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Investigating A Model For Fetal Alcohol Damage In Caenorhabditis Elegans, Lindsay Kondo Nov 2012

Investigating A Model For Fetal Alcohol Damage In Caenorhabditis Elegans, Lindsay Kondo

Theses and Dissertations

Alcohol use and abuse has many harmful effects, especially to children exposed prenatally, including fetal alcohol spectrum disorders (FASDs). The disabilities due to fetal alcohol exposure continue throughout life and cause major financial burdens to society. The molecular mechanisms underlying FASDs are not well understood. We have taken a genetic approach to characterize ethanol’s effect on changing a discrete cell fate decision during embryogenesis in the nematode, Caenorhabditis elegans (C. elegans). Our preliminary data suggest that ethanol can affect the development of AWC neurons, a pair of olfactory neurons in C. elegans. We suggest that lipids can protect AWC neurons …


Role Of Tyrosyl-Dna Phosphodiesterase (Tdp 1) On Repair Of 3′-Phosphoglycolate (3′- Pg) Terminated Dna Double-Strand Breaks (Dsbs) And In Response To Oxidative Stress, Tong Zhou Nov 2012

Role Of Tyrosyl-Dna Phosphodiesterase (Tdp 1) On Repair Of 3′-Phosphoglycolate (3′- Pg) Terminated Dna Double-Strand Breaks (Dsbs) And In Response To Oxidative Stress, Tong Zhou

Theses and Dissertations

DNA DSBs are most toxic to cells because they can lead to genomic rearrangements and even cell death. Most DSBs induced by ionizing radiation or radiomimetic drugs such as calicheamicin and bleomycin, bear 3′-phosphate or 3′- PG moieties that must be removed to allow subsequent gap filling and ligation. DSBs can be repaired by two main pathways: the homologous recombination (HR) pathway and the non-homologous end-joining (NHEJ) pathway, NHEJ is the primary repair pathway in mammalian cells. While HR repairs single strand breaks (SSBs) or DSBs accurately by using an undamaged copy of the sequence mostly at late S phase …


The Role Of Magl Inhibition In Nicotine Withdrawal And Reward, Pretal Muldoon Nov 2012

The Role Of Magl Inhibition In Nicotine Withdrawal And Reward, Pretal Muldoon

Theses and Dissertations

ROLE OF MAGL INHIBITION IN NICOTINE WITHDRAWAL AND REWARD. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. by Pretal Ishvarlal Patel Muldoon Director: M. Imad Damaj, PhD Professor, Department of Pharmacology and Toxicology Tobacco use is one of the leading causes of preventable deaths worldwide. Nicotine, the main psychoactive component of tobacco, sustains and initiates tobacco addiction. Cessation of nicotine induces a dependence withdrawal syndrome. Recent in vivo studies indicate that the endocannabinoid (EC) system modulates both nicotine reward and withdrawal. The purpose of this proposal is to …


Role Of Autophagy In The Response Of Hs578t Breast Tumor Cells To Radiation, Shweta Chakradeo Sep 2012

Role Of Autophagy In The Response Of Hs578t Breast Tumor Cells To Radiation, Shweta Chakradeo

Theses and Dissertations

Breast cancer is the most commonly observed cancer type in women and is the second leading cause of cancer death in women. Radiation can be used to debulk tumors prior to surgery as well as to treat patients after surgery and/or chemotherapy. Previous studies from our laboratory have shown that the anti –malarial drug chloroquine sensitizes breast cancer cell lines to radiation by suppression of autophagy which is a conservative catabolic process that can be cytoprotective. The scientific literature has demonstrated that many tumor cell systems undergo cytoprotective autophagy and that pharmacological or genetic inhibition of autophagy leads to other …


Role Of Nicotinic Acetylcholine Receptors In Experimental Colitis, Shakir Alsharari Aug 2012

Role Of Nicotinic Acetylcholine Receptors In Experimental Colitis, Shakir Alsharari

Theses and Dissertations

Substantial evidence in the literature shows that tobacco smoking has complex and divergent effects on inflammatory bowel diseases (IBD). It ameliorates ulcerative colitis (UC); whereas it aggravates the risk of Crohn’s disease (CD) and affects the disease course and severity. Studies have shown that nicotine has a positive influence on symptoms of UC. Also, it is demonstrated that nicotinic acetylcholine receptor, especially α7 subunit plays an essential component in the vagus nerve-based cholinergic anti-inflammatory effects. In the present study, we explored the effect of nicotine and α7 nicotinic agonists treatment in the DSS colitis mouse model. We also investigated the …


