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Analysis Of The Structural And Kinetic Properties Of Sult2a1 Induced By The Binding Of 3'-Phosphoadenosine-5'-Phosphosulfate, Ian Thomas Cook

All ETDs from UAB

Sulfation is an important Phase II drug metabolism reaction catalyzed by the cytosolic sulfotransferases (SULTs). SULT2A1 is a major SULT in liver and adrenal cortex that has been reported to sulfate a wide variety of substrates including bile acids, steroids, and drugs. The crystal structures of SULT2A1 suggest that PAPS binding causes a structural change. This study examines the kinetic changes in SULT2A1 caused by PAPS binding using computer modeling, enzyme kinetics, binding studies, and mammalian cells expressing SULT2A1. The data presented clearly demonstrate that the binding of PAPS changes the affinity of some substrates to SULT2A1 resulting in different …

Understanding Molecular Mechanisms Of Breast Cancer Metastasis Using Genetically-Engineered Mice, Leah M. Cook

All ETDs from UAB

Morbidity and mortality of breast cancer patients are drastically increased when primary tumor cells metastasize to distant organ sites. Effective treatment of metastatic disease has been limited; therefore, an increased molecular understanding to identify biomarkers and therapeutic targets is needed. Breast cancer metastasis suppressor 1 (BRMS1) suppresses development of metastases when expressed in a variety of cancer types, including metastatic mammary carcinoma. Little is known of Brms1 function throughout the initiation and progression of mammary carcinoma. Thus Brms1 transgenic mice (derived on C57BL/6 background) were generated by utilizing MMTV promoter expression (for mammary-selective overexpression) or the beta-actin promoter (for ubiquitous …

Structural And Mechanistic Studies On Er Upr Sensor Perk And Mitochondrial Translocon Element Tim44, Wenjun Cui

All ETDs from UAB

The unfolded protein response is one mechanism utilized by endoplasmic reticulum (ER) to maintain the homeostasis between ER protein folding machinery and ER proteins. UPR is induced by three ER transmembrane sensors: IRE1, ATF6 and PERK. PKR-like ER kinase (PERK) can sense the ER stress signal through its luminal domain to activate its cytoplasmic kinase domain catalytic activity. PERK kinase domain belongs to the eIF2α family. Members in this family are activated after being autophosphorylated at their activation loops and then specifically phosphorylate eIF2α at its Ser51 position. Phosphorylation of eIF2α can shutdown the cytosol protein translation from the initiation …

Characterization Of Tbx20 Isoforms And Protein Interactions In Heart Development, Paige Debenedittis

All ETDs from UAB

Proper cardiogenesis is critical for the development of vertebrates. Abnormalities in cardiogenesis can lead to congenital heart defects (CHDs), which occur in approximately 1% of live births. The cardiac transcription factor network contains different transcription factor families which direct the expression of critical cardiac genes. Determining how the cardiac transcription factors are regulated will provide insight in the mechanisms of cardiogenesis and CHDs. The T-box (TBX) transcription factor family is an ancient gene family important for development. Several TBX genes are expressed within the developing heart and play critical roles in differentiation, proliferation, and morphogenesis. One important TBX protein is …

Limited Transplantation Of Antigen-Expressing Hematopoietic Stem Cells Induces Long-Lasting Cytotoxic T Cell Responses And Effect Of Altered Suppressive Myeloid Population On Hiv-Disease Progression, Warren L. Denning

All ETDs from UAB

While each type of cancer and chronic viral infection has its own specific pathology, they share two common mechanisms of immune evasion. The first mechanism is the exhaustion or deletion of antigen-specific T cells. The second mechanism is the formation of an immunosuppressive environment responsible for the block of T cell function. Elicitation of antigen-specific T cells be accomplished by immunotherapy in place of conventional treatments such as HAART and chemotherapy. In addition, immunotherapy can alleviate the side-effects associated with long-term use of conventional therapies while reducing the total cost. The results presented here provide an alternative to conventional methods …

Role Of The Cardiomyocyte Circadian Clock In Modulating Myocardial Physiology And Pathophysiology, David Joseph Durgan

All ETDs from UAB

It is well established that multiple parameters of cardiovascular physiology and pathophysiology exhibit diurnal variations. For example, human heart rate and blood pressure peak during the morning and trough in the evening. Similarly, there is a morning prevalence for the onset of multiple adverse cardiovascular events, including myocardial ischemia, arrhythmias, and sudden cardiac death. Traditionally these rhythms have been attributed to rhythms in neurohumoral stimulation. However recent identification of the circadian clock mechanism in cardiovascular relevant cell types, including the cardiomyocyte, has prompted investigation into its role in modulating myocardial physiology and pathophysiology over the course of the day. Preliminary …

