Laboratory and Basic Science Research Commons^™

Atomoxetine Enhances Specific Dimensions Of Cognitive Performance In A Rodent Strategy Shifting Assay, Jessica Ivanov

Rowan-Virtua Research Day

Title: Atomoxetine enhances specific dimensions of cognitive performance in a rodent strategy shifting assay

Authors: Jessica Ivanov, Christopher P. Knapp, Barry D. Waterhouse, Rachel L. Navarra

Objective: Cognitive flexibility, a domain of executive function, supports adaptive shifts in behavior in response to changing environmental demands and task contingencies. Deficits in this capacity are common to neuropsychiatric disorders such as Attention Deficit Hyperactivity Disorder (ADHD), where improper regulation of the catecholamine transmitters dopamine (DA) and norepinephrine (NE) within the prefrontal cortex (PFC) has been implicated. Atomoxetine (ATX), a selective NE transporter (NET) inhibitor, elevates levels of NE and DA in the …

Direct Synthesis Of Cerium Oxide Nanoparticles In Reducing Sugars: Enhanced Ce3+ Surface Density For Biological Application, Balaashwin Babu, Elayaraja Kolanthai, Craig J. Neal, Samarah V. Harb, Udit Kumar, Yifei Fu, Sudipta Seal

Rowan-Virtua Research Day

Cerium oxide nanoparticles (CNPs) are recognized for their ability to scavenge reactive oxygen species (ROS), making them promising candidates for mitigating oxidative damage in biomedical applications. However, many conventional synthesis methods limit the formation of Ce³⁺ states, which are critical for this antioxidant function. Building upon previous findings that glucose can promote Ce³⁺ formation, this study investigates the broader impact of both reducing (glucose, fructose, galactose) and non-reducing (dextran, sucrose, cyclodextrin) natural sugars on CNP synthesis. CNPs were synthesized in the presence of these sugars, and the surface densities of Ce³⁺ were measured. Results showed that reducing sugars significantly increased …

Modulation Of Opioid Receptor Expression In The Ventral Tegmental Area Following Stress Exposure In Rats, Maya Patel, John Tkaczynski, Jordan Riser, Nicole Shellenbarger, Jin Park, Daniel Manvich, Daniel J. Chandler

Rowan-Virtua Research Day

Background: The ventral tegmental area (VTA) contains dopamine-producing neurons projecting to various brain regions. VTA dysfunction is linked to addiction and depression. Delta opioid receptor upregulation relates to chronic pain, inflammation, cancer, and early adversity. Kappa receptors in the VTA influence stress, drug-seeking, mood, and reward. Notably, chronic substance abuse upregulates the κ-receptor/dynorphin system, and the opioid system regulates social interaction needs.

Hypothesis: Stress will upregulate opioid receptors.

Methods: We compared group-housed and individually-housed rats using stress tests, analyzing behavior and quantifying VTA opioid receptor expression.

Results: Social isolation upregulated delta and kappa opioid receptors in …

Single-Molecule Studies Reveal The Off-Pathway Early Paused State Intermediates As A Target Of Streptolydigin Inhibition Of Rna Polymerase And Its Dramatic Enhancement By Gre Factors, Anatolii Arseniev, Mikhail Panfilov, Georgii Pobegalov, Alina Potyseva, Polina Pavlinova, Maria Yakunina, Jookyung Lee, Sergei Borukhov, Konstantin Severinov, Mikhail Khodorkovskii

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Antibiotic streptolydigin (Stl) inhibits bacterial transcription by blocking the trigger loop folding in the active center of RNA polymerase (RNAP), which is essential for catalysis. We use acoustic force spectroscopy to characterize the dynamics of transcription elongation in ternary elongation complexes (ECs) of RNAP in the presence of Stl at a single-molecule level. We found that Stl induces long-lived stochastic pauses while the instantaneous velocity of transcription between the pauses is unaffected. Stl enhances the short-lived pauses associated with an off-pathway early paused state intermediates of the RNAP nucleotide addition cycle. Unexpectedly, we found that transcript cleavage factors GreA and …

A Homogeneous Time-Resolved Fluorescence Screen To Identify Sirt2 Deacetylase And Defatty-Acylase Inhibitors, Jie Yang, Joel Cassel, Brian C Boyle, Daniel Oppong, Young-Hoon Ahn, Brian P Weiser

