Medicine and Health Sciences Commons^™

Mouse Modeling Of Pancreatic Ductal Adenocarcinoma (Pdac); Search For Early Diagnostic Markers And Therapeutic Targets, Kyoko Kojima

All ETDs from UAB

PDAC is a highly malignant neoplasm that carries a very poor prognosis. PDAC development is a multistage transformation process that involves multiple genetic alterations that include activation of EGFR/HER2 and KRAS, and loss-of-function mutations in INK4A/ARF, p53 and SMAD4. In recent years, several genetically engineered mouse models that accurately recapitulate human pancreatic neoplasia have been developed. Histological characterizations of those models have revealed possible roles for the mutated RAS, INK4a/ARF and p53 in pancreatic tumorigenesis. However, the role of SMAD4 mutation, which is associated with late stages of tumor progression, has yet to be explored. Additionally, those models that would …

Genome Copy Number Profiles Of African-American And European-American Early-Onset Breast Cancer, Tyesha Latrece Farmer

All ETDs from UAB

Breast cancer is the second leading cause of cancer related death among women in the United States, surpassed only by lung cancer. It is estimated that over 200,000 women developed breast cancer and more than 40,000 died of the disease in 2008 alone. Although the overall incidence of breast cancer is lower in African-American women, the incidence of early-onset breast cancer is higher than that observed in European-American women. African-American women also have higher mortality rates due to this disease than those observed in their European-American counterparts. Breast cancer exhibits heterogeneity at the molecular, cellular, and clinical levels, and the …

Determinants Of Growth Hormone Receptor Downregulation, Luqin Deng

All ETDs from UAB

Growth hormone (GH), a 22 kD polypeptide primarily produced in the anterior pituitary gland, is a key regulator of postnatal growth and affects carbohydrate, protein and lipid metabolism. Growth hormone receptor (GHR) is a single membrane-spanning type Ⅰ glycoprotein of the cytokine receptor family and is initially synthesized as a precursor and undergoes carbohydrate processing during transport through the Golgi. It has no intrinsic kinase activity. One molecule of GH binding to predimerized GHR on the cell surface induces the receptor conformational change activating the cytoplasmic domainassociated tyrosine kinase, Janus Kinase 2 (JAK2), which phosphorylates GHR, followed by the activation …

The Potential Role Of Vh Replacement In Editing And Generating Autoreactive Antibodies, Run Fan

All ETDs from UAB

VH replacement occurs through RAG-mediated secondary recombination between an upstream VH gene and an existing VHDJH joint. In the first part of this dissertation, we focused on the potential regulation of VH replacement in the human B lineage EU12 cells muHC+ population, which underwent spontaneous VH replacement during in vitro culture. We cloned one of the dominant IgH genes, A19H, expressed in the EU12 muHC+ cells, and generated recombinant antibodies. We found that these recombinant antibodies recognize SM antigens. The anti-SM reactivity of A19H can not be efficiently neutralized by a randomly selected group of fourteen IgL chains from healthy …

Insulin Signaling And Function In Osteoblasts, Keertik S. Fulzele

All ETDs from UAB

Insulin and insulin-like growth factor-1 (IGF-1) are evolutionarily conserved hormonal signaling pathways with structurally similar ligands and receptors. Recent stu-dies suggest that that insulin and IGF-1 exert distinct as well as overlapping functions to regulate different aspects of skeletal development. A major problem in distinguishing the actions of insulin and IGF-1 is the fact that the receptors are co-expressed in many cell types and each ligand is able to cross-activate the other ligands' receptor. To distinguish direct skeletal actions of insulin from that of IGF-1, we have conditionally disrupted each receptor in vitro and in vivo specifically in osteoblasts. Studies …

Regulation Of The Human Heme Oxygenase-1 Gene By Nitro-Linoleic Acid, Macienne M. Wright

All ETDs from UAB

Nitro-fatty acids (NO-FA) exert anti-inflammatory effects in the vasculature. Heme oxygenase-1 (HO-1) degrades heme into iron, biliverdin, and carbon monoxide and is up-regulated as an adaptive and protective response to inflammatory processes. This dissertation examined whether nitro-linoleic acid (LNO2) induced HO-1 gene expression and evaluated the molecular mechanism of induction in human aortic endothelial (HAEC), human embryonic kidney 293 (HEK 293) and mouse embryonic fibroblast (MEF) cells. LNO2 induced HO-1 mRNA and protein in HAEC at the level of transcription. NO scavenging by carboxy-PTIO partially reversed LNO2–mediated induction of HO-1, suggesting that LNO2 acts via NO-dependent and NO-independent mechanisms of …