Molecular Mechanisms Regulating Caenorhabditis Elegans Sperm Migration, Johnathan Wesley Edmonds

All ETDs from UAB

Fertilization is the process by which male and female gametes join to give rise to a new organism. Union of sperm and ova requires that sperm be able to successfully locate and migrate towards oocytes in the female reproductive tract. By analyzing the in vitro migration of sperm from diverse species and mapping the complex architecture of their female reproductive tracts, we can infer that sperm must respond to directional cues to seek out the mature oocyte. However, the internal fertilization schemes of most complex animals complicate the analysis of in vivo sperm migration. The transparent epidermis of the nematode …

Biological Characterization Of Transmitted Human Immunodeficiency Virus Type-1, Tara Grant Edmonds

All ETDs from UAB

Heterosexual transmission of human immunodeficiency virus type&ndash1 (HIV&ndash1) accounts for the majority of infections worldwide, with women representing the larger percentage of infected individuals. The events leading to the transmission of HIV&ndash1 at mucosal surfaces are not well defined. Based on the observations that transmitted viruses nearly exclusively utilize the CCR5 coreceptor, and that in 80% of heterosexual transmissions a single virus variant establishes infection, there appears to be a selection mechanism that allows only a subset of viruses to be transmitted. This genetic bottleneck suggests that transmitted viruses may possess specific phenotypic and/or genotypic properties that allow for their …

The Role Of The Classical Nf-Kb Pathway In Hsc Self-Renewal And Acute Myeloid Leukemia, Robert Jason Flynn

All ETDs from UAB

Acute myeloid leukemia (AML) comprises approximately 25% of newly diagnosed cases of leukemia each year. The constitutive activation of the classical NF-κB signaling pathway has been observed in up to 70% of AML cases, and could be due to mutations upstream involving the PI3K-Akt cascade, which is also constitutively active in a majority of cases. In mice, constitutive activation of Akt either through deletion of the negative regulator of PI3K-Akt, PTEN, or by expression of Myr-Akt induces rapid stem cell loss along with a lethal, transplantable myeloproliferative disorder and AML. These studies show that constitutive Akt and NF-κB signaling distinguish …

Expanding Genetic Analysis Of Patients With A Neurofibromatosis Type 1-Like Phenotype, Emily Spencer

All ETDs from UAB

Neurofibromatosis Type 1, a common autosomal dominant disorder with neuro-cardio- facio-cutaneous presentation, is caused by mutations in the NF1 gene, a negative regulator of RAS-MAPK signaling. The presentation of NF1 is overlapping, yet clinically distinct from other diseases of RAS-MAPK signaling. An RNA-based comprehensive approach for mutation detection identifies an NF1 alteration in over 95% of non-founder NF1 patients with a classical NF1 presentation. However, no NF1 mutation was identified in 54.2% of the 2432 patients referred for molecular diagnostics due to the presence one or more NF1 related sign between August 2003 and July 2007. In order to clarify …

Calcium Dynamics Of Glial Cells And Genetic Influences On Behavior Of The Nematode Caenorhabditis Elegans, Randy Franklin Stout

All ETDs from UAB

A major challenge in neuroscience is understanding how the different neural cell types work together to process information and produce a behavioral output. Glial cells of the human brain have long been thought to act as support for the fundamental cell to cell communication at the core of cognition: neuronal synaptic communication. Research over the past several decades measuring glial activity and experimentally controlling glial cells in rodent model systems has shown that the two macroglia sub-types of glial cells (astrocytes and oligodendrocytes) have active roles in establishment, maintenance, and modulation of synaptic communication in the mammalian brain. Much of …

The Role Of Protein Folding And Protein Trafficking In Human Disease, Cristy Davette Tower-Gilchrist

All ETDs from UAB

This dissertation documents my findings in two unrelated projects. Project 1: Expansion of CAG repeats encoding glutamine in huntingtin and ataxin 3 causes the neurodegenerative diseases Huntington's disease (HD) and spinocerebellar ataxia 3 (SCA3), respectively. Both poly-glutamine (polyQ) expanded proteins misfold and ag-gregate within the cell. Preventing aggregation of polyQ proteins through molecular or pharmacological approaches provide therapeutic advantage in animal models of HD and SCA3. I hypothesized that the UL97 kinase encoded by the human cytomegalovirus (HCMV) may be able to prevent the aggregation of polyQ proteins. Initially, I showed that the UL97 kinase prevents the deposition of aggregates …

