scholarly journals Nrf2-Heme Oxygenase-1 Attenuates High-Glucose-Induced Epithelial-to-Mesenchymal Transition of Renal Tubule Cells by Inhibiting ROS-Mediated PI3K/Akt/GSK-3β Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jong Ho Shin ◽  
Kyeong Min Kim ◽  
Jin Uk Jeong ◽  
Jae Min Shin ◽  
Ju Hyung Kang ◽  
...  

Background. Epithelial-to-mesenchymal transition (EMT) is thought to play a significant role in the advancement to chronic kidney disease and contributes to the deposition of extracellular matrix proteins and renal fibrosis relating to diabetic nephropathy. Method. We studied the effect of Nrf2-HO-1 signaling on high-glucose- (HG-) induced EMT in normal human tubular epithelial cells, that is, HK2 cells. In short, we treated HK2 cells with HG and sulforaphane (SFN) as an Nrf2 activator. EMT was evaluated by the expression activity of the epithelial marker E-cadherin and mesenchymal markers such as vimentin and fibronectin. Results. Exposure of HK2 cells to HG (60 mM) activated the expression of vimentin and fibronectin but decreased E-cadherin. Treatment of HK2 cells with SFN caused HG-induced attenuation in EMT markers with activated Nrf2-HO-1. We found that SFN decreased HG-induced production of reactive oxygen species (ROS), phosphorylation of PI3K/Akt at serine 473, and inhibitory phosphorylation of serine/threonine kinase glycogen synthase kinase-3β (GSK-3β) at serine 9. Subsequently, these signaling led to the downregulation of the Snail-1 transcriptional factor and the recovery of E-cadherin. Conclusion. The present study suggests that Nrf2-HO-1 signaling has an inhibitory role in the regulation of EMT through the modulation of ROS-mediated PI3K/Akt/GSK-3β activity, highlighting Nrf2-HO-1 and GSK-3β as potential therapeutic targets in diabetic nephropathy.

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Shoujun Bai ◽  
Xiaoyan Xiong ◽  
Bo Tang ◽  
Tingting Ji ◽  
Xiaoying Li ◽  
...  

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. The association between epithelial-mesenchymal transition (EMT) and fibrosis is quite ascertained, but its link to eventual tubule dysfunction is missing. Here, we show that human microRNA- (hsa-miR-) 199b-3p protects renal tubules from diabetic-induced injury by repressing KDM6A, a histone lysine demethylase regulating E-cadherin expression. Lower E-cadherin expression is related to a higher level of KDM6A, while E-cadherin is promoted upon treatment with the KDM6A inhibitor GSK-J4 in both high glucose- (HG-) induced HK2 cells and the kidneys from streptozotocin- (STZ-) induced type 1 diabetic mice. However, overexpression or RNA silencing of E-cadherin fails to alter KDM6A expression. We also show that the upregulation of KDM6A is associated with the increased methylation level of the E-cadherin promoter. Then, the target prediction results and a dual-luciferase assay show that hsa-miR-199b-3p is a new miRNA that targets KDM6A. Overexpression of hsa-miR-199b-3p increases E-cadherin expression and prevents EMT through repressing KDM6A expression in HG-induced HK2 cells. In contrast, inhibitor-induced hsa-miR-199b-3p knockdown has opposite effects, as it decreases E-cadherin level and worsens EMT, accompanied by increased levels of KDM6A. Besides, Mir199b-knockout mice without mmu-miR-119b-3p expression exhibit more renal tubule dysfunction and more serious kidney tissue damage upon treatment with STZ. These results demonstrate that hsa-miR-199b-3p improves E-cadherin expression and prevents the progression of DN through targeting KDM6A. miR-199b-3p could be a future biomarker or target for the diagnosis or treatment of DN.


