(Beyond Pesticides, December 6, 2013) In a new study exploring gene-environment interactions, researchers find that individuals with a genetic mutation linked to Parkinson’s disease are more likely to develop the neurodegenerative disease if they are exposed to pesticides. The study, Isogenic Human iPSC Parkinson’s Model Shows Nitrosative Stress-Induced Dysfunction in MEF 2-PGC1Î± Transcription, identifies the molecule that protects neurons from pesticides, ties genetic mutation to pesticide exposure, and demonstrates that low dose exposure can cause Parkinson’s disease.
The study, conducted by researchers at the Massachusetts Institute of Technology and the Sanford-Burnham Medical Research Institute in La Jolla, CA, supports previous epidemiological and animal studies that demonstrate the link between pesticide exposure and neurological damage, using human stem cells as a model.
“For the first time, we have used human stem cells derived from Parkinson’s disease patients to show that a genetic mutation combined with exposure to pesticides creates a ‘double hit’ scenario, producing free radicals in neurons that disable specific molecular pathways that cause nerve-cell death,” says lead author Stuart Lipton, M.D., Ph.D., professor and director at the Sanford-Burnham’s Medical Research Institute.
Using skin cells from Parkinson’s patient who already possess the genetic mutation linked to the disease, researchers transformed them into human induced pluripotent stem cells (hiPSC) and corrected for the mutation in half the cells. Then, researchers transformed these hiPSCs into nerve cells that are damaged by Parkinson’s disease, called A9 dopamine neurons, and control for movement and coordination.
Researchers then exposed these nerve cells to pesticides typical in conventional agricultural areas in the U.S.: “Exposing both normal and mutant neurons to pesticides —including paraquat, maneb, or rotenone— created excessive free radicals in cells with the mutation, causing damage to dopamine-containing neurons that led to cell death,” said coauthor Frank Soldner, M.D., and research scientist.
Notably, researchers also explored the impact of low-doses of pesticides on cells predisposed to Parkinson’s disease. “In fact, we observed the detrimental effects of these pesticides with short exposure to doses well below EPA-accepted levels,” said coauthor Scott Ryan, PhD. and researcher at the Sanford-Burnham’s Medical Research Institute.
The study adds to the increasing body of research surrounding pesticide-induced diseases and raises concerns on how exposures interact with genetic predispositions causing the development of neurodegenerative diseases like Parkinson’s, Alzheimer’s and Amyotrophic lateral Sclerosis (ALS).
Through the Pesticide Induced Diseases Database (PIDD), Beyond Pesticides keeps track of the most recent studies related to pesticide exposure. For more information on the multiple harms pesticides can cause, see our PIDD pages on Alzheimer’s, Parkinson’s, cancer, and other diseases.
Studies such as these highlight the importance of buying, growing, and supporting organic. Consumer choices encourage the protection of the people who help put food on our table every day by purchasing organic. By buying organic, you support an agricultural system that does not permit the application of dangerous pesticides. For more information on how organic is the right choice for both consumers and the farmworkers that grow our food, see Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.