While investigating the role of rapamycin (an FDA-approved immune-suppressant drug) in aging of yeast, fruit flies and C. elegans, researchers in Matt Kaeberlein’s lab also discovered something else. The drug can extend lifespan and alleviate neurological symptoms in a mouse model of mitochondrial disease.
Mitochondria are a cells’ power generators, and mitochondrial dysfunction can lead to severe pathology in humans, including neurological and muscular degeneration, cardiomyopathies, cancer, diabetes, and pathologies of aging. Severe mitochondrial defects can result in childhood disorders such as Leigh syndrome, for which there are no effective therapies.
A study published in Science, mTOR inhibition alleviates mitochondrial disease in a mouse model of Leigh syndrome describes the findings—that mice treated with rapamycin for mitochondrial disease lived two or three times longer than untreated ones. “About half the mice showed no behavioral or molecular signs of the disease when they finally died,” Kaeberlein says.
Kaeberlein is excited — for the potential that this work may have in benefiting children affected by Leigh syndrome and for further aging-related studies. “Severe mitochondrial diseases are not obviously related to aging, so this finding is taking us in directions we did not expect to go,” he says.
Pictured Above: Leigh syndrome mouse on the left shows the hair loss and short stature characteristic of the disorder. For comparison is a normal mouse on the right. Photo by Melana Yanos.