In accordance with the goals set forth by NIEHS, this project seeks to examine the role of pesticides in the etiology of Parksinon's disease (PD). Numerous reports have suggested a link between the on-set of PD and an agricultural environment, which includes pesticide usage. Patients with PD are also known to have mitochondrial dysfunction. Interestingly, many argochemicals are also known mitochondrial inhibitors. The long-term goal of this project is to understand the relationship of two toxicants, the fungicide maneb and the glyphosate-containing herbicide Roundup, to neuronal toxicity. Using the nematode Caenorhabditis elegans (C. elegans) as a model organism, we will test the hypothesis that exposure to multiple agrochemicals, specifically maneb and Roundup, leads to neuronal degeneration. Additionally, we hypothesize that sequential exposure to these pesticides leads to increased oxidative stress. The hypothesis will be tested through two specific aims: (1) to determine whether exposure to maneb or Roundup affects neuronal populations known to be vulnerable in either PD or manganese neurotoxicity; and (2) to determine whether exposure to maneb or Roundup induces the up-regulation of proteins associated with the production of oxidative stress. In order to complete this study, we will use genetically modified C. elegans with various neuronal populations or antioxidant proteins tagged with green fluorescent protein (GFP). Worms will be exposed to varying concentrations of maneb or Roundup, separately, to determine whether they induce neuronal degeneration or oxidative stress as assessed by fluorescent microscopy. Subsequent studies will examine whether sequential treatment of these two pesticides results in increased toxicity. Results from these novel studies will further our understanding of the neurotoxic effects of multiple pesticide exposures. Additioanlly, they will provide evidence about this ability of these chemicals to induce mitochondrial inhibition in vivo. It is anticipated that data gleaned from these studies will further our understanding not only of pesticide neurotoxicity, but also of the mechanism through which environmental toxicants may facilitate the etiology of idiopathic Parkinson's disease. These studies are particularly important to public health because of the increased use of Roundup, and similar herbicides, by the general public and the agricultural community. Although the main ingredient in Roungup is relatively non-toxic, recent data shows that when the chemical is mixed for commercial usage, the final product may be more toxic. Additionally, this work will examine the effects of exposure to multiple pesticides, which is more likely to occur in human exposures. ? ?
