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Record Count: 11
To sort columns alphabetically or numerically, click on the column
header (Title, Principal Investigator, Institution, City, ST, Award Code, or
Pubs).
DESCRIPTION (provided by applicant): Oxidative damage caused by the release of cytokines is thought to play a major role in this cellular response to injury. Mitochondrial DNA (mtDNA) is one of the critical targets of this damage. Therefore, this competitive renewal will remain focused on the mechanisms by which cells of the central nervous system, particularly oligodendrocytes, deal with such genotoxic insults. Our overall working hypothesis is that acceptable lesion equilibrium is maintained within the mtDNA of cells through a combination of reactions that result in a balance between mtDNA damage and mtDNA repair. If this lesion equilibrium is shifted such that the damage exceeds the repair capacity, fewer functioning mitochondrial genomes will be available for transcription and cellular bioenergetics will decrease. The cell will then either adapt to accommodate to this change in lesion equilibrium or, if the damage becomes excessive, mitochondrial function will cease and the cell will undergo death by either necrosis or apoptosis. During the previous funding period, we have shown that enhanced mtDNA repair can protect oligodendrocytes from damage generated by cytokines. Consequently, we hypothesize that enhanced mtDNA repair will ameliorate the development and progression of radiation-induced brain injury. This hypothesis will be tested through the pursuit of the following two specific aims. In aim one; we will develop a therapeutic approach for protecting glial cells from oxidative stress by targeting DNA repair enzymes to the mitochondria. These studies will use primary cultures of oligodendrocytes to optimize the delivery to mitochondria of recombinant mtDNA repair enzymes in order to enhance mtDNA repair and provide protection from genotoxic insults. In aim two, we will test the therapeutic efficacy of enhanced mtDNA repair in a clinically relevant model of radiation-induced cognitive impairment. These studies will use an animal model to help determine whether the strategies developed in the first aim can be used therapeutically for protection of the CNS from oxidative insults. When successfully completed, these studies will provide novel information which will form the groundwork for developing a new strategy for preventing the debilitating dementia that results from radiation therapy for brain tumors.
DESCRIPTION (provided by applicant): This is the competitive renewal of a grant which has been continuously funded for the past 23 years. During this time, we have made novel discoveries in the area of mitochondrial DNA damage and repair and how these processes play an important role in the pathogenesis of disease. The present application uses this work as a foundation to design new translational studies intended to develop innovative protocols to enhance the protection of this DNA in mitochondria. These strategies will be designed to block or delay the onset of type I diabetes and to protect islets used for transplantation against the loss of function and viability that occurs during islet isolation and in the early transplantation period. The first aim is designed to mechanistically evaluate and optimize the delivery of recombinant DNA repair enzymes and antioxidants to mitochondria in
¿-cells by protein transduction. These studies are structured to develop a more thorough understanding of the mechanisms involved in the protection of ¿-cells by protein transduction and to optimize the delivery of recombinant DNA repair and antioxidant proteins into mitochondria of ¿-cells by the TAT peptide. The second aim will evaluate the effects of the recombinant proteins developed in the first aim on the pathogenesis of diabetes in two animal models of type 1 diabetes. These studies are designed to determine whether the most effective recombinant protein or proteins, identified in the first aim to block ¿-cell toxicity caused by ROS, RNS and cytokines, can block the onset of diabetes in two animal models of type I diabetes when delivered into these animals by protein transduction. One animal model to be studied is the NOD mouse because diabetes in these animals appears to result from purely autoimmune mechanisms and recent work with these animals has indicated that there is a role for mtDNA in the pathogenesis of their disease. The second animal model to be studied is that produced by subdiabetogenic doses of the ¿-cell toxin streptozotocin (STZ). Transgenic mice which over-express the recombinant proteins in mitochondria of ¿-cells will be used for proof of principle. This model was chosen because diabetes is initiated by a ¿-cell toxin, STZ, and is associated with islet inflammation which resembles that seen in human type I diabetes. The final aim will evaluate the ability of fusion proteins to enhance the viability of islets to be used for transplantation. Although recently islet transplantation has proven to be a promising approach for the treatment of type I diabetes, this procedure has been plagued with problems relating to islet viability. The studies in this aim will explore whether the fusion proteins developed in the first aim can be used to help overcome this problem.
