Scientists at the Salk Institute in La Jolla announced Thursday they have been able reverse aging in laboratory mice and increase their lifespans by 30 percent.
“Our study shows that aging may not have to proceed in one single direction,” said Juan Carlos Izpisua Belmonte, a professor in Salk’s Gene Expression Laboratory and senior author of the paper published in the journal Cell. “It has plasticity and, with careful modulation, aging might be reversed.”
The scientists used cellular reprogramming techniques to rejuvenate mice with premature aging disease, countering signs of aging, and also were able to make human skin cells in a dish to look and behave young again,
The early-stage work provides insight into both the cellular drivers of aging and possible therapeutic approaches for improving human health and longevity.
Cellular reprogramming is a process in which the expression of four genes known as the Yamanaka factors allows scientists to convert any cell into induced pluripotent stem cells, which are capable of dividing indefinitely and becoming any type of cell.
“What we and other stem-cell labs have observed is that when you induce cellular reprogramming, cells look younger,” said Alejandro Ocampo, a research associate and first author of the paper. “The next question was whether we could induce this rejuvenation process in a live animal.”
While cellular rejuvenation sounds desirable, a process that works for laboratory cells is not necessarily a good idea for an entire organism. For one thing, although rapid cell division is critical in growing embryos, in adults such growth is one of the hallmarks of cancer. For another, having large numbers of cells revert back to embryonic status in an adult could result in organ failure.
So the Salk scientists induced reprogramming but for only short durations in live mice with premature aging disease. Compared to untreated mice, the reprogrammed mice looked younger, their cardiovascular and other organ function improved, and they lived 30 percent longer, yet did not develop cancer.
“Obviously, mice are not humans and we know it will be much more complex to rejuvenate a person,” said Izpisua Belmonte. “But this study shows that aging is a very dynamic and plastic process, and therefore will be more amenable to therapeutic interventions than what we previously thought.”
