Medicine and Health Sciences Commons^™

Gut Microbial Metabolite Indole: A Stimulator Of Enteroendocrine Cell Differentiation Via Activation Of Aryl Hydrocarbon Receptor, James Hart

Theses, Dissertations and Capstones

Enteroendocrine cells (EECs) regulate energy balance and glucose homeostasis by releasing hormones in response to food intake. Dysregulated EEC differentiation is observed in obesity, while gut microbiota metabolites influence this process. Here, we investigated the role of indole, a biologically active gut microbial metabolite, in EEC differentiation through aryl hydrocarbon receptor (AhR) activation. Human intestinal organoids derived from jejunal mucosal biopsies were exposed to indole. Indole treatment significantly increased mRNA levels of chromogranin A, an EEC marker. The effect was reversed by an AhR antagonist, indicating AhR involvement. Indole also upregulated AhR target gene mRNA levels. These findings highlight the …

Examining The Effects Of Exercise-Induced, Physical Stress Overtraining On Stress Biomarkers In Adolescent, C57bl/6 Mice, Curtis Scotty Davis

Theses, Dissertations and Capstones

Exercise has long been established as a therapeutic modality to improve health and related physical fitness, sports performance, and injury/risk reduction in both adults and adolescents (Haff & Triplett, 2015; Kaminsky, 2010). Nonetheless, there is a lack of research investigating the negative effects of exercise overstress (i.e., overtraining syndrome) in these populations, particularly adolescents (Brenner & American Academy of Pediatrics Council on Sports Medicine and Fitness, 2007; Matos & Winsley, 2007). The objective of this study was to examine hormone biochemical markers, anthropometric markers, and behavioral traits, which are associated with overtraining syndrome, in adolescent C57BL/6 mice. A total of …

Investigation Of The Effects Of Prenatal Drug Exposure On Astrocyte-Mediated Synaptogenic Signaling, Taylor Christian Boggess

Theses, Dissertations and Capstones

One of the most significant outcomes of the rise in rates of opioid abuse in the United States has been a dramatic increase in the incidence of neonatal abstinence syndrome (NAS), the clinical diagnosis for the collection of withdrawal-like signs and symptoms commonly observed in the newborns of mothers who abused certain drugs, such as opioids, during pregnancy. While a great deal of research has investigated the short-term symptoms and potential treatments for NAS, including my own studies to identify emerging trends among a local population of NAS patients, there remains a critical need to investigate the long-term effects of …

Where Epigenetics Meets Food Intake: Their Interaction In The Development/Severity Of Gout And Therapeutic Perspectives, Philippe T. Georgel, Philippe Georgel

Biological Sciences Faculty Research

Gout is the most frequent form of inflammatory arthritis in the world. Its prevalence is particularly elevated in specific geographical areas such as in the Oceania/Pacific region and is rising in the US, Europe, and Asia. Gout is a severe and painful disease, in which co-morbidities are responsible for a significant reduction in life expectancy. However, gout patients remain ostracized because the disease is still considered “self-inflicted”, as a result of unhealthy lifestyle and excessive food and alcohol intake. While the etiology of gout flares is clearly associated with the presence of monosodium urate (MSU) crystal deposits, several major questions …

The Effects Of Concussion On Quantity Of Sleep And Quality Of Sleep, Taren Asheton Bone

Theses, Dissertations and Capstones

This study observed how a concussion's effects change the quantity and quality of sleep in collegiate athletes. There is a lack of research pertaining to this topic, explicitly involving collegiate athletes and the changes in sleep outcomes during concussion recovery from a concussion. The study design is a convenient cohort in the field involving athletes from two local universities. Participants wore a Readiband™ device for seven to ten days or throughout their concussion recovery. There were differences in total minutes in bed and calculated minutes in bed between concussed and non-concussed participants. This study indicates that concussion affects the quantity …

Crippling Rapid Evolution Of Metastasis And Drug Resistance In A549 Non-Small Cell Lung Cancer Cells With The Clinically Relevant Hsp90 Inhibitor Auy922, Nickolas Anthony Bacon

Theses, Dissertations and Capstones

The ability for species to evolve new features in response to changing circumstances in order to survive and propagate is a ubiquitous observation on both the macroscopic and microscopic levels of living systems. It should be no surprise, then, that diseases such as cancer utilize their own forms of adaptation to perpetuate themselves when exposed to external threats. Indeed, concepts drawn from Darwinian evolution are now widely accepted to help explain certain aspects of carcinogenesis and malignant progression, the sum of which have come to be known as the theory of tumor evolution. Since metastasis and drug resistance are features …

