael Mason
Undergraduate Student Presentation
Faculty Mentor: Michael Mason
Abstract: VO2 max testing is used to provide feedback on overall cardiorespiratory fitness by measuring the maximum rate oxygen is used during intense activity; however current testing equipment is limited by long tubes, uncomfortable masks, difficult cleaning procedures, cumbersome software, and expensive equipment. The goal of the project is to redesign the VO2 max testing system by eliminating tubing, modularizing the design, using more affordable sensors, and reducing the weight. The new testing system was fabricated by 3D printing components, Arduino boards, microphone, oxygen sensors, and gas flow meter which is controlled by LabVIEW 2019 software package. The microphone was used to acquire audio data that provided the frequency of breathing. The oxygen sensors were used in conjunction with an Arduino and LabVIEW virtual instrument (VI) to gather oxygen concentration data. The gas flow meter was used to monitor respiratory flow rate through a LabVIEW VI. Based on the results, this novel approach shows the potential to address existing VO2 max testing problems by reducing the complexity of the design, reducing the cost to the consumer, and eliminating the long tubing and uncomfortable masks.
1034. Evaluating Ca2+ Related Drugs for Inhibition of JC Polyomavirus Infection
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Amanda Sandberg, Avery Bond, Melissa Maginnis
Undergraduate Student Presentation
Faculty Mentor: Melissa Maginnis
Abstract: Progressive multifocal leukoencephalopathy (PML), caused by JC polyomavirus (JCPyV) infection in glial cells, is a rapid, deteriorating, and fatal brain disease with no known cure. Approximately 80% of the world’s population is infected with JCPyV, and for most the infection remains a persistent asymptomatic infection of the kidneys, but for individuals with suppressed immune systems the infection can migrate to the central nervous system and cause PML. Prior research has found that drugs modulating the intracellular flux of calcium (Ca2+) can reduce JCPyV infection, thus suggesting that Ca2+ signaling can be an important factor in driving a successful JCPyV infection in host cells. The goal of this project is to evaluate the inhibitory effect of tetrandrine, a nicotinic acid dinucleotide phosphate (NAADP) -sensitive two-pore Ca2+ channel drug, on JCPyV infection. Glial cells were treated with tetrandrine at concentrations ranging from of 2 to 7 μM and infected with JCPyV. Infectivity was measured using an epifluorescence microscopy-based viral infectivity assay. Preliminary research suggests a decrease in JCPyV infection when cells are pre-treated with tetrandrine. The lack of effective treatments for PML highlights a crucial need for new anti-viral therapies. Evaluating calcium-related inhibitors and drugs, such as tetrandrine, for reduction of JCPyV infection contributes to the critical need for discovery of new therapeutic targets for PML.
1035. Quantifying Birefringence Images of Zebrafish Using a Mix of Deep Neural Networks and Image Analysis Tools
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Ahmed Almaghasilah, Clarissa Henry, Joshua Kelley
Graduate Student Presentation
Faculty Mentor: Clarissa Henry
Abstract: In Henry’s lab at University of Maine, we study muscular dystrophies such as Duchenne Muscular Dystrophy, a genetic disorder that results in progressive weakening and loss of muscle fibers and can lead to early death in children. We use birefringence, a non-invasive, live-imaging technique that uses polarized light to visualize muscle fibers of zebrafish. This technique allows us to assess the effectiveness of several therapies, which attempt to improve the functionality and structure of muscle fibers, applied on zebrafish with muscular dystrophies. The birefringence images are quantified by highlighting the zebrafish first and then calculating the mean gray value. However, the experiments typically generate a huge volume of images and quantifying these images manually can be an extremely time-consuming process. Analyzing data manually is also subjective and can result in variation, which can lead to the wrong conclusion. In addition, to the best of our knowledge, no one has ever developed a software nor an algorithm to automate the quantification of birefringence images. In the past, we trained a convolutional neural network (CNN) to automate the process but CNN did not yield reliable and high accuracy outcomes. For those reasons, we decided to apply image analysis techniques such as background contrast and several built-in functions on MATLAB while keeping the CNN predictions to enhance the final results. This novel approach has delivered better results than using CNN alone. The developed algorithm is able to discard noises that are usually mislabeled as zebrafish by the CNN and thus increasing the accuracy of the mean gray value. We believe our method will one day be the new standard in evaluating and quantifying birefringence images in the field of biomedical research.
1036. Role of the HU177 Cryptic Collagen Epitope in Differentially Controlling Breast Tumor Cell Behavior
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Jordan Miner, Peter Brooks
Graduate Student Presentation
Faculty Mentor: Peter Brooks
Abstract: The growth and metastatic spread of malignant tumors is controlled by the stromal microenvironment and the extracellular matrix (ECM). However, it is challenging to develop clinically relevant strategies to disrupt the pro-tumorigenic mechanisms controlled by the ECM. Therefore, it is important to understand how stromal cells and structural changes within the ECM function cooperatively to facilitate the creation of a tumor permissive and immunosuppressive microenvironment that regulates tumor progression. The Brooks Lab has identified a unique cryptic collagen epitope (HU177). Phase-1 human clinical trials evaluating the anti-tumor activity of targeting the HU177 epitope have shown encouraging results. Therefore, there is a need to understand the mechanisms that contribute to this activity. During tumor growth, matrix metalloproteinases (MMPs) secreted by tumor and endothelial cells remodel and denature collagen in the ECM which leads to exposure of the cryptic sites. These sites play a role in tumor cell adhesion, migration, and proliferation and can be bound by the anti-HU177 antibody. 4T1 cells are a triple-negative tumor-derived cell line and are a model for human breast cancer. It was found that the humanized version of the HU177 antibody (D93) was able to specifically bind to denatured collagen I and IV and negatively impact cell adhesion for both collagen types. Interestingly, we found that 4T1 cells actually secrete denatured collagen themselves. Ultimately, D93 was shown to regulate 4T1 cell behavior through denatured collagen I and IV, aiding in the explanation of its anti-tumor activity.
1037. Testing Effects of Newly Isolated Prophage on Mycobacterial Drug Resistance
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Andre Daigle, Katelyn Amero, Eleanor Carrolton, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacterium abscessus is the most isolated pathogen from cystic fibrosis patients and is often completely resistant to antibiotics, with only a 45.6% successful treatment rate (1). Incidence and deaths from non-tuberculous mycobacterial (NTM) diseases have been steadily increasing globally, both in immunocompromised and healthy individuals (2). Understanding the resistance mechanisms of NTM to antimicrobial drugs will be important for improving treatments of bacterial infections. Bacteriophages, through a temperate lifecycle, can integrate into bacterial genomes as a prophage to increase pathogen virulence. The Molloy lab has demonstrated that two types of prophage contribute to intrinsic resistance in M. chelonae, a pathogen closely related to M. abscessus. Currently, we only have two phage isolates that infect M. chelonae, limiting our understanding of their impact on drug resistance. To broaden this knowledge, we isolated two novel temperate phages from the soil, Aegeus and Baudelaire, on the host M. chelonae. The Baudelaire genome was sequenced and is 74,913 nucleotides in length and encodes 126 genes. Baudelaire is most closely related to cluster L phages isolated on non-pathogenic M. smegmatis but is unique among cluster L phages and was assigned to a novel subcluster, L5. Although Baudelaire is related to M. smegmatis phages, it is unable to infect M. smegmatis and its genome is enriched in toxin systems that are more typical in M. abscessus prophages. To study the effect of Aegeus and Baudelaire on mycobacterial drug resistance, the isolated M. chelonae lysogens will be compared to non-lysogen strains for antibiotic susceptibility.
1038. The Impact of Calmodulin Signaling on JC Polyomavirus Infection
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Aiden Pike, Michael Wilczek, Melissa Maginnis
Undergraduate Student Presentation
Faculty Mentor: Melissa Maginnis
Abstract: JC polyomavirus (JCPyV) infects up to 80% of the population. In healthy individuals, JCPyV establishes a persistent, asymptomatic kidney infection. In immunocompromised individuals, JCPyV traffics to the brain and causes progressive multifocal leukoencephalopathy (PML). This fatal, demyelinating disease is characterized by the destruction of glial cells, development of white matter lesions, and the loss of vision, speech, and motor function. The mechanisms by which JCPyV causes PML remain poorly understood, and there is no approved cure, yet defining infection-regulating host factors can identify new treatment targets. Preliminary data from the Maginnis Laboratory suggests that JCPyV infection modulates calcium (Ca2+) and calmodulin signaling pathways, and altering these pathways reduces infection. The goal of this project is to determine whether calmodulin-dependent protein kinases (CaMKs) regulate JCPyV infection. CaMKs are activated upon intracellular Ca2+ release and implicated in gene expression regulation by stimulating transcription factors. CaMKIV is present in higher concentrations in brain tissue and translocates into the nucleus, stimulating transcription factor NF-κB. Interestingly, JCPyV possesses NF-κB-binding sites in the non-coding control region (NCCR) of the viral genome, which undergoes frequent recombination during viral pathogenesis. Transcriptomic data from JCPyV-infected cells suggests that CaMKIV is differentially expressed throughout infection. Current studies seek to define whether reduction of cellular CAMKIV impacts JCPyV infection and how CaMKIV affects nuclear NF-κB localization during infection. Understanding the impact of Ca2+ signaling on gene expression during JCPyV infection will improve our understanding of virus-host cell interactions and potentially lead to novel treatment targets.
1039. Aging and Connectivity in Dendritic Spines
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Marissa Ruzga, Erik Bloss
Graduate Student Presentation
Faculty Mentor: Erik Bloss
Abstract: Neurons have structural and functional characteristics that vary across the brain (Ottersen, O., Helm, P., 2002). This project focuses on comparing how different neurons respond to aging in terms of baseline phenotypic characteristics, including the density of dendritic spine synapses. We performed this analysis across two distinct sets of neurons: those that originate in the cortex and project to the thalamus and those that project to the amygdala. On each neuron, dendritic spines are small structures on the postsynaptic dendrites that represent the site of excitatory synapses. It has been shown that spine densities and average spine shape may change with age and may have correlation with performance on learning tests (Dumitriu, Hao et al., 2010). Retrograde viruses were injected into either the amygdala or the thalamus of young or aged mice. Only the cortex data will be presented here. After the tissue was fixed and captured with confocal fluorescence imaging, the spine densities and diameters were recorded using computer reconstruction programs. In the group of neurons that projected to the amygdala, aged animals were found to have a significantly lower density of spines and significantly smaller spine head diameters in one region. In contrast, those that projected to the thalamus showed no significant differences in spine density with age. Future work will examine projections in the hippocampus, as well as expand the scope with further investigation into the potential changes in spine size in respective regions.
1040. Spatial Frequency Domain Imaging Applications in Diabetic Testing
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Christian Crane, Chisom Orakwue, Anna Baldwin, Karissa Tilbury
Graduate Student Presentation
Faculty Mentor: Karissa Tilbury
Abstract: Diabetic neuropathy, vascular disease, and diabetic foot ulcers are key disease states of long term mismanaged or poorly controlled diabetes often impacting extremities such as fingers or feet. Neuropathy is one of the most common complications involving roughly 50% of diabetic patients over their lifetime. Following neuropathy, ulcers may form on the base of the feet degrading nearby tissue causing approximately 28% of ulcers to result in some form of lower extremity amputation. These conditions are often tested clinically by examination of sensation in the foot, localized perfusion pressure, transcutaneous oxygen pressure, dorsal foot pulses, and ankle or toe blood pressure metrics. Many of these widely accepted tests are often invasive, expensive, or incur risks such as X-ray and CT radiation. Through the use of spatial frequency domain imaging, data may be collected non-invasively to better understand physiologic conditions including regional oxygenation. Healthy, diabetic, and neuropathy volunteers were tested in three different loading conditions to better understand how pressure impacts physiology on the base of the foot. There has been limited research on quantifying pressure induced vasodilation in diabetics over a large field of view which we hope to elucidate. From initial data collection, the ability to see potential perfusion changes in the base of the foot is confirmed. Further research is needed and will be continued in the Tilbury biomedical engineering optics lab to understand the potential application of SFDI for diabetic testing.
1041. Effect of Pharmaceutical Agent Cetylpyridinium Chloride on Early Tyrosine Phosphorylation Events in Immune Mast Cells
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Marissa Paine, Bright Obeng, Lucas Bennett, Patrick Fleming, Julie Gosse
Undergraduate Student Presentation
Faculty Mentor: Julie Gosse
Abstract: Cetylpyridinium chloride (CPC) is a positively-charged antimicrobial used widely in consumer products and agricultural processes at concentrations up to 3 millimolar, exposing much of the U.S. populace to significant levels of CPC. There is minimal information on CPC’s eukaryotic toxicology; hence, there is an urgent need for research. Mast cells, ubiquitous throughout the human body, are implicated in many diseases and key players in normal immune and nervous system functioning. We have demonstrated that low-µM doses of CPC potently inhibit the antigen (Ag)-stimulated functions of RBL-2H3 mast cells, including degranulation. We have investigated the molecular mechanism underlying CPC inhibition of degranulation. Following 30 min pre-exposure, CPC drastically inhibits Ag-stimulated Ca2+ efflux from the endoplasmic reticulum and also external Ca2+ entry into the cytosol, which is necessary for degranulation. These Ca2+ dynamics are triggered by early tyrosine phosphorylation events, including Syk and LAT phosphorylation. Using In-Cell Western, global tyrosine phosphorylation was inhibited by 30 min CPC pre-exposure. A more detailed probing using Western Blot showed that CPC does not inhibit tyrosine phosphorylation, including that of Syk and LAT. Analysis with ELISA confirmed that CPC does not inhibit the phosphorylation of Syk. Additional investigation will be done using varying antigen and CPC doses. This work provides molecular mechanisms underlying the effects of CPC on immune signaling. It allows the prediction of CPC effects on cell types that share similar signaling elements, such as T cells.
1042. Building Literacy in Microscopy and Reproducible Image Analysis
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Dominic Crowley, Loren Genrich, Marcus Ratz, Sophie Trafton, Karissa Tilbury, Frédéric Bonnet
Undergraduate Student Presentation
Faculty Mentor: Karissa Tilbury
Abstract: Microscopy is a ubiquitous tool to observe and quantify biological processes. Image processing through programs such as FIJI (ImageJ) can be used for data quantification and can improve the standard of microscopic images in data presentation. Despite the importance of these methods, proper training in the fundamentals of microscopy is limited. As the emphasis of microscopy images shifts from qualitative to quantitative, knowledge of the impact of image acquisition and processing is critical in creating quantitative, reproducible data. Here, data is presented from a microscopy course where we were educated in the fundamentals of image collection and quantitative analysis. We applied this tool-set to two distinct models: characterization of murine renal cells during drug response and therapeutic reversal of muscular aging using a C. elegans model system. Digital images of the renal tissue were produced using wide-field fluorescence microscopy and were then processed in FIJI; in these images, the brightness of the cell nuclei is associated with the amount of DNA. The renal cells treated with the drug had less intense nuclei signals, indicating a positive response. In the C. elegans muscular aging model, we used bright-field microscopy, where the worms were segmented in FIJI via pixel intensities. Segmented worms were then identified and tracked during a time-course to quantify worm speed. Using this assay, we found that the drug was able to restore muscular endurance in aged worms. In both models, the use of FIJI allowed for qualitative images to be quantified through a reproducible process.
