D:        Y’know, Yaël, science has done some amazing things. Could it ever extend our life span, or eliminate aging entirely?

Y:        Nobody really knows, Don. But, a team of researchers from California reported an important breakthrough in 2020. They found a way to reverse aging in several kinds of human cells.

D:        How did they do that?

Y:        They used techniques derived from the ones used to make pluripotent stem cells.

D:        Pluripotent cells are cells that have reverted to their embryonic state. I know that biomedical researchers are interested in them because they can develop into almost any kind of cell in the body. That could come in handy for treating many disorders. But reverting to an embryonic state isn’t really the same thing as reversing aging.

Y:        That’s right. In fact, scientists have found that under certain circumstances pluripotent cells can become cancer cells. Cells are triggered to become pluripotent by a set of proteins called Yamanaka factors. The researchers found that when a cell is triggered to produce the Yamanaka factors for only a short time, the changes in the cell due to aging are reversed, but the cell doesn’t become pluripotent and return to an embryonic state. It doesn’t forget that it’s a specific kind of cell, like a heart cell or a liver cell. Cellular functions were dramatically improved.

D:        So does that mean that the scientists know how to reverse the effects of aging on the human body?

Y:        No it doesn’t. Researchers were able to rejuvenate certain kinds of human cells in a laboratory dish. They are still a long way from learning how to do the same thing in the human body.