IL-37 protects hepatocyte injury against hypoxia/reoxygenation by promoting polarization of M2-type macrophages / 复旦学报（医学版）

ABSTRACT

Objective To investigate the protective effect of IL-37 on hepatocyte injury against hypoxia/reoxygenation (H/R) by promoting polarization of M2-type macrophages and its molecular mechanisms.Methods Real-time fluorescent quantitative PCR (qRT-PCR) and Western blot were used to detect the levels of IL-37 mRNA and protein in human monocyte-macrophage THP-1 cells with different polarizations.The lentivirus with IL-37 gene was infected into THP-1 cells.The levels of CD206,CD86,ARG1 and iNOS mRNA was detected by qRT-PCR.The levels of CD163 and CD86 protein was detected by flow cytometric analysis.THP-1 cells and L02 cells were co-cultured by Transwell and treated with H/R.The survival rate and apoptotic rate of L02 cells were detected.The levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) in culture medium were measured.The levels of STAT6 and its phosphorylation in THP-1 cells were detected by Western blot.Results The levels of IL-37 mRNA and protein were up-regulated in M2-type macrophages.IL-37 promoted the polarization of M2-type macropahges.M2-type macrophages induced by IL-37 were cocultured with L02 cells,the survival rate was significantly increased by H/R treatment (P =0.015),while the apoptotic rate,ALT level and AST level were significantly decreased (P＜0.001).The level of phosphorylated STAT6 in THP-1 cells overexpressing IL-37 was up-regulated (P ＜ 0.01).Conclusions IL-37 can induce polarization of M2-type macrophages and protect hepatocyte injury against H/R.Its mechanism may be related to STAT6 signal pathways.