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Human sirtuin-2 (SIRT2) has emerged as an attractive drug target for a variety of diseases. The enzyme is a deacylase that can remove chemically different acyl modifications from protein lysine residues. Here, we developed a high-throughput screen based on a homogeneous time-resolved fluorescence (HTRF) binding assay to identify inhibitors of SIRT2's demyristoylase activity, which is uncommon among many ligands that only affect its deacetylase activity. From a test screen of 9600 compounds, we identified a small molecule that inhibited SIRT2's deacetylase activity (IC50 = 7 μM) as well as its demyristoylase activity (IC50 = 37 μM). The inhibitor was composed …

Distinct Expression Patterns Of Hedgehog Signaling Components In Mouse Gustatory System During Postnatal Tongue Development And Adult Homeostasis, Archana Kumari, Nicole E Franks, Libo Li, Gabrielle Audu, Sarah Liskowicz, John D Johnson, Charlotte M Mistretta, Benjamin L Allen

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The Hedgehog (HH) pathway regulates embryonic development of anterior tongue taste fungiform papilla (FP) and the posterior circumvallate (CVP) and foliate (FOP) taste papillae. HH signaling also mediates taste organ maintenance and regeneration in adults. However, there are knowledge gaps in HH pathway component expression during postnatal taste organ differentiation and maturation. Importantly, the HH transcriptional effectors GLI1, GLI2 and GLI3 have not been investigated in early postnatal stages; the HH receptors PTCH1, GAS1, CDON and HHIP, required to either drive HH pathway activation or antagonism, also remain unexplored. Using lacZ reporter mouse models, we mapped expression of the HH …

Rewiring The Sex-Determination Pathway During The Evolution Of Self-Fertility., Yongquan Shen, Shin-Yi Lin, Jonathan Harbin, Richa Amin, Allison Vassalotti, Joseph Romanowski, Emily Schmidt, Alexis Tierney, Ronald E Ellis

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Although evolution is driven by changes in how regulatory pathways control development, we know little about the molecular details underlying these transitions. The TRA-2 domain that mediates contact with TRA-1 is conserved in Caenorhabditis. By comparing the interaction of these proteins in two species, we identified a striking change in how sexual development is controlled. Identical mutations in this domain promote oogenesis in Caenorhabditis elegans but promote spermatogenesis in Caenorhabditis briggsae. Furthermore, the effects of these mutations involve the male-promoting gene fem-3 in C. elegans but are independent of fem-3 in C. briggsae. Finally, reciprocal mutations in these genes show …

Interactions Between Repetitive Mild Traumatic Brain Injury And Methylphenidate Administration On Catecholamine Transporter Protein Levels Within The Rodent Prefrontal Cortex, Anna Abrimian, Eleni Papadopoulos, Christopher P. Knapp, J. Loweth, Barry Waterhouse, Rachel Navarra

Rowan-Virtua Research Day

It is theorized that low concentrations of dopamine (DA) and norepinephrine (NE) within in the prefrontal cortex (PFC) following traumatic brain injury (TBI) leads to increased risky behavior. Our lab has shown that repeated mild TBI (rmTBI) sex-differentially increases risky behavior in a rodent model. Methylphenidate (MPH) is a psychostimulant drug used to treat symptoms of Attention-Deficit Hyperactivity Disorder (ADHD), also driven by a hypo-catecholaminergic PFC. MPH elevates catecholamine levels by blocking DA and NE transporters, DAT and NET. While the potential of psychostimulants to treat post-TBI symptoms have been explored, the effects of sub-chronic MPH on transporter levels following …

Efficacy Of Mcl-1 Inhibitors In Multiple Myeloma Cells Resistant To Bortezomib, Emily Nelson, Omar S. Al-Odat, Sabrina M. Paparo, Daniel A. Guirguis, Gabriella Yao, Manoj Pandey, Subash Jonnalagadda, Tulin Budak-Alpdogan

Rowan-Virtua Research Day

Multiple myeloma (MM) is a type of cancer that affects plasma B cells. Patients with MM often experience frequent relapses and can develop resistance to drugs. As a medical researcher, it is important to understand the role of Mcl-1 in preventing intrinsic apoptosis and drug resistance. Mcl-1 belongs to the anti-apoptotic subgroup of Bcl-2 family proteins and plays a crucial role in these processes. Mcl-1 plays a crucial role in driving disease progression and contributing to drug resistance in MM. It has been observed that there is an increased expression of Mcl-1 in 52% of patients with MM during diagnosis, …

