Medicine and Health Sciences Commons^™

The Role Of Cytoprotective And Non-Protective Autophagy In Radiation Sensitivity In Breast Tumor Cells, Jade Le

Theses and Dissertations

In general, ionizing radiation promotes cytoprotective autophagy in a majority of breast tumor cells. Previous studies from our laboratory indicated that radiation (5x2 Gy) induces cytoprotective autophagy in MCF-7 cells. In the current work, inhibition of autophagy by silencing of Beclin-1 in MCF-7 cells resulted in an increase in sensitivity to radiation based both on cell number and clonogenic survival; however, there was no increase in apoptosis and the basis for this sensitization is currently under investigation. Unexpectedly, enhancement of autophagy by silencing of Bcl-2 also led to an increase in sensitivity to radiation, possibly through the conversion of cytoprotective …

Cytoprotective Versus Non-Protective Autophagy Induced By Radiation In Head And Neck Cancer Cells, Duaa Bakhshwin

Theses and Dissertations

The primary treatment options for head and neck cancer are radiation therapy or surgery, or both combined; chemotherapy is often used as an additional, or adjuvant, treatment. Patients treated with radiotherapy are exposed to a high cumulative dose of radiation over a period of time and there is a 17-33% chance of recurrence. High cumulative doses of radiation, a long time course of treatment, side effects and the possibility of recurrence provide the rationale for developing approaches for radiation sensitization, which could be helpful to patients in decreasing the dose, duration of radiation, side effects, or the chance of recurrence. …

Irradiation Of Hs578t Breast Tumor Cells Induces Non-Cytoprotective Autophagy, Aisha Alhaddad

Theses and Dissertations

Cancer is the second most common cause of death in the US. The most frequently observed cancer type in women is breast cancer. A special type of breast cancer is triple negative (TNBC) cancer that is characterized by lacking three receptors: estrogen, progesterone and human epithelial growth factor (HER 2). The HS578t breast cell line is a model of TNBC that also has a mutation of the p53 protein. Ionizing radiation is used widely in the clinic to debulk tumors before surgery as well as post-surgery to eliminate residual tumor cells outside the surgical field. Previous studies from our laboratory …

Glial Cell Modulators And Associated Anti-Inflammatory Activity: Implications In Reducing Methamphetamine Abuse-Related Behaviors In Rodents, Sarah Snider

Theses and Dissertations

Methamphetamine is a psychomotor stimulant that produces hyperactivity and euphoria and can lead to drug-seeking and abuse. An estimate from 2005 put the cost of methamphetamine abuse to society at an estimated 23.4 billion dollars. One of methamphetamine's effects is activation of glial cells and associated neuroinflammatory activity in the periphery and CNS. Glia are responsible for maintaining calcium homeostasis, neuroplasticity, immune activity, and cell signaling. Activation of glia and neuroinflammation are becoming recognized as links in drug abuse-related behavior. The goal of the present work was to assess the ability of ibudilast, AV1013, and minocycline, three glial cell modulating …

Characterization Of The Discriminative Stimulus Effects Of Nitrous Oxide, Kellianne J. Richardson

Theses and Dissertations

Nitrous oxide (N2O) is a widely used anesthetic adjunct in dentistry and medicine that is also commonly abused. N2O alters the function of several receptors in vitro and ex vivo, however, the receptors systems underlying its abuse-related intoxicating effects are poorly understood. The goals of this dissertation were to (1) establish N2O as a discriminative stimulus, (2) characterize the temporal properties of the discriminative stimulus, (3) determine the degree of similarity between N2O and other inhalants and (4) explore the neurochemical effects responsible for the stimulus properties of N2O. Twenty-four mice were trained to discriminate 10 minutes exposure to 60% …

Redox Triggering Of Podocyte Nlrp3 Inflammasomes And Glomerular Injury In Hyperhomocysteinemia, Justine M. Abais

