Lineage-guided senescence insights unlock precision senotherapy

In the recent study in Cell, Zhao et al. introduced a genetic toolkit enabling lineage-specific tracing, ablation, and reprogramming of senescent cells.They demonstrated that senescent macrophages aggravate while senescent endothelial cells alleviate fibrosis, laying the groundwork for precision senescence-targeting strategies.Zhao et al. developed a series of genetic toolkit-Sn-pTracer (senescent cells-pulse-chase-tracer), Sn-cTracer (senescent cells-Cre-induced-tracer), and Sn-gTracer (senescent cells-gene manipulation-tracer)-to trace, ablate, and reprogram senescent cells with high cell-type precision [1].The authors reported that senescent macrophages aggravate while senescent endothelial cells (ECs) alleviate fibrosis.These findings pave the way for precise targeted senolytic therapies.Cellular senescence, first described over six decades ago, is a stress-induced and essentially irreversible cell cycle arrest, accompanied by a distinct senescence-associated secretory phenotype (SASP) that profoundly influences tissue function and organismal aging.Senescent cells accumulate in aged or damaged tissues and exert diverse, context-dependent effects through SASP-mediated signaling.Importantly, senescence is now recognized as a double-edged sword, playing essential roles in both physiological and pathological settingspromoting tissue regeneration in certain physiological contexts while contributing to degeneration in others [2].Elucidating the mechanisms of cellular senescence and its roles in aging and disease is essential for informing the development of targeted therapeutic strategies.In particular, cell-type-specific insights into senescence offer a foundation for precision and personalized interventions.Previously used genetic models such as the p16 Ink4a -3MR [3] and INK-ATTAC [4] mice have provided valuable insights into the roles of senescent cells in aging and disease.Nevertheless, the development of cell-type-resolved senescence-targeting strategies remains largely unexplored, representing a critical gap in the field.