2010 ◽  
Vol 298 (5) ◽  
pp. F1263-F1275 ◽  
Author(s):  
Yu Jin Lee ◽  
Ho Jae Han

Peroxisome proliferator-activated receptor-γ (PPARγ) agonists ameliorate renal fibrotic lesions in diabetic nephropathy. However, the effects of the agonists on the epithelial-mesenchymal transition (EMT) linked to membrane transport dysfunction are unknown. The present study aimed to verify the effects of the PPARγ agonist troglitazone on high glucose (HG)-induced EMT in primary cultured renal proximal tubular epithelial cells (PTCs). HG (25 mM) as well as hydrogen peroxide (H2O2) and transforming growth factor-β1 (TGF-β1) decreased expression of epithelial cell marker E-cadherin and increased the expression of the mesenchymal markers vimentin and α-smooth muscle actin (α-SMA). HG, H2O2, and TGF-β1 decreased Na+/H+ exchangers (NHEs) or Na+-glucose cotransporters (SGLTs) and glucose uptake, showing membrane transport dysfunction. HG stimulated the production of cellular reactive oxygen species (ROS), and antioxidants blocked the HG-induced increase in phosphatidylinositol 3-kinase (PI3K)/Akt activation. Antioxidants and inhibitors of PI3K/Akt reversed HG-induced EMT protein expression. Inhibition of PI3K/Akt also blocked HG-induced glycogen synthase kinase-3β (GSK-3β) phosphorylation. HG and lithium chloride (GSK-3β inhibitor) blocked Snail1 and β-catenin activation. Moreover, transfection with Snail1 or β-catenin small interfering RNA (siRNA) reversed HG-induced EMT protein expression. Importantly, HG decreased PPARγ activation and troglitazone reversed HG-induced expression of PI3K/Akt, GSK-3β, Snail1, and β-catenin as well as EMT proteins. Finally, inhibitors of PI3K/Akt, Snail1/β-catenin siRNA, and troglitazone blocking the HG-induced EMT restored glucose uptake in PTCs. In conclusion, HG induces EMT through ROS, PI3K/Akt, GSK-3β, Snail, and β-catenin. Subsequently, HG-induced EMT may result in SGLT dysfunction that is restored by the PPARγ agonist troglitazone in primary cultured PTCs.


2018 ◽  
Vol 51 (6) ◽  
pp. 2794-2813 ◽  
Author(s):  
Manshu Yu ◽  
Jun Shi ◽  
Meixiao Sheng ◽  
Kun Gao ◽  
Lu Zhang ◽  
...  

Background/Aims: The epithelial-to-mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) is a crucial event in the induction of peritoneal fibrosis (PF), in which canonical Wnt/β-catenin signaling participates. Smads signaling is reported to interact with β-catenin and synergistically regulates EMT. This study was aimed to reveal the effect of Astragalus on β-catenin in EMT of PMCs. Methods: To obtain the role of β-catenin in EMT, gene transfer into HMrSV5 cell line and rats has been achieved. After Astragalus treatment, EMT markers and signaling pathway-related indicators were detected by western blotting, immunofluorescence, immunohistochemistry, immunoprecipitation and real time-PCR. Results: β-catenin knockdown suppressed EMT of HMrSV5 cells. Astragalus alleviated EMT of PMCs characterized by increased E-cadherin and decreased α-SMA and Vimentin. In rat model of peritoneal dialysis (PD), Astragalus attenuated peritoneal thickening and fibrosis. Astragalus down-regulated β-catenin by stabilizing the Glycogen synthase kinase-3β (GSK-3β)/β-catenin complex and further inhibited the nuclear translocation of β-catenin. Meanwhile, Astragalus down-regulated β-catenin by enhancing Smad7 expression. Silencing Smad7 antagonized the EMT-inhibitory effect of Astragalus. Conclusion: Astragalus inhibits EMT of PMCs by down-regulating β-catenin. The modulation of β-catenin in peritoneum can be a novel tool to prevent PF.


2021 ◽  
Author(s):  
Zhao Chen ◽  
Lifang Tian ◽  
Li Wang ◽  
Xiaotao Ma ◽  
Fuqian Lei ◽  
...  