Development Of Natural Cyclic Peptide Inhibitors Of Xrcc4/Xlf Interaction For Radio-Sensitization Of Breast Tumor Cells, Mohaini Mohammed Al Jul 2012

Development Of Natural Cyclic Peptide Inhibitors Of Xrcc4/Xlf Interaction For Radio-Sensitization Of Breast Tumor Cells, Mohaini Mohammed Al

Theses and Dissertations

Breast cancer is the second leading cause of cancer death in women according to the American Cancer Society. The standard treatment regimen for breast cancer involves ionizing radiation combined with surgery and chemotherapy. Ionizing radiation induces a complex signaling response in cells resulting in either growth arrest, senescence or cell death, and the cell killing after exposure to radiation results largely from DNA double-strand breaks (DSBs). There are two main mechanisms in mammalian cells responsible for repairing the DSBs; the primary mechanism is non-homologous end joining (NHEJ) and the secondary mechanism is homologous recombination (HRR). Previous studies showed that breast …


Cell Death And Growth Arrest Pathways Mediating The Actions Of Stilbene 5c In Hct-116 Colon Cancer Cells, Moureq Alotaibi Jul 2012

Cell Death And Growth Arrest Pathways Mediating The Actions Of Stilbene 5c In Hct-116 Colon Cancer Cells, Moureq Alotaibi

Theses and Dissertations

Abstract The stilbene derivative, cis-3, 4’, 5-trimethoxy-3’-aminostilbene (stilbene 5c), is a potentially potent antitumor agent that acts via binding to the colchicine-binding pocket in microtubules. Earlier studies have shown that stilbene 5c induces cell death in ovarian cancer cells and leukemic cells. The present study was designed to investigate the effectiveness of this microtubule poison against the HCT-116 human colon cancer cell line and its mechanisms of action. Time course studies demonstrated that stilbene 5c produces a biphasic decrease in cell viability. The capacity of the cells to proliferate was not restored upon removal of the drug after 6 days …


The Antinociceptive Effects Of Alpha 7 Nicotinic Acetylcholine Receptor Positive Allosteric Modulators In Different Animal Pain Models, Kelen Freitas May 2012

The Antinociceptive Effects Of Alpha 7 Nicotinic Acetylcholine Receptor Positive Allosteric Modulators In Different Animal Pain Models, Kelen Freitas

Theses and Dissertations

The α7 nicotinic acetylcholine receptor (nAChR) subtype is abundantly expressed in the central nervous system (CNS) and in the periphery. Positive allosteric modulators (PAMs) of the α7 increase the response to an agonist and are divided into two types depending on whether they also decrease desensitization of the receptor (type II) or not (type I). Therefore, this study aims to investigate whether the enhancement of endogenous α7 nAChR function will result in a beneficial effect in nociceptive, inflammatory and chronic neuropathic pain models. While NS1738 and PNU-120596 were not active to reduce acute thermal pain, measured by hot-plate and tail-flick …


Radiation Sensitization Of Breast Cancer Cells By Vitamin D Through The Promotion Of Autophagic Cell Death, Eden Wilson May 2012

Radiation Sensitization Of Breast Cancer Cells By Vitamin D Through The Promotion Of Autophagic Cell Death, Eden Wilson

Theses and Dissertations

Radiation therapy is a widely used tool in cancer therapy and is frequently offered as the first line of treatment for cancers of the breast. While radiotherapy is often initially effective in killing tumor cells or suppressing their growth, there are factors that confer tumor cell resistance to irradiation. Development of resistance may lead to disease recurrence despite the use of surgery, chemotherapy and radiation therapy. A primary goal of the studies in Dr. Gewirtz’s laboratory is to develop strategies to overcome resistance to radiation (and chemotherapy) in breast cancer, with the ultimate goal of preventing or attenuating disease recurrence. …


Hydrogen Sulfide As An Allosteric Modulator Of Atp Sensitive Potassium Channels In Colonic Inflammation., Aravind Gade Apr 2012

Hydrogen Sulfide As An Allosteric Modulator Of Atp Sensitive Potassium Channels In Colonic Inflammation., Aravind Gade

