Not quite, but we have a new
route to restoring cells or at least yeast cells by fifty percent. This adds one more research avenue.
I believe that it is now probable
that folks who survive the next decade will have a life lengthening protocol
available to them that will at least allow a person to live past their one
hundredth birthday while remaining in their prime in terms of health. It may allow an actual extension to around
120 for some.
We know just too much about cells
today and are becoming gifted at manipulating molecules at an accelerating pace
that the above almost looks easy. What
will not be easy is to get it into the hands of the public, but even that will
likely change in the next decade.
by Staff Writers
Collaborations between Johns Hopkins and National Taiwan University
researchers have successfully manipulated the life span of common,
single-celled yeast organisms by figuring out how to remove and restore protein
functions related to yeast aging.
A chemical variation of a "fuel-gauge" enzyme that senses
energy in yeast acts like a life span clock: It is present in young organisms
and progressively diminished as yeast cells age.
In a report in the September 16 edition of Cell, the scientists
describe their identification of a new level of regulation of this age-related
protein variant, showing that when they remove it, the organism's life span is
cut short and when they restore it, life span is dramatically extended.
In the case of yeast,
the discovery reveals molecular components of an aging pathway that appears
related to one that regulates longevity and lifespan in humans, according to
Jef Boeke, Ph.D., professor of molecular biology, genetics and oncology,
and director of the HiT Center and Technology Center for Networks and Pathways,
Johns Hopkins University School of Medicine.
"This control of longevity is independent of the type described
previously in yeast which had to do with calorie restriction," Boeke says.
"We believe that for the first time, we have a biochemical route to
youth and aging that has nothing to do with diet."
The chemical variation, known as acetylation because it adds an acetyl
group to an existing molecule, is a kind of "decoration" that goes on
and off a protein - in this case, the protein Sip2 - much like an ornament can
be put on and taken off a Christmas tree, Boeke says. Acetylation can
profoundly change protein function in
order to help an organism or system adapt quickly to its environment.
Until now, acetylation had not been directly implicated in the aging
pathway, so this is an all-new role and potential target for prevention or
treatment strategies, the researchers say.
The team showed that acetylation of the protein Sip2 affected longevity
defined in terms of how many times a yeast cell can divide, or
"replicative life span." The normal replicative lifespan in natural
yeast is 25. In the yeast genetically modified by researchers to restore
the chemical modification,
life span extended to 38, an increase of about 50 percent.
The researchers were able to manipulate the yeast life span by mutating
certain chemical residues to mimic the acetylated and deacetylated forms of the
protein Sip2. They worked with live yeast in a dish, measuring and comparing
the life spans of natural and genetically altered types by removing buds from
the yeast every 90 minutes.
The average lifespan in normal yeast is about 25 generations, which
meant the researchers removed 25 newly budded cells from the mother yeast cell.
As yeast cells age, each new generation takes longer to develop, so each round
of the experiment lasted two to four weeks.
"We performed anti-aging therapy on yeast," says the study's
first author, Jin-Ying Lu, M.D., Ph.D., of National Taiwan
University . "When we
give back this protein acetylation, we rescued the life span shortening in old
cells. Our next task is to prove that this phenomenon also happens in mammalian
cells."
The research was supported by the National Science Council, National Taiwan
University Hospital ,
National Taiwan
University , Liver Disease Prevention
and Treatment Research Foundation of Taiwan , and the NIH Common Fund.
Authors on the paper, in addition to Boeke and Lu, are Yu-Yi Lin,
Jin-Chuan Sheu, June-Tai Wu, Fang-Jen Lee, Min-I Lin, Fu-Tien Chian, Tong-Yuan
Tai, Keh-Sung Tsai, and Lee-Ming Chuang, all of National Taiwan University; Yue
Chen and Yinming Zhao, both of the University of Chicago; and Shelley L.
Berger, Wistar Institute.
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