Digital Commons Network^™

Determining The Role Of Neuregulin-1 And Its Erbb Receptors In The Pathogenesis Of Malignant Peripheral Nerve Sheath Tumors, Stephanie Brosius

All ETDs from UAB

Malignant peripheral nerve sheath tumors (MPNSTs) are the most common cause of death in patients with neurofibromatosis type-1. These aggressive, Schwann cell-derived tumors have no treatment beyond surgical resection. Developing targeted chemotherapeutics remains crucial to improving patient survival. The Schwann cell mitogen neuregulin-1 (NRG1) was shown to mediate the migration, proliferation and survival of MPNSTs. Furthermore, overexpression of NRG1 in Schwann cells (P0-GGF beta 3 mice) on an outbred C57BL/6J x SJL/J background induced the formation of neurofibromas and MPNSTs similar to human disease, yet these mice have intact neurofibromin. To determine if NRG1 acts within the same signaling cascade …

Cd5-Dependent Ck2 Activation Is Critical For The Maintenance Of B-1a B Cells, Kevin S. Cashman

All ETDs from UAB

CD5 has classically been shown to act as a negative regulator of antigen receptor signaling, however recent evidence has discerned that the CD5 molecule contains a previously undefined cytoplasmic domain which constitutively binds inactive CK2 and facilitates its activation through CD5 ligation. With the development of a mouse model which contains a micro-deletion knock-in form of CD5 which lacks the amino acids necessary to facilitate this CD5-CK2 interaction, it is now understood that CD5 plays a more significant role in cellular physiology than previously appreciated. T cells from this mouse model show increased AICD and dysregulation in T helper subset …

The Modulation Of High Density Lipoprotein Metabolism In Systemic Lupus Erythematosus, Leland Latham Black

All ETDs from UAB

Apolipoprotein A-I (ApoA-I), the major lipid-binding protein of high-density lipoprotein (HDL), can suppress inflammation and autoimmunity in hypercholesterolemic mice by modulating cellular cholesterol homeostasis and lipid oxidation. However, the cellular and molecular mechanisms involved are poorly understood, and whether ApoA-I or ApoA-I mimetic peptides can similarly exert immunosuppressive effects or improve inflammatory organ disease in SLE under normolipidemic conditions remains unresolved. We therefore first took a genetic approach in which bone marrow from SLE-prone Sle123 mice was transferred into wild-type, ApoA-I knockout (ApoA-I-/-) and ApoA-I transgenic (ApoA-Itg) mice. Transgenic expression of ApoA-I suppressed CD4+ T and B lymphocyte activation, reduced …

The Role Of The Developing Microbiome In Mucosal Defense Of The Neonatal Gut, Emily G. Blosser

All ETDs from UAB

Neonatal late-onset sepsis is invasive infection occurring after the first 48 hours of life, and one of the leading causes of death among preterm infants in the United States and abroad. Infections with Gram-negative bacteria, such as Klebsiella pneumonia, occurring when bacteria translocate across premature gut epithelium into the bloodstream, can be particularly severe. Preterm infants in the neonatal intensive care unit undergo intense antibiotic regimens due to high risk of infection. Paradoxically, prolonged exposure of preterm infants to empiric antibiotic therapy early in the hospital stay is associated with increased risk of intestinal infection and death after adjustment for …

Development Of A Patient-Derived Xenograft Model Of Ovarian Cancer To Characterize The Chemotherapy Resistant Population, Zachary Christopher Dobbin

All ETDs from UAB

Ovarian cancer while the second most common gynecologic malignancy is the most commons cause of death due to a gynecologic malignancy and the fifth most common cause of death to cancer in women. In 2014, there will be an expected 21,980 cases and 14,270 deaths. Unfortunately, the five-year survival for ovarian cancer is only 40% and this has barely increased over the past 30 years. New approaches need to be developed in order to study ovarian cancer and identify methods of overcoming chemotherapy resistance. This dissertation presents the work conducted in the development of a patient-derived xenograft model of ovarian …