Theses and Dissertations

The ATP sensitive potassium channel (KATP) in mouse colonic smooth muscle cell is a complex containing a pore forming subunit (Kir6.1) and a sulfonyl urea receptor subunit (SUR2B). These channels are responsible for maintaining the cellular excitability of the smooth muscle cell which in turn regulates the motility patterns in the colon. We used whole-cell voltage-clamp techniques to study the alterations in these channels in smooth muscle cells in experimental model of colitis (colonic inflammation). Colitis was induced in BALB/C mice following an intracolonic administration of trinitrobenzene sulfonic acid (TNBS). KATP currents were measured at Vh -60 mV in high …


Myelin Gene Expression: Implications For Alcohol Abuse And Dependence, Sean Farris Mar 2012

Myelin Gene Expression: Implications For Alcohol Abuse And Dependence, Sean Farris

Theses and Dissertations

Acute behavioral responses to ethanol have predictive value for determining an individual's risk of long-term drinking behavior. Although the neurobiology of alcohol abuse is complex, prior studies from our laboratory demonstrated differential myelin-associated gene expression (MAGE) in medial prefrontal cortex (PFC) as one potential mechanism influencing acute ethanol behaviors between C57BL/6J (B6) and DBA/2J (D2) mice. Our laboratory and others have also shown MAGE is reduced in PFC of alcoholics. Herein, I have extended these findings through expression profiling of PFC into chronic models of ethanol self-administration from non-human primates and mice. Together, these results suggest that regulation of MAGE …


Antinociceptive Effects Of Monoamine Reuptake Inhibitors In Assays Of Pain-Stimulated And Pain-Depressed Behaviors, Marisa Rosenberg Mar 2012

Antinociceptive Effects Of Monoamine Reuptake Inhibitors In Assays Of Pain-Stimulated And Pain-Depressed Behaviors, Marisa Rosenberg

Theses and Dissertations

ANTINOCICEPTIVE EFFECTS OF MONOAMINE REUPTAKE INHIBITORS IN ASSAYS OF PAIN-STIMULATED AND PAIN-DEPRESSED BEHAVIOR By Marisa B. Rosenberg A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University. Virginia Commonwealth University, 2012 Advisor: Sidney Stevens Negus, Ph.D. Professor, Department of Pharmacology/Toxicology Noxious stimuli can produce pain-related stimulation of some behaviors (e.g. withdrawal responses) and depression of other behaviors (e.g. feeding, locomotion, responding maintained by many types of positive reinforcement). Monoamine reuptake inhibitors are used clinically to treat depression and to manage some types of pain. This study examined the antinociceptive properties …


Elevating Endogenous Cannabinoids Reduces Opioid Withdrawal In Mice, Divya Ramesh Feb 2012

Elevating Endogenous Cannabinoids Reduces Opioid Withdrawal In Mice, Divya Ramesh

Theses and Dissertations

Delta9-tetrahydrocannbinol (THC), the primary active constituent of Cannabis sativa, has long been known to reduce opioid withdrawal symptoms. Although THC produces most of its pharmacological actions through the activation of CB1 and CB2 cannabinoid receptors, the role these receptors play in reducing opioid withdrawal symptoms remains unknown. The endogenous cannabinoids, N-arachidonoylethanolamine (anandamide; AEA) and 2-arachidonylglycerol (2-AG), activate both cannabinoid receptors, but are rapidly metabolized by fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), respectively. The objective of this dissertation was to test whether increasing AEA or 2-AG, via inhibition of their respective hydrolytic enzymes, reduces morphine withdrawal symptoms in …


Dynamics Of Substrate Interactions In Trna (M1g37) Methyltransferase: Implications For Drug Discovery, Maria Kiouppis Palesis Feb 2012

Dynamics Of Substrate Interactions In Trna (M1g37) Methyltransferase: Implications For Drug Discovery, Maria Kiouppis Palesis

Theses and Dissertations

The bacterial enzyme t-RNA (m1G37) methyltransferase (TrmD) is an ideal anti-microbial drug target since it is found in all eubacteria, serves an essential role during protein synthesis, and shares very little sequence or structural homology with its eukaryotic counterpart, Trm5. TrmD, a homodimeric protein, methylates the G37 nucleotide of tRNA using S-adenosyl-L-methionine (SAM) as the methyl donor and thus enables proper codon-anticodon alignment during translation. The two deeply buried binding sites for SAM seen in X-ray crystallography suggest that significant conformational changes must occur for substrate binding and catalytic turnover. Results from molecular dynamics simulations implicate a flexible loop region …


