Medical Toxicology Commons^™

Effects Of Storage Time On Glycolysis In Donated Human Blood Units, Zhen Qi, John D. Roback, Eberhard O. Voit

Toxicology and Cancer Biology Faculty Publications

Background: Donated blood is typically stored before transfusions. During storage, the metabolism of red blood cells changes, possibly causing storage lesions. The changes are storage time dependent and exhibit donor-specific variations. It is necessary to uncover and characterize the responsible molecular mechanisms accounting for such biochemical changes, qualitatively and quantitatively; Study Design and Methods: Based on the integration of metabolic time series data, kinetic models, and a stoichiometric model of the glycolytic pathway, a customized inference method was developed and used to quantify the dynamic changes in glycolytic fluxes during the storage of donated blood units. The method provides a …

Latexin Inactivation Enhances Survival And Long-Term Engraftment Of Hematopoietic Stem Cells And Expands The Entire Hematopoietic System In Mice, Yi Liu, Cuiping Zhang, Zhenyu Li, Chi Wang, Jianhang Jia, Tianyan Gao, Gerhard C. Hildebrandt, Daohong Zhou, Subbarao Bondada, Peng Ji, Daret K. St. Clair, Jinze Liu, Chang-Guo Zhan, Hartmut Geiger, Shuxia Wang, Ying Liang

Toxicology and Cancer Biology Faculty Publications

Natural genetic diversity offers an important yet largely untapped resource to decipher the molecular mechanisms regulating hematopoietic stem cell (HSC) function. Latexin (Lxn) is a negative stem cell regulatory gene identified on the basis of genetic diversity. By using an Lxn knockout mouse model, we found that Lxn inactivation in vivo led to the physiological expansion of the entire hematopoietic hierarchy. Loss of Lxn enhanced the competitive repopulation capacity and survival of HSCs in a cell-intrinsic manner. Gene profiling of Lxn-null HSCs showed altered expression of genes enriched in cell-matrix and cell-cell interactions. Thrombospondin 1 (Thbs1 …

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced …

A Novel Redox Regulator, Mntnbuoe-2-Pyp5+, Enhances Normal Hematopoietic Stem/Progenitor Cell Function, Yanming Zhao, Dustin W. Carroll, Y. You, Luksana Chaiswing, R. Wen, I. Batinic-Haberle, Subbarao Bondada, Ying Liang, Daret K. St Clair

Toxicology and Cancer Biology Faculty Publications

The signaling of reactive oxygen species (ROS) is essential for the maintenance of normal cellular function. However, whether and how ROS regulate stem cells are unclear. Here, we demonstrate that, in transgenic mice expressing the human manganese superoxide dismutase (MnSOD) gene, a scavenger of ROS in mitochondria, the number and function of mouse hematopoietic stem/progenitor cells (HSPC) under physiological conditions are enhanced. Importantly, giving MnTnBuOE-2-PyP⁵⁺(MnP), a redox- active MnSOD mimetic, to mouse primary bone marrow cells or to C57B/L6 mice significantly enhances the number of HSPCs. Mechanistically, MnP reduces superoxide to hydrogen peroxide, which activates intracellular Nrf2 signaling …

Polyubiquitination Of Apurinic/Apyrimidinic Endonuclease 1 By Parkin, Timothy L. Scott, Christina A. Wicker, Rangaswamy Suganya, Bithika Dhar, Thomas A. Pittman, Craig Horbinski, Tadahide Izumi

Toxicology and Cancer Biology Faculty Publications

Apurinic/apyrimidinic endonuclease 1 (APE1) is an essential protein crucial for repair of oxidized DNA damage not only in genomic DNA but also in mitochondrial DNA. Parkin, a tumor suppressor and Parkinson's disease (PD) associated gene, is an E3 ubiquitin ligase crucial for mitophagy. Although DNA damage is known to induce mitochondrial stress, Parkin's role in regulating DNA repair proteins has not been elucidated. In this study, we examined the possibility of Parkin‐dependent ubiquitination of APE1. Ectopically expressed APE1 was degraded by Parkin and PINK1 via polyubiquitination in mouse embryonic fibroblast cells. PD‐causing mutations in Parkin and PINK1 abrogated APE1 ubiquitination. …

Doxorubicin Cytotoxicity In A Human Proximal Tubular Epithelial Cell Line Was Attenuated By The Natural Product Resveratrol, Morghan Schuyler Getty

