Silencing of the lncRNA TUG1 attenuates the epithelial-mesenchymal transition of renal tubular epithelial cells by sponging miR-141-3p via regulating β-catenin

2020 ◽  
Vol 319 (6) ◽  
pp. F1125-F1134
Author(s):  
Bo Zhang ◽  
Chengguang Zhao ◽  
Ling Hou ◽  
Yubin Wu

Renal interstitial fibrosis (RIF) is characterized by excessive extracellular matrix deposition and involves epithelial-mesenchymal transition (EMT). The lncRNA taurine-upregulated gene 1 ( TUG1) participates in EMT in several cancers; however, the effect and underlying mechanism of TUG1 in RIF-related EMT remain unclear. Here, we explored the mechanisms by which TUG1 modulates RIF. An in vivo model of renal fibrosis was established by unilateral ureteral obstruction in Balb/c mice. Human renal proximal tubular epithelial (HK-2) cells treated with transforming growth factor (TGF)-β1 were used to induce the in vitro model. Morphological changes and TUG1 expression were assessed. HK-2 cells were transfected with siRNA to silence TUG1. Western blot analysis, immunofluorescence staining, cell proliferation, and migration assays were performed to examine TGF-β1-induced changes in EMT markers and EMT-like cell behaviors. TUG1 and β-catenin ( CTNNB1) levels were significantly upregulated, whereas miR-141-3p was significantly downregulated, during EMT in vitro and in vivo. TUG1 knockdown or miR-141-3p overexpression supported the epithelioid morphology of HK-2 cells while enhancing the downregulation of E-cadherin and upregulation of vimentin, α-smooth muscle actin, and β-catenin levels in TGF-β1-treated HK-2 cells. TUG1 knockdown promoted the proliferation and decreased the migration of HK-2 cells and enhanced the downregulation of miR-141-3p levels in TGF-β1-treated HK-2 cells. TUG1 directly targeted miR-141-3p, and miR-141-3p was directly bound to CTNNB1. Downregulation of miR-141-3p inhibited TUG1 silencing-induced suppression of EMT. In conclusion, TUG1 promotes EMT in TGF-β1-induced HK-2 cells via upregulation of β-catenin levels by sponging miR-141-3p, suggesting a novel therapeutic candidate for RIF.

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Weilong Hong ◽  
Ge Zhang ◽  
Hong Lu ◽  
Yangyang Guo ◽  
Shizhang Zheng ◽  
...  

Abstract Background Notch1 signalling is a stem-cell-related pathway that is essential for embryonic development, tissue regeneration and organogenesis. However, the role of Notch1 in the formation of myofibroblasts and fibrosis in kidneys following injury remains unknown. Methods The activity of Notch1 signalling was evaluated in fibrotic kidneys in CKD patients and in ureteral obstructive models in vivo and in cultured fibroblasts and TECs in vitro. In addition, the crosstalk of Notch1 with TGF-β1/Smad2/3 signalling was also investigated. Results Notch1 activity was elevated in fibrotic kidneys of rat models and patients with chronic kidney disease (CKD). Further study revealed that epithelial and interstitial Notch1 activity correlated with an α-SMA-positive myofibroblastic phenotype. In vitro, injury stimulated epithelial Notch1 activation and epithelial-mesenchymal transition (EMT), resulting in matrix deposition in tubular epithelial cells (TECs). Additionally, interstitial Notch1 activation in association with fibroblast-myofibroblast differentiation (FMD) in fibroblasts mediated a myofibroblastic phenotype. These TGF-β1/Smad2/3-dependent phenotypic transitions were abolished by Notch1 knockdown or a specific antagonist, DAPT, and were exacerbated by Notch1 overexpression or an activator Jagged-1-Fc chimaera protein. Interestingly, as a major driving force behind the EMT and FMD, TGF-β1, also induced epithelial and interstitial Notch1 activity, indicating that TGF-β1 may engage in crosstalk with Notch1 signalling to trigger fibrogenesis. Conclusion These findings suggest that epithelial and interstitial Notch1 activation in kidneys following injury contributes to the myofibroblastic phenotype and fibrosis through the EMT in TECs and to the FMD in fibroblasts by targeting downstream TGF-β1/Smad2/3 signalling.


