Digital Commons Network^™

Role Of The Human Cytomegalovirus Tegument Protein Pp150 In The Trafficking And Assembly Of Infectious Virions, Sabarish Vellatheri Indran

All ETDs from UAB

Human cytomegalovirus, a ubiquitous human pathogen, establishes a persistent infection in the infected host. HCMV assembly takes place in the nucleus and cytoplasm of infected cells by a complex and incompletely defined process. The viral DNA is enclosed by the capsid, which is surrounded by a proteinaceous tegument, which is covered by a cell-derived envelope studded with viral glycoproteins. The assembly pathway and protein interactions required for formation of the tegument layer and the function of most of the proteins in the tegument remain poorly understood. In this study, we investigated the functions of an essential abundant tegument protein, pp150, …

Molecular Mechanisms Of Hepatic Insulin Resistance Following Injury, Shaoning Jiang

All ETDs from UAB

Insulin resistance commonly occurs following injuries or critical illness independent of previous diabetic status. The development of insulin resistance and hyperglycemia is associated with increased mortality and morbidity in critically ill patients. However, the molecular mechanisms underlying the acute insulin resistance following injuries remain poorly understood. With an animal model of trauma and hemorrhage, we have previously demonstrated the rapid development of insulin resistance in liver, and a critical role of TNFα in hemorrhage-induced defects in insulin signaling following resuscitation. However, hepat-ic insulin signaling is impaired prior to a significant increase in plasma TNFα, suggesting the initial development of hemorrhage-induced …

In Vitro Elucidation Of The Role And Mechanism Of Rankl In Tnf-And Il-1-Mediated Osteoclast Formation And Function, Joel Jules

All ETDs from UAB

The receptor activator of NF-қB (RANK) ligand (RANKL) and its receptor RANK play a critical role in osteoclast biology. RANK has three tumor necrosis factor receptor associated factor (TRAF)-binding motifs [PFQEP369-373 (Motif 1), PVQEET559-564 (Motif 2), and PVQEQG604-609 (Motif 3)] that regulate osteoclast formation and function. RANK also contains a TRAF-independent motif (IVVY535-538) that commits bone marrow macrophages (BMMs), which are osteoclast precursors, to the osteoclast lineage for osteoclastogenesis. Notably, tumor necrosis factor-α (TNF) and interlukin-1 (IL-1) utilize TRAFs to initiate most of the signaling pathways known to be activated by RANKL but fail to form osteoclasts unless attended by …

The Role Of The Intracellular Signaling Pathway In Ehrlichia Canis Infection In Vitro, Chang-Hyun Kim

All ETDs from UAB

Ehrlichia canis is a pleomorphic obligatory intracellular gram-negative bacterium that causes tick-borne canine ehrlichiosis. A systematic investigation on the pathogenesis of the disease has been hindered largely by lack of a reliable quantitative assay. Using quantitative real time PCR (qPCR), a quantitative assay for E. canis was developed and validated. Using the qPCR, the intracellular proliferation kinetics of E. canis in the canine 030F cell-line was studied for the first time. Many intracellular bacterial pathogens have been shown to use Ca2+ signaling in the host cells to induce their own internalization and proliferation. However, it is not clear how Ca2+ …

Identification And Characterization Of Downstream Target Genes Of The Bmp Signaling Pathway, Nam Chul Kim

All ETDs from UAB

During nervous system development, neurons proliferate, differentiate, project their axons to their targets and make synapses with them. At the neuromuscular junction of Drosophila, these functional synapses enlarge as the body grows to maintain physiologically effective synaptic transmission with the muscles. Drosophila Bone Morphogenetic Protein (BMP) type II receptor, Wishful thinking (Wit), is important in this proper synaptic growth and function. To identify transcriptional targets of Wit signaling, we performed microarray experiments comparing normal controls to wit mutants. Through this study, we found that some of the verified target genes showed isoform-specific regulation in wit mutants, and that several neuropeptide …

Identification And Characterization Of Virulence Factors Of Mycoplasmas, Wenyi Luo

