A drug that is approved for the treatment of a type of skin cancer since 1999 has shown to reverse Alzheimer’s symptoms in lab mice.
Case Western Reserve University School of Medicine neuroscientist Gary Landreth and colleagues reported Thursday that the drug Bexarotene quickly cleared away beta-amyloid plaque, believed to cause the cognitive deficits of Alzheimer’s disease, from the brains of genetically engineered mice.
They found that mice who received Bexarotene treatment regained memory and cognitive function, including improvements in their sense of smell. The Alzheimer’s-afflicted mice were able to resume normal behaviors, such as shredding paper for nest building, three days after treatment. Bexarotene worked by helping to increase levels of a protein called Apolipoprotein E (ApoE), which helps remove beta-amyloids. Its effects took hold quickly, with half of plaques removed within 72 hours, the authors reported.
Paige Cramer, a Ph.D. candidate at Case Western Reserve, said in a statement that the research had produced “an unprecedented finding”, noting that the previous best treatment for Alzheimer’s in mice took several months to reduce plaque. “As a consequence of aging, the ability to clear plaque from the brain goes down, and we are able to enhance ApoE”, Cramer said. “The benefit of this drug is we are just facilitating or enhancing Mother Nature.” The study appeared online in the journal Science.
Scientists warn that it would take six years or longer before bexarotene might be used to treat people with the degenerativebrain disease. “Ultimately, you have to test this in humans”, said Dr. Lon S. Schneider, an Alzheimer’s researcher at USC’s Keck School of Medicine in Los Angeles.
Dr. William Klunk, co-director of the Alzheimer’s Disease Research Center at the University of Pittsburgh, said the current study on Bexarotene opens an exciting new avenue for the potential successful treatment of the disease. But he remains cautiously optimistic. “We in this field have seen enough success in mouse studies not pan out in human studies to know this is just the beginning and there’s a long way to go”, Klunk said.