Telomerase: the Secret to Reverse Aging

In 2009, Elizabeth Blackburn, Carol Greider, and Jack Szostak were awarded the Nobel Prize in medicine for discovering telomeres along with the enzyme, telomerase, which helps promote the growth of telomeres. Telomeres are located at the ends of a DNA strand in order to protect the crucial parts of the DNA. During DNA replication, the ends of the DNA strand are usually cut off because DNA polymerase III does not replicate them. The reason for this is because during DNA Replication, DNA polymerase III lands on the end of the strand causing replication to fail at that ending strand. Telomeres counter this by serving as “filler” DNA because they do not code for anything in particular which is useful for protecting the coding parts of the DNA. However, as humans age, the lower levels of telomerase contribute to the degradation of telomeres causing the important part of the DNA to not be fully replicated.

In this particular article, scientists, from Harvard Medical School in Boston, engineered mice to completely lack telomerase, which causes the telomeres to run out much quicker. This results in the mice aging much faster than average, eventually resulting in age related diseases.  After allowing the engineered mice to reach adulthood, the scientists stimulate telomerase growth by feeding the mice a chemical called 4-OHT. Within the next month, the mice’s organs were restored to proper health. This also resulted in production of new neurons and supporting brain cells, allowing the reversal of the aging of the brain.

Although these organs were able to regenerate, telomerase has a negative side to it. Since telomerase is what allows DNA to be “endless,” it can often be mutated in human cancers to help tumors grow faster. If a telomere rejuvenation therapy were to occur, it is possible that it can stimulate cancer in a patient. Another possible downside of this discovery is the fact that this reverse aging occurs in accelerated aging mice and not normal aging ones. Consequently, this reveals that there could be other possible factors for aging besides short telomeres.

This article was interesting for multiple reasons. This article shows that if telomerase happens to be harnessed properly, it can be used to restore organ function to aging patients and combat age related diseases, thus allowing humans to live longer. Another reason is that it can be used to eliminate a possible contributing factor in cancer. Since telomerase can promote cancer, then there could possibly be a way to reverse the effects of a mutated telomerase. Overall, the article was intriguing and although telomerase is still being researched, it holds potential to improve the quality of life of aging humans.

http://www.nature.com/news/2010/101128/full/news.2010.635.html