Cholesterol Plays a Role in Alzheimer’s

A protein, called beta amyloid, builds up in the brains of people with Alzheimer’s disease (AD). Cholesterol may be a factor in how much beta amyloid is produced.

A recent study found that the production of beta amyloid requires cholesterol to bind to the protein.

This helps to explain why cholesterol has been linked to AD in the past, and this finding may give researchers new treatment ideas.

Talk to your doctor about treatment options for Alzheimer's.

The study, led by Paul J. Barret, a graduate student, with Charles R. Sanders, PhD, of the Vanderbilt University School of Medicine, looked at brain proteins to see how cholesterol might interact with them.

Beta amyloid is a complex protein made in the body. It takes three different steps to become beta amyloid. First, it starts as the amyloid precursor protein. An enzyme changes it into a protein named C99. Then C99 is changed again by another enzyme to become beta amyloid.

The researchers used nuclear magnetic resonance and electron paramagnetic resonance spectroscopy, both methods for looking at microscopic structures, to look at the structure and binding properties of C99.

They found that C99 had a cholesterol binding site -  an area on the molecule that is set up to attach to cholesterol. They also found that when cholesterol was not bound to C99, it was changed by a different enzyme and did not become beta amyloid.

The authors conclude that C99 binding with cholesterol may explain the previously reported relationship between cholesterol and AD.

Targeting the relationship between cholesterol and C99 could lead to new treatments for the disease, said the authors. 

No treatments for AD were investigated by this study. The research report was published June 1 in Science. No conflicts of interest were disclosed.