Life Sciences Commons^™

The Secretory Pathway Calcium Atpase 2c Promotes Increased Cytosolic Calcium Levels, Melissa Fenech

Electronic Thesis and Dissertation Repository

Pancreatic acinar cell exocytosis requires precise calcium (Ca²⁺) signals. When cytosolic Ca²⁺ levels remain high, cellular functions are disrupted, which is associated with initiation of pancreatitis. Ca²⁺ signals are achieved through regulating endoplasmic reticulum (ER) stores, Ca²⁺ATPases, and store-operated Ca²⁺ entry (SOCE). However, how these pathways interact to create precise signals is not well understood. In a pancreatic model of dysregulated Ca²⁺ homeostasis, secretory pathway Ca²⁺ATPase 2 (SPCA2) expression is significantly decreased. In the pancreas, only a C-terminally truncated form of SPCA2 (termed SPAC2C) exists. Recent studies indicate a role …

The Identification Of Long Non-Coding Rna Zfas1 Through An Exploratory Rna-Sequencing Analysis And Its Association With Epithelial-To-Mesenchymal Transition In Colon Cancer Adenocarcinoma., Stephen J. O'Brien

Electronic Theses and Dissertations

Colorectal adenocarcinoma is the fourth most common cancer diagnosed worldwide and is a significant cause of morbidity and mortality. This dissertation performed an exploratory RNA-sequencing analysis comparing gene expression between colon adenocarcinoma tissue and paired normal colon epithelium. After identification of a number of lncRNAs that were increased in expression in colon adenocarcinoma compared to normal colon epithelium, we aimed to validate the expression and investigate their function in vitro. Specifically, we focused on the lncRNA ZFAS1 and its association with epithelial-to-mesenchymal transition. These studies found the following: 1. Seven candidate lncRNAs were identified from the exploratory RNA-sequencing analysis to …

The Role Of Adaptive Immunity In Chronic Hypoxia-Induced Pulmonary Hypertension, Levi David Maston

Biomedical Sciences ETDs

Inflammation is a prominent pathologic feature in pulmonary arterial hypertension as demonstrated by pulmonary vascular infiltration of inflammatory cells, including T and B lymphocytes. However, the contribution of the adaptive immune system is not well characterized in pulmonary hypertension (PH) caused by chronic hypoxia (CH). Inflammatory cells, through various mechanisms, have the capability to increase pulmonary vascular resistance in various disease states. CD4⁺T cells have the potential to play a significant role in the disease process initiated by hypoxia. CD4⁺T cells are largely responsible for orchestrating downstream immune processes and are critical in focusing and amplifying …

The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger

Masters Theses

Intracellular acidosis is a putative agent of skeletal muscle fatigue, in part, because acidosis depresses the calcium (Ca²⁺) sensitivity and force production of muscle (18, 50). However, the molecular mechanisms behind this depression in Ca²⁺ sensitivity and force production are unknown. This gap in knowledge poses a significant challenge in generating a complete understanding of the fatigue process. To close this gap, the ability of myosin to bind to a single actin filament was measured under acidic conditions, in a laser trap assay, with and without regulatory proteins. Decreasing pH from 7.4 to 6.5 reduced the frequency …

Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello

Electronic Thesis and Dissertation Repository

Stromal-interaction molecule 2 (STIM2) is an endoplasmic reticulum (ER) membrane-inserted Ca²⁺-sensing protein which, together with the plasma membrane Ca²⁺ channel Orai1, regulates basal Ca²⁺ homeostasis and store-operated Ca²⁺ entry (SOCE). Recent evidence suggests that S-nitrosylation, which is the covalent attachment of a nitric oxide (NO) moiety to a cysteine thiol, can attenuate the function of the paralog STIM1 protein. Compared to STIM1, STIM2 also functions as a basal Ca²⁺ homeostatic feedback regulator. Therefore, the objective of my study was to evaluate the susceptibility of STIM2 to S-nitrosylation and the effects that this …

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …

Mapping And Functional Characterization Of Proteolytic Cleavage Of Murine Kidney Injury Molecule-1, Saranga Sriranganathan