A Preliminary Report On The Role Of Lipoxin A4 In Reinstating The Blood-Brain Barrier Integrity In A Rodent Model Of Acute Inflammation With Impaired Cerebrovasculature, Minjal Patel, Shruti Varshney, Ananya Nethikunta, George G. Godsey, Mary C. Kosciuk, Ana Rodriguez, Bernd Spur, Kingsley Yin, Randel L. Swanson, Venkat Venkataraman, Robert G. Nagele, Nimish Acharya

Rowan-Virtua Research Day

Background: The blood-brain barrier (BBB) is responsible for maintaining brain homeostasis and ultimately proper neuronal function. Disruption of the BBB, leading to increased BBB permeability, has been reported in several neurodegenerative diseases, including Alzheimer’s disease (AD) and traumatic brain injury (TBI). Lipoxins (LXs) are a class of arachidonate-derived eicosanoids, which are a class of specialized pro-resolving lipid mediators (SPMs). SPMs are known to inhibit immune response through inhibition of cellular infiltration, downregulation of pro-inflammatory mediators and upregulation of anti-inflammatory mediators. Hence, LXs are recognized as “breaking signals” in the inflammatory process. One form of LXs, Lipoxin A4 (LXA4) …

The Role Of Med13 In Proteaphagy, John Sauer, Brittany Friedson, Katrina Cooper

Rowan-Virtua Research Day

Regulation of proteasomes is important for adaptation to cellular stress. Previous studies have shown that following starvation stress, proteasomes are targeted for destruction by autophagy. However, how cells control proteasomes in response to nitrogen starvation remains unclear. This study delves into the intricate interplay between Med13, proteaphagy, and stress response regulation, aiming to elucidate their roles in cellular survival mechanisms. It focused on the highly conserved Cdk8 kinase module (CKM) of the Mediator complex a that plays a pivotal involvement in cellular signaling and gene regulation under stress conditions. During the investigation, we asked if the degradation of specific proteasome …

Trna Anticodon Cleavage By Target-Activated Crispr-Cas13a Effector, Ishita Jain, Matvey Kolesnik, Konstantin Kuznedelov, Leonid Minakhin, Natalia Morozova, Anna Shiriaeva, Alexandr Kirillov, Sofia Medvedeva, Alexei Livenskyi, Laura Kazieva, Kira S Makarova, Eugene V Koonin, Sergei Borukhov, Konstantin Severinov, Ekaterina Semenova

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Type VI CRISPR-Cas systems are among the few CRISPR varieties that target exclusively RNA. The CRISPR RNA–guided, sequence-specific binding of target RNAs, such as phage transcripts, activates the type VI effector, Cas13. Once activated, Cas13 causes collateral RNA cleavage, which induces bacterial cell dormancy, thus protecting the host population from the phage spread. We show here that the principal form of collateral RNA degradation elicited by Leptotrichia shahii Cas13a expressed in Escherichia coli cells is the cleavage of anticodons in a subset of transfer RNAs (tRNAs) with uridine-rich anticodons. This tRNA cleavage is accompanied by inhibition of protein synthesis, thus …

Ksp1 Is An Autophagic Receptor Protein For The Snx4-Assisted Autophagy Of Ssn2/Med13, Sara E Hanley, Stephen D Willis, Steven J Doyle, Randy Strich, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Ksp1 is a casein II-like kinase whose activity prevents aberrant macroautophagy/autophagy induction in nutrient-rich conditions in yeast. Here, we describe a kinase-independent role of Ksp1 as a novel autophagic receptor protein for Ssn2/Med13, a known cargo of Snx4-assisted autophagy of transcription factors. In this pathway, a subset of conserved transcriptional regulators, Ssn2/Med13, Rim15, and Msn2, are selectively targeted for vacuolar proteolysis following nitrogen starvation, assisted by the sorting nexin heterodimer Snx4-Atg20. Here we show that phagophores also engulf Ksp1 alongside its cargo for vacuolar proteolysis. Ksp1 directly associates with Atg8 following nitrogen starvation at the interface of an Atg8-family interacting …

Profiling And Verifying The Substrates Of E3 Ubiquitin Ligase Rsp5 In Yeast Cells, Shuai Fang, Geng Chen, Yiyang Wang, Rakhee Ganti, Tatiana A Chernova, Li Zhou, Savannah E Jacobs, Duc Duong, Hiroaki Kiyokawa, Yury O Chernoff, Ming Li, Natalia Shcherbik, Bo Zhao, Jun Yin

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Yeast is an essential model organism for studying protein ubiquitination pathways; however, identifying the direct substrates of E3 in the cell presents a challenge. Here, we present a protocol for using the orthogonal ubiquitin transfer (OUT) cascade to profile the substrate specificity of yeast E3 Rsp5. We describe steps for OUT profiling, proteomics analysis, in vitro and in cell ubiquitination, and stability assay. The protocol can be adapted for identifying and verifying the ubiquitination targets of other E3s in yeast. For complete details on the use and execution of this protocol, please refer to Wang et al.

