Mechanisms of human umbilical cord mesenchymal stem cells-derived exosomal lncRNA GAS5 in alleviating EMT of HPMCs via Wnt/β-catenin signaling pathway

Abstract

Abstract The aim of this study was to reveal mechanisms of exosomal lncRNA GAS5 derived from human umbilical cord mesenchymal stem cells (hUC-MSCs) on epithelial-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs) under high glucose (HG) conditions. HPMCs were stimulated with 2.5% glucose. The effects on EMT of HPMCs were observed by using an hUC-MSC conditioned medium (hUC-MSC-CM) and extracted exosomes. Four groups were established: ① control group,②HG group (2.5% glucose), ③conditioned medium (CM) group (2.5% glucose and 7.5% MSC-CM), and ④ exosome group (2.5% glucose and exosomes extracted from 7.5% MSC-CM), all treated for 48 h. After hUC-MSCs were transfected with GAS5 siRNA, exosomes were extracted to act on HPMCs. Western blot assay and real-time PCR were used to detect expressions of EMT markers, PTEN and Wnt/β-catenin pathway in HPMCs. Based on the real-time PCR, the changes in levels of expression of lncRNA GAS5 and miR-21 were detected. We found that HG could induce the EMT of HPMCs. Compared with the HG group, the hUC-MSC-CM could alleviate EMT of HPMCs induced by HG through exosomes. Exosomes in the hUC-MSC-CM entered HPMCs, by transferring lncRNA GAS5 to HPMCs, which down-regulates miR-21 and up-regulates PTEN, thus finally alleviating EMT of HPMCs. Wnt/β-catenin pathway plays an essential role in alleviating EMT of HPMCs by exosomes in the hUC-MSC-CM. By transferring lncRNA GAS5 to HPMCs, exosomes derived from hUC-MSCs may competitively bind to miR-21 to regulate suppression on target PTEN genes and alleviate EMT of HPMCs through Wnt/β-catenin pathway.