Effect of microRNA-7 knockdown on pathology of Enterotoxin-induced murine acute lung injury / 中国免疫学杂志

ABSTRACT

Objective:To detect the effect of microRNA-7 ( miR-7 ) knockdown on pathology in murine acute lung injury ( ALI) model,and preliminarily explore its significance.Methods:Murine ALI model was performed by intraperitoneal injection of Li-popolysaccharide (LPS) (10 mg/kg) into miR-7KD mice and wild-type (wild type,WT) mice respectively.Then,the pathologic injury of lung tissue were observed by HE staining.And total cell count of bronchoalveolarlavage(BAL) was calculated.The relative expression of related cytokines in lung tissue was analyzed by Real-time PCR assay.Furthermore,the changes on proportion of innate immune cells (γδT cell and F4/80 macrophages cell) and adaptive immune cell ( CD4+T cell and CD8+T cell) were analyzed by FACS.Meanwhile, the expression of CD62L and CD69,as well as the absolute number,in CD4+T cell were also analyzed.Results: Compared with WT mice,pathological damage in lung tissues was significantly alleviated in miR-7KD mice.Real-time PCR analysis showed that the relative expression of IL-6 was obviously reduced (P<0.01),conversely,relative expression of IL-4 and TGF-βwere obviously increased (P<0.05).Furthermore,the total cell number in BAL also reduced significantly (P<0.05).Importantly,FACS analysis showed that the proportion and the absolute number of F4/80+Mφcells obviously reduced (P<0.05);however,the proportion of γδT cells increased (P<0.05).Moreover,the proportion and the absolute number of CD4+T cells and CD8+T cells were significantly reduced (P<0.05). Finally, the proportion and the absolute number of CD62L+in CD4+T cells were upregulated vigorously,contrastly,the proportion and the absolute number of CD69+in CD4+T cells were notably up-regulated (P<0.05).Conclusion:miR-7 defeciency could significantly ameliorate the pathology of murine ALI,suggesting that it may play an important regulatory role in the development of ALI.