Reprogramming rejuvenates nerve cells and restores vision in mice

For years now, biologists have been practicing a kind of time travel. You can take a patch of human skin and, with the right genetic adjustment, set back its internal clock until it becomes its embryonic self, stripped of its identity and ready to become just about any part of it. human body. Since the method was published in 2006, the transformation of adult cells into stem cells has allowed all kinds of progress. Researchers can grow organs in dishes. They can mimic what happens in the uterus without the regulatory headache of acquiring fetal tissue. It has become an everyday tool on laboratory benches around the world and has won a Nobel Prize.

But for David Sinclair’s needs, that wasn’t enough. His interest was in reversing the slings and arrows of old age, using this genetic time machine to create something that would actually be therapeutic. When the cells were rewound to an embryo-like state, they did what embryonic cells do: divide like crazy. Apart from the complex control of the prenatal environment, which gave rise to cancer. The mice used in such experiments died within days. “We wanted to bring the age of a tissue back, but find a way to keep it from going too far back,” said Sinclair, professor of genetics at Harvard Medical School.