Berberine alleviates cisplatin-induced acute kidney injury by regulating mitophagy via PINK 1/Parkin pathway

Background To study the protective effect of berberine (BBR) on cisplatin-induced acute kidney injury (AKI) and its effect on mitophagy. Methods (I) Male C57BL/6 mice aged 6-8 weeks were randomly divided into control group (saline), cisplatin group (cisplatin), and cisplatin + BBR (5, 10 mg/kg) groups. In the cisplatin group and BBR groups, mice were injected intraperitoneally with 15 mg/kg of cisplatin. Mice in BBR groups were given BBR at 72, 48, 24, 0.5 h before and 24, 48 h after cisplatin injection. Mice were sacrificed 72 h after cisplatin injection, and blood were collected for detecting serum creatinine (SCr) and blood urea nitrogen (BUN) levels. Kidneys were collected for detecting protein expression levels of Kidney injury molecule 1 (KIM-1), LC3 II/LC3 I, p62, PINK 1, Parkin in the renal tissue by Western blotting. The pathological changes in renal tissues were observed using periodic acid-Schiff (PAS) staining. (II) Renal tubular epithelial cells (RTECs) were pretreated with different concentrations (1, 2, and 4 µM) of BBR, and then incubated with cisplatin. Changes in autophagy proteins LC3 II/LC3 I, p62, PINK 1, and Parkin were detected by Western blotting, and changes in cellular reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected by flow cytometry. Results (I) Mice treated with BBR at dosage of 5 and 10 mg/kg for 6 days showed significant reduction in SCr and BUN compared to that in mice treated with cisplatin. PAS staining and immunohistochemistry showed that BBR ameliorated cisplatin-induced nephrotoxicity and reduced cisplatin-induced increase in protein expression levels of KIM-1. Compared to cisplatin-treated mice, the mice treated with BBR showed increased LC3 II/LC3 I, PINK 1, and Parkin, and decreased p62 protein expression. (II) Compared to cisplatin-incubated RTECs, cells pretreated with BBR for 24 h exhibited increased protein expressions of LC3 II/LC3 I, PINK1, and Parkin and decreased protein expression of p62. BBR reversed cellular ROS and cell MMP level induced by cisplatin. Conclusions BBR plays a protective role in cisplatin-induced AKI by up-regulating mitophagy in RTECs.