Digital Commons Network^™

Structural And Biochemical Charactereization Of Lrrk2, Zhiyong Liu

All ETDs from UAB

Mutations in the leucine rich repeat kinase 2 (LRRK2) gene are the most common known genetic cause of Parkinson disease (PD) , with pathogenic mutations located within each of the two catalytic cores of the protein, the GTPase and kinase domains. The most prevalent pathogenic mutation, G2019S increases kinase activity up to 5-fold, causing significant changes in the protein’s biochemical behavior. Other mutations such as R1441G and I2020T have also been demonstrated to increase LRRK2 kinase activity, however, the detailed mechanisms remains unclear. A major limitation in the field is the lack of structural information of LRRK2. This dissertation detailed …

A New Form Of Rod Photoreceptor Light Adaptation, Alex S. Mckeown

All ETDs from UAB

In the first step in light perception, rod and cone photoreceptors convert photon absorption into an electrical impulse that is transmitted through the visual pathway. While the biochemistry and the signaling physiology have largely been defined in dark-adapted, isolated mammalian rods, there are still unanswered questions regarding photoreceptor light adaptation processes that involve extracellular components. In particular, the proteins of the interphotoreceptor matrix have not been considered in the studies of rod signaling and adaptation. This thesis details a new form of light adaptation, now known as adaptive potentiation (AP), in which extracellular components act on rods to transiently increase …

Dna Methylation Regulates Neuronal Synaptic Scaling And Intrinsic Membrane Excitability, Jarrod P. Meadows

All ETDs from UAB

Learning and memory rely on long-lasting, experience-dependent adaptations in synaptic and non-synaptic forms of neuronal plasticity. Previous evidence implicates transcriptional and epigenetic mechanisms, including DNA cytosine methylation, as critical regulators of site-specific, Hebbian alterations in synaptic efficacy such as long-term potentiation (LTP) and long-term depression (LTD). However, whether DNA methylation modulates cell-wide, non-Hebbian homeostatic adaptations like synaptic scaling and intrinsic plasticity (IP) is unclear. Whereas synaptic scaling involves bidirectional changes in postsynaptic receptor density in response to chronic alterations in neuronal activity, IP involves the activity-dependent attunement of passive and/or active membrane properties that govern action potential (AP) firing. This …

Nadph Oxidase-Derived Superoxide: A Potentiator Of Autoimmune Responses In Type 1 Diabetes, Lindsey E. Padgett

All ETDs from UAB

Type 1 Diabetes (T1D) is an autoimmune disease culminating in pancreatic β-cell destruction, inducing reactive oxygen species (ROS), pro-inflammatory cytokines, and islet-infiltrating leukocutes. Macrophages, one of the first islet-infiltrating cells in T1D, secrete ROS and pro-inflammatory cytokines, which lyse pancreatic β-cells and activate diabetogenic T cells to further propagate β-cell destruction, while autoreactive CD4 T cells recruit islet-infiltrating, pro-inflammatory, M1 macrophages, and enhance CD8 T cell cytotoxicity. We previously demonstrated the importance of NADPH oxidase (NOX)-derived ROS synthesis in T1D, as Non-obese diabetic (NOD) mice lacking NOX-derived superoxide (NOD.Ncf1m1J) exhibited a delay in spontaneous and adoptive transfer of T1D. In …

The Role Of C-Reactive Protein In Acute Kidney Injury, Melissa A. Pegues

All ETDs from UAB

Acute kidney injury (AKI), which manifests as an abrupt decline in renal function, occurs in ~1% of all hospitalization. Ischemia reperfusion injury (IRI), a common cause of AKI, can occur in any situation where blood flow to the kidney is significantly reduced such as hypertensive crisis, cardiovascular surgery, and inevitably during renal transplantation. Mortality from AKI is up to 80% due to incomplete knowledge of the pathogenesis of IRI and the lack of an effective therapy. It is thought that cellular damage as a result of hypoxia signals the release of proinflammatory cytokines that lead to a systemic inflammatory response. …

