Rheb1 deficiency elicits mitochondrial dysfunction and accelerates podocyte senescence through promoting Atp5f1c acetylation

Podocyte senescence can cause persistent podocyte injury and albuminuria in diabetic kidney disease (DKD), but the mechanism remains obscure. In this study, podocyte senescence was confirmed by immunohistochemical staining in podocytes from patients and mice with DKD. Rheb1 knockout in podocytes aggravated podocyte senescence and injury in diabetic mice, but mitigated podocyte injury in mice with podocyte-specific mTORC1 activation induced by Tsc1 deletion. In cultured podocytes, Rheb1 knockdown remarkably accelerated podocyte senescence, independent of mTORC1. Mechanistically, PDH phosphorylation in podocyte was correlated with podocyte senescence in DKD patients. Rheb1 deficiency decreased ATP, mitochondrial membrane potential and partial components of respiratory chain complex, and enhanced ROS production and PDH phosphorylation, which indicates mitochondrial dysfunction, both in vitro and in vivo. Furthermore, Rheb1 interacted with Atp5f1c, and regulated its acetylation under a high-glucose condition. Together, Rheb1 deficiency elicits mitochondrial dysfunction and accelerates podocyte senescence through promoting Atp5f1c acetylation, in an mTORC1-independent manner, which provides experimental basis for the treatment of DKD.