Role Of Na/K-Atpase Non-Enzymatic Signaling In Renal Proximal Tubule Sodium Transport, Shreya Tapan Mukherji

Theses, Dissertations and Capstones

The renal proximal tubule (RPT) is the center stage for renal handling of Na+ , a potent determinant of systemic Na+ and volume homeostasis in health and disease. In the RPT, through its classic ion-pumping function, Na + /K+ -ATPase (NKA) generates the Na+ gradient that drives apical Na+ absorption, mostly through Na+ /H+ exchanger (NHE3). In contrast, pharmacological evidence suggests that the activation of the NKA non-enzymatic signaling function, through Src and other signaling partners, triggers a cellular redistribution of NKA and NHE3 that decreases transcellular Na+ flux in cultured RPT cells. However, the physiological relevance of the nonenzymatic …

Na/K-Atpase Alphα1 Regulates Adipogenesis Via Its Conserved Caveolin Binding Motif, Minqi Huang

Theses, Dissertations and Capstones

The Na/K-ATPase (NKA) was identified in 1957 by Dr. Jens C. Skou. It belongs to the P-type ATPase family, which can actively transport ions across cell membranes by using the energy from adenosine triphosphate (ATP) hydrolysis. During the second half of the 20th century, the molecular mechanism of the NKA catalytic cycle was clarified, and the isoform diversity of NKA in different species and organs was identified. The active ion transport through NKA generates cell membrane ion gradients and the electric potential. Hence, the enzymatic function of NKA is critical for cell viability as well as multiple physiological processes including …

Potential Counter Regulatory Effects Of A Gut Microbiota Metabolite In Alleviating Down-Regulation Krüppel-Like Factor 4 In Intestinal Inflammation, Ylva Forslund

Theses, Dissertations and Capstones

Inflammatory bowel disease (IBD) is a medical condition characterized by chronic inflammation of the intestinal epithelium. Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, is vital for maintaining intestinal epithelial homeostasis. KLF4 promotes differentiation of goblet cells that generate the protective mucus layer. Reduced goblet cell number and defective mucus layer are associated with IBD. Shortchain fatty acids (SCFA) are known to play an important role in the maintenance of a strong and healthy intestinal epithelial layer and also in goblet cell differentiation. However, whether the positive effects of SCFAs on goblet cells are mediated, at least partly, via …

From Crib To Bench: Understanding Neonatal Opioid Withdrawal Syndrome (Nows) Using A Novel Rodent Model, Sarah Stevens

Theses, Dissertations and Capstones

As the opioid epidemic continues to grow, opioid use among pregnant women is increasing significantly. This has led to a steady rise in the number of infants born with neonatal opioid withdrawal syndrome (NOWS). Although short-term withdrawal symptoms associated with NOWS are well characterized, there are many gaps in our understanding of the short and long-term effects of prenatal opioid exposure. In CHAPTER 1, we describe the clinical presentation, associated neurodevelopmental challenges, and current treatments of NOWS. Our current understanding of the neuropathology of NOWS is limited, and therefore further research is needed. However, current animal models are limited by …

Targeting Epigenetic Mechanisms In Endometriosis, Sarah Elizabeth Brunty

Theses, Dissertations and Capstones

Endometriosis is a complex and elusive gynecological disease in which the inner lining of the uterus grows in locations outside of the uterus and forms lesions. It is known to affect 1 in 9 women of reproductive age worldwide. Symptoms of endometriosis include severe pain, heavy periods, and infertility. While multiple theories of origin exist, none fully encompass all aspects of the disease, although all theories agree that this is an inflammation-driven disease. Due to this, many researchers are turning towards epigenetics to explain the initiation and progression of endometriosis. However, what is causing these epigenetic changes is still a …

Musculoskeletal Injury In Reserve Officers' Training Corps: A Report From The Athletic Training Practice-Based Research Network, Kara N. Radzak, Joellen M. Sefton, Mark Timmons, Rachel Lopp, Christopher D. Stickley, Kenneth C. Lam

Kinesiology Faculty Research

Background: Reserve Officers’ Training Corps (ROTC) cadets must meet the same physical standards as active duty military servicemembers and undergo organized physical training (PT). ROTC participation, like all physical activity, can result in training-related musculoskeletal injury (MSKI), and of course, cadets could sustain MSKI outside of ROTC. However, MSKI incidence in ROTC programs is largely unknown.

Purpose: To describe patient and injury demographics of MSKI in 5 universities’ Army ROTC programs.

Study Design: Descriptive epidemiology study.