Energy Metabolism Of Platelets During Activation, Oxidative Stress And Storage, Saranya Ravi

All ETDs from UAB

The principal function of platelets is to regulate hemostasis, and dysfunction of platelet aggregation or activation can lead to either excessive thrombotic or hemorrhagic complications. It has been shown that the ability to generate ATP and exposure to oxidative stress can affect platelet thrombotic potential. While platelet metabolism has been extensively studied, the importance of substrate availability and metabolic plasticity in regulating aggregation under physiological or pathological conditions is not well understood. In this dissertation, we examined the reliance of platelets on different metabolic substrates, the importance of ATP production for aggregation in response to thrombin stimulation, metabolic stress following …

Glutamate And The Biology Of Malignant Glioma, Stephanie Marie Robert

All ETDs from UAB

Malignant gliomas are the most prevalent primary brain tumor. They are highly aggressive and lack effective treatment options. Standard therapy includes a combination of radiation, chemotherapy, and tumor resection; however, even with aggressive treatment, median patient survival remains a dismal 12 – 14 months after diagnosis. Research has focused on understanding the unique biological mechanisms involved in glioma growth and survival in an effort to design novel therapies to treat this devastating disease. In the unique environment of the brain, gliomas have developed the ability to grow and survive at the cost of the normal surrounding brain tissue. Glutamate, the …

Nonsense Suppression In A Cftr Mouse Model And Analysis Of Animo Acids Inserted At Cftr Premature Termination Codons In Mammalian Cells, Xiaojiao Xue

All ETDs from UAB

A nonsense mutation introduces a premature terminations codon (PTC) into an open reading frame (ORF) upstream of a normal stop codon and results in truncated protein production. In frame PTCs account for ~11% of all mutations that cause human genetic diseases. To treat PTC-associated disorders, one approach is to use drugs that facilitate the insertion of amino acids carried by near-cognate aminoacyl-tRNAs at PTCs. Aminoglycosides were shown to suppress nonsense mutations and restore full-length protein production. This process is also termed as readthrough. However, their low efficiency and their potential to induce ototoxicity and nephrotoxicity limits their long-term application for …

Socs3 Deficiency In Myeloid Cells Promotes Tumor Development, Hao Yu

All ETDs from UAB

STAT3 signaling is a major intrinsic pathway for cancer inflammation owing to its frequent activation in malignant cells, and key role in regulating many genes crucial for inflammation in the tumor microenvironment. Persistently activated STAT3 increases tumor cell proliferation, survival, and invasion while suppressing anti-tumor immunity. Suppressor Of Cytokine Signaling (SOCS) proteins are negative regulators of the JAK/STAT pathway, and generally function as tumor suppressors. The absence of SOCS3 in particular leads to heightened activation of the STAT3 transcription factor. In the present study, we demonstrate that genetic deletion of SOCS3 specifically in myeloid cells significantly enhances tumor growth, which …

Functional Role Of Mepe In Tooth Mineralization: Mediation By Tgf-Beta1, Angela Gullard

All ETDs from UAB

Transforming growth factor-β1 (TGF-β1) is one of the most abundant cytokines of the dentin-pulp complex that regulates a broad range of biological processes related to matrix synthesis and ultimately tooth formation, including secretion and mineralization of the dentin extracellular matrix (DECM). TGF-β1 mediates odontoblast cytodifferentiation from precursor dental pulp cells, being up-regulated in odontoblasts and then incorporated into the DECM as a reservoir that can be utilized in times of mechanical, chemical, or bacterial insult. Formation of the DECM is modulated by the actions of small integrin-binding ligand N-linked glycoproteins (SIBLINGs), which include DMP-1, DSPP, BSP, SPP1, and MEPE, with …

G Protein-Coupled Inwardly-Rectifying Potassium (Girk) Chanels Mediate Entrainment Of Circadian Rhythms, Lauren Marie Hablitz

