SIRT2 is involved in cisplatin-induced acute kidney injury through regulation of mitogen-Activated protein kinase phosphatase-1

Background. Activation of mitogen-Activated protein kinase phosphatase-1 (MKP-1), a dual-specificity protein phosphatase, regulates mitogen-Activated protein kinase signaling. C-Jun Nterminal kinase (JNK) and p38 are activated in cisplatininduced renal injury. However, the change of MKP-1 expression in cisplatin-induced renal injury and the regulatory effect of sirtuin 2 (SIRT2), a nicotinamide adenine dinucleotide dependent deacetylase, onMKP-1 remains unknown. Methods. To address these issues, we used constitutional Sirt2 knockout (KO) mice, transgenic (TG) mice with increased expression of SIRT2 specifically in proximal tubular epithelial cellsand wild-Type (WT) mice. Cisplatin nephrotoxicity was induced by intraperitoneal injection of cisplatin. Results. MKP-1 expression in the kidney was decreased after cisplatin treatment. Cisplatin-induced downregulation ofMKP-1 was reversed in Sirt2 KO mice kidney and further decreased in Sirt2 TG mice kidney. We observed similar phenomenon with SIRT2-knockdown or SIRT2-overexpressed tubular epithelial cells. Phosphorylation of p38 and JNK, a downstream signal pathway ofMKP-1, increased in WT mice kidney following treatment with cisplatin. A decrease in SIRT2 suppressed cisplatin-induced phosphorylation of p38 and JNK in kidney and tubular epithelial cells. Overexpression of SIRT2 further increased phosphorylation of p38 and JNK in kidney and tubular epithelial cells. Acetylation of MKP-1 was significantly increased in SIRT2-knockdown cells and decreased in SIRT2-overexpressed cells after cisplatin stimulation. Sirt2 KO mice and Sirt2 TG mice showed amelioration and aggravation of renal injury, apoptosis, necroptosis and inflammation induced by cisplatin. Conclusion. Our data show that SIRT2 is associated with cisplatin-induced renal injury through regulation of MKP-1 expression.