Modeling Biphasic, Non-Sigmoidal Dose-Response Relationships: Comparison Of Brain- Cousens And Cedergreen Models For A Biochemical Dataset, Venkat D. Abbaraju, Tamaraty L. Robinson, Brian P. Weiser

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Biphasic, non-sigmoidal dose-response relationships are frequently observed in biochemistry and pharmacology, but they are not always analyzed with appropriate statistical methods. Here, we examine curve fitting methods for “hormetic” dose-response relationships where low and high doses of an effector produce opposite responses. We provide the full dataset used for modeling, and we provide the code for analyzing the dataset in SAS using two established mathematical models of hormesis, the Brain-Cousens model and the Cedergreen model. We show how to obtain and interpret curve parameters such as the ED50 that arise from modeling, and we discuss how curve parameters might change …

Effects Of Sex And Estrous Cycle On Intravenous Oxycodone Self-Administration And The Reinstatement Of Oxycodone-Seeking Behavior In Rats, Nicole M. Hinds, Ireneusz D. Wojtas, Corinne A. Gallagher, Claire M. Corbett, Daniel F. Manvich

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The increasing misuse of both prescription and illicit opioids has culminated in a national healthcare crisis in the United States. Oxycodone is among the most widely prescribed and misused opioid pain relievers and has been associated with a high risk for transition to compulsive opioid use. Here, we sought to examine potential sex differences and estrous cycle-dependent effects on the reinforcing efficacy of oxycodone, as well as on stress-induced or cue-induced oxycodone-seeking behavior, using intravenous (IV) oxycodone self-administration and reinstatement procedures. In experiment 1, adult male and female Long-Evans rats were trained to self-administer 0.03 mg/kg/inf oxycodone according to a …

Invited Review: Adrenocortical Function In Avian And Non-Avian Reptiles: Insights From Dispersed Adrenocortical Cells., Rocco V. Carsia, Patrick J. Mcilroy, Henry B John-Alder

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Herein we review our work involving dispersed adrenocortical cells from several lizard species: the Eastern Fence Lizard (Sceloporus undulatus), Yarrow's Spiny Lizard (Sceloporus jarrovii), Striped Plateau Lizard (Sceloporus virgatus) and the Yucatán Banded Gecko (Coleonyx elegans). Early work demonstrated changes in steroidogenic function of adrenocortical cells derived from adult S. undulatus associated with seasonal interactions with sex. However, new information suggests that both sexes operate within the same steroidogenic budget over season. The observed sex effect was further explored in orchiectomized and ovariectomized lizards, some supported with exogenous testosterone. Overall, a suppressive effect of testosterone was evident, especially in cells …

Role Of Chronic Stress-Induced Neuroinflammation In Rodent Locus Coeruleus Physiology And Anxiety-Like Behaviors, Arthur Anthony Alfonso Reyes

Graduate School of Biomedical Sciences Theses and Dissertations

The locus coeruleus (LC), the primary site of brain norepinephrine (NE), is a key anatomical brain region implicated in the stress response. Stress is a neuroendocrine physiologic response to a stressor that promotes organism survival through adaptive change and restoration of homeostasis. The central stress response, which drives behavioral and physiological change, is primarily mediated by activating the hypothalamic-pituitary-adrenal (HPA) axis. While advantageous in the short term, chronic stress exposure can lead to HPA axis and LC dysregulation, which are thought to contribute to the etiology of anxiety disorders. Previous studies demonstrate the effects of acute stress in increasing LC …

Differential Degeneration Of Neurons In A Mouse Model Of Canavan Disease, Vibha Chauhan, Quy Nguyen, Jeremy Francis, Paola Leone

