May 11, 2009
MIT researchers who were previously able to reverse the signs of Alzheimer's disease in mice have now identified the specific gene involved in the process.
The gene, called HDAC2, is part of a family of genes known to regulate gene expression by modifying a structure in the cell nucleus called chromatin. When HDAC is inhibited, this structure is loosened up, effectively letting other important genes express themselves.When the researchers gave HDAC2 inhibiting drugs to mice who were bred to have a condition similar to Alzheimer's disease in humans, the mice regained the ability to perform previously learned, but forgotten, tasks and, what's more, were able to learn new tasks. Other mice that were bred to produce no HDAC2 all exhibited enhanced memories.
Given the ability of HDAC2 inhibitors to reverse the symptoms of Alzhemier's disease in mice, the researchers speculate memories that seem to be lost in people with the condition aren't really "lost" at all "“ they have just become inaccessible due to the effects of HDAC2.
"These findings are in line with a phenomenon known as "Ëfluctuating memories,' in which demented patients experience temporary periods of apparent clarity," study author Li-Huei Tsai was quoted as saying.
Now she and her colleagues plan to see whether the drugs used in mice might be successful in people as well. "In the next step, we will develop new HDAC2-selective inhibitors and test their function for human diseases associated with memory impairment to treat neurodegenerative diseases."
Other HDAC inhibiting drugs are already being testing in Huntington's disease and as anticancer agents.
SOURCE: Nature, published online May 6, 2009