Electronic Thesis and Dissertation Repository

Kidney injury molecule-1 (KIM-1) is a transmembrane glycoprotein expressed apically on proximal tubule epithelia during acute kidney injury (AKI). KIM-1, as a phagocytic receptor, facilitates clearance of apoptotic cells (efferocytosis) from tubular lumen, thereby reducing inflammation and promoting repair. Human KIM-1 undergoes spontaneous and accelerated ectodomain shedding into urine and blood via metalloproteases; tumour necrosis factor-a converting enzyme (TACE/ADAM17) and a disintegrin and metalloprotease 10 (ADAM10). Blood and urine KIM-1 are clinical AKI biomarkers, however, biological significance of KIM-1 shedding is unknown. To study this in vivo in mice, I first aimed to identify murine KIM-1 cleavage site and study …

The Effects Of Branched Chained Amino Acid Supplementation On Acute Markers Of Fatigue And Performance, Joseph Walters

Electronic Theses and Dissertations

The purposes of this dissertation were to investigate the acute effects of branched-chain amino acids on psychological, physiological, and subsequent performance changes following high volume resistance training. The rationale for this study design was based on abrupt or contiguous training/ competitions that specific athletes encounter in a competitive season. This study design also sought to fill some gaps in the scientific literature concerning the efficacy of BCAAs for subjective fatigue in a resistance training paradigm. To address the purposes of this dissertation, a one-week study was conducted on resistance trained males, in which half of the subjects were randomly selected …

Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) arise from perturbations in complex molecular and cellular processes underlying normal embryonic heart development. CHDs are the most common congenital malformation, occurring in 1 to 5% of live births, and are the leading cause of pediatric mortality. Adverse genetic and environmental factors can impede normal cardiogenesis and increase the likelihood of CHDs. Pregestational maternal diabetes increases the risk of CHDs in children by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. The aim of …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster

Masters Theses

Skeletal muscle fatigue is the contraction-induced decline in whole muscle force or power, and can be greater in older versus young adults. Fatigue primarily results from increased metabolism elevating phosphate (P_i) and hydrogen (H⁺), which alters myosin-actin interactions; however, which steps of the myosin-actin cross-bridge cycle are changed and their reversibility are unclear. PURPOSE: This study sought to: 1) Examine the effects of elevated P_i and H⁺ on molecular and cellular function, and 2) Test the ability of deoxyadenosine triphosphate (dATP), an alternative energy to adenosine triphosphate (ATP), to reverse the contractile changes induced …

Oleic Acid Attenuates Palmitic Acid-Induced Impairments In Mouse Blastocyst Development, Maisoon Dafalla Yousif

Electronic Thesis and Dissertation Repository

Palmitic acid (PA) and oleic acid (OA) are the most abundant saturated and monounsaturated non-esterified fatty acids, respectively, in serum. The consequences of PA and OA treatment on preimplantation mouse embryo development were investigated. It was hypothesized that OA treatment from the two-cell stage onwards would attenuate PA-induced reductions in mouse blastocyst development. PA significantly reduced development to the blastocyst stage. Transcript analysis revealed that PA increased ER stress pathway markers activating transcription factor 3 and C/EBP homologous protein transcripts, and XBP1 splicing. Co-culture of PA-treated embryos with OA prevented this PA-induced ER stress and rescued blastocyst development. Cytoplasmic lipid …

The Proteomic Response Of Northern Elephant Seal (Mirounga Angustirostris) Pups To Physiological Stress During Development, Melissa P. Voisinet

Master's Theses

Background: Northern elephant seals transition from terrestrial nursing pups to pelagic foraging juveniles in a short period of just 8-12 weeks. During the post-weaning period, pups rely solely on the energy reserves gained during nursing for their caloric demands and water supply. The prolonged absence of food after weaning is the first of many fasts for which the seals have evolved adaptations such as decreased urine production and increased blubber reserves. The stressors experienced from learning to dive for the first time are also stressors that they will experience frequently as an adult and for which they have evolved adaptations. …

Role Of Pkcbeta And Oxidant Signaling In Neonatal Pulmonary Hypertension, Joshua R. Sheak

Biomedical Sciences ETDs

Chronic hypoxia (CH)-induced vasoconstriction has been implicated in the pathogenesis of pulmonary hypertension (pHTN) in infants with chronic cardiorespiratory disorders. Although endothelial dysfunction, reduced nitric oxide (NO) bioavailability and oxidative stress contribute to a variety of cardiovascular disorders, their contribution to enhanced vasoconstrictor reactivity in neonatal pHTN is poorly understood. We therefore hypothesized that neonatal CH augments pulmonary vasoconstrictor reactivity by limiting NO-dependent pulmonary vasodilation and by promoting the generation of reactive oxygen species (ROS).

