You're only as old as your genes - Genetic fingerprint could pinpoint fittest organ donors.

news@nature.com ^ | 21 July 2006 | Helen Pearson

[neverdem]

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Published online: 21 July 2006; | doi:10.1038/news060717-18

You're only as old as your genes

Genetic fingerprint could pinpoint fittest organ donors.

Helen Pearson

Close up: ageing can be seen in our cells, chromosomes and genes.Credit: DR GOPAL MURTI / SCIENCE PHOTO LIBRARY

A fingerprint of gene activity could reveal the true 'youthfulness' of our kidneys, hearts and muscle, regardless of our biological age. The technique might one day be used to find healthy organs for transplants or to warn us of impending disease.

It's hard to tell, particularly on a cellular level, whether a young and healthy body conceals a withering heart — or conversely, whether an old man has a vigorous ticker like that of a younger man.

Stuart Kim of Stanford University Medical Center, California, says that a simple genetic test might do the trick. He and his colleagues have found a set of genes whose activity reveals how well organs are operating, regardless of their owner's actual age.

The team analysed the activity of thousands of genes in 81 muscle samples from people aged between 16 and 89. They pulled out a set of 250 genes whose activity goes markedly up or down with age.

When they compared the activity of these genes with the muscle fitness of individuals, measured by the size of their muscle fibers, they found that the genetic profile, rather than a person's age in years, was a more accurate indicator of fitness.

Body clock

The speed with which our cells and bodies deteriorate is determined partly by the genes we inherit from our parents and partly by the ravages of living. These factors can change the rate at which certain genes manufacture proteins, and other aspects of the cell's machinery. Some studies, for example, have shown that the ends of chromosomes, called telomeres, decay over time and do so faster in those who indulge in unhealthy activities such as smoking.

Kim's team found one 64-year-old man who had a pattern of gene activity more like that of a younger person. Indeed, under the microscope, his muscle appeared young; it contained bigger 'fast twitch' fibers that are good for sprinting and more prevalent in young muscle. The findings are reported in the journal PLoS Genetics¹.

In an earlier study, the same group detected a 78-year-old woman with a kidney more like that of a centenarian, according to her genetic profile and an inspection of the tissue under the microscope².

The researchers found that aging affects some of the same genes across many different tissue types and in many different animals. One group of genes, which is involved in generating energy in the cell's mitochondria, quiet down with age in human muscle, kidney and brain tissue, and also in aging mice and flies, even though these animals have very different lifespans.

It may be that this pathway is a weak spot in the cell that is particularly vulnerable to aging, Kim says.

Healthy living

Kim says that such techniques could one day be used to identify donor organs that are normally ruled out because of the donor's age but may actually be in good working order. "We could open up a huge new pool of donors," Kim says, who is planning a study to test this idea.

In future, a routine blood test at the doctor's office could also reveal the true working condition of organs, allowing patients to modify their lifestyle or diet to rejuvenate their bodies.

But to do this researchers will need to find a way to gauge the activity of an organ's genes from molecules in the blood rather than from a tissue sample, which is difficult to obtain.

Visit our newsblog to read and post comments about this story.

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References

1. Zahn J.M., et al. PLoS Genetics, 2. e115 (2006).

2. Rodwell G.E.J., et al. PLoS Biology, 2. e427 (2004).

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		© 2006 Nature Publishing Group | Privacy policy

[neverdem]

References (freebies)

Transcriptional Profiling of Aging in Human Muscle Reveals a Common Aging Signature

A Transcriptional Profile of Aging in the Human Kidney click on the sidebar for full text in HTML or PDF.

[nmh]

HOw can they reveal ANYTHING when fingerprints NEVER change?

I think this is bunk ... .

[martin_fierro]

I think you're drunk.

[neverdem]

HOw can they reveal ANYTHING when fingerprints NEVER change?

Who ever proved that, or is it just an assumption?

[INSENSITIVE GUY]

Lets see now.They want everybody to provide them(doctors&hospitals)with the inventory(free organs)so they can make an outlandish profit!

[coconutt2000]

I think if I live long enough, I might be able to get one of them regenerative treatments I read about in one of my sci-fi novels.

Then I'll live to be a few hundred years old, and maybe even collect Social Security.

[neverdem]

WHETHER IN MICE OR MEN, ALL CELLS AGE THE SAME, STANFORD STUDY FINDS Stanford's press release and thread, the thread has an interesting, animated link on telomerase in comment# 8.

Brain's Stem Cells Hold Clues to Cancer

FReepmail me if you want on or off my health and science ping list.

[Crim]

Scary crap....in light of the fact that the aussies are starting to prep NON brain dead people for organ "donation"....

How long until this extends to healthy people?

Imagine opening a strange envolope...the letter reads..

"congratulations....you have been selected for organ donation...you have 24 hrs to put you affairs in order and report to the nearest organ recycling center for extraction."

The office of organ administration.

I mean really...how many falun gong can there be?

[neverdem]

ping

[trek]

"Lets see now.They want everybody to provide them(doctors&hospitals)with the inventory(free organs)so they can make an outlandish profit!"

I agree. The "donor business" has become an evil. I recently removed my donor card from my wallet and rejoined the "dust onto dust" crowd.

[nmh]

"I think you're drunk."

I take an slur from YOU, as a compliment.

We couldn't be more different.

[nmh]

It's just more junk science posing as objective science.

[nmh]

"I think you're drunk."

Correction:

I take a slur from YOU, as a compliment.

We couldn't be more different.

I am ever so thankful that I am not like you at all.

[MikefromOhio]

I wasn't entirely sure that the age of an organ affected it's function.

Like say a Liver or a Pancreas or whatnot....but those are affected by lifestyles and other types of ailments/environmental conditions.

[martin_fierro]

Correction

For someone who's apparently seeing double, would it kill ya to read the article once before adding your particular brand of clueless sanctimony.

[Born Conservative]

[Born Conservative]

Did you ever think that they just might want "everybody" to provide them with the "inventory" so that people needing the organs might be able to live? Unfortunately, until science has evolved into being able to grow/clone organs from the DNA of the patient, that's the best system that's available. Unless, that is, you have a better suggestion....

[neverdem]

It's just more junk science posing as objective science.

How do you determine junk science?

[nmh]

"How do you determine junk science?"

When it makes absolutely no sense and defies the laws of science. What puzzles me is why you have to ask. Surely you have some knowledge of science and common sense doesn't hurt either. Both are in short supply, of late ... .

[neverdem]

When it makes absolutely no sense

Neither quantum mechanics nor general relativity made apparent sense, are irreconcilable, yet quantum mechanics works fine when applied to subatomic physics, and general relativity works fine when applied to astronomy. Because of that irreconcilability, physicists have developed the as yet untestable string theory, according to Brian Greene.

and defies the laws of science.

What laws might that be?

What puzzles me is why you have to ask.

IMHO, the honest student of science is the first to admit, "I don't know." The simple fact is that we don't know, by definition, what we don't know. But, we keep on learning new stuff. Just look at what has been learned in the last decade about RNA.

siRNAs can function as miRNAs