All ETDs from UAB

Mycoplasmas cause a group of diseases that are characterized by their chronicity and resistance to treatment. Diseases caused by the murine pathogens Mycoplasma pulmonis and Mycoplasma arthritidis are often studied as models of human diseases caused by a variety of chronic pathogens that induce a similar pathology. Among several candidate pathogenic factors, superantigens and degradative enzymes such as glycosidases are potentially important but not well characterized. The M. arthritidis mitogen (MAM) is a superantigen secreted by M. arthritidis. Its role with respect to arthritogenicity and toxicity is unclear. To improve the efficiency of transformation and hence enhance efforts to generate …

Lim Kinase 1 And Twinstar In Synaptic Plasticity Of Drosophila Motoneurons, James Brian Machamer

All ETDs from UAB

Modification of the actin cytoskeleton is essential for synaptic plasticity, which is believed to underlie the brain's capacity for learning and memory. Regulation of the actin cytoskeleton by LIM Kinases (LIMK1 and LIMK2) and their downstream targets Actin Depolymerization Factor/Cofilin (ADF/Cofilin) in the mouse forebrain modulates dendritic spine morphology, synaptic function, long-term potentiation (LTP), and learning and memory, but appear dispensable for the regulation of most forms of presynaptic plasticity. However, these analyses were performed in mice mutant for single members of these gene families, and thus the interpretation of these results is confounded by potential compensatory activity of homologous …

Regulation Of Glycogen Synthase Kinase 3 In The Pathophysiology And Treatment Of Mood Disorders, Abigail Marie Polter

All ETDs from UAB

Mood disorders are devastating psychiatric illnesses that will affect as many as one in every five persons worldwide over the course of their lifetime. Significant gaps still remain in our understanding of these illnesses and outcomes for many patients are far from optimal. Glycogen Synthase Kinase 3 (GSK3) is a protein kinase that is increasingly recognized as playing an important role in a number of neuronal functions, as well as in pathological states such as mood disorders. GSK3 is inhibited in the brain by phosphorylation on an N-terminal serine. Several treatments for mood disorders, including lithium, antidepressants, and atypical antipsychotics …

Heparanase Drives The Aggressive Myeloma Phenotype: Preclinical Development Of A Heparanase Inhibitor For The Treatment Of Multiple Myeloma, Joe Ritchie

All ETDs from UAB

Heparanase, an endoglycosidase which cleaves heparan sulfate chains at specific sites, is rarely expressed in normal tissues but becomes evident in many human cancers. We have previously shown that heparanase promotes myeloma growth and angiogenesis through modulation of the tumor microenvironment. Recognition that heparanase drives the aggressive myeloma phenotype has led to new strategies designed to therapeutically target this enzyme. SST0001, a non-anticoagulant heparin that is 100% N-acetylated and 25% glycol split, was previously described as a potent inhibitor of heparanase activity in vitro, and, in limited in vivo experiments, SST0001 was identified to have efficacy as an anti-tumor agent …

The Role Of Map Kinase Cascade In Msp Signaling Response, Youfeng Yang

All ETDs from UAB

The MSP domain is an evolutionarily conserved immunoglobulin-like structure of about 120 amino acids (Miller et al., 2001). A P56S missense mutation in the MSP domain of the human vapb gene is associated with a dominantly inherited form of Amyotropic Lateral Sclerosis (ALS) or Spinal Muscular Atrophy (SMA) (Nishimura et al., 2004). In C. elegans, secreted MSP binds to the VAB-1 Eph receptor and other receptors on oocyte and ovarian sheath cell surfaces (Miller et al., 2003). We have recently shown that the P56S mutation prevents secretion of the VAPB MSP domain, suggesting that the signaling function is important in …

Effect Of Overexpressing Apolipoprotein A-I In An Animal Model Of Alzheimer's Disease, Terry L. Lewis

