WIKIMEDIA, SHWSIEResearchers at the Salk Institute for Biological Studies in San Diego have extended the lives of some mice while promoting organ and muscle recovery in others, according to a study published last week (December 15) in Cell. The scientists accomplished the feat by activating four genes known as “Yamanaka factors,” a combination of transcription factors discovered in 2006 that can convert differentiated cells into pluripotent precursors. The study was limited in scope, but it has created a stir among scientists hoping to slow the effects of aging and treat rare, aging-related diseases.
“Our study shows that aging may not have to proceed in one single direction,” coauthor Carlos Izpisua Belmonte of the Salk Institute told The Guardian. “With careful modulation, aging might be reversed.”
Indeed, careful modulation appears to be key. Early attempts to reverse aging with high doses of the Yamanaka factors led some of the mice to develop tumors and die within a week. “We’ve all been playing with fire,” David Sinclair, a Harvard University anti-aging researcher who was not involved in the study, told Scientific American. “This is going to be what we spend the next 10 years figuring out—how to reprogram cells to be young again without taking it too far so they become tumors.”
One group of mice was genetically engineered to model progeria, a rare genetic disorder that causes rapid aging and premature death in both humans and mice. The right balance of Yamanaka factors appeared to extend the lives of these animals by 30 percent, on average, even though they retained the progeria mutation. Another group of healthy, older mice treated with the Yamanaka factors regained the ability to regenerate muscle cells, a quality typically lost in old age, the researchers reported.
The findings have yet to be independently replicated and, the team noted, have no immediate implications for human aging. But the results broadly suggest that aging is in part related to epigenetic changes, Sinclair told Scientific American. “I do think that epigenetic reprogramming is the ultimate way to reverse aging,” he said.