Between Life and Death
Biologists have discovered a gene that causes aging.
Sooner or later, everyone is getting older, but it turns out, this is not to blame for his bad temper, poor nutrition, stress, or the environment. The aging of the organism is a special gene which is present in all members of the human race. With each passing year, he was “off” more stem cells responsible for updating the tissues of our body.
Immortality and the aging gene
Until recently, scientists thought that this gene has beneficial effects on health, preventing the development of cancerous tumors. Alas, it turned out, a gene with a boring name INK4a is responsible for the process of our dying.
To protect people from cancer, which will inevitably develop, if the stem cells will be shared freely, INK4a gradually reduces the ability of these cells to reproduce. But these cells renew our body.
By the conclusion of the role of INK4a both came three independent teams of U.S. researchers recently published its report in the journal Nature. Despite the fact that their discovery was the result of experiments on genetically modified mice in which this gene was removed, researchers are confident that the identification of features characteristic of the human body: physical and mental degradation, characteristic of old age, is directly linked to the performance of gene INK4a, violates normal functioning of stem cells.
“I think that aging is not a random process, reinforced the negative impact of environment on man. This whole program is built into the human body. Anti-cancer program “, – underlines one of the authors of the report of Professor Norman Sharpless of the University of North Carolina.
Will their discovery to develop new treatments for premature aging and increase life expectancy, it is not clear even to scientists. Obviously, only that it is very distressing those researchers who had hoped to use stem cells of adult patients as an elixir of youth. In addition, the opening once again proves that the stem cells of adults are not suitable for the creation of new tissues and organs – the so-called cell transplants: are required in their embryonic counterparts.
INK4a gene plays a key role in the protection of the organism from cancer. It produces two “smart” protein, determining which cells to allow sharing, and what not. As biologists have found, over the years the content of one of these proteins in the body is greatly increased. According to Professor Sharpless, in his time he was struck by the fact that the cells of 70-year old man produces 10 times more protein p16INK4, than the cells of twenty.
To understand why this happens, the scientist brought breed of transgenic mice in which no gene INK4a, produced by this protein. His plan was to find out if the absence of the gene increases the activity and life expectancy of hematopoietic stem cells.
Upon learning that Professor Sean Morrison of the University of Michigan conducts similar experiments with cells of the brain, and Professor David Skedden from the Harvard School of Medicine for the same purpose studying cells of the pancreas that produce insulin, Sharpless has provided them with their transgenic mice.
The research results were absolutely identical, it was decided to publish together. Scientists have evidence that in the absence of the gene INK4 stem cells acquire an exceptional ability to multiply and form a cancerous tumor. Genetically modified mouse Professor Sharpless all of them were prone to cancer, which developed from them already in the second year of life.
Apparently, the doctors, who hope to learn how to manage the processes of aging and prolong human life, “turning off” in his genes INK4, will also have to look for new ways to combat cancer. “Free cheese comes only in a mousetrap. We’re all doomed “- that is disappointing verdict Sharpless.
However, according to his colleague Professor Skeddena, output still there. Physicians and biologists must turn off INK4 temporarily, with the help of drugs which, although not yet invented. This technique will be conducive to the division of stem cells, without increasing the risk of developing cancer. There are other safe ways to extend youth. For example, the extraction of stem cells of the patient, their reproduction in the laboratory and put them back into the body for the formation of new tissue.
But in the future. Meanwhile, new data, explaining how the regulated wonderful capacity for renewal, characteristic of stem cells to help create products that improve the characteristics of cell transplants, which are usually poorly acclimatized in the body of older people.