SO013CRUCIAL ROLE OF SERUM RESPONSE FACTOR IN EPITHELIAL-MESENCHYMAL TRANSITION OF RENAL TUBULAR EPITHELIAL CELLS IN HYPERUREICEMIC NEPHROPATHY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Long Zhao ◽  
Yan Xu

Abstract Background and Aims To investigate the role of serum response factor (SRF) in epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) in hyperuricemic nephropathy (HN). Method The expression of SRF, epithelial markers (E-cadherin and ZO-1) and mesenchymal markers (fibronectin, α-SMA, FSP-1) was examined in rat renal tubular epithelial cells (NRK-52E cells) or renal medulla tissues following uric acid (UA). SRF was upregulated by SRF plasmids and downregulated by CCG-1423(a small molecule inhibitor of SRF) to investigate how SRF influenced EMT in TECs of HN. Oxonic acid (OA) was used to generate HN in rats. Results Conclusion Together, increased SRF activity promotes EMT and dysfunction of TECs in HN. Targeting SRF by small molecule inhibitor may be an attractive therapeutic strategy for HN.

2016 ◽  
Vol 48 (8) ◽  
pp. 580-588 ◽  
Author(s):  
Long Zhao ◽  
Lingzhen Chi ◽  
Jun Zhao ◽  
Xueling Wang ◽  
Zhixin Chen ◽  
...  

We investigated the role of serum response factor (SRF) in epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) in diabetic nephropathy (DN). The expression of SRF, epithelial markers (E-cadherin and ZO-1), and mesenchymal markers (fibronectin, collagen-1, α-SMA, FSP-1) was examined in human proximal renal tubular epithelial cells (HK-2 cells) or renal medulla tissues following high glucose. SRF was upregulated by SRF plasmids and downregulated by CCG-1423 (a small molecule inhibitor of SRF) to investigate how SRF influenced EMT in TECs of DN. Streptozotocin was used to generate DM in rats. In HK-2 cells after high-glucose treatment and renal medulla tissues of diabetic rats, SRF, fibronectin, collagen-1, α-SMA, and FSP-1 increased, while E-cadherin and ZO-1 declined. SRF overexpression in HK-2 cells induced expression of Snail, an important transcription factor mediating EMT. Blockade of SRF by CCG-1423 reduced Snail induction and protected TECs from EMT both in vitro and in vivo. Together, increased SRF activity promotes EMT in TECs and dysfunction in DN. Targeting SRF by small molecule inhibitor may be an attractive therapeutic strategy for DN.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinyun Pu ◽  
Yu Zhang ◽  
Jianhua Zhou

Epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells is a vital mechanism of renal fibrosis. Mounting evidence suggests that miR-200a expression decreases in tubular epithelial cells in unilateral ureteral obstruction (UUO) rats. Moreover, it has been demonstrated that Huai Qi Huang (HQH) can ameliorate tubulointerstitial damage in adriamycin nephrosis and delay kidney dysfunction in primary glomerular disease. However, the effect of HQH on EMT of tubular epithelial cells in UUO rats and its molecular mechanism is unclear. In order to explore the effect of HQH on EMT and its molecular mechanism in renal fibrosis,in vitroandin vivoexperiments were performed in our study. Our results showed that HQH increased miR-200a expression in UUO rats and in TGF-β1 stimulated NRK-52E cells. Meanwhile, HQH decreased ZEB1 and ZEB2 (the transcriptional repressors of E-cadherin),α-SMA expression in renal tubular epithelial cellsin vitroandin vivo. Furthermore, we found that HQH protected kidney from fibrosis in UUO rats. The results demonstrated that HQH regulated miR-200a/ZEBs pathway and inhibited EMT process, which may be a mechanism of protecting effect on tubular cells in renal fibrosis.


2017 ◽  
Vol 46 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Huifang Liu ◽  
Jiachuan Xiong ◽  
Ting He ◽  
Tangli Xiao ◽  
Yan Li ◽  
...  

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Li-Cai Zhang ◽  
Zong-Bin Wei ◽  
Shui-Fu Tang

Renal fibrosis, the leading cause of end-stage renal disease and in which epithelial-mesenchymal transition (EMT) plays a central role, has a complex pathogenesis that is not fully understood. Therefore, we investigated the role of the long noncoding RNA LUCAT1 in the EMT of renal tubular epithelial cells under high-glucose (HG) conditions and the underlying mechanism involved. In this study, we established HG and normal glucose groups of HK-2 cells by treating HK-2 cells 30.0 or 5.5 mmol/L glucose, respectively. To investigate the roles of LUCAT1 and miR-199a-5p in HG-induced EMT, we transfected the HG group with negative control small interfering RNA (siRNA), siRNA targeting LUCAT1, negative control microRNA, or an miR-199a-5p mimic. The results of the quantitative reverse transcription PCR indicated that the LUCAT1 level in the HG group was increased, whereas the miR-199a-5p level was decreased. The EMT in the cells was induced by treatment with HG but was weakened by LUCAT1 knockdown or miR-199a-5p overexpression, which both also inhibited the HG-induced phosphorylation of SMAD3. Moreover, LUCAT1 and ZEB1 mRNA comprised the same microRNA response elements of miR-199a-5p. LUCAT1 knockdown had no effect on the miR-199a-5p level but decreased the HG-induced upregulation of ZEB1. In conclusion, HG conditions induced the upregulation of LUCAT1, and LUCAT1 knockdown inhibited the EMT in HG-treated HK-2 cells. LUCAT1 likely promotes HG-induced EMT through ZEB1 by sponging miR-199a-5p.


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