Life Sciences Commons^™

Does Vdac2 Have A Bh3 Domain?, Lillian Ferkany

Honors Theses

Mitochondrial outer membrane permeabilization (MOMP) by Bax oligomerization triggers apoptosis. BCl-2 family proteins, classified as BH3 only proteins, pro-survival proteins, or pro-apoptotic proteins, control apoptosis partly through their agonist or antagonistic effects on Bax, which are mediated by their conserved BH3 domains. All BH3 domains form an alpha helix containing 5-7 conserved hydrophobic residues, designated H0-H5, and one conserved aspartic acid that drive interaction with Bax and other ‘multi-domain’ BCl-2 members. BH3 agonists induce Bax oligomerization, while BH3 antagonists sequester Bax to prevent MOMP. We discovered that voltage dependent anion channels (VDACs) in the MOM contain a putative BH3-like domain …

Till Death Do Us Part: The Marriage Of Autophagy And Apoptosis., Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Autophagy is a widely conserved catabolic process that is necessary for maintaining cellular homeostasis under normal physiological conditions and driving the cell to switch back to this status quo under times of starvation, hypoxia, and oxidative stress. The potential similarities and differences between basal autophagy and stimulus-induced autophagy are still largely unknown. Both act by clearing aberrant or unnecessary cytoplasmic material, such as misfolded proteins, supernumerary and defective organelles. The relationship between reactive oxygen species (ROS) and autophagy is complex. Cellular ROS is predominantly derived from mitochondria. Autophagy is triggered by this event, and by clearing the defective organelles effectively, …

Role Of Rgs2 In Cellular Stress, Chang-Hui Wang

Electronic Thesis and Dissertation Repository

Stresses from the external environment can disrupt cellular processes and result in damaging effects, such as the misfolding of proteins, which have been linked to several diseases. Regulator of G protein signalling 2 (RGS2) is upregulated by several forms of stress and can inhibit protein synthesis, an established response to stress typically achieved via the phosphorylation of the initiation factor, eIF2, to conserve energy and resources. Under reduced translation, some factors are selectively expressed via alternative translation mechanisms and these factors consequently may promote apoptosis. The molecular mechanisms mediating such opposing responses to stress are not well understood. Here, we …

Mechanisms Of Neural Precursor Cell Apoptosis By Microglia-Derived Cytokines, Jennifer Guadagno

Electronic Thesis and Dissertation Repository

The persistence of neural precursor cells (NPCs) in distinct niches of the adult brain and spinal cord provides an important opportunity for regeneration in the affected nervous system. In the adult brain, neural precursor cells (NPCs) generate new neurons that can be integrated into the CNS circuitry to replace damaged or lost neurons, and contribute to learning and memory processes. Deregulated neurogenesis has been observed under both acute and chronic neurological conditions including stroke, Alzheimer’s disease, and Parkinson’s disease. The extent to which neurogenesis contributes to brain repair is severely limited by the neuroinflammatory processes associated with these neurodegenerative conditions. …

The Physiological Stress Response Caused By Hypoxia And Reperfusion Injury In Striped Bass (Morone Saxatilis) And Nile Tilapia (Oreochromis Niloticus), Amanda C. Reynolds

Electronic Theses and Dissertations

Approximately five million people in the United States are affected by cardiovascular related diseases yearly contributing to 300,000 annual deaths, making CVD the leading cause of mortality worldwide. It has been suggested that apoptosis (programmed cell death) contributes to the pathogenesis of cardiovascular diseases. When blood flow is reduced or cut off from the heart, usually by a thrombus, this results in oxygen deprivation (hypoxia) to the cardiomyocytes (heart cells). In response to this hypoxic stress, cardiomyocytes will undergo apoptosis. Since many species of fish can survive levels of hypoxia that would be fatal to mammals, fish are an ideal …