Effects Of Estrogen On Hippocampal Function In Young Adult And Aged Female Rats, Lindsey Celeste Vedder

All ETDs from UAB

In rodents, the ovarian estrogen 17b-estradiol (E2) is a potent modulator of hippocampal function and the hippocampus is critical for many types of learning and memory. Specifically, E2 increase the magnitude of long-term potentiation (LTP) at CA3-CA1 synapses, the density of dendritic spines in CA1 pyramidal cells and current mediated by NR2B-containing NMDA receptors. The E2-induced increase in LTP further requires NR2B-containing NMDARs. While considered a cellular correlate of learning and memory, enhanced LTP does not always predict enhanced learning. The first goal of this dissertation was to investigate the relationship between E2-enhanced LTP and learning and memory in young …

Strategies For Combined Screening And Imaging Of Breast Cancer, Jason Morgan Warram

All ETDs from UAB

Successful treatment of breast cancer directly correlates with tumor stage and grade at diagnosis. Early diagnosis leads to a five-year relative survival rate of 96.8% as opposed to only a 22.5% five-year survival rate when diagnosed at late stage. Cancer-specific mechanisms need to be extended to enable cancer detection in an individual patient, in particular, the metastatic burden that currently cannot be assessed by conventional imaging. This approach for cancer detection would remove the biases of patient characteristics, permit immediate diagnostic feedback, improve sensitivity for early detection of small metastatic lesions, and be cost effective. Toward this goal, the cancer-specific …

The Requisite Role Of Dectin-1 And Il-17 In Innate Host Defense Against Aspergillus Fumigatus, Jessica L. Werner

All ETDs from UAB

Immune suppression increases the incidence of invasive fungal infections, particularly those caused by the opportunistic mold Aspergillus fumigatus. We show that non-immunosuppressed mice lacking the beta-glucan receptor Dectin-1 (Dectin-1-/-) are more susceptible to intratracheal challenge with A. fumigatus than control mice, exhibiting >80% mortality within 5 days; ultimately attributed to a compromise in respiratory mechanics. In response to A. fumigatus challenge, Dectin-1-/- mice demonstrated impaired inflammatory response as seen through defective cytokine and chemokine production, which resulted in insufficient lung neutrophil recruitment and uncontrolled A. fumigatus lung growth. Alveolar macrophages from Dectin-1-/- mice failed to produce proinflammatory mediators in response …

Ecology And Transmission Of Eastern Equine Encephalitis Virus In The Southeastern United States, Gregory Scott White

All ETDs from UAB

The virus Eastern Equine Encephalitis virus (EEEV) is a highly pathogenic arthropod-borne virus (arbovirus) present in the US. The virus is listed as a reportable illness to the Centers of Disease Control and Prevention (CDC) and is also listed as a select agent by Human Health and Services (HHS). Studies on EEEV starting back in the 1930's have determined many important facets of the ecology, transmission and evolution of the virus. It is understood that in many endemic foci, the mosquito Culiseta melanura is the primary enzootic vector of the virus. EEEV is thus maintained in an enzootic cycle between …

Functional Interplay Between Trans Factors And Cis-Elements That Govern Il17a&F Transcription, Sarah Kern Whitley

All ETDs from UAB

Protective immunity against a variety of infections depends on the amplification and differentiation of naïve antigen-specific CD4 T cells. T helper 17 (Th17) cells are important for defending mucosal barriers from invading extracellular bacterial pathogens. This effector CD4 lineage is characterized by production of the cytokines IL-17A, IL-17F, IL-21, and IL-22, which elicit influx of inflammatory cells to promote pathogen clearance. The cytokines IL-6 and TGF&beta are the principal factors that initiate Th17 lineage development, and the STAT3-inducing cytokines IL-21 and IL-23 assist and/or maintain the Th17 developmental program. Recently, an additional cytokine has been demonstrated to encourage Th17 differentiation: …

The Role Of Protease-Activated Receptor-1 In Synaptic Plasticity And Memory, Antoine Gabriel Almonte

All ETDs from UAB

Protease-activated receptor-1 (PAR1) is an unusual G-protein coupled receptor (GPCR) that is activated through proteolytic cleavage by extracellular serine proteases. While previous work has shown that inhibiting PAR1 activation is neuroprotective in models of ischemia, traumatic injury, and neurotoxicity, surprisingly little is known about PAR1's contribution to normal brain function. In the central nervous system (CNS), PAR1 is expressed in glial cells in the hippocampus, a brain region critical for memory formation. I am particularly interested in PAR1 because its activation enhances the function of N-methyl-D-aspartate receptors (NMDARs), which are required for some forms of behavioral learning and synaptic plasticity. …