Methods: A retrospective chart review of electronic medical records was performed using the Athletic Training Practice-Based Research Network (AT-PBRN). Athletic trainers at 5 clinical …

Mechanisms Of Dopamine-Induced Methamphetamine Neurotoxicity, Melinda L. Asbury

Theses, Dissertations and Capstones

Methamphetamine (MA) neurotoxicity is particularly evident in the striatum where it causes extensive dopamine (DA) release and results in neurodegeneration. To identify specific signaling pathways and macromolecules involved in postsynaptic DA-induced striatal toxicity we used a SK-N-MC cell model that mimics postsynaptic D1 receptor-expressing striatal neurons. The cells were treated for 6-24 h with 0-50 µM DA. The concentration was chosen to impart physiological relevance to the study as it mirrors [DA] found within the striatum following MA exposure. We show that 25-50 µM DA resulted in protein changes consistent with nitro(oxidative) stress as well as enhanced cleavage of caspase …

Perceived Exertion And The Increase In Risk Of Injury In Rotc Cadets, Courtney D. Chiaramonte

Theses, Dissertations and Capstones

Context: Musculoskeletal injury in military personnel creates problems due to economic losses, and decreased training. The repetitive motions associated with military training and the daily physical training sessions can lead to the development of fatigue. Fatigue has been shown to contribute to 18% - 26% of musculoskeletal injuries. [7] Several studies have explored fatigue as a risk of injury during occupation. Fatigue has been shown to increase the perceived effort during physical exercise. The purpose of this study was to characterize the perception of effort during physical training sessions and injury rates in ROTC cadets throughout an academic year.

Methods …

The Anatomy Of The Carpal Tunnel And Hand Function Of Musicians, Emily Ann Lorenzen

Theses, Dissertations and Capstones

Musicians spend hours perfecting their trade, often leading to overuse injuries of the hand; of specific concern to musicians is carpal tunnel syndrome (CTS). This study evaluated the median nerve cross-sectional area and hand function of musicians and non-musicians. Patients completed the upper extremity and CTS specific function questionnaires. The median nerve cross-sectional area, and the width of the carpal tunnel were measured on ultrasound image. The median nerve cross-sectional area was greater in musicians than the non-musician group. The width of the carpal tunnel did not differ between the groups. Musicians showed higher levels of hand dysfunction than the …

Targeted Limb Heating Augments The Actions Of Igf1 In The Growth Plate And Increases Bone Elongation In Growing Mice, Holly Lyn Racine

Theses, Dissertations and Capstones

Bone elongation disorders can lead to painful musculoskeletal disabilities in adulthood. Existing treatment options to correct left-right asymmetry in limb length include invasive surgeries and/or drug regimens. These are often only partially effective. Previous studies in weanling mice have shown that a daily application of mild heat (40°C) to limbs on one side of the body could be used to noninvasively enhance bone elongation. However, the impact of heat-treatment on bone at the cellular level remains elusive. The epiphyseal growth plate, the band of cartilage located at each end of long bones, is the main site of longitudinal growth and …

Systematic Analysis Of Whole Exome Sequencing Determines Ret G691s Polymorphism As Germline Variant In Melanoma, Brent J. Smith Jr, Jennifer D. Hintzsche, Carol M. Amato, Aik-Choon Tan, Keith R. Wells, Allison J. Applegate, Rita T. Gonzalez, Jodie R. Barr, William A. Robinson

Marshall Journal of Medicine

Abstract

The RET proto-oncogene encodes a receptor tyrosine kinase that is activated by glial cell derived neutrotrophic factor (GDNF). Previous studies have found that a single nucleotide polymorphism (SNP), RETp (G691S), in the juxtamembrane domain enhances the signaling pathway and promotes tumor growth by GDNF in pancreatic and thyroid cancer in addition to melanoma. It is uncertain however whether this SNP is a germline variant or somatic mutation. A prior study reported that the RETp variant was a germline SNP in desmoplastic and non-desmoplastic melanomas. In the present study, we examined both melanoma tissue samples and matching peripheral blood DNA …

Tenofovir Induced Nephrotoxicity: A Mechanistic Study, Rachel A. Murphy

Theses, Dissertations and Capstones

Tenofovir (TFV) is a reverse transcriptase inhibitor that is approved by the United States Food and Drug Administration (FDA) to treat HIV and chronic Hepatitis B. It has a long half-life, allowing for once a day dosing and is effective in treatment of both naive and experienced patients. It is administered orally as tenofovir disoproxil fumarate (TDF) and is deesterified in plasma to the active drug TFV. However, renal impairment is associated with its use; TFV can induce decreased glomerular filtration rate (GFR) and free calcitriol, renal failure, and Fanconi Syndrome. The exact mechanism of toxicity currently remains unknown, largely …

The Effects Of Flexor Pronator Mass Fatigue On Medial Elbow Stability, Nathaniel Harvey Millard

Theses, Dissertations and Capstones

Introduction: The medial elbow is supported from valgus loading with the ulnar collateral ligament (UCL), the flexor pronator mass (FPM), and the radial head. Fatigue of muscle can lead to a decrease in force production. The decrease in force production can lead to a decrease in joint stability. This study tested the effect of fatigue of the FPM muscles on the width of the medial joint space.