DESCRIPTION (provided by applicant): It is now recognized that lipid oxidation produces an array of compounds capable of initiating redox cell signaling. Some of the pathways induce apoptosis while others induce the synthesis of proteins which increase the threshold at which oxidative stress and cytotoxicity occurs. Understanding how these responses are distinguished is critical in determining the molecular events that protect the cell against oxidative damage mediated by xenobiotics or during the pathophysiology of disease. In the previous funding period the central focus of this proposal was to define the mechanisms through which oxidized lipids adapt the endothelial cell to oxidative stress using the induction of the intracellular antioxidant glutathione (GSH) as a model. Preliminary data and published observations developed through the previous funding period identified mechanisms through which a specific sub-class of oxidized lipids, those with electrophilic reactive carbon centers, mediate signal transduction. We found that cytoprotection was dependent on the activation of the electrophile response element (also known as the antioxidant response element) which induces the synthesis of cytoprotective proteins such as heme oxygenase and glutamyl cysteine ligase. In the course of these studies we have used a proteomics approach to define the subset of proteins reactive to electrophilic lipids in the cell which we have designated as the electrophile responsive proteome. These data have led to the hypothesis that electrophilic lipids generated during lipid peroxidation control cell function through modification of the proteins that compose the electrophilic responsive proteome. This hypothesis will be tested by pursuit of the following Specific Aims: 1) Determine whether distinct classes of lipid derived electrophilic cyclopentenones react with different members of the electrophile responsive proteome 2) Determine the effect of the activation of endogenous enzymatic sources of lipid oxidation products on the electrophile responsive proteome. 3) Determine the functional impact of the interaction of electrophilic lipids with endothelial cell mitochondria. The information gained from the accomplishment of these specific aims will give insight into the mechanisms of adaptation and cytotoxicity of the endothelium under toxicological and pathological stress.
DESCRIPTION (provided by applicant): Inherited genetic risk accounts for no more than 10-15% of all breast cancer cases, hence it has been suggested that the environment plays a significant role in the cause of this cancer. We have hypothesized that early periods of exposure to hormonally-active chemicals are critical for causing developmental changes to the mammary tissue and that these alterations can set the biochemical "blue-print" that can play an important role in being susceptible for breast cancer as adults. We propose to investigate the potential of prenatal exposure to the bioactive food component, resveratrol, and the environmental contaminant, TCDD, as estrogen agonist and antagonist respectively to alter mammary cancer susceptibility in the adult offspring. Specific aim 1 will be to investigate the potential of resveratrol and TCDD to alter mammary gland development as evaluated from mammary whole mounts and proliferation cell nuclear antigen staining will be used as an index of cell proliferation in mammary glands of resulting 21 day old fetuses and 50 day old adult offspring. Aim 2 will identify proteins that are differentially expressed in mammary glands using 2-D gel electrophoresis and MALDI-TOF spectrometry, followed by immuno-techniques for validation. Characterization of proteins that are differentially modulated will identify novel pathways that play a role in determining cancer susceptibility. Aim 3 will determine the effects of prenatal exposure to resveratrol and TCDD, alone and in combination, for predisposition to chemically-induced mammary cancer using the 7,12 dimethylbenz[a]anthracene-rat model. Also, we will record body and uterine weights, day of vaginal opening and evaluate estrous cyclicity as indicators of endocrine function. Changes in susceptibility to mammary cancer will be correlated with gland development, epithelial and stromal cell proliferation, endocrine status and proteomic signatures. Characterization of novel pathways that are differentially modulated at critical periods will identify key proteins that play a role in determining cancer susceptibility. Programming breast cancer chemoprevention from in utero exposure to a nutritional agent would be a novel breakthrough for women's health.
