For as long as mankind has been on this earth, we have tried to conquer death and unlock immortality. Books, movies, television shows, ancient mythology and cosmetic magazines all paint their own images of the “Fountain of Youth
” and the everlasting youth that its mystical water provides.
Well, it seems we are one step closer to deciphering the mystery of our mortality, as researchers at Mayo Clinic have successfully eliminated cells that have stopped growing, which ultimately could prevent various age-related disorders, diseases and disabilities.
Over fifty years ago, scientists discovered that cells have a limited number of times that they can divide, and once they reach this limit, they stop dividing. Once the cells can no longer divide, they reach a state called cellular senescence
, which means the cell can neither die nor continue to multiply. Instead, it just accumulates with age inside the body. These senescent cells produce chemicals that damage any nearby cell, and can cause tissue inflammation
. While the immune system removes these old cells fairly regularly, over time it becomes less effective. As the person ages, more senescent cells accumulate. Scientists believe that this limit to cell division is a mechanism meant to prevent cells from growing out of control and becoming cancerous.
The report, which was published in the online journal Nature
along with commentary, was led by senior author Jan van Deursen, Ph.D., a molecular biologist at the Mayo Clinic and the Vita Valley Professor of Cellular Senescence. "Our discovery demonstrates that in our body cells are accumulating that cause these age related disorders and discomforts," explains Dr. van Deursen. He believes that intervening the effects of these senescent cells, or at least blocking their effects, could lead to individuals feeling more vital and healthier.
For the experiments, the Mayo Clinic researchers produced genetically engineered mice that developed many senescent cells. These particular cells contained a special molecule called caspase 8
that was only activated in the presence of a drug that did not have any effect on normal cells. Exposure to the drug caused the caspase 8 in the mice to activate, and promptly began drilling holes in the old cell membranes, effectively killing the senescent cells that lay dormant. When extending this treatment to the rest of its life, the mice had age related disorders (such as muscle loss and weakness) significantly reduced.
Another author of the study, James Kirkland, M.D., Ph.D., head of Mayo Clinic's Robert and Arlene Kogod Center on Aging and the Noaber Foundation Professor of Aging Research, has high hopes for the treatment. Kirkland is confident that attacking these senescent cells could eventually lead to breaking the link between aging mechanisms and diseases associated with old age, such as heart disease, stroke, dementia and various cancers