Biochemistry, Biophysics, and Structural Biology Commons^™

Characterization Of Innate Immunity In The Female Reproductive Tract For The Prevention Of Hiv Acquisition, Colleen Eade

Electronic Theses and Dissertations

Human immunodeficiency virus (HIV) infects 30 million people worldwide. In sub-Saharan Africa, the region most affected by HIV, women comprise 60% of the infected population. Heterosexual transmission is a major mode of viral acquisition, mandating further research of the process and prevention of HIV acquisition via the female reproductive tract (FRT). The FRT is a dynamic environment, protected by host immune mechanisms and commensal microbes. The disruption of either of these elements can increase susceptibility to HIV. Accordingly, one common risk factor for HIV acquisition is the microbial shift condition known as bacterial vaginosis (BV), which is characterized by the …

Molecular Regulators Of Post-Golgi Vldl Transport Vesicle (Pg-Vtv) Biogenesis, Aladdin Riad

Electronic Theses and Dissertations

Amongst its numerous functions, the liver is responsible for the synthesis and secretion of very low-density lipoprotein (VLDL). VLDL particles play the important role of facilitating the transport of lipids within the aqueous environment of the plasma; yet high plasma concentrations of these particles result in the pathogenesis of atherosclerosis, while low VLDL secretion from the liver results in hepatic steatosis. VLDL synthesis in the hepatocyte is completed in the Golgi apparatus, which serves as the final site of VLDL maturation prior to its secretion to the bloodstream. The mechanism by which VLDL’s targeted transport to the plasma membrane is …

Identification Of Proteins Regulating Vldl Sorting Into The Vldl Transport Vesicle (Vtv) And Involved In The Biogenesis Of The Vtv, Samata Tiwari

Electronic Theses and Dissertations

Increased secretion of very low-density lipoprotein (VLDL), a triglyceride-rich lipoprotein, by the liver causes hypertriglyceridemia, which is a major risk factor for the development of atherosclerosis. The rate of VLDL-secretion from the liver is determined by its controlled transport from the endoplasmic reticulum (ER) to the Golgi. The ER-to-Golgi transport of newly synthesized VLDL is a complex multi-step process and is mediated by the VLDL transport vesicle (VTV). Once a nascent VLDL particle is synthesized in the lumen of the ER, it triggers the process of VTV-biogenesis and this process requires coat complex II (COPII) proteins that mediate the formation …

Role Of Host Immune Response And Bacterial Autolysin Atl In Human Nasal Colonization By Staphylococcus Aureus, Vanathy Paramanandam

Electronic Theses and Dissertations

Staphylococcus aureus (SA) is a major human pathogen that colonizes the anterior nares in 30% of the human population. Though nasal carriage of SA is a known risk factor for the subsequent spread of SA infections, the dynamics of SA nasal colonization is poorly understood. Our research focuses on understanding the host and bacterial factors that might contribute to the human nasal colonization by SA. In an attempt to elucidate the host response to SA, we performed an autologous human in vivo nasal colonization study, which showed decreased survival rates of SA in hosts who elicited a robust immune response. …

Determination Of Dimer Dissociation Constant Of Neural-Cadherin By Fluorescence Resonance Energy Transfer, Xiaoyun Z. Howard

Electronic Theses and Dissertations

No abstract provided.

Is Breakdown Of Fatty Acid Peroxides Involved In The Induction Of Apolipoprotein A1?, Rajat Gupta

Electronic Theses and Dissertations

Over the past few years the number of deaths caused due to cardiovascular diseases has been increasing and is of major concern. In the United States, 75% of cardiovascular-related deaths have been attributed to atherosclerosis. Western diets containing large quantities of peroxidized lipids are considered atherogenic. Heated oil in the form of fried food brings high levels of peroxidized fat and its decomposition products in the diet. Peroxidized lipids are known to increase the susceptibility of serum lipoproteins to undergo oxidation, thereby contributing to the progression of atherosclerosis. The intestinal cells are responsible for the absorption of dietary fatty acid …

Identification Of Epithelial Stromal Interaction 1 And Epidermal Growth Factor Receptor As Novel Kruppel-Like Factor 8 Targets In Promoting Breast Cancer Progression, Tianshu Li