DESCRIPTION (provided by applicant): Solar ultraviolet B (UVB) radiation is the major risk factor for the induction and development of non-melanoma skin cancer (NMSC) including squamous cell carcinoma (SCCs) and basal cell carcinoma (BCCs) which account for more than one million newly diagnosed human cancers annually in the USA. UVB causes structural alterations in DNA leading to hot spot mutations in tumor suppressor genes such as p53 and ptch in BCCs and in the perilesional skin surrounding these lesions. The pathogenesis of these tumors is thought to be driven by mutational activation of sonic hedgehog (shh) signaling and inactivation of p53 resulting in blockade of apoptosis and augmentation of cell proliferation and clonal expansion of initiated cells prompting the growth of BCCs. In this proposal we will test the hypothesis that the combination of shh activation and p53 inhibition drives the neoplastic process in BCCs and that finding chemical agents targeted to blocking the effects of UVB on these signaling pathways will abrogate the development of these lesions. For this study we will employ genetically engineered cancer-susceptible murine models that mimic the phenotype of tumor-susceptible human skin. These include: ptc1+ hairless mice carrying p53+/+p53+/- or p53-/-; in prior studies we have shown that ptc1+/SKH1 hairless mice carrying p53+/+ spontaneously develop multiple human BCCs-like lesions in addition to rhabdomyosarcomas. Chronic UVB irradiation of the skin of these mice readily induces multiple tumors including papillomas, SCCs and BCCs, providing a uniquely relevant murine model of human skin cancer induction. In this murine model we will investigate effects of targeted anti-cancer agents including cyclopamine and CP-31398, which block shh activation and convert mutant p53 into a functionally active protein respectively. We will also assess the role of nuclear factor kappa B (NFkB), which is also induced by UVB irradiation of the skin, by using sulfasalazine that blocks NFkB activation by directly inhibiting IkB kinases. Employing LC-MS, we have shown that co-administration of cyclopamine and CP-31398 or sulfasalazine does not alter individual agent's bioavailability. It is our belief that these studies will form the basis for translational clinical trials whereby a suitable combination of these test agents could prove highly effective in abrogating BCCs and may provide a mechanism-based uniquely effective approach for the chemoprevention of NMSCs in susceptible human populations.
DESCRIPTION (provided by applicant): This is the first competing renewal of a program project initially funded for three years starting in June 2003. The fundamental goals and innovative structural paradigm of this multi-institution, multi-investigator program remain essentially unchanged. Approximately half of the United States population continues to be impacted by pathogenic air pollutants such as ozone (O3), which recent epidemiologic studies suggest induces long term functional impairments in children. Despite extensive research endeavors, the mechanisms of exposure-related lung injury and how age and exposure history govern acute and chronic susceptibility in the post natal lung remain poorly understood. Novel evidence documents that postnatal, episodic O3 exposure profoundly alters lung growth, structure, and function in non-human primates. Biological effects are likely determined by the combination of O3 intrapulmonary dispersion and reaction/diffusion within the epithelial lining fluid (ELF), leading to generation of the local dose. Thus, the investigators hypothesize that the age-, site-, cell-, and exposure history-related susceptibilities to acute versus episodic O3 result from differences in ELF-dependent interactions associated with spatial heterogeneities in the local dose coupled with differential regulation of the airway epithelial intracellular and ELF antioxidant pools. In lieu of the originally proposed airway sensitization component, the investigators have prioritized our current goals to focus on age, biological variation, and exposure history (including recovery) related susceptibilities. The investigators' efforts will advance understanding of the fundamental mechanisms of O3-related disruption of normal lung development, lung injury, and susceptibility; and generate unique characterizations of lung structure and biochemistry. The interdisciplinary research team encompasses expertise in lung surface chemistry, pathobiology and quantitative morphology, imaging and 3-dimensional reconstruction, dosimetry, extrapolation modeling, and biostatistics. This highly interactive program will utilize non-human primates (rhesus monkeys) and, to expand the database, rats, and encompasses interdependent projects (4) and cores (3). the investigators intend to characterize the ELF-mediated local dose generation; define the mechanisms of postnatal susceptibility; characterize airway response determinants as a function of acute versus episodic exposures; develop lung injury biomarkers utilizing the nose as a sentinel; build structural atlases extracted from 3-D reconstructions, and, formulate models that predict health outcomes. The program spans from molecular interactions to the intact primate, is highly relevant to NIEHS goals, is anticipated to extend into the human population, and will substantially reduce the uncertainties regarding the health effects of oxidant air pollution in our childhood population.
