Cynthia Kenyon

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Cynthia Kenyon
Fields Biologist
Institutions University of California, San Francisco (UCSF)
Alma mater Massachusetts Institute of Technology
Doctoral advisor Graham Walker
Notable students Andrew Dillin
Known for Aging in Caenorhabditis elegans.
Notable awards

National Academy of Sciences

Dan David Prize

Cynthia Jane Kenyon (born c. 1955) is an American molecular biologist and biogerontologist known for her genetic dissection of aging in a widely used model organism, the tiny worm Caenorhabditis elegans.

Career[edit]

Cynthia Kenyon graduated valedictorian in chemistry and biochemistry from the University of Georgia in 1976. She received her PhD in 1981 from MIT where, in Graham Walker's laboratory, she was the first to look for genes on the basis of their activity profiles, discovering that DNA-damaging agents activate a battery of DNA repair genes in E. coli. She then did postdoctoral studies with Nobel laureate Sydney Brenner at the MRC Laboratory of Molecular Biology in Cambridge, England, studying the development of C. elegans.

Since 1986 she has been at the University of California, San Francisco (UCSF), where she was the Herbert Boyer Distinguished Professor of Biochemistry and Biophysics and is now an American Cancer Society Professor.

Her early work led to the discovery that Hox genes, which were known to pattern the body segments of the fruit fly Drosophila, also pattern the body of C. elegans. These findings demonstrated that Hox genes were not simply involved in segmentation, as thought, but instead were part of a much more ancient and fundamental metazoan patterning system.

M. Klass discovered that lifespan of C. elegans could be altered by mutations, but Klass believed that the effect was due to reduced food consumption (calorie restriction).[1] Thomas Johnson later showed that the 65% life extension effect was due to the mutation itself rather than due to calorie restriction.[2] In 1993, Dr. Kenyon's discovery that a single-gene mutation (Daf-2) could double the lifespan of C. elegans and that this could be reversed by a second mutation in daf-16m,[3] sparked an intensive study of the molecular biology of aging. Dr. Kenyon's findings have led to the discovery that an evolutionarily-conserved hormone signaling system influences aging in other organisms, perhaps also including mammals.

Kenyon has received many honors, including the King Faisal Prize for Medicine, the American Association of Medical Colleges Award for Distinguished Research, the Ilse & Helmut Wachter Award for Exceptional Scientific Achievement, and La Fondation IPSEN Prize, for her findings. She is a member of the U.S. National Academy of Sciences and the American Academy of Arts and Sciences. She is now the director of the Hillblom Center for the Biology of Aging at UCSF. She is also one of featured biologists in the 1995 science documentary Death by Design / The Life and Times of Life and Times.

Personal diet[edit]

Kenyon's research prompted her to make personal dietary changes. She stopped eating high glycemic index carbohydrates when she discovered that putting sugar on the worms' food shortened their lifespans.[4]

Kenyon follows a low glycemic index diet similar to the Atkins diet[4] and the South Beach Diet.[5]

No desserts. No sweets. No potatoes. No rice. No bread. No pasta. When I say ‘no,’ I mean ‘no, or not much,’ she notes. Instead, eat green vegetables. Eat the fruits that aren't the sweet fruits, like melon. Bananas? Bananas are a little sweet. Meat? Meat, yes, of course. Avocados. All vegetables. Nuts. Fish. Chicken. That's what I eat. Cheese. Eggs. And one glass of red wine a day.[6]

But the diet is unproven, she cautions, and she's not recommending it for all. Nevertheless, she's pleased with its performance for her. 'I have a fabulous blood profile. My triglyceride level is only 30, and anything below 200 is good.'[6]

You have to eat something, and you just have to make your best judgment. And that's my best judgment. Plus, I feel better. Plus, I'm thin—I weigh what I weighed when I was in college. I feel great —you feel like you're a kid again. It's amazing.[6]

In the past, Kenyon had also briefly experimented with a calorie restriction diet for two days, but couldn't stand the constant hunger.[4]

Gene manipulation[edit]

Kenyon's lab is focusing on extending life by inducing gene mutations or killing part of a specific worm cell. Kenyon showed that although the daf-16 gene is required for life extension in C. elegans, the life extension effect can be uncoupled from dauer growth arrest.[3]

The company she founded, Elixir Pharmaceuticals, is trying to make a pill that would slow down the process that makes people age. It would mimic gene manipulation.

See also[edit]

Notes and references[edit]

  1. ^ Klass MR (1983). "A method for the isolation of longevity mutants in the nematode Caenorhabditis elegans and initial results". MECHANISMS OF AGEING AND DEVELOPMENT 22 (3-4): 279–286. PMID 6632998. 
  2. ^ Friedman DB, Johnson TE (1988). "A mutation in the age-1 gene in Caenorhabditis elegans lengthens life and reduces hermaphrodite fertility" (PDF). Genetics (journal) 118 (1): 75–86. PMC 1203268. PMID 8608934. 
  3. ^ a b Kenyon C, Chang J, Gensch E, Rudner A, Tabtiang R (1993). "A C. elegans mutant that lives twice as long as wild type". Nature (journal) 366 (6454): 461–464. doi:10.1038/366461a0. PMID 8247153. doi:10.1038/366461a0. 
  4. ^ a b c Kingsland, J.: "I Want to Live Forever", New Scientist, Issue 2417, October 18, 2003.
  5. ^ Platoni, K: "Live, Fast, Die Old", East Bay Express, January 18, 2006.
  6. ^ a b c O'Neill B: "In Methuselah's Mould", PLoS Biology Vol. 2, No. 1, e12 doi:10.1371/journal.pbio.0020012

External links[edit]