All ETDs from UAB

Circadian rhythms are 24-hour cycles in biological and behavioral processes. These cycles enable an organism to predict changes in its environment, like changes in food availability and seasonality. Although endogenously driven, these rhythms can entrain or synchronize to daily changes in the environment, allowing the animal to adapt. One way entrainment occurs is shifts in circadian phase following the presentation of nonphotic, or non-light, stimuli, such as exercise, arousal, or stress at certain times of day. The molecular mechanisms underlying nonphotic entrainment are poorly understood - specifically, how nonphotic cues alter excitability within the suprachiasmatic nucleus (SCN) of the hypothalamus, …

Bcla As An Adjunct To Current Bacillus Anthracis Vaccination And Therapy Protocols, Juan Bosco Rodriguez Barrantes

All ETDs from UAB

Bacillus anthracis (Ba) is a Gram,-positive zoonotic bacterium that causes inhala- tional, cutaneous and intestinal Anthrax Disease. Although the infectious form of Ba is its endospore (spore), only the tripartite toxin-producing vegetative bacteria causes disease pathology. While current vaccination strategies target the Protective Antigen (PA) com- ponent of this toxin, vaccine-elicited immunity to the spore form of Ba is lacking. How- ever, vaccines targeting spore components of Ba have the potential to neutralize the in- fectious form of Ba. We sought to determine if antibodies elicited through immunization with the main antigenic component of the spore surface- Bacillus collagen-like protein …

Investigating The Role Of Myristoylated Alanine Rich C Kinase Substrate's (Marcks's) Effector Domain In Lung And Brain Cancer Biology, Timothy D. Rohrbach

All ETDs from UAB

In this study, we investigated the role MARCKS's Effector Domain plays in lung and brain cancer biology. Initially, we identified that MARCKS was present in a range of lung cancer histologies including: squamous cell, adenocarcinoma, and normal lung tissues among others. In addition, lung adenocarcinoma patients with a mutation in the MARCKS gene correlated with decreased survival as determined by The Cancer Genome Atlas. In vitro studies identified that the phosphorylation status of MARCKS's Effector Domain was able to influence lung cancer radiation sensitivity. When MARCKS's Effector Domain was in a non-phosphorylated state, A549 lung cancer cell lines experienced increased …

Role Of Vapb/Als8 Signaling Through Lar Receptor, Jessica Lindsey Winek Schultz

All ETDs from UAB

In humans, a P56S point mutation in the VAPB/ALS8 MSP domain is associated with amyotrophic lateral sclerosis (ALS) and late-onset spinal muscular atrophy (SMA). The N-terminal MSP domain is cleaved from the C-terminus, and secreted through an unknown, nonconventional manner. The P56S mutation inhibits secretion of the MSP domain. We use Caenorhabditis elegans to study live secretion of VPR-1, as well as to understand vMSP receptor signaling in muscle and gonad. To study the secretion mechanism of VPR-1 we created a transgenic line of C. elegans with a fluorescently tagged VPR-1. Using this model, we were able to visualize live …

Effects Of Nicotine Withdrawal On Motivation, Reward Sensitivity And Reward-Learning, Jason A. Oliver

USF Tampa Graduate Theses and Dissertations

Research on addictive behavior has traditionally emphasized the role that primary reinforcing effects of drugs of abuse plays in the development and maintenance of dependence. However, contemporary behavioral economic theory and animal models of nicotine dependence suggest the need for greater attention to the impact that response to alternative rewards may have on smoking behavior. The present study sought to investigate the impact of nicotine withdrawal on self-report, behavioral and neural indices of motivation, immediate response to rewards and the capacity to learn and modify behavior in response to positive and negative feedback. Heavy smokers (n = 48) completed two …

Development Of An Avian Model For Identifying Individual Differences In Drug Vulnerability, Beth A. Rice