The Role Of The Planar Cell Polarity Pathway In The Second Heart Field During Outflow Tract Morphogenesis, Tanvi Sinha

All ETDs from UAB

Outflow Tract (OFT) malformations underlie a majority of congenital heart defects (CHD) in humans and are a leading cause of childhood mortality. The OFT, which gives rise to the aorta and pulmonary artery of the heart, relies on the contribution of the Second Heart Field (SHF) progenitors in the pharyngeal and the splanchnic mesoderm, outside of the initial heart. OFT morphogenesis requires highly regulated SHF development involving the proliferation, differentiation and deployment of the SHF progenitors to the heart. Extensive studies elegantly demonstrate how transcriptional networks integrating signaling input from multiple pathways finely balance the proliferation and differentiation of SHF …

Characterization Of Phosphatidylinositol 4,5-Bisphosphate Regulation Of The Electrogenic Na/Bicarbonate Cotransporter Nbce1, Ian Michael Thornell

All ETDs from UAB

The electrogenic Na/bicarbonate cotransporter (NBCe1) is an acid/base regulator that is also involved in coordinating epithelial ion transport. Splice variants of NBCe1 differ at their cytosolic amino- (N-) and/or carboxy- (C-) termini. These different cytosolic termini impart differential regulation for each variant. For example, the N-terminus of NBCe1-A is autostimulatory, whereas the N-terminus of NBCe1-B and -C is autoinhibitory. We examine the regulatory role of PIP2 for NBCe1 splice variants. In the first study of this dissertation, we characterize the effect of increasing PIP2 on the activity of NBCe1-A, -B, and -C expressed in Xenopus laevis oocytes. Injecting PIP2 stimulated …

Peripheral Neuropathy In The Teetering Mice Results From Mutation Of The Escrt Component Hrs, Jennifer Ashley Watson

All ETDs from UAB

The sorting and degradation of endocytosed cargo by the endosome regulates many cellular functions common to all cells. Neural cells appear to be particularly vulnerable to perturbation in endo-lysosomal transport, and several neurological disorders are caused by a primary deficit in this pathway. In this dissertation, I show that the spontaneously occurring neurological mutation teetering (tn) is a single nucleotide substitution in the endosomal cargo-sorting component hepatocyte growth factor-regulated tyrosine kinase substrate (Hgs/Hrs) that reduces the abundance of HRS. By 3 weeks of age, the tn mice exhibit heightened pain sensitivity, muscle weakness and reduced muscle size. The loss of …

Mechanisms Of At101 [(-)-Gossypol] Induced Cytotoxicity In Malignant Peripheral Nerve Sheath Tumors, Niroop Kaza

All ETDs from UAB

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive Schwann cell-derived sarcomas and are the leading cause of mortality in patients with neurofibromatosis type 1 (NF1). Current treatment modalities have been largely ineffective resulting in a high rate of MPNST recurrence and poor five year patient survival. This necessitates the exploration of alternative chemotherapeutic options for MPNST patients. By evading apoptosis and utilizing protective mechanisms such as autophagy, cancer cells develop resistance to chemo- and radio-therapy. The overall goal of my thesis studies is to evaluate chemotherapeutic agents that can modulate both apoptosis and autophagy, thus target both cell death pathways …

Evaluation Of Tau As A Target For Alzheimer Disease And Other Conditions With Epileptiform Activity, Zhiyong Li

All ETDs from UAB

Alzheimer disease (AD) is a devastating neurological condition that slowly destroys memory and thinking skills of the affected patients. No disease-modifying medications are available. While all the treatment against Aߒ (major component of one hallmark pathology of AD) failed in clinical trials, tau (major component of the other hallmark pathology of AD) is emerging as a better alternative. Germline knockout of tau does not cause overt abnormalities in young mice and prevents AD-like deficits in mouse models of AD. Germline knockout of tau also confers resistance to epileptiform activity in models of both AD and epilepsy. Therefore tau is proposed …

Ksrp Ablation Enhances Lipolysis In White Adipose Tissue Through Reduced Mir-145 Expression, Yi-Yu Lin

