Ageing is an inevitable process. Every time a cell divides, it loses a bit of its genetic constituent at the terminal position of chromosomes, called telomere shortening . This phenomenon is more or less primarily responsible for senescence or cell death . However, at embryonic stages or even after that, some cells like male germ cells, activated lymphocytes, or stem cells live longer than other cell types due to prolonged activity of enzyme telomerase . In humans, the hTERT gene encodes for telomerase enzyme which protects the chromosomal terminals from degradation. Unfortunately, it is only active up to a certain cellular age or in cellular types and becomes almost inert in diploid somatic cells. Although Its exact mechanism and causes are unknown, strategies are being employed to keep the hTERT gene active in every cell type. Telomerase's have a profound impact on genetic integrity as well as on senescence. For example, the ectopic expression of this gene has resulted in the increased life span in a study .
A substantial scientific establishment is involved in this field and trying to improve cellular longevity as much as they can. However, increasing life span has its own pros and cons, for example; almost every cell can lead to a cancerous cell line if its native mechanisms get disturbed etc.
So, here I just want to start a discussion on different hurdles in increasing cellular life span and its major drawbacks in terms of telomerase reactivation. With this, I hope, soon the ageing would not remain an inevitable process.
Jiang, H., Ju, Z. and Rudolph, K.L., 2007. Telomere shortening and ageing. Zeitschrift für Gerontologie und Geriatrie, 40(5), pp.314-324.
Zhang, X., Mar, V., Zhou, W., Harrington, L. and Robinson, M.O., 1999. Telomere shortening and apoptosis in telomerase-inhibited human tumor cells. Genes & development, 13(18), pp.2388-2399.
Cong, Y.S., Wright, W.E. and Shay, J.W., 2002. Human telomerase and its regulation. Microbiology and molecular biology reviews, 66(3), pp.407-425.
Mendelsohn, A.R. and Larrick, J.W., 2012. Ectopic expression of telomerase safely increases health span and life span. Rejuvenation research, 15(4), pp.435-438.