1043. Biometric Enabled Aviation Helmet
Submission Type: Exhibit
Submission Category: Biomedical Sciences
Author(s): Naomi Kihn, Haley Florio, Sadie Denico, Giordano Luciani, Karissa Tilbury
Undergraduate Student Presentation
Faculty Mentor: Karissa Tilbury
Abstract: The number of fatigue-related aviation accidents is low, however, when they do occur, they can be catastrophic. Currently, no device can provide quantitative information about the status of pilots during their flights. The purpose of this capstone project is to create a device that provides a way to assess and monitor an aviation pilot’s level of alertness remotely for flight safety. To accomplish this, we built a wearable sensor suite that consists of the following: a thermistor, camera module, accelerometer, and a heart rate and oximeter. This suite will be compatible with a pilot’s headset or helmet. The thermistor will be placed directly on the skin to measure skin temperature. The camera will be placed away from the face to capture blinking rates. The accelerometer will be positioned on the back of the head to measure unexpected head movement. The heart rate and oximeter will be placed on the temple. Each sensor was tested and calibrated individually. To understand the effects of fatigue, results will be compared against the individual’s baseline readings. When worn, the sensor suite will monitor the pilot’s status in real-time. Our design illustrates that with a simple wearable sensor suite, quantitative data can be noninvasively tracked for the duration of their flight. This data can be used to assess the pilot’s potential fatigue. The long-term goal for this device is to collect data to be able to better predict the fatigue level of pilots so that preventative measures can be taken to reduce the risk of fatigue-related errors.
1044. The Impact of Cxcr4/Cxcl12 on Migrating Muscle Precursors
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Sara Loiselle, Jared Talbot
Undergraduate Student Presentation
Faculty Mentor: Jared Talbot
Abstract: I investigated the effects of the chemokine gene Cxcr4 and its ligand Cxcl12a on the migration of muscle precursor cells in Zebrafish. Zebrafish are an ideal organism for this study because their development is visible through their embryos and they only have 3 major migratory muscle streams: neck, fins and chest muscles. Previous studies have suggested that Cxcr4/Cxcl12a plays an integral role in the migration of muscle cells and is required for guiding muscle precursor cells to the pectoral and pelvic girl in birds and mammals. It remains unclear whether Cxcr4/Cxcl12a function is conserved in boney vertebrates and if it acts globally to attract cells during migration. We hypothesized that the ligand-receptor pair Cxcl12a-Cxcr4 stimulates muscle precursor migration and growth in all hypaxial streams. Over the summer I genotyped Cxcl12a null mutants and examined the hypaxial muscles. I found reduced hypaxial muscle size in the cxcl12a mutant. Each muscle (fin, neck, and chest) in the cxcl12a null fish was about ¾ the size as the WT fish. My research into a Cxcr4-inhibitor, MSX122 showed a comparable reduction of all three muscle streams in Zebrafish. Together these findings suggest that Cxcr4/Cxcl12a plays an role in the outgrowth of hypaxial muscle precursor streams; however, hypaxial muscles can form in the absence of Cxcr4/Cxcl12a signaling which suggests that there are other important cues guiding these migratory cells. This work was supported in part by a CUGR fellowship (Summer 2021).
1045. Neuronal Transient Receptor Potential Melastatin-8 Cation (TRPM8) Channel may Regulate Bone Mass via Mesenchymal Stem/Stromal Cell Maintenance
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Audrie Langlais, Adriana Lelis Carvalho, Katherine Motyl
Graduate Student Presentation
Faculty Mentor: Katherine Motyl
Abstract: Transient receptor potential cation channels (TRP) are expressed by osteoblasts (bone mineralizing cell) and osteoclasts (bone resorbing cell) to regulate cell differentiation. TRP channels are also expressed by sensory neurons which innervate peripheral tissues and can indirectly regulate osteoclasts and osteoblasts. Our lab is the first to identify a bone phenotype in mice lacking transient receptor potential melastatin-8 (Trpm8-/-). Trpm8-/- males have low vertebral bone volume fraction (bone volume/total volume) and decreased trabecular thickness determined by microcomputed tomography. Osteoblasts differentiate from Mesenchymal Stem/Stromal Cells (MSSCs) and reports by others show TRPM8 expression in a murine cell line (MC3T3-E1) and primary human MSSCs. This suggested the mechanism of bone loss could be due to changes in MSSC renewal and osteoblast differentiation. To determine if MSSCs are altered in Trpm8-/- mice, we cultured bone marrow stromal cells (BMSC’s). Compared to wildtype controls, Trpm8-/- mice have reduced colony formation determined by crystal violet staining. Surprisingly, we could not detect Trpm8 expression in MC3T3-E1 cells by qPCR. Furthermore, treatment of BMSCs from C57BL6/J mice with WS-12, a selective TRPM8 agonist, did not influence cell growth. Lastly, in situ hybridization of Trpm8 mRNA in vertebrae shows expression in distinct subpopulations of dorsal root ganglion sensory neurons as expected, but not adjacent trabecular bone. Future studies will test if reduced cell proliferation or increased apoptosis occurs in Trpm8-/- MSSCs. Overall, our results support an indirect mechanism of Trpm8 signaling in sensory neurons on bone formation, rather than signaling within MSSCs.
1046. Smart Paper Diagnostics
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Emma Sperry, Kara Frasier, Dillon Kelley, Francois Rukumbuzi, James Beaupre
Undergraduate Student Presentation
Faculty Mentor: James Beaupre
Abstract: Separating components of blood, such as plasma and erythrocytes, is important for diagnostic testing as it minimizes the interference of other cells when analyzing specific cell counts in order for health professionals to determine a diagnosis. Existing blood separation and diagnostic techniques, such as centrifugation, come with various downsides such as high costs and large stationary equipment, often leaving developing countries with little to no access to blood separation and testing. This project aims to develop a microfluidic device capable of separating particles for medical personnel looking to isolate samples in a way that is inexpensive to produce and portable. To do this, a microseparator was created in SolidWorks that utilizes a cross-flow design to separate two different-sized particles. The flow profile and particle tracing were modeled in COMSOL Multiphysics and Ansys. The results predicted the design would be effective, and most of the separation would occur at the beginning of the device. The design was 3D printed as a mold for silicone caulking and PDMS to create prototypes. Plexiglass was sealed on top of the prototype which allowed for visualization of the movement of particles. Particle separation was measured in terms of percentage of sample filtered, time to complete separation, the volume of leakage and backflow, and flow efficiency using ImageJ for image analysis. These experiments will allow analysis of particle behavior in a cross-flow microseparator and further design development could lead to more accessible blood separation techniques in developing countries.
1047. Interferon Response Factor 7 is a Transcriptional Target of Nuclear Factor Kappa B (NFkB)-Mediated Inflammation Following Influenza A Virus Infection
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Wyatt Cannell, Emma Boudreaux, Sarah MacLeod, Brandy-Lee Soos, Benjamin King
Undergraduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Between 2010 and 2020 approximately the U.S. recorded 12,000-52,000 influenza-related fatalities annually. Although vaccines for this infection are widely administered, the diversity of influenza strains that circulate seasonally among varying populations can render them less effective. In order to develop therapies to better prevent severe illness, further research regarding how the immune system responds to influenza infection is needed. One immune response of interest is the over-activation of neutrophils, the first immune cells to respond to infection and initiate an inflammatory response. This over-activation can cause damage to many different tissues, but the characterization of the mechanisms required to balance this effect remains incomplete. However, nuclear factor kappa B (NFkB) is a transcription factor known to regulate inflammation by activating and deactivating target genes. This study tested the hypothesis that NFkB activation initiates an inflammatory response which includes a set of target genes that regulate neutrophil function in response to influenza A virus (IAV) infection. Since embryos only have functional innate immune cells, including neutrophils, this study used IAV-infected zebrafish embryos. Using data collected from this model, RNA sequencing data was analyzed and 76 NFkB target genes were found to be differentially expressed at 6 hours post-infection (hpi). Additionally, Interferon response factor 7 (irf7), a gene that has been shown to regulate immune response to RNA viruses like IAV, was differentially expressed at 6 and 12 hpi using quantitative real-time PCR. This study provides the necessary foundational data regarding the regulatory mechanisms of neutrophils during IAV infection.
1048. Nociceptor Sensitivity in Larval and Adult Drosophila
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Christine Hale, Samia Pratt, Julie Moulton, Geoffrey Ganter, Emma Boudreaux
Graduate Student Presentation
Faculty Mentor: Geoffrey Ganter
Abstract: Nociceptive sensitization underlies and perpetuates chronic pain, a condition that affects ~50 million adults nationwide. With many treatment options for chronic pain, such as opioid analgesics, carrying numerous deleterious side effects, research into safer and more effective treatment options is crucial. Recently, a nociceptive sensitization model was developed using Drosophila melanogaster larvae, in which UV-injured or genetically modified animals become hyper or hypo-sensitive. Using this model, the necessity and sufficiency of a novel pathway, the Bone Morphogenetic Protein (BMP) pathway, functioning in the nociceptors, was revealed. We have continued to build upon this knowledge to reveal a more complete mechanism for how nociceptive sensitization occurs by investigating into the potential roles of other novel genes/signaling pathways including, arm, a component within the Wnt/Wg signaling pathway. At present, our findings indicate Arm to be a facilitator in controlling nociceptor sensitivity. In addition to our focus on mechanisms that promote hypersensitivity, we also propose to expand our efforts by bringing new focus to more chronic nociceptor sensitization conditions. To facilitate these efforts, because the larval stages of fruit fly development are relatively brief, we are also developing a methodology that allows longer term experimentation of nociceptive sensitization after injury in adult fruit flies. Recent efforts toward this goal include mapping the adult fruit fly nociceptor distribution by confocal microscopy and developing thermonociception methods for use with adult flies. Our ultimate aim is to better understand the mechanisms of nociceptive sensitization so that better treatment options for chronic pain may be revealed.
1049. Life-long Dietary Restrictions have Negligible and Potentially Damaging Effects on Late-life Cognitive Performance in the Diversity Outbred Mouse Population
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Andrew Ouellette, Niran Hadad , Andrew Deighan, Laura Robinson, Adam Freund, Gary Churchill, Catherine Kaczorowski
Graduate Student Presentation
Faculty Mentor: Catherine Kaczorowski
Abstract: Although aging remains the greatest risk factor for developing cognitive decline and Alzheimer’s dementia, to date, no anti-aging interventions have been proven to modify the onset or progression of cognitive symptoms in the elderly population. Several studies have reported that intermittent fasting (IF) or caloric restriction (CR) interventions, which reliably increase lifespan across a variety of model organisms and humans, can also improve late-life cognitive outcomes, while others have reported no or limited beneficial effect of CR and IF on cognition. Here, we compare the effects of 4 feeding paradigms (1 day IF, 2 day IF, 20% CR and 40% CR) to ad libitum (AL) on Y-maze working memory decline (longitudinal 10 vs 22 mo) and long-term memory using contextual fear memory (CFM, 24 mo) in a large population Diversity Outbred (DO) mice that model the complex genetic architecture of humans. As expected, we observed a significant increase in survival in CR and IF groups at 24 months compared to mice fed AL, however there was no benefit of 20% CR and 1 or 2 day IF on working memory or long-term CFM. Furthermore, we report that severe 40% CR has damaging effects on CFM at 24 months of age. Using Quantitative Trait Loci mapping we identified the gene Slc16a7, which codes the lactate and pyruvate transporter protein MCT2 (Monocarboxylate transporter 2), to be associated with late-life long-term memory outcomes in mice on lifespan promoting feeding paradigms. We find that strongly associated variants from DO founders strains within the Slc16a7 locus confer enhanced late-life long-term memory outcomes. Overall, limited utility of dieting and fasting on memory improvement in mice that recapitulate genetic diversity in the human population highlights the need for anti-aging therapeutics that promote cognitive function.
1050. Optimization of Proteolytic Collagen Degradations to Enable Identification of SHG Signatures Associated with Proteolytic Degradation
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Madison Mueth, Jordan Miner, Karissa Tilbury
Graduate Student Presentation
Faculty Mentor: Karissa Tilbury
Abstract: The dynamics of collagen remodeling within the tumor microenvironment are critical for tumor initiation, promotion, and metastasis. Tumorigenic microenvironments frequently are characterized by fibrosis and stiff collagen; however, matrix metalloproteinases (MMPs), enzymes that degrade the extracellular matrix proteins including collagen, are commonly upregulated. Collagen imaging studies using Second Harmonic Generation (SHG) imaging demonstrate differences between normal and cancerous tissues; however, these studies lack specificity of the dominant state of collagen remodeling. Here we develop a collagen gel model exclusively focused on the proteolytic degradation of collagen to identify SHG signatures associated with proteolytic degradation. Collagen gels were degraded using a broad-spectrum collagenase. Collagen degradation was confirmed using the autofluorescence of exposed tyrosine (EX 270 nm/EM 330 nm). Controlled collagen degradation using EDTA, a collagenase inhibitor, resulted in partially degraded collagen gels based on stable tyrosine autofluorescence intensity and visual inspection. The partially degraded collagen gels were imaged using SHG microscopy and compared to fully intact collagen gels. Visually, the partially degraded collagen gels have more compact, shorter fiber structures. Further analysis of the directionality of the SHG signal is underway. The directionality of SHG is sensitive to fibril packing within collagen fibers and is more closely aligned with the size-scale of cellular interaction with collagen fibers. This knowledge will improve our understanding of the dynamics of collagen remodeling which is critical for the development of novel therapeutics.
1051. Novel Gordonia Phage StarStruck: A Shining Light for Discovery
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Julia Coombs, Eleanor Carrolton, Wyatt Cannell, Addie Gambol, Mchenna Martin, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Filamentous bacteria like Gordonia terrae pose economic, environmental, and health risks by diminishing wastewater treatment efficiency. Bacteriophages (phage), viruses which infect bacteria, can be used to reduce G. terrae populations improving wastewater treatment. Phage are the most abundant biological entities representing 1031 particles in Earth’s biosphere, but only 634 G. terrae phage have been sequenced. StarStruck, a novel phage, was isolated through an enriched G. terrae sample and sequenced for characterization of it’s genome to better understand phage diversity. Phamerator, HHPRED, PhagesDB, and NCBI Blast were all used to annotate the genome of StarStruck. StarStruck is a cluster CR2 phage, meaning it shares more than 35% of its gene content with cluster members. StarStruck’s genome is 68,128 bp long, contains 91 genes, and has a 65.4% GC content. StarStruck is a lytic phage which lyses the cells it infects, while most G. terrae phages are temperate and integrate genomes with their hosts. As a lytic phage, StarStruck encodes lysin A (gp 49/50), lysin B (gp18), holin (gp15), and a HicA toxin (gp6). Despite being a lytic phage, StarStruck encodes a temperate resolvase (gp59) associated with excising from the host genome, representing a potential horizontal gene transfer indicative of phage evolution and diversity. More phage should be isolated and compared genomically to improve our ability to control bacterial populations in wastewater treatment plants and to learn about their potential use as antibacterial treatments in medicine.
