X-Message-Number: 24358
From: "Basie" <>
Subject: Cause aging found
Date: Thu, 8 Jul 2004 00:03:45 -0400

Mayo Clinic Researchers Identify Gene Regulating Aging And Fertility
ROCHESTER, Minn. -- Mayo Clinic researchers have discovered a gene
responsible for the onset of aging, including age-related disorders such as
infertility, reproductive problems and cataracts. This research, conducted
in genetically modified mice, is promising in helping physicians understand
and treat the same disorders in humans. The findings appear in the July
issue of the journal Nature Genetics. [Baker, D.J. et al. (2004). Nat.
Genet. 36, 744-749. (http://www.nature.com/ng/)].

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Related section: Health & Medicine



The discoveries came as the result of general investigations into possible
genetic causes of cancer. In this case, it was discovered that this
particular gene, called BubR1, governs production of a protein that
modulates physical aging. The mice studied lacked normal levels of that
protein and began to age prematurely.

"Darren Baker in our laboratory found that mutant mice with low amounts of
BubR1 protein live five times shorter than normal mice. They also develop a
variety of age-related disorders at a very young age," says lead
investigator Jan van Deursen, Ph.D., of the Mayo Clinic Departments of
Pediatric and Adolescent Medicine, and Biochemistry and Molecular Biology.

Dr. van Deursen says, "This prompted us to investigate whether BubR1 protein
levels go down as normal mice age naturally -- which is indeed what we
found. Based on these findings, we believe it is the decline of this protein
with time that may trigger some of the physiological effects of aging."

Another Mayo investigator, Karthik Jeganathan, discovered that mice with low
amounts of BubR1 protein are infertile and unable to distribute chromosomes
properly when their germ cells divide. Abnormal numbers of chromosomes in
germ cells are a hallmark of reproductive aging in humans, and the primary
cause of increased still births and birth defects, such as Down syndrome, in
women over 35 years of age. Says Dr. van Deursen, "Given the age-dependent
decline in ovarian BubR1 in mice, it seems reasonable to assume that this
protein may contribute to age-related infertility and certain birth defects
in humans."

In collaboration with Mayo ophthalmologist J. Douglas Cameron, M.D., the
researchers discovered that mice with low amounts of BubR1 also develop
cataracts that are very similar to age-related cataracts in humans. About 20
to 25 percent of individuals at age 65 and older have cataracts of this
type, and 1 million Americans undergo surgery to repair this aging-related
disorder each year.

In addition to Dr. van Deursen, other Mayo Clinic scientists involved in the
investigation were: Darren J. Baker; Karthik B. Jeganathan; J. Douglas
Cameron, M.D.; Michael A. Thompson; Subhash Juneja; Alena Kopecka; Rajiv
Kumar, M.D.; Robert B. Jenkins, M.D., Ph.D.; Piet C. de Groen, M.D.; and
Patrick Roche, Ph.D. The research was supported by a grant from the National
Institutes of Health.

Editor's Note: The original news release can be found here.

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