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Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Medical Sciences

Theses/Dissertations

2019

Doctor of Philosophy (PhD) Heersink School of Medicine

Articles 31 - 52 of 52

Full-Text Articles in Medicine and Health Sciences

Ventral Hippocampal Input To The Medial Prefrontal Cortex Regulates Social Memory, Mary Leann Phillips Jan 2019

Ventral Hippocampal Input To The Medial Prefrontal Cortex Regulates Social Memory, Mary Leann Phillips

All ETDs from UAB

Both the ventral hippocampus (vHIP) and medial prefrontal cortex (mPFC) are active participants in the neural circuitry activated by social interaction, and are both necessary for certain aspects of social behavior. Additionally, synaptic projections from the ventral hippocampus (vHIP) to the medial prefrontal cortex (mPFC) are implicated in several neuropsychiatric disorders. Using the Mecp2 knockout (KO) mouse model of Rett syndrome, an autism-associated disorder with network level deficits in the vHIP and mPFC as well as aberrant social behavior, we strove to determine the role of vHIP-mPFC in social behavior. Here, we show that the vHIP-mPFC projection is hyperactive in …


The Reductive Stress Reducto-Mir: Emerging Insight Into Microrna-671, Justin Michael Quiles Jan 2019

The Reductive Stress Reducto-Mir: Emerging Insight Into Microrna-671, Justin Michael Quiles

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Excessive accumulation of reactive oxygen and nitrogen species (ROS/RNS) promotes cardiac pathophysiology. Although extreme oxidative burden is cytotoxic, ROS/RNS are continually generated within multiple domains of cardiac myocytes, and these species play fundamental roles in signal transduction through reversible thiol oxidation. Nuclear factor, erythroid 2 Like 2 (Nfe2l2/NRF2) is activated by ROS/RNS and binds cis regulatory antioxidant response elements (AREs) to induce the expression of a host of thiol oxidoreductases which regulate signaling events at the post-translational, transcriptional and epigenetic levels. Although oxidative stress has been linked to cardiac disease, adaptive processes in the heart require reduction-oxidation (redox) reactions as …


Pannexin 1 Channel Inhibition To Prevent Triggered Arrhythmia, Grace Elizabeth Salzer Jan 2019

Pannexin 1 Channel Inhibition To Prevent Triggered Arrhythmia, Grace Elizabeth Salzer

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The mechanism of triggered arrhythmia generation involves inappropriate diastolic calcium (Ca2+) releases from the sarcoplasmic reticulum that promote membrane depolarization when the released Ca2+ is transported out of the cardiomyocyte via the sodium Ca2+ exchanger (NCX). If membrane depolarization is large enough, these events can trigger an ectopic action potential. However, it is not fully understood what physiological factors facilitate triggered events at the tissue level. Pannexin 1 (Px1), a large transmembrane conductance channel, can be activated by various stimuli including increases in intracellular Ca2+. We predict that during diastolic Ca2+ releases, Px1 becomes activated and together with the NCX, …


The Influence Of O-Glcnacylation On Dna 5-Hydroxymethylation In The Epileptic Hippocampus, Richard Gilbert Sanchez Jan 2019

The Influence Of O-Glcnacylation On Dna 5-Hydroxymethylation In The Epileptic Hippocampus, Richard Gilbert Sanchez

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Epilepsy is a neurological disorder that affects roughly 3 million Americans and 65 million individuals worldwide. Although there are several known causes of epilepsy, little is understood about the development of epilepsy or epileptogenesis. What has been observed through multiple studies of epilepsy is an alteration of the proteomic profile, along with a distinct change in post-translational modifications (PTM). Studies have focused on phosphorylation and a variety of kinases that are upregulated during epilepsy with little clinical translation. This dissertation investigates O-GlcNAcylation, a PTM that is highly intertwined with the cellular metabolism, and its epigenetic effects on gene expression via …


Regulation Of St6gal-I In Cancer: Sox2 Identified As Novel Driver Of St6gal-I Expression, Kaitlyn Alexandra Dorsett Jan 2019

Regulation Of St6gal-I In Cancer: Sox2 Identified As Novel Driver Of St6gal-I Expression, Kaitlyn Alexandra Dorsett

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ST6Gal-I is a sialyltransferase that functions to add an 2-6 linked sialic acid to N-linked glycoproteins. The expression of ST6Gal-I is upregulated in many cancers at both the mRNA and protein levels. ST6Gal-I has also been shown to promote cancer stem cell (CSC) characteristics including chemoresistance, tumor-initiating potential, and spheroid growth. However, the transcriptional drivers of ST6Gal-I expression in stem-like cells remain largely unknown. Herein we highlight that SOX2 and ST6GAL1 are both located on one of the most commonly amplified chromosomal segments in cancer, amplicon 3q26. Copy number gains in both SOX2 and ST6GAL1 are observed in roughly 25% …


