Abstract 132: Hypoxia-inducible Factor Prolyl-hydroxylase-2 Mediates Transforming Growth Factor Beta 1-induced Epithelial-mesenchymal Transition In Renal Tubular Cells

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Weiqing Han ◽  
Jun-Pin Hu ◽  
Pin-Lan Li ◽  
Ningjun Li
Keyword(s):  
Signaling Pathway ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Kidney Diseases ◽  
Hypoxia Inducible Factor ◽  
Mesenchymal Transition ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Renal Tubular

Transforming growth factor beta 1 (TGFβ1)-induced epithelial-mesenchymal transition (EMT) in kidney epithelial cells plays a key role in renal tubulointerstitial fibrosis in chronic kidney diseases. As hypoxia-inducible factor (HIF)-1α is found to mediate TGFβ1 signaling pathway, we tested the hypothesis that HIF-1α and its upstream regulator prolyl hydroxylase domain-containing proteins (PHDs) are involved in TGFβ1-induced EMT in renal tubular cells. Our results showed that TGFβ1 treatment for 48 h stimulated EMT in cultured renal tubular cells as indicated by the decrease in epithelial marker P-cadherin from 1.0 ± 0.02 to 0.40 ± 0.05 ( P < 0.05), and the increase in mesenchymal markers α-smooth muscle actin (2.14 ± 0.32 fold, P < 0.05) and fibroblast-specific protein (2.0 ± 0.17 fold, P < 0.05) as shown in Western blot assay. Meanwhile, TGFβ1 time-dependently increased HIF-1α, which reached its maximum value (2.36 ± 0.2 fold, P < 0.05) at 24 h, and that HIF-1α siRNA significantly inhibited TGFβ1-induced EMT, suggesting that HIF-1α mediated TGFβ1 induced-EMT. Real-time PCR showed that PHD1 and PHD2, rather than PHD3, could be detected, with PHD2 as the predominant form of PHDs (PHD1 : PHD2 = 0.21:1.0). Importantly, TGFβ1 time-dependently decreased PHD2 mRNA and protein level, which reached their maximum value from 1.0 ± 0.15 to 0.45 ± 0.08 ( P < 0.05) for mRNA at 16 h and from 1.0 ± 0.08 to 0.26 ± 0.08 ( P < 0.05) for protein at 24 h, respectively. In contrast, TGFβ1 had no effect on PHD1 mRNA and protein levels. Furthermore, over-expression of PHD2 transgene almost fully prevented TGFβ1-induced HIF-1α accumulation and EMT marker changes, indicating that PHD2 is involved in TGFβ1-induced EMT. Finally, Smad2 inhibitor SB431542 prevented TGFβ1-induced PHD2 decrease, suggesting that Smad2 may mediate TGFβ1-induced EMT through PHD2/HIF-1α. It is concluded that TGFβ1 decreased PHD2 expression via a Smad2-dependent signaling pathway, thereby leading to HIF-1α accumulation and EMT in renal tubular cells. The present study suggests that PHD2/HIF-1α is a novel signaling pathway mediating the fibrogenic effect of TGFβ1 and that manipulating PHD2/HIF-1α pathway may be used as a therapeutic strategy in chronic kidney diseases. (support: NIH grant HL89563 and HL106042)

The Effects of Cyclosporine on Protein Expression of P53 and Transforming Growth Factor-Beta in Human Renal Tubular Cells

2000 ◽  
Vol 6 (S2) ◽  
pp. 604-605
Author(s):  
H. Song ◽  
C. Wei
Keyword(s):  
Growth Factor ◽  
Cyclosporine A ◽  
Transforming Growth Factor Beta ◽  
Renal Cell ◽  
Transforming Growth Factor ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Cellular Apoptosis ◽  
Growth Factor Beta ◽  
Renal Tubular

Cyclosporine-A (CsA) is the widely used immunosuppressant drug in renal transplantation. However, the effects of cyclosporine-A are limited by a significant nephrotoxicity. The mechanisms of CsA-induced allograft nephropathy are remaining controversial. Recent study indicated that cellular apoptosis may contribute to the cyclosporine A-mediated cytotoxic action. To date, regarding the effects of cyclosporine A on renal cell apoptosis-related gene expression remain poorly defined. p53 is an important gene in control of renal cell growth and death. Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine that has anti-proliferative as well as fibrogenic properties.We hypothesized that cyclosporine-A may increase p53 and TGF-β expression in renal tubular cells. These actions of cyclosporine-A may contribute to the cellular apoptosis, fibrosis and CsA-induced nephrotoxicity. Therefore, current study was designed to determine the effects of cyclosporine-A on the p53 and TGF-βl protein expression by immunohistochemical staining (IHCS) in cultured human tubular cells.

Blocking core fucosylation of TGF-β1 receptors downregulates their functions and attenuates the epithelial-mesenchymal transition of renal tubular cells

2011 ◽  
Vol 300 (4) ◽  
pp. F1017-F1025 ◽  
Author(s):  
Hongli Lin ◽  
Dapeng Wang ◽  
Taihua Wu ◽  
Cui Dong ◽  
Nan Shen ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Interstitial Fibrosis ◽  
Cell Model ◽  
Mesenchymal Transition ◽  
Renal Tubular Cells ◽  
Renal Tubular ◽  
Core Fucosylation ◽  
Tgf Β1

