MicroRNA as anti-aging molecule in brain

The older we get, our brain ages. Cognitive abilities decline and the risk of developing neurodegenerative diseases like dementia, Alzheimer’s and Parkinson’s disease or having a stroke steadily increases. A possible cause is the accumulation of iron molecules within neurons, which seems to be valid for all vertebrates. In a collaborative research project within the consortium JenAge, researchers from the Leibniz Institute on Aging – Fritz Lipmann Institute (FLI) in Jena, Germany, and the Scuola Normale Superiore (SNS) in Pisa, Italy, found that this iron accumulation is linked to a microRNA called miR-29. This little molecule has so far been known to act as a tumor suppressor, hindering the proliferation of cancer cells. However, clearly, miR-29 also regulates whether or not iron can be deposited in neurons. Using the African fish Nothobranchius furzeri – the shortest-living vertebrate that can be kept under laboratory conditions – the team of Alessandro Cellerino showed a large increase of iron deposits in fish where miR-29 had been suppressed, which led to premature brain aging. In contrast, healthy fish showed the more miR-29 in their neurons, the older they were. Hence, miR-29 acts as a kind of anti-aging molecule during aging, inhibiting the accumulation of iron in neurons.