All ETDs from UAB

Apolipoprotein A-I (apoA-I) is the major protein component of high density lipoprotein (HDL) in circulation and is expressed mainly by the liver and intestine. The levels of apoA-I/HDL are inversely related to the incidence of cardiovascular disease. Because of the connections between heart disease and Alzheimer's disease (AD), it is conceivable that high levels of apoA-I/HDL may be protective against AD. However, the limited literature shows mixed results on the role of apoA-I/HDL in the development of AD. It is hypothesized that increased expression of human apoA-I will ameliorate the behavioral deficits and characteristic amyloid-ß (Aß) plaque formation in a …

Protective Antibodies To The Proline-Rich And Alpha Helical Regions Of Pneumococcal Surface Protein A And Their Detection In An In Vitro Surrogate Assay, Calvin Clay Daniels

All ETDs from UAB

Current pneumococcal vaccines containing pneumococcal capsular polysaccharide antigens protect against infection by pneumococci. However, this protection is limited to strains expressing the capsule types included in the vaccine. Since the introduction of these vaccines, the increase in incidence of infection by serotypes not targeted by the vaccine, a process called "serotype replacement," and the growing antibiotic resistance of replacement strains both stress the need for vaccines with broader protection. The alpha-helical region of a protein present on all clinical isolates of pneumococci, Pneumococcal Surface Protein A (PspA), elicits protective immunity. Downstream of the alpha-helical region is a highly conserved region …

Poxvirus Evolution: The Role Of Horizontal Gene Transfer, Mary Rebecca Odom

All ETDs from UAB

We have investigated the set of all poxvirus proteins for information about the origins of protein coding genes of the Poxviridae family of viruses. A global assessment of all poxvirus proteins for levels of similarity to proteins of other organisms, including eukaryotes, viruses, and prokaryotes, has suggested trends and relationships informative about poxvirus evolution and poxvirus interactions with hosts. Our research has focused on the poxvirus proteins subset this assessment identified as likely to have evolutionary histories involving horizontal gene transfer (HGT). We have used phylogenetic reconstructions to individually determine the sources of more than 70 horizontally transferred genes present …

The Globin Gene Family Of The Cephalochordate Amphioxus: Implications For Chordate Globin Evolution, Bettina Ebner, Georgia Panopoulou, Serge N. Vinogradov, Laurent Kiger, Michael C. Marden, Thorsten Burmester, Thomas Hankeln

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

The lancelet amphioxus (Cephalochordata) is a close relative of vertebrates and thus may enhance our understanding of vertebrate gene and genome evolution. In this context, the globins are one of the best studied models for gene family evolution. Previous biochemical studies have demonstrated the presence of an intracellular globin in notochord tissue and myotome of amphioxus, but the corresponding gene has not yet been identified. Genomic resources of Branchiostoma floridae now facilitate the identification, experimental confirmation and molecular evolutionary analysis of its globin gene repertoire.

Results

We show that B. floridae harbors at least fifteen paralogous globin genes, …

Comparison Of Mitotic Cell Death By Chromosome Fragmentation To Premature Chromosome Condensation, Joshua B. Stevens, Batoul Y. Abdallah, Sarah M. Regan, Guo Liu, Steven W. Bremer, Christine J. Ye, Henry H. Heng

Wayne State University Associated BioMed Central Scholarship

Abstract

Mitotic cell death is an important form of cell death, particularly in cancer. Chromosome fragmentation is a major form of mitotic cell death which is identifiable during common cytogenetic analysis by its unique phenotype of progressively degraded chromosomes. This morphology however, can appear similar to the morphology of premature chromosome condensation (PCC) and thus, PCC has been at times confused with chromosome fragmentation. In this analysis the phenomena of chromosome fragmentation and PCC are reviewed and their similarities and differences are discussed in order to facilitate differentiation of the similar morphologies. Furthermore, chromosome pulverization, which has been used almost …

The Role Of Synaptically Evoked Plateau Potentials In Retinogeniculate Development, Emily Dilger

