Quirks & Quarks

Scientists reverse aging in retinal cells by removing genetic 'rust' to restore vision

The findings suggest that cells retain a memory of their genetically programmed youthful state

The findings suggest that cells retain a memory of their genetically programmed youthful state

Scientists have reversed age-related vision loss in mice. (file photo) (Koichi Kamoshida / Getty Images)

Your eyes may fail you as you get older, but someday it may be possible to reverse that process. According to a new study in the journal Nature, scientists have now shown, in mice at least, that it's possible to reboot retinal nerve cells back to their youthful state.

David Sinclair, a genetics professor at Harvard Medical School, has been investigating the root of aging. He's been focusing on what are known as epigenetic changes which control how genes function in cells.

As we age, we accumulate chemical marks known as DNA methylation, which is somewhat analogous to rust on an old car. These changes interfere with how the DNA works, and cause cells to lose the ability to regulate which genes get made into proteins and when, resulting in the cells not functioning efficiently.

Sinclair said that he found that by delivering a combination of three particular genes to the optical nerve at the back of the eye, he could set in motion a program that cleans off the epigenetic rust and reverses the cellular program for aging.

They investigated by attempting to heal damaged the optical nerves in adult mice, and in older mice with degraded vision due to natural aging, to see how it might impact the nerve that typically doesn't grow back in adults.

Axons regenerate after nerve injury in aged mice given three transcription factor treatment (Yuancheng Lu)

Sinclair told Quirks & Quarks host Bob McDonald that he and his colleagues discovered that after they delivered and turned on the genes for the three transcription factors, the neurons grew back again and restored the rodents' vision.

The findings of this study suggest that not only do optical nerve cells retain a memory of what they were like when they were younger, but that it may be possible to reset the biological clock in other mammalian nerve cells. He's now investigating this further in mice.

Produced and written by Sonya Buyting

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