Theses and Dissertations

Hyperhomocysteinemia (hHcys), an important pathogenic factor contributing to the progression of end-stage renal disease (ESRD), has been shown to activate NOD-like receptor protein 3 (NLRP3) inflammasomes and cause podocyte dysfunction and glomerular sclerosis. hHcys induces aggregation of the three inflammasome components – NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1 – and its activation is indicated by increased caspase-1 activity and secretion of interleukin-1β (IL-1β). The aims of the present study sought to elucidate the role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mediated redox signaling in hHcys-induced NLRP3 inflammasome activation, to dissect the contribution of common endogenous reactive oxygen species (ROS) …

The Role Of P2x Receptors In Hiv And Opiate-Related Neurotoxicity, Mary Sorrell

Theses and Dissertations

Emerging evidence suggests that opioid drugs can exacerbate neuroAIDS. Microglia are the principal neuroimmune effectors thought to be responsible for neuron damage in HIV-infected individuals, and evidence suggests that drugs acting via opioid receptors in microglia aggravate the neuropathophysiological effects of HIV. The P2X family of ATP activated ligand-gated ion channels regulates key aspects of microglial function. In addition, opioid-dependent microglial activation has been reported to be mediated through P2X4 signaling, prompting us to investigate P2X receptors contribution to the neurotoxic effects of HIV and morphine. In vitro experiments showed treatment with TNP-ATP prevented the neurotoxic effects of morphine and/or …

Behavioral Assessment And Hplc/Ms/Ms Identification Of The Synthetic Cannabinoid, Cp47,497, In Mice, Kimberly L. Samano

Theses and Dissertations

CP47,497 and other synthetic cannabinoid compounds were incipiently synthesized as research tools to investigate the mechanisms by which marijuana affects the brain and to aid in the development of therapeutic agents. Recently, these cannabinoid compounds have resurfaced in the designer drug market, marketed as “herbal incense products” (HIPs). Their popular use has resulted in an alarming rate of reported adverse effects and toxicities. Current legislation classified CP47,497 and several other synthetic cannabinoids compounds as Schedule I agents, but abuse of these compounds persists with serious consequences to public health and safety. In vivo studies examining the behavioral consequences of abused …

A Direct And Indirect Mechanism For Ccr5 In Morphine And Hiv-1 Mediated Neurodegeneration, Elizabeth Podhaizer

Theses and Dissertations

A DIRECT AND INDIRECT MECHANISM FOR CCR5 IN OPIOID AND HIV-1 MEDIATED NEURODEGENERATION By Elizabeth M. Podhaizer, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2014 Major Director: Kurt F. Hauser, Ph.D., Professor of Pharmacology & Toxicology Human immunodeficiency virus (HIV)-1 infection currently affects over 34 million people worldwide, and despite the use of cART, the prevalence of HIV-1 associated neurocognitive impairments (HAND) has not declined. Additionally, other co-morbid factors such as the abuse of injection drugs (i.e. heroin, morphine) increase both the frequency …

Targeting The Endocannabinoid Metabolic Enzymes To Reduce Inflammatory Pain, Sudeshna Ghosh

Theses and Dissertations

Pain is a debilitating condition that presents a problem of clinical relevance. Common analgesics include opioids and non-steroidal anti-inflammatory drugs (NSIADs). Despite different degrees of effectiveness, a major drawback of these analgesic classes is their side effects. For example, side effects associated with opioids include pruritus, respiratory depression, hyperalgesia, constipation, dependence. In addition, chronic use of NSAIDs can cause gastric ulcers. Delta-9 tetrahydrocannabinol (THC), the primary psychoactive constituent of marijuana, produces antinociception in various preclinical models of pain. Similarly, many synthetic cannabinoid receptor agonists produce antinociception in preclinical models of pain. However, their psychomimetic effects dampen interest for their therapeutic …

Combined Antiproliferative Effects Of The Aminoalkylindole Win55,212-2 And Radiation In Breast Cancer Cells, Sean Emery

