Autophagy protects podocytes from sublytic complement induced injury

• Podocyte injury induced by sublytic C5b-9 attack is the main feature of membranous nephropathy.
• Autophagy contributes critically to the structural and functional integrity of differentiated podocytes.
• Sublytic complement attack can enhance podocyte autophagy in vitro.
• Inhibition of autophagy enhances sC5b-9-induced podocyte injury while promotion of autophagy mitigates injury.
• Autophagy can protect podocytes from sC5b-9-induced injury in vitro.

Podocyte injury induced by sublytic complement attack is the main feature of membranous nephropathy (MN). This study aimed at investigating the impact of sublytic complement attack-related autophagy on podocyte injury in vitro. Here, we show that sublytic complement attack enhances MPC5 podocyte autophagy in vitro. Inhibition of autophagy by treatment with 3-methyladenine (3-MA) significantly increased sublytic complement attack-induced changes in the injury-related morphology, stress fiber, and podocyte apoptosis, but decreased the survival and adhesion of MPC5 podocytes. In contrast, promotion of autophagy by treatment with rapamycin mitigated sublytic complement attack-induced changes in the injury-related morphology, stress fiber, and podocyte apoptosis, but increased the survival and adhesion of MPC5 podocytes. These data suggest that autophagy may protect podocytes from sublytic complement attack-induced injury in vitro.