BMP-7 Blocks the Cyclosporine-A-Induced Epithelial-to-Mesenchymal Transition in Renal Tubular Epithelial Cells

Abstract

Aims: The nephrotoxic side effects of cyclosporine A (CsA) are partly due to induction of the epithelial-to-mesenchymal transition (EMT), possibly through upregulation of connective tissue growth factor (CTGF). Bone morphogenetic protein (BMP-7) has been reported to protect against and reverse renal injury via its renotropic and antifibrotic effects. We therefore designed a method to investigate the mechanism by which BMP-7 inhibits CSA-induced EMT in cultured human renal proximal tubular epithelial (HK-2) cells and whether BMP-7 can antagonize CsA-induced profibrogenic effects. Methods: Cultured HK-2 cells were treated with CsA or a combination of CsA and BMP-7 for 72 h. Morphological changes were assessed by phase-contrast microscopy. The expression of α-smooth muscle actin (α-SMA), E-cadherin, collagen type I and CTGF was analyzed by immunofluorescence, RT-PCR, and Western blot. Additionally, the effect of CTGF silencing on CsA-mediated gene expression was assessed. Results: CsA-induced EMT was associated with decreased expression of E-cadherin, increased expression of α-SMA, collagen type I and CTGF, and loss of epithelial morphology. BMP-7 inhibited these effects in a dose-dependent manner. Using siRNA, CTGF knock-down also attenuated EMT-associated phenotypic changes induced by CsA. Conclusion: These data suggest that BMP-7 can block CsA-induced EMT by downregulating the expression of CTGF, a downstream mediator of EMT.

Fasudil Inhibits Epithelial-Myofibroblast Transdifferentiation of Human Renal Tubular Epithelial HK-2 Cells Induced by High Glucose

“…[5][6][7][8] TGF-β 1 is a fibrogenic growth factor contributing to the mechanisms underlying EMT. 12,13) Although TGF-β 1 has been reported to be involved in many cellular signaling pathways, there has been recent interest in the roles of RhoA and ROCK as mediators of some of the actions of TGF-β 1 .…”

“…10,11) Transforming growth factor (TGF)-β 1 is an important fibrogenic growth factor known to play an important role in EMT development. 12,13) Although TGF-β 1 is thought to act via a number of cellular signaling pathways, connective tissue growth factor (CTGF) is a downstream target responsible for many of the pro-fibrotic effects of TGF-β 1 .…”

Identification of novel indicators of cyclosporine A nephrotoxicity in a CD-1 mouse model

“…These included TGF-β1, CTGF and BMP-7 (Zeisberg et al, 2003;Xu et al, 2009). The profibrotic cytokine TGF-β1 is a major contributor to TIF and nephropathy (Ling et al, 2003).…”

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

“…The pathogenesis of DN is complicated; renal fibrosis is the primary pathophysiologic process associated with chronic renal failure caused by DN (5). Epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) accumulation under pathological conditions also occur in mature tubular epithelial cells of the adult kidney, and have been implicated in renal interstitial fibrosis (6,7). It has previously been indicated that a large proportion of interstitial fibrosis cases originate from tubular epithelial cells via EMT in diseased kidneys (8).…”