ABSTRACT
Objective To find the key miRNA that relative to peritoneal fibrosis associated with peritoneal dialysis (PD) by microarray technology,and verify its expression in vitro and in vivo.Methods The peritoneal fibrosis mouse model associated with PD were established by intraperitoneal injection of lipopolysaccharide (LPS)+ 4.25％ peritoneal dialysate.The expression of miRNA was detected by microarray in peritoneal tissues.The expression of miRNA profiles between fibrotic and normal peritoneal tissues was compared.The differentially expressed miRNA (miR-200a) was validated by real-time PCR in lager sample size cohorts.The expressions of miR-200a were also detected in the epithelial-mesenchymal transition (EMT) process of human peritoneal mesothelium cells.Results In mice model of PD,peritoneal tissue was markedly thickened and with a massive extracellular matrix accumulation.In contrast with control,the expression level of epithelial marker E-cadherin was significantly decreased,α-SMA,Col-Ⅰ and FN were remarkably increased (P ＜ 0.05).By miRNA microarray analysis,miR-200a was significantly down-regulated (3.31 folds change,P ＜ 0.05) in fibrotic peritoneal tissues.The down-regulated expression level of miR-200a was also validated by realtime PCR in larger cohorts (P ＜ 0.05).Then,the expression level of miR-200a was detected in the EMT process of human peritoneal mesothelium cells.During the process of TGF-β1 induced EMT,miR -200a was significantly down-regulated compared with the control (P ＜ 0.05).Conclusions Downregulated expression of miR-200a was observed both during peritoneal fibrosis and TGF-β 1 induced EMT in vivo and in vitro,suggesting that miR-200a may be involved in the peritoneum fibrosis by regulating the target genes of EMT.