Epigenetic ageing is distinct from senescence-mediated ageing and is not prevented by telomerase expression.
Level 5 - mechanism / opinion, no new human data
In vitro bench research using cell cultures
PubMed 30332397 · doi:10.18632/aging.101588
What was done
Researchers measured epigenetic age using DNA methylation-based estimators in human cell cultures across multiple cell types and donors. They examined the relationship between epigenetic aging and telomerase activity by expressing wild-type hTERT and hTERT mutants to assess the effects of cellular immortalization, telomere synthesis, and lifespan extension on epigenetic aging rates.
What was found
The abstract reports no numerical values or statistical metrics. Experimentally, hTERT expression did not induce perceptible changes in the rate of epigenetic aging, and cells bypassing senescence continued to age epigenetically. Using hTERT mutants, neither telomere synthesis nor immortalization was required for ongoing epigenetic aging; extending cellular lifespan alone was sufficient to support continued epigenetic aging.
Why it matters
The findings show that epigenetic aging is mechanistically distinct from replicative senescence. Strategies focused solely on telomerase reactivation may prevent replicative senescence but are unlikely to halt DNA methylation-based aging.
Limits
The study is restricted to in vitro cell models, limiting direct translation to in vivo organismal aging. The abstract does not provide numerical data, statistical values, or the exact sample sizes (number of donors and cell types).
Cited by
- supports Immortalizing a cell by overexpressing TERT (telomerase reverse transcriptase) does not stop epigenetic aging, and its epigenetic age continues to increase with passaging.