1052. Mitochondrial Toxicity of Antimicrobial Agent Cetylpyridinium Chloride
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): John Burnell, Sasha Weller, Brandon Aho, Bright Obeng, Samuel Hess, Julie Gosse
Undergraduate Student Presentation
Faculty Mentor: Julie Gosse
Abstract: People are exposed to high concentrations (up to 3 millimolar) of antibacterial agent cetylpyridinium chloride (CPC) via consumer products and agricultural use despite a lack of knowledge of CPC’s effects on eukaryotes. We found that non-cytotoxic, low-micromolar doses (~1000-fold lower than those used in products) of this positively-charged quaternary ammonium compound inhibit ATP production in rat immune RBL-2H3 mast cells in galactose media, which forces the cells to use their mitochondria for ATP production. CPC potently inhibits ATP production starting at 0.5 µM within a 90-minute exposure. CPC inhibits half of mitochondrial ATP production at 1.5-1.9 µM, a range similar to the 1.2 µM concentration seen for a canonical mitotoxicant CCCP. Mitochondrial [Ca2+] disruptions can lead to mitochondrial deformation and dysfunction. Thus, we tested CPC effects on mitochondrial Ca2+ levels with a fluorescent reporter (CEPIA2mt) and found that CPC lowers mitochondrial [Ca2+] in galactose media. Another potential underlying mechanism is CPC interference with key lipid phosphatidylinositol 4,5-bisphosphate (PIP2). Previous work revealed that multiple PIP2–protein interactions are disrupted by CPC, and other researchers have shown that disruption of PIP2 in the mitochondrial outer membrane leads to mitochondrial fission. Thus, we utilized super-resolution fluorescence photoactivation localization microscopy (FPALM) of Dendra2-TOM20 (outer mitochondrial membrane marker) in live mast cells: CPC causes nanostructural changes to mitochondria including production of “donut” morphology. Overall, this work reveals CPC as a mitochondrial toxicant despite its widespread use, highlighting the importance of further research into its toxicological safety.
1053. Variable Mest Expression in Genetically Identical Mice Contributes to Obesity
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Madeleine Nowak, Rea Anunciado-Koza, Crystal Bilodeau, Edward Jachimowicz, Robert Koza
Graduate Student Presentation
Faculty Mentor: Robert Koza
Abstract: The environment and genome interact through the epigenome. This interaction can lead to variable phenotypes, even when individuals are genetically identical. In an otherwise genetically identical inbred mouse population, raised in carefully controlled environmental conditions, we showed dramatic inter-individual variation in their development of diet-induced obesity. Adipose expression of mesoderm specific transcript (Mest), an imprinted gene only expressed from the paternal allele, is consistently and positively associated with fat mass expansion in mice. Furthermore, levels of Mest expression in adipose tissue biopsies of mice prior to feeding dietary fat can predict future development of obesity. This suggests that the epigenome has a role in the regulation of Mest. Mest is primarily expressed by mature adipocytes, but adipose tissue is heterogeneous with 50-90% of cells being non-adipocytes. To enhance the likelihood for identifying epigenomic features controlling variable Mest expression in adipocytes, we used the NuTrap mouse model developed by Roh et al. (2017) which allows us to isolate mature adipocyte nuclei using a nuclear fluorescent marker tied to adiponectin expression. The overarching goal of this project is to use NuTrap mice to isolate nuclei from mature adipocytes from inguinal and visceral fat tissues to discover the epigenetic source of variable Mest expression. We have optimized nuclei isolation via fluorescence activated cell sorting (FACS) and isolated RNA from adipose tissue to confirm Mest expression levels. We have also begun to identify the optimal methods for sequencing studies to identify differences within the genome associated with variable expression of adipocyte Mest in mice.
1054. Exercise Induced Growth Factor Increases as a Function: Translational Project Among Human and Animal Models of Preclinical Alzheimer’s Disease
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Amanda Wain, Kate Foley, Lindsey Lagerstrom, Jennifer Thompson, Taylor Mcmillan, Fayeza Ahmed
Graduate Student Presentation
Faculty Mentor: Fayeza Ahmed
Abstract: Alzheimer’s disease (AD) is incurable [1], thus research on delaying onset or prevention of AD focuses on modifiable risk factors [2]. There is overwhelming evidence of a vascular contribution to AD [3]. Growth factors that regulate neurogenesis and angiogenesis play an essential role in brain health and homeostasis. The pathological changes in these factors are early predictors of cognitive decline and dementia [4]. Regular exercise increases both peripheral and neuronal growth factors mirroring the protective effects of elevated intrinsic levels, though the degree of benefit is still unclear. This may be due to the age group studied and the limitations of confounding variables inherent in human subjects research. Given AD pathology begins decades before symptom onset [5], studying middle-aged adults may be a critical period for AD prevention. In a new translational project between the Ahmed and Howell labs, we characterized these growth factors (BDNF, VEGF, and an understudied factor, FGF-21) based on exercise level among both mice and humans, including those at genetic risk for AD. Using a mouse model, genetically modified with humanized APOE3/4 (AD genetic risk allele) we investigated the effects of exercise and the ability of this animal model to translate to active or sedentary, midlife community participants. Data analysis is in progress. If the model proves to be translatable, longitudinal intervention studies can be shortened by decades in order to find ways of preventing, delaying or reversing Alzheimer’s disease and vascular dementia. [1] Cummings JL, Morstorf T, Zhong K. Alzheimer’s disease drug-development pipeline: few candidates, frequent failures. Alzheimers Res Ther. 2014 Jul 3;6(4):37. doi: 10.1186/alzrt269. PMID: 25024750; PMCID: PMC4095696. [2] Barnes DE, Yaffe K. The projected effect of risk factor reduction on Alzheimer’s disease prevalence. Lancet Neurol. 2011 Sep;10(9):819-28. doi: 10.1016/S1474-4422(11)70072-2. Epub 2011 Jul 19. PMID: 21775213; PMCID: PMC3647614. [3] Santos CY, Snyder PJ, Wu WC, Zhang M, Echeverria A, Alber J. Pathophysiologic relationship between Alzheimer’s disease, cerebrovascular disease, and cardiovascular risk: A review and synthesis. Alzheimers Dement (Amst). 2017 Feb 9;7:69-87. doi: 10.1016/j.dadm.2017.01.005. PMID: 28275702; PMCID: PMC5328683. [4] Cotman CW, Berchtold NC, Christie LA. Exercise builds brain health: key roles of growth factor cascades and inflammation. Trends Neurosci. 2007 Sep;30(9):464-72. doi: 10.1016/j.tins.2007.06.011. Epub 2007 Aug 31. Erratum in: Trends Neurosci. 2007 Oct;30(10):489. PMID: 17765329. [5] Cotman CW, Berchtold NC, Christie LA. Exercise builds brain health: key roles of growth factor cascades and inflammation. Trends Neurosci. 2007 Sep;30(9):464-72. doi: 10.1016/j.tins.2007.06.011. Epub 2007 Aug 31. Erratum in: Trends Neurosci. 2007 Oct;30(10):489. PMID: 17765329.
1055. Characterization of Four Novel Prophages and Their Polymorphic Toxin Systems in the Pathogenic Mycobacterium salmoniphilum – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Sam Kovacs, Emma Boudreaux, Wyatt Cannell, Eleanor Carrolton , Sophie Childs, Veronica Chuns , Julia Coombs, Abigail Dichiara, Addie Gambol, Oyku Goktug , Amy Hardy, Parker Landsbergen, Hanna Lembree, McHenna Martin , Abi McNally, Dorian Royal , Alexander Russell, Annika Savage, Makayla Sisco, Maple Waltner, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacterium abscessus is a non-tuberculosis pathogenic bacterium that causes soft tissue and pulmonary infections in Cystic Fibrosis patients (CF) that are often completely drug resistant. Previous studies have shown that a significant portion of M. abscessus isolates carry prophages which are predicted to contribute to pathogenicity and antibiotic resistance. To better understand the relationship between prophages and pathogenicity, we sequenced the genome of the fish pathogen, Mycobacterium salmoniphilum (MSKB-2), a close relative of M. abscessus. Using the program Phaster, we identified four novel prophages that share at least 35% gene content with M. abscessus prophages and therefore were assigned to Mab clusters. ProphiMSKB2-2, prophiMSKB2-3 and prophiMSKB2-4 have genome lengths of 61,691bp, 72,955 and 34,502 bp and were assigned to clusters MabE, MabK and MabN, respectively. ProphiMSKB2-1 is distinct from M. abscessus prophages already described, although nearly identical sequences exist in sequenced genomes of clinical M. abscessus isolates in GenBank. We recommend a novel cluster assignment to MabS. ProphiMSKB2-4 has a large deletion in its structural gene region and likely cannot form active phage particles. ProphiMSKB2-1, prophiMSKB2-2, and prophiMSKB2-4 encode polymorphic toxin systems which are predicted to contribute to bacterial virulence. Further analysis of the role these genes play in bacterial virulence and pathogenicity is imperative to the discovery of new and more effective treatments.
1056. Asymmetric Catalysis of Chiral Phosphate Mimics
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Rebecca Collins, Ahmed Numan, Matthew Brichacek
Undergraduate Student Presentation
Faculty Mentor: Matthew Brichacek
Abstract: Over the past decade, antisense oligonucleotides— chiral phosphonates which mimic the phosphodiester backbone of RNA— have been evaluated as therapeutics to target mRNA and block diseases causing deficient protein expression. However, the stereochemical arrangement of the chiral phosphonates has an effect on their biological activity. Currently, in the synthesis of antisense oligonucleotides, the stereochemistry of the phosphorus is not controlled. Chiral nucleophilic catalysts can be employed to produce the biologically active product with a high enantiomeric excess (ee). Previous work by the Brichacek group identified the catalyst benzotetramisole (BTM), which possesses these enantioselective capabilities and provides a modest yield of the active enantiomer (~43% average ee). In this study, the synthesis of a novel asymmetric catalyst, hyperbenzotetramisole (hyperBTM) was pursued. BTM and hyperBTM will each be screened in a chiral phosphonate synthesis to determine their respective selectivities.
1057. Novel Method of Measuring Bone Density Using Audible Sound
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Evan Bess, Justin Williford, Michael Mason
Undergraduate Student Presentation
Faculty Mentor: Michael Mason
Abstract: Osteoporosis is a medical condition where there is a progressive degradation of bone tissue which correlates with a characteristic decrease in bone mineral density (BMD). Populations most at risk for developing osteoporosis include post-menopausal women, diabetic patients, and the elderly, which represent a large population within the state of Maine. Current methods of assessing BMD are expensive and can expose patients to small doses of ionizing radiation. The purpose of this work is to develop a device that can be used as a rapid, low-cost, noninvasive diagnostic tool to measure calcaneal bone density using audible sound. To do this, a LabVIEW 2019 software package was developed, and two physical devices were constructed. The two prototypes contained three primary components, a single speaker and two microphones positioned 90⁰ and 180⁰ from the speaker. The components used in each device was validated through power spectrum analysis with a focus on power transmission through air. Preliminary results show an ability of the components to distinguish different levels of power being transmitted through air at different thicknesses.Acknowledgements: The authors thank Professor Michael Mason, Dr. Todd O’Brien, Forrest Flagg, and Dr. Robert Bowie for their critical advice and support during this project.
1058. Skin Formation of Crosslinked TEMPO Cellulose Nanofiber Hydrogel
Submission Type: Exhibit
Submission Category: Biomedical Sciences
Author(s): Jacob Holbrook, Kora Kukk, Michael Mason
Undergraduate Student Presentation
Faculty Mentor: Michael Mason
Abstract: Due to the high risk of viral, bacterial, fungal, and parasitic disease being present in aquaculture production, it is necessary to develop a new method of vaccination that is not only economical but also effective in long term prevention of disease. A potential method for economical and effective aquaculture is through the production of an antigen encapsulated in a crosslinked TEMPO cellulose hydrogel. These hydrogels are produced by dropping 1.7% weight TEMPO cellulose nanofibers (CNF) into a citric acid solution that is left to physically cross-link over a 24 hour time period before being washed for an additional six days. After the completion of the wash steps, the hydrogel is dried in preparation for delivery into the fish. The aim of this study is to determine how the hydrogel behaves as it is being dried. In order to accomplish this goal, the TEMPO CNF will be complexed with a cationic dye which will be attracted to the negatively charged TEMPO CNF matrix. The cationic dyed hydrogels will be analyzed as they dehydrate to show the possible presence of skin formation. A custom built imaging device will be used to visualize the localization of the indicator dyes as a function of time as the hydrogel dehydrates. This imaging device consists of an optical camera and single lens to image the cross section of the hydrogel at multiple dehydration stages. Recent findings and engineered imaging setup will be presented.
1059. Time-lapse Imaging Reveals That Muscle Precursor Position is a Key Determinant of Fin Muscle Fate in Zebrafish
Submission Type: Exhibit
Submission Category: Biomedical Sciences
Author(s): Carolina Cora, Jared Talbot
Graduate Student Presentation
Faculty Mentor: Jared Talbot
Abstract: Limb muscle formation is a result of a multistep process in vertebrate embryonic development. First, muscle-forming cells generate segments along the anterior-posterior body axis called somites. Next, migratory muscle precursors (MMPs) detach from the ventral portion of somites and move distally to give rise to hypaxial skeletal muscles. In zebrafish embryos, fin muscle is formed by the middle fork of three cell streams emanating from somites 1 through 6. To better understand how fin muscle arises, we conducted high-resolution time-lapse imaging using a newly updated confocal microscope. We imaged a transgenic fish line that expresses green fluorescent protein in the membrane of muscle precursors and mature muscle cells, allowing us to follow MMP migration and differentiation. Then, with a machine-learning driven program, we identified multiple cell centers and tracked the movement of individual MMPs in three dimensions. The tracking was challenging, due to the difficulty of automating recognition of numerous cell-centers through different planes and correctly connecting these cells between multiple timepoints. Nonetheless, we were able to create a trajectory for the MMPs over many hours of development. By examining tracks through this time-period, our analysis brought new clarity to the origins of fin muscle, suggesting that the fin develops from cells that arise from the 4th somite specifically, and that original MMP position is a strong determinant of future muscle outcome.
