Impaired immune surveillance accelerates accumulation of senescent cells and aging [RNA-seq]

Cellular senescence is a stress response that imposes stable cell-cycle arrest in damaged cells, preventing their propagation in tissues. However, long-term presence of senescent cells might promote tissue degeneration and malignant transformation via secreted pro-inflammatory and matrix-remodeling factors. These factors lead to immune-cell recruitment and senescent-cell clearance. Senescent cells accumulate in tissues in advanced age. The extent of immune-system involvement in regulating age-related accumulation of senescent cells, and its consequences, are unknown. Here we show that mice with impaired cell cytotoxicity exhibit both higher senescent-cell tissue burden and chronic inflammation. They suffer from multiple age-related disorders and significantly lower survival. Strikingly, pharmacological elimination of senescent-cells by ABT-737 partially alleviates accelerated aging phenotype in these mice. In progeroid mice, impaired cell cytotoxicity further promotes senescent-cell accumulation and shortens lifespan. ABT-737 administration during the second half of life of these progeroid mice abrogates senescence signature and increases median survival. Our findings shed new light on mechanisms governing senescent-cell presence in aging, and could motivate new strategies for regenerative medicine. The experiment focused on 4 tissues: kidney, liver, lung and skin. For each tissue, we had 3 experimental groups: ABT-737 treated, Vehicle treated and Young, with at least 3 biological replicates in each.