Role of miR-129-5p in regulation of epithelial-mesenchymal transition of peritoneal mesothelial cells / 中华肾脏病杂志

ABSTRACT

Objective To investigate the role of microRNA-129-5p (miR-129-5p) in the regulation of epithelial-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) isolated from peritoneal dialysate effluents and TGF-β1 induced HPMCs line.Methods The isolated cells were cultured from peritoneal dialysate effluents overnight of 10 patients just started PD and 12 patients with PD over 6 months.Taqman PCR assay was used to determine the expression of miR-129-5p in the HPMCs.Moreover,the expression of miR-129-5p in HPMCs induced by 5 μg/L TGF-β1 for 0-72 h was also detected by Taqman PCR.HPMCs were pre-transfected with miR-129-5p precursor (pre-mir-129-5p) to overexpress miR-129-5p,then incubated with TGF-β1 for 48 h,and the expression of EMT associated gene and protein was detected by real-time PCR,Western blotting and immunofluorescence,respectively.Furthermore,the effect of TGF-β1 on the expression of Smad interacting protein-1 (SIP1) and the regulation of pre-miR-129-5p on the SIP1 expression also were investigated.Results MiR-129-5p expression significantly down-regulated in the HPMCs isolated from PD patients over 6 months than from PD start patients(P ＜ 0.01).Similarly,TGF-β1 remarkably decreased miR-129-5p in HPMCs lines on time-dependent manner (P ＜ 0.01).Pre-mir-129-5p dramatically restored the expression of epithelial marker E-cadherin,while inhibited the expression of Vimentin,a mesenchymal marker,in HPMCs induced by TGF-β1 (all P ＜ 0.01).In addition,TGF-β1 increased SIP1 expression in HPMCs time dependently,while the high level of SIP1 protein was obviously repressed after transfected of pre-miR-129-5p (P ＜ 0.01),but there was no obvious change of its mRNA expression.Conclusion MiR-129-5p modulates EMT formation of HPMCs in PD process,possibly by posttranscriptional inhibition of SIP1.Targeting miR-129-5p/SIP1 may provide a new approach for the prevention and treatment of peritoneal fibrosis during PD.