The Effect Of Sulfasalazine On Functional Recovery And Neuropathic Pain Following Spinal Cord Injury, Kelly Dunham Atkins

All ETDs from UAB

Spinal cord injury (SCI) is a devastating condition resulting in loss of motor function as well as sensory abnormalities. Insight into the pathophysiology of SCI progression has been gained through use of pre-clinical animal models, however these have not been successful in yielding pharmacological interventions for clinical management of SCI. One proposed reason for this discrepancy may be the use of SCI models which are not fully clinically relevant and do not assess the contribution of gray matter pathology to SCI functional outcomes. Post-SCI inflammation is well-documented and may lead to downstream loss of motor function. Additionally, inflammation is thought …

Ampa Receptor Trafficking In Schizophrenia, John Hammond

All ETDs from UAB

The glutamate hypothesis of schizophrenia is based primarily on NMDA receptor dysfunction. Recent studies have led to an expansion of this hypothesis to include AMPA receptors which are essential for neurotransmission through NMDA receptors. Examination of total AMPA receptor protein expression in schizophrenia has been inconsistent and led to examination of AMPA receptor interacting proteins and trafficking and subcellular localization of the receptors. AMPA receptors are highly trafficked from the endoplasmic reticulum to the synapse and in a complex system of endosomes. Alterations in the subcellular localization of these receptors may be a part of the underlying pathophysiology of schizophrenia. …

Bone Morphogenetic Protein Signaling Pathways During Mouse Heart Development: Roles For Chd7 And Mycn, Cristina Harmelink

All ETDs from UAB

Bone Morphogenetic Protein (BMP) signaling pathways are imperative for proper heart development. BMP ligands bind serine threonine kinase receptors, which activate intracellular receptor-regulated SMAD proteins. SMAD1, SMAD5, and SMAD8 transduce BMP signals from the cytoplasm to the nucleus, where they regulate transcription. We have investigated two aspects of BMP signaling during mouse cardiogenesis: identifying SMAD1-interacting proteins and exploring the roles of a known BMP target, Mycn, in the developing myocardium. Chromodomain helicase DNA binding protein 7 (CHD7) is a highly conserved transcription factor that promotes protein synthesis, proliferation, and differentiation. Haploinsufficiency for CHD7 causes CHARGE syndrome, a developmental disorder characterized …

The Study Of Intracellular Signaling Pathways In Schizophrenia, Adam Funk

All ETDs from UAB

INTRACELLULAR SIGNALING AND INTEGRATION ABNORMALITIES IN SCHIZOPHRENIA Adam J. Funk DEPARTMENT OF NEUROBIOLOGY ABSTRACT The pathophysiology of schizophrenia is complex and diverse, with many classes of receptors, neurotransmitters, and brain regions implicated in this illness. The many hypotheses proposed have yet to fully explain the heterogeneity of the genetic, postmor-tem, and clinical evidence. It is the goal of this dissertation to integrate the current hy-potheses of schizophrenia into a unified hypothesis of abnormal intracellular signaling and signal integration. Inconsistencies in genetic and postmortem findings suggest that the development of schizophrenia is multifaceted, and the heterogeneity of symptoms supports the hypothesis …

The Role Of Tgf-Ss Receptors In The Induction Of Mucosal Tolerance, Rebekah Sims Gilbert

All ETDs from UAB

Oral tolerance, defined as the immunologic state of systemic and mucosal unresponsiveness to an antigen, is an essential function of the mucosal immune system. Although antigen presentation has been found to play an important role in oral tolerance, T cells are known to be the effector immune cells that perpetrate this state. Recent studies found that antigen-specific T regulatory (Treg) cells are important in the induction and maintenance of oral tolerance. The extrathymic development of these Tregs depends on the presence of TGF-ß1 during the differentiation process. However, it has also been shown that oral tolerance could be induced in …

Human Cytomegalovirus Ul97 Kinase Activity Modifies Cell Cycle Checkpoint Regulators, Rachel Brooke Gill

