Pathologist Keqiang Ye has made a series of discoveries recently, arising from his investigations of substances that can mimic the growth factor BDNF (brain-derived neurotrophic factor).
BDNF is a protein produced by the brain that pushes neurons to withstand stress and make new connections. Some neuroscientists have described BDNF as “Miracle Gro for brain cells.”
â€œBDNF has been studied extensively for its ability to protect neurons vulnerable to degeneration in several diseases, such as ALS, Parkinsonâ€™s and Alzheimerâ€™s disease,â€ Ye says. â€œThe trouble with BDNF is one of delivery. Itâ€™s a protein, so it canâ€™t cross the blood-brain barrier and degrades quickly.â€
Working with Ye, postdoctoral fellow Sung-Wuk Jang identified a compound called 7,8-dihydroxyflavone that can duplicate BDNFâ€™s effects on neurons and can protect them against damage in animal models of seizure, stroke and Parkinsonâ€™s disease. The compoundâ€™s selective effects suggest that it could be the founder of a new class of brain-protecting drugs. The results were published in Proceedings of the National Academy of Sciences.
7,8-dihydroxyflavone is a member of a family of antioxidant compounds naturally found in foods ranging from cherries to soybeans. Ye says his laboratory has already identified compounds that are several times more active. The next step is more animal studies to choose compounds likely to have the best drug profiles: stable and non-toxic.
â€œIt is likely that many people take in small amounts of 7,8-dihydroxyflavone in their diets,â€ he says. â€œBut drinking green tea or eating apples doesnâ€™t give you enough for a sustained effect.â€
Along the way to finding 7,8-dihydroxyflavone, Jang and Ye have also identified other molecules, both natural and artificial, which can mimic BDNF. For example, the tricyclic antidepressant amitryptiline activates the same signaling molecules as BDNF in neurons. In addition, a precursor of melatonin, the hormone that regulates sleep/wake rhythms, has similar properties, although melatonin itself does not. These results provide an alternative mechanism for how some antidepressants may exert their effects, Ye says.
An article from neuroscientist Kerry Resslerâ€™s laboratory describing how 7,8-dihydroxyflavone and genetic manipulation of BDNF can be used to probe fear memory formation was also recently published in PNAS.