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Full-Text Articles in Life Sciences

Characterization Of High-Voltage-Activated Calcium Channels In Retinal Bipolar Cells, Qi Lu Jan 2013

Characterization Of High-Voltage-Activated Calcium Channels In Retinal Bipolar Cells, Qi Lu

Wayne State University Dissertations

Retinal bipolar cells, conveying visual information from photoreceptors to ganglion cells, segregate visual information into multiple parallel pathways through their diversified cell types and physiological properties. Voltage-gated Ca2+ channels could be particularly important underlying the diversified physiological properties of different BCs. In this dissertation, I investigated the high-voltage-activated (HVA) calcium current in retinal bipolar cells in mice. In the first part of my dissertation, I characterized multiple bipolar cell-expressing GFP and/or Cre transgenic mouse lines. In the second part of my dissertation, by performing whole-cell patch-clamp recordings, I examined the electrophysiological properties of HVA calcium currents among CBCs ...


Regulation Of Nuclear Localization Of The Sole Sumo-Conjugating Enzyme, Ubc9, Palak Sekhri Jan 2013

Regulation Of Nuclear Localization Of The Sole Sumo-Conjugating Enzyme, Ubc9, Palak Sekhri

Wayne State University Theses

The covalent and reversible conjugation of small ubiquitin-like modifier (SUMO) proteins to hundreds of different cellular proteins is catalyzed by a cascade of enzymes including an E1-activating enzyme (SAE1/SAE2), an E2-conjugating enzyme (Ubc9) and multiple E3 ligases. As the only E2 enzyme for SUMO-conjugation, Ubc9 localizes mainly in the nucleus and plays an essential role in regulation of many cellular processes including cell cycle progression through mitosis, cell migration, genome stability, stress response, transcription, and nuclear transport in eukaryotic cells. It is hypothesized that the nuclear localization of Ubc9 is required for efficient sumoylation inside the nucleus because both ...


The Xenopus Lefty (Xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion, Adrian Amelio Vasquez Jan 2013

The Xenopus Lefty (Xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion, Adrian Amelio Vasquez

Wayne State University Theses

In vertebrates, the TGF #914; superfamily of secreted peptides are stringently regulated since they are responsible for multiple cell processes and behaviors that give rise to the proper patterning of embryonic tissues. Examples of members of the TGF #914; superfamily are Nodal and Lefty. Dysregulation of these proteins can lead to many diseases and developmental syndromes in humans.

Lefty functions by antagonizing Nodal an essential organizer signal that patterns dorsal mesoderm and the embryonic axes. Loss of Lefty expression results in excess Nodal signaling which has been shown to cause several perturbations including metastatic cancer. Although studies have clearly shown ...


Influence Of Mechanical Cues And The Extracellular Matrix On Cell Migration Patterns And The Proliferation Rates Of Cells, Tara Shane Alger Jan 2013

Influence Of Mechanical Cues And The Extracellular Matrix On Cell Migration Patterns And The Proliferation Rates Of Cells, Tara Shane Alger

Wayne State University Theses

The mechanical environment of a cell and its tissue can impact multiple biological processes including development, wound healing, and metastasis. Specific cellular behaviors influenced by the mechanical microenvironment include differentiation, morphology, apoptosis, migration, and proliferation. In this thesis I have focused specifically on the effect of environmental stiffness and applied mechanical forces on cellular migration and proliferation, respectively. Using two different applications, both tailored to evaluate the mechanical forces alone on cellular behavior, I attempted to simulate the mechanical composition of the in vivo tissue microenvironments in vitro using polyacrylamide hydrogels. To test whether cells maintain a mechanical memory for ...


Defining The Mechanism Of Enhanced Cellular Invasion Induced By Mechanical Stimulation, Snehal Sunil Ozarkar Jan 2013

Defining The Mechanism Of Enhanced Cellular Invasion Induced By Mechanical Stimulation, Snehal Sunil Ozarkar

Wayne State University Theses

Metastasis is a multistep process driven by various biochemical and mechanical factors, which eventually leads to formation of secondary tumors. The tumor mass is surrounded by basement membrane (BM) and stroma made of various extracellular matrix (ECM) proteins. During metastasis tumor cells disseminate from the primary tumor, breach the BM, invade the stroma, travel through blood and lymph and colonize tissues distant from the primary tumor. Formation of secondary tumors by metastasis is a leading cause of death in cancer patients. Even though plenty of research has been focused on biochemical factors affecting metastasis, information on role of mechanical factors ...


