New research highlights importance of telomere activity in aging
Researchers at the National Institutes of Health (NIH) say they have identified a new pathway that sets the clock for programmed aging in normal skin and body cells, in a study that was published the Journal of Clinical Investigation.
Previous scientific research has already documented how telomeres wear away during cell division, which leads to degradation and eventually the death of the cell. Ultimately this leads to age-related cell damage, which in the case of skin, manifests itself in fine lines and wrinkles.
Specifically the study has focused on the interaction between a toxic protein called progerin and telomeres, identifying how this toxin caps the ends of the telomeres.
Progerin acts as a toxin and shortens telomeres
Progerin is a mutated version of a normal cellular protein called lamin A, which is encoded by the normal LMNA gene, the researchers point out. Lamin A helps to maintain the normal structure of a cell's nucleus, the cellular repository of genetic information.
Scientific studies have previously documented that the shorter or damaged telomeres tend to stimulate or activate production of progerin, which is the trigger for the cell damage. The more the telomere shortens, the higher the rate of progerin production.
‘Our sense from the start was that progeria had a lot to teach us about the normal aging process and clues about more general biochemical and molecular mechanisms," NIH Director Dr. Francis Collins, M.D., Ph.D., and a senior author of the current paper.
Study drew of premature aging disease progeria
The study shows that the mutation that causes progeria – a rare disease that leads to premature aging in children - strongly activates the splicing of lamin A to produce the toxic progerin protein, leading to all of the features of premature aging suffered by children with the disease.
Interestingly, the researchers also observed that modifications in the splicing of LMNA are at play in the presence of the normal gene, a process known as RNA, and one that alters how a normal cell processes genetic information when turning into a protein.
The researchers have documented that this alteration in RNA splicing affects the processing of the LMNA messenger RNA, leading to an accumulation of the toxic progerin protein, the shortening of the telomeres, and cell degradation.
Telomere shortening is key
"Telomere shortening during cellular senescence plays a causative role in activating progerin production and leads to extensive change in alternative splicing in multiple other genes," said lead author Kan Cao, Ph.D., an assistant professor of cell biology and molecular genetics at the University of Maryland, College Park.
Telomere Biology has become a hot topic in anti-aging skin care research. In a study released on November 28th 2010, in the online journal Nature, a team of researchers at Harvard Medical School reported on the first reversal of the aging process in a mammal.
By reactivating telomerase, they rejuvenated worn out organs in mice that were the equivalent biological age to 80 year old humans.