Abstract Hyperglycemia-induced oxidative stress of podocytes exerts a major role in the pathological process of diabetic nephropathy. Tripartite motif-containing protein 32 (TRIM32) has been reported as a key protein in the modulation of cellular apoptosis and oxidative stress under various pathological processes. However, whether TRIM32 participates in the regulation of high glucose (HG)-induced injury in podocytes has not been investigated. The aims of this work were to assess the possible role of TRIM32 in mediating HG-induced apoptosis, oxidative stress and inflammatory response in podocytes in vitro. Herein, our results showed a marked increase in TRIM32 expression in HG-exposed podocytes. Loss-of-function experiments showed that the knockdown of TRIM32 improved the viability of HG-stimulated podocytes, and suppressed HG-induced apoptosis, oxidative stress and inflammatory response in podocytes. Further investigation revealed that the inhibition of TRIM32 enhanced the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling associated with modulation of the Akt/glycogen synthase kinase-3β (GSK-3β) axis in podocytes following HG exposure. However, the suppression of Akt abrogated the TRIM32-knockdown-mediated activation of Nrf2 in HG-exposed podocytes. In addition, the knockdown of Nrf2 markedly abolished the TRIM32-inhibition-induced protective effects in HG-exposed podocytes. In summary, the results of this work show that the inhibition of TRIM32 protects podocytes from HG-induced injury by potentiating Nrf2 signaling via the modulation of Akt/GSK-3β signaling. This study indicates a potential role of TRIM32 in mediating podocyte injury during the progression of diabetic nephropathy.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Lihong Lu ◽  
Ziwen Zhong ◽  
Jiahui Gu ◽  
Ke Nan ◽  
Minmin Zhu ◽  
...  

Abstract Background Diabetic nephropathy (DN) is currently the leading cause of end-stage renal disease globally. The endothelial-to-mesenchymal transition (EndMT) of glomerular endothelial cells has been reported to play a crucial role in DN. As a specific form of epithelial-to-mesenchymal transition, EndMT and epithelial-to-mesenchymal transition may exhibit mutual modulators. Profilin 2 (PFN2) has been reported to participate in epithelial-to-mesenchymal transition. Moreover, ETS proto-oncogene 1 (ets1) and lysine methyltransferase 5A (KMT5A) have been reported to contribute to high glucose-mediated endothelial injury and epithelial-to-mesenchymal transition. In this study, we hypothesize ets1 associates with KMT5A to modulate PFN2 transcription, thus participating in high glucose-mediated EndMT in glomerular endothelial cells. Methods Immunohistochemistry (IHC) was performed to detect protein levels in the kidney tissues and/or aorta tissues of human subjects and rats. Western blot, qPCR and immunofluorescence were performed using human umbilical vein endothelial cells (HUVECs). Chromatin immunoprecipitation (ChIP) assays and dual luciferase assays were performed to assess transcriptional activity. The difference between the groups was compared by two-tailed unpaired t-tests or one-way ANOVAs. Results Our data indicated that vimentin, αSMA, S100A4 and PFN2 levels were increased, and CD31 levels were reduced in glomerular endothelial cells of DN patients and rats. Our cell experiments showed that high glucose induced EndMT by augmenting PFN2 expression in HUVECs. Moreover, high glucose increased ets1 expression. si-ets1 suppressed high glucose-induced PFN2 levels and EndMT. ets1 overexpression-mediated EndMT was reversed by si-PFN2. Furthermore, ets1 was determined to associate with KMT5A. High glucose attenuated KMT5A levels and histone H4 lysine 20 methylation (H4K20me1), one of the downstream targets of KMT5A. KMT5A upregulation suppressed high glucose-induced PFN2 levels and EndMT. sh-KMT5A-mediated EndMT was counteracted by si-PFN2. Furthermore, H4K20me1 and ets1 occupied the PFN2 promoter region. sh-KMT5A cooperated with ets1 overexpression to activate PFN2 promoter activity. Our in vivo study demonstrated that KMT5A was reduced, while ets1 was augmented, in glomerular endothelial cells of DN patients and rats. Conclusions The present study indicated that ets1 cooperated with KMT5A to transcribe PFN2, thus contributing to hyperglycemia-induced EndMT in the glomerular endothelial cells of DN patients and rats. Trial registration ChiCTR, ChiCTR2000029425. 2020/1/31, http://www.chictr.org.cn/showproj.aspx?proj=48548


2020 ◽  
Vol 19 (4) ◽  
pp. 739-744
Author(s):  
Xi Zhao ◽  
Yao-Guang Wang ◽  
Xi-kai Yang ◽  
Man Li ◽  
Shi-Jie Liu ◽  
...  

