Researchers reveal the secret of the Eternal Life gene
The quest for immortality and eternal youth has been with people for millennia. Now researchers at the Christian Albrechts University in Kiel (CAU) have discovered the genetic key for this in the freshwater polyp Hydra. The tiny cnidarians are known as an organism that shows no aging processes and is potentially immortal.
Because of their immortality, the Hydra freshwater animals are of particular interest for aging research. The Kiel scientists have investigated this special property of the animals and came across the transcription factor Forkhead Box O (FoxO). This can also be found in the human organism and is known as a longevity gene. "In the search for the gene that is responsible for the immortality of the Hydra", according to the doctoral candidate at the CAU and first author of the new study, Anna-Marei Böhm, the researchers came across the "FoxO gene" unexpectedly, of all things The scientists have published their results in the renowned journal "Proceedings of the National Academy of Sciences" (PNAS).
Immortal organism in a finite world The "supposed paradox of an immortal organism in a world in which all life is finite has a relatively simple biological explanation: in these animals, reproduction takes place exclusively asexually through budding," the researchers explain in the current press release the Christian Albrechts University in Kiel. However, this form of multiplication presupposes “that each individual polyp contains stem cells that can constantly divide.” If these stem cells were lost, the tiny animals could no longer multiply. The researchers therefore faced the question of how the Hydra freshwater polyp permanently maintains the function of the stem cells. The scientists from the CAU and the University Medical Center Schleswig-Holstein (UKSH) went on a search together and came across the FoxO gene.
FoxO gene has a major impact on aging In humans, aging is progressing steadily as the stem cells increasingly lose their ability to form new cells over time. The aging tissue can regenerate more and more poorly. The influence of the FoxO gene in this connection has not been conclusively clarified. Using the immortal Hydra freshwater polyps, the researchers have now examined the function of the FoxO gene in more detail. The scientists tested the effects of switching off the gene on the organism of the polyps. They compared ordinary hydras with genetically modified freshwater polyps in which the FoxO gene was either switched off or amplified. Switching off the gene resulted in the animals having significantly fewer stem cells and growing more slowly, the researchers in Kiel write. In addition, the immune system has also changed. "We know of similarly drastic changes in the immune system as in the genetically modified hydras from people in old age," emphasized Professor Philip Rosenstiel from the Institute for Clinical Molecular Biology at the University Hospital Schleswig-Holstein.
Further studies of the immortal polyps planned, study leader Professor Thomas Bosch from the Zoological Institute of the CAU said that for the first time the research group was able to show directly that there is a direct connection between the FoxO gene and aging. "Since particularly active FoxO has already been found in people over a hundred years old, it is very likely a decisive factor in aging - also in humans," Prof. Bosch continued. However, genetic experiments cannot of course be carried out on humans. "How the longevity gene works in detail and what impact the environment has on FoxO" must therefore first be further investigated at Hydra. However, the current findings are already an important step in deciphering the secret of aging in humans.
Preservation of stem cells and immune system crucial for aging According to the researchers, the study results enable two “essential scientific conclusions”: On the one hand, they confirm the crucial role of FoxO in the preservation of stem cells and thus in determining the individual lifespan - both in the original cnidarian and in the animal in humans. On the other hand, they make it clear that "the aging process and the longevity of an organism crucially depend on the preservation of stem cells and the maintenance of a functional immune system", according to the conclusion of the current CAU announcement. (fp)
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Image: The longevity gene was examined on Hydra. The animal is approx. 1 cm tall, copyright / photo: CAU / Fraune.