Methods: Thirty-one participants volunteered for this study (18 female and 12 male, 1 excluded; mean height 170.2±10.1 cm, mean weight 71.2±15.6 kg, mean age 21.53±1.87 years old). Ultrasound images of the width of …

Vitamin K2 (Menaquinone) Supplementation And Its Benefits In Cardiovascular Disease, Osteoporosis, And Cancer, Grant S. Buchanan, Md, Thomas Melvin, Brandon Merritt, Charles Bishop, Md, Franklin D. Shuler, Md, Phd

Marshall Journal of Medicine

Vitamin K is known to play an essential role in the coagulation cascade; however, a growing body of research has found that a subtype of this vitamin, vitamin K₂ (menaquinone) may have a beneficial effect in osteoporosis, cardiovascular disease, and cancer. This purpose of this article is to provide a comprehensive review of recent literature regarding menaquinone and its role in human health. This review discusses the physiology of menaquinone, its clinical benefits in cardiovascular disease, osteoporosis, and cancer, and how it may interact with certain medications. The authors conclude that menaquinone supplementation has been shown to improve carboxylation …

Uncovering New Roles For The Aryl Hydrocarbon Receptor (Ahr) In Breast Cancer, Justin Kirk Tomblin

Theses, Dissertations and Capstones

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is responsive to many exogenous and endogenous ligands. AHR is of particular interest in cancer, and has been shown to play roles in tumor progression. As such, it has received growing attention as a possible chemotherapeutic target. Obesity increases the risk of breast cancer, complicates treatment of breast cancer, and stimulates the growth of larger, more aggressive mammary tumors. Many breast tumors in obese women are estrogen receptor (ER)-positive and, while targeting hormone receptors like ER is beneficial, many obese women see a recurrence of their cancer after standard …

Limited Trabecular Bone Density Heterogeneity In The Human Skeleton, Habiba Chirchir Phd

Biological Sciences Faculty Research

There is evidence for variation in trabecular bone density and volume within an individual skeleton, albeit in a few anatomical sites, which is partly dependent on mechanical loading. However, little is known regarding the basic variation in trabecular bone density throughout the skeleton in healthy human adults. This is because research on bone density has been confined to a few skeletal elements, which can be readily measured using available imaging technology particularly in clinical settings. This study comprehensively investigates the distribution of trabecular bone density within the human skeleton in nine skeletal sites (femur, proximal and distal tibia, third metatarsal, …

The Fossil Record Of Phenotypic Integration And Modularity: A Deep-Time Perspective On Developmental And Evolutionary Dynamics, Anjali Goswami, Wendy J. Binder, Julie Meachen, Robin O'Keefe

Biological Sciences Faculty Research

Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because …

Identification Of The Ps1 Thr147ile Variant In A Family With Very Early Onset Dementia And Expressive Aphasia, James Denvir, Shirley Neitch, Jun Fan, Richard M. Niles, Goran Boskovic, Bernard G. Schreurs, Donald A. Primerano, Daniel L. Alkon

Biochemistry and Microbiology

Background: Early onset dementias have variable clinical presentations and are often difficult to diagnose. We established a family pedigree that demonstrated consistent recurrence of very early onset dementia in successive generations.

Objective and Method: In order to refine the diagnosis in this family, we sequenced the exomes of two affected family members and relied on discrete filtering to identify disease genes and the corresponding causal variants.

Results: Among the 720 nonsynonymous single nucleotide polymorphisms (SNPs) shared by two affected members, we found a C to T transition that gives rise to a Thr147Ile missense substitution in the presenilin 1 (PS1) …

Epigenetic Role Of Ptip In Mouse Spermatogenesis, Chengjing Liu

Theses, Dissertations and Capstones

In mammals, spermatogenesis is a biological process inside the testis to produce spermatozoa from spermatogonia. This process is governed by both genetic and epigenetic mechanisms and thus is a powerful system for epigenetic research. Methylation of histone 3 lysine 4 (H3K4) is an epigenetic mark, which has been found to be dynamically modulated in mouse male germ cells during spermatogenesis. Pax2 Transactivation domain Interaction Protein (PTIP) has been recently identified as part of a H3K4 methyltransferase complex. In this study, I hypothesize that PTIP is an essential epigenetic regulator in mouse spermatogenesis. To test this hypothesis, I first established a …

