High cholesterol in brain linked to Huntington's disease

Huntington's disease is linked to an abnormal build-up of cholesterol in the brain, and an interaction between proteins may explain how, researchers say.

Huntington's disease is a progressive condition that causes nerve cells in the brain to waste away, leading to symptoms such as uncontrolled movements, emotional disturbances and difficulty recalling recent events or making decisions.

There are no treatments to stop or slow down the disease, although some drugs may reduce the symptoms. People with Huntington's often die of complicationsfrom falls or from infections.

The new research focuses on how a protein interaction causes cholesterol — which is needed to promote connections between brain cells and keep their membranes intact —to accumulate in the brain.

"Our discovery that the mutant Huntington's disease protein derails the cholesterol delivery system and causes cholesterol accumulation in neurons provides us with key results and solid clues to the mechanism of this disease," said study author Cynthia McMurray, a molecular biologist at the Mayo Clinic in Rochester, Minn.

"Fully understanding the mechanism of toxicity is the key to developing treatments."

McMurray's team found that a mutated protein in Huntington's attacks the transportation system between brain cells, which prevents the delivery of materials the neurons need to work properly.

The findings are reported in the December issue of the journal Human Molecular Genetics.

About one in every 10,000 Canadians has Huntington disease, and about five in 10,000 are at risk of developing the hereditary disease, according to the Huntington Society of Canada.