Protective Mechanisms Of Apoa-I Mimetic Peptide Action In Sepsis-Induced Tissue Injury, Zhenghao Zhang

All ETDs from UAB

Sepsis is among the top ten causes of death in the US, and it is associated with severe inflammatory tissue damage and organ dysfunction. Reduced plasma high density lipoprotein (HDL) is associated with increased mortality in septic patients. Since raising plasma apolipoprotein (apo) A-I and HDL may reduce sepsis complications, we tested the hypothesis that the apoA-I mimetic peptide 4F confers similar protective effects in two animal models of sepsis, and explored the possible mechanisms. In endotoxemic rats, inflammatory mediators were significantly induced while blood pressure was significantly reduced by 6hr. The impaired arterial response to vasoconstrictors was related to …

Molecular Characterization Of Neural Apoptosis, Ken C. Walls

All ETDs from UAB

Neural cell death plays a critical role in normal nervous system development and dysregulated neural stem cell death contributes to brain malformation, tumorgenesis, and possibly, neurodegenerative disease. The two major forms of cell death in the nervous system are apoptotic and autophagic. Altered clearance of proteins may lead to neuronal dysfunction and neuron loss via apoptotic and/or autophagic pathways. The research presented here examined the molecular regulation of the autophagic and apoptotic pathways in vivo and in vitro by using models of lysosome dysfunction and hypoxia. In vivo investigation of lysosome dysfunction-induced death utilized the cathepsin D (CD)-deficient mouse model. …

A Functional Analysis Of The Human Immunodeficiency Virus, Sushma Jyotika Bhakta

All ETDs from UAB

The retroviral life cycle is separated into two distinct phases of infection. In the first phase, viral enzymes and proteins allow the virus to establish infection. The virus usurps host machinery in the second stage to produce infectious virus. In both phases of the replication cycle, the envelope (Env) glycoprotein (gp) is a key component of infectivity. Env plays a pivotal role in viral entry, by mediating attachment and facilitating fusion of the viral and cellular membranes, and during assembly, where Env must be incorporated into budding virions in order to produce infectious virions. The Env cytoplasmic domain (CD) interacts …

The Effects Of P-Glycoprotein Deficiency On Intestinal Integrity And Homeostasis, Elizabeth Marie Staley

All ETDs from UAB

THE EFFECTS OF P-GLYCOPROTEIN DEFICIENCY ON INTESTINAL INTEGRITY AND HOMEOSTASIS ELIZABETH M. STALEY MICROBIOLOGY ABSTRACT P-glycoprotein (P-gp) is an ATP-binding transmembrane pump associated with substrate extrusion in cells of epithelial and hematopoietic lineage. Polymorphisms in multidrug resistance genes (MDR), which encode this protein, are associated with development of inflammatory bowel disease in patient subsets. Furthermore, FVB/N animals deficient in P-gp expression develop spontaneous colitis. Disease in FVB.mdr1a-/- animals is reported to be the result of P-gp deficiencies in intestinal epithelial cells. We developed a neonatal model of bone marrow reconstitution to accurately evaluate the contribution of P-gp deficiencies in either …

Genetic Complexity And Population Diversity Of Plasmodium Falciparum In The Peruvian Amazon, Patrick Lee Sutton

All ETDs from UAB

GENETIC COMPLEXITY AND POPULATION DIVERSITY OF PLASMODIUM FALCIPARUM IN THE PERUVIAN AMAZON PATRICK LEE SUTTON MICROBIOLOGY GRADUATE PROGRAM ABSTRACT Characterizing the genetic complexity of immunologically relevant proteins, expressed during the life cycle of P. falciparum, is essential for identifying and advancing potential vaccine candidates. The current malaria immunity paradigm is rooted in high transmission studies which have investigated the impact of high genetic diversity on the development of humoral responses. Given the dynamic nature of malaria parasites, especially their ability to acclimate to change, it is likely that regions of low transmission do not share the same malaria immunity paradigm …

Regulation Of Tissue Remodeling Through The Calreticulin Binding Domain Of Thrombospondin-1, Mariya Ts'ana Sweetwyne