DESCRIPTION (provided by applicant): Many chronic lung diseases are caused or exacerbated by environmental factors such as cigarette smoke (chronic obstructive pulmonary disease) and air pollutants including ozone. The lung epithelia provides a first line defense against many of these agents. The cystic fibrosis transmembrane conductance regulator (CFTR) serves a pivotal role in normal epithelial homeostasis, including the maintenance of normal glutathione levels in the epithelial lining fluid (ELF), a critical component of the defense against airborne toxins. In chronic lung conditions, the activation of HIP signaling pathways, such as may be caused by tissue hypoxemia, result in the down-regulation of CFTR mRNA and protein levels (as suggested by studies in cell culture and mice). Reactive oxygen species, such as those produced by ozone exposure in the lung, have been shown to activate HIF signaling pathways. CFTR deficiency results in a significantly decreased level of glutathione in the ELF, predisposing the lung to oxidant/antioxidant imbalance and additional injury from environmental toxins. The repression of CFTR by HIF signaling pathways, activated by both hypoxia and ROS from pollutants like ozone, represents a novel mechanism for lung disease pathogenesis. The goals of this proposal are to investigate 1) the specific effects of ozone on HIF signaling and CFTR expression and function and 2) the molecular mechanisms by which ROS- and hypoxia-induced HIF signaling repress CFTR.
DESCRIPTION (provided by applicant)
The University of Alabama's Center for Labor Education and Research is applying for funding under the NIEHS Hazardous Waste Worker Training Program. The proposed project aims to improve the health and safety of four populations of workers: 1) members of the Communications Workers of America (CWA), 2) Native American tribal members and employees, 3) public safety personnel, and 4) emergency medical service (EMS) personnel and hospital-based first receivers. The program will reduce the likelihood of worker exposures during hazardous material emergency response operations by providing specialized training in topics related to OSHA standard 29 CFR 1910.120. CLEAR will offer courses nationwide to members of CWA-a population of over 700,000 workers in telecommunications, manufacturing, health care, publishing, and law enforcement. Training for Native Americans, a population of 2.4 million, will be offered throughout the U.S. to tribal members and employees including tribal police officers, conservation officers, firefighters, environmental officials, emergency planners, and public works employees. The project will target public safety personnel within the southeastern U.S., a population of 162,990 fire and rescue service and law enforcement personnel. The program will also target a population of 14,865 EMS personnel and hospital-based first receivers-including EMTs and nurses, patient care technicians, and other emergency care providers-in Arkansas, Alabama, Mississippi, and Louisiana. All four target populations have in common the potential for exposures to hazardous materials during emergency incidents, the need for hazardous materials training, and insufficient training budgets. Training will be provided using existing curricula and participatory techniques. Courses to be provided include Hazardous Materials Awareness, Operations, and Technician; Incident Management Systems; Basic and Advanced Air Monitoring; Confined Space Rescue; Respirator Fit Testing; Handling Contaminated Patients; Mass Casualty Incident Triage, Clandestine Drug Lab Awareness; Radiological/Nuclear Awareness; WMD Awareness; and Training Techniques. Peer training will be encouraged and supported through a new computer-based Trainer Support Network. The proposed program will train just under 13,000 trainees, not including computer-based training.
DESCRIPTION (provided by applicant):
It is our goal to develop genomic and proteomic technologies for identification of biomarkers of exposure in girls and rats exposed to bisphenol A (BPA), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and genistein that are measurable in the population. Our specific aims are: 1) to use microarray technology to measure genomic biomarkers of exposure from blood serum and buffy coat, and buccal swabs from (pre)pubertal girls and rats exposed to these chemicals; 2) to develop sensitive and reproducible methods (2D-PAGE and mass spectrometry) to measure protein biomarkers of exposure in blood plasma of (pre)pubertal girls and rats that are expressing high and low levels of these chemicals. An important aspect of this application is not only in the development of new, and use of present state of the art technology for identification of biomarkers of biological responses, but in the experimental design of using a rat model of exposure and a human cohort in similar biological conditions (puberty), also exposed to the same compounds. This unique experimental design will compare the genomic and proteomic changes in a target organ, in this case the rat mammary gland with the presence of peripheral changes in the animals. Whereas in humans we can not detect the changes in the target tissue, the experimented data will give us unbiased information on the target tissue and the peripheral tissue/body fluids that will be important to bioinformatically correlate with the human data. These studies can have a double relevance by first customizing biomarkers identified in a custom array for genes and proteins and second by providing the basis for future assessing these changes for evaluating risk in a larger population. This body of work will be possible because we are utilizing already procured samples from (pre)pubescent girls identified to have high chemical exposures and will have circulating hormone concentrations as indicators of puberty and exposure. From girls (and rats) going through puberty whose urine identifies them as being exposed to high or low concentrations of specific environmental chemicals, we will measure differentially regulated genes and proteins from the blood as biological indicators of chemical exposure. In the rats, we will also measure genes and proteins in the mammary glands as a function of exposure and puberty to gain insight into how environmental chemical exposure early in life predisposes for breast cancer later in life.