Ilk Modulates Stress-Induced Apoptosis In Epidermal Keratinocytes, Michelle Im

Electronic Thesis and Dissertation Repository

Integrin-linked kinase (ILK) is a ubiquitous scaffold protein that mediates cellular responses to integrin stimulation by extracellular matrix proteins. Mice with inactivation of the Ilk gene in squamous epithelia display defects in skin regeneration after injury, failure to thrive, and perinatal death. ILK-deficient epidermis exhibits reduced adhesion to the basement membrane and impaired hair follicle morphogenesis. In culture, ILK-deficient keratinocytes fail to attach and spread efficiently, and demonstrate decreased survival. We now show that ILK-deficient keratinocytes exhibit lower proliferative capacity and increased apoptosis in the absence or presence of growth factors. This reduced viability appears to be independent of the …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

A C-Terminus Mitochondrial-Localization Region And Bh3 Domain Of Puma Are Required For Apoptotic Function, Liz A. Merwin

Electronic Thesis and Dissertation Repository

Apoptosis is known to contribute to the loss of neurological function in brain injury and several neurodegenerative diseases. The Bcl-2 family of proteins consist of pro-apoptotic and anti-apoptotic members that interact physically and functionally to regulate apoptosis in a cell type and stimulus specific manner. We have previously demonstrated that the Bcl-2 family member Puma plays a key role in triggering neuronal apoptosis under diverse stress conditions. However, the mechanism by which Puma mediates apoptosis remains unclear. Here we found that Puma contains two domains required for its apoptotic function: the BH3 domain and a region in the c-terminus that …

Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards

Senior Honors Theses

A cell may use one of three main apoptotic pathways leading to programmed cell death: the extrinsic pathway, the perforin/granzyme pathway and the intrinsic pathway. The most pertinent to this discussion is the intrinsic pathway, which utilizes the mitochondria as an essential intermediary. Mitochondria’s primary function in relation to this pathway is the subsequent release of pro-apoptotic factors including cytochrome c, which activate a caspase cascade leading to the death of the cell. Cytochrome c is released partly due to an increase in cytosolic calcium levels. Two methods of the release of cytochrome c have been proposed. The first is …

The Time-Course Of The Effects Of Growth Hormone During Zebrafish (Danio Rerio) Auditory Hair Cell Regeneration, Yajie Wang

Masters Theses & Specialist Projects

Growth hormone (GH) was upregulated in the zebrafish inner ear following sound exposure in a previous study. To identify the specific role of GH in hair cell regeneration and the possible cellular mechanisms of this regeneration, groups of zebrafish were divided into baseline (no sound exposure, no injection), buffer-injected and GH-injected groups. Buffer- and GH-injected fish were exposed to a 150 Hz tone at a source level of 179 dB re 1 μPa root mean squared (RMS) for 36 h. Phalloidin-staining was used to assess the effects of GH on hair cell bundle density; BrdU-labeling was used to assess the …

Dose-Dependent Thresholds Of 10-Ns Electric Pulse Induced Plasma Membrane Disruption And Cytotoxicity In Multiple Cell Lines, Bennett L. Ibey, Caleb C. Roth, Andrei G. Pakhomov, Joshua A. Bernhard, Gerald J. Wilmink, Olga N. Pakhomova

Bioelectrics Publications

In this study, we determined the LD50 (50% lethal dose) for cell death, and the ED50 (50% of cell population staining positive) for propidium (Pr) iodide uptake, and phosphatidylserine (PS) externalization for several commonly studied cell lines (HeLa, Jurkat, U937, CHO-K1, and GH3) exposed to 10-ns electric pulses (EP). We found that the LD50 varied substantially across the cell lines studied, increasing from 51 J/g for Jurkat to 1861 J/g for HeLa. PS externalized at doses equal or lower than that required for death in all cell lines ranging from 51 J/g in Jurkat, to 199 J/g in CHO-K1. Pr …

The Role Of Fas And Fas Ligand In Apoptosis During Regression Of The Corpus Luteum, Sharon Roughton

Theses : Honours

Apoptosis, a form of physiological cell death, has been found to occur during regression of the corpus luteum (Juengel etal, 1993; Dharmarajan etal, 1994). The pathways involved in this process, however, have yet to be specified. One possible mediator of corpus luteum regression is the Fas (or AP0-1 or CD95) receptor, a transmembrane protein which induces apoptosis in the cell when ligated. In order to further confirm this hypolhesis, the present study establishes and quantitates the presence and regulation of Fas receptor and Fas ligand (Fasl) in the rat corpus luteum during pregnancy and post-partum. The animals used were sexually …