Rowan-Virtua Research Day

Canavan disease (CD) is an inherited leukodystrophy caused by inactivating mutations to the glial enzyme aspartoacylase (ASPA). ASPA catabolizes neuronal N-acetylaspartate (NAA) into free acetate and aspartate and loss of this function results in the chronic elevation of non-catabolized NAA and the failure of developmental myelination. Elevated NAA is thought to cause damage to myelin and myelin-producing cells (oligodendrocytes, but the viability of neurons in CD is relatively unexplored. We compare here the progressive degeneration of neurons in two regions of the CD mouse brain, the thalamus and the cortex, distinguished by differing degrees of vacuolation, and show that the …

The Involvement Of Ubiquitin In Med13 Cyclin C Degradation Following Cellular Stress, Ayesha Gurnani, Brittany Friedson, Katrina Cooper

Rowan-Virtua Research Day

The Cdk8 Kinase Module is a dissociable regulator of cellular stress response genes, with degradation of its components Med13 and cyclin C eventually determining cell fate decisions such as engaging cell survival or cell death mechanisms. We aimed to explore the roles of ubiquitin in degradation of the Cdk8 Kinase Module following nitrogen starvation, with respect to the potential involvement of deubiquitinating enzyme Doa4, lysine linkage at position K63, and E2 ubiquitin conjugating enzymes Ubc4 and Ubc5. We utilized Western blot analysis to observe nitrogen starvation-induced degradation of Med13-HA in wild-type, doa4 mutant, and K63R yeast strains; degradation of cyclin …

Comparative Analysis Of The Effects Of Actual Versus Assumed Opioid Experience On The Regulation Of Ventral Striatal Opioid Receptor Gene Expression, Indu Mithra Madhuranthakam, Martin Job

Rowan-Virtua Research Day

Rationale: We conducted experiments to assess the effect of prior opioid experience on gene expression changes. We compared the current experimenter-imposed short versus extended-access conditions of opioid self-administration and developed a new quantitative method to determine their effectiveness in identifying the role of opioid experience in regulating opioid receptor expression levels in the ventral striatum (VS) using an oxycodone self-administration/abstinence model.

Methods: In this study, male Sprague-Dawley rats (n=36) were trained for 20 days to self-administer oxycodone at 0.1 mg/kg/infusion under short access (n=15, or saline as controls n=3, for 3h/day) or extended access (n=15, or saline as controls n=3, …

Identifying Co-Factors That Drive Tra-1 Activator Function, Jibran Imtiaz, Yongquan Shen, Ronald Ellis

Rowan-Virtua Research Day

Gli proteins are involved in cell fate determination, proliferation, and patterning in many species and are major effectors of Hedgehog (Hh) signaling. There are three Gli proteins in humans, and mutations or errors in their regulation lead to a variety of developmental disorders or cancer. However, the mechanisms by which they interact with co-factors are poorly understood. We are analyzing co-factors of Gli proteins using TRA-1 in Caenorhabditis nematodes. The TRA-1 zinc fingers are structurally like those of other Gli proteins, and TRA-1 can be cleaved like other Gli proteins to form a repressor. However, its function has changed during …

Swallowing Disrupts Tongue-Jaw Coordination During Chewing In A Rat Model Of Parkinson's Disease, Meejan Palhang, N. Charles, Francois Gould

Rowan-Virtua Research Day

The primary motor symptoms of Parkinson’s disease, including bradykinesia, rigidity, and tremor, are associated with difficulties regulating transitions between motor behaviors due to basal ganglia dysfunction. Chewing and swallowing, which are disordered in most patients with Parkinson’s disease, are two complex motor behaviors which overlap in time and share some neuromuscular components. The objective of this study is to identify how Parkinson’s disease affects the coordination of chewing and swallowing. We hypothesize that as a result of impaired regulation of shift between motor patterns, chewing cycles that occur with a swallow will be more affected that chewing cycles occurring in …

Research Personnel Exposure To Carbon Dioxide During Euthanasia Procedures, Devon Nealer, Felicia Reibstein, Jennifer Bendorf, Emily Lafferty, Stephanie Ramborger, Taylor Swift, Jacqueline O'Malley, Thomas Boyle

Rowan-Virtua Research Day

Carbon dioxide (CO2) is a commonly used euthanasia agent in animal facilities. This procedure is carried out by replacing oxygen with carbon dioxide in animal cages, thus providing a quick and painless method of euthanasia. Unfortunately, there has been limited research on the potential effects of human exposure to CO2 during euthanasia procedures.