All ETDs from UAB

Thrombospondin-1 (TSP1) is a multifunctional matricellular protein released by platelets in response to injury and secreted by cells under stress. TSP1 is cleaved into functional N- and C-terminal domain fragments, which have paradoxical actions with respect to angiogenesis, cell survival, and cell adhesion. Wound healing studies by others demonstrated that TSP1 knockout mice have delayed rates of wound closure, which was attributed to actions of the C-terminal domain. We wished to investigate the specific role of the N-terminal domain in tissue remodeling. Previously, we established that a sequence (aa 17-35) in the N-terminal domain of TSP1 induces focal adhesion disassembly, …

The Role Of Gbf1 In Golgi Biogenesis And Secretory Traffic., Tomasz Szul

All ETDs from UAB

The secretory pathway within a cell consists of series of membrane compartments connected by shuttling secretory vesicles containing cargo that travel from endoplasmic reticulum (ER) though ER-to-Golgi intermediate compartment (ERGIC), the Golgi apparatus, and endosomal compartment to the plasma membrane (PM). The Golgi specific brefeldin A (BFA)-resistant factor 1 GBF1 has been identified as an important factor involved in traffic between ER and Golgi and within the Golgi apparatus. GBF1 belongs to a family of guanine nucleotide exchange factors (GEFs) that stimulate the exchange of GDP for GTP on small GTPases, ADP-ribosylation factors (ARFs). The exchange of the nucleotide activates …

Characterization Of The Induction And Regulation Of Early B Cell Development, Melissa Ann Thal

All ETDs from UAB

Hematopoiesis is a highly regulated process directed by the microenvironment or niche in the bone marrow and the transcription factors those signals activate. Gene knockout experiments have identified critical cytokine signals and transcription factors required for promoting the differentiation of a hematopoietic stem cell to a B cell, but the regulatory mechanisms have yet to be fully elucidated. In early B cell development, a transcriptional hierarchy exists wherein E2A proteins activate early B-cell factor (Ebf1), which in turn activates expression of the B cell commitment factor, Pax5. In our studies, we use IL-7 receptor alpha chain (IL-7Rα) knockout animals that …

Marginal Zone B-Cell Precursors As Cellular Agents For Type I Ifn Promoted Antigen Transport, John Hsien Wang

All ETDs from UAB

Type I IFN is a known pro-inflammatory cytokine that is associated with the development of systemic lupus erythematosus (SLE). At the level of B-cell regulation, current literature primarily attributes the formation of autoantibodies at the post-germinal center stage when type I IFN is known to promote plasmablast differentiation. However, our findings here point to a type I IFN effect at the pre-germinal stage. Type I IFN promotes T-dependent antibody response, activation-induced cytidine deaminase (AID) expression, germinal center formation, all of which are processes before the onset of plasmablast differentiation. We have determined a subset of splenic transitional B-cells, that is …

A Novel & Efficient Method To Produce High Titers Of Infectious Hpv In Organotypic Cultures Of Primary Human Keratinocytes, Hsu-Kun Wang

All ETDs from UAB

Infections by the high-risk human papillomavirus type 18 (HPV-18) or type 16 (HPV-16) can lead to cancers of the anogenital tract. Because the propagation of HPVs is restricted to differentiated human squamous epithelia, experimental studies of the productive program are conducted in organotypic cultures. The current methods are of low efficiency and time consuming and have relied on immortalized epithelial cell lines that do not support efficient viral DNA amplification or virion production, compromising HPV genetic analyses and obscuring normal virus-host cell interactions. I used Cre-loxP site-specific recombination to develop a relatively simple, fast and highly efficient system to produce …

Understanding The Regulatory Mechanisms Of Ubp-M And H2a Deubiquitination In Chromatin And Cellular Functions, Heui Yun Joo

All ETDs from UAB

Posttranslational modifications of histones regulate important chromatin and cellular functions. Among them, ubiquitination of histone H2A is correlated to transcriptional repression, such as HOX gene silencing and X chromosome inactiviation. Little was known about the removal of ubiquitin from histones, the enzyme(s) involved and its function in chromatin dynamics. We have identified the protein Ubp-M (USP16) to be the H2A- and nucleosome-specific deubiquitinase. We also demonstrated that Ubp-M-mediated H2A deubiquitination is involved in cell cycle progression to M-phase, HOX gene expression, and posterior development in Xenopus laevis. Furthermore, we have also purified USP12 and USP46 which contain an Ubp-M independent …

Regulation Of Vh Replacement In Human Immature B Cells By B Cell Receptor (Bcr) - Mediated Signaling, Jing Liu

