Sonic hedgehog promotes neurite outgrowth of cortical neurons under oxidative stress: Involving of mitochondria and energy metabolism.

Oxidative stress has been demonstrated to be involved in the etiology of several neurobiological disorders. Sonic hedgehog (Shh), a secreted glycoprotein factor, has been implicated in promoting several aspects of brain remodeling process. Mitochondria may play an important role in controlling fundamental processes in neuroplasticity. However, little evidence is available about the effect and the potential mechanism of Shh on neurite outgrowth in primary cortical neurons under oxidative stress. Here, we revealed that Shh treatment significantly increased the viability of cortical neurons in a dose-dependent manner, which was damaged by hydrogen peroxide (H2 O2 ). Shh alleviated the apoptosis rate of H2 O2 -induced neurons. Shh also increased neuritogenesis injuried by H2 O2 in primary cortical neurons. Moreover, Shh reduced the generation of reactive oxygen species (ROS), increased the activities of SOD and and decreased the productions of MDA. In addition, Shh protected mitochondrial functions, elevated the cellular ATP levels and amelioratesd the impairment of mitochondrial complex II activities of cortical neurons induced by H2 O2 . In conclusion, all these results suggest that Shh acts as a prosurvival factor playing an essential role to neurite outgrowth of cortical neuron under H2 O2 -induced oxidative stress, possibly through counteracting ROS release and preventing mitochondrial dysfunction and ATP as well as mitochondrial complex II activities against oxidative stress.