Atypical NF-?B activation by endogenous DNA damage drives senescence and aging
Chronic activation of NF-?B contributes to senescence and aging, but how endogenous DNA damage engages this pathway in vivo remains unclear. NF-?B can be activated by an atypical pathway in which genotoxic stress triggers ATM-dependent sumoylation of the regulatory subunit NEMO, yet the role of this axis in senescence and aging has not been tested. Here we introduced a knock-in NEMO double-lysine mutant (NEMO-DK) that prevents sumoylation at the conserved sites required for DNA damage-induced NF-?B activation, and examined its impact in Ercc1-/? mice, a model of accelerated, DNA damage-driven aging. We demonstrated that NEMO-DK markedly reduced senescence and SASP in primary fibroblasts and across multiple tissues, improved liver and skeletal muscle pathology, attenuated intervertebral disc degeneration, significantly delayed the onset and progression of aging symptoms and extended healthspan. These findings identify DNA damage-induced NEMO sumoylation as a key driver of NF-?B-mediated senescence in vivo and suggest that the atypical NF-?B pathway is a potential therapeutic target to mitigate aging-associated diseases. Overall design: RNA was extracted from livers of female mice who were between 11-15 weeks old using Trizol reagent (Thermo Fisher, USA). Four independent biological replicates for WT, and two for NemoDK;Ercc1-/? and Ercc1-/? each were analyzed.