The peptide blocks a hyperactive brain enzyme that contributes to the neurodegeneration seen in Alzheimer’s and other diseases.

MIT neuroscientists have found a way to reverse neurodegeneration and other symptoms of Alzheimer’s disease by interfering with an enzyme that is typically overactive in the brains of Alzheimer’s patients.

When the researchers treated mice with a peptide that blocks the hyperactive version of an enzyme called CDK5, they found dramatic reductions in neurodegeneration and DNA damage in the brain. These mice also showed improvements in their ability to perform tasks such as learning to navigate a water maze.

“We found that the effect of this peptide is just remarkable,” says Li-Huei Tsai, director of MIT’s Picower Institute for Learning and Memory and the senior author of the study. “We saw wonderful effects in terms of reducing neurodegeneration and neuroinflammatory responses, and even rescuing behavior deficits.”

With further testing, the researchers hope that the peptide could eventually be used as a treatment for patients with Alzheimer’s disease and other forms of dementia that have CDK5 overactivation. The peptide does not interfere with CDK1, an essential enzyme that is structurally similar to CDK5, and it is similar in size to other peptide drugs that are used in clinical applications.

Picower Institute Research Scientist Ping-Chieh Pao is the lead author of the paper, which appears this week in the Proceedings of the National Academy of Sciences.