All ETDs from UAB

White adipose tissue (WAT) releases fatty acids from stored triacylglycerol (TAG) for energy source. Here, we report that null mice for KH-type splicing regulatory protein (KSRP), an RNA-binding protein, resisted high fat diet (HFD) induced obesity. Target of deletion of KSRP regulates gene expression at multiple levels and enhances lipolysis in epididymal WAT (eWAT) due to up-regulation of genes promoting lipolytic activity. Expression of miR-145 is decreased due to impaired pri-miR-145 processing in Ksrp-/- eWAT. We show that miR-145 directly targets and represses Foxo1 and Cgi58, activators of lipolytic activity, and forced expression of miR-145 attenuates lipolysis. This study reveals …

Transmitted/Founder Siv In The Rhesus Macaque Model Of Hiv-1 Infection, Mike Lopker

All ETDs from UAB

Vitally important to HIV-1 vaccine and prevention studies is a well-characterized animal model that recapitulates the salient features of HIV infection in humans. SIVmac and SIVsmm infection of rhesus macaques share key virological and pathological parallels with HIV-1 infection of humans including target cell entry via CD4 and CCR5 (Edinger et al., 1997), progressive T cell loss (Swanstrom & Coffin, 2012), generalized immune activation and preferential loss of mucosal Th17 cells (Brenchley et al., 2008; Klatt & Brenchley, 2010), and a vigorous but ultimately ineffective adaptive immune response. Though commonly used as a vaccine challenge strain in the macaque model, …

The Role Of The Autophagy-Lysosome Pathway In In Vitro Models Of Neurodegeneration, Burton Mader

All ETDs from UAB

Recent studies have provided strong evidence that alterations in protein degradation pathways, such as the autophagy-lysosome pathway (ALP), may contribute to neuronal dysfunction and death which lead to clinical symptoms diagnosed with various neurodegenerative diseases. Parkinson's disease (PD) is characterized by neuromuscular abnormalities resulting from the pathological loss of substantia nigra dopaminergic neurons and widespread detection of Lewy bodies, intracellular protein inclusions composed primarily of α-synuclein. Additionally, altered gene function regulating the expression of α-synuclein has been directly linked to the PD pathogenesis. Autophagy is an intracellular degradation process that when altered can lead to the accumulation neurotoxic proteins such …

Altered Dna Methylation Contributes To Temporal Lobe Epilepsy And Associated Memory Deficits, Robert Ryley Parrish

All ETDs from UAB

Status epilepticus (SE) triggers molecular mechanisms that underlie the cellular and network changes that occur during the development of temporal lobe epilepsy (TLE). Additionally, gene expression alterations occur during epileptogenesis and in the epileptic brain that contribute to the persistence of the phenotype. However, the underlying epigenetic mechanisms responsible for aberrant gene expression that occur with epilepsy require further investigation. This dissertation investigates how DNA methylation in the hippocampus affects epilepsy and contributes to the memory impairments associated with the disorder. We found that DNA methylation was altered in a hippocampal subregion specific manner in the epileptic brain, displaying altered …

Molecular And Functional Interaction Of Runx2 And Sp7 For Development Of The Osteoblast Phenotype, Harunur Rashid

All ETDs from UAB

Runx2 and Sp7 transcription factors are essential for skeletogenesis. Deletion of either gene in mice results in failure of bone tissue development. However, underlying mechanisms responsible for a surprisingly similar phenotype by two distinctly unrelated proteins remain unknown. Sp7 is a Runx2 downstream target gene and is not expressed in Runx2 null mice. Thus, the Runx2 null model represents a compound phenotype of loss of both proteins. In contrast, normal levels of Runx2 mRNA are noted in Sp7 null mice. The failure of Runx2 to promote bone formation in Sp7 null mice suggests that Sp7 is required for Runx2 function …

Epithelial Sodium Channel Purification And X-Ray Crystallographic Studies, Bharat G. Reddy