1060. ColorFlu Zebrafish: An In Vivo Fluorescent Influenza A Virus Infection Model
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Brandy-Lee A. Soos, Benjamin King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Influenza virus infection can cause severe respiratory disease and is estimated to cause 9-41 million illnesses annually in the US. The long-term goal of our research is to understand how the innate immune system responds to influenza virus infection to inform the development of new therapies. Zebrafish embryos are powerful models to study innate immunity in response to influenza A virus (IAV) infection since adaptive immunity is not fully functional until several weeks after development. While the function of immune cells can be studied in vivo using fluorescent reporter lines, a significant limitation is the ability to visualize the virus. To overcome this limitation, we developed new methods to study IAV infection in zebrafish by using four different fluorescent IAV strains, called ColorFlu. Using our ColorFlu zebrafish infection model, we can monitor IAV infections and the subsequent innate immune response in real-time. We have used this model to study how neutrophils, generate and release reactive oxygen species (ROS) while responding to infection. .ROS can degrade pathogens directly through oxidative damage. However, dysregulation of ROS can lead to tissue damage and death due to hyperinflammation. We hypothesize that regulation of neutrophil ROS production is mediated by gene networks composed of both coding and noncoding genes. To investigate our hypothesis, we have been studying how inhibitors of ROS alter survival, viral burden, and neutrophil migration using ColorFlu. The ColorFlu zebrafish model of IAV infection is a powerful new tool to visualize the impact of genetic and drug therapeutic interventions on IAV infections.
1061. Toxin/Antitoxin Systems in Prophage Genomes Could Increase Virulence in the Host, Group B Streptococcus.
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Kaitlyn Jodoin, Caitlin Wiafe-Kwakye, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Group B Streptococcus (GBS) is the leading cause of neonatal meningitis. Found most commonly in the female reproductive tract, GBS is an opportunistic pathogen that disproportionately infects neonates during pregnancy or soon after birth. Bacteriophage (phage) are bacterial viruses and are the most numerous entity on earth. Phage have the ability to integrate their phage genome into the bacterial host genome, becoming a prophage. Once integrated, the prophage genes are able to be expressed by the bacteria. Multiple other strains of bacteria have prophages that promote increased bacterial fitness and virulence. However, not much is known about the prophages that are found in GBS. Therefore, the aim of this study is to determine how prophages might contribute to virulence in GBS. A total of 49 GBS clinical isolates were collected from the vaginal tracts of pregnant females and a total of 43 prophages were identified. phiDMC20 is a prophage isolated from GBS strain DMC20, which is a serotype V, clonal complex 19 bacteria. The bacterial genome was sequenced and the prophage genome extracted and annotated. phiDMC20 has a genome length of 36680 base pairs with 55 putative genes. phiDMC20 is significant due to the presence of a HicA/HicB toxin/antitoxin system. The presence of these toxin/antitoxin systems likely provide significant advantages to the host bacterium by increasing virulence. Future research includes continuing to annotate the 26 other prophages extracted from GBS clinical isolates and also investigate the effect these toxin/antitoxin systems have on virulence.
1062. Deciphering the Signaling Mechanisms of JC Polyomavirus
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Remi Geohegan, Michael Wilczek, Lauren Cusson, Sophie Craig, Melissa Maginnis
Undergraduate Student Presentation
Faculty Mentor: Melissa Maginnis
Abstract: JC polyomavirus (JCPyV) causes a persistent, asymptomatic infection of the kidneys in up to 80% of the population. In immunocompromised individuals the virus reactivates, traffics to the brain, and infects astrocytes and oligodendrocytes. The gradual loss of these cells results in progressive multifocal leukoencephalopathy (PML), characterized by cognitive dysfunction, motor impairment, and death. There is no current cure for PML. To develop successful treatments, it is critical to better understand how the virus takes over host-cell signaling pathways for successful infection to identify potential targets. JCPyV activates extracellular signal-regulated kinases (ERKs) within the mitogen activated protein kinase (MAPK) pathway, a cell signaling pathway commonly exploited by viruses for its role in cellular differentiation, proliferation, and death. ERK becomes activated as early as fifteen minutes post infection, and treatment of cells with ERK inhibitors reduces JCPyV infection, while treatment of cells with a chemical ERK activator, PMA, increases JCPyV infection. The mechanism by which ERK becomes activated during infection, is not fully defined, yet upstream signaling proteins of the MAPK pathway could play an important role in signal activation and viral infection. SRC, a protein tyrosine kinase and upstream signaling molecule of the MAPK pathway, was targeted for knockdown, and JCPyV infection was measured. Taken together, this research provides a better understanding of cellular signaling events during JCPyV infection and will improve the possibility of finding targets for novel antiviral treatments for PML.
1063. Defining the Role of Src Kinase in Activation of the MAPK/ERK Signaling Pathway During JCPyV Infection
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Lauren Cusson, Remi Geohegan, Sophie Craig, Melissa Maginnis
Undergraduate Student Presentation
Faculty Mentor: Melissa Maginnis
Abstract: JC polyomavirus (JCPyV) infection is established in approximately 50-80% of the adult population, as a persistent asymptomatic infection of the kidneys. In immunocompromised individuals, the virus can spread to the CNS, cause a lytic infection, and progress into the fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). There are currently no approved treatments for PML, and thus it is critical to better define viral infection of host cells to identify potential treatments. Successful JCPyV infection relies on the manipulation of the mitogen activated protein kinase pathway (MAPK), which is responsible for relaying extracellular mitogenic signals into the cell to allow for the proper cellular response. The specific activation of the MAPK pathway upon JCPyV infection has yet to be fully understood. To define how the MAPK pathway becomes hijacked by JCPyV, the goal of this project is to determine whether Src, a tyrosine kinase known to activate the MAPK pathway, is required for activation of MAPK/ERK during JCPyV infection. Cells treated with inhibitors of Src, to limit ERK activation, will be analyzed for JCPyV infection. Taken together, this research will help to better define virus-induced cell signaling mechanisms that lead to viral infection and identify potential targets for PML treatment.
1064. Tailoring Personalized Medicine to Treat Diseases Caused by Genetic Mutations
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): George Horvat, Katelyn Amero, Lindsey Stover, Alison Kueck, Denry Sato, Bruce Stanton, Benjamin L. King
Undergraduate Student Presentation
Faculty Mentor: Benjamin L. King
Abstract: Personalized medicine can predict responses to treatments according to a donor’s genotype in diseases like cystic fibrosis. Cystic fibrosis is caused by various mutations in the CFTR gene which encodes a chloride ion channel protein. The ΔF508 mutation in exon 11 is the most common cause of the disease, and the M470V polymorphism can worsen symptoms. Mutations in exon 4 and 5 of the CYP2C19 gene, which codes for an oxidative enzyme, can predict issues with treatments like the anticoagulant plavix. In this study, anonymous volunteers were screened for the presence of mutations in the CFTR and CYP2C19 genes. Genomic DNA was extracted from sputum samples. The desired exons were amplified using PCR and sequenced for screening. The CYP2C19 PCR products were further subjected to a restriction enzyme assay that was analyzed using gel electrophoresis. Analysis of donor samples A-L showed that all were wild-type for the ΔF508 mutation on the CFTR gene, meaning it does not cause cystic fibrosis. The donors were either heterozygous or homozygous for the M470V mutation, which does not cause the disease but would have the potential to worsen symptoms if the donor had cystic fibrosis caused by another mutation. For CYP2C19, all donors were either wild-type or heterozygous for the polymorphisms on both exons. Therefore each donor has at least one wild-type allele that produces a functioning enzyme which activates Plavix. For donors who are heterozygous on one or both exons, Plavix may be less effective due to the mutated alleles.
1065. The Regulation of Autophagy During The Yeast Pheromone Response
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Mustafa Elhefnawi, Cory Johnson, Joshua Kelley
Undergraduate Student Presentation
Faculty Mentor: Joshua Kelley
Abstract: G-Protein coupled receptors (GPCRs) are essential regulators for many cellular processes and are the largest family of proteins targeted by 35% of FDA approved drugs. Yeast use a GPCR signaling pathway to mate that results in elongation or “shmoo” formation. Endocytosis is a major mode of GPCR regulation, during pheromone response, where the cell internalizes the pheromone receptor. In this process the cell engulfs activated receptors for degradation. The degradative process of these receptors is known as autophagy. Cells use endocytosis and autophagy of activated receptors to downregulate and desensitize pheromone response. We proposed that when yeast respond to pheromone, autophagy the homeostatic degradative process is initiated. Our aim was to determine the molecular mechanisms that link receptor endocytosis to autophagy via an epsin-mediated pathway during the yeast pheromone response. More specifically, we hypothesized that epsins, the endocytic adaptor proteins that facilitate the formation of endocytic pits and are integral to receptor endocytosis, differentially affect downstream autophagic mechanisms. To investigate yeast autophagy, we investigated the differential roles epsins serve in pheromone-induced autophagy. Through live-cell imaging, we found that deletion of Ent1 results in the formation of fewer autophagic bodies in comparison to either wild type cells, or those lacking Ent2. Ultimately, we identified that one of the epsin proteins (Ent1) plays a major role in the regulation of autophagy during cellular stress.
1066. Exploring Proteomic Signatures of Lean Perivascular Adipose Tissue Induced by Methionine Restricted Diet
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Marissa McGilvrey, Bethany Fortier, Calvin Vary, Robert A Koza, Lucy Liaw
Graduate Student Presentation
Faculty Mentor: Lucy Liaw
Abstract: Perivascular adipose tissue (PVAT) surrounds blood vessels and regulates vascular tone. During obesity, inflammation and increased lipid storage in PVAT alter its signaling. In humans, the amount of PVAT increases with obesity and positively correlates with coronary artery disease. Methionine-restricted (MR) diets extend lifespan, improve glucose metabolism, and decrease adiposity despite diet-induced obesity in rodents. Positive effects of MR on white adipose tissue have been attributed to increased energy expenditure and browning. However, MR has only been investigated over long-time courses, and effects on PVAT are unknown. To identify initiating signals from PVAT that correspond to phenotypic conversion, we fed male C57BL/6 mice with a high fat diet (60 kcal% fat, 0.86% methionine) until they were obese. Weight matched mice were then either maintained on this diet or switched to a high fat/methionine restricted diet (60 kcal% fat, 0.12% methionine). Mice on this MR diet lost weight and had significantly reduced lipid in PVAT as early as 3 days after initiation. We performed proteomics with PVAT collected after 3, 5, or 10 days of MR analyzed tissues by mass spectrometry to identify proteomic signatures. When compared to control, PVAT from MR conditions exhibited significant differences (p<0.05) in with 705, 437, and 581 proteins on days 3, 5, and 10, respectively. Gene Ontology Enrichment Analysis revealed biological processes related to “spliceosome”, “fatty acid metabolism”, “AMPK signaling”, “collagen fibril organization”, and “regulation of heart rate”. These results suggest PVAT metabolic reprogramming occurs early in MR and may explain long term benefits.
1067. Cardiac Risk and Cognition in Middle Aged Adults
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Jaclyn Hazlewood, Sarrah Marcotte, Jennifer Thompson, Fayeza Ahmed
Undergraduate Student Presentation
Faculty Mentor: Fayeza Ahmed
Abstract: Abstract: Alzheimer’s disease (AD) is considered a disease that begins in older adulthood; however, the pathological processes at fault begin decades earlier[1] , indicating research should include middle-aged samples. Researchers are now looking at how individuals’ lifestyle choices may aid or prevent this precursory decline in their cognition i.e. “modifiable risk factors”. Given the known association between vascular function and AD (CITE), we aimed to investigate the association between The Framingham Risk Score (FRS) is a calculation of one’s risk for developing cardiovascular disease (CVD) by measuring their risk factors of sex, cholesterol levels, blood pressure, diabetes diagnosis, and smoking history [3]. This current study aims to compare the cognitive abilities of a middle-aged population to their cardiovascular risk score using linear regression models. Several domains of cognition were obtained, including attention, learning/memory, processing speed, language, and executive functions. Additionally, APOE risk genes were collected for a subset of this sample. Finding a more explicit correlation between brain health and cardiovascular health in middle ages will help determine preventative strategies, like exercise, to mitigate AD risk. These pathological links will also allow for a better understanding of the early development of AD in asymptomatic middle aged adults. Data collection and analyses are currently in progress. Acknowledgements: This project is part of a larger study in the faculty mentor’s lab. References: [1] Joosten, H., van Eersel, M. E. A., Gansevoort, R. T., Bilo, H. J. G., Slaets, J. P. J., & Izaks, G. J. (2013). Cardiovascular risk profile and cognitive function in young, middle-aged, and elderly subjects. Stroke, 44(6), 1543–1549. https://doi.org/10.1161/strokeaha.111.000496 [2] Tolppanen, A.-M., Solomon, A., Soininen, H., & Kivipelto, M. (2012). Midlife vascular risk factors and Alzheimer’s disease: Evidence from epidemiological studies. Journal of Alzheimer’s Disease, 32(3), 531–540. https://doi.org/10.3233/jad-2012-120802 [3] Cardiovascular Disease (10-year risk). Framingham Heart Study. (n.d.). Retrieved March 4, 2022, from https://biolincc.nhlbi.nih.gov/media/teachingstudies/FHS_Teaching_Longitudinal_Data_Documentation_2021a.pdf?link_time=2022-03-04_03:57:48.866619
1068. Sentinel Spectroscopy: Light-Surface Interactions for the Continuous Detection of Chemical Composition in Space Agriculture Runoff
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Christopher Erb, Liza White, RJ Perry, Caitlin Howell
Undergraduate Student Presentation
Faculty Mentor: Caitlin Howell
Abstract: The success of long-haul space travel and semi-permanent bases on Earth’s moon and on Mars will heavily rely on optimized agricultural practices and agricultural analytics. Monitoring the health of space-grown crops in real-time, through the detection of chemical contaminants in plant effluent, will prove critical to efficiently supplying astronauts with sustainable food options. Our lab is developing a low-cost, automated detection system to analyze runoff from space-based agriculture using a mass-produced, nanopatterned material from Maine’s paper industry. This system will make use of the fact that the way in which light interacts with the nanopatterned material changes as the light passes through effluent containing different chemical compounds and biomolecules. Reliable and effective low-cost water monitoring systems are vital to humankind’s effort at establishing permanent extraterrestrial colonies.
1069. A Model to Study the Direct Effects of β2-Adrenergic Receptor on Osteoclasts
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Rebecca Peters, Audrie Langlais, Ryan Neilson, Katherine Motyl
Graduate Student Presentation
Faculty Mentor: Katherine Motyl
Abstract: The sympathetic nervous system (SNS) contributes to bone homeostasis through beta adrenergic (βAR) signaling. The SNS signals to the osteoblast, which secretes RANKL to bind the RANK receptor on osteoclasts and stimulate bone resorption. However, we hypothesize that direct βAR signaling to the osteoclast may also occur because when mice were treated with a β-blocker, bone resorption was reduced without changing RANKL. Osteoclasts express β1AR and β2AR, but β2AR is more highly expressed in bone. To determine the effects of β2AR on osteoclast differentiation and resorption, we crossed Adrb2fl/fl mice with the myeloid lineage specific Lyz2Cre/Cre mice to generate an osteoclast progenitor knockout of Adrb2. To test deletion of Adrb2 within the osteoclast, we measured gene expression of Adrb2 in the bone marrow and found comparable levels of deletion in Cre/Cre and Cre/+ mice. We also found reduced levels of Adrb2 in Cre/+ mice as compared to +/+ in osteoclasts from femur sections using RNAScope™. Additionally, we measured areal bone mineral density and bone microarchitecture at 8 weeks of age and found no significant changes among femur bone parameters in either sex. This is consistent with the finding that bone is not affected in Adrb2 global knockout mice until six months of age. At this point, we have validated the Adrb2fl/flLyz2Cre/+ mouse model to study the direct role of β2AR on osteoclasts. Future work will use this model to study differences in osteoclast differentiation and resorption with the loss of β2AR using aging and pharmacological models to stimulate SNS activity.
