NADPH oxidase contributes directly to oxidative stress and apoptosis in nerve growth factor-deprived sympathetic neurons.

Reactive oxygen species (ROS) are necessary for programmed cell death (PCD) in neurons, but the underlying ROS-producing enzymes have not been identified. NADPH oxidase produces ROS, although the expression of its five subunits are thought to be restricted largely to non-neuronal cells. Here, we show that NADPH oxidase subunits are present in neurons. Moreover, both an NADPH oxidase inhibitor, diphenyleneiodonium, and NAPDH oxidase genetic deficiency inhibit apoptosis in a classic model of PCD, i.e., NGF-deprived sympathetic neurons. Overall, these results indicate that NADPH oxidase is unexpectedly present in neurons and can contribute to neuronal apoptosis.