DESCRIPTION (provided by applicant):
This Research Center of Excellence (RCE) entitled: "Novel Treatments of Chlorine Induced Injury to the Cardio-Respiratory Systems" consists of three projects and two cores. The unifying theme spanning all projects is that exposure of animals to C12 results in the formation of reactive intermediates which deplete ascorbate and reduced glutathione in the lung epithelial fluids, damage key components of the respiratory and alveolar epithelial [such as transient receptor protein (TRP) and epithelial sodium channels (ENaC)] and then, via inhibition of eNOS signaling compromise seminal functions of the pulmonary and systemic vasculatures. Furthermore, we propose that these toxic effects of C12 will be heightened in animals infected with respiratory syncytial virus or challenged with ova albumin. In our first series of experiments we will perform a number of state of the art biochemical, biophysical, physiological and morphometric measurements in RSV infected and ova albumin challenged mice as well as normal rats prior to and following C12 exposure to document the onset and progression of injury to lung epithelia and pulmonary and systemic vasculature. We will then treat them with antioxidants, TRP antagonists, /32 agonists and nitrite administered at various intervals post C12 exposure either intra-tracheally or via aerosolization or intraperitoneally (antioxidants and nitrite) and quantify recovery by specific functional measurements. Strong points of the RCE include the diverse talents of the investigators, the unique facilities, and the novelty of the preliminary data. The three projects (two of which build on novel findings generated by existing UO1 grants) are supported by an administrative core and the exposure core, which play key roles by both providing essential functions (such as exposure of animals to C12) and helping to integrate the team into a cohesive entity.
DESCRIPTION (provided by applicant): Chlorine (C12) is a moderately soluble, highly reactive oxidant gas, used extensively for water purification, manufacturing of Pharmaceuticals and chemicals and as a potent disinfectant. Persons exposed to chlorine gas, may experience mild symptoms for the first 6-24 hours (h). However, following this latency period, severe lung injury, characterized by protein-rich edema and the onset of hypoxemia may develop. Presently, the cellular and biochemical events leading to this injury have not been elucidated. We propose that reactive oxygen-chloride and nitrogen intermediates (RONS), formed by the interaction of C12 and its hydrolysis products with nitric oxide (NO), initiate self-propagating chain reactions, the products of which damage alveolar epithelial cells decreasing their ability to produce and secrete surfactant, actively transport sodium (Na+) ions and maintain a tight, semi-permeable barrier. Thus, systemic administration of reactive species scavengers (such as ascorbate, N-acetyl-cysteine (NAC), and deferoxamine, as well as agents that augment surfactant levels, ion transport and paracellular resistance (such as albuterol (a long acting b-agonist) and a recently described peptide based on the lectin region of TNFa (tip peptide), shortly after exposure to C12 will decrease lung injury, morbidity and mortality. This hypothesis will be tested by exposing either confluent monolayers of rat alveolar type II (ATII) epithelial cells (SPECIFIC AIM # 1) or rats (SPECIFIC AIMS #2) to C12 (50-200 ppm for 30 min) and measure the following indices at 0.5, 6, 12 and 24 h post exposure: physiological and biochemical indices of lung function (including surfactant function and composition), ability of the lungs to transport ions in vivo and in vitro and clear pulmonary edema in vivo, levels of inflammatory cytokines in the rat alveolar space and in the plasma, arterial blood gases and pH, as well as levels of low reactive species scavengers (ascorbate, NAC) at 0.5, 6, 12, 24 and 48 h post exposure. These measurements will be repeated following intravenous injections of NAC, ascorbate and deferoxamine as well as albuterol and the tip peptide, every 6 h post exposure for 48 h. In SPECIFIC AIM #3 , we will assess the efficacy of intratracheally instilled ascorbate, NAC, deferoxamine, Infasurf (a surfactant replacement mixture), albuterol and the tip peptide, as well as aerosolized albuterol, in prolonging survival of rats with respiratory failure post C12 exposure. The subject matter of this research is both timely and important: more than 25 million tons of chlorine is manufactured annually in the United States and the majority of this gas is transported by rail and can be used as a chemical weapon.
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