New protein points to possible Alzheimer’s cure

An 84-year old American Nobel Laureate has discovered a new protein which observers are saying is one of the most significant breakthroughs yet in the hunt for a cure for Alzheimer’s disease.

Most current drugs for treating Alzheimer’s are aimed suppressing the ability of an enzyme called gamma secretase to produce a protein called beta amyloid. Beta amyloid exists in all healthy brains, however an over abundance of its is linked with a build up of plaque on the brain, a key indicator of Alzheimer’s.

The problem is that gamma secretase performs all manner of important tasks in the human body, including the production of other important proteins. As was demonstrated last month by the high profile failure of Eli Lilly’s new experimental Alzheimer’s drug, completely blocking it can in fact make the disease worse.

A scientist at New York’s Rockefeller University, Paul Greengard received a Nobel Prize for medicine in 2000 for his work on signalling in brain cells.

In a paper published this week in Nature, he shows that before gamma secretase gets going, a protein which he calls gamma secretase activating protein, first tells the enzyme to make beta amyloid. Blocking it therefore effects only the production of beta amyloid, with other gamma secretase activities left to go about their business.

Interestingly, Greengard and his team found that a cancer drug called Gleevec, currently on the market to treat certain forms of leukaemia as well as a rare cancer of the digestive system, blocks this newly discovered protein.

Gleevec itself is unsuitable for treating Alzheimer’s because it is pumped out of the brain as quickly as it is pumped in, however researchers note that it should be possible to engineer similar compounds which remain in the brain.

Greengard’s work is funded by a philanthropic organisation formed soley to support his work.

This latest paper is being viewed as one of the most important ever to emerge in the crowded field of Alzheimer’s research, which currently produces no less than 1000 papers a month.