Researchers hope enzyme will serve as target for multiple sclerosis drugs
February 18, 2004
The Medical Posting
Canadian scientists have identified a new target for the development of drugs to treat and possibly even reverse multiple sclerosis (MS).
"We have identified a key enzyme that triggers MS-like disease in an animal model," says Sam David, a neuroscientist at the Research Institute of the McGill University Health Centre in Montreal. "We also show blocking this enzyme has a remarkable effect in preventing disease and relapses."
An enzyme is a protein that helps biochemical reactions take place in the body. The discovery suggests the enzyme -- called cytosolic phospholipase A2 (cPLA2) -- may be an excellent target for the development of drugs to treat MS, David says.
MS is a chronic disease in which the immune system repeatedly attacks the protective myelin sheath covering nerves in the brain and spinal cord. This can cause vision problems, muscle spasms and weakness. The MS Society of Canada estimates 50,000 Canadians have the disease, which tends to strike between the ages of 20 and 40.
Existing treatments either target inflammation or try to act as a decoy for immune cells. This new discovery approaches the MS problem from within the cell rather than outside it.
David says blocking the enzyme has so far only been shown to help the relapsing/remitting form of the illness, not the progressive, degenerative form.
He also stresses that while cPLA2 influences the progress of MS, it does not cause the disease. In fact, researchers have yet to figure out exactly why the immune system attacks the myelin in the first place.
Nor can David predict how long it will take for researchers to test
inhibitors of the enzyme in clinical trials on humans. "If we rush it,
things can fail and the whole thing gets discredited," he says. "We have
to have time to sit back and think things through properly. ... But my
gut feeling is this should result in treatment for patients down the line."
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