1070. Mycobacterium chelonae Prophage ProphiMSKB1-4: Armed and Prepared to Translate
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Abigail McNally, Sally Molloy
Undergraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Mycobacterium abscessus causes skin and pulmonary infections in those who are immunocompromised or have cystic fibrosis. These infections are extremely hard to treat because they are almost entirely resistant to antibiotics. Most strains of M. abscessus, and other related pathogenic mycobacteria such as M. chelonae contain prophage, or integrated viral genomes, that may increase host pathogenicity. To learn more about the prophages of pathogenic mycobacteria we sequenced the genome of an M. chelonae strain, MCKB1, isolated from a diseased fish. Using the program Phaster we identified four novel prophages that shared high gene content with the prophages of M. abscessus. Based on shared gene content, each of the prophages were assigned to M. abscessus clusters: prophiMCKB1-1, cluster MabF; prophiMCKB1-2, cluster MabN; prophiMCKB1-3, cluster MabK; and prophiMCKB1-4, cluster MabI. ProphiMCKB1-4 is found on contig 7, has a genome length of 76,080 base pairs, encodes 137 genes, and 24 tRNAs. One unique feature of prophiMCKB1-4 is the polymorphic toxin system adjacent to the left attachment site, which is predicted to contribute to mycobacterial virulence. In future research we will complete the genome annotation and further characterize the polymorphic toxin systems and its potential role in mycobacterial virulence and antibiotic resistance.
1071.The Effects of Antifungals on Candida albicans growth in the presence of Group B Streptococcus
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Anna Lane, Kathryn Patenaude, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Streptococcus agalactiae (GBS) and Candida albicans (Ca) are opportunistic commensal microorganisms that colonize the vaginal tract of some individuals. While GBS typically exists commensally within its host, it can be passed to neonates during vaginal birth and cause life-threatening infection. Ca is an opportunistic pathogen that commonly causes vulvovaginal candidiasis and can cause infections of the bloodstream and internal organs in vulnerable patients. Some GBS strains are known to physically interact with Ca in its hyphal, filamentous form, and there is evidence of synergistic interactions between GBS and Ca in colonization of the vaginal tract. In this study, the effect of co-culture of GBS and Ca on the efficacy of the antifungal fluconazole was investigated. When GBS was added to a co-culture of Ca that was treated with fluconazole in a nutrient-rich environment, there was a ~4.8 fold decrease in Ca growth compared to an individual culture of Ca with the same treatment. This effect was not observed in a nutrient-poor environment. These results demonstrated that the presence of GBS can have a positive impact on the efficacy of antifungal treatments of Ca. Conversely, presence of Ca increased GBS growth in a nutrient-poor environment, with a ~4.2 fold increase in GBS growth with Ca present compared to GBS cultured alone. As GBS and Ca both colonize the vaginal tract, the effect of antifungals on Ca growth in the presence of GBS and synergistic associations between GBS and Ca have important implications for the effective treatment of disease involving these pathogens.
1072. Abstract Withdrawn
1073. Reusable Cloud-Based Bioinformatics Analysis Environments to Enhance Data Science
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Steven Allers, Benjamin King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Widespread application of high-throughput DNA sequencing in biomedical research generates increasingly large datasets that require substantial computational resources to store the data and run bioinformatics analysis workflows. A major obstacle for many researchers is having access to bioinformatics analysis environments that are tailored to their research. Cloud-based computing and data storage resources provide one potential solution as individual researchers can build and run their own resources with lower cost of maintenance and rapidly scale the resources based on needs. We have created a reusable cloud-based bioinformatics analysis environment for a RNA sequencing analysis workflow, and provide reusable training material on how to use this workflow. The workflow consists of retrieving FASTQ files, read diagnostic analysis and trimming, aligning reads, and generating read counts per gene. The analysis workflow was implemented using SnakeMake where steps are run sequentially based on a set of rules. We have also made a tutorial on using the R/DESeq2 package to analyze the read counts and generate a list of differentially expressed genes. The workflow and training materials are designed to complement bioinformatics training courses offered by the Maine INBRE program where course participants have difficulty recreating the computing environment needed to run those workflows once they return to their home institutions. This proposal addresses these difficulties by providing resources and training to create cloud-based computing environments for biomedical research that uses bioinformatics tools. Our project may serve as a model to successfully broaden the application of bioinformatics among INBRE and other IDeA programs nationwide.
1074. Low Dose Arsenic Exposure and miR-199 Dysregulation Alters the Innate Immune Response to Pseudomonas aeruginosa Infection in Zebrafish.
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Liz Saavedra, Brandy Soos, Carol Kim, Benjamin L. King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: The innate immune system functions to prevent infection and respond to injury. Innate immune function can be altered by perturbing gene function and through exposure to environmental toxicants, such as low-dose arsenic. Decreased innate immune function reduces the capacity to combat opportunistic pathogens, such as Pseudomonas aeruginosa (PA14). However, these mechanisms are poorly understood. MicroRNAs (miRNAs) are regulatory RNAs with demonstrated roles in immune function. The zebrafish can be used to investigate how arsenic and miRNA dysregulation disrupts the innate immune response to PA14 infection. Low-dose arsenic exposure was shown to inhibit the immune response in zebrafish. A prior study of PA14 infection in zebrafish demonstrated that miR-199 regulated neutrophil migration. We hypothesize that low-dose arsenic exposure disrupts the regulation of miR-199 and other miRNAs during PA14 infection. We profiled miRNA expression in 48 hours post-fertilization embryos infected with and without PA14 at 6 and 18 hours post-infection (hpi) following exposure to 0, 2, and 10 ppb arsenic. The largest number of differentially expressed microRNAs in response to infection at 6 and 18 hpi were in embryos exposed to 2 ppb arsenic with 81 and 87 microRNAs, respectively. MiR-199 was upregulated in response to infection at 6 hpi but downregulated at 18 hpi. Using Tg(lyzC:miR-199-3-Dendra2)pu19 zebrafish, neutrophil-specific miR-199 overexpression improved survival during systemic PA14 infection in embryos exposed to 2 ppb and 10 ppb arsenic. Ongoing survival and bacterial burden assays and confocal imaging will provide new insight into innate immunity and the toxicological effects of arsenic.
1075. Alkaline Phosphatase Deficiency Leads to Decreases in Adipogenesis and Mitochondrial Function
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Victoria DeMambro, Samantha Costa, Jennifer Daruzska, Clifford Rosen, Anyonya Guntur
Graduate Student Presentation
Faculty Mentor: Anyonya Guntur
Abstract: Hypophosphatasia (HPP) is caused by loss of function mutations in the tissue-nonspecific alkaline phosphatase (TNAP) gene (Alpl) which results in rickets, osteomalacia, bone fragility and lean body mass in severe childhood forms [1]. In vitro, human TNAP positive stromal vascular fraction (SVF) cells have higher adipogenesis and mitochondrial respiration, while inhibition of TNAP decreases lipid accumulation [2-4]. To further delineate the role of TNAP in adipogenesis and mitochondrial function our lab is utilizing a global AlplKO model. AlplKO and control pups were collected at postnatal D9, weighed and inguinal white adipose tissue (IWAT) depots collected for histology as well as in vitro analysis of adipogenesis and mitochondrial function utilizing the XF96 Seahorse analyzer. AlplKO pups weighed less than controls at D9 (p< 0.0001). Isolated AlplKO IWAT depots weighed less (p< 0.0001) and exhibited smaller adipocyte size vs. controls (p= 0.01). In vitro, IWAT-SVF cells from our AlplKO mice exhibited reduced oil red staining at D8 of adipogenic differentiation (p< 0.0001) despite similar crystal violet staining coupled with downregulation of several key adipogenic genes including Pparg (p< 0.0001) and Cebpa (p< 0.0001). Seahorse analysis at D0 and D8 of differentiation revealed significantly lower mitochondrial respiration (D0, D9: p< 0.0001) and ATP production rates (D0: p=0.005; D9: p= 0.0006) suggesting defects in mitochondrial function in cells lacking TNAP. Studies are ongoing to test our hypothesis that the lack of TNAP in adipocyte progenitor cells leads to a decrease in adipogenic differentiation and lipid accumulation due to defects in mitochondrial dynamics and function.
1076. Altered Patient Metabolomic and Inflammatory Transcriptomics After Fasting and High Calorie Diet in Bone Marrow Adipocytes
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Samantha Costa, Gisela Pachón-Peña, Julie Dragon, Scott Tighe, Calvin Vary, Heather Campbell, Clifford Rosen
Graduate Student Presentation
Faculty Mentor: Clifford Rosen
Abstract: The development of bone marrow adipose tissue (BMAT) is a normal physiological process and arguably of importance in regulating energy expenditure and metabolism. However, extensive BMAT accumulation that occurs in obesity and calorie restriction/anorexia, suggests aberrant BMAT formation has pathological implications. The present study aims to assess the dynamics of bone marrow (BM) metabolism in response to a 10-day high calorie diet (HCD) followed by a 10-day fasting protocol. BM adipocytes (BMAds) and BM sera were collected at baseline and on the final day of each diet protocol, respectively. Comprehensive and integrated analyses were used; RNA-sequencing, proteomics, and lipidomics. RNA-sequencing of HCD BMAd differentially expressed genes (DEGs) showed an upregulation of FOXP3, the transcription factor that controls the development of regulatory T-cells. In comparison, fasting BMAd DEGs showed an upregulation of CFD (Adipsin) and CFH, which are part of the alternative pathway. Proteomic analysis of HCD BM sera showed a significant (p<0.05) upregulation of ZA2G, which stimulates lipid degradation. While fasting BM sera revealed significantly downregulated proteins pertaining to B-cell production/regulation. To investigate the underlying mechanism for adipogenesis, we performed lipidomic analyses of BM sera. The results showed lipid droplet biogenesis/storage was downregulated after HCD (p=0.00325; FDR=0.0109) but upregulated after fasting (p=0.00550; FDR= 0.0170). Overall, our findings demonstrate key differences in inflammatory response and lipid metabolism between HCD and fasting. These data support the concept that nutrient flux is an important determinant of BMAT. Further analyses are needed to understand the effects of nutrition on BM adipogenesis and immune response.
1077. Role of Non-Coding RNAs in Adaptation to Environmental Stressors Through the Study of Natural Populations
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Kayla Barton, Adrienne Kovach, Brian Olsen, Benjamin King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: The long-term goal of our research is to understand the genomic architecture of adaptation to environmental stressors. The ability to maintain cellular homeostasis under a spectrum of stressors is critical to survival. Tidal marsh sparrow species have adapted to live in a harsh environment relative to inland species. We are studying multiple sparrow species in tidal marsh, generalist, and inland environments to determine which genes and pathways are under selection in tidal marsh populations using comparative genomics, population genomics, and transcriptomics. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression of target genes. The number of miRNAs in animals is proportional to increasing organismal complexity. As such, they can be used as characters to study evolution. Prior studies have examined the differences in miRNAs between broad ranges of taxa. We aim to determine whether the sets of miRNAs differ among a group of closely related species, allowing us to better understand the contemporary evolution of these species. 87 sparrow chicks were opportunistically sampled across six coastal Maine and New Hampshire field sites. We developed a protocol for extracting RNA from chicks, extracted RNA, and small RNA sequencing is currently underway for 12 samples from Nelson’s, Saltmarsh, Savannah, and hybrid Nelson’s/Saltmarsh species. In addition we are building a genomic analysis pipeline to build a Genotyping-in-Thousands by sequencing (GT-seq) panel that will be used to study sequence variation among miRNA and other loci. To our knowledge, our study is the first to examine the evolution of miRNAs among these species.
1078. GPCR-directed Septin Structures Are Mediated by Cdc42 GAPs and Epsins – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Cory Johnson, Andrew Hart, Sarah G. Latario, Joshua B. Kelley
Graduate Student Presentation
Faculty Mentor: Joshua B. Kelley
Abstract: Yeast mating utilizes a GPCR signaling pathway to initiate a MAPK cascade and Cdc42-mediated polarization of the actin cytoskeleton to facilitate the growth of a mating projection, or “Shmoo.” Proper receptor-induced morphogenesis includes septin structure formation at the base of the mating projection, peripheral to the leading edge. Septin localization is disrupted when pathway desensitization by the RGS is defective. The GPCR-driven signaling mechanisms that direct septins to organize proximal to the leading edge and that tie this to Gα desensitization are not understood. Septin deposition is known to be controlled by Cdc42 GAP activity. Therefore, we deleted each of the three Cdc42 GAPs in yeast expressing a hyperactive Gα mutant. We found that deletion of either BEM3 or RGA2 rescued septin distribution. Additionally, Cdc42 GAPs are thought to help release septin from the Cdc42 effector proteins Gic1 and Gic2. We next examined if either Gic contributed to Gα-directed septin organization and found that cells lacking GIC1 rescued septin distribution. The endocytic adapter proteins called epsins are known to both bind Cdc42 GAPs and influence septin organization. We therefore deleted either ENT1 or ENT2 and evaluated septin distribution. We found that deletion of either epsin rescued septin organization. Given epsins’ role in endocytosis, we conclude that pheromone-induced septin distribution peripheral to the mating projection is likely controlled through endocytic cargoes recruiting epsins. Since these deletions are expected to slow septin structure formation, we propose that hyperactive Gα increases endocytic rate of one or multiple cargoes, leading to septin misplacement.
1079. Defining the Role of RAB27a in Vascular Contractility
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Ashley Soucy, Anne Harrington, Larisa Ryzhova, Benjamin Tero, Abby Kaija, Lucy Liaw
Graduate Student Presentation
Faculty Mentor: Lucy Liaw
Abstract: RAB27a, a member of the Ras-related protein family, is a trafficking protein that regulates exosome formation and secretion. Dysregulation of exosome secretion has been linked to various diseases including type II diabetes and atherosclerosis. However, the importance of RAB27a in regulating exosome-mediated communication within the vascular microenvironment has yet to be determined. We have established that RAB27a is endogenously expressed in three major cell types that comprise the vascular microenvironment: adipocytes, vascular smooth muscle cells, and endothelial cells. These adipocytes constitute the specialized adipose depot known as the perivascular adipose tissue (PVAT). It is known that PVAT increases the secretion of inflammatory and contractile factors during obesity, which can be detrimental to vascular function. Interestingly we found RAB27a levels increased in PVAT of mice with diet-induced obesity, suggesting the protein might contribute to secretory changes that increase vasoconstriction. Therefore, we hypothesize that loss of RAB27a will reduce vascular contractility during diet-induced obesity. To test our hypothesis, we created a novel Rab27a global knockout (null) mouse on a C57BL6/J background. Characterization of this strain showed no changes in development compared to wildtype mice. Additionally, lipid accumulation and thoracic aorta area were quantified to evaluate for physiological changes. Proteomic analysis of PVAT and thoracic aorta suggest changes in contractility capabilities in the null mice with aging. Results were confirmed through wire myography methods. With this study, we show that RAB27a is important for vascular function and deserves further investigation to understand the impact of PVAT-specific loss on vascular health.
