Figure 1.

Graphic summary of the dual role, anti-oxidant or pro-oxidant, of G6PD in embryogenesis. Panel A: Under high oxidative stress conditions (supra-physiological), G6PD acts as a key anti-oxidative enzyme by eliminating ROS (O₂^-, H₂O₂ or OH^-) via production of NADPH and regeneration of GSH. This mechanism prevents embryonic cells in animal models from undergoing apoptosis, mitochondria dysfunction and embryonic lethality in animal models. Panel B: G6PD can act as a pro-oxidant in low oxidative stress conditions (eustress) by providing NADPH for NOX/NOS in producing ROS or RNS, which are required for ESCs proliferation, differentiation and migration.