Researchers at the Cedars-Sinai Medical Center have discovered two important defects that occur early in the lives of patients with Parkinson’s disease.
About 6.3 million people worldwide suffer from Parkinson’s disease. Although this degenerative disease mainly affects people aged 60 years and older, it affects adults between the ages of 20 and 50 in 10% of cases. The cause of these Young Adult Parkinson’s Syndromes (PYAS) has so far been poorly understood. Although some cases are associated with known genetic mutations, most are not.
Researchers at the Cedars-Sinai Medical Center seem to have discovered that those diagnosed with Parkinson’s disease before the age of 50 were probably born with a defect in the organization of certain brain cells, which had previously gone unnoticed. Their work has been published in the specialized journal Nature Medicine.
Discovery of 2 important defects that occur at the beginning of life
To carry out this study, the Cedars-Sinai research team recovered so-called induced pluripotent stem cells (iPSc) from cells of patients with Parkinson’s disease at an early stage. This process involves “going back in time” and returning the patient’s adult cells to a primitive embryonic state.
These cells are considered to be one of the greatest advances in biotechnology because they have the ability to differentiate into any cell of the human body. The researchers then used them to produce the so-called dopaminergic neurons (neurons that produce dopamine) of each patient. “This technique gave us a window in time to see how dopaminergic neurons could work early in a patient’s life,” says Clive Svendsen, director of Cedars-Sinai and lead author of the research.
The researchers discovered two major abnormalities that could explain the development of Parkinson’s disease at an early age: the accumulation of a protein called alpha-synuclein in dopamine neurons (a phenomenon observed in most forms of Parkinson’s disease), and defective lysosomes, microcellular organelles that act as “garbage cans” for a cell to decompose and eliminate proteins. This dysfunction can cause an accumulation of alpha-synuclein.
Hope for future patients
“With this new model we have discovered the first signs of Parkinson’s disease at an early stage,” says Clive Svendsen. It seems that the dopaminergic neurons in these individuals may continue to mismanage alpha-synuclein for another 20 or 30 years, leading to symptoms of Parkinson’s disease. These new findings give hope that one day doctors will find a way to regulate the accumulation of alpha-synuclein from an early age.