Theses and Dissertations

We study the activity-dependent refinement of sensory systems by using the mouse retinogeniculate system as a model. Spontaneous retinal waves lead to robust excitatory post-synaptic activity in developing relay cells in the dorsal lateral geniculate nucleus (dLGN) of the thalamus and are reportedly needed to help guide the segregation of retinal inputs into eye-specific domains as well as for the pruning of extraneous retinal inputs onto single dLGN relay cells. The composition of retinally evoked post-synaptic activity activated by these retinal waves in dLGN is largely unknown, but based on our in vitro recordings, such activity seems well suited to …

The Role Of The L-Type Calcium Channel And Its Carboxyl-Terminus, Miranda Jean Byse

University of Kentucky Doctoral Dissertations

In the heart, the primary role of the L-type calcium channel (LTCC) Ca_V1.2 is to conduct calcium into cardiomyocytes and initiate contraction. However, part of the Ca_V1.2 channel itself, the cleaved carboxyl-terminus (CCt) can also localize to the nucleus and regulate gene transcription. Therefore, the goal of this dissertation project was to determine the role and regulation of CCt in the embryonic and adult heart. The global hypothesis of my dissertation project is that CCt localizes to the nucleus in embryonic and adult cardiomyocytes via a calcium-mediated mechanism and regulates transcription. A model of pharmacological LTCC …

Neural Mechanisms Of Sympathetic Activation During Hyperinsulinemia And Obesity-Induced Hypertension, Megan Elyse Bardgett

University of Kentucky Doctoral Dissertations

Obesity afflicts more than 30% of the U.S. population and is a major risk factor for the development of hypertension, type II diabetes, and cardiovascular disease. Studies in humans and animals indicate that obesity is associated with increased sympathetic outflow to the vasculature and kidneys. One mechanism postulated to underlie the increase in sympathetic nerve activity (SNA) in obesity is hyperinsulinemia. Little is known regarding the central circuitry underlying elevated SNA and arterial blood pressure (ABP) during hyperinsulinemia and obesity or if sympathoexcitatory circuits are still responsive to insulin in obesity.

Hyperinsulinemic-euglycemic clamps elevate SNA to the hind limb vasculature …

Explorations In Homeoviscous Adaptation And Mass Spectral Analysis Of Membrane Lipids, Michael Douglas Timmons

University of Kentucky Doctoral Dissertations

The focus of this dissertation is centered on the mass spectral analysis of lipids and changes occurring in keeping with the concept of homeoviscous adaptation [1]. Homeoviscous adaptation is the process of modification of membrane lipids in response to environmental stimuli [1]. Dissertation investigations applied this concept to prokaryotic and eukaryotic organisms, and expanded the perception of environmental factors from exogenous organic solvents to intracellular environment.

The field of lipidomics deals with the analysis of phospholipid and fatty acid components of membranes the changes that occur due to environmental stimuli and their biological significance [2-6]. The high sensitivity of mass …

Local Synaptic Network Interactions In The Dentate Gyrus Of A Cortical Contusion Model Of Posttraumatic Epilepsy, Robert F. Hunt Iii

University of Kentucky Doctoral Dissertations

Posttraumatic epilepsy is a common consequence of brain trauma. However, little is known about how long-term changes in local excitatory and inhibitory synaptic networks contribute to epilepsy after closed-head brain injury. This study adapted a widely used model of experimental brain injury as a mouse model of posttraumatic epilepsy. Behavioral seizure activity and alterations in synaptic circuitry in the dentate gyrus were examined in mice after experimental cortical contusion brain injury. Spontaneous behavioral seizures were observed in 20% of mice after moderate injury and 36-40% of mice weeks after severe injury. In the dentate gyrus, most mice displayed regionally localized …

Studies Of The Effects Of Dopamine Neuron Stimulating Peptides In Rodent Models Of Normal And Dysfunctional Dopaminergic Systems, Joshua Lee Fuqua

University of Kentucky Doctoral Dissertations

A theoretical post-translational processing model of the proprotein form of glial cell line-derived neurotrophic factor (GDNF) likely produces three biologically active peptides. The three prospective peptides formed are 5, 11, and 17 amino acid peptides, entitled dopamine neuron stimulating peptide -5 (DNSP-5), -11 (DNSP-11), and -17 (DNSP-17), respectively. The DNSPs were hypothesized to increase dopaminergic neuron function because of their relationship to GDNF: a molecule with established neurotrophic actions on dopaminergic neurons. The DNSPs have the potential to provide a therapeutic molecule similar to GDNF, but with increased ease of delivery and improved bioavailability.

