Epithelial–mesenchymal transition of rat peritoneal mesothelial cells via Rhoa/Rock pathway

Abstract

The objective of this study was to investigate the role of the RhoA/Rock signaling pathway in the epithelial-mesenchymal transition (EMT) of rat peritoneal mesothelial cells (RPMCs). Primary SD rat peritoneal mesothelial cells were cultured in vitro. RPMCs were randomly assigned to four groups: group A (control), group B (TGF-β1, 10 μg/L), group C (10 μg/L TGF-β1 + 10 μmol/L Y-27632, an inhibitor of Rock that was pre-applied for 2 h before TGF-β1 stimulation), and group D (Y-27632 alone, 10 μmol/L). Our results were as follows: (1) TGF-β1 stimulation elicited a robust increase in RhoA activity in a time-dependent manner; the increase was 2.57 ± 0.52 times larger than the activity observed for the control group (P < 0.05) after 10 min of stimulation. RhoA activity peaked at 1 h and was 4.35 ± 0.41 times the value observed for the control group (P < 0.05). (2) TGF-β1 up-regulated mRNA and/or protein expression of α-SMA, vimentin, and collagen and down-regulated mRNA and protein expression of E-cadherin in RPMCs. (3) The Rock inhibitor Y-27632 effectively reduced TGF-β1-induced expression of α-SMA, collagen, and vimentin; the mRNA levels of α-SMA and collagen decreased by 53.8% and 55.7%, respectively, and the protein levels of α-SMA, vimentin, and collagen decreased by 42.6%, 60.1%, and 58.1%, respectively, as compared to TGF-β1-stimulated groups (P < 0.05). However, the Rock inhibitor Y-27632 had no effect on the level of E-cadherin. In conclusion, the RhoA/Rock signaling pathway may mediate EMT induced by TGF-β1 in rat peritoneal mesothelial cells. The RhoA/Rock pathway may be a potential therapeutic target for the treatment of peritoneal fibrosis.

Hypoxia promotes dissemination of multiple myeloma through acquisition of epithelial to mesenchymal transition-like features

“…43,47 Similarly, activation of downstream effectors of CXCR4, including Rho-GTPases, was observed during EMT and promoted cell movement and migration. [48][49][50] We have shown previously that downstream effectors of CXCR4, RhoGTPases, were up-regulated in MM compared with normal plasma cells and play key roles in the movement, migration, and homing of MM cells to the BM. 7 In addition to the findings that circulating MM cells displayed hypoxic MM features, such as decreased expression of E-cadherin and increased expression of CXCR4, we investigated the role of exposure to a normoxic environment on the behavior of hypoxic cells.…”

1,25-(OH)2D3 and its analogue BXL-628 inhibit high glucose-induced activation of RhoA/ROCK pathway in HK-2 cells

“…Previous studies have demonstrated that RhoA and its downstream kinase Rho-kinase (ROCK) are able to mediate matrix elaboration via mesangial cells (MCs) in hyperglycemic and DN conditions (4,11), and the RhoA/ROCK signaling pathway has been demonstrated to be associated with fibrosis progression in multiple organs including the kidneys, liver and lungs (4,9,12). Furthermore, RhoA/ROCK was previously reported to be associated with EMT (7,13), which was prevented by inhibition of RhoA activation in rat peritoneal cells (13). A previous study by the present authors also revealed that transforming growth factor (TGF)-β1-mediated RhoA/ROCK activation contributed to the dissolution of tight junctions during EMT in HK-2 cell in vitro (14).…”

TGF-β1 induces the dissolution of tight junctions in human renal proximal tubular cells: Role of the RhoA/ROCK signaling pathway

“…It has been confirmed that RhoA is activated by TGF-β1 and is part of an important signaling pathway in TGF-β1-induced EMT (11,12). ROCK is a characteristic, downstream protein in the Rho signaling pathway and an important kinase involved in the regulation of cell movement and cytoskeletal organization (19)(20)(21).…”

“…Our previous study revealed that TGF-β1 induced the downregulation of vimentin (a cytoskeletal protein) and the upregulation of α-SMA via the RhoA/ROCK signaling pathway in RPMCs (12). Other stueis, however, have shown that the Rho/ROCK signaling pathway may also mediate the downregulation of claudin-4, which is a component of TJs in corneal, gastric epithelial and Madin-Darby canine kidney epithelial cells (26)(27)(28), indicating that the Rho/ROCK signaling pathway may play a role in the dissolution of TJs.…”

“…Tian et al (11) provided evidence of the function of TGF-β1-induced RhoA activation in renal proximal tubular epithelial cells. Our previous study suggested that the RhoA/ROCK signaling pathway mediates TGF-β1-induced EMT in rat peritoneal mesothelial cells (RPMCs) (12), and the changes characteristic of EMT were partially reversed by Y-27632, a ROCK inhibitor. In another previous study, we suggested that the Smad signaling pathway mediates TGF-β1-induced EMT in human peritoneal mesothelial cells (HPMCs) (13).…”