All ETDs from UAB

VH replacement occurs through RAG-mediated secondary recombination to change unwanted IgH genes. In this dissertation, I focused on studying the molecular mechanism that regulates VH replacement in human immature B cells. In part I, our results show that VH replacement is regulated by B cell antigen receptor (BCR) mediated signaling. Using the human EU12 mHC+ cells as an experimental model system, crosslinking BCR with F(ab')2 anti-IgM antibodies results in BCR internalization, cell proliferation arrest, and induction of VH replacement. Pretreatment of human EU12 mHC+ cells with the protein tyrosine kinase inhibitor Genistein, Syk kinase inhibitors, and a Src kinase inhibitor …

Counterregulatory Roles Of Transforming Growth Factor (Tgf)-Beta And Atrial Natriuretic Peptide (Anp) In Pressure Overload-Induced Cardiac Remodeling And Fibrosis, Jason Anthony Lucas

All ETDs from UAB

Pressure overload stress (eg. hypertension or aortic stenosis) results in excessive cardiac fibrosis, changes in left ventricular (LV) geometry, and disruption of LV contractility, ultimately leading to heart failure. We hypothesize that transforming growth factor-beta (TGF-beta), a pro fibrogenic factor, and atrial natriuretic peptide (ANP), an anti fibrogenic factor, interact directly in a counterregulatory manner to balance the production of extracellular matrix (ECM) under pressure overload induced cardiac stress or hypoxia-induced pulmonary vascular adaptation. In this report, we examine structural and functional responses of the intact heart to pressure overload stress in vivo. We then utilize isolated rat pulmonary artery …

Mechanisms Of Growth Hormone Action In Skeletal Muscle, Mahendra Devaraj Mavalli

All ETDs from UAB

Growth hormone (GH) and insulin like growth factor-1 (IGF-1) exert profound growth promoting actions during pre and postnatal skeletal muscle development. GH and IGF-1 seem to promote their anabolic actions by influencing skeletal muscle cell prolif-eration and fusion. However, because GH stimulates the production of IGF-1 from the liver and other GH-responsive peripheral tissues, including skeletal muscle, the individual contributions of these two growth factors to anabolic responses in skeletal muscle remains poorly defined. In this dissertation research, I sought to distinguish the mechanisms responsible for growth hormone's (GH) anabolic actions in skeletal muscle. To accomplish this, I analyzed the …

Cystic Fibrosis Transmembrane Conductance Regulator (Cftr) Modulators And Their Mechanistic Basis: Relevance To Emerging Therapies For Cystic Fibrosis, Louise Clare Pyle

All ETDs from UAB

Cystic fibrosis (CF) is a lethal genetic disorder leading to pulmonary decline and premature death. The gene responsible for CF, the cystic fibrosis transmembrane conductance regulator (CFTR), serves as a chloride and bicarbonate channel situated at the apical cell surface of epithelia. The discovery of small molecules that augment channel gating of mutant CFTR (so-called `potentiators') represents a major theme of CF research, and offers hope for new therapeutic interventions. High-throughput screening (HTS) provides a means to test millions of agents in an unbiased manner for CFTR potentiating properties. New agents identified by HTS have undergone extensive pre-clinical and clinical …

The Role Of Mitochondria And Plasma Membrane Ca2+ Transport Systems In Ca2+-Dependent Glutamate Release From Rat Cortical Astrocytes, Reno Cervo Reyes

All ETDs from UAB

Astrocytes, a type of glial cell in the central nervous system, are recognized for their support roles to neurons. They supply neurons with metabolites, maintain ion homeostasis and clear the synaptic space of neurotransmitters. However, it has been found that some astrocytes have receptors for neurotransmitter and neuroligands, exhibit Ca2+ excitability when stimulated via these receptors, and secrete gliotransmitters as an output of this Ca2+ excitability. In the Ca2+-dependent release of glutamate, it has been shown that the endoplasmic reticulum is the predominant source and the extracellular space is the auxiliary source of free Ca2+ necessary for triggering exocytosis. Because …

Neuroinflammation And Fragile X Syndrome: Regulation By Glycogen Synthase Kinase-3, Christopher Joseph Yuskaitis

All ETDs from UAB

Neuroinflammation and Fragile X syndrome (FXS) are two particularly devastating neurologic conditions for which no adequate treatment exists and much is still unknown about the underlying cellular and molecular processes. Neuroinflammation contributes to the pathogenesis of many neurologic and psychiatric disorders, thus treatment of the underlying inflammation has broad implications. FXS is the most common cause of inherited intellectual and developmental delay and one of the few known genetic causes of autism. Neuroinflammation and FXS have potential links with glycogen synthase kinase-3 (GSK3) and its inhibitor, lithium. Therefore, the overall goal of this research was to examine the role of …

