Madrid, Spain -
Shortening of telomeres is associated with cellular senescence. However, the shortening of telomeres is known to be associated not just with cell death but also dysfunction. For example, associations have been previously made between hypertension and telomere shortening (Fuster et al. Telomere dysfunction in hypertension. J Hypertens. 2007 Nov;25(11):2185-2192).
In a recent paper (Siegl-Cachedenier et al. Telomerase reverses epidermal hair follicle stem cell defects and loss of long-term survival associated with critically short telomeres. J Cell Biol. 2007 Oct 22;179(2):277-90) the relevance of telomere length on activity of epidermal stem cells was assessed.
The authors showed that shortness of telomeres is associated with inhibited mobilization of epidermal stem cells out of the hair follicle niche. Furthermore, inducing expression of telomerase in a murine model of short telomeres is able to overcome epidermal hair follicle migration.
These data suggest that telomerase may have other activities in addition to preventing cellular apoptosis.