Theses, Dissertations and Capstones

The cancer chemotherapeutic agent doxorubicin (DOX), Adriamycin, is part of the treatment regimen for breast, ovarian, small cell lung cancer and acute/chronic lymphoid leukemia. Adverse effects associated with DOX are cardiotoxicity and nephrotoxicity. Interventions are needed to reduce DOX nephrotoxicity. Resveratrol (RES) is a phytochemical contained in grapes, berries and nuts, which possesses antioxidant and anticancer properties. This study tested the hypothesis that RES will attenuate DOX renal cytotoxicity in human noncancerous renal proximal tubular epithelial (HK-2) cells and that RES will reduce DOX mediated changes in mitochondrial function. HK-2 cells were plated and grown for 48 hours (h). Cells …

Uvb Induces Mvp Release In A Paf Dependent Manner In Skin-Dervied Epithelial Cell Line, Langni Liu, Katherine E. Fahy, Christine M. Rapp, Eric J. Romer, Christina E. Borchers, Ji C. Bihl, Jeffrey B. Travers

Pharmacology and Toxicology Faculty Publications

Ultraviolet-B (UVB) irradiation of the skin can result in both acute inflammation and systemic immunosuppression. These effects are mediated by the release of bioactive molecules (e.g. cytokines and lipids) from resident skin epithelial and immune cells. Our lab has previously determined that UVB exposure stimulates the production of an inflammatory phospholipid activator, platelet-activating factor (PAF) and its oxidized analogs, which are involved in mediating the UVB responses. Due to the fact that UVB radiation is absorbed by the epidermis but causes systemic effects, we are interested in examining the PAF-mediated mechanisms of systemic intercellular communication. Microvesicle particles (MVP) are small …

From Dose To Response: In Vivo Nanoparticle Processing And Potential Toxicity, Uschi M. Graham, Gary Jacobs, Robert A. Yokel, Burtron H. Davis, Alan K. Dozier, M. Eileen Birch, Michael T. Tseng, Günter Oberdörster, Alison Elder, Lisa Delouise

Pharmaceutical Sciences Faculty Publications

Adverse human health impacts due to occupational and environmental exposures to manufactured nanoparticles are of concern and pose a potential threat to the continued industrial use and integration of nanomaterials into commercial products. This chapter addresses the inter-relationship between dose and response and will elucidate on how the dynamic chemical and physical transformation and breakdown of the nanoparticles at the cellular and subcellular levels can lead to the in vivo formation of new reaction products. The dose-response relationship is complicated by the continuous physicochemical transformations in the nanoparticles induced by the dynamics of the biological system, where dose, bio-processing, and …

Nucleotide Excision Repair: Impacts Of Environmental Carcinogens And Its Role In Cancer Susceptibility In Appalachian Kentucky, Nathaniel C. Holcomb

Theses and Dissertations--Toxicology and Cancer Biology

Lung cancer is a particularly devastating disease, accounting for the most deaths among all cancer types in the United States. Despite a reduction in the country’s smoking rates, cigarette smoking remains the number one risk factor for lung cancer. Additionally arsenic exposure, which occurs primarily through contaminated drinking water in the U.S., is associated with increased lung cancer incidence. The nucleotide excision repair (NER) pathway is critical for maintenance of genomic fidelity, removing DNA lesions that could otherwise promote DNA mutations and drive carcinogenesis. Tobacco smoking introduces significant amounts of DNA damage and produces characteristic DNA mutations found in lung …

Changes In Mitochondrial Homeostasis And Redox Status In Astronauts Following Long Stays In Space, Hiroko P. Indo, Hideyuki J. Majima, Masahiro Terada, Shigeaki Suenaga, Kazuo Tomita, Shin Yamada, Akira Higashibata, Noriaki Ishioka, Takuro Kanekura, Ikuya Nonaka, Clare L. Hawkins, Michael J. Davies, Daret K. St Clair, Chiaki Mukai

Toxicology and Cancer Biology Faculty Publications

The effects of long-term exposure to extreme space conditions on astronauts were investigated by analyzing hair samples from ten astronauts who had spent six months on the International Space Station (ISS). Two samples were collected before, during and after their stays in the ISS; hereafter, referred to as Preflight, Inflight and Postflight, respectively. The ratios of mitochondrial (mt) to nuclear (n) DNA and mtRNA to nRNA were analyzed via quantitative PCR. The combined data of Preflight, Inflight and Postflight show a significant reduction in the mtDNA/nDNA in Inflight, and significant reductions in the mtRNA/nRNA ratios in both the Inflight and …