All ETDs from UAB

Epithelial sodium channels (ENaC) play a critical role in maintaining Na+ homeostasis in various tissues throughout our body. Understanding of ENaC structure is mediated from studies of the homologous acid sensing ion channel 1 (ASIC1). However, ENaC has sev-eral notable functional differences compared to ASIC1, thereby providing justification for determination of its three-dimensional structure. Unfortunately, this goal remains elu-sive due to several experimental challenges. Of the subunits that comprise a physiological hetero-trimeric ENaC (α, ß, and γ), the α-subunit alone is of significant interest. αENaC is unique in that it is capable of forming a homo-trimeric structure capable of conducting …

Identification Of A New Schwannomatosis-Predisposing Gene And Study Of Splicing Defects Caused By Deep Intronic Nf1 Mutations Causing Neurofibromatosis Type 1, Jing Xie

All ETDs from UAB

Schwannomatosis is the third major form of the neurofibromatoses. Constitutional mutations in the SMARCB1 gene have been found only in ~50% of familial and <10% of sporadic schwannomatosis patients, suggesting additional predisposing genes exist. In the present study, we sequenced 3.72 Mb of evolutionary conserved sequences along 22q in 8 schwannomatosis patients without a SMARCB1 mutation in blood or schwannomas, and had a molecular signature consisting of somatic partial loss of 22q and a different NF2 mutation in every schwannoma. We identified LZTR1 germline mutations in 7/8 patients. Targeted sequencing of LZTR1 in 12 further patients with the same molecular signature identified 9 additional germline mutations. Loss of heterozygosity with retention of the LZTR1 mutation was present in all 25 schwannomas studied. Mutations segregated with disease in all available affected first-degree relatives. Our findings identify LZTR1 as a gene predisposing to an autosomal dominant inherited disorder of multiple schwannomas in ~80% SMARCB1-negative 22q-related schwannomatosis patients. Neurofibromatosis type 1, another major form of neurofibromatoses, is caused by loss-of-function mutations in the NF1 gene. Approximately 2% of identified NF1 mutations are deep intronic splice mutations causing the inclusion of an intronic cryptic exon in the mature mRNA. In the present study, we identified 12 different deep intronic splice mutations in 15 unrelated probands, resulting in exonization of different fragments from intron 30(23.2) or 31(23a). This study describes the largest collection of deep intronic mutations in NF1 reported so far, and pinpoints specifically the intronic sequences flanking the alternatively spliced exon 31(23a) as a hotspot for NF1 intronic splice defects. Further investigation by fragment and cloning analysis uncovered that the deep intronic mutations residing either 5' or 3' of exon 31(23a) predominantly or preferentially affect the type II isoform including exon 31(23a), suggesting that alternative splicing of exon 31(23a) depends and is regulated by multiple flanking intronic sequences.

Targeting Reactive Oxygen Species Production To Prevent Left Ventricle Remodeling In Volume Overload, Danielle Marie Yancey

All ETDs from UAB

Mechanisms of left ventricular dysfunction in cardiac volume overload (VO) are not well understood and currently, no medical therapy exists to treat this condition. Cardiac VO is marked by eccentric remodeling and contractile dysfunction ultimately resulting in cardiac failure. Oxidative stress is implicated in the pathophysiology of heart failure and recent evidence suggests mitochondrially- produced reactive oxygen species play a role in VO. To study VO, we used a rat model of aortocaval fistula (ACF). ACF results in early diastolic stress on the left ventricle (LV) and recapitulates the progressive nature of heart failure with contractile function being initially maintained …

Calreticulin Regulates Tgf-Ss Stimulated Extracellular Matrix Production, Kurt Zimmerman

All ETDs from UAB

Calreticulin (CRT) is an ER chaperone and regulator of Ca2+ signaling which is increased following ER stress and in fibrotic and vascular fibroproliferative disorders. Previously, we demonstrated that ER CRT regulates type I collagen transcript, trafficking, secretion, and processing into the extracellular matrix (ECM). These studies investigated the role of CRT in regulating ECM production through control TGF-ß dependent signaling pathways. Our studies show that CRT -/- mouse embryonic fibroblasts (MEFs), rat lung fibroblasts, and human IPF lung fibroblasts with siRNA knockdown of CRT had impaired production of type I collagen and fibronectin when stimulated with TGF-ß. Similarly, knockdown of …

