[If you cannot see the flash video below, you can click here for a high quality mp4 video.]
Interviewee: Christoph Westphal, Sirtris Pharmaceuticals
By Heather Mayer
“This is the first potentially fundamental, root cause of aging that we’ve found,” Sinclair said in a Harvard press release. “There may very well be others, but our finding that aging in a simple yeast cell is directly relevant to aging in mammals comes as a surprise.”
Also on ScienCentral
Ten years ago, Sinclair, working with Leonard Guarente, discovered a yeast gene, that reversed the effects of aging. More recently, they gave mice an extra copy of the mammalian version of the gene, called SIRT-1, confirming their hypothesis that sirtuin, as well as caloric restriction, leads to a longer lifespan.
When stimulated by the red wine chemical resveratrol, or caloric restriction, sirtuins seem to have positive effects on aging and health, according to Sinclair’s research.
The studies showed that sirtuins affect the aging processes in two different ways. They help regulate gene activity, as well as help repair DNA damage.
Regulating gene activity is extremely important because if some genes are turned on at the wrong time, there can be damage done to cells or organs. But, while a sirtuin is off repairing DNA damage — from UV rays or free radicals — it’s not monitoring the genes. This allows the 618 chromatin, which packages the genes, to come apart, allowing the unwanted gene expression.
As the mice aged, Sinclair’s team found there is more DNA damage, forcing sirtuins to leave their cell posts more frequently, allowing more genes to be expressed when they shouldn’t be. Once extra doses of sirtuins were administered to the mice, their average lifespan increased from 24 to 46 percent, according to the study.
Leonard Guarente, Novartis Professor of Biology at MIT, who is not an author on the paper, says in the press release: "This should lead to new approaches to protect cells against the ravages of aging by finding drugs that can stabilize this redistribution of sirtuins over time."
Reseveratrol clinical trials
CALERIE Clinical trials