As a  postdoctoral student, Matt Kaeberlein, PhD was searching for genes that affected lifespan and by luck and accident discovered that lifespan could be extended by suppressing the gene mTOR.The gene exists in every organism except bacteria.  Between 2004 and 2006 several researchers published studies that showed that inhibiting mTOR in various animals increased their lifespan and slowed aging. Dr. Kaeberlein was one of the first scientists to research the role of rapamycin as an effective inhibitor of mTOR.

Rapamycin is a small molecule produced by a bacteria that was discovered in soil on Easter Island. By suppressing the mTOR gene, rapamycin was found to be effective in inhibiting cell division. Originally studied as an antifungal and anti-cancer agent, Rapamycin was approved by the FDA for human use to prevent organ transplant rejection.

MTOR’s essential role in natural selection is to signal cell division when it determines that the environment is supportive of reproduction. However, by continuing after reproduction, high levels of these signals lead to functional declines and aging. But when mTOR is blocked, these declines are delayed and lifespan is increased. There are several pharmacological  agents that inhibit mTOR, but Rapamycin appears to be the most effective. In tests on a variety of organisms from yeast to mammals, Rapamycin has been shown to delay and even reverse cellular decline and thereby increase healthspan and lifespan. Dr. Kaeberlein is currently conducting a clinical trial at the University of Washington with companion dogs called TRIAD, “Test of Rapamycin in Aging Dogs.” Initial results are confirming that Rapamycin can slow aging in dogs.