Theses and Dissertations--Psychology

The attribution of incentive salience to cues that become associated with drugs of abuse is a critical characteristic of individuals who may be vulnerable to drug addiction. Rodents with the propensity to sign track are thought to be vulnerable to drug abuse. The goal of the current work was to investigate whether sign trackers (STs) would acquire cocaine conditioned place preference (CPP) to a discrete cue using an avian species. In Experiment 1, sign and goal trackers (GTs) were first identified using a one third rank order split. Following identification, cocaine-CPP was conducted with a discrete cue in each end …

Effects Of Brain-Derived Neurotrophic Factor And Its Signaling Pathway On Sensory Neuronal Activation During Colitis, Fiza Hashmi

Theses and Dissertations

Visceral hypersensitivity is the heightened response to sensory stimuli. Visceral sensations are transmitted through primary afferent neurons in the dorsal root ganglion (DRG) and the sensitization of the neural pathway leads to modification in spinal ascending and descending neurons. The aim of this investigation is to determine the effects of brain-derived neurotrophic factor (BDNF) and its signaling pathway on sensory neuronal activation during colitis. In order to evaluate this, levels of calcitonin-gene related peptide (CGRP), a neuropeptide marker for nociceptive transmission, and phosphorylated cAMP-response element binding protein (pCREB), a molecular switch in neuronal plasticity, were studied in response to BDNF …

Effects Of Hiv-1 Viral Protein Tat On The Viability And Function Of Oligodendroglial Cells, Shiping Zou

Theses and Dissertations

Myelin pallor is frequently reported in HIV patients, and can occur in the CNS prior to other evidence of disease process. Our exploratory studies showed that oligodendrocytes (OLs) are direct targets of HIV-1 Tat (transactivator of transcription). Tat induces a dose-dependent increase of intracellular Ca²⁺ level ([Ca²⁺]_i) in cultured murine OLs, which can be attenuated by ionotropic glutamate receptor (iGluR) antagonists MK801 and CNQX. The Tat-induced [Ca²⁺]_i increase leads to increased death in immature (O4⁺, MBP^-), but not mature (O4⁺, MBP⁺) OLs, over 96 …

Meta-Analysis Of Gene Expression Studies, Umaporn Siangphoe

Theses and Dissertations

Combining effect sizes from individual studies using random-effects models are commonly applied in high-dimensional gene expression data. However, unknown study heterogeneity can arise from inconsistency of sample qualities and experimental conditions. High heterogeneity of effect sizes can reduce statistical power of the models. We proposed two new methods for random effects estimation and measurements for model variation and strength of the study heterogeneity. We then developed a statistical technique to test for significance of random effects and identify heterogeneous genes. We also proposed another meta-analytic approach that incorporates informative weights in the random effects meta-analysis models. We compared the proposed …

Psychoactive Synthetic Cathinones (Or 'Bath Salts'): Investigation Of Mechanisms Of Action, Farhana Sakloth

Theses and Dissertations

Synthetic cathinones represent threatening and high abuse-potential designer drugs. These are analogs of cathinone (the b-keto analog of amphetamine (AMPH)) a naturally occurring stimulant found in the plant Catha Edulis. Methcathinone (MCAT) was the first synthetic analog of cathinone to be identified in 1987 by Glennon and co-workers and it exerted its action primarily through the dopamine transporter (DAT). Most central stimulants exert their action via monomaine transporters by causing either the release (e.g. cathinone analogs such as MCAT) or by preventing the reuptake (e.g. cocaine) of the neurotransmitter dopamine (DA) thus increasing the extracellular synaptosomal concentration of this …

Interaction Between Atm Kinase And P53 In Determining Glioma Radiosensitivity, Syed F. Ahmad

Theses and Dissertations

Glioblastoma multiforme (GBM) is the most common primary brain tumor. Studies have shown that targeting the DNA damage response can sensitize cancer cells to DNA damaging agents. Ataxia telangiectasia mutated (ATM) is involved in signaling DNA double strand breaks. Our group has previously shown that ATM inhibitors (ATMi) sensitize GBM cells and tumors to ionizing radiation. This effect is greater when the tumor suppressor p53 is mutated.