Electronic Theses and Dissertations

Breast cancer is the major cause of cancer death among women worldwide. Understanding the mechanisms underlying breast cancer progression remains urgent for developing effective treatment strategies to eliminate breast cancer mortality. Our recent studies have demonstrated that Krüppel-like transcriptional factor 8 (KLF8) plays a critical role for breast cancer progression. Other studies have shown that Epithelial stromal interaction 1 (EPSTI1), a recently identified stromal fibroblast-induced gene in non-invasive breast cancer cells and epidermal growth factor receptor (EGFR) are highly overexpressed in aggressively invasive breast carcinomas including triple negative breast cancers. In this thesis project, we demonstrate high co-overexpression of KLF8 …

The Contribution Of Visceral Fat To Positive Insulin Signaling In Ames Dwarf Mice, Vinal Menon

Electronic Theses and Dissertations

Ames dwarf (df/df) mice are homozygous for a spontaneous mutation in the prop1 gene due to which there is no development of anterior pituitary cells – somatotrophs, lactotrophs and thyrotrophs, leading to a deficiency of growth hormone (GH), prolactin (PRL) and thyrotropin (TSH). They tend to become obese as they age, but still live longer and healthier lives compared to their wild-type littermates, being very insulin sensitive, showing no signs of diabetes and cancer. These mutant mice also have high circulating levels of anti-inflammatory and antidiabetic adiponectin. Plasma levels of this adipokine usually decrease with an increase in accumulation of …

Cerium Oxide Nanoparticles Sensitize Pancreatic Cancer Cells To Radiation By Promoting Acidic Ph, Ros, And Jnk Dependent Apoptosis, Melissa Wason

Electronic Theses and Dissertations

Side effects of radiation therapy (RT) remain the most challenging issue for pancreatic cancer treatment. In this report we determined whether and how cerium oxide nanoparticles (CONPs) sensitize pancreatic cancer cells to RT. CONP pretreatment enhanced radiation-induced reactive oxygen species (ROS) production preferentially in acidic cell-free solutions as well as acidic human pancreatic cancer cells. In acidic environments, CONPs favor the scavenging of superoxide radical over the hydroxyl peroxide resulting in accumulation of the latter whereas in neutral pH CONPs scavenge both. CONP treatment prior to RT markedly potentiated the cancer cell apoptosis both in culture and in tumors and …

The Role Of Mitochondrial Omi/Htra2 Protease In Protein Quality Control And Mitophagy, Camilla Ambivero

Electronic Theses and Dissertations

Omi/HtrA2 is a mitochondrial serine protease with a dual and opposite function depending on its subcellular localization. Most of the previous studies focused on Omi/HtrA2’s pro-apoptotic function when the protein is released to the cytoplasm. It is becoming apparent that the main function of Omi/HtrA2 is within the mitochondria, where it has a pro-survival role. However, its mechanism is still poorly understood. To this end, we used the yeast two-hybrid system to dissect the Omi/HtrA2 pathway by identifying novel interactors and substrates. Our studies revealed a novel function of Omi/HtrA2 in the regulation of a deubiquitinating (DUB) complex. In addition …

The Cytopathic Activity Of Cholera Toxin Requires A Threshold Quantity Of Cytosolic Toxin., Carly Bader

Electronic Theses and Dissertations

Cholera toxin (CT), secreted from Vibrio cholerae, causes a massive fluid and electrolyte efflux in the small intestine that results in life-threatening diarrhea and dehydration which impacts 3-5 million people per year. CT is secreted into the intestinal lumen but acts within the cytosol of intestinal epithelial cells. CT is an AB5 toxin that has a catalytic A1 subunit and a cell binding B subunit. CT moves from the cell surface to the endoplasmic reticulum (ER) by retrograde transport. Much of the toxin is transported to the lysosomes for degradation, but a secondary pool of toxin is diverted to the …

Characterization Of Motility Alterations Caused By The Impairment Of Dynein/Dynactin Motor Protein Complex, Swaran Nandini

Electronic Theses and Dissertations

Transport of intracellular cargo is an important and dynamic process required for cell maintenance and survival. Dynein is the motor protein that carries organelles and vesicles from the cell periphery to the cell center along the microtubule network. Dynactin is a protein that activates dynein for this transport process. Together, dynein and dynactin forms a motor protein complex that is essential for transport processes in all the vertebrate cells. Using fluorescent microscope based live cell imaging techniques and kymograph analyses, I studied dynein/dynactin disruptions on the intracellular transport in two different cell systems. In one set of experiments, effects of …

Bone Morphogenetic Protein-7 (Bmp-7) Polarizes Monocytes Into M2 Macrophages, Crystal Rocher