Purpose: To investigate the anti-fibrotic effects of tanshinone IIA (TS) on renal tubular epithelial cells (HK-2 cells) under high glucose conditions and their related molecular mechanism(s) of action.Methods: After treatment with TS (6 μg/mL) for 24 h, the morphology of HK-2 cells stimulated by high glucose was observed under the microscope. Additionally, potential mechanisms related to the antifibrosis effects of TS were evaluated using western blotting assay and quantitative real time PCR (qRTPCR), including transforming growth factor (TGF) β1, α-smooth muscle actin (α-SMA), heme oxygenase 1 (HO-1), laminin (LN), fibronectin (FN), and E-cadherin (E-cad).Results: A high-glucose culture environment induced fibrosis of HK-2 cells, as indicated by changes in cell morphology. The anti-fibrotic effects of TS were mainly associated with a decrease in the expression levels of TGF-β1, α-SMA and LN, while the expression of E-cad increased. These resultsalso revealed that TS increased the expressions of HO-1.Conclusion: The findings suggest that TS suppresses fibrosis caused by high glucose in HK-2 cells by inhibiting extracellular matrix deposition and epithelial-mesenchymal transition and by reducing oxidative stress. Further investigations are needed to evaluate the clinical application of this compound in diabetic nephropathy. Keywords: Tanshinone IIA, Diabetic nephropathy, HK-2 cells, Fibrosis


2019 ◽  
Vol 23 (8) ◽  
pp. 1050-1057
Author(s):  
Nada M. Qamar El-Dawla ◽  
Al-Aliaa M. Sallam ◽  
Mohamed H. El-Hefnawy ◽  
Hala O. El-Mesallamy

2014 ◽  
Vol 306 (5) ◽  
pp. F486-F495 ◽  
Author(s):  
Jin-yang Wang ◽  
Yan-bin Gao ◽  
Na Zhang ◽  
Da-wei Zou ◽  
Li-ping Xu ◽  
...  

Diabetic nephropathy (DN) is one of the most important diabetic microangiopathies. The epithelial-to-mesenchymal transition (EMT) plays an important role in DN. The physiological role of microRNA-21 (miR-21) was closely linked to EMT. However, it remained elusive whether tongxinluo (TXL) ameliorated renal structure and function by regulating miR-21-induced EMT in DN. This study aimed to determine the effect of TXL on miR-21-induced renal tubular EMT and to explore the relationship between miR-21 and TGF-β1/smads signals. Real-time RT-PCR, cell transfection, in situ hybridization (ISH), and laser confocal microscopy were used, respectively. Here, we revealed that TXL dose dependently lowered miR-21 expression in tissue, serum, and cells. Overexpression of miR-21 can enhance α-smooth muscle actin (SMA) expression and decrease E-cadherin expression by upregulating smad3/p-smad3 expression and downregulating smad7 expression. Interestingly, TXL also increased E-cadherin expression and decreased α-SMA expression by regulating miR-21 expression. More importantly, TXL decreased collagen IV, fibronectin, glomerular basement membrane, glomerular area, and the albumin/creatinine ratio, whereas it increased the creatinine clearance ratio. The results demonstrated that TXL ameliorated renal structure and function by regulating miR-21-induced EMT, which was one of the mechanisms to protect against DN, and that miR-21 may be one of the therapeutic targets for TXL in DN.


2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Pengpeng Yan ◽  
Huanna Tang ◽  
Xiaoying Chen ◽  
Shuiyu Ji ◽  
Wei Jin ◽  
...  

Peritoneal fibrosis is a severe complication arising from long-term peritoneal dialysis (PD). Tamoxifen (Tamo) has been clinically proven effective in a series of fibrotic diseases, such as PD-associated encapsulating peritoneal sclerosis (EPS), but the mechanisms underlying Tamoxifen’s protective effects are yet to be defined. In the present study, C57BL/6 mice received intraperitoneal injections of either saline, 4.25% high glucose (HG) PD fluid (PDF) or PDF plus Tamoxifen each day for 30 days. Tamoxifen attenuated thickening of the peritoneum, and reversed PDF-induced peritoneal expression of E-cadherin, Vimentin, matrix metalloproteinase 9 (MMP9), Snail, and β-catenin. Mouse peritoneal mesothelial cells (mPMCs) were cultured in 4.25% glucose or 4.25% glucose plus Tamoxifen for 48 h. Tamoxifen inhibited epithelial-to-mesenchymal transition (EMT) as well as phosphorylation of glycogen synthase kinase-3β (GSK-3β), nuclear β-catenin, and Snail induced by exposure to HG. TWS119 reversed the effects of Tamoxifen on β-catenin and Snail expression. In conclusion, Tamoxifen significantly attenuated EMT during peritoneal epithelial fibrosis, in part by inhibiting GSK-3β/β-catenin activation.


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