Targeting The Endocannabinoid System To Reduce Inflammatory Pain, Sudeshna Ghosh Jan 2012

Targeting The Endocannabinoid System To Reduce Inflammatory Pain, Sudeshna Ghosh

Theses and Dissertations

The endogenous cannabinoids (endocannabinoids) anandamide (AEA) and 2-arachidonylglycerol (2-AG) exert their effects predominantly through cannabinoid CB1 and CB2 receptors, but these actions are short-lived because of rapid hydrolysis by fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), respectively. Selective inhibition of either enzyme elevates CNS levels of the appropriate endocannabinoid and produces analgesic effects with fewer psychomimetic side effects than Δ9-tetrahydrocannabinol (THC), the primary active constituent of marijuana. While cannabinoid receptor agonists and FAAH inhibitors reliably produce anti-inflammatory and anti-hyperalgesic effects in the carrageenan test and other inflammatory pain models, much less is known about the consequences of inhibiting …


Artemis And Metnase Mediated Processing Of 3΄-Blocked Dna Lesions: Role In Radio/Chemoresistance And Dna Repair, Susovan Mohapatra Jan 2012

Artemis And Metnase Mediated Processing Of 3΄-Blocked Dna Lesions: Role In Radio/Chemoresistance And Dna Repair, Susovan Mohapatra

Theses and Dissertations

DNA double-strand breaks (DSB) with chemically modified end-termini are the most significant lesions resulting from radio/chemotherapeutic intervention of cancer and non homologous end-joining (NHEJ) factor Artemis nuclease has been implicated in the repair of such breaks. To examine whether the resolution of terminally blocked DNA DSBs is the biologically relevant function of Artemis, Artemis deficient fibroblasts were stably complemented with wild type or an endonuclease deficient D165N mutant Artemis. Physiological levels of wild type (WT) Artemis completely restored DSB repair proficiency and resistance to γ-radiation, bleomycin, and neocarzinostatin. Cells expressing the D165N mutants remained as chemo/radiosensitive and as repair deficient …


Investigating The Role Of Α6 And Α4 Containing Neuronal Nicotinic Acetylcholine Receptors In Nicotine And Cocaine Conditioned Place Preference Tests In Mice., Sarah Sanjakdar Jan 2012

Investigating The Role Of Α6 And Α4 Containing Neuronal Nicotinic Acetylcholine Receptors In Nicotine And Cocaine Conditioned Place Preference Tests In Mice., Sarah Sanjakdar

Theses and Dissertations

Neuronal nicotinic acetylcholine receptors modulate both cholinergic and non-cholinergic synaptic transmission. Our research concerns α6 and α4 neuronal nicotinic subunits because they often co-assemble with the β2 subunit, which has abundant expression in the CNS and previous work has demonstrated that β2* nAChRs are involved in nicotine and cocaine reward. α6β2* and α4β2* nAChRs are highly expressed in midbrain, which is known to be critical for the incentive salience associated with natural and artificial (drug) reward. Our goal was to assess the role of α6β2* and α4β2* nAChRs in nicotine and cocaine reward using an unbiased conditioned place preference (CPP) …


The Role Of High Affinity Nicotinic Acetylcholine Receptors On Anxiety-Like Behavior: A Study In Female Mice, Jessicka Hall Jan 2012

The Role Of High Affinity Nicotinic Acetylcholine Receptors On Anxiety-Like Behavior: A Study In Female Mice, Jessicka Hall

Theses and Dissertations

Tobacco dependence is high in women who suffer from anxiety disorders yet little is known about the contributions of nicotinic acetylcholine receptors (nAChRs) on anxiety-like behavior. β2*nAChRs (*denotes assembly with other subunits) are the most abundantly expressed nAChRs in the brain yet little is known about the contributions of β2*nAChRs on anxiety-like behavior in female mice. In this study, antagonism and nicotine effects on anxiety-like behavior was investigated across the life span in 6, 12 and 24-month-old drug-naïve knockout (KO), heterozygous (HET) and a gain of function α6L9S mice and wild type (WT). HET mice showed increased sensitivity to di-hydrobeta-erythroidine …