Diffusion Pathways Through The Outer Membrane Of Mycobacteria, Olga Danilchanka

All ETDs from UAB

The extraordinary capacity of Mycobacterium tuberculosis (Mtb) to adapt to environmental changes during infection contributes to its success as a pathogen. While the unique outer membrane (OM) of mycobacteria functions as a permeability barrier for toxic molecules, uptake of nutrients is required to sustain viability of Mtb. Whereas hydrophobic molecules can diffuse through membranes, uptake of small hydrophilic compounds is mediated by water-filled channels, porins. For example, Msp-like porins of M. smegmatis (Ms) were shown to be required for uptake of hydrophilic beta-lactam antibiotics, which are also known to diffuse through porins in gram-negative bacteria. Because the structure of the …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

The Interplay Between The Expression And Functions Of Wnt13 Isoforms During Apoptosis In Bovine Aortic Endothelial Cells, Tao Tang

University of Kentucky Doctoral Dissertations

Wnt proteins are crucial for development/homeostasis by controlling cell fate including apoptosis (Moon RT et al. 1997). Three humanWnt13 isoforms were identified: the secreted Wnt13A, mitochondrial Wnt13B, and nuclear Wnt13C forms; and nuclear Wnt13 had an increased sensitivity to LPS/TNF-induced apoptosis in primary endothelial cells (EC); both Wnt13B and C mRNA contain two start codons (AUG+1 and +74), but the same protein encoded from AUG+74 by Wnt13C was expressed lower than Wnt13B (Struewing IT et al.2006). We hypothesize that during EC apoptosis, the nuclear Wnt13C expression is regulated translationally; nuclear Wnt13 favors apoptosis through regulating the activity/expression of apoptosis-related factors; …

Low Density Lipoprotein Receptor And Alzheimers Disease, Rangaraj K. Gopalraj

University of Kentucky Doctoral Dissertations

Since apoE allele status is the predominant Alzheimers disease (AD) genetic risk factor, functional single nucleotide polymorphisms (SNPs) in brain apoE receptors represent excellent candidates for association with AD. Therefore, three low density lipoprotein receptor (LDLR) SNPs were evaluated by TaqMan allelic discrimination assays for association with AD and I found that certain haplotypes alter the odds of AD. A SNP within LDLR exon 12, rs688, was identified in silico as neutralizing a putative exon splicing enhancer (ESE). Since LDLR is a major apoE receptor in the brain, I hypothesized that rs688 modulates LDLR splicing in neural tissues and associates …

Development And Evaluation Of New Mask Protocols For Gene Expression Profiling In Humans And Chimpanzees, Donna M. Toleno, Gabriel Renaud, Tyra G. Wolfsberg, Munirul Islam, Derek E. Wildman, Kimberly D. Siegmund, Joseph G. Hacia

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Cross-species gene expression analyses using oligonucleotide microarrays designed to evaluate a single species can provide spurious results due to mismatches between the interrogated transcriptome and arrayed probes. Based on the most recent human and chimpanzee genome assemblies, we developed updated and accessible probe masking methods that allow human Affymetrix oligonucleotide microarrays to be used for robust genome-wide expression analyses in both species. In this process, only data from oligonucleotide probes predicted to have robust hybridization sensitivity and specificity for both transcriptomes are retained for analysis.

Results

To characterize the utility of this resource, we applied our mask protocols …

Characterization Of Nprc And Its Binding Partners, Abdel A. Alli

USF Tampa Graduate Theses and Dissertations

The C type natriuretic peptide receptor (NPRC) also known as NPR3 is a widely expressed single transmembrane-spanning protein. NPRC functions as a homodimer at the cell surface for the metabolic clearance of a broad range of natriuretic peptides from circulation. The intracellular domain of NPRC is coupled to inhibitory G proteins and is involved in mediating signal transduction. In order to further elucidate the role of NPRC in signal transduction a proteomic approach was taken to identify putative protein binding partners for NPRC in different cell-types. An interrogation of the molecular association between NPRC and its identified protein binding partner(s) …

Faculty Publications 2008, Lsu Health Sciences Center New Orleans

Historical Faculty Publications

This Faculty bibliography contains 629 publications.