Alpha-Camkii-Induced Vegf Expression Is Critical For The Growth Of Human Osteosarcoma, Paul Glenn Daft

All ETDs from UAB

Osteosarcoma (OS) is among the most frequently occurring primary bone tumors, primarily affecting adolescents and young adults. Despite improvements in OS treatment, more specific molecular targets are needed. One target of interest is alpha-Ca2+/calmodulin-dependent protein kinase II (α-CaMKII), a ubiquitous mediator of Ca2+-linked signaling, which has been shown to regulate tumor cell proliferation. Here, we show that α-CaMKII is highly expressed in primary OS tissue, and α-CaMKII deletion in human OS cell lines significantly reduces tumor burden in vivo. This inhibition of α-CaMKII results in decreased vascular endothelial growth factor (VEGF) protein secretion. Highly aggressive OS cells express VEGF receptor …

Sialic Acid: A Signal For Pneumococcal Egress From The Nasal Mucosa Into The Central Nervous System, Brandon L. Hatcher

All ETDs from UAB

Streptococcus pneumoniae (pneumococcus) is one of the leading causes of bacterial meningitis world-wide. The classic paradigm in the establishment of bacterial meningitis is that in the absence of physical trauma, infection in the peripheral blood is needed to cause invasion of the central nervous system (CNS). Our previous studies have shown that pneumococci, a frequent colonizer of the nasopharynx, can cause bacterial meningitis through a nonhematogenous route by which bacteria appear to travel along the olfactory nerves, through the cribriform plate to the olfactory bulbs and into the rest of the CNS. However, with the frequency of nasopharyngeal colonization and …

The Role Of Gene Fragmentation And Loss In Poxvirus Evolution, Eneida Hatcher

All ETDs from UAB

temperatures were near pivotal. The second chapter addresses the effects of fluctuating

Proteomic Analysis Of Rosenthal Fibers And The Development Of Software For Proteomics, Michael Raymond Heaven

All ETDs from UAB

The first aim of my thesis was to identify the protein composition of the protein aggregates, called Rosenthal fibers, which are the defining feature of Alexander disease (AxD). AxD is a rare neurodegenerative disease caused by mutations in the astrocyte specific protein, glial fibrillary acidic protein (GFAP). GFAP is a type III intermediate filament protein that is overexpressed in AxD. A guiding hypothesis of this project was that sequestration of vital cell proteins in the aggregates contributed to disease. The results of my research do not support this hypothesis, but do provide an in depth characterization of the protein composition …

Effect Of Protons On The Biology Of Human Gliomas, Avinash Vinayak Honasoge

All ETDs from UAB

Gliomas are the most common and most deadly primary brain cancer. Patient outcome for the most malignant variety, the World Health Organization (WHO) Type IV glioblastoma multiforme (GBM), has stagnated over the last several decades - the best combination treatment of surgical resection, radiation, and chemotherapy results in median survival of just over a year. To escape treatment, GBM must multiply and migrate in a confined brain environment. Both of these aspects of tumor cell invasion rely on the cell's ability to volume regulate; cell division involves a stage called "pre-mitotic condensation" in which the cells shrink immediately prior to …

Role Of Immunoregulatory Cytokines Il-12 And Il-23 In Skin Cancer, Tahseen H. Nasti

All ETDs from UAB

The incidence of new cases of skin cancer, which includes non-melanoma epithelial tumors and melanoma, has increased dramatically over the last few decades. Approximately 75% of all skin cancer-related deaths is due to melanoma, which is one of the most aggressive and difficult cancers to treat. The initiating events and mechanisms that influence melanoma development are not fully known, due in part to a paucity of animal models amenable to identifying new oncogenic mutations, and investigating mechanisms of immunosurveillance. Transgenic mouse models often harbor an activating mutation in a known oncogene in all somatic cells, and its widespread expression from …

Nonnutritive Sweetener And Weight Management: A Potential Paradox In Modern Dieting, Katharine Mary Wright

UNF Graduate Theses and Dissertations

Obesity is a serious health concern in modern society. One way to reduce caloric intake is with nonnutritive sweeteners (NNS). However, recent research suggests they may be compounding the obesity problem. Nonnutritive sweeteners have been linked to increased body mass in a few studies and may be a barrier to effective weight management for some individuals.

