Tissue specificity of senescent cell accumulation during physiologic and accelerated aging of mice.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model study
PubMed 31981461 · doi:10.1111/acel.13094
What was done
Researchers measured markers of cellular senescence (p16^Ink4a and p21^Cip1 mRNA, senescence-associated β-galactosidase activity, p21^Cip1 protein, and Lamin B1 mRNA and protein) across 13 tissues in 4- to 5-month-old DNA repair-deficient mice (Ercc1^-/∆) and 2.5-year-old wild-type (WT) mice. They also tracked in vivo senescence progression using a p16^Ink4a luciferase reporter system in Ercc1^-/Δ mice.
What was found
p16^Ink4a and p21^Cip1 mRNA rose ~15-fold in peripheral lymphocytes of both 4- to 5-month-old Ercc1^-/∆ mice and 2.5-year-old WT mice. The same 10 of 13 tissues exhibited elevated p16^Ink4a and p21^Cip1 mRNA, increased senescence-associated β-galactosidase activity, increased p21^Cip1 protein, and decreased Lamin B1 expression in both models. Luciferase activity increased progressively with age, particularly in lung, thymus, and pancreas, with higher senescence levels observed in male mice until late life.
Why it matters
The findings demonstrate that Ercc1-deficient mice mimic the tissue-level distribution of senescent cell accumulation seen during natural chronological aging, accelerating the process approximately sixfold.
Limits
The study is restricted to mouse models, and translation to human tissue aging is not directly tested. The abstract does not provide the total number of animals (n) or exact quantitative effect sizes for each individual tissue.
Cited by
- supports In genetically identical mice housed in identical environments, senescent cell burden measured via in vivo luciferase luminescence shows increasing stochastic variation with age.