Ronald DePinho reverses aging in mice
Scientists have reversed the signs of aging in mice, according to a study published in the journal Nature. We spoke with the study’s lead scientist, Ronald DePinho, of the Dana-Farber Cancer Institute in Boston.
The most important lesson that we learned from this study is that aged tissues, even ones in an advanced state of degeneration, retain a remarkable capacity to renew themselves.
What the scientists did was engineer mice with a gene that can be switched on and off. The gene controls an enzyme that builds special cell structures – called telomeres -that cap the end of our chromosomes, the stuff in cells that pass on genetic traits. Dr. DePinho explained:
As we age, we incur damage at the telomeres, as well as the telomeres become eroded. And over the course of time, that signals to the cell to enter an aged state.
The mice DePinho studied were artificially aged by switching off the enzyme. When the enzyme was switched off, their organs withered. They got grey hair, dermatitis, and became infertile, said DePinho. When the enzyme was switched back on, they became younger.
We were expecting maybe a slowing or a stabilization of the aging process. Instead, we witnessed a dramatic reversal in the signs and symptoms of aging. The brains increased in size, cognition improved, the coat hair was restored to a healthy sheen, and fertility was restored.
So this teaches us that there is a point of return for these tissues if you remove the underlying cause, which in this case was excessive DNA damage at the tips of our chromosomes.
Dr. DePinho emphasized that this is no “fountain of youth.” He said that there are multiple factors that conspire to affect the aging process.Much more research is needed before scientists understand how to turn back the clock on aging.
Dr. DePinho described the status of his research.
There are so many facets to this story that’s just a rich fabric, a rich opportunity for us to explore further, the molecular underpinnings of the aging process. I’d say first and foremost, we want to understand how is it that these very aged tissues retained this capacity to almost completely rejuvenate themselves. What are the cellular and molecular mechanisms that underlie that process, and can that illuminate a path towards clinical intervention somewhere down the road.