Electronic Theses and Dissertations

Atherosclerosis is an inflammatory disease in which an accumulation of fatty acids and cholesterol occurs to form a plaque in small and large arteries. Monocyte polarization to classic M1 macrophages or alternative M2 macrophages is an important area of research that can determine the severity of disease progression. BMP-7 is a key growth factor responsible for directing differentiation of mesenchymal stem cells into brown fat cells, suggesting a role of BMP-7 in cellular plasticity; however, its role in monocyte polarization is yet to be revealed. In the current study, we hypothesize that monocyte treatment with BMP-7 will significantly result in …

Delineating Key Genetic Components On Linear Plasmid 36 That Contribute To Its Essential Role In Borrelia Burgdorferi Mammalian Infectivity., Tisha Choudhury

Electronic Theses and Dissertations

The spirochete Borrelia burgdorferi is the etiologic agent of Lyme disease. This pathogen has a complex enzootic life cycle that involves passage between the tick vector (Ixodes scapularis) and various vertebrate hosts with humans being inadvertent hosts. There is a pressing need to study the genetic aspects of the B. burgdorferi infectious cycle and particularly spirochete genes involved in mammalian infectivity so as to develop novel therapeutic and diagnostic strategies to combat Lyme disease. The B. burgdorferi genome is fragmented and comprised of a single 900 kb linear chromosome and multiple linear and circular plasmids. It has been observed that …

Mixed Valence Copper(Cu)/Silica Nanocomposite: Synthesis, Characterization And Systematic Antimicrobial Studies, Mikaeel Young

Electronic Theses and Dissertations

Copper (Cu) compounds are widely used as effective agricultural bactericides. Continuous use of these materials has led to Cu accumulation in soil over time. The United States Environmental Protection Agency (US EPA) is concerned about potential Cu contamination in the environment. Improving biocidal efficacy of Cu is an attractive alternative, allowing reduction of Cu amount per application. In this research, we focused on making watersoluble mixed-valence Copper/Silica composite nanogel (CuSiNG) material. The objective is to improve the efficacy of Cu by manipulating Cu valence states. It has been shown in the literature that Cu (0) and Cu (I) states are …

Immuno-Pcr Detection Of Lyme Borreliosis, Micah Halpern

Electronic Theses and Dissertations

Lyme borreliosis, more commonly referred to as Lyme disease, is the fastest growing zoonotic disease in North America with approximately 30,000 confirmed cases and 300,000 estimated infections per year. In nature, the causative agent of Lyme disease, the bacterium Borrelia burgdorferi, cycles between Ixodes sp. ticks and small mammals. Humans become infected with Lyme disease after being bitten by an infected tick. The primary indicator of a Borrelia burgdorferi infection is a bull’s eye rash typically followed by flu-like symptoms with treatment consisting of a 2-4 week course of antibiotics. If not treated, later stages of the disease can result …

Dubious Role Of Mycobacterium Paratuberculosis In Pathogenesis Of Type I Diabetes, Saisathya Thanigachalam

Electronic Theses and Dissertations

Background: Type 1 Diabetes mellitus (TIDM) is a chronic disorder in which the insulin producing beta cells are selectively self-destroyed. Although the etiology of the disease has not been determined, genetic dispositions such as SLC11A1 polymorphism in suffering patients have been reported. The role of pathogenic microorganisms such as Mycobacterium avium subspecies paratuberculosis (MAP) in TIDM has also been recently debated. MAP is already known to cause paratuberculosis in cattle and now it is a strong suspect of causing autoimmune diseases in humans such as Crohn’s disease, multiple sclerosis, autoimmune Thyroiditis, rheumatoid arthritis and autoimmune diabetes. We hypothesis that molecular …

Transplantation Of Pluripotent Stem Cells Confers Cardiac Protection In Dox-Induced Heart Failure Through Notch-1 Pathway, Hilda Merino-Chavez

Electronic Theses and Dissertations

Doxorubicin (DOX) is the antineoplastic drug of preference used to treat a wide variety of malignancies, with high survival rates among treated patients. However, the benefits of this drug have become less appealing due to the side effects that occur such as DOX-induced cardiomyopathy (DIC) and an increased risk of myocardial infarction (MI). Therefore, there is an urgent need to explore the therapeutic options to treat DIC. In this context, adult stem cells have been used as a source to reduce cardiomyocyte apoptosis in DIC; however, the effects of transplanted embryonic stem (ES) cells and induced pluripotent stem (iPS) cells …

Limk1 Promotes Mt1-Mmp Expression And Localization To The Plasma Membrane, Richard Ottman

