Cynthia Kenyon on Aging

Journalists aren't supposed to have heros, but New Biology Economy certainly has one scientist that it admires and that is Cynthia Kenyon, a professor of biochemistry and biophysics at the University of California, San Francisco.

Kenyon conducts her research using the C. Elegans soil roundworm as a model organism to study the genetic basis for aging.

In 1981, Kenyon, working as a graduate student in the laboratory of Graham Walker, a professor at the Massachusetts Institute of Technology, identified the genes that are activated in bacteria exposed to DNA damaging agents. Kenyon named the damaged-inducible (Din) genes in order of discovery, with DinB so named because it was the second one she found.

Earlier this month, Walker and his colleagues published research in the Jan. 12, 2006, issue of the journal Nature that finally reveals – some 25 years later -- what exactly DinB does. The research indicates that DinB is proficient at copying over a particular kind of damage to the G nucleotide.

"In general, we think that nature evolved this function to help us survive DNA damage that would otherwise kill us," said Walker in a statement from the Howard Hughes Medical Institute. "It's probably a kind of damage that all cells encounter frequently in life.”

While it took 25 years to go from discovery of this gene to learn what it does, Kenyon's work continues. In 1993, Kenyon found that a single genetic change could double the lifespan of C. elegans. Kenyon's research has shown that aging in the worm is regulated by hormonal pathways that have counterparts in humans. By manipulating genes and cells, she has been able to extend the lifespan and period of youthfulness in worms up to six-fold. Specifically, her research indicated that mutations in the worm’s daf-2 gene, which encodes an insulin/IGF-1-like receptor, can double the lifespan of C. elegans.

Her insight into the response pathway for insulin IGF-1 has convinced her to alter her own diet, she said in an interview in 2004.

“I eat a low-carb diet. We gave our worms sugar and it shortened their life span. So, I’ve been on this diet for three years. I have a great serum profile. And, they have done studies now that are upholding this. They took two obese groups of people and put one half of them on a low-carb diet, a very stringent version of the Atkins diet where you eat only 30 grams of carbs a day, and the other half on a low-fat diet. Neither group actually turned out to lose much weight at the end of a year. But, the low-carb people had a much better responsiveness to insulin and [beneficial] triglyceride levels,” she said.

Kenyon has recently taken her research on animal aging to the next step, with mice. She has been able to increase their lifespan by up to 25 percent using similar mutations as in her research on C. elegans, according to an article in The California Aggie student newspaper at Cal-Davis.

Kenyon presented two free lectures at the University of California, Davis, on Jan. 24 and Jan. 25. We wish we could have been there as this kind of genetic research is an exciting and promising part of the New Biology Economy.