The goals of this work include validation of a new ATM inhibitor, AZ32, and elucidation of how ATMi and p53 status interact to promote cell death after radiation. We propose that ATMi and …

Measuring The Impact Of Recognized Patient-Centered Medical Homes (Pcmh), Rick Moore

Theses and Dissertations

This dissertation proposal seeks to understand if the increasingnumbers (density) of recognized PCMH practices incommunities affect avoidable hospitalizations related toambulatory care sensitive conditions (ACSC), as measured bythe AHRQ Composite Prevention Quality Indicators (PQI). Theresearch has two purposes: 1. Establish constructs and hypotheses to measurethe effect of the increasing numbers of NCQA-Recognized PCMH practices in communities(counties). 2. Using an outcomes-based measurement approach,investigate the relationship between growingdensities of NCQA-Recognized PCMH practicedoctors among all primary care doctors (PCD) ina community and the associated impact on theutilization of inpatient care, specifically related toACSCs, as measured by the AHRQ CompositePQIs.

The research is quasi-experimental in …

Conduction States Of The Human Dopamine Transporter, Krasnodara Cameron

Theses and Dissertations

Dysregulation of dopaminergic homeostasis has been established as the primary source of numerous neurological disorders including Parkinson’s and drug addiction. A tonic increase of dopamine (DA) in the nucleus accumbens is required for associating everyday events and behaviors with rewards. Yet many addictive exogenous compounds such as amphetamine (AMPH) and cocaine (COC) produce a much greater augmentation of synaptic DA levels that are linked to euphoria and a shift in behavior towards drug seeking. The protein responsible for maintaining extracellular levels of DA is the dopamine transporter (DAT). It is primarily located in the perisynaptic area at terminals of pre-synaptic …

Incorporation Of Molecular Diagnostics Into Medical Laboratory Science Curriculum: Clinical Facilities Expectations. An Asynchronous, Iterative, Online Delphi Study., Barbara Kraj

Theses and Dissertations

The medical laboratory science (MLS) profession is in need for published molecular diagnostics competency-based standards and curriculum. To assess their expectations of new MLS graduates, professionals performing and supervising performance of clinical molecular assays were surveyed to rate the importance of relevant cognitive and psychomotor learning objectives. A modified, asynchronous, iterative online Delphi process was utilized for assessment of consensus on the importance of the objectives. The survey was delivered through online REDCap application. Program directors of 221 MLS programs accredited by the National Accrediting Agency for Clinical Laboratory Science (NAACLS) were asked to forward the first Delphi survey to …

Effects Of Hiv-1 Tat On The Enteric Nervous, Joy Ngwainmbi

Theses and Dissertations

More than 1.2 million people are estimated to be currently living with the human immunodeficiency virus (HIV) in the United States of America. The gastrointestinal (GI) tract is both a major target and an important component of HIV pathogenesis. The GI processes that are dysregulated during HIV infection are controlled by the enteric nervous system (ENS). Indeed, both clinical and experimental studies have implicated the ENS in HIV and simian immunodeficiency virus (SIV) pathogenesis. In addition to direct viral effects, the HIV virus also indirectly affects the GI tract via cellular and/or viral toxins released by infected cells. Trans-activator of …

Dual Pi3k/Mtor Inhibition With Bez235 Augments The Therapeutic Efficacy Of Doxorubicin In Cancer Without Influencing Cardiac Function, David E. Durrant

Theses and Dissertations

Cancer continues to be a leading cause death in the United States despite improved treatments. Cancerous lesions form after acquiring oncogenic driver mutations or losing tumor suppressor function in normal cells. Traditional therapies have included use of genotoxic substances that take advantage of the increased growth rate and loss of tumor suppressor function to cause cell death. One such drug is the anthracycline antibiotic doxorubicin (DOX). DOX interchelates into DNA and disrupts transcriptional machinery while also poisoning topoisomerase II. This results in single and double stranded DNA breaks, which if severe enough leads to either necrotic or apoptotic cell death. …