Following a previous carbon dioxide exposure study in the vivarium at Rowan SOM in 2016, the CO2 cylinders and euthanasia chambers have been relocated to room 153 Science Center and the vivarium has adopted a localized exhaust that helps remove the contaminant at the source.

While the …

Orthologs Of The C. Elegans Heterochronic Genes Have Divergent Functions In C. Briggsae, Maria Ivanova, Eric G. Moss

Rowan-Virtua Research Day

The heterochronic genes of C. elegans comprise the best-studied pathway controlling the timing of tissue and organ formation in an animal. To begin to understand the evolution of this pathway, the significance of each factor, and the relationships among the components, we characterized 11 C. briggsae orthologs of C. elegans heterochronic genes. Using CRISPR/Cas9, we made a variety of alleles and found that several mutant phenotypes differ in significant ways from those of C. elegans. Although most orthologs displayed defects in developmental timing, those phenotypes could differ in which stages they controlled, the penetrance and expressivity of the phenotypes, or …

Extravasated Brain-Reactive Autoantibodies Perturb Neuronal Surface Protein Expression In Alzheimer's Pathology, Wardah Bajwa, Mary Kosciuk, Randel L. Swanson, Anuradha Krishnan, Venkat Venkataraman, Robert Nagele, Nimish Acharya

Rowan-Virtua Research Day

Background: Increased blood-brain barrier (BBB) permeability is reported in both the neuropathological and in vivo studies in both Alzheimer’s Disease (AD) and age matched cognitively normal, no cognitive impairment (NCI), subjects. Impaired BBB allows various vascular components such as immunoglobulin G (IgG) to extravasate into the brain and specifically bind to various neuronal surface proteins (NSP), also known as brain reactive autoantibodies (BrABs). This interaction is predicted to further enhance deposition of amyloid plaques.

Hypothesis: Interaction between extravasated BrABs and its cognate NSPs lower the expression of that NSPs in AD patients.

Methods: We selected Western blotting technique to study …

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …

The Effects Of Specialized Pro-Resolving Mediator Lipoxin A4 On Pseudomonas Aeruginosa Biofilms And Interactions With Monocytes, Julianne M. Thornton

Graduate School of Biomedical Sciences Theses and Dissertations

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen known as a major cause of hospital-acquired secondary infections, commonly causing chronic respiratory infections in immunocompromised individuals, especially those with cystic fibrosis, and often found in wound infections. P. aeruginosa uses the quorum sensing pathway to readily form protective biofilms, which reduce the efficacy of antibiotics and access by host immune cells to eradicate the pathogen. Specialized pro-resolving mediators (SPMs) are lipids endogenously produced by the host immune response to infection to aid in infection resolution. One SPM, Lipoxin A4 (LxA4), has been shown to be a robust quorum sensing inhibitor.

The …

Modeling The Tripartite Role Of Cyclin C In Cellular Stress Response Coordination, Steven J. Doyle

Graduate School of Biomedical Sciences Theses and Dissertations

For normal cellular function, exogenous signals must be interpreted and careful coordination must take place to ensure desired fates are achieved. Mitochondria are key regulatory nodes of cellular fate, undergoing fission/fusion cycles depending on the needs of the cell, and help mediate cell death fates. The CKM or Cdk8 kinase module, is composed of cyclin C (CC), Cdk8, Med12/12L, and Med13/13L. The CKM controls RNA polymerase II, acting as a regulator of stress-response and growth-control genes. Following stress, CC translocates to the mitochondria and interacts with both fission and iRCD apoptotic mediators. We hypothesize that CC represents a key mediator, …

Investigating The Antibacterial And Immunomodulatory Properties Of Lactobacillus Acidophilus Postbiotics, Rachael M. Wilson

Graduate School of Biomedical Sciences Theses and Dissertations

Probiotics are nonpathogenic microorganisms that have been extensively studied for their ability to prevent various infectious, gastrointestinal, and autoimmune diseases. The mechanisms underlying these probiotic effects have not been elucidated. However, we and other researchers have evidence suggesting that probiotic bacteria secrete metabolites that are antimicrobial and anti-inflammatory. As such, we developed a methodology to collect the secreted metabolites from a probiotic bacterium, Lactobacillus acidophilus, and tested this cell free filtrate (CFF) both in vitro and in vivo. Using this CFF, we have demonstrated that L. acidophilus secretes a molecule(s) that has specific bactericidal activity against the opportunistic pathogen, Pseudomonas …