Crossing Blood-Brain Barrier: New Hope for New Class of Alzheimer's Disease Drugs

Alzheimer's disease is the seventh leading cause of death and affects millions of people in the U.S. alone, but researchers believe that they have made a breakthrough in the hope of creating a drug that helps patients cope with Alzheimer’s.

The main problem when creating drugs to help patients with Alzheimer’s disease (and other neurological diseases) is finding a chemical able to cross the blood-brain barrier, which are tight junctions in the brain capillaries that prevent free exchange of many substances between the blood and the cerebrospinal fluid. In a healthy brain, the microtubules in nerve cells are stabilized by protein tau, and serve the important function of transporting cellular material. In a brain affected by Alzheimer’s disease, protein tau clumps in the brain due to it becoming insoluble. When this happens, regular protein tau is reduced, and the microtubules become less stable.

Researchers have been using microtubule stabilizing drugs to offset tangles of tau and balance the loss of normal tau function, and have recently discovered a class of drugs that can enter the blood-brain barrier to stabilize the degrading neurons and also improve learning and memory. Years ago, it was shown that the anti-cancer drug paclitaxel advanced spinal cord function in animals with protein tau tangles in their brain, but it could not cross the blood-brain barrier. Now researchers are looking into the epothilone class of agents, especially epothilone D, to stabilize microtubules. The epothilone class of drugs are microtubule binding drugs that come from marine sponges and keep cells from dividing by over stabilizing the microtubules. When researchers gave mice epothilone D, the brain function of the mice improved, even though the mice had tau clumps, broken down microtubules, and deteriorated axons. Epo D also reduced memory and learning deficit in the mice. These results show that epo D, and microtubule stabilizing drugs in general, could be breakthrough ways to treat neurodegenerative diseases in humans.

I was interested in this article because it deals with neurophysiology and treatments of neurodegenerative diseases, which we recently discussed in class, and I was fascinated by it. I also found it interesting how they are treating this disease and the progress they have made.

http://www.sciencedaily.com/releases/2010/10/101018151256.htm