Electronic Theses and Dissertations

LIM Kinase 1 (LIMK1), a serine/threonine kinase, modulates actin polymerization and microtubule assembly. The function of LIMK1 is regulated by kinases that are activated by Rho and Rac GTPases. LIMK1 is overexpressed in various cancerous cell types and tissues and its overexpression promotes increased invasion and metastasis of breast and prostate cancer cells. Membrane-Type Matrix Metalloproteinase 1 (MT1-MMP) is a member of the zinc-binding collagenase family, which is involved in extracellular matrix breakdown and activation of secreted MMP-2. The balance between activation and inhibition of MT1- MMP and MMP-2 helps maintaining normal extracellular matrix turnover. However, it has been shown …

Estradiol Modulation Of Calcium Dynamics In Pituitary Mmq Lactotroph Cells, Monika Pauckova

Electronic Theses and Dissertations

Pituitary lactotrophs are excitable cells that exhibit spontaneous, calcium influx triggering prolactin (PRL) secretion to stimulate lactation. Lactotrophs express estrogen receptors (ER) and are a well established estrogen-responsive cell system. 17B-estradiol (E2) is known to directly affect lactotrophs by increasing PRL transcription and biosynthesis, intracellular Ca2+ concentration ([Ca2+]i) and PRL secretion. This study demonstrates that the MMQ clonal cell line, isolated from the 7315a rat pituitary tumor, is a model lactotroph cell line that is E2-responsive. Spontaneous and evoked Ca2+ transients were especially sensitive to L-type channel block, but not affected by block of omega-conotoxin-GVIA-sensitive CaV channels or TTX-sensitive voltage-gated …

Structural Polymorphism In Tau Filaments: An Implication For Neurodegenerative Diseases, Ayisha Siddiqua

Electronic Theses and Dissertations

Tau filaments are the pathological hallmark of >20 neurodegenerative diseases including Alzheimer's disease, Pick's disease, and progressive supranuclear palsy. In the adult human brain, six isoforms of tau are expressed that differ by presence or absence of the second of the four semiconserved repeats. As a consequence, half of the tau isoforms have three repeats (3R tau), whereas the other half has four repeats (4R tau).

Site-directed spin labeling of recombinant tau in conjunction with electron paramagnetic resonance spectroscopy was used to obtain structural insights into tau filaments. The studies showed that the filaments of 4R tau and 3R tau …

A Hydrodynamic Method For Measuring Aqueous Nanoparticle Surface Interactions, Kellen John Sorauf

Electronic Theses and Dissertations

The objectives of this research dissertation were to develop and present novel analytical methods for the quantification of surface binding interactions between aqueous nanoparticles and water-soluble organic solutes. Quantification of nanoparticle surface interactions are presented in this work as association constants where the solutes have interacted with the surface of the nanoparticles. By understanding these nanoparticle-solute interactions, in part through association constants, the scientific community will better understand how organic drugs and nanomaterials interact in the environment, as well as to understand their eventual environmental fate. The biological community, pharmaceutical, and consumer product industries also have vested interests in nanoparticle-drug …

A Novel Link Between Akt1 And Twist1 In Ovarian Tumor Cell Motility And Invasiveness, Nirav Shah

Electronic Theses and Dissertations

Ovarian cancer results in more deaths per year than any other cancer of the female reproductive system. The low survival rate is partly due to the lack of early detection and the susceptibility to relapse. The AKT serine threonine kinase plays a pivotal role in hallmark cellular processes for the progression of ovarian cancer, including tumor cell growth and migration. Therapeutic targeting of pan-AKT has been problematic, in part due to feedback mechanisms and crosstalk with other pathways. The hypothesis for this study is that AKT 1, -2 and -3 isoforms may have different roles and regulate cell processes in …

Fret Studies Of Dna Binding By Lambda Cro Variants, Lei Wang

Electronic Theses and Dissertations

Proteins bind to DNA to form switches and circuits that control the flow of genetic information from DNA sequence to the physical components of cells and organisms. The dynamic performance of genetic switches depends on the coupling of the comprocesses of transcription and translation to protein-specific folding, assembly and binding reactions. For many model circuits protein dimerization and DNA binding are fast relative to the time scale of transcription and translation and thus amenable to modeling by statistical thermodynamics. In these cases, the distribution of proteins between monomers and dimers and between nonspecific and specific DNA complexes can be simply …

Amelioration Of Amyloid Burden In Advanced Human And Mouse Alzheimer's Disease Brains By Oral Delivery Of Myelin Basic Protein Bioencapsulated In Plant Cells, Neha Kohli

