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The Methuselah Family Of G Protein Coupled Receptors, Meghna V. Patel

Wayne State University Dissertations

G protein-coupled receptors (GPCRs) are one of the largest class of transmembrane signaling proteins that regulate essential developmental and physiological processes in a cell. GPCR success is illustrated by their abundance across both invertebrate and vertebrate genomes. Phylogenetic analyses show that GPCR families have undergone a lot of gene gain and loss during insect evolution. In Drosophila melanogaster, the fifteen Methuselah/Methuselah-like (Mth/Mthl) genes are in fact an insect specific family of GPCRs. In our study, we conducted a phylogenetic analysis using receptor sequences from five Drosophila species and two related insects, including Tribolium and Anopheles to examine the evolution of …

The Role Of Cad,Flash And Fam129b In Cancer Cell Survial And Apoptosis, Song Chen

Wayne State University Dissertations

Apoptosis is a normal process in the human body. However, apoptosis is desregulated in cancer cells. Most cancer cells gain resistance to apoptosis, leading to uncontrolled proliferation. In this dissertation, we identified three proteins, associated with apoptosis pathway. 1) CAD, a large multifunctional complex that is invariably elevated in tumor cells, 2) FLASH, a large protein with multiple growth related functions and 3) FAM129B. We demonstrate that CAD could interact with FLASH by using yeast two hybrid, co-immunopreciptation and fluorescence microscopy. In addition, functional analysis using siRNA technology further indicated that CAD could co-operate with FLASH and play roles in …

A Role For Reactive Oxygen Species In Photodynamic Therapy, Michael Price

Wayne State University Dissertations

Photodynamic therapy (PDT) is based on the ability of certain photosensitizing agents to selectively localize in neoplastic cells and their vasculature. Subsequent irradiation at a wavelength corresponding to a photosensitizer absorbance band excites the photosensitizer molecules, leading to energy transfer reactions and fluorescence. It was initially concluded that the phototoxic effect occurred when energy from the excited state of the photosensitizer was transferred to dissolved oxygen to form singlet oxygen. This product has a very brief half-life and will cause cellular damage only in the immediate vicinity of its formation. But an excited-state photosensitizer can also interact with oxygen to …

Molecular Mechanisms Of Strain-Stimulated Intestinal Epithelial Cell Differentiation And Migration, Lisi Yuan

Wayne State University Dissertations

The intestinal epithelium is subjected to repetitive deformation during normal gut function by peristalsis and villous motility. In vitro, cyclic strain promotes intestinal epithelial proliferation and induces an absorptive phenotype characterized by increased dipeptidyl dipeptidase (DPPIV) expression. Schlafen 3 is a novel gene recently associated with cellular differentiation. We sought to evaluate whether Schlafen 3 mediates the effects of strain on the differentiation of IEC-6 intestinal epithelial cells in the absence or presence of cyclic strain. Strain increased Schlafen 3 mRNA and protein. In cells transfected with a control non-targeting siRNA, strain increased DPPIV specific activity. However, Schlafen

3 reduction …

Hyperosmotic Stress Enzyme Signaling Modulates Oct4, Nanog, And Rex1 Expression And Induces Prioritized Differentiation Of Murine Embryonic Stem Cells, Jill A. Slater

Wayne State University Dissertations

HYPEROSMOTIC STRESS ENZYME SIGNALING MODULATES OCT4, NANOG,

AND REX1 EXPRESSION AND INDUCES PRIORITIZED DIFFERENTIATION OF

MURINE EMBRYONIC STEM CELLS

by

JILL SLATER

MAY 2013

Advisor: Daniel Rappolee, Ph.D.

