Parkinson's may take two forms, one more toxic than the other

Researchers have identified two different forms of Parkinson's disease--one that is more toxic than the other--which may explain why symptoms of the neurodegenerative disorder can vary greatly from one patient to another.

The hallmark of Parkinson's disease is a buildup of the protein alpha-synuclein, which forms aggregates within dopamine-creating neurons, eventually killing them. Dopamine is a neurotransmitter essential to many brain functions. A consortium of scientists headed by a team at the French National Centre for Scientific Research has found that two different types of alpha-synuclein aggregates exist--one of which is better at invading neurons, making it more toxic.

The findings, which could eventually lead to advances in Parkinson's treatment--including the development of targeted therapies to treat both forms of the disease--were published Oct. 10 in Nature Communications.

In the lab, researchers replicated two types of aggregate, which differ in how the protein stacks up. The first form of aggregate looks like spaghetti, whereas the second form is long and flat, resembling wider pasta such as linguine.

To test whether these structural differences contribute to functional differences, researchers placed the two types of aggregates in contact with neuronal cells in culture. Not only was the "spaghetti" form able to bind to and penetrate cells better than the "linguine" form, but the former type also killed infected cells faster. The scientists are now running similar tests on mice.

In addition to helping find novel, targeted therapies, the researchers believe that the type of aggregate could be used as a new way to diagnose Parkinson's, making it possible to assess the virulence of the disease for each patient.

- read the study in Nature Communications
- check out the press release