Figure 3.

Signaling of mtROS. At low levels, mtROS participate in the process of hypoxia adaptation by regulating the stability of hypoxia-inducible factor 1α (HIF-1α); moderate levels of mtROS are involved in regulating the production of proinflammatory cytokines by directly activating the inflammasome and mitogen-activated protein kinase (MAPK); high levels of mtROS are capable of inducing apoptosis and autophagy by oxidation of the mitochondrial pores and autophagy-specific gene 4 (ATG4) respectively.