Under the framework of the health belief model, the research question was: Does this pattern of NNS-BMI covariance exist in young adults at the University of North Florida and, if so, are there other dietary or activity differences that might partially explain this relationship? …

Monitoring Brown Fat Metabolic Activity Using Microwave Radiometry: Antenna Design And Frequency Selection, Dario B. Rodrigues, Paul R. Stauffer, Paolo F. Maccarini

Department of Radiation Oncology Faculty Papers

This paper describes the use of microwave radiometry for monitoring brown fat metabolism (mBAT). The radiometric frequency band and receive antenna were optimized for coupling to 2-6 ml BAT depots in the supraclavicular region. Radiometric signal variations induced by higher metabolic activity resulting from a cold stimulus were calculated with electromagnetic and thermal simulations in a segmented computational model of the human neck including BAT. A 2.5 cm dia. log spiral antenna was selected as optimum using a 500 MHz bandwidth and center frequency 2.75 GHz. Results suggest sufficient sensitivity to track subsurface temperature variations during long term mBAT monitoring …

Peripubertal Binge Ethanol, Age And Sex Modulate Microrna Expression In The Ventral And Dorsal Hippocampus Of The Adolescent Rat, Sarah Arianne Prins

Dissertations

Adolescent binge ethanol (EtOH) abuse induces long-term changes in gene expression, resulting in an increased risk for the development of adult mood disorders. microRNAs (microRNAs) are small, noncoding RNAs that regulate gene expression by translational repression. microRNA altered in response to EtOH and puberty in the developing brain. The biogenesis of mature 22-24 nucleotide (nt), single-stranded microRNAs involves Drosha and Dicer enzymatic processing of microRNA precursors. A mature microRNA imperfectly base pairs with messenger RNA (mRNA) target genes,which leads to mRNA cleavage or translational repression. Our lab has found that repeated binge EtOH exposure alters gene expression in the hypothalamus …

Effects Of Cpla-2 On The Migration And Proliferation Of Human Vascular Smooth Muscle Cells And The 2-D Migratory Patterns Of Tropomyosin In Femoral And Abdominal Aorta Tissue, Jaimeson Thomas Powell

Theses and Dissertations

Abstract 1: Platelet derived growth factor BB (PDGF BB) has an important influence on smooth muscle cell proliferation in restenosis and atherosclerosis. Our understanding of different signal transduction pathways involved in the response of smooth muscle cells to PDGF BB is potentially significant for understanding and manipulating these processes. Prior studies have demonstrated a crucial activation of cytosolic phospholipase A2 (cPLA2) in smooth muscle cells to PDGF BB with the production of arachidonic acid and prostaglandin E2. In these studies we investigated the role for another PLA2, calcium-independent PLA2 (iPLA2) in comparison to cPLA2 on smooth muscle cell migration and …

A Study Of Functional Recovery And Axonal Plasticity Following Tbi And Anti-Nogo-A Immunotherapy, Jennifer Crystal Biesiadecki

Master's Theses

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality globally and often results in long term disability. Unfortunately, the success of rehabilitation techniques as therapy for TBI is limited, which may be due to the growth restrictive environment of the adult central nervous system (CNS). This environment is thought to result from glial scars, lack of neurotrophic factors, and the presence of an array of growth-inhibitory molecules. One such growth-inhibitory molecule is the protein Nogo-A. Our laboratory has shown that neutralization of Nogo-A with anti-Nogo-A immunotherapy after ischemic stroke results in improvement in functional recovery in the …