Regulation Of Intestinal Innate Lymphoid Cells In Acute And Chronic Inflammation, Sarah Dulson Jan 2019

Regulation Of Intestinal Innate Lymphoid Cells In Acute And Chronic Inflammation, Sarah Dulson

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The Innate Lymphoid Cell (ILC) population encompasses five subpopulations that are increasingly appreciated to participate in immune responses to inflammation and injury as well as directly influence homeostasis in tissues throughout the body. ILCs are enriched at mucosal surfaces, such as the gastrointestinal tract, where they are transcriptionally poised for rapid activation. Therefore, ILCs contribute significantly to protective responses to infection, and can exacerbate inflammation and disease when dysregulated. Herein, we demonstrate two pathways that regulate intestinal ILC phenotype and function and delineate the impact of these pathways on both protective and pathogenic roles of ILCs. Using a murine model …


Dna Template Sequence Effects On Rna Polymerase I Transcription Elongation, Andrew Martin Clarke Jan 2019

Dna Template Sequence Effects On Rna Polymerase I Transcription Elongation, Andrew Martin Clarke

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The production of ribosomes represents the major synthetic effort of a rapidly dividing cell, and is intimately linked to the regulation of cell growth and proliferation. Developing a greater understanding of the mechanisms that regulate ribosome biogenesis is therefore crucial to understanding cellular control of the growth cycle. Ribosome biogenesis begins with the synthesis of the 35S ribosomal RNA (rRNA) by RNA polymerase I (Pol I). This RNA is co- and post-transcriptionally processed to produce the 18S, 5.8S, and 25S rRNAs. These RNAs are critical components of ribosomes, and Pol I has been demonstrated to be a key regulation target …


The Role Of Suppressor Of Cytokine Signaling 3 In Neuroinflammatory Disease, Zhaoqi Yan Jan 2019

The Role Of Suppressor Of Cytokine Signaling 3 In Neuroinflammatory Disease, Zhaoqi Yan

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The Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) pathway plays a critical role in cytokine-mediated responses in both innate and adaptive immunity, and dysregulation of the JAK/STAT pathway is linked to many inflammatory disorders. Multiple Sclerosis (MS) is an inflammatory demyelinating disease that affects the central nervous system, and both innate and adaptive immunity are involved in disease progression. STAT3 signaling is critically involved in MS pathology and is negatively regulated by Suppressor Of Cytokine Signaling 3 (SOCS3). Both increased STAT3 activation and reduced SOCS3 expression are observed in immune cells from patients with MS. Although the role of …


The Anti-Tumor Effects Of Hur Inhibition In Glioblastoma, Jiping Wang Jan 2019

The Anti-Tumor Effects Of Hur Inhibition In Glioblastoma, Jiping Wang

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Glioblastomas (GBMs) are the most malignant primary brain tumor. GBMs represent 14.7% of total primary CNS tumors and 47.7% of malignant CNS tumors. The median survival of GBM is 18-20 months, while five-year survival rate is only 5.6%. GBMs are maintained by glioma stem cells (GSCs), and poor treatment outcomes are linked to the high resistance of GSCs to radiation and chemotherapy, and the immunosuppressive tumor microenvironment. The mRNA binding protein HuR is a key regulator of tumor growth and development based upon the fact that HuR targets mRNAs that are broadly involved in tumorigenesis. We have previously shown that …


Using Peptide Mimetics To Probe Protein-Protein Interactions Significant In Cancers, Robert H. Whitaker Jan 2019

Using Peptide Mimetics To Probe Protein-Protein Interactions Significant In Cancers, Robert H. Whitaker

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Protein-protein interactions are critical for cell life. One aspect of cellular regulation where such protein-protein interactions occur is in the highly regulated process of programmed cell death (or apoptosis). Apoptosis is critical for normal tissue homeostasis, differentiation, and if dysregulated is a driver of disease including cancers. At the center of apoptotic regulation is the BCL2 protein family whose intra-familial protein-protein interactions balance cell stress signaling either allowing the cell to survive or inducing mitochondrial cell death. These BCL2 protein interactions are accomplished through the BH3 motif. While unique to the BCL2 family, a similar motif, the reverse BH3, has …


The Role Of Protein O-Glcnacylation In Regulating Mitochondrial Function, Jalessa Nicole Wright Jan 2019

The Role Of Protein O-Glcnacylation In Regulating Mitochondrial Function, Jalessa Nicole Wright

