Telomeres and telomerase – A genetic marker of aging

Eternal youth may be yours. Telomerase the immorality enzyme is in under research by scientists. Telomeres are the chromosomal structures present at the end of chromosomes and behave as a protective cap. Telomere behaves as a buffer during chromosomal replication.  TFAGGG, TTAGGG, TFAGGG, TTAGGG, this is the figure of genetic code which is repeated thousands of times in telomeres. Research studies evaluated the fact that sequences of nucleotides shorten gradually with age during cell replication and division. Telomere shows gradual shortening in length

Aging of the cell and the programmed death that follows (apoptosis) is called cellular senescence and is normal for all somatic cells (Greider CW,Telomeres, telomerase, and cancer.1996).

So it is believed that due to continuous shortening of telomere throughout life, there is consequent cell damage. The cell is unable to duplicate itself efficiently. These cause events in a regular sequential order from cellular damage to subsequent aging in a slow process which leads to death. Telomere is considered as the gentic marker of biological aging.

Telomerase, a telomere protective enzyme, plays an important role in anti- aging. Different researches on the aging process reveal that immortal cells like cancer cells keep on dividing indefinitely and lengthening the telomeres due to this enzyme the telomerase.

Cancer cells do not lose telomere length and are referred to as “immortal”(    Shea-Herbert B, et al 2002)

Telomerase, an enzyme for telomeres, is normally present in cells which need rapid proliferation with increase activity of telomerase.   

However, these cells clearly do not live forever and therefore must lose telomere length despite high levels of telomerase activity during certain cycles in their lifespan (Harley CB, et al 1990)

It has been evaluated that people are genetically susceptible to aging which is further associated with environmental factors like obesity, smoking and lack of exercise.  The best known supplements for anti-aging like vitamin E, vitamin D or omega three fatty acids claim to activate the telomerase activity in the cell and help in maintaining the length of telomeres on chromosomes. Telomerase supplements are itself available in the market as anti-aging product. Telomerase supplements are synthesized from live cell cultures. Telomerase enzyme promises strong anti-aging role.

 

Reference:

Greider CW, Blackburn EH. Telomeres, telomerase, and cancer. Sci Am 1996 Feb;274 (2):92-7.

Harley CB, Futcher AB, Greider CW Telomeres shorten during aging of human fibrobasts. Nature 1990;345:458-60

Shea-Herbert B, Pongracz K, Shay J, and Grayaznov S. Oligonucleotide N3′-P5′ phosphoramidates as efficient telomerase inhibitors. Oncogene 2002; 21: 638-43.

Author: Dr. Rubina Mushtaq

Thanks to Thomas Splettstoesser for allowing the use of the image

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