Small GTP-binding protein GDP dissociation stimulator influences cisplatin-induced acute kidney injury via PERK-dependent ER stress.

Cisplatin is a common anticancer drug, but its frequent nephrotoxicity limits its clinical use. Small GTP-binding protein GDP dissociation stimulator (smgGDS), a small GTPase chaperone protein, was considerably downregulated during cisplatin-induced acute kidney injury (CDDP-AKI), especially in renal tubular epithelial cells. SmgGDS-knockdown mice was established and found that smgGDS knockdown promoted CDDP-AKI, as demonstrated by an increase in serum creatine, blood urea nitrogen levels and the appearance of tubular patterns. RNA sequencing suggested that protein kinase RNA-like ER kinase (PERK), which bridges mitochondria-associated ER membranes, was involved in smgGDS knockdown following CDDP-AKI, and then identified that smgGDS knockdown increased phosphorylated-PERK in vivo and in vitro. Furthermore, we confirmed that smgGDS deficiency aggravated apoptosis and ER stress in vivo and in vitro. And the ER stress inhibitor 4-Phenylbutyric acid and the inhibition of PERK phosphorylation mitigated smgGDS deficiency-induced ER stress related apoptosis following cisplatin treatment, while the eIF2α phosphorylation inhibitor could not reverse the smgGDS deficiency accelerated cell death. Furthermore, the over-expression of smgGDS could reverse the ER stress and apoptosis caused by CDDP. Overall, smgGDS regulated PERK-dependent ER stress and apoptosis, thereby influencing renal damage. This study identified a target for diagnosing and treating cisplatin-induced acute kidney injury.