MiR-27a-5p regulates apoptosis of liver ischemia-reperfusion injury in mice by targeting Bach1.

Ischemia-reperfusion (I/R) injury causes cellular dysfunction and a series of immune or apoptotic reactions. Bach1 is a mammalian transcription factor that represses Hmox1, which encodes heme oxygenase-1 (HO-1) that can degrade heme into free iron, carbon monoxide, and biliverdin, to play an important role in antioxidant, anti-inflammatory, and antiapoptotic activities. MicroRNAs (miRNAs) can be found in a variety of eukaryotic cells and viruses, a class of noncoding small RNAs that are encoded by endogenous genes. The aims of this study were to determine whether miR-27a-5p targets Bach1 and regulates cellular death; the dual-luciferase reporter assay was used to detect this and the results showed that miR-27a-5p significantly decreased the luciferase activity of the Bach1 3'-untranslated region. MiR-27a-5p was increased in mice during hepatic I/R and Bach1 was decreased. By transfecting the AML12 cells with the mimic, inhibitor miR-27a-5p in hypoxia/reoxygenation (H/R) models showed that overexpression of miR-27a-5p decreased Bach1 messenger RNA, upregulated HO-1 expression, and promoted antiapoptotic Bcl-2 and downregulated proapoptotic caspase-3 gene expression. In contrast, the miR-27a-5p inhibitor yielded the opposite results. Meanwhile, transfection with Bach1 small interference RNA obviously upregulated the protein levels of HO-1 and resulted in an increase in Bcl-2 and a decrease in caspase-3 protein levels. Thus, we can conclude that miR-27a-5p is relevant to liver I/R injury and overexpression of miR-27a-5p may alleviate apoptosis in H/R injury by targeting Bach1 in vitro.