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The attachment of O-linked-N-acetylglucosamine (O-GlcNAc) to the serine/threonine residues of proteins has emerged as an important regulatory mechanism in transcriptional regulation, protein activation as well as cell survival. Several studies have reported that elevated O-GlcNAc levels have adverse effects on mitochondrial function. These negative effects have been linked to O-GlcNAc modification of mitochondrial proteins that are integral across multiple metabolic cell processes i.e. VDAC, NDUFA9 and DRP-1. Mitochondrial complexes I, III and IV all contain subunit proteins that are O-GlcNAc modified and increased O-GlcNAcylation of these proteins is associated with deficits in oxidative phosphorylation in these models. Conversely, it has …


Modulation Of Klotho Affects Dendritic Spine Remodeling And Neuronal Network Activity, Hai T. Vo Jan 2019

Modulation Of Klotho Affects Dendritic Spine Remodeling And Neuronal Network Activity, Hai T. Vo

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Klotho protein expression has profound effects on lifespan where klotho-deficient mice exhibit premature aging phenotypes and live only to ~8 weeks of age while klotho-overexpressing mice have lifespans that are at least 20% longer than wild-type mice. Klotho expression also has similar effects on cognitive function as klotho-deficient mice develop cognitive impairment by 7 weeks of age and klotho-overexpressing mice show enhanced cognitive function. These effects also extend to humans as polymorphisms that alter circulating levels of klotho have likewise effects on lifespan and brain function. Despite the fact that modulation of klotho expression has reciprocal effects on cognitive function, …


O-Glcnac Regulation Of Inhibitory Circuits, Kavitha Abiraman Jan 2019

O-Glcnac Regulation Of Inhibitory Circuits, Kavitha Abiraman

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Post translational modification of proteins plays a crucial role in regulating their function, and the role of one such modification, termed O-GlcNAcylation, is understudied. O-GlcNAcylation involves the dynamic cycle of adding and removing an O-linked N-acetylglucosamine (O-GlcNAc) by the enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which are highly expressed in the hippocampus. Enzymes that catalyze O-GlcNAcylation are found at both presynaptic and postsynaptic sites, and O-GlcNAcylated proteins localize to synaptosomes. We have shown that acute and selective increase in O-GlcNAcylation of AMPAR GluA2 subunits underlies expression of a novel form of LTD at CA3-CA1 synapses (O-GlcNAc LTD), as well …


Novel Approaches To Enhance Translational Readthrough Efficacy For Cystic Fibrosis Nonsense Mutations, Jyoti Sharma Jan 2019

Novel Approaches To Enhance Translational Readthrough Efficacy For Cystic Fibrosis Nonsense Mutations, Jyoti Sharma

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Cystic fibrosis (CF) is a monogenic autosomal recessive disease caused by over 1,900 naturally occurring variants in the CF transmembrane conductance regulator (CFTR). CFTR is an epithelial anion channel which regulates the movement of chloride and bicarbonate ions. Mutations in the CFTR causes diminished CFTR protein and/or reduced CFTR function that lead to clinical manifestations. These include severe epithelial dysfunction of multiple tissues, including the lungs, intestine, pancreas, and reproductive organs. Premature termination codons (PTC), or nonsense mutations, are among the most severe CFTR variants and occur in ~11% of the CF population. PTCs are caused by the presence of …


Targeting The Nad Salvage Pathway For The Treatment Of The Parasitic Disease Schistosomiasis, Michael David Schultz Jan 2019

Targeting The Nad Salvage Pathway For The Treatment Of The Parasitic Disease Schistosomiasis, Michael David Schultz

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Schistosomiasis, also known as bilharzia, is the third most common parasitic infection worldwide and a major source of morbidity and mortality in developing countries. Caused by trematodes in the genus Schistosoma, this parasitic disease has no vaccine therapy and resources for drug development are scarce. Despite an unknown mechanism of action, praziquantal has become the primary source of treatment due to its efficacy against all species of Schistosoma. However, with increased drug resistance in endemic areas and low activity against immature parasites, relying on this single drug is unsustainable and risky. Hence, there is a growing need for new, safe …


Novel Biomarkers For Parkinson Disease, Shijie Wang Jan 2019

Novel Biomarkers For Parkinson Disease, Shijie Wang

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Parkinson disease (PD) is the second most common neurodegenerative disorder with no reliable biochemical biomarkers for disease prediction or progression, nor disease-modifying treatments to slow the relentless progression. Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are known to increase LRRK2 kinase activity and increase the risk for late-onset PD. In this thesis, I discovered that LRRK2 is secreted into exosomes in urine and CSF, where LRRK2 kinase activity, reflected by autophosphorylation at pS1292 site, is preserved and reflective of cytosolic LRRK2 levels. In a cohort of biosamples from LRRK2 mutation carriers and matched controls, with and without PD, …


Integration Of Yeast Phenomics And Cancer Pharmacogenomics To Model Precision Medicine, Sean Santos Jan 2019