Electronic Theses and Dissertations

One of the pathological hallmarks of Alzheimer's disease (AD) is the amyloid plaque deposition in aging brains by aggregation of amyloid-β (Aβ) peptides. In this study, the effect of chloroplast derived myelin basic protein (MBP) fused with cholera toxin subunit B (CTB) was investigated in advanced diseased stage of human and mouse AD brains. The CTB-fusion protein in chloroplasts facilitates transmucosal delivery in the gut by the natural binding ability of CTB pentameric form with GM1 receptors on the intestinal epithelium. Further, bioencapsulation of the MBP within plant cells confers protection from enzymes and acids in the digestive system. Here, …

Identification Of Novel Antimalarial Scaffolds From Marine Natural Products, Bracken Roberts

Electronic Theses and Dissertations

Malaria, the disease caused by Plasmodium sp., claims the lives of over 1 million people every year, with Plasmodium falciparum causing the highest morbidity. Rapidly acquiring drug resistance is threatening to exhaust our antimalarial drug arsenal and already requires the utilization of combination drug therapy in most cases. The global need for novel antimalarial chemical scaffolds has never been greater. Screening of natural product libraries is known to have higher hit rates than synthetic chemical libraries. This elevated hit rate is somewhat attributed to the greater biodiversity available in natural products. Marine life is the most biodiverse system on the …

Light-Activated Binary Nucleotide Reagent For Inactivation Of Dna Polymerase, Evan M. Cornett

Electronic Theses and Dissertations

This work explores a binary reagent approach to increase the specificity of covalent inhibitors. In this approach, two ligand analogs equipped with inert pre-reactive groups specifically bind a target biopolymer. The binding event brings the pre-reactive groups in proximity with each other. The two groups react, generating active chemical intermediates that covalently modify and inactivate the target. In the present study we compare the new approach with the traditional single-component reagent strategy using DNA polymerase from bacteriophage T4 as a model target biopolymer. We report the design and synthesis of two analogs of deoxythymidine triphosphate, a natural DNA polymerase substrate. …

Molecular Mechanisms Involved In Inflammatory Angiogenesis Induced By Monocyte Chemotactic Protein Induced Protein-1 (Mcpip1), Arpita Roy

Electronic Theses and Dissertations

Major diseases such as cardiovascular diseases, diabetes, obesity and tumor growth are known to involve inflammatory angiogenesis. MCP-induced protein 1 (MCPIP1) encoded by ZC3H12A gene, was reported to promote angiogenesis and is addressed in my dissertation as MCPIP. The mechanism/s involved in the angiogenic differentiation induced by MCPIP was however unknown. The aim of this study was to bridge this gap in our knowledge and delineate the molecular mechanisms and sequential processes involved in angiogenesis mediated via MCPIP. To determine if angiogenesis induced by inflammatory cytokines, TNF-, IL-1 and IL-8 is mediated via induction of MCPIP, knockdown of MCPIP by …

The Dynamic Functions Of Bax Are Dependent On Key Structural And Regulatory Features, Rebecca Boohaker

Electronic Theses and Dissertations

Bax is an essential mediator of cell fate. Since its discovery in 1985 as a protein that interacts with the anti-apoptotic protein, Bcl-2, key elements related to its function, structure and regulation remains to be determined. To this end, mitochondrial metabolism was examined in non-apoptotic Bax-deficient HCT-116 cells as well as primary hepatocytes from Bax-deficient mice. Although mitochondrial density and mitochondrial DNA content was the same in Bax-containing and Bax -deficient cells, MitoTracker staining patterns differed, suggesting the existence of Bax -dependent functional differences in mitochondrial physiology. Oxygen consumption and cellular ATP levels were reduced in Bax -deficient cells, while …

Signals Delivered By Interleukin-7 Regulate The Activities Of Bim And Jund In T Lymphocytes, Shannon Moore Ruppert

Electronic Theses and Dissertations

Interleukin-7 (IL-7) is an essential cytokine for lymphocyte growth that has the potential for promoting proliferation and survival. While the survival and proliferative functions of IL-7 are well established, the identities of IL-7 signaling components in pathways other than JAK/STAT, that accomplish these tasks remain poorly defined. To this end, we used IL-7 dependent T-cells to examine those components necessary for cell growth and survival. Our studies revealed two novel signal transducers of the IL-7 growth signal: BimL and JunD. IL-7 promoted the activity of JNK (Jun N-terminal Kinase), and that JNK, in turn, drove the expression of JunD, a …