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Of Old Mice and Men

Published: January 14, 2012

The Mayo Clinic, famed for its cutting edge medical care, has conducted research that is being called revolutionary in the field of aging. Dr. Darren Baker’s work involved genetically engineered mice, but could be a breakthrough for homo sapiens. According to a recent article in Nature a strain of mice were developed that were afflicted a genetic disorder that produced the mouse equivalent of progeria, that strange disease that causes premature aging. As with humans afflicted with progeria young animals develop conditions associated with old age.

A certain molecule is produced when cells get old that prevents further cell divisions. This is one method cells use to prevent the runaway growth of cancer. The Mayo team cleverly figured out a way to induce cells that switched on the gene for the molecule to self-destruct. They did this by slipping a gene for another protein very close to the one producing the age-related molecule. The new gene was activated by the same switch that turned on the age molecule. When they exposed that protein to a drug it proved deadly to the cell. So it was the old cells could be made to selectively commit suicide.

No one was sure what selectively killing the old cells would do, but it so happened that the mice slowed their too-rapid aging in a spectacular way. Their muscles remained strong, their fatty tissues did not waste as fast and they did not develop cataracts. The effect was more pronounced the sooner in life the mice were given the cell killing drug, but older mice still benefited.

This approach is different to methods employed previously which have been based on either finding a way for cells to divide longer (with an accompanying risk of cancer) or suppressing chemicals the cell produces that cause damage via inflammation.

This new method is related to the latter approach however. The old cells killed by this technique were causing harm to nearby cells via an inflammatory effect. In the absence of the chemicals (the cellular equivalent of a fire alarm that turns on a sprinkler to douse the flames) the younger cells stayed healthier.

Tinkering with an organism’s life span is surely problematic. There are reasons why we are not immortal. This method raises the possibility that a healthier life can be extend in time. To my mind this is the cellular equivalent of the face lift that smooths wrinkles. After the procedure you are left with less material than what you began with, which itself is potentially a problem.

In this case the fewer cells remaining will also age and stop dividing, but while they live they suffer fewer untoward effects from molecules from those old cells and the inflammatory response they induce. So while one might not live longer one could experience a healthier, more vigorous old age. When people talk about living to 150 nobody has in mind living out 60 or so years as a 90 year-old

This experiment needs to be repeated. First on mice that are more normal than the progeria strain. Some mice strains live 3 plus years vs the normal two year life-span so they are the next logical candidates. This experiment has a long way to go before benefits to human health can made a reality, but it is exciting. A whole new approach to dealing with age has been opened up.

Photo Credit: TEASSARE TS Rogers Illustration and Design