Integration Of Yeast Phenomics And Cancer Pharmacogenomics To Model Precision Medicine, Sean Santos

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Precision medicine aims to optimize disease treatment by considering the differential influence of functional genetic variation on phenotypic outcomes and therapeutic efficacy. However, current precision medicine paradigms lack consideration of the abundance of genetic interaction and ensuing complexity of phenotypes, thus thwarting resolution of gene-drug interaction at a systems level and ‘precise’ predictions for most patients. Yeast phenomics enables quantitative, high-resolution experimental modeling of gene-drug interaction phenotypes at a systems level by measuring growth curves for the ~6000 yeast knockout/knockdown library strains, which can guide a more global resolution of disease and treatment complexity at the organism level. We postulate …


Transcriptional Dynamics Of Dopaminergic Signaling, Katherine Elizabeth Savell Jan 2019

Transcriptional Dynamics Of Dopaminergic Signaling, Katherine Elizabeth Savell

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Drugs of abuse increase dopamine concentrations in the nucleus accumbens, a key reward structure that integrates contextual and cue-related information and regulates motivated behavior. This surge of dopamine triggers cell signaling cascades that converge in the nucleus to cause changes in gene expression, which are thought to lead to the observed functional and structural alterations in the reward circuit after exposure to drugs of abuse. However, while various drugs of abuse cause transcriptional changes, previously available tools have not had the capacity to deeply characterize these gene programs. Therefore, we optimized a dual lentivirus CRISPR system for targeted gene modulation …


Context Fear Memory Formation Is Regulated By Hippocampal Lncrna-Mediated Histone Methylation Changes, Anderson Alan Butler Jan 2019

Context Fear Memory Formation Is Regulated By Hippocampal Lncrna-Mediated Histone Methylation Changes, Anderson Alan Butler

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The post-translational modification of histones regulates gene expression and is critical for the formation and maintenance of hippocampus-dependent long-term memories. Changes in gene-specific expression of various epigenetic marks during the aging pro-cess are sufficiently consistent as to be used as an aging landmark or epigenetic clock in both humans and other species; however, the molecular mechanisms which govern the application of these marks aging are poorly explored. Recently, long noncoding RNAs (lncRNAs) have been implicated as regulators of histone methyltransferases and other chromatin-modifying enzymes (CMEs). Despite the relevance of such mechanisms to both aging and memory formation, the behavioral relevance …


Genome Sequencing To Identify Novel Developmental Disorder Variation, Matthew Neu Jan 2019

Genome Sequencing To Identify Novel Developmental Disorder Variation, Matthew Neu

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The ability to quickly and accurately catalog an individual's genetic variation through genome sequencing has ignited a new era of diagnostic and therapeutic development for heritable disease. Although genome sequencing can provide a molecular diagnosis in a significant number of patients with suspected genetic disease, there remain a number of unsolved cases for which no pathogenic cause can be determined. This uncertainty can create a "diagnostic odyssey" in which sequential tests fail to provide a diagnostic resolution and can often delay beneficial treatment, impact family planning, and be emotionally challenging for patients and their families. Clearly, there is an unmet …


Dysregulation In The Central Nervous System Upon Mcmv Infection In Newborn Mice, Cathy Yea Won Sung Jan 2019

Dysregulation In The Central Nervous System Upon Mcmv Infection In Newborn Mice, Cathy Yea Won Sung

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Human cytomegalovirus (HCMV) infection is a major cause of morbidity in infants and children throughout the world. Between 0.2-1.2% of all live births is infected with HCMV in the United States. Approximately 5-15% of these newborn babies will develop long-term neurological damage resulting in motor disorders, mental retardation, and sensorineural hearing loss. Although the neurological sequelae associated with congenital HCMV infections are well characterized, little is known about the pathogenesis of the damage to the central nervous system (CNS). To study the pathogenesis of congenital HCMV infection, we have developed a mouse model in which newborn mice are infected intraperitoneally …


Therapeutic Mechanisms In Sickle Cell Nephropathy, Crystal Taylor Jan 2019

Therapeutic Mechanisms In Sickle Cell Nephropathy, Crystal Taylor

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Sickle cell disease (SCD) is a commonly inherited genetic blood disorder that causes hypoxia-induced polymerization of mutant hemoglobin resulting in erythrocyte sickling, transient microvascular occlusion, ischemic injury, and end-organ damage. Systemic endothelial dysfunction and vaso-occlusive episodes observed in SCD are particularly deleterious to the kidney, where the hypoxic, hyperosmotic environment of the medulla makes it particularly susceptible to ischemic injury. Over recent decades, chronic kidney disease has emerged as a significant contributor to mortality and morbidity in SCD patients. Despite a growing interest in the importance of sickle cell nephropathy (SCN), therapeutic options are limited and much remains undiscovered regarding …