Cerium Oxide Nanoparticles Attenuate Polymicrobial Sepsis Induced Splenic Damage In Male Sprague Dawley Rats, Venkata Vinay Kumar Bandarupalli

Theses, Dissertations and Capstones

Sepsis is a serious life threatening medical emergency which, if not treated properly, oftentimes results in organ failure and death. Current sepsis treatment protocols are largely centered on the use of antibiotics and supportive care. Recent studies have suggested that antibiotics fail to be effective for sepsis treatment when administered during hypo-dynamic phase of sepsis that is usually characterized by the presence of a cytokine storm. As such, there is an urgent need to develop novel therapeutic drugs that target the inflammatory cytokines that are secreted as a result of increased reactive oxygen species. Cerium oxide nanoparticles (CeO2) have been …

Chmp1 Negatively Regulates Epidermal Growth Factor Signaling In The Drosophila Wing, Meagan Elisabeth Valentine

Theses, Dissertations and Capstones

A critical step in cellular signaling through transmembrane receptors is the down-regulation of activated receptors through the multivesicular body (MVB) pathway to the lysosome. MVB generation is mediated by the highly conserved ESCRT (0, I, II, and III) protein complexes. Though the ESCRT-III complex provides the core function of the ESCRT machinery, it is the least characterized of the ESCRT complexes. The Chmp1 protein is an ESCRT-III component and a putative tumor suppressor that has been linked to pancreatic and renal cancers in humans. However, published data on Chmp1 activity are conflicting and its role during tissue development is not …

Examination Of Two Hydration Protocols During Simulated Forced Marching Under Acute Heat Stress, David Alan Cottrill

Theses, Dissertations and Capstones

The purpose of this study was to identify and compare the effects of ingesting either water or 6% solution of carbohydrates, electrolytes, and water on hydration status during simulated military road marching in hot environmental conditions. Five volunteer male subjects completed two 60 minute experimental trials exercising at a high intensity (RER .90-.95) in an improvised environmental chamber (29.7 ^{_{+ or -}} .18^oC, 11.3 + or - 2.13% relative humidity) in full army combat uniform carrying 18.18kg of equipment. Random assignment of either water or solution was completed prior to trial 1, and consumption of the unselected protocol …

Involvement Of Reactive Oxygen Species In A Feed-Forward Mechanism Of Na/K-Atpase Mediated Signaling, Yanling Yan, Anna P. Shapiro, Steven Haller, Vinal Katragadda, Lijun Liu, Jiang Tian, Venkatesha Basrur, Deepak Malhotra, Zi-Jian Xie, Nader G. Abraham, Joseph I. Shapiro Md, Jiang Liu

Biochemistry and Microbiology

Cardiotonic steroids (such as ouabain) signaling through Na/K-ATPase regulate sodium reabsorption in the renal proximal tubule. We report here that reactive oxygen species are required to initiate ouabain-stimulated Na/K-ATPase·c-Src signaling. Pretreatment with the antioxidant N-acetyl-L-cysteine prevented ouabain-stimulated Na/K-ATPase·c-Src signaling, protein carbonylation, redistribution of Na/K-ATPase and sodium/proton exchanger isoform 3, and inhibition of active transepithelial ²²Na⁺ transport. Disruption of the Na/K-ATPase·c-Src signaling complex attenuated ouabain-stimulated protein carbonylation. Ouabain-stimulated protein carbonylation is reversed after removal of ouabain, and this reversibility is largely independent of de novo protein synthesis and degradation by either the lysosome or the proteasome pathways. Furthermore, …

Evidence For Sigma Factor Competition In The Regulation Of Alginate Production By Pseudomonas Aeruginosa, Yeshi Yin, T. Ryan Withers, Xin Wang, Hongwei D. Yu

Biochemistry and Microbiology

Alginate overproduction, or mucoidy, plays an important role in the pathogenesis of P. aeruginosa lung infection in cystic fibrosis (CF). Mucoid strains with mucA mutations predominantly populate in chronically-infected patients. However, the mucoid strains can revert to nonmucoidy in vitro through suppressor mutations. We screened a mariner transposon library using CF149, a non-mucoid clinical isolate with a misssense mutation in algU(AlgU^A61V). The wild type AlgU is a stress-related sigma factor that activates transcription of alginate biosynthesis. Three mucoid mutants were identified with transposon insertions that caused 1) an overexpression of AlgU^A61V, 2) an overexpression of …