Protein Helps Neurons Connect, Possibly Reducing Parkinson's Symptoms

Parkinson's Disease

Blocking a protein expressed in dopamine neurons may be able to keep symptoms of Parkinson's disease at bay and even help improve the condition of patients.

In a paper published in the early online edition of the Proceedings of the National Academy of Sciences, a team led by Ole Isacson, Dr. Med. Sc., director of the Neuroregeneration Laboratory and Neuroregeneration Research Center at McLean Hospital, found that a protein called LINGO-1 is able to affect neural connections involving the brain's dopamine system.

"The hope is that LINGO-1 will be one possible example of a way to help the brain maintain its connections," Isacson said. The idea is to find ways to maintain connections between neurons. When such connections are interrupted, brain diseases can take hold.

While LINGO-1 has only been shown to affect Parkinson's, the science being reported in the paper holds promise for fighting other brain diseases as well, Isacson explained. "The science could provide a way to fight against a number of neurodegenerative diseases, including Parkinson's, Alzheimer's, Amyotrophic Lateral Sclerosis and Huntington's," he said.

Parkinson's is a disease characterized by tremors, rigidity, slowness of movement and poor balance. It is a chronic, progressive disease that results when nerve cells in a part of the brain die or are impaired. These nerve cells produce dopamine, an important chemical messenger that transmits signals from one part of the brain to another, according to the National Parkinson Foundation. These signals allow for coordinated movement. When the dopamine-secreting cells die, the other movement control centers in the brain become unregulated.

Isacson's paper notes that new drugs and other therapeutic interventions are needed to simultaneously preserve dopamine neurons and their functional connections to limit or eliminate the progression of the movement disorder.

Other studies have linked the protein LRRK-2 with Parkinson's. Now, this study indicates LINGO-1 may also be linked to the disease. Isacson's study in mice showed that LINGO-1 appears to regulate neuron growth and the structural integrity of neurons, along with LRRK-2. "We found that LINGO-1 is capable of changing the growth of connections in the dopamine system," Isacson said.

The proteins act as growth factors and can cause the connections to either increase or decrease.

Basically, the study found that blocking the function of LINGO-1 works to inhibit the degeneration of dopamine neurons. Isacson said this could be done in a number of ways, including giving antibodies or antagonists that bind to the LINGO-1 protein to block its inhibitory action. "We have started to understand how to maintain connections," Isacson said. "We do not think LINGO-1 is the only way to maintain the structure of the cells, but I think we have shown an important insight. There is also a possible link between LRRK-2 and LINGO-1. They appear to be working together and we are looking at that."