Inhibition Of Mtor Signaling Protects Against Myocardial Reperfusion Injury, Acute Myocardial Infarction, Scott M. Filippone

Theses and Dissertations

Acute myocardial infarction (AMI) is the leading cause of death worldwide. Currently, the best method of treating cardiac ischemia is early reperfusion which, itself, induces myocardial damage. The mTOR complex is a key regulator of cardioprotection against cell stressors. We hypothesized that reperfusion therapy with Rapamycin, a potent mTOR inhibitor, would reduce infarct size in adult mouse hearts. Rapamycin was administered at the onset of reperfusion following 30 min in situ LAD ligation. After 24 hours of reperfusion, myocardial infarct size and apoptosis were significantly reduced in rapamycin-treated mice compared to control. Rapamycin inhibited pro-apoptotic protein Bax and phosphorylation of …

Hypolipidemic Effects Of Nimesulide And Celecoxib In Experimentally Induced Hypercholesterolemia In Rabbits, Sagheer Ahmed, Saima Gul, Muhammad Zia-Ul-Haq, Muhammad Riaz

Turkish Journal of Medical Sciences

Hypercholesterolemia plays an important role in the development of atherosclerotic disease, which is one of the leading causes of mortality in the world. Previous studies showed that cyclooxygenase (COX) inhibitors could be used in treating hypercholesterolemia. The present study was designed to test whether COX-2 inhibition can improve lipid profiles in hypercholesterolemia. Materials and methods: Rabbits were fed a high-cholesterol diet to produce hypercholesterolemia. The role of COX-2 was evaluated using celecoxib and nimesulide. Rabbits were divided into 4 groups: the first with normal healthy rabbits, second with high-cholesterol diet and pretreatment with saline, third with high-cholesterol diet and pretreatment …

Selenium Status In Blood, Urine, And Hair Samples Of Newly Diagnosed Pediatric Cancer Patients, Serap Karaman, Banu Mansuroğlu, Kadri̇ye Kizilbey, Serap Derman, Afi̇fe Bi̇nnaz Hazar

Turkish Journal of Medical Sciences

Background/aim: Selenium (Se) is a trace element that has multiple functions. Low Se amounts in serum and hair have been reported in pediatric and adult cancer patients. The aim of our study was to evaluate Se levels in the serum, urine, and hair of pediatric cancer patients with leukemia, lymphoma, and solid tumors when compared with healthy children. Materials and methods: The concentrations of Se in the serum, hair, and urine of 32 Turkish children as healthy controls and 88 Turkish children diagnosed with acute leukemia (58), lymphoma (16), and solid tumors (14) were measured using inductively coupled plasma mass …

R990g Polymorphism Of Calcium Sensing Receptor Gene Is Associated With High Parathyroid Hormone Levels In Subjects With Vitamin D Deficiency: A Cross-Sectional Study, Hafsa Majid, Aysha Habib Khan, Tariq Moatter

Department of Pathology and Laboratory Medicine

Single nucleotide polymorphisms (SNPs), R990G and A986S of the calcium sensing receptor (CaSR) gene, are shown to influence response of parathyroid hormone (PTH) in subjects with optimal vitamin D levels. This cross-sectional study was conducted in subjects with vitaminDdeficiency (VDD) to observe association’s betweenCaSR polymorphisms, plasma iPTH, and serumcalcium levels. Adult females (𝑛 = 140) with known VDD, intact parathyroid hormone (iPTH), and calcium levels were recruited for genotype analysis.The frequencies of the 986 alleles GG, GT, and TT were 68%, 25%, and 7%, respectively, whereas the frequencies of the 990 alleles AA, AG, and GG were 80%, 8.9%, and …