Computer illustration of amyloid plaques amongst neurons

Neurons (blue) and microglial cells (violet) are interspersed with abnormal deposits (yellow) in this illustration of a brain affected by Alzheimer’s disease. Credit: Juan Gaertner/SPL

Medical research

Stroke drug shows promise for Alzheimer’s disease

Genetically engineered protein prevents brain damage that leads to memory loss.

A drug that is being developed to treat patients after a stroke also protects mice from some of the symptoms of Alzheimer’s disease.

The drug, called 3K3A-APC, is a genetically modified version of a human blood protein that reduces inflammation and also helps prevent neurons and the cells that line the walls of blood vessels from degenerating. Berislav Zlokovic at the University of Southern California in Los Angeles and his colleagues tested whether it could also protect the brain from the toxic effects of the protein amyloid-β, which accumulates in the brain in Alzheimer’s disease. For four months, they performed daily injections of 3K3A-APC in mice that had been genetically altered to be susceptible to amyloid-β accumulation. The drug significantly lowered the brain levels of amyloid-β, and mice that had been treated fared as well as normal mice in memory tests at the end of the treatment period.

The scientists showed that 3K3A-APC prevents brain cells from making an enzyme called BACE1 that is required to produce amyloid-β. In a clinical trial for stroke treatment, the drug proved safe and was well tolerated, and the scientists say it holds potential as a treatment for early-stage Alzheimer’s disease, when amyloid-β levels have not yet accumulated to permanently damaging levels.

Clarification: This article has been updated to clarify that treated mice fared as well as untreated normal mice, not untreated mice susceptible to amyloid-β accumulation.