Analysis Of Rna Expression Of Normal And Cancer Tissues Reveals High Correlation Of Cop9 Gene Expression With Respiratory Chain Complex Components, Christina A. Wicker, Tadahide Izumi

Toxicology and Cancer Biology Faculty Publications

BACKGROUND: The COP9 signalosome, composed of eight subunits, is implicated in cancer genetics with its deneddylase activity to modulate cellular concentration of oncogenic proteins such as IkB and TGFβ. However, its function in the normal cell physiology remains elusive. Primarily focusing on gene expression data of the normal tissues of the head and neck, the cancer genome atlas (TCGA) database was used to identify groups of genes that were expressed synergistically with the COP9 genes, particularly with the COPS5 (CSN5), which possesses the catalytic activity of COP9.

RESULTS: Expressions of seven of the COP9 genes (COPS2, COPS3, COPS4, COPS5, COPS6, …

The Role Of Nicotine, A7 Nicotinic Acetylcholine Receptors And Extracellular Matrix Remodeling In Pulmonary Fibrosis., Glenn Ward Vicary

Electronic Theses and Dissertations

The median survival for idiopathic pulmonary fibrosis (IPF) patients from diagnosis is a dismal 3 years. This condition is characterized by pulmonary fibroproliferation and excess production and disordered deposition of extracellular matrix (ECM) proteins resulting in obliteration of the original tissue architecture, loss of lung function and eventual death due to respiratory failure. The main hindrance to the development of effective treatments against pulmonary fibrosis is the late detection of its progression and is often of unknown cause. Tobacco smoke represents the most important environmental factor linked to the development of pulmonary fibrosis, with over 60% of IPF patients current …

Toxic Environmental Exposures And Kidney Health In Children., Darcy K. Weidemann, Virginia M. Weaver, Jeffrey J. Fadrowski

Manuscripts, Articles, Book Chapters and Other Papers

High-level exposures to a number of agents are known to have direct nephrotoxic effects in children. A growing body of literature supports the hypothesis that chronic, relatively low-level exposure to various nephrotoxicants may also increase the risk for chronic kidney disease (CKD) or accelerate its progression. In this review we highlight several environmental nephrotoxicants and their association with CKD in children and adolescents. We also discuss unique epidemiological challenges in the use of kidney biomarkers in environmental nephrotoxicology.

Effect Of Genipin On Cisplatin- Induced Nephrotoxicity, Eglal Orner Mahgoub

Theses

Cisplatin (CSP) is a potent and widely used chemotherapeutic agent. However, clinical efficacy of CSP is compromised due to the elicitation of nephrotoxicity and ototoxicity. In this study, I have investigated the nephroprotective effects of a phytochemical – genipin (GP) isolated from gardenia flower (Gardenia jasminoides), on a murine model of cisplatin-induced nephropathy. CSP-induced renal tissue injury was characterized by elevated levels of serum blood urea nitrogen (BUN), creatinine (Cr) and cystatin-C. In addition, levels of kidney injury molecule-1 (KIM-1) were increased in the renal tissues of CSP administered animals. CSP also induced renal oxidative stress, evidenced by increased NADPH …

Neprilysin Is A Mediator Of Alternative Renin-Angiotensin-System Activation In The Murine And Human Kidney, Oliver Domenig, Arndt Manzel, Nadja Grobe, Eva Königshausen, Christopher C. Kaltenecker, Johannes J. Kovarik, Susan B. Gurley, Dunja Van Oyen, Marlies Antlanger, Michael Bader, Daisy Motta-Santos, Jose Carlos Santos, Robson A. Santos, Khalid M. Elased, Marcus D. Säemann, Ralf A. Linker, Marko Poglitsch