Enzymatic sources of ROS in the vasculature include NADPH oxidase isoforms, xanthine oxidase, and uncoupled endothelial nitric oxide synthase (eNOS). The mitochondria are also a …

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …

Comparative Plasma Proteomics In Muscle Atrophy Induced By Cancer Cachexia And Hindlimb Unloading, Kirsten Rene Dunlap

Graduate Theses and Dissertations

Introduction: Muscle atrophy results from a dysfunction in protein turnover that leads to loss of mass and function and occurs concurrently with multiple pathologies such as cancer and extended bed rest. Atrophy reduces overall quality of life while increasing morbidity and mortality. Currently, efficacious therapeutic interventions to treat and prevent muscle wasting in all its forms are lacking, however if conserved mechanisms can be identified between wasting conditions, this would aid in the development of multipurpose therapeutics to ameliorate this pathology. Purpose: To examine circulating factors present across atrophic pathologies. Methods: 35 male C57BL/6J mice were assigned to hindlimb unloading …

Predators Select For Higher Levels Of Brain Cell Proliferation In Trinidadian Killifish, Rivulus Hartii, Joshua Corbo

Senior Theses and Projects

Brain cell proliferation is an important form of brain plasticity that has been sparsely studied in natural populations. Killifish, Rivulus hartii, from the freshwater streams of Trinidad are a remarkable organism for understanding how brain plasticity is influenced by both internal and environmental factors. Through extensive ecological studies in the region, Trinidadian killifish have been used to determine how predation directly effects brain cell proliferation and brain size. In wild populations, waterfalls in the streams block predator movements upstream, thereby creating distinct populations of killifish – i.e., killifish living with abundant predators (high predators, HP) and killifish living with …

Quantitative Proteome Analysis Of Alfalfa In Drought Stress Under The Influence Of Mir156, Alpa Puri

Electronic Thesis and Dissertation Repository

Medicago sativa is one of the most produced perennial forage crops in Canada. Drought stress is a major form of abiotic stress affecting the productivity and annual yield of alfalfa. A small noncoding RNA, miR156 has a role in abiotic stress tolerance, while regulating downstream SPL genes. In this study, whole leaf proteome and amino acid concentrations of miR156OE (A8) genotype of alfalfa under drought stress were quantified. In results, 3,000 proteins groups were identified using MaxQuant when searched against Medicago truncatula protein sequence database. Gene ontology analysis showed enriched proteins were involved in biological and molecular processes such as …

The Effects Of A Ketone Body On Synaptic Transmission, Alexandra Elizabeth Stanback

Theses and Dissertations--Biology

The ketogenic diet is commonly used to control epilepsy, especially in cases when medications cannot. The diet typically consists of high fat, low carb, and adequate protein and produces a metabolite called acetoacetate. Seizure activity is characterized by glutamate excitotoxicity and therefore glutamate regulation is a point of research for control of these disorders. Acetoacetate is heavily implicated as the primary molecule responsible for decreasing glutamate in the synapse; it is believed that acetoacetate interferes with the transport of glutamate into the synaptic vesicles. The effects on synaptic transmission at glutamatergic synapses was studied in relation to the ketogenic diet …

Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs

UNF Graduate Theses and Dissertations

Previous research regarding aquatic acidification has examined the protonation of the carbonate and does not consider calcium to be a limiting factor. This is the first study to suggest that pH may affect the uptake of calcium in crustacean gills. This project describes ion transport mechanisms present in the cell membranes of white river shrimp Litopenaeus setiferus gill epithelium, and the effects of pH on the uptake of calcium by these means. Partially purified membrane vesicles (PPMV) of shrimp gills were prepared through a homogenization process that has been used previously to define ion transport in crab and lobster gill …

The Orexin System In Doca-Salt Hypertension: Regulation Of Vasopressin, Jeremy Bigalke

Dissertations, Master's Theses and Master's Reports

Orexin is a neuropeptide with a large range of functions, with a recently discovered role in blood pressure (BP) regulation. Although the role of brain orexin system in hypertension has been investigated in several hypertensive animals, it remains unclear whether activation of the orexin system contributes to the development of Deoxycorticosterone-acetate (DOCA) hypertension, an animal model of human salt sensitive hypertension. In this study, we investigated the hypothesis that Orexin-1 receptor (OX1R) expression is increased in the paraventricular nucleus (PVN), a critical brain area controlling cardiovascular function, which subsequently increases vasopressin (AVP) expression and peripheral secretion, resulting in hypertension development …

