β-Hydroxybutyrate against Cisplatin-Induced acute kidney injury via inhibiting NLRP3 inflammasome and oxidative stress

Cisplatin, as a commonly used anticancer drug, can easily lead to acute kidney injury (AKI), and has received more and more attention in clinical practice. β-hydroxybutyric acid (BHB) is a metabolite in the body and acts as an inhibitor of oxidative stress and NLRP3 inflammasome, reducing inflammatory responses and apoptosis. However, the role of BHB in cisplatin-induced AKI is currently not fully elucidated. In this study, C57BL/6 male mice were randomly divided into normal control group, cisplatin-induced AKI group and AKI with BHB treatment group. Compared to the control, cisplatin-treated mice exhibited high level of serum creatinine, blood urea nitrogen and severe tubular injury, which accompanied with significantly increased expression level of NLRP3, IL-1β, IL-18, BAX, cleaved-caspase 3, as well as aggravated oxidative stress and renal tubular cell apoptosis. However, these changes were significantly improved in that of BHB treatment. In vitro, our study showed that the expression of cleaved-caspase3, IL-1β and IL-18 were significantly increased in human proximal tubular epithelial cell line (HK-2) treated with cisplatin compared with the control group, while decreased in cells treated with BHB. Furthermore, a significantly increased expression of cGAS and STING in HK-2 cells treated with cisplatin were found, whereas notably decreased in cells treated with BHB. This data indicates that BHB protects against cisplatin-induced AKI and renal tubular damage mediated by NLRP3 inflammasome and cGAS-STING pathway.