Posttranslational modification of proteins could regulate their multiple biological functions. Transforming growth factor-β receptor I and II (ALK5 and TGF-βRII), which are glycoproteins, play important roles in the renal tubular epithelial-mesenchymal transition (EMT). In the present study, we examined the role of core fucosylation of TGF-βRII and ALK5, which is regulated by α-1,6 fucosyltransferase (Fut8), in the process of EMT of cultured human renal proximal tubular epithelial (HK-2) cells. The typical cell model of EMT induced by TGF-β1 was constructed to address the role of core fucosylation in EMT. Core fucosylation was found to be essential for both TGF-βRII and ALK5 to fulfill their functions, and blocking it with Fut8 small interfering RNA greatly reduced the phosphorylation of Smad2/3 protein, caused the inactivation of TGF-β/Smad2/3 signaling, and resulted in remission of EMT. More importantly, even with high levels of expressions of TGF-β1, TGF-βRII, and ALK5, blocking core fucosylation also could attenuate the EMT of HK-2 cells. Thus blocking core fucosylation of TGF-βRII and ALK5 may attenuate EMT independently of the expression of these proteins. This study may provide new insight into the role of glycosylation in renal interstitial fibrosis. Furthermore, core fucosylation may be a novel potential therapeutic target for treatment of renal tubular EMT.

High Uric Acid-Induced Epithelial-Mesenchymal Transition of Renal Tubular Epithelial Cells via the TLR4/NF-kB Signaling Pathway

2017 ◽  
Vol 46 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Huifang Liu ◽  
Jiachuan Xiong ◽  
Ting He ◽  
Tangli Xiao ◽  
Yan Li ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Signaling Pathway ◽  
Epithelial Mesenchymal Transition ◽  
Interstitial Fibrosis ◽  
Morphological Changes ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Mesenchymal Transition ◽  
Renal Tubular Cells ◽  
Renal Tubular

Background: Hyperuricemia is an independent risk factor for causing chronic kidney disease and contributes to kidney fibrosis. After urate crystals get deposited in the kidney, they can cause hyperuricemia nephropathy, leading to glomerular hypertrophy and renal tubular interstitial fibrosis. Recent data showed that uric acid (UA) could induce epithelial mesenchymal transition (EMT) of renal tubular cells, in which NRLP3 inflammatory pathway was involved. However, whether TLR4/NF-κB signaling pathway is also involved in EMT of renal tubular cells induced by UA is not clear. Methods: Human renal tubular epithelial cells (HK-2) were directly treated with UA and the phenotypic transition was detected by morphological changes and the molecular markers of EMT. The activation of the TLR4/NF-κB signaling pathway induced by UA was measured by Western blot and its involvement was further confirmed by the inhibition of NF-κB activation or knockdown of toll like receptor 4 (TLR4) expression. Results: UA induced obvious morphological changes of HK-2 cell, accompanied with altered molecular markers of EMT including fibronectin, α-SMA and E-cadherin. In addition, UA significantly upregulated the gene expression of interleukin-1β and tumor necrosis factor-α in a time- and dose-dependent manner. Furthermore, UA significantly activated the TLR4/NF-κB signaling pathway in HK-2 cells, while the inhibition of the TLR4 expression by siRNA and NF-κB activation by PDTC significantly attenuated EMT induced by UA in HK-2 cells. Conclusions: UA can induce EMT in renal tubular epithelial cells by the activation of the TLR4/NF-κB signaling pathway, and the targeted intervention of the TLR4/NF-κB signaling pathway might effectively inhibit UA-induced renal interstitial fibrosis mediated by EMT.

Abstract 210: Stem Cell Conditioned Culture Media Attenuated Albumin-induced Epithelial-mesenchymal Transition in Renal Tubular Cells

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Junping Hu ◽  
Weiqing Han ◽  
Qing Zhu ◽  
Pin-Lan Li ◽  
Ningjun Li
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Culture Media ◽  
Mesenchymal Transition ◽  
Tubular Cells ◽  
Protein Levels ◽  
Renal Tubular Cells ◽  
Proximal Tubular ◽  
Renal Proximal Tubular Cells ◽  
Renal Proximal Tubular ◽  
Renal Tubular

Mesenchymal stem cells (MSCs) have been shown to be a promising therapy for many different diseases. Stem cell conditioned culture media (SCM) exhibit similar beneficial effects as MSCs. Albuminuria-induced epithelial-mesenchymal transition (EMT) plays an important role in progressive renal tubulointerstitial fibrosis in chronic renal disease. The present study tested the hypothesis that SCM inhibit albumin-induced EMT in cultured renal tubular cells. SCM were obtained by culturing rat adult MSCs for 3 days. Cultured renal proximal tubular cells were incubated with rat albumin (20μg/ml) and treated with SCM or control culture media. Our results showed that 48 h albumin incubation stimulated EMT in renal proximal tubular cells as shown by significant decrease in the protein levels of epithelial marker E-cadherin from 2.30 ± 0.27 to 0.87 ± 0.11 ( P < 0.05) and increase in the protein levels of mesenchymal marker fibroblast-specific protein 1 (FSP-1) (2.18±0.33 folds, P < 0.05). SCM treatment significantly inhibited these albumin-induced changes in E-cadherin and FSP-1 by 2.33±0.17 and 1.95±0.23 folds ( P < 0.05), respectively. Meanwhile, albumin increased the mRNA levels of pro-inflammatory factor monocyte chemoattractant protein-1 (MCP)-1 by nearly 30 folds compared with control. SCM almost abolished the increase of MCP-1 induced by albumin. Furthermore, Western blot results displayed that albumin rapidly decreased the cytosolic levels and increased the nuclear levels of NF-κB, indicating a translocation of NF-κB; immunofluorescence microscopy also demonstrated that albumin induced NF-κB translocation from the cytosol into nucleus. SCM blocked the translocation of NF-κB into nucleus. These results suggest that SCM attenuated albumin-induced EMT in renal tubular cells via inhibiting NF-κB activation and inflammation, which may serve as a new therapeutic approach for chronic kidney diseases. (Supported by NIH grant HL89563 and HL106042)

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