Studies Of Regulated Exocytosis From Neuroendocrine Cells, Madhurima Das Jan 2013

Studies Of Regulated Exocytosis From Neuroendocrine Cells, Madhurima Das

Wayne State University Theses

In this thesis we study cargo release and fusion pore dilation during calcium triggered exocytosis and the co-localization of calcium sensing proteins essential for exocytosis, in neuroendocrine cells.

Pancreatic beta cells secrete several hormones, the most studied one being insulin. C-peptide is a protein which is co-stored with and secreted from the same vesicles as insulin. It is found in the soluble phase unlike insulin, which is found in the dense core. The pancreatic beta cells also secrete the Chromogranin B (CgB) which is mostly found in the dense cores of secretory vesicles. In chapter 1, we found that CgB ...


Optimization Of Labeling Techniques; Determination Of Best Parameter For Olfactory Mucosal Progenitor Cell Delivery And Study Of Effects Of Methylene Blue And Polyethylene Glycol In An Animal Model Of Spinal Cord Injury, Kiran Kumar Rokkappanavar Jan 2013

Optimization Of Labeling Techniques; Determination Of Best Parameter For Olfactory Mucosal Progenitor Cell Delivery And Study Of Effects Of Methylene Blue And Polyethylene Glycol In An Animal Model Of Spinal Cord Injury, Kiran Kumar Rokkappanavar

Wayne State University Theses

In the United States, the incidence of TSCI is about 40 per million persons per year, with approximately 250,000 living survivors of TSCI in the United States in July 2005. A number of human clinical trials (85) are ongoing using stem cells to evaluate the methods to reduce the injury following TBI. Among the stem cells, olfactory mucosal progenitor cells have several advantages with respect to ease of obtaining, fate of cells, etc. Our study was intended to optimize the labeling technique and to determine the best parameter to deliver the stem cells to the site of injury. We ...


Acidic Pericellular Ph: Effects On Proteolysis And Gene Expression As Determined In 3d Models Of Breast Carcinoma, Jennifer M. Rothberg Jan 2013

Acidic Pericellular Ph: Effects On Proteolysis And Gene Expression As Determined In 3d Models Of Breast Carcinoma, Jennifer M. Rothberg

Wayne State University Dissertations

Among the non-cellular microenvironmental factors that contribute to malignancy of solid tumors is an acidic peritumoral pH. The first objective was to determine if an acidic extracellular pH observed in vivo (i.e., pHe 6.8) affects the activity of proteases, such as cathepsin B, that contribute to degradation of collagen IV by tumor cells when grown in biologically relevant three-dimensional cultures. At pHe 6.8 there were increases in pericellular active cysteine cathepsins and in degradation of DQ-collagen IV, which was partially blocked by a cathepsin B inhibitor. Imaging probes for active cysteine cathepsins localized to tumors in vivo ...


The Transcriptional Regulation Of Flagellin-Induced Innate Protection Of The Cornea: Role Of Irf1 And Atf3, Gi Sang Yoon Jan 2013

The Transcriptional Regulation Of Flagellin-Induced Innate Protection Of The Cornea: Role Of Irf1 And Atf3, Gi Sang Yoon

Wayne State University Dissertations

Pre-exposure of the cornea to TLR5 ligand flagellin induces profound mucosal innate protection against infections by reprogramming gene expression. This study explored the flagellin-induced modifications of transcription factor expression and function, specifically of IRF1 and ATF3 in corneal epithelial cells to elucidate the transcriptional mechanisms underlying the protective function of flagellin on the cornea.

Initially we used Superarray to screen for transcription factors and identified Interferon Regulatory Factor (IRF) 1 and Activating Transcription Factor (ATF) 3 as the most drastically affected genes by flagellin pretreatment in P. aeruginosa challenged human corneal epithelial cells (CEC). However, flagellin pretreatment had opposite effects ...


Desensitization Of Basal Cell Carcinoma To The Anti-Tumoral Effect Of Vitamin D, Rawia Khasawneh Jan 2013

Desensitization Of Basal Cell Carcinoma To The Anti-Tumoral Effect Of Vitamin D, Rawia Khasawneh

Wayne State University Dissertations

The relationship between Vitamin D and NMSC is not very clear. Most of human studies in literature in regards to vitamin D and NMSC are epidemiological which are inconsistent and inconclusive. Mechanistic studies about BCC are few, and mostly are animal models or cell cultures. The main goal for this study is to interpret the impact of vitamin D status on the onset and progression and possibly treatment of basal cell carcinoma. Three tissue samples were collected from BCC patients (Cancer, Proximal, and Distal), and from cancer-free individuals from southeast Michigan. This study design helps identifying alterations in the genetic ...