Grant: $230,750 - National Institutes of Health - Jul. 16, 2009
No votes have been cast for this award yet
Award Description: Our long term goal is to study the mechanism of neurodegeneration induced by environmental neurotoxicants. This proposal is submitted to investigate gene-environment interactions in the pathogenesis of Parkinson's disease mediated through the mitochondrial pathway. Mitochondrial dysfunction has been proposed as a major mechanism of neurodegeneration in PD for years, but direct evidence in humans was inadequate until the recent discoveries of mutations in PTEN-induced putative kinase 1 (PINK1), which encodes a mitochondrial kinase. Although PINK1 mutations are associated with autosomal recessive PD, interestingly, an increasing number of PD patients carrying single heterozygous mutations have been reported. These observations suggest that a heterozygous PINK1 mutation may act as a susceptibility factor that interplays with environmental insults. To determine the interactions between PINK1 mutations and environmental toxicants, we have created stable cell lines with inducible over-expression of various PINK1 mutants. Based on our preliminary results, we hypothesize that PINK1 mutations increase cell susceptibility to environmental toxicants such as paraquat (PQ) through a novel mechanism: mitochondrial fragmentation via the mitochondrial fission / fusion machinery. In the first specific aim, we will characterize neurotoxicity induced by PQ and MPP+ (two toxicants representing different mechanisms of toxicity) through the mitochondrial fission and fusion pathway in N27 cells with a PINK1 mutation (L347P) and empty vector control, as well as in N27 cells with PINK1 knockdown mediated by siRNA. We will assess cell viability, functional outcomes (ATP production, dopamine release and electron transport chain activity), as well as mitochondrial fragmentation (size/shape) and alterations in mitochondrial fission and fusion proteins. In specific aim 2, we will perform neuroprotective experiments against PQ and MPP+ toxicity in mutant PINK1 cells by targeting the mitochondrial fission and fusion pathway, through genetic manipulations and a small molecule. We will transfect cells with relevant constructs and use a chemical inhibitor to attenuate mitochondrial fragmentation. The neuroprotective effects of these two strategies against MPP+ and PQ toxicity will be determined using cell viability and functional assays as described in specific aim 1.
Project Description: The major goal of this study is to investigate the interactions between PINK1 mutations and environmental toxicants such as pesticides. Our preliminary results indicate that although genetic mutation in PINK1 alone is insufficient to cause neuronal death, it increase cell susceptibility to environmental toxicants. Furthermore, we expect that through genetic or pharmacological approach, we can reduce cell death through the mechanism proposed in this grant.
Jobs Summary: The University of Rochester created/retained an Associate Professor and Assistant Professor. (Total jobs reported: 0)
Project Status: Less Than 50% Completed
This award's data was last updated on Jul. 16, 2009. Help expand these official descriptions using the wiki below.