Neurochemical effects of DNSPs were examined …

Development Of Novel Ahr Antagonists, Hyosung Lee

University of Kentucky Doctoral Dissertations

Aryl hydrocarbon receptor (AHR) is a sensor protein, activated by aromatic chemical species for transcriptionally regulating xenobiotic metabolizing enzymes. AHR is also known to be involved in a variety of pathogenesis such as cancer, diabetes mellitus, cirrhosis, asthma, etc. The AHR signaling induced by xenobiotics has been intensively studied whereas its physiological role in the absence of xenobiotics is poorly understood. Despite a number of ligands of AHR have been reported thus far, further applications are still hampered by the lack of specificity and/or the partially agonistic activity. Thus, a pure AHR antagonist is needed for deciphering the AHR cryptic …

Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden

Articles

Salmon calcitonin (sCT) was conjugated via cysteine-1 to novel combed-shaped end-functionalised poly(PEG) methyl ether methacrylate) (sCT-P) comb-shaped polymers, to yield conjugates of total molecular weights (MW) inclusive of sCT: 6.5, 9.5, 23 and 40 kDa. The conjugates were characterised by HPLC and their in vitro and in vivo bioactivity was measured by cAMP assay on human T47D cells and following intravenous (i.v.) injection to rats, respectively. Stability against endopeptidases, rat serum and liver homogenates was assessed. There were linear and exponential relationships between conjugate MW with potency and efficacy respectively, however the largest MW conjugate still retained 70% of E …

Impact Of Static Stretch And Muscular Contractions On Force Production Within The Human Triceps Surae Muscle-Tendon Complex, Anthony D. Kay

Theses: Doctorates and Masters

Pre-performance routines commonly include stretching and intense muscular contractions in an attempt to optimise muscular performance and reduce injury risk. However, the isolated and combined effects of stretching and muscle contractions on neuromuscular performance are not well described. The aims of this research were to examine the effects of acute static stretch and intense muscular contractions on force production of the human plantarflexors and to examine possible mechanical and neuromuscular mechanisms underpinning any changes. Techniques including isokinetic dynamometry, electromyography (EMG), sonography and motion analysis were used in three studies on recreationally active human volunteers (n=20). In the first study, three …

Anomalous Constitutive Src Kinase Activity Promotes B Lymphoma Survival And Growth, Jiyuan Ke, R. Lakshman Chelvarajan, Vishal Sindhava, Darrell A. Robertson, Lazaros Lekakis, C. Darrell Jennings, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Previously we have shown that B cell receptor (BCR) expression and B cell receptor signaling pathways are important for the basal growth of B lymphoma cells. In particular we have shown that the activation of Syk, a non-src family protein tyrosine kinase and the mitogen activated protein kinases (MAPK), ERK and JNK that mediate BCR signals are required for the constitutive growth of B lymphoma cells. Since src family protein tyrosine kinases (SFKs) like Lyn are known to be needed for the phosphorylation of BCR co-receptors, Ig-alpha and Ig-beta, we hypothesized that one or more SFKs will be constitutively …

Gbdr Regulates Pseudomonas Aeruginosa Plch And Pchp Transcription In Response To Choline Catabolites, Matthew J. Wargo, Tiffany C. Ho, Maegan J. Gross, Laurie A. Whittaker, Deborah A. Hogan

