Recent findings shed new light on the interplay of genetics and the immune system in Parkinson’s disease. In the study, gut infections appear to trigger a reaction that leads to Parkinson’s.
The study, published in Nature, was led by Dr. Michel Desjardins and Louis-Eric Trudeau from the University of Montreal, Dr. Heidi McBride at the Montreal Neurological Institute, and Dr. Samantha Gruenheid at McGill University. The team, which received funding from The Michael J. Fox Foundation for an early part of this study, was investigating a known paradox in Parkinson’s research. While nearly 100 percent of people with mutations in PINK1 and PRKN genes develop Parkinson’s, mice with these mutations exhibit no symptoms of the disease. The researchers hypothesized that the issue may be related to differing environments: the mice live in sterile, germ-free facilities while humans are exposed to infections and toxins in our daily lives.
To test this, the researchers exposed young mice with PINK1 and PRKN mutations to mild intestinal infections, which are common in people. Later in life, the mice all went on to develop symptoms of Parkinson’s disease. Healthy mice – without these genetic mutations – have no problem fighting off the infection and did not go on to develop Parkinson’s.
Dr. Desjardins explains that in mice with these genetic mutations, the immune system overreacts with an auto-immune response, resulting in the immune system attacking brain cells. The authors also note the results suggest that, “some forms of Parkinson’s disease are an autoimmune disease likely to start in the gut several years before patients notice any motor symptoms, highlighting the fact that a window of time exists for preventive treatment.”
While these findings point to new avenues for treatment, researchers need to replicate the results in people. Previous studies indicate the PINK1 and PRKN are involved in the function of mitochondria, the energy centers of our cells. Additional research is needed to better understand their interaction with our immune system.
Article Source: The Michael J. Fox Foundation