1080. An Overview of Three Biomedical Science Projects across Three Research Institutes
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Lola Holcomb, Jim Coffman, Ben Harrison, Kerry Tucker, Sue Ishaq
Graduate Student Presentation
Faculty Mentor: Jim Coffman, Ben Harrison and Kerry Tucker, Sue Ishaq
Abstract: As a first-year PhD student in the Graduate School of Biomedical Science and Engineering, I have been tasked with completing three different laboratory rotations over this first year of study. As such, this presentation will not focus on one major project, but three unique 10-week-long projects. The first of which, completed under guidance from Dr. Jim Coffman of MDIBL, was a pilot study that investigated behavioral responses of zebrafish larvae in response to light, a stress stimulus. The second project, done under guidance from Dr. Benjamin Harrison and Dr. Kerry Tucker of UNE, used bioinformatics tools to assess whether genes involved with primary cilia, Hedgehog signaling, and/or Gli2 transcription contribute to differential expression and neuropathic pain in naive and Paciltaxel-treated mice. The third and final project, which is currently in progress, will be completed in Dr. Sue Ishaq’s lab. This project will use bioinformatics tools to analyze large datasets in attempt to better understand differences in microbial ecology as a representation of social and environmental inequities.
1081. The TAp63-dependent and -independent DNA Damage Response in Meiotically Arrested Oocytes
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Monique Mills, Chihiro Emori, Zachary Boucher, Ewelina Bolcun-Filas
Graduate Student Presentation
Faculty Mentor: Ewelina Bolcun-Filas
Abstract: Advancements in cancer treatments have improved patient survival rates; however, the genotoxicity of these lifesaving treatments can leave female cancer patients and survivors facing adverse reproductive health problems. Ionizing radiation (IR) is commonly used for cancer treatment. IR induces DNA double-strand breaks (DSBs) and reactive oxygen species (ROS) preferentially killing cancer cells but can kill healthy cells. In somatic cells, DSBs activate the DNA damage response (DDR) pathway, leading to CHEK2-dependent activation of TRP53. Active TRP53 induces senescence, cell cycle arrest, or apoptosis. In oocytes, CHEK2 phosphorylates and activates TA isoform of TRP63 (TAp63). TAp63 is exclusively expressed in oocytes in the ovary and its activation by even low levels of DSBs induces apoptosis before DNA repair occurs. At low-dose radiation, wildtype female mice are depleted of primordial follicles and become infertile, while TAp63-deficient females remain fertile. This suggests that TAp63 plays a major role in oocyte apoptosis after DNA damage. However, at high-dose radiation the majority of TAp63-deficient oocytes are eliminated. This suggests that oocyte apoptosis at higher levels of DNA damage involves a TAp63-independent mechanism. We hypothesized that this mechanism requires TRP53 activity. Our data supports this hypothesis as females lacking TAp63 and TRP53 activity receiving high-doses radiation retain oocyte reserve and remain fertile. We will present our progress in delineating the role of TRP53 activity in oocytes and granulosa cells after radiation. Defining mechanisms regulating TAp63 and TRP53 activity in response to cellular damage will improve our understanding of how genotoxic treatments lead to oocyte loss.
1082. Design of Neutrophil-Specific Fluorescent Reporter Constructs for Ncf1 and Nfe2l2 to Characterize The Production of Reactive Oxygen Species During Influenza Virus Infection in Zebrafish
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Samuel Weafer, Brandy-Lee Soos, Benjamin King
Undergraduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Influenza virus is a major public health concern with an estimated 9-14 million infections per year in the US. There have been five influenza pandemics since 1889, and the 1918-1919 pandemic caused an estimated 21 million deaths. Influenza A virus (IAV) is one of four influenza serotypes and can cause severe respiratory infection and distress in affected individuals due to over-activation of the immune response. Basic research on how the innate immune system responds to influenza infection is necessary since seasonal influenza vaccines are not always effective due to virus antigenic drift and shift. Zebrafish embryos are valuable models to study the response to IAV infection in vivo. Fluorescent confocal imaging can be used to visualize how host immune cells interact with the virus. In zebrafish, IAV infection leads to a hyper-inflammatory state that includes the production of reactive oxygen species (ROS) by neutrophils. ROS function as pro-inflammatory signaling molecules and as oxidizing agents in lysosomal degradation. Production of ROS must be carefully balanced during IAV infection; it is critical to generate enough to clear infection while not causing oxidative stress and tissue damage. This balance is tightly regulated and ncf1 and nfe2l2 are two genes critical in the regulation of ROS. We are using Gateway cloning to create new fluorescent-reporter constructs for these genes that can then be used to generate new zebrafish lines to analyze gene expression patterns in vivo. These constructs are designed to express the reporter specifically in neutrophils by using the lysozyme c promoter.
1083. Fickle Finkle: One of a Kind – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Sydney Brown, Seth Ashby, Gavin Bressette, Sophie Charles, Melody Neely
Undergraduate Student Presentation
Faculty Mentor: Melody Neely
Abstract: Gordonia bacteria are often found in wastewater treatment biomass where they can cause excessive foaming, inhibiting the final breakdown of the wastewater byproducts. Recently, the application of Gordonia-specific bacterial viruses, called bacteriophage, to wastewater has proven beneficial to remove the excessive foaming. Bacteriophages (phages) are diverse bacterial viruses and extremely numerous with approximately 1031 existing in nature. Therefore, increasing our knowledge of Gordonia phages will provide a greater understanding of how phage can be used to aid in wastewater treatment. Gordonia terrae was used as a host to isolate the phage Finkle from a soil sample collected in Brewer, Maine. Finkle is classified as a singleton, meaning it does not share genetic similarity with other phage that have been previously isolated. Finkle also has a temperate lifestyle, meaning it has the ability to integrate into the host cell genome. The genome of Finkle contains 47,895 base pairs with a 66.6% GC content. Annotation was performed using bioinformatic tools such as HHPRED, PECAAN, Phamerator and PhagesDB to determine gene start sites and identify protein functions. A toxin/antitoxin system, which increases bacterial fitness, was identified in the ~80 genes annotated, while 33 of the genes encode proteins with unknown function. Annotating G. terrae phage genomes increases our understanding of how phages can be used in the management of bacteria in activated sludge wastewater treatment. In addition, studying Gordonia bacteria and their phages will deepen our understanding of both the medical and environmental applications of this microbial family.
1084. Perivascular Adipose Tissue is Distinct in Two Disease Populations
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Caitlin Stieber, Lucy Liaw
Graduate Student Presentation
Faculty Mentor: Lucy Liaw
Abstract: Background: Cardiovascular disease, which is the leading cause of death in the U.S., is tightly linked to obesity. To study this disease association, we use perivascular adipose tissue (PVAT) which surrounds most vessels and exerts a paracrine effect. We study PVAT in two patient populations: donors undergoing mitral valve repair (VR) surgery or coronary artery bypass graft (CABG). We hypothesize that due to lack of arterial disease VR donors will have a lower BMI, smaller adipocytes, and more adipocytes per area than CABG donors. Methods: PVAT was harvested from donors undergoing CABG and VR surgeries and was fixed, paraffin embedded, sectioned, and stained. Stained images were analyzed with ImageJ AdipoSoft to quantify number and size of adipocytes. Tissue samples were submitted for mass spectrometry proteomic analysis. Principle component analysis (PCA) plots were used to generate protein profiles for each sample. Results: VR donors had a BMI of 25.43, while CABG donors had an average BMI of 31.72. In VR PVAT, there was a trend of larger and fewer adipocytes, as compared to CABG PVAT. Analysis of PVAT from additional donors is ongoing. Lastly, PCA analysis showed that VR PVAT and CABG PVAT have distinct proteomic profiles. Conclusions: VR and CABG PVAT display unique features, both in donor demographics and at a molecular level. Our pilot analysis of adipocyte morphology suggests that PVAT from CABG donors may have more proliferative pre-adipocytes, leading to more cells of smaller size. This possibility will be assessed in future experiments, and we will further consider potential protein PVAT biomarkers of cardiovascular disease.
1085. Investigating the Interaction of Streptococcus agalactiae and Candida albicans in Vitro and in Vivo
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Kathryn Patenaude, Anna Lane, Robert T. Wheeler, Melody N. Neely
Graduate Student Presentation
Faculty Mentor: Melody N. Neely
Abstract: Treatment of opportunistic infections can be problematic because of a lack of understanding of how other organisms found in the localized environment play a role in the progression of infection. One factor that has been poorly studied is how bacteria and fungi interact together in the host, and how that may be influencing virulence. Both the fungus Candida albicans (C.a.) and the bacteria Streptococcus agalactiae (Group B Strep or GBS) are commensals that colonize the vaginal tract. While usually harmless in the human host, both organisms can cause opportunistic infections in immunocompromised patients, which can also progress to co-infections. What we don’t understand is how interactions between these organisms can affect the progression of infections caused by each pathogen or how they affect treatment outcomes. Previous in vitro work has analyzed interactions between other commensal bacteria and C.a., but there is not much known about how GBS and C.a. interact in co-infections and what influence that interaction may have on the effectiveness of current treatments. Research to date has revealed that C.a. can increase growth of GBS in vitro in nutrient poor media, even in the presence of antibiotics. Increased virulence during a co-infection in zebrafish larvae is observed suggesting a synergistic effect in vivo. Fluorescent microscopy also reveals increased growth and survival of C.a. in vivo during a coinfection compared to a solo infection. These data are highly relevant to treatment of human infections caused by these organisms as they are often found co-colonizing the same tissue environment.
1086. Anti-Inflammatory Effect(s) of Phenolic Extract from Wild Blueberries in Wound Healing
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Tolu Esther Adekeye, Natalie VandenAkker, Tyla Greenlaw, Dorothy Klimis-Zacas
Undergraduate Student Presentation
Faculty Mentor: Dorothy Klimis-Zacas
Abstract: Chronic wound care costs billions of dollars annually. Unresolved inflammation is a major factor that hinders healing of chronic wounds. Thus, there is a need to develop anti-inflammatory wound healing products. Polyphenols have been reported to improve wound healing. Thus, the objectives of this study are to examine the pre-clinical effect of a phenolic extract (PE) from wild blueberries (WB) on wound healing in rats. Phenolics were extracted from WB through the Folin-Ciocalteu method. The extract was incorporated into a gel and cream. Fifty-six Sprague-Dawley rats were classified into seven groups as: 1. Control (no treatment), 2. the cream carrier without the PE, 3. gel carrier without PE, 4. gel with 500 µg/ml of the PE, 5. cream with 500 µg/ml of PE, 6. gel with 1000 µg/ml of PE, and 7. cream with 1000 µg/ml of PE. Dorsal wounds were created on all the rats and treated according to the above groups for six days. Skin tissues were excised for histological analysis. Stained tissues were scanned with the light microscope and immune cells (neutrophils) were counted using Qu path software. Our analysis showed a decrease in the presence of inflammation with the gel-PE 500 µg/ml treatment compared with the other groups. Currently, we are analyzing proteins associated with the observed decrease in inflammation. Results from this project may benefit patients with chronic wounds and promote economic growth for wild blueberry farmers and the State of Maine.
1087. Rapgef Family Members Contribute To Erk Activation by Gs-coupled Receptors In Mouse Dorsal Root Ganglion Neurons
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Zaid Al-Abbasi, Derek Molliver, Ramaz Geguchadze
Graduate Student Presentation
Faculty Mentor: Derek Molliver
Abstract: Rap guanine nucleotide exchange factor (Rapgef) family members activate Rap/Ras signaling pathways by exchanging GTP for GDP. Four of the 6 Rapgefs have been identified as effectors of cAMP signaling. ERK signaling is required for some components of nociceptor sensitization, therefore cAMP signaling to ERK may represent a critical pathway in the induction of inflammatory hyperalgesia by Gs-coupled receptors (GsPCRs). Studies in heterologous systems suggest that activation of ERK downstream of GsPCRs is mediated by Rapgef2, either alone or in combination with PKA. In dorsal root ganglion (DRG) sensory neurons, phosphoproteomics analysis showed that Rapgef2 was amongst the top affected proteins during inflammation. All Rapgefs are expressed in DRG to varying degrees. Next, we examined the relative contributions of PKA and Rapgef2 in the activation (phosphorylation) of ERK (pERK) downstream of cAMP. Application of the cAMP analog 8-Br-cAMP to dissociated DRG neurons induced pERK. Consistently, the Rapgef2-selective cAMP analog N6-Phe-cAMP also showed a dose-dependent (150-1000 𝝁M) induction of pERK that was reversed by a Rapgef2 inhibitor, but not by PKA inhibitor H89, supporting selective activation of Erk by Rapgef2. Next, we examined whether endogenous Gs-coupled receptors induce pERK. RNA levels for 𝜷-adrenergic receptors Adrb1-3 and dopamine receptors Drd1, 5 were examined by quantitative PCR in mouse DRG neurons and a human DRG-derived cell line (HD10.6 cells). Adrenergic and dopaminergic agonists induced substantial pERK. These results provide evidence that GsPCRs activate ERK through Rapgef2 in DRG neurons.
1088. NOD/ShiLtJ Strain: A Mouse Model to Investigate the Regulation of Fetal Oocyte Attrition.
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Rose Besen-McNally, Ruby Boateng, Nathaniel Boechat, Ewelina Bolcun-Filas
Graduate Student Presentation
Faculty Mentor: Ewelina Bolcun-Filas
Abstract: In humans and mice, the ovarian reserve (OR) is established during a lengthy process that starts during early embryogenesis with germ cell specification and culminates in the first weeks after birth when primordial follicles (PF) are formed. OR establishment is an important process whereby the fertile lifespan of the female is established, and the OR determines not only how long ovaries will produce oocytes for fertilization but also the onset of menopause in humans. Fetal oocyte attrition (FOA) has been identified as a critical developmental event that regulates how many oocytes survive and contribute to the final OR. In addition to FOA, OR size and quality also depend on efficiency of meiotic recombination; chromosome asynapsis and unresolved double-strand breaks (DSB) lead to the exclusion of defective oocytes from the final OR by a checkpoint mechanism. There is limited understanding of how genetic factors modify these mechanisms that determine the OR. However, LINE-1 retrotransposon elements have previously been identified as playing a critical role in FOA in C57Bl/6 (B6) female mice. Retrotransposon elements are capable of excision and subsequent insertion anywhere in the genome, events that can cause DSBs, insertional mutagenesis, and affect expression of genes near insertion sites. The exact mechanism by which LINE-1 activity affects the OR remains unclear and has not been investigated in genetic backgrounds other than B6. High levels of LINE-1 expression are thought to cause additional DSBs during meiotic recombination and negatively affect oocyte survival. We hypothesized that mouse strains with large OR might exhibit oocyte evasion of FOA and/or quality checkpoint. As one instance of this, we found that NOD/ShiLt females have a larger and higher quality OR compared to the standard inbred B6 strain. Here we show greater oocyte survival in the FOA window of elimination in NOD/ShiLtJ than in B6 ovaries. To investigate one possible cause of FOA evasion, we determined LINE-1 expression levels in ovaries during prenatal stages, finding lower overall levels in NOD/ShiLtJ than in B6 ovaries. These observations support a role for LINE-1 as a regulator of OR size in mice and identify the NOD/ShiLtJ strain as a good model to investigate regulation of FOA and LINE-1 activity in female germline. Supported by R01 HD093778.
