Angiotensin II induces reorganization of the actin cytoskeleton and myosin light-chain phosphorylation in podocytes through rho/ROCK-signaling pathway
RENAL FAILURE
Authors: Wang, Siyuan; Chen, Cheng; Su, Ke; Zha, Dongqing; Liang, Wei; Hillebrands, J. L.; van Goor, Harry; Ding, Guohua
Abstract
Aims In the present study, we have evaluated the effect of angiotensin II (Ang II) on actin cytoskeleton reorganization and myosin light-chain (MLC) phosphorylation in podocytes to demonstrate whether the Rho/Rho-associated coiled kinase (ROCK) pathway is involved podocyte injury. Methods Eighteen male Sprague-Dawley rats were divided into three groups and treated with Ang II, saline or telmisartan. Morphological changes were studied at 28 days after treatment. Immunohistochemistry and Western blotting were used to determine the renal expression of p-MLC and ROCK2. Cultured podocytes were treated with Ang II (10(-7) M) with or without Rhokinase inhibitor (Y27632, 10(-6) M) for variable time periods. F-actin was visualized with fluorescein isothiocyanate (FITC)-conjugated phalloidin or tetraethyl rhodamine isothiocyanate (TRITC)-conjugated phalloidin. p-MLC expression was evaluated by immunofluorescence and Western blot. The activation of Rho/ROCK was evaluated by Western blot. Results The expression of p-MLC in glomeruli increased significantly in rats treated with Ang II when compared to the control rats as shown by Western blot (p<0.05). In cultured podocytes, Rho A and ROCK2 increased after incubation with Ang II. Ang II increased the expression of ROCK2, which was accompanied with altered morphology, redistribution of actin and increased phosphorylation of MLC. The distribution of actin changed to a large extent, although overall quantitative differences were not observed. Addition of Y-27632 to podocytes treated with Ang II could ameliorate F-actin cytoskeleton remodeling and the increment in p-MLC expression. Conclusion Ang II-induced podocyte cytoskeleton protein expression changing through the RhoA/ROCK2 p-MLC/F-actin pathway.
Y-27632, a Rho-associated protein kinase inhibitor, inhibits systemic lupus erythematosus
BIOMEDICINE & PHARMACOTHERAPY
Authors: Wang, Yuanyuan; Lu, Yang; Chai, Jixia; Sun, Meiqun; Hu, Xiaodong; He, Wenxin; Ge, Min; Xie, Changhao
Abstract
The purpose of the present study was to evaluate whether Rho-kinase inhibition (Y-27632) modulated the expressions of nuclear factor kappaB (NF-kB) in systemic lupus erythematosus. 20 wild type mice and 20 MRL/lpr mice were applied for the research. The animals were randomly assigned to wild type, wild type + Y-27632 group, MRL/lpr group and MRL/lpr + Y-27632 group. 5 mg/kg Y-27632 was intravenously injected to inhibit the ROCK expressions. Y-27632 significantly decreased the serum levels of interleukin6 (IL-6), IL-1 beta, tumor necrosis factor-alpha (TNF-alpha) and increased IL-10 level in serum of MRL/lpr mice. Flow cytometry (FCM) studies also showed that Y-27632 remarkably increased Regulatory cells(Treg) cell percentage in spleen cells. Western blot analysis demonstrated Y-27632 downregulated the expressions of ROCK1, ROCK2, upregulated the expression of forkhead/winged helix transcription factor(Foxp3), and inhibited the phosphorylations of NF-kBp65 and IkB alpha. The findings showed that the inhibition of ROCK was beneficial for the prevention of systemic lupus erythematosus, which possibly by suppressing NF-kB activation. (C) 2017 Published by Elsevier Masson SAS.