Effects Of Acute Hypoxia On Danio Rerio, Karly Crail

Williams Honors College, Honors Research Projects

The purpose of this research experiment was to determine the effects of acute hypoxia on the embryonic zebrafish (Danio rerio) cardiovascular system and assess the critical oxygen level at which embryonic function is compromised. This goal was achieved by exposing embryos to decreasing oxygen concentrations, (6.0 mg/L-0 mg/L) and observing the heart under an inverted microscope. Data analysis was conducted to determine end systolic volume, end diastolic volume, stroke volume, heart rate, and cardiac output. It was hypothesized that hypoxia would stimulate cardiac activity, because in early developmental stages, tissues are supplied with oxygen through bulk diffusion, and …

Norepinephrine Induces Macrophage Polarization Critical To Eliciting Renal Fibrogenesis, Hannah Manoj

Undergraduate Research Symposium Posters

Renal denervation before ischemic injury has been shown to protect against fibrogenesis and the inflammatory response, which are two causes for the progression of chronic kidney disease. However, the administration of norepinephrine (NE) to denervated renal systems induced fibrogenesis and inflammation after ischemic injury. Our previous data indicates that NE-mediated stimulation of the α2-AR receptors is responsible for regulating several of the processes implicated in fibrogenesis and inflammation, including the accumulation, migration, and infiltration of macrophages to the site of injury; this is especially relevant as macrophages have been implicated as one potential cause for the inflammatory response.

Recent studies, …

Electrostatic Networks And Mechanisms Of Δph-Dependent Gating In The Human Voltage-Gated Proton Channel Hv1, Ashley L. Bennett

Theses and Dissertations

The structure of the voltage-gated proton (H⁺) channel Hv1 is homologous to the voltage sensor domain (VSD) of tetrameric voltage-gated Na⁺, K⁺ and Ca²⁺ channels (VGCs), but lacks a pore domain and instead forms a homodimer. Similar to other VSD proteins, Hv1 is gated by changes in membrane potential (V), but unlike VGCs, voltage-dependent gating in Hv1 is modulated by changes in the transmembrane pH gradient (DpH = pH_o - pH_i). In Hv1, pH_o or pH_i changes shift the open probability (P_OPEN)-V relation by ~40 mV per …

Quantification Of Aqp11 Paralog Expression In The Osmoregulatory Organs Of Anguilla Rostrata, Keith C. Kurt

Electronic Theses and Dissertations

Osmoregulation is facilitated by using an assortment of ion and water channels to assist acclimation to changing conditions and to maintain cellular homeostasis. Euryhaline fish can be found in both seawater and freshwater (SW and FW) environments. Expression of ion and water channels have been experimentally demonstrated to change as a fish acclimates to different environmental conditions. Relatively recently, a new group of water channels has been discovered that are primarily intracellular and includes aquaporin 11 (AQP11). Typically, AQPs are located on the cell plasma membrane to allow water to flow in and out of the cell by osmosis to …

An Evaluation Of Induced Shear Stress On Endothelial Cellular Adhesion Molecules, Edward B. Crabb

Theses and Dissertations

The pathophysiology of atherosclerotic cardiovascular disease (CVD) is highlighted by vascular dysfunction and low-grade vascular inflammation. Furthermore, the site-specific distribution of atherosclerosis throughout the arterial vasculature is primarily determined by local hemodynamic force. Therefore, this dissertation outlines three experiments designed to investigate the role of acute mental and physical (i.e., aerobic exercise), and vascular wall shear stress (SS) on the inflammatory aspects of atherosclerosis. Chapter 2 examines the effect of acute laboratory-induced mental stress on intracellular pro-inflammatory signaling pathways in peripheral blood mononuclear cells. Chapter 3 investigates the impact of acute laboratory-induced mental stress and maximal aerobic exercise on the …

Embryonic Stem Cell-Derived Exosomes Increase The Antiproliferative Activity Of Doxorubicin In Breast Cancer, Alexander M. Hirsch

Theses and Dissertations

The field of cancer research has grown immensely in recent decades and has led to a better understanding of the causes of the disease, as well as greatly improved treatment for various types of cancers, especially breast cancer. One of the most effective treatments involves the chemotherapeutic drug doxorubicin (DOX). DOX is an effective tool against all types of breast cancer, especially against triple negative breast cancer. However, DOX causes adverse side effects that include damage to the heart and skeletal muscle, particularly above specific cumulative doses. Recent evidence suggests that embryonic stem cell-derived (ES) exosomes, nanoscale extracellular vesicles that …