A Study Of MicroRNA-138-5p Regulates Autophagy In Liver Regeneration

Objective: Viral hepatitis,liver cancer,cirrhosis and liver failure are highly prevalent in China,which seriously threaten people’s life and health.Liver resection and liver transplantation are effective means to cure many liver diseases.Therefore,improving liver function and promoting liver regeneration are significant for alleviating hepatic damage and improving patients’ prognosis.At present,there are more and more researches on miRNA and liver regeneration,but the specific mechanism has not been fully elaborated.In this study,we investigated the role and mechanism of microRNA-138-5p targeting Atg7-mediated autophagy on liver regeneration after partial hepatectomy in mice,in order to provide new ideas for liver protection in clinic.Methods: Mice were grouped by random number table method.The mice 70% partial hepatectomy models were established.qRT-PCR was used to detect the relative expression of miRNA-138-5p in residual liver tissues at different time points.AML12 cell line was routinely cultured and treated with different concentrations of HGF at 0～25 ng/μl.The relative expression of miRNA-138-5p was detected by qRT-PCR.AML12 cells and mice were treated with miR-138-5p mimics,and hepatocytes’ proliferation was detected by CCK-8 method,EdU cell proliferation assay and immunohistochemical staining.Mice were treated with miR-182-5p mimics and their controls 7 days before surgery,and the liver/body weight ratio was measured postoperatively.Western blot was used to detect the changes of LC3 expression in residual liver tissue after 70% partial hepatectomy in mice.After treatment of AML12 cells with miR-138-5p mimic,GFP-RFP-LC3 autophagy adenovirus was transfected into cells,and autophagosome formation was observed under a fluorescence microscope.Cells and mice were treated with miR-138-5p mimic and autophagy inhibitor 3-MA,respectively,and CCK-8 was used to detect changes in hepatocyte proliferation.Targetscan7.2 predicted the association of miR-138-5p with the Atg7 gene.Western blot was used to detect the expression of Atg7 in cells treated with miR-138-5p mimic or inhibitor.After hepatocytes were treated with miR-138-5p mimic and siRNA Atg7,the expression of LC3 was detected by immunofluorescence staining and the proliferation of hepatocytes was detected by EdU cell proliferation assay.Results: After HGF treatment of cells,the expression of miR-138-5p was increased and it was concentration-dependent.The expression of miR-138-5p in residual liver tissues was increased gradually with time after PH,peaked at 36 h after surgery,and then gradually decreased to normal.Overexpression of miR-138-5p promotes hepatocyte proliferation,PCNA expression and liver regeneration.The expression of LC3II/I in residual liver tissue was decreased after partial hepatectomy.Overexpression of miR-138-5p inhibited autophagy.The inhibition of autophagy can promote the effect of miR-138-5p on liver regeneration.Targetscan7.2 showed that miR-138-5p is genetically related to Atg7.Overexpression of miR-138-5p inhibited Atg7 expression in hepatocytes,while inhibition of miR-138-5p promoted Atg7 expression.Inhibition of Atg7 with Atg7 siRNA can reduce autophagy and promote hepatocytes’ proliferation.Conclusion: Partial hepatectomy can induce the expression of miR-138-5p and promote liver regeneration.miR-138-5p can inhibite hepatocyte autophagy by targeting Atg7,thus promoting hepatocyte proliferation and liver regeneration.Therefore,miR-138-5p can inhibit hepatocytes’ autophagy and promote liver regeneration after partial hepatectomy.In mouse liver regeneration,miR-138-5p can regulate autophagy by mediated Atg7,so as to reduce the damage of autophagy to liver tissue after liver partial resection,promote liver regeneration,and finally play a role in liver protection.