NADPH oxidase 1, NADPH oxidase 2, NADPH oxidase 4 (NOX1, NOX2, NOX4)

NADPH oxidases (NOX) are a family of membrane-bound, electron-transferring enzymes whose primary function is the generation of reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, through the transfer of electrons from NADPH to molecular oxygen[2][3][4]. NOX1, NOX2, and NOX4 are the most studied human isoforms; NOX1 is found predominantly in the colon and vascular cells, NOX2 in phagocytes and endothelial cells, and NOX4 more widely in the vasculature, kidney, and other tissues[3][5]. NOX2 requires assembly with several cytosolic subunits (including p47phox, p67phox, Rac) for activation, while NOX1 and NOX4 depend primarily on membrane partners (e.g., p22phox), with NOX4 being constitutively active[1][3][4]. These enzymes play critical roles in physiology and disease by regulating redox signaling, cell growth, and host defense. Dysregulation or overactivation of NOX enzymes contributes to pathologies such as cardiovascular disease, inflammation, diabetes, fibrosis, certain cancers, and neurodegeneration[5][3][4]. Pharmacological inhibitors have been developed to target specific NOX isoforms, aiming to reduce inappropriate oxidative stress while minimizing impacts on beneficial ROS signaling and immune defense[4].

Other names

NADPH oxidase 1gp91^phox^NADPH oxidase 2CYBBNADPH oxidase 4

Inhibition of ROS production by direct enzyme inhibition (e.g., setanaxib for NOX1/NOX4). Reduction of oxidative signaling and tissue injury.