β-Hydroxybutyrate, a ketone body, reduces the cytotoxic effect of cisplatin via activation of HDAC5 in human renal cortical epithelial cells

β-Hydroxybutyrate (βOHB) is a metabolic intermediate that constitutes about 70% of ketone bodies produced in liver from oxidation of fatty acids released from adipose tissue. A recent study showed that βOHB inhibits HDAC1, 3 and 4 (classes I and IIa) in human embryonic kidney 293 (HEK293) cells. Therefore, βOHB could regulate epigenetics via modulating HDACs. However, little is known about the protective effect of βOHB on renal cells through epigenetics. The aim of this study is to investigate whether βOHB reduces cisplatin-induced nephrotoxicity in human renal cortical epithelial (HRCE) cells by modulating HDACs. In this study, we used human renal cortical epithelial (HRCE) cells. The anti-apoptotic effect of βOHB was evaluated using flow cytometry analysis. The expression of apoptosis-related proteins and HDACs was evaluated by western immunoblot. The results showed that βOHB significantly reduced cisplatin-induced apoptosis in HRCE cells. Furthermore, βOHB significantly reduced cisplatin-induced cleavage of caspase-3, acetylation of histone H3, and phosphorylation of AMP-activated kinase. This anti-apoptotic effect of βOHB was markedly attenuated by an inhibitor of HDAC4/5, and βOHB-mediated suppression of cleavage of caspase3 was significantly blocked by siRNA-induced gene silencing of HDAC5. βOHB attenuates cisplatin-induced apoptosis by activation of HDAC5 in HRCE cells, suggesting that βOHB may be a new therapeutic agent for cisplatin nephropathy.