In adult stem cells, the low activity of telomerase contributes to telomere shortening, which leads to replicative senescence and tissue dysfunction, significant factors in the aging process.

The article also addresses the challenges associated with non-canonical functions of telomerase and telomere-independent aging, suggesting that inducible telomerase systems and pharmacological activators could improve the safety of telomerase-related therapies.

The article delves into the critical role of telomerase, particularly the telomerase reverse transcriptase (TERT), in stem cell biology, focusing on its impact on cellular aging and regenerative capabilities.

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) exhibit high levels of telomerase activity, which is essential for maintaining telomere length; however, this activity diminishes as cells undergo differentiation.

iPSCs present a viable alternative to embryonic stem cells by circumventing ethical concerns, and they can reactivate telomerase during the reprogramming process, thus offering similar regenerative properties, albeit with risks such as teratoma formation.

The reactivation of telomerase in stem cells has demonstrated potential to rejuvenate these cells, enhancing their proliferation and effectiveness in tissue repair, although this raises concerns regarding an increased risk of cancer.