1089. Uncovering Candida albicans Factors that Modulate the Host Phagocyte Response
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Bailey Blair, Emma Bragdon, Robert Wheeler
Graduate Student Presentation
Faculty Mentor: Robert Wheeler
Abstract: Candida albicans is the 4th most common blood stream infection found in US hospitals. The first line of defense against these infections, is the innate immune system. Previous work using the larval zebrafish suggests that early immune response is critical in controlling C. albicans infection as a strong early phagocyte response promotes survival. However, is has been seen that C. albicans has strategies to evade the host immune system. Evidence suggests that the ability to transition from yeast to hyphal growth may facilitate immune evasion by limiting early phagocyte recruitment and uptake of Candida albicans. However, the mechanism by which C. albicans achieves this is unknown. To uncover factors important in innate immune evasion we utilized the transparent larval zebrafish infection model to screen C. albicans mutants for altered virulence and immune response. This screen identified 11 mutants that had greatly attenuated virulence, some of which also show an altered immune response. We saw that RBT1, which codes for a fungal cell wall protein and secreted peptides, plays a role in limiting neutrophil recruitment to the site of infection. On the other hand, lipases seem to play a role in limiting containment of fungi. Our results highlight the different mechanisms C. albicans employs to overcome the host immune system. This work will provide valuable insight how C. albicans limits recruitment of phagocytes as well as uptake by these cells, allowing it to escape destruction by the host immune system.
1090. Combining Regional Cell Composition Estimates with Bulk RNA Sequencing Allows for Refined Detection of Cell-Type-Specific Genetic Associations
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Brianna Gurdon, Niran Hadad, Maria Telpoukhovskaia, Sharon Yates, Jan Bjaalie, Catherine Kaczorowski
Graduate Student Presentation
Faculty Mentor: Catherine Kaczorowski
Abstract In addition to aging, strong genetic components have been associated with Alzheimer’s disease(AD) progression. Bulk RNA-sequencing is often used to detect transcriptomic differences that occur with age and AD; however, these methods can be influenced by changes in cell composition, which can then confound differential gene expression analyses. By incorporating cell-type proportion estimates measured using immunohistochemistry(IHC) with bulk RNAseq data, we can correlate cell composition with gene expression and performed gene set enrichment analyses to better understand the biological pathways implicated with disease progression. The QUINT workflow was used to quantify neurodegeneration(NeuN), gliosis(Iba1&Gfap), and amyloid pathology(Aβ1-42) in hemibrains of 40 mice from the AD-BXD genetic reference panel. This cell composition data was then integrated with bulk RNAseq data to correlate strain averages of gene expression to individual hippocampal and prefrontal cortex cell coverage. There is an increase in Gfap and Iba1-positive cells, and Aβ1-42 pathology, in middle-aged(14m), compared to adult(6m) mice. Gene expression correlated with glial load is highly enriched for pathways predominately in the immune system category. When specifically correlating hippocampal glial cell load with disease-associated microglial and astrocyte marker genes, there were a number of significant correlations(p<0.05) at the adult timepoint (including Clu, Ctsb, Ctsl). Seeing that differences in gene expression are indeed related to cell composition, previous findings nominating enriched pathways based on bulk differential gene expression alone may be misrepresented. In the future, cell composition can be included as a covariate in analyses of bulk gene expression to increase the power to identify cell-type-specific genetic associations.
1091. Influenza A Virus Infections Measured by Respiratory Burst Assay
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Brandy-Lee A. Soos, Alec Ballinger, Mykayla Weinstein, Benjamin L. King
Graduate Student Presentation
Faculty Mentor: Benjamin L. King
Abstract: Influenza A virus (IAV) is a major health concern since it can cause severe lung infections. The innate immune system is the host’s first defense against pathogens, including IAV. The innate immune system consists of multiple cells including neutrophils and macrophages. Neutrophils are phagocytes that engulf and destroy pathogens through the production of reactive oxygen species (ROS). The production and release of ROS is a process called the respiratory burst response that begins with NADPH oxidase (NOX). Because ROS is highly reactive, levels must be tightly controlled to limit host tissue damage. The long-term goal of our research is to learn how to balance the respiratory burst response following IAV infection. Using a zebrafish model of IAV infection, our preliminary studies show that limiting ROS production improves survival. We hypothesize that reducing the respiratory burst response will limit tissue damage and improve survival. To test this hypothesis, a respiratory burst assay is used to measure the respiratory burst capacity. First, ROS is induced using phorbol myristate acetate and then ROS levels are measured. In these assays, we measure the amount of a fluorescent product, dichlorofluorescein, that is generated when ROS oxidases 2,7-dihydrochlorofluorscein diacetate. Ongoing studies have shown that the respiratory burst response decreases by 48 hours post infection and gradually rebounds over the course of infection. We are currently measuring changes in the respiratory burst response with and without the NOX inhibitor, GSK205739. These studies will help identify the molecular mechanisms that regulate the respiratory burst response.
1092. Characterization of the Polymorphic Toxin System in Mycobacterium Prophage McProf
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Xuyang Gu, Sarah McCallister, Jaycee Cushman, Anna Schumann, Sally Molloy
Graduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Non-tuberculosis mycobacteria such as Mycobacterium abscessus are emerging pathogens of immunocompromised patients. M. abscessus isolates are often multi- or totally drug resistant and are a major public health threat. Understanding the mechanisms of antibiotic resistance is crucial to improve treatments. The majority of M. abscessus isolates carry one or more prophages, integrated viral genomes, that are enriched in toxin genes and predicted to play a role in virulence.The Molloy lab recently demonstrated that prophages in the related pathogen M. chelonae increase mycobacterial antibiotic resistance. A polymorphic toxin system encoded by the prophage McProf appears to play a role in the increased antibiotic resistance. The toxin system includes three genes that encode an ESAT6-like protein (gp99), a polymorphic toxin (gp98) and a cognate immunity protein (gp97) but the function of these genes has not yet been characterized. The toxin system is hypothesized to play a role in antagonistic interactions with non-toxin producing cells and cell signaling with other toxin-producing cells. In this study, we will confirm that the toxin system has toxic activities and facilitates antagonistic interactions with non-toxin producing bacteria. The toxin system genes will be cloned into mycobacterial vectors with either inducible or constitutive promoters. The toxin will be tested for toxic activities in cells that encode the toxin with and without the immunity protein gene and measuring cell density after induction. We will determine if the toxin producing cells are antagonistic against cells that don’t produce the corresponding immunity proteins in co-culture experiments.
1093. Toxicity of Lanthanide Series Rare Earth Elements in Caenorhabditis elegans
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Michael Croft, Jennifer Newell-Caito
Undergraduate Student Presentation
Faculty Mentor: Jennifer Newell-Caito
Abstract: The production of rare earth elements (REEs) in the last 20 years has significantly increased, due to the use of REEs within a variety of applications such as fiber optics, batteries, medicines, and purifications. Over 99% of these elements accumulate in landfills and subsequently pollute local ecosystems. Although the toxicity of these metals is assumed to be low, their increased use and lack of long-term studies requires further investigation. These metals have been shown to cross biological barriers and bioaccumulate. The nematode Caenorhabditis elegans has been used in a variety of toxicity studies; their short lifespan and high homology to humans make them ideal for biological monitoring of toxins. Therefore, we hypothesized that C. elegans exposed to REEs would have altered survival and lifespan parameters. We selected four commonly used lanthanide series metals for investigation, lanthanum (La), cerium (Ce), erbium (Er), and ytterbium (Yb). Dose-response survival curves found that the C. elegans were highly sensitive to Ce, followed by Yb, Er, and La. The LD50 values were 1.12 ± 0.076 mM, 1.52 ± 0.116 mM, 1.42 ± 0.268 mM, and 17.1 ± 0.057 mM, respectively. In addition to survival curve analysis, lifespan and reproductive success analysis were performed, showing significant differences between the metals. These findings demonstrate detrimental effects of chronic exposure to lanthanide metals in nematodes. Our results suggest that similar effects may be occurring ecologically at electronic waste disposal and mining sites, with implications for human health.
1094. Screen to Find Regulators of Candida albicans Drug Tolerance During Co-cultures with Pseudomonas aeruginosa
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Nikhil Vaidya, Siham Hattab, Robert T. Wheeler
Undergraduate Student Presentation
Faculty Mentor: Robert T. Wheeler
Abstract: Candida albicans is an opportunistic pathogen that can cause invasive systemic infections in immunocompromised patients—with 40% mortality. C. albicans is commonly isolated from co-infections with the bacterium Pseudomonas aeruginosa, which is the most prevalent pathogen in cystic fibrosis and mechanically ventilated patients, together forming persistent biofilms on catheters and implants. Treatments for these polymicrobial infections are challenging, as interactions between organisms and how they affect drug efficacy are not well understood. The antifungal drug fluconazole (FLC) is a primary treatment for candidiasis, yet C. albicans exhibits multiple FLC resistance mechanisms. Interestingly, recently published work has shown that C. albicans loses drug tolerance and exhibits higher susceptibility to FLC during co-cultures with P. aeruginosa. To understand how this drug-bacterial combination works against C. albicans, we are conducting a genetic screen for negative regulators of FLC tolerance in C. albicans during in vitro co-cultures with P. aeruginosa. We will screen a library of 600+ homozygous single gene mutants of C. albicans grown together with P. aeruginosa and FLC and will identify mutants with increased survival in the presence of P. aeruginosa and FLC. A secondary screen will be performed in mutants with increased survival to investigate whether the increased survival was due to increased FLC resistance or increased tolerance to the combination of P. aeruginosa and FLC. Investigating single gene deletions may elucidate pathways mediating the interaction between the two organisms, opening possibilities of new drug targets for treatment.
1095. Investigating the Sexually Dimorphic Role of Corticotropin-Releasing Hormone in Neonatal Trauma-Induced Pain-Vulnerability
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Megan Tomasch, Mike Burman
Graduate Student Presentation
Faculty Mentor: Mike Burman
Abstract: Neonatal intensive care units (NICUs) provide life-saving care for preterm and sick neonates, but many of these procedures are painful and stress-inducing. Neonatal medical trauma results in an increased susceptibility to chronic pain, anxiety disorders, and depression, that manifests in later life following a subsequent injury or psychological stressor. Using a “2-hit model” of juvenile pain vulnerability, our lab has successfully modeled this in rats. To accomplish this, we subjected male and female neonatal rats to a common NICU manipulation (e.g., painful needle-prickings from PD 1 to PD 7), followed by a second, activating, injury or stressor (e.g., foot shock) on PD 23, and observed a tactile hypersensitivity in both sexes. Although the neurobiological mechanisms remain unclear, cells expressing corticotropin releasing factor (CRF+ cells) have been implicated in a sexually dimorphic manner. In males, but not females, pain-vulnerability is associated with alterations to CRF cells in the central amygdala (CeA). Females must then utilize a different mechanism, and CRF cells of the hypothalamus—specifically the paraventricular nucleus (PVN) of the hypothalamus—are a likely candidate, as neonatal trauma leads to sex differences in hypothalamic activation and changes CORT expression in females. We hypothesize that the immediate and lasting consequences of neonatal trauma result from changes to CRF+ cells in the CeA and PVN, including altered synaptic transmission and intrinsic excitability. To test this hypothesis, we will implement chemo- and optogenetic manipulations of CRF cells in the CeA and PVN both behaviorally (in vivo) and electrophysiologically (ex vivo slice preparation).
1096. Integrating Molecular Profiles with Clinical Outcomes in Cancer Patients from Rural Maine
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Michael Babcock, Benjamin King
Graduate Student Presentation
Faculty Mentor: Benjamin King
Abstract: Colon cancer is the second most deadly cancer and symptoms do not manifest until tumors are in advanced stages and despite diagnostic advancements and new treatment regimens, patient survival rates remain low. Molecular profiling reveals a large amount of genomic data during colon cancer subtyping; however not all findings are incorporated for patient clinical management. Many additional mutations occur in crucial biological pathways known to be dysregulated in colorectal tumors. In a previous study, we found that established prognostic/therapeutic markers and additional molecular features correlate with lung cancer patient outcomes. We propose that a similar stratification model can be used to classify colorectal adenocarcinoma patients to improve prognostic/therapeutic outcome. Clinical pathology data from colon cancer patient tumor specimens were analyzed for mismatch repair deficiency, microsatellite instability status, and genomic profiles. Findings were integrated with clinicopathological data using standard R software. Principal component analysis classified mutational patterns. Categorical relationships were performed by pairwise association studies using Chi-square and Fisher’s exact tests. Kaplan-Meier survival curves demonstrated the prognostic value of new categorical classifications. Integration of clinical pathology and molecular profiling data of colorectal tumors from rural Maine cancer patients were compared with the literature. The identification of a novel colon cancer molecular classification could be used to improve patient outcomes.
1097. Integrin and Dystroglycan Protein Localization in Muscle Cell Membranes in Dystroglycan and Dystroglycanopathy Mutants
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Mary Astumian, Prakash Raut, Clarissa Henry
Graduate Student Presentation
Faculty Mentor: Clarissa Henry
Abstract: Dystroglycanopathies are progressive diseases that vary in severity and affect muscle and neurological health. The transmembrane proteins dystroglycan and integrin, link the actin cytoskeleton inside the muscle cell to extracellular matrix (ECM) outside the cell maintaining cellular attachments. To function properly, integrins need to cluster in the muscle cell membrane and dystroglycan needs to be glycosylated. Several zebrafish models of the human dystroglycanopathies and mutations of dystroglycan and integrin have been created. Both dystroglycan and integrin bind to the ECM protein laminin. Laminin deposition and muscle health in zebrafish dystroglycan mutants and integrin-alpha7 mutants improved after oxidized nicotinamide adenine dinucleotide (NAD+) treatment. But NAD+ did not improve muscle health in the one dystroglycan glycosylation mutant tested so far. To explain the lack of improvement, one hypothesis is that hypoglycosylated dystroglycan protein physically interferes with integrin clustering in the membrane, preventing normal integrin-ECM binding activity. The localization of dystroglycan and integrin proteins relative to each other at the muscle cell membrane is hypothesized to be important and will be measured using both confocal and superresolution microscopy. NAD+ treated versus untreated zebrafish will be analyzed to assess the average distance between the molecules of dystroglycan and integrin-alpha7 at the myofiber membranes.