Dartmouth Scholarship

Pseudomonas aeruginosa hemolytic phospholipase C, PlcH, can degrade phosphatidylcholine (PC) and sphingomyelin in eukaryotic cell membranes and extracellular PC in lung surfactant. Numerous studies implicate PlcH in P. aeruginosa virulence. The phosphorylcholine released by PlcH activity on phospholipids is hydrolyzed by a periplasmic phosphorylcholine phosphatase, PchP. Both plcH gene expression and PchP enzyme activity are positively regulated by phosphorylcholine degradation products, including glycine betaine. Here we report that the induction of plcH and pchP transcription by glycine betaine is mediated by GbdR, an AraC family transcription factor. Mutants that lack gbdR are unable to induce plcH and pchP in media …

Germinal Center Reutilization By Newly Activated B Cells., Tanja A Schwickert, Boris Alabyev, Tim Manser, Michel C Nussenzweig

Department of Microbiology and Immunology Faculty Papers

Germinal centers (GCs) are specialized structures in which B lymphocytes undergo clonal expansion, class switch recombination, somatic hypermutation, and affinity maturation. Although these structures were previously thought to contain a limited number of isolated B cell clones, recent in vivo imaging studies revealed that they are in fact dynamic and appear to be open to their environment. We demonstrate that B cells can colonize heterologous GCs. Invasion of primary GCs after subsequent immunization is most efficient when T cell help is shared by the two immune responses; however, it also occurs when the immune responses are entirely unrelated. We conclude …

Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil A. Shneider, Meghan N. Brown, Courtney A. Smith, James Pickel, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Gamma motor neurons (γ-MNs) selectively innervate muscle spindle intrafusal fibers and regulate their sensitivity to stretch. They constitute a distinct subpopulation that differs in morphology, physiology and connectivity from α-MNs, which innervate extrafusal muscle fibers and exert force. The mechanisms that control the differentiation of functionally distinct fusimotor neurons are unknown. Progress on this question has been limited by the absence of molecular markers to specifically distinguish and manipulate γ-MNs. Recently, it was reported that early embryonic γ-MN precursors are dependent on GDNF. Using this knowledge we characterized genetic strategies to label developing γ-MNs based on GDNF receptor expression, …

Structural Characterization Of The C-Terminus Of The Cochlear Motor Protein Prestin: Intrinsic Disorder Linked To Voltage Sensor Function, Michael S. Podgorski

Theses and Dissertations (ETD)

The sensitivity of mammalian hearing relies upon the ability to amplify sound. Outer hair cells (OHCs) in the cochlea have motile properties that support this function. The motor protein called prestin resides in the lateral wall of the OHCs. Prestin undergoes voltage-dependent conformational changes, which correlates to the movement of charge through the membrane or non-linear capacitance (NLC). This property underlies OHC electromotility. A mechanistic understanding of prestin’s function remains unknown. Previous research has tied prestin’s C-terminus (residues 499-799) to the voltage-dependent events that occur in the membrane. The folding and biochemical properties of prestin’s C-terminus were characterized. This information …

Altered Regulation Of Contraction-Induced Akt/Mtor/P70s6k Pathway Signaling In Skeletal Muscle Of The Obese Zucker Rat, Anjaiah Katta, Sunil K. Kakarla, Miaozong Wu, Satyanarayana Paturi, Murali K. Gadde, Ravi K. Arvapalli, Madhukar Babu Kolli, Kevin M. Rice, Eric R. Blough

MIIR Faculty Research

Increased muscle loading results in the phosphorylation of the 70 kDa ribosomal S6 kinase (p70S6k), and this event is strongly correlated with the degree of muscle adaptation following resistance exercise. Whether insulin resistance or the comorbidities associated with this disorder may affect the ability of skeletal muscle to activate p70S6k signaling following an exercise stimulus remains unclear. Here, we compare the contraction-induced activation of p70S6k signaling in the plantaris muscles of lean and insulin resistant obese Zucker rats following a single bout of increased contractile loading. Compared to lean animals, the basal phosphorylation of p70S6k (Thr389; 37.2% and Thr421/Ser424; 101.4%), …