Selective EZH2 inhibitor zld1039 alleviates inflammation in cisplatin-induced acute kidney injury partially by enhancing RKIP and suppressing NF-κB p65 pathway

Enhancer of zeste homolog 2 (EZH2), a component of polycomb repressive complex 2 (PRC2), is a histone lysine methyltransferase mediating trimethylation of histone H3 at lysine 27 (H3K27me3), which is a repressive marker at the transcriptional level. EZH2 sustains normal renal function and its overexpression has bad properties. Inhibition of EZH2 overexpression exerts protective effect against acute kidney injury (AKI). A small-molecule compound zld1039 has been developed as an efficient and selective EZH2 inhibitor. In this study, we evaluated the efficacy of zld1039 in the treatment of cisplatin-induced AKI in mice. Before injection of cisplatin (20 mg/kg, i.p.), mice were administered zld1039 (100, 200 mg/kg, i.g.) once, then in the following 3 days. We found that cisplatin-treated mice displayed serious AKI symptoms, evidenced by kidney dysfunction and kidney histological injury, accompanied by EZH2 upregulation in the nucleus of renal tubular epithelial cells. Administration of zld1039 dose-dependently alleviated renal dysfunction as well as the histological injury, inflammation and cell apoptosis in cisplatin-treated mice. We revealed that zld1039 administration exerted an anti-inflammatory effect in kidney of cisplatin-treated mice via H3K27me3 inhibition, raf kinase inhibitor protein (RKIP) upregulation and NF-κB p65 repression. In the cisplatin-treated mouse renal tubular epithelial (TCMK-1) cells, silencing of RKIP with siRNA did not abolish the anti-inflammatory effect of EZH2 inhibition, suggesting that RKIP was partially involved in the anti-inflammatory effect of zld1039. Collectively, EZH2 inhibition alleviates inflammation in cisplatin-induced mouse AKI via upregulating RKIP and blocking NF-κB p65 signaling in cisplatin-induced AKI. The potent and selective EZH2 inhibitor zld1039 has the potential as a promising agent for the treatment of AKI.