Cell-free DNA Methylation Patterns and Mitochondrial Therapeutics in a Rodent Model of Organophosphate Poisoning

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

The overarching goal of this proposal is to further delineate the mitochondrial involvement in acute and chronic poisoning from organophosphates (OP). We will investigate the mitochondrial contribution to neurological, cardiac and microcirculation sequela with a focus on novel biomarker development and therapy. An estimated 385 million cases of acute unintentional pesticide poisoning occur worldwide each year, resulting in around over 300,000 fatalities from OPs alone. Sources of OP exposure occur in farming communities, occupational settings and as agents of threats. The primary mechanism of action is increased cholinergic activation leading to excessive muscarinic symptoms such as respiratory distress and seizures. In addition, chronic OP exposure can lead to long-term neurologic and cardiac sequelae such as motor dysfunction and heart failure. While the effects of OPs on the autonomic nervous system (acetylcholine) is thought to be the primary mechanism of injury, our group has mapped out significant mitochondrial involvement at Complex I. Survivors of acute poisoning and those with chronic exposure demonstrate long-term sequela often without any overt cholinergic symptoms. Significant knowledge gaps include: (1) the degree of mitochondrial injury contributing to long-term sequelae; (2) lack of tissue-specific biomarkers to gauge severity of disease and guide therapy; (3) lack of complementary treatment strategies to mitigate cardiac and neurologic disability. This project will further delineate the mitochondrial pathways involved in OP poisoning using extracellular cell-free DNA (cfDNA) as a biomarker in a rodent model of OP poisoning, furthering the mechanistic understanding of OP poisoning and developing cfDNA as potential biomarker and tissue source using DNA methylation patterns. CfDNA is an established prognostic indicator for mortality in an array of disease states. CfDNA is released into circulation upon injury and have been used as a marker of disease severity. We also propose to investigate a select mitochondrial-based therapeutic in vivo to improve mitochondrial respiration, sustain cellular function, and limit organ injury circumventing the known Complex I effect seen in our supporting publications and preliminary data.