1098. Veterinary Immersion Network
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Zachary Inniss, Anne Lichtenwalner
Undergraduate Student Presentation
Faculty Mentor: Anne Lichtenwalner
Abstract: Coming to UMaine, I was under the impression that the vast majority of the people in my major had the same opportunities in exploring veterinary medicine. But I was wrong. Many of my classmates do not have any vet hours for many different reasons, such as difficult accessibility. For example, there are more emergency hospitals in a 20-mile radius from where I live than in the entire state of Maine. Another factor that proves challenging in gaining veterinary experience is that the veterinarians in their area are unwilling to take these students on because the students lack experience. Feeling defeated due to the lack of support and opportunities, many students see no other option but to change career paths. A potential solution to this complex problem is the creation of The Veterinary Immersion Network. I hypothesize that the Veterinary Immersion Network will help students gain well-rounded experience and solidify their career choice in the veterinary field. The Veterinary Immersion Network’s goal is to provide insight, opportunity, and support to anyone interested in veterinary medicine. We can achieve this goal by creating a website where veterinarians can interact with students aspiring to become the next generation. When students access the site, they receive access to resources like testimonials and interviews from different veterinary professionals, modules to learn fundamental clinical skills for employment /volunteer/internships, and a support system of peers that share a love of animals.
1099. CTHRC1 Suppresses Adipogenesis and Modulates Lipid Composition
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Matthew Siviski, Igor Prudovsky
Graduate Student Presentation
Faculty Mentor: Igor Prudovsky
Abstract: The development of novel approaches to prevent obesity is imperative given that 2016 marked the first year in decades that the life expectancy for adults in the United States decreased, largely due to a rise in obesity-related comorbidities. The secreted factor, collagen triple helix repeat-containing 1 (CTHRC1), is a novel suppressor of white adipose tissue formation (adipogenesis). In order to elucidate the molecular mechanisms by which CTHRC1 suppresses adipogenesis, we have developed an in vitro model to study the effects of CTHRC1 on the expression levels of the adipogenic transcription factors that coordinate preadipocyte-to-adipocyte differentiation. Our data show that CTHRC1 suppresses both the transcript (mRNA) and protein expression levels of CCAAT/enhancer-binding protein delta (C/EBPδ), C/EBPα, peroxisome proliferator-activated receptor gamma (PPARγ), and other critical adipogenic transcription factors that give rise to a mature, lipid-rich adipocyte. In this context, our data suggest that CTHRC1 may function in part by increasing the expression of SRY protein box 9 (SOX9), a protein that suppresses adipogenesis by inhibiting the promoter regions of C/EBPβ/δ and their corresponding gene expression. Moreover, comparative mass spectrometry analysis of the lipid composition of subcutaneous and visceral adipose tissue depots reveals significantly increased levels of unsaturated, 18-carbon fatty acyl triglyceride species (i.e., “bad fat”) in Cthrc1-null mice in comparison to wildtype control mice. Therefore, these data suggest there are important metabolic implications of CTHRC1 signaling given its ability to beneficially modulate triglyceride composition in vivo. Collectively, our results show that CTHRC1 is both a novel suppressor of white adipogenesis and unsaturated long-chain fatty acid triglyceride levels, and thus may possess the potential to be utilized for the design of future, efficacious therapies to combat the obesity epidemic and obesity-related comorbidities.
1100. Notch Signaling Regulates PVAT Function During Diet-induced Obesity
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Chenhao Yang, Anne E. Harrington, Larisa M. Ryzhova, Lucy Liaw
Graduate Student Presentation
Faculty Mentor: Lucy Liaw
Abstract: Obesity is an established risk factor for cardiovascular diseases (CVD) and possibly shares molecular and cellular disease mechanisms as CVD. As a component of the vasculature, perivascular adipose tissue (PVAT) is as a critical regulator of vascular function due to its anatomical proximity to the vascular wall. In addition to a broad role in embryonic development, Notch/Rbp-jk signaling plays a crucial role in regulating metabolic homeostasis. Suppression of Notch signaling components was reported to induce beige phenotypes within white adipose tissue. We studied how Notch/Rbp-jk signaling and potential downstream pathways regulate PVAT phenotype. We generated mouse models with adipose tissue specific knockout of Rbpj genes or overexpression of Notch intracellular domain using Adipoq-Cre driver and examined their physiology, histology, and expression of metabolic and vascular relaxation pathway components as compared to control non-Cre mice. Our data showed that Notch signaling was activated in PVAT during high fat diet (HFD) treatment. Expression of Notch signaling component including RBPJ-k was increased during differentiation of PVAT. Moreover, PVAT from adipocyte-specific RBPJ-k conditional null mice showed alterations in the vasorelaxation pathway including eNOS, with a potential link through PI3/AKT signaling. Results of vessel wire myography experiment further confirms the influence of Notch signaling in PVAT on vascular reactivity. In summary, our studies show that Notch signaling regulates metabolic homeostasis of adipose tissue including PVAT. In addition, Notch signaling potentially regulates PVAT-mediated vasorelaxation through eNOS pathways.
1101.Electrophysiological Recordings in Humans Using a Novel Microneedle Array Device – Presentation withdrawn from judging
Submission Type: Virtual Presentation
Submission Category: Biomedical Sciences
Author(s): Lydia Caron, Sarrah Marcotte, Leonard Kass, Rosemary Smith, Magdalena Blaskiewicz, Kristy Townsend
Undergraduate Student Presentation
Faculty Mentor: Leonard Kass
Abstract: Peripheral neuropathy is a devastating disease marked by the progressive loss of distal nerve function which starts at the skin and moves proximally, subsequently causing tingling, pain, hypoesthesia, and in some cases need for limb amputation. Earlier detection offers hope for better treatment and prevention. Neuright, Inc. has developed a novel 9 channel microneedle array device that can detect transdermal neural activity in mice in the basal state, in induced diabetic neuropathy mouse models, and now in humans in the basal state. The focus of this study was to survey and evaluate any neural activity recorded from humans using this microneedle device. The microneedle array was inserted into the lateral calf of two healthy human subjects under resting conditions and recordings were obtained for several minutes. The participants were occasionally asked to flex their toes, which marked an immediate and noticeable change in the electrophysiological recordings delivered from the array. These results showed that the microneedle array was able to record several different types and categories of electrical activity: single action potentials, patterns of action potentials, compound action potentials and electromyography from muscle (CAPs/EMGs), bursts of CAPs/EMGs, as well as train-like patterns of CAPs/EMGs. Expanding upon this method of recording from humans in the future, observable differences in the characteristics of these electrophysiological recordings may provide a diagnosis of peripheral neuropathy in diabetic patients. Acknowledgment: We thank Julia Towne for her help in constructing the microneedle array.
1102. Bone Regeneration: Cellulose Nanofibers and Additional Composites – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Shanna Scribner, Sahar Roozbahani, Michael Mason
Graduate Student Presentation
Faculty Mentor: Michael Mason
Abstract: Aging, disease, and traumatic injuries may result in weakening or loss of bone tissues. Although bone has the natural ability to regenerate for small fractures or breaks, a large loss of bone volume may require surgical interventions to replace that bone. Current surgical replacements have significant disadvantages that are pushing researchers to look in other areas for replacements, such as biomaterials. Many biomaterials have flexible properties and are biocompatible, making them ideal for implantation research. Cellulose nanofibers (CNF) are a particularly popular material, having many applications such as drug delivery, tissue engineering, and regeneration. CNF has great strength and stiffness, is light-weight, biodegradable, biocompatible, and tunable mechanical properties which make it desirable for bone scaffolding. The degree of alignment in CNF-based scaffolds positively correlates with mechanical properties as well as cell alignment, differentiation, and adhesion. In this research, unilateral elongation force is used to stretch thin CNF films on latex which has proven to provide consistent, effective results. Further testing into increasing alignment of the fibrils using other composites such as hydroxyapatite and polyethylene glycol are ongoing.
1103. Determining Septin localization With α-Arrestin Deleted Strains of Saccharomyces cerevisiae
Submission Type: Poster
Submission Category: Biomedical Sciences
Author(s): Ryan Andrick, Joshua Kelley
Undergraduate Student Presentation
Faculty Mentor: Joshua Kelley
Abstract: Interactions between cells in Saccharomyces cerevisiae provides a model for spatial signaling through G-protein coupled receptors. These transmembrane receptors are conserved in humans and play a role in endocrine signaling, immune function, and neuron function, among others. The yeast mating pheromone binds to the Ste2 receptors, which are then bound by α-arrestins to promote ubiquitylation and endocytosis. Endocytosis of the receptor promotes the ability of the yeast to track a gradient of mating pheromone. Gradient tracking also requires the function of cytoskeletal proteins called septins, which form structures at the periphery of the mating projection. We are testing whether the yeast arrestins are required for proper septin function. First steps of determining the effects Rog1 has on septin localization are to transform yeast strains to lacking Rog1 and have fluorescently tagged septins to compare the deletion morphologies to the wild type. Determining whether septin placement is linked to the locations of endocytosis of the receptor is important for polarization and gradient tracking. Further methods to quantify this would be to fluorescently tag Ste2 as well as α-arrestins for comparing the similarity of their localization during the pheromone response.
1104. Phenolic Extract(s) from Wild Blueberries promotes Wound Re-epithelialization
Submission Type: Virtual Presentation
Submission Category: Engineering and Information Sciences
Author(s): Tolu Esther Adekeye, Natalie VandenAkker, Loryn Porter, Dorothy Klimis-Zacas
Graduate Student Presentation
Faculty Mentor: Dorothy Klimis-Zacas
Abstract: Adequate wound re-epithelialization is important for wound healing. However, this is a challenge in chronic wounds such as diabetic and ischemic ulcers. Bioactive compounds such as phenolic (PE) and anthocyanin (ACN) fractions from Wild Blueberry (WB) have been reported to promote wound closure and angiogenesis. Thus, the objective of this study is to examine the effect of PE and ACN fractions at different concentrations on wound re-epithelization in rats. Phenolics and anthocyanin fractions were extracted from WB through the Folin-Ciocalteu method, and their composition was determined by HPLC. The extracts were resuspended in distilled water. Fifty-six Sprague-Dawley rats were classified into seven groups as follows: 1. Control (no treatment), 2. PE 250µg/dl, 3. PE 500µg/dl, 4. PE 1000µg/dl, 5. PE+ACN 250 µg/dl, 6. PE+ACN 500 µg/dl, and 7. PE+ACN 1000µg/dl. Dorsal wounds were created on all the rats and treated according to the above groups for 7 days. Skin tissues were excised and fixed for histological analysis. Tissues were stained with H&E and scanned with Olympus light microscope. Re-epithelization was measured and assessed using Qu path software. Our analysis showed adequate and discrete wound re-epithelization with PE 500 µg/dl treatment compared to the other groups. Results from this study may benefit patients with chronic wounds through the development of clinical wound healing products and will promote economic growth for wild blueberry growers and the state of Maine.
1105. Effects of Binge-Eating on Impulsivity, Compulsivity, and Reward Sensitivity Across Strain and Sex
Submission Type: Virtual Presentation
Submission Category: Engineering and Information Sciences
Author(s): Logan Douglas, Kristen O’Connell
Graduate Student Presentation
Faculty Mentor: Kristen O’Connell
Abstract: After a break-up, maybe you eat ice cream to comfort yourself. When you finish studying for a big test, you might reward yourself with a treat. While people commonly understand eating as a metabolic need, in an age of excess, many people eat for pleasure or the positive feeling eating good food brings us. Eating for pleasure, or hedonic feeding, is less understood and well-researched compared to eating to fulfill our homeostatic needs. One poignant example of hedonic feeding is binge-eating. Binge-eating refers to the overconsumption of food in a distinct period of time (~2 hours) accompanied with dysregulation of impulsive and compulsive eating behaviors. (Hudson et al. 2007) In a mouse model, intermittent access to a high-fat or palatable food induces binge-eating behavior. The neural controls of binge-eating are thought to include not only traditional homeostatic controls of food intake and behavior like the hypothalamus but also reward-circuitry in the mesolimbic system. In part due to this existing overlap between circuits, the effect of binge-eating on substance abuse-related phenotypes such as compulsive behaviors, impulsivity, reward sensitivity, and more are of interest in the study of the effects of binge-eating on behavior. In this review, I present the established literature on how chronic and intermittent access to high-fat diet affect compulsivity/impulsivity related phenotypes and reward sensitivity in studies of addiction. This will be presented alongside a discussion of current gaps in the research and preliminary data regarding the importance of genetic diversity in evaluating motivation for palatable food reward.
1106. Gordonia Phage Periwinkle – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Natural Sciences
Author(s): Abigail Dichiara, Emma Boudreaux, Sophie Childs, Amy Handy, Sam Kovacs. Alison Kueck, Parker Landsbergen, Sally Molloy
Underraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Gordonia are ubiquitous Actinobacteria that are frequently isolated from soil and water but can also cause infections in immunocompromised individuals. Studying the content of Gordonia bacteriophage (a bacterial virus) genomes will help us better understand the physiology of the bacterial host and provide opportunities to improve treatment of bacterial infections in general. Using SEA-PHAGES protocol, the novel Gordonia bacteriophage Periwinkle was isolated from a manure sample collected at Roger’s Farm, Orono, ME, using the host bacterium Gordonia terrae 3612. Periwinkle was characterized by plaque morphology, virion morphology, restriction endonuclease digest patterns, host range, and genetic sequencing. Periwinkle is one of 22 cluster DN temperate bacteriophages. The genome is 55,657 nucleotides long, has a GC content of 62.9%, and encodes 113 putative genes. Consistent with a temperate phage, Periwinkle encodes a tyrosine integrase (gp57) and an immunity repressor (gp58). Approximately 41% of the genes (46 genes) have no known function. The increased knowledge and identification of Gordonia bacteriophage genomes such as Periwinkle, especially the uncharacterized genes, can advance our understanding of bacterial and phage evolution.
1107. Novel Cluster CZ phage Oregano: Friend & Foe to Bacteria – Presentation withdrawn from judging
Submission Type: Poster
Submission Category: Natural Sciences
Author(s): Alexander Russell , Veronica Chun , Oyku Goktug , Hannah Lembree , Dorian Royal , Annika Savage, Makayla Sisco , Maple Waltner
Underraduate Student Presentation
Faculty Mentor: Sally Molloy
Abstract: Antibiotic resistance is a growing threat to public health, particularly for immunocompromised patients that are vulnerable to bacterial infections. Bacteriophages (phages) are viruses that infect bacteria. Temperate phages can integrate their genomes into the bacterial genome and their genes have the potential to increase bacterial fitness and drug resistance during this lysogenic infection. Lytic phages replicate and lyse the bacteria to release phage progeny and can serve as an alternative treatment to drug-resistant bacterial infections. To learn more about how phages can play these two opposing roles, we isolated the novel Gordonia phage, Oregano, from a soil sample in Maine. The genome of Oregano is 47,575 bp in length with a GC content of 66% and encodes 82 genes. Oregano is one of 20 members of the CZ4 cluster. Oregano is a temperate phage and encodes two tyrosine integrases and an immunity repressor. Genes 44 and 45 encode a putative VapBC toxin/antitoxin system, with the potential to degrade cellular RNA during cell stress such as superinfection by a phage or exposure to antibiotics. In future research lysogens of Oregano will be isolated and analyzed for superinfection immunity and changes in drug resistance.