Theses and Dissertations

The potential antitumor activity of mixed CB1/CB2 cannabinoid receptor agonists, such as the aminoalkylindole WIN55,212-2 (WIN2), has been extensively studied, but little information is available as to their potential interaction with conventional cancer therapies, such as ionizing radiation (IR). In the present work, we investigated the effects of WIN2 on the antiproliferative effects of radiation in human (MCF-7 and MDA-MB-231) and murine (4T1) breast cancer cells, as well as an immortalized human breast epithelial cell line (MCF-10A). WIN2 or radiation alone inhibited breast tumor growth, while the combination of WIN2 and radiation was more effective than either agent alone in …

The Omega-3 Fatty Acid Eicosapentaenoic Acid Is Required For Normal Alcohol Response Behaviors In C. Elegans, Richard C. Raabe, Laura D. Mathies, Andrew G. Davies, Jill C. Bettinger

Pharmacology and Toxicology Publications

Alcohol addiction is a widespread societal problem, for which there are few treatments. There are significant genetic and environmental influences on abuse liability, and understanding these factors will be important for the identification of susceptible individuals and the development of effective pharmacotherapies. In humans, the level of response to alcohol is strongly predictive of subsequent alcohol abuse. Level of response is a combination of counteracting responses to alcohol, the level of sensitivity to the drug and the degree to which tolerance develops during the drug exposure, called acute functional tolerance. We use the simple and well-characterized nervous system of Caenorhabditis …

Specific Localization Of Β-Arrestin2 In Myenteric Plexus Of Mouse Gastrointestinal Tract, Hercules T. Maguma, Dipanjana D. De, Sukhada Bhave, William L. Dewey, Hamid I. Akbarali

Pharmacology and Toxicology Publications

Abstract

β-arrestin2 is a key molecule involved in signaling and internalization of activated G protein-coupled receptors including µ-opioid receptors (MOR). Previously we have shown that decreased expression of β-arrestin2 upon chronic morphine is associated with the development of opioid tolerance in the gastrointestinal tract. However, the localization of β-arrestin2 within the gastrointestinal wall is not known. In this study we found that β-arrestin2 is localized in the soma of a select group of neurons in the myenteric ganglia but not in smooth muscle. The density of β-arestin2 was significantly higher in the ileum than the colon. We identified four variants …

Activation Of Nlrp3 Inflammasomes Enhances Macrophage Lipid-Deposition And Migration: Implication Of A Novel Role Of Inflammasome In Atherogenesis, Xiang Li, Yang Zhang, Min Xia, Erich Gulbins, Krishna M. Boini, Pin-Lan Li

Pharmacology and Toxicology Publications

Although Nlrp3 inflammasome activation in macrophages has been shown to be critical for the development of atherosclerosis upon atherogenic stimuli, it remains unknown whether activated Nlrp3 inflammasomes by other non-atherogenic stimuli induce alterations in macrophages that may contribute in the concert with other factors to atherogenesis. Thus, the present study tested the hypothesis that activation of Nlrp3 inflammasomes by ATP, which is a classical non-lipid danger stimulus, enhances the migration of macrophage and increases lipids deposition in macrophages accelerating foam cell formation. We first demonstrated that extracellular ATP (2.5 mM) markedly increased the formation and activation of Nlrp3 inflammasomes in …

An Analysis Of Fatty Acid Metabolism’S Role In The Development Of Acute Functional Tolerance To Ethanol In Caenorhabditis Elegans, Richard Raabe

Theses and Dissertations

An individual’s naïve level of response (LR) to ethanol is predictive of their lifetime likelihood to abuse alcohol. LR is heavily genetically influenced, suggesting that the genes responsible for LR may also be central to the development of abuse disorders. Our laboratory uses the model organism C. elegans to investigate the genetic influences on responses to acute ethanol exposure. We recently found that changes in TAG levels can alter LR. From this result we investigated the role of long-chain polyunsaturated fatty acids (LC-PUFAs) as well enzymes involved in lipid modifications of proteins. We found that LC-PUFAs are necessary for acute …