Intracellular H₂S production is an autophagy-dependent adaptive response to DNA damage

Hydrogen sulfide (H₂S) is a gasotransmitter with broad physiological activities, including protecting cells against stress, but little is known about the regulation of cellular H₂S homeostasis. We have performed a high-content small-molecule screen and identified genotoxic agents, including cancer chemotherapy drugs, as activators of intracellular H₂S levels. DNA damage-induced H₂S in vitro and in vivo. Mechanistically, DNA damage elevated autophagy and upregulated H₂S-generating enzyme CGL; chemical or genetic disruption of autophagy or CGL impaired H₂S induction. Importantly, exogenous H₂S partially rescued autophagy-deficient cells from genotoxic stress. Furthermore, stressors that are not primarily genotoxic (growth factor depletion and mitochondrial uncoupler FCCP) increased intracellular H₂S in an autophagy-dependent manner. Our findings highlight the role of autophagy in H₂S production and suggest that H₂S generation may be a common adaptive response to DNA damage and other stressors.