Major: Physiology

Degree: Doctor of Philosophy

Transcription factor expression and therefore lineage identity in the periimplantation

embryo and its stem cells may be influenced by extracellular stresses,

potentially affecting pregnancy outcome. Cellular stress forces cells to suppress some

normal activities (such as protein synthesis and cell proliferation) in order to repair

stress-damaged macromolecules and restore homeostasis. Therefore, any new

activities that embryonic cells initiate while concurrently funding the demands of the

stress …

Cellular Plasticity In White Adipose Tissue: In Vivo Identification Of Bipotent Adipocyte Progenitors In Adult White Adipose Tissue, Yun-Hee Lee

Wayne State University Dissertations

Nutritional and pharmacological stimuli can dramatically alter the cellular composition and phenotype of white adipose tissue (WAT). Nonetheless, the identity of progenitors that contribute to this cellular plasticity in vivo remains poorly understood. Utilizing genetic lineage tracing techniques in combination with in situ imunohistochemical analysis, we demonstrate that brown adipocytes (BA) that are induced by beta3-adrenergic receptor activation (ADRB3) in WAT arise from the proliferation and differentiation of cells that express platelet-derived growth factor receptor alpha (PDGFRA), CD34 and Sca1 (PDGFRA+ cells). PDGFRA+ cells have a unique morphology in which extended processes contact multiple cells in the tissue microenvironment. Surprisingly, …

Identifying Sm22 As A Key Player In Arterial Diseases, Jianbin Shen

Wayne State University Dissertations

Background : Expression of vascular smooth muscle cell (VSMC) cytoskeleton markers including SM22 is down-regulated in arterial diseases including atherosclerosis where inflammation and osteochondrogenesis are present. However, the role of this downregulation in arterial pathogenesis is unknown. Hypothesis : Downregulation of SM22 may actively contribute to arterial pathogenesis. Methods : Five Sm22 knockout (Sm22^-/-) mice and their wild type littermates were subjected to carotid artery denudation, an artery injury model. Analyses were conducted on carotid arteries 2 weeks after injury. Primary VSMCs were isolated from mouse aortas and investigated individually at passage 2 to 4. Sm22 knockdown was …

Identification Of Cellular Functions Of Cardiolipin As Physiological Modifiers Of Barth Syndrome, Amit Shridhar Joshi

Wayne State University Dissertations

Cardiolipin (CL) is an anionic phospholipid synthesized in the mitochondrial inner membrane. Perturbation of CL metabolism leads to Barth syndrome (BTHS), a life threatening genetic disorder. I utilized genetic, biochemical and cell biological approaches in yeast to elucidate the cellular functions of CL. Understanding the functions of CL is expected to shed light on the pathology and possible treatments for BTHS.

BTHS is caused by mutations in TAZ1, which encodes a CL remodeling enzyme called tafazzin. BTHS patients exhibit a wide range of clinical presentations, indicating that physiological modifiers influence the BTHS phenotype. A targeted synthetic lethality screen was performed …

Biophysical And Biochemical Factors In The Cellular Microenvironment; Effects On Cell Migration And Invasion, Shalini Menon

Wayne State University Dissertations

Cellular migration is a vital process central to many physiological events including development, immune surveillance and wound healing. However, migration and invasion are not unique to normal physiology, they are also key determinants in the progression of disease states such as cancer. Given the significance of migration it is important that we understand how the process is regulated intracellularly and the various stimuli that can promote it. Even though the role of biochemical factors in mediating migration has been studied extensively, the role of biophysical factors in modulating migration and invasion is less appreciation. The biochemical and biophysical components of …

Hdm2 Small-Molecule Inhibitors For Therapeutic Intervention In B-Cell Lymphoma, Angela Sosin

Wayne State University Dissertations

Lymphomas frequently retain wild-type (wt) p53 function but overexpress HDM2, compromising p53 activity. Therefore, lymphoma is a suitable model for studying therapeutic value of disrupting HDM2-p53 association by small-molecule inhibitors (SMIs). HDM2 SMIs have been developed and are currently under various stages of preclinical and clinical investigation. This study examined various molecular mechanisms associated and biological effects of two different classes of HDM2 SMIs: the spiro-oxindoles (MI-219) and cis-imidazoline (Nutlin-3) in lymphoma cell lines and patient-derived B-lymphoma cells. Surprisingly, results revealed significant quantitative and qualitative differences between these two agents. At the molecular level, effect of Nutlin-3 was generally more …