How Cells Age

Posted on November 29, 2008  Comments (4)

How Cells Age

A new study by Harvard Medical School researchers reveals that the biochemical mechanism that makes yeast grow old has a surprising parallel in mice, suggesting it may be a universal cause of aging in all organisms.

In young organisms, SIRT1 effectively doubles as a gene-expression regulator and a DNA repairer. But when DNA damage accumulates—as it does with age—SIRT1 becomes too busy fixing broken DNA to keep the expression of hundreds of genes in check. This process is so similar to what happens in aging yeast that its discoverers believe it may represent a universal mechanism of aging.

Harvard researchers gain new insight into aging

Aging may be a case of neglect — an absentee landlord at the cellular level that allows gene activity to go awry, according to a study published today.

Scientists have long known that aging causes gene expression to change, and DNA damage to accumulate. But now, research led by Harvard Medical School scientists explains the connection between the two processes in mammals.

The paper, published in the journal Cell, found that a multi-tasking protein called SIRT1 that normally acts as guardian of the genome gets dragged away to DNA fix-it jobs. When the protein abandons its normal post to work as a genetic handyman, order unravels elsewhere in the cell. Genes that are normally under its careful watch begin to flip on.

“What this paper actually implies is that aspects of aging may be reversible,” said David Sinclair, a Harvard Medical School biologist who led the research. “It sounds crazy, but in principle it should be possible to restore the youthful set of genes, the patterns that are on and off.”

The study is just the latest to draw yet more attention to sirtuins, proteins involved in the aging process

Aging is fascinating. By and large people just accept it. We see it happen to those all around us, without exception. But what causes biological aging? It is an interesting area of research.

Related: lobsters show no apparent signs of agingOur Genome Changes as We AgeMillennials in our Lifetime?Radical Life Extensionposts on cells

4 Responses to “How Cells Age”

  1. Anonymous
    December 7th, 2008 @ 2:31 am

    It all sounds great, never getting old, and staying healthy.
    One thing to think about though, would we ever die? and would we still have children?
    Where would we have to draw the line?
    With over 6 Billion people now in this world, would it come down to living forever, or having children?
    certainly we wouldn’t be able to do both, for we would all too soon end up with a nightmare world devoid of any place where we could be alone, probably without enough food for everyone,
    (for real, not just the population control used now by claiming a lack of enough to feed everyone).
    Starvation can kill just as surely as growing old does.
    Like I said, just something to think about.

  2. Sara Connor
    December 9th, 2008 @ 1:19 pm

    I read the synopsis of this study as well and found it quite interesting. As an older mom who is expecting, there is an age at which a woman’s risk factors start to increase for genetic abnormalities in the baby, which is 35 years old. That is not to say that a woman in her late thirties cannot conceive and have a healthy baby, many women do each year. Doctors have seen the correlation between increased chromosomal defects and mother’s age.

    I have for a long time believed that this was related to the aging process. In the light of the study it makes even more sense. In that SIRT1 becomes overwhelmed in repairing broken DNA that there is a higher chance that defective genes in the DNA get turned on.

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