Scientists Discover Drug Candidate for Alzheimer’s, Huntington’s

Scientists at the Gladstone Institutes have identified a drug candidate that diminishes the effects of both Alzheimer's disease and Huntington's disease in animal models, offering new hope for patients who currently lack any medications to halt the progression of these two debilitating illnesses.

Gladstone Investigator Paul Muchowski, PhD, has identified a new compound called JM6 in experiments done in collaboration with an international team of researchers, and which are being published today in an online article in Cell. In laboratory tests involving mice genetically engineered to model one or the other of the two diseases, Dr. Muchowski's team found that JM6 blocks kynurenine 3-monooxygenase (KMO), an enzyme that has long been speculated to play a role in neurodegenerative diseases.

In mice modeling Alzheimer's disease, the novel compound prevented memory deficits and the loss of synaptic connections between brain cells—both of which are key features of the human disease. In mice modeling Huntington's disease, JM6 prevented brain inflammation and the loss of synaptic connections between brain cells, while also extending lifespan.

“This discovery has significant implications for two devastating diseases and suggests that the KMO enzyme is a good protein for us to target with medications in diverse neurodegenerative disorders,” said Lennart Mucke, MD, who oversees all neurological research at Gladstone and who won the prestigious Potamkin Prize last year for developing experimental strategies to make the brain more resistant to Alzheimer's. “With any luck, Dr. Muchowski and his colleagues could begin testing this drug in patients within the next two years.”

Remarkably, JM6 (see structure) does not penetrate into the brain, but works by inhibiting KMO in the blood. The blood cells then send a protective signal to the brain, to stabilize brain-cell function and prevent neurodegeneration. The fact that the compound does not pass the so-called blood-brain barrier will facilitate testing in patients, as JM6's potential impact could be confirmed with a simple blood test.

JM6 was named for Dr. Muchowski's father, Dr. Joseph Muchowski, PhD, a retired medicinal chemist who helped his son devise the novel KMO inhibitor. The study was carried out in collaboration with the laboratories of Dr. Robert Schwarcz, a University of Maryland School of Medicine professor who pioneered studies linking KMO and metabolically related enzymes to nerve-cell loss, and Professor Eliezer Masliah at the University of California, San Diego, an expert in neuropathology.

 Ref : www.cell.com/abstract/S0092-8674(11)00581-2

Combination of EGCG & DAPH-12 - a treatment for brain disorders ?

Amyloid plaques are tightly packed sheets of proteins that infiltrate the brain. These plaques, which are stable and seemingly impenetrable, fill nerve cells or wrap around brain tissues and eventually (as in the case of Alzheimer's) suffocate vital neurons or brain cells, causing loss of memory, language, motor function and eventually premature death.

To date, researchers have had no success in destroying plaques in the human brain and only minimal success in the laboratory. One reason for these difficulties in finding compounds that can dissolve amyloids is their immense stability and their complex composition.

Yet, Dr. Duennwald ( Boston Biomedical Research Institute , BBRI) and co workers from Pennsylvania School of Medicine, experienced success in previous studies when he exposed amyloids in living yeast cells to EGCG (see the above structure). Furthermore, he and his collaborators also found before that DAPH-12, (see below structure) too, inhibits amyloid production in yeast.

About EGCG :

Epigallocatechin gallate, also known as Epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid and a type of catechin. EGCG is the most abundant catechin in most notably tea, among other plants, and is also a potent antioxidant and that may have therapeutic properties for many disorders including cancer. It is found in green tea, but not black tea, as EGCG is converted into thearubigins in black teas. EGCG can be found in many supplements.

These findings are significant because it is the first time a combination of specific chemicals (EGCG & DAPH-12) has successfully destroyed diverse forms of amyloids at the same time.

Though the detailed mechanism is still to be established, its a good achievement and hope this combinatorial therapy will help those sufferings from Alzheimer's and other degenerative diseases (Huntington's, and Parkinson's) in the days to come.....

Ref : http://www.nature.com/nchembio/journal/v5/n12/pdf/nchembio.246.pdf