2011 ◽  
Vol 300 (4) ◽  
pp. F1017-F1025 ◽  
Author(s):  
Hongli Lin ◽  
Dapeng Wang ◽  
Taihua Wu ◽  
Cui Dong ◽  
Nan Shen ◽  
...  

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.


Author(s):  
Minmin Song ◽  
Chenrui Cao ◽  
Zhenhua Zhou ◽  
Simin Yao ◽  
Peipei Jiang ◽  
...  

Abstract Intrauterine adhesions (IUAs), the leading cause of uterine infertility, are characterized by endometrial fibrosis. The management of IUA is challenging because the pathogenesis of the disease largely unknown. In this study, we demonstrate that the mRNA and protein levels of high mobility group AT-hook 2 (HMGA2) were increased by nearly 3-fold (P < 0.0001) and 5-fold (P = 0.0095) in the endometrial epithelial cells (EECs) of IUA patients (n = 18) compared to controls. In vivo and in vitro models of endometrial fibrosis also confirmed the overexpression of HMGA2 in EECs. In vitro cell experiments indicated that overexpression of HMGA2 promoted the epithelial–mesenchymal transition (EMT) while knockdown of HMGA2 reversed transforming growth factor-β-induced EMT. A dual luciferase assay confirmed let-7d microRNA downregulated HMGA2 and repressed the pro-EMT effect of HMGA2 in vitro and in vivo. Therefore, our data reveal that HMGA2 promotes IUA formation and suggest that let-7d can depress HMGA2 and may be a clinical targeting strategy in IUA.


2021 ◽  
Author(s):  
Yingjie Zhu ◽  
Dong Sun ◽  
Han Liu ◽  
Linzi Sun ◽  
Jing Jie ◽  
...  

Abstract Background: Accumulating evidence has implicated the potential of natural compounds in treatment of asthma. Bixin is a natural food coloring isolated from the seeds of Bixa Orellana, which possesses anti-tumor, anti-inflammatory and antioxidative properties. Nevertheless, its therapeutic effect in asthma has not been elucidated. Methods: Acute and chronic asthma models of Balb/c mice were established by ovalbumin (OVA) sensitization. For the establishment of a glucocorticoids (GCs) resistant asthma model, Freund’s Adjuvant (CFA) was injected intraperitoneally with OVA. After Bixin treatment, cells in Bronchoalveolar lavage fluid (BALF) were stained with Diff Quick staining and the levels of cytokines were measured by enzyme linked immunosorbent assay (ELISA). The levels of protein in cells and tissues were determined by immunoblotting and/or immunostaining with specific antibodies. The histological changes were determined by Hematoxylin and eosin (H&E), PAS and MASSON staining. Results: Our present study demonstrated that administration of Bixin suppressed allergic airway inflammation and reversed GCs resistance, as well as alleviated airway remodeling and airway hyperresponsiveness (AHR) in asthmatic mice. In vitro studies showed that Bixin treatment could inhibit the development of epithelial-mesenchymal transition (EMT) mediated by transforming growth factor beta (TGF-β) signaling. Importantly, Bixin antagonized activation of phosphatidylinositol 3‑kinase/protein kinase B (PI3K/Akt) pathway both in vitro and in vivo. Conclusions: Above all, our findings reveal that Bixin functions as a potent antagonist of PI3K/Akt signaling to protect against allergic asthma, highlighting a novel strategy for asthma treatment based on natural products.


2010 ◽  
Vol 298 (4) ◽  
pp. F1006-F1017 ◽  
Author(s):  
Li Zhou ◽  
Ping Fu ◽  
Xiao Ru Huang ◽  
Fei Liu ◽  
Arthur C. K. Chung ◽  
...  

