Project description:Toxicogenomic Characterization of Molecular Mechanisms Contributing to Chlorpyrifos Neurotoxicity in Adult Male Rats [smallRNA-seq]
Project description:Chlorpyrifos is an organophosphorus insecticide that despite imposed restricitions on its use by the EPA, is one of the most commonly used insecticides. Although CPF is so widely used little is known about its effect on overall gene expression in vivo. DNA microarray technology was used to determine differential gene expression resulting from chlorpyrifos (CPF) exposure. Keywords: Dose course
Project description:Given the widespread use of insecticides in the environment, it is important to perform studies evaluating their potential effects on humans. Organophosphate insecticides, such as chlorpyrifos, are being phased out; however, the use of pyrethroids in household pest control is increasing. While chlorpyrifos is relatively well studied, much less is known about the potential neurotoxicity of cyfluthrin and other pyrethroids. To gain insights into the neurotoxicity of cyfluthrin, we compared and evaluated the toxicity profiles of chlorpyrifos and cyfluthrin in primary human fetal astrocytes. We found that at the same concentrations, cyfluthrin exerts as great as, or greater toxic effects on the growth, survival, and proper functioning of human astrocytes. By using microarray gene expression profiling, we systematically identified and compared the potential molecular targets of chlorpyrifos and cyfluthrin, at a genome-wide scale. We found that chlorpyrifos and cyfluthrin affect a similar number of transcripts. These targets include molecular chaperones, signal transducers, transcriptional regulators, transporters, and those involved in behavior and development. Further computational and biochemical analyses show that cyfluthrin and chlorpyrifos upregulate certain targets of the interferon-gamma and insulin-signaling pathways and that they increase the protein levels of activated extracellular signal-regulated kinase 1/2, a key component of insulin signaling; interleukin 6, a key inflammatory mediator; and glial fibrillary acidic protein, a marker of inflammatory astrocyte activation. These results suggest that inflammatory activation of astrocytes might be an important mechanism underlying neurotoxicity of both chlorpyrifos and cyfluthrin.
Project description:Given the widespread use of insecticides in the environment, it is important to perform studies evaluating their potential effects on humans. Organophosphate insecticides, such as chlorpyrifos, are being phased out; however, the use of pyrethroids in household pest control is increasing. While chlorpyrifos is relatively well studied, much less is known about the potential neurotoxicity of cyfluthrin and other pyrethroids. To gain insights into the neurotoxicity of cyfluthrin, we compared and evaluated the toxicity profiles of chlorpyrifos and cyfluthrin in primary human fetal astrocytes. We found that at the same concentrations, cyfluthrin exerts as great as, or greater toxic effects on the growth, survival, and proper functioning of human astrocytes. By using microarray gene expression profiling, we systematically identified and compared the potential molecular targets of chlorpyrifos and cyfluthrin, at a genome-wide scale. We found that chlorpyrifos and cyfluthrin targeted a similar number of transcripts. These targets include chaperones, signal transducers, transcriptional regulators, transporters, and those involved in behavior and development. Further computational and biochemical analyses suggest that cyfluthrin and chlorpyrifos up-regulated certain targets of the interferon-gamma and insulin signaling pathways, and that they increased the protein levels of activated ERK1/2, a key component of insulin signaling; IL-6, a key inflammatory mediator; and GFAP, a marker of inflammatory astrocyte activation. These results suggest that inflammatory activation of astrocytes might be an important mechanism underlying neurotoxicity of both chlorpyrifos and cyfluthrin. Keywords: treatment comparison
Project description:Chemical exposures in fish have been linked to loss of olfaction leading to an inability to detect predators and prey and decreased survival. However, the mechanisms underlying olfactory neurotoxicity are not well characterized, especially in environmental exposures which involve chemical mixtures. We used zebrafish to characterize olfactory transcriptional responses by two model olfactory inhibitors, the pesticide chlorpyrifos (CPF) and mixtures of CPF with the neurotoxic metal copper (Cu). 30 one-year-old adult AB strain zebrafish were exposed, in groups of three, to CPF/Cu concentrations of 0/0, 0.1/0, 0.25/0, 0.6/0, 0/0.1, 0/0.25, 0/0.6, 0.1/0.25, 0.25/0.25, 0.6/0.25.
Project description:Extrauterine growth restriction on pulmonary vascular endothelial dysfunction in adult male rats: the role of epigenetic mechanisms
Project description:Chlorpyrifos (CPF) is an organophosphorus pesticide (OP), and one of the most widely used pesticides in the world. Metabolites of CPF and other OPs continue to be identified in the majority of human samples, even in countries such as the United States where OP use is declining (Arcury et al., 2010). The effects of repeated occupational and environmental exposures to OPs are poorly understood, although human and animal studies consistently identify neurotoxicity as the primary endpoint of concern. Thus, occupational exposures to sublethal doses of CPF are consistently associated with problems in cognitive abilities, such as learning and memory but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of CPF neurotoxicity, we employed a rat model that simulated documented CPF exposures in Egyptian agricultural workers. We quantified mRNA expression profiles in the CA1 region of the hippocampus of adult male Long Evans (LE) rats administered CPF at 3 or 10 mg/kg/d (s.c.) for 21 days. Despite significant inhibition of cholinesterase activity by the end of the 21 d exposure period, the CPF-exposed rats displayed minimal signs of cholinergic toxicity. Distinct hippocampal mRNA and miRNA signatures were associated with CPF exposure. Toxicogenomics-based evidence identified increased expression of neuropeptide genes in the hippocampi of CPF-exposed rats, which have been shown to activate receptor-mediated signaling pathways involved in cell survival. The analysis of small non-coding RNA profiles suggested the possibility that miR132/212-mediated homeostatic regulatory pathways may also be activated by repeated exposures to CPF. These findings identify potential molecular effects that may contribute to neurobehavioral deficits.