Mir-24 regulates hepatocyte apoptosis via BIM during acute liver failure.

Acuteliver failure (ALF) has a high mortality rate and is characterized by massive hepatocyte destruction. Although microRNAs (miRNAs) play an important role in manyliver diseases, the role of miRNAs in ALF development is unknown. In this study, the murine ALF model was induced by intraperitoneal injection of D-galactosamine/lipopolysaccharide (D-GalN/LPS). Compared with saline-treated mice, miR-24 was distinctly down-regulated post D-GalN/LPS challenge in vivo and D-galactosamine/tumor necrosis factor (D-GalN/TNF) challenge in vitro , which was confirmed by quantitative real-time polymerase chain reaction. Meanwhile, the mRNA and protein levels of the BH3-only-domain-containing protein BIM were upregulated after challenge both in vivo and in vitro . Previous studies have demonstrated that hepatocyte apoptosis is a distinguishing feature of D-GalN/LPS-associated liver failure. In this study, D-GalN/LPS-challenged mice showed higher alanine aminotransferase and aspartate aminotransferase levels, more severe liver damage, increased numbers of apoptotic hepatocytes and higher levels of caspase-3 compared with saline-treated mice. In D-GalN/TNF-treated BNLCL2 cells, miR-24 overexpression attenuated apoptosis.Furthermore, miR-24 overexpression reduced BIM mRNA and protein levels in vitro . Taken together, these findings demonstrate that miR-24 regulates hepatocyte apoptosis via BIM during ALF development, suggesting that miR-24 is a novel onco-miRNA that may provide potential therapeutic targets for ALF.