Aristolochic acid nephropathy (AAN) has become a worldwide disease and is the most severe complication related to the use of traditional Chinese medicine. However, the pathogenic mechanisms of AAN remain unclear and therapies are limited. The present study tested the hypothesis that transforming growth factor (TGF)-β/Smad3 may be a key pathway leading to chronic AAN. This was examined in vivo in Smad3 wild-type/knockout (WT/KO) mice and in vitro in tubular epithelial cells with knockdown of Smad2 or Smad3. Results revealed that chronic administration of aristolochic acid (AA) resulted in a severe AAN characterized by progressive renal dysfunction and tubulointerstitial fibrosis including epithelial-mesenchymal transition (EMT) in Smad3 WT mice, but not in Smad3 KO mice, suggesting a critical role for Smad3 in the development of AAN. This was further tested in vitro. We found that AA was able to activate Smad signaling to mediate EMT and renal fibrosis via both TGF-β-dependent and JNK/MAP kinase-dependent mechanisms because blockade of JNK and specific knockdown of Smad3, but not Smad2, were able to attenuate AA-stimulated collagen matrix expression and EMT. In conclusion, TGF-β/Smad3 may be an essential mediator for chronic AAN. Results from this study indicate that specific blockade of the TGF-β/Smad3 signaling pathway may have therapeutic potential for chronic AAN.


Author(s):  
Lin Chen ◽  
Azeem Alam ◽  
Aurelie Pac-Soo ◽  
Qian Chen ◽  
You Shang ◽  
...  

AbstractEpithelial–mesenchymal transition (EMT) plays a crucial role in the development of pulmonary fibrosis. This study aims to investigate the effects of valproic acid (VPA) on EMT in vitro and in vivo. In vitro, EMT was induced by the administration of transforming growth factor-β1 (TGF-β1) in a human alveolar epithelial cell line (A549). The dose effects of VPA (0.1–3 mM) on EMT were subsequently evaluated at different timepoints. VPA (1 mM) was applied prior to the administration of TGF-β1 and the expression of E-cadherin, vimentin, p-Smad2/3 and p-Akt was assessed. In addition, the effects of a TGF-β type I receptor inhibitor (A8301) and PI3K-Akt inhibitor (LY294002) on EMT were evaluated. In vivo, the effects of VPA on bleomycin-induced lung fibrosis were evaluated by assessing variables such as survival rate, body weight and histopathological changes, whilst the expression of E-cadherin and vimentin in lung tissue was also evaluated. A8301 and LY294002 were used to ascertain the cellular signaling pathways involved in this model. The administration of VPA prior to TGF-β1 in A549 cells prevented EMT in both a time- and concentration-dependent manner. Pretreatment with VPA downregulated the expression of both p-Smad2/3 and p-Akt. A8301 administration increased the expression of E-cadherin and reduced the expression of vimentin. LY294002 inhibited Akt phosphorylation induced by TGF-β1 but failed to prevent EMT. Pretreatment with VPA both increased the survival rate and prevented the loss of body weight in mice with pulmonary fibrosis. Interestingly, both VPA and A8301 prevented EMT and facilitated an improvement in lung structure. Overall, pretreatment with VPA attenuated the development of pulmonary fibrosis by inhibiting EMT in mice, which was associated with Smad2/3 deactivation but without Akt cellular signal involvement.


2021 ◽  
Vol 135 (1) ◽  
pp. 53-69
Author(s):  
Chuanjian Suo ◽  
Zeping Gui ◽  
Zijie Wang ◽  
Jiajun Zhou ◽  
Ming Zheng ◽  
...  

Abstract Chronic allograft dysfunction is a major cause of late graft failure after kidney transplantation. One of the histological changes is interstitial fibrosis, which is associated with epithelial–mesenchymal transition. Bortezomib has been reported to prevent the progression of fibrosis in organs. We used rat renal transplantation model and human kidney 2 cell line treated with tumor necrosis factor-α (TNF-α) to examine their response to bortezomib. To explore the mechanism behind it, we assessed the previously studied TNF-α/protein kinase B (Akt)/Smad ubiquitin regulatory factor 2 (Smurf2) signaling and performed RNA sequencing. Our results suggested that bortezomib could attenuate the TNF-α-induced epithelial–mesenchymal transition and renal allograft interstitial fibrosis in vitro and in vivo. In addition to blocking Akt/mammalian target of rapamycin (mTOR)/p70S6 kinase/Smurf2 signaling, bortezomib’s effect on the epithelial–mesenchymal transition was associated with inhibition of nuclear factor kappa B (NF-κB) pathway by stabilizing inhibitor of NF-κB. The study highlighted the therapeