
Longevity Tied to Genes That Preserve Tips of Chromosomes
ScienceDaily (Nov. 15, 2009) — A team led by researchers at Albert Einstein College of Medicine of Yeshiva University has found a clear link between living to 100 and inheriting a hyperactive version of an enzyme that rebuilds telomeres -- the tip ends of chromosomes.
The findings appear in a recent issue of the Proceedings of the National Academy of Sciences.
Telomeres play crucial roles in aging, cancer and other biological processes. Their importance was recognized last month, when three scientists were awarded the 2009 Nobel Prize in Physiology and Medicine for determining the structure of telomeres and discovering how they protect chromosomes from degrading.
Telomeres are relatively short sections of specialized DNA that sit at the ends of all chromosomes. One of the Nobel Prize winners, Elizabeth Blackburn, Ph.D., of the University of California at San Francisco, has compared telomeres to the plastic tips at the ends of shoelaces that prevent the laces from unraveling.
Each time a cell divides, its telomeres erode slightly and become progressively shorter with each cell division. Eventually, telomeres become so short that their host cells stop dividing and lapse into a condition called cell senescence. As a result, vital tissues and important organs begin to fail and the classical signs of aging ensue.
In investigating the role of telomeres in aging, the Einstein researchers studied Ashkenazi Jews because they are a homogeneous population that was already well studied genetically. Three groups were enrolled: 86 very old -- but generally healthy -- Gil Atzmon, Ph.D.people (average age 97); 175 of their offspring; and 93 controls (offspring of parents who had lived a normal lifespan).
"Telomeres are one piece of the puzzle that accounts for why some people can live so long," says Gil Atzmon, Ph.D., assistant professor of medicine and of genetics at Einstein, Genetic Core Leader for The LonGenity Project at Einstein's Institute for Aging Research, and a lead author of the paper. "Our research was meant to answer two questions: Do people who live long lives tend to have long telomeres? And if so, could variations in their genes that code for telomerase account for their long telomeres?"
The answer to both questions was "yes."