Pharmacology and Toxicology Faculty Publications

Cardiovascular and renal pathologies are frequently associated with an activated renin-angiotensin-system (RAS) and increased levels of its main effector and vasoconstrictor hormone angiotensin II (Ang II). Angiotensin-converting-enzyme-2 (ACE2) has been described as a crucial enzymatic player in shifting the RAS towards its so-called alternative vasodilative and reno-protective axis by enzymatically converting Ang II to angiotensin-(1-7) (Ang-(1-7)). Yet, the relative contribution of ACE2 to Ang-(1-7) formation in vivo has not been elucidated. Mass spectrometry based quantification of angiotensin metabolites in the kidney and plasma of ACE2 KO mice surprisingly revealed an increase in Ang-(1-7), suggesting additional pathways to be responsible for …

Simultaneous Quantitation Of Oxidized And Reduced Glutathione Via Lc-Ms/Ms: An Insight Into The Redox State Of Hematopoietic Stem Cells, Dustin W. Carroll, Diana Howard, Haining Zhu, Christian M. Paumi, Mary Vore, Subbarao Bondada, Ying Liang, Chi Wang, Daret K. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cellular redox balance plays a significant role in the regulation of hematopoietic stem-progenitor cell (HSC/MPP) self-renewal and differentiation. Unregulated changes in cellular redox homeostasis are associated with the onset of most hematological disorders. However, accurate measurement of the redox state in stem cells is difficult because of the scarcity of HSC/MPPs. Glutathione (GSH) constitutes the most abundant pool of cellular antioxidants. Thus, GSH metabolism may play a critical role in hematological disease onset and progression. A major limitation to studying GSH metabolism in HSC/MPPs has been the inability to measure quantitatively GSH concentrations in small numbers of HSC/MPPs. Current methods …

Developing A More Clinically-Relevant Mouse Model Of Cisplatin-Induced Nephrotoxicity., Cierra N. Sharp

Electronic Theses and Dissertations

Cisplatin is a nephrotoxic chemotherapeutic that causes acute kidney injury (AKI) in 30% of patients. Although recovery can occur after one episode of cisplatin-induced AKI, studies have indicated multiple episodes may lead to the development of chronic kidney disease (CKD), an irreversible disease with no current treatments. The standard mouse model of cisplatin-induced AKI consists of one, high dose of cisplatin (> 20 mg/kg) that is lethal to the animal three days later. This model doesn’t accurately reflect the repeated dosing regimen patients receive, and doesn’t allow for long-term outcome studies of pathologies associated with CKD. We have developed a …

Exposure Of Human Lung Cells To Tobacco Smoke Condensate Inhibits The Nucleotide Excision Repair Pathway, Nathaniel C. Holcomb, Mamta Goswami, Sung Gu Han, Samuel Clark, David K. Orren, C. Gary Gairola, Isabel Mellon

Toxicology and Cancer Biology Faculty Publications

Exposure to tobacco smoke is the number one risk factor for lung cancer. Although the DNA damaging properties of tobacco smoke have been well documented, relatively few studies have examined its effect on DNA repair pathways. This is especially true for the nucleotide excision repair (NER) pathway which recognizes and removes many structurally diverse DNA lesions, including those introduced by chemical carcinogens present in tobacco smoke. The aim of the present study was to investigate the effect of tobacco smoke on NER in human lung cells. We studied the effect of cigarette smoke condensate (CSC), a surrogate for tobacco smoke, …

Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson

Biomedical Engineering Undergraduate Honors Theses

Amyloid Beta (Aβ) was the major focus of this study. It is a peptide that is present in the brain with a high tendency to self-aggregate. When this protein aggregates, it forms oligomers and protofibrils which in turn are deposited as senile plaques in the brain. The reason for the concern with these plaques is their association with the neurological disorder Alzheimer’s disease. It has been found that the most dangerous oligomers are formed in a portion of the plasma membrane known as lipid rafts. The purpose of this study was to understand how micelles affect the aggregation properties of …

Role Of Phosphodiesterase-4 In Alcohol-Induced Organ Injury., Diana Veronica Avila

Electronic Theses and Dissertations

Alcoholic liver disease (ALD) remains a leading cause of death from liver disease in the U.S., and there is still no FDA-approved therapy. Alcohol metabolism leads to generation of free radicals and oxidative stress with a resultant formation of lipid peroxidation products, which, in turn, contribute to the development of ALD. Alcohol induced hepatic steatosis is the earliest and most frequent manifestation of ALD and a significant risk factor for progressive liver disease. Cyclic adenosine monophosphate (cAMP) signaling has been shown to significantly regulate lipid metabolism. Moreover, agents that increase cAMP have been shown to effectively mitigate oxidative stress both …