All ETDs from UAB

Human cytomegalovirus (CMV) infection results in destructive infections in neonates and immunocompromised individuals. Being the primary congenital infection in the United States, it can often result in permanent neurological deficits in infants. The current therapies for CMV infections all target the viral DNA polymerase and also have dose-limiting toxicities. Isolates resistant to ganciclovir (GCV), the therapy of choice, can sometimes overwhelm immunocompromised hosts. Better therapies for this infection are required. The CMV UL97 kinase is a key enzyme in the treatment of CMV infection because it phosphorylates GCV. Additionally, maribavir (MBV) specifically inhibits UL97 kinase activity and inhibits viral replication. …

Oxidative Stress And Xanthine Oxidase In Acute And Chronic Cardiac Volume Overload In Rats, James Douglas Gladden

All ETDs from UAB

Mechanisms of left ventricular dysfunction in cardiac volume overload (VO) are not well understood and there is no medical therapy. 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 xanthine oxidase (XO) plays 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 and then depressed by 6 weeks. …

The Sodium-Potassium-Chloride Cotransporter In Glioma Biology, Brian R. Haas

All ETDs from UAB

The most common malignant primary brain tumor, gliomas usually derive from glial cells including oligodendrocytes and astrocytes. These tumors are characterized by high rates of proliferation and aberrant migration which make them notoriously difficult to treat using standard treatment paradigms such as chemotherapy and radiation. In order for glioma cells to migrate into the surrounding brain tissue, they must undergo rapid and dynamic volume changes. Previous work published by the Sontheimer laboratory and others indicates glioma utilize the flux of ions across the cell membrane to aid in volume changes associate with cell migration. In this dissertation, I show the …

Human Cytosolic Sulfotransferase 2b1b: Structure, Function And Expression In Human Brain, Emily D. Salman

All ETDs from UAB

The human cytosolic sulfotransferases are a family of phase II drug-metabolizing enzymes that conjugate a sulfonate moiety from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to a hydroxyl moeity on a substrate. SULT2B1b catalyzes the sulfation of hydroxysteroids as well as many xenobiotics; and is expressed extra-hepatically. SULT2B1b is a unique SULT because it has amino (N)- and carboxy (C)-terminal peptide extensions, undergoes post-translational modification, and is localized in both the cytosol and nucleus. Analysis of SULT2B1b revealed that the N- and C-terminal extensions of SULT2B1b are predicted to be intrinsically unstructured peptides. Size exclusion chromatography has revealed that SULT2B1b is enzymatically active as …

Altered Leptin Signaling On Dendritic Cells As A Potential Mechanism For Cancer Immunotherapy, Lorena Y. De Los Santos

Open Access Theses & Dissertations

Leptin is a pleiotropic hormone synthesized primarily by white adipocytes and its receptors are expressed in a variety of tissues and cells such as in the hypothalamus and cells of the immune system. Multiple cell types can produce a considerable amount of leptin such as skeletal muscle, placenta, and osteoblasts to name a few and its synthesis has been shown to be regulated by sex hormones and a broad range of inflammatory mediators. Although leptin has been shown to directly affect immune response, we are interested in how leptin affects dendritic cell function and their ability to induce a proper …

Development Of A Novel Metallo-Lipid Microparticle Delivery System For A Leishmania Mexicana Dna Vaccine Candidate, Joanna B. Valencia

Open Access Theses & Dissertations

ABSTRACT

Background and Significance.

The leishmaniases are an important group of neglected tropical parasitic diseases caused by parasitic protozoa of the genus Leishmania. International health authorities estimate that 350 million people around the world are at risk for contracting leishmaniasis. Two million new cases occur each year and 12 million people are presently infected worldwide. Leishmaniasis is endemic throughout the Americas region including all of Central America, most of South America, Mexico and southern Texas. Leishmania is also considered a threat to the military readiness of U.S. troops deployed to the Middle East or Latin America.

First- and second-line treatments …

Protein Kinase C Δ Is Critical For Nucleotide Excision Repair Of Cyclobutane Pyrimidine Dimers, Christopher Michael Negro

Master's Theses

Nucleotide excision repair (NER) is the process by which cells identify and repair bulky, helix-distorting DNA lesions such as ultraviolet (UV) radiation-induced cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PP). NER in human cells is a complex biochemical process requiring several complementation groups. Defects in complementation group genes result in rare, autosomal recessive cancer syndromes such as xeroderma pigmentosum (XP), cockayne syndrome (CS), and trichothiodystrophy, supporting the tumor suppressive effects of NER. Protein Kinase C delta (PKCδ) expression is lost in squamous cell carcinomas where it functions as a tumor suppressor gene. Additionally, in response to UV radiation, PKCδ is …