LncRNA Gm4419 induces cell apoptosis in hepatic ischemia–reperfusion injury via regulating the miR-455–SOX6 axis

Long non-coding RNA (lncRNA) is known to be involved in a variety of diseases. However, the role of Gm4419 in hepatic ischemia–reperfusion (I/R) injury remains unknown. To study this, we first established a rat model of hepatic I/R, and a BRL-3A cell model of hypoxia–reoxygenation (H/R) for in vivo and in vitro studies. Staining with hematoxylin and eosin and hepatic injury scores were used to evaluate the degree of hepatic I/R injury. Cell apoptosis was assessed via staining with Edu, and with annexin V–FITC–propidium iodide assays. The interactions between Gm4419 and miR-455, as well as miR-455 and SOX6 were evaluated via luciferase reporter activity assays and RNA immunoprecipitation assays. In vivo, we found that Gm4419 was up-regulated in the rats subjected to I/R. Moreover, knockdown of Gm4419 alleviated the I/R-induced liver damage in the rats. In vitro, knockdown of Gm4419 alleviated H/R-induced apoptosis in BRL-3A cells. Interestingly, we found that miR-455 is a target of Gm4419, and Gm4419 regulates the expression of miR-455 via sponging. Furthermore, SOX6 was proven to be the target of miR-455. Finally, rescue experiments confirmed that knockdown of Gm4419 inhibits apoptosis by regulating miR-455 and SOX6 in H/R-treated BRL-3A cells. Therefore, our findings show that the lncRNA Gm4419 accelerates hepatic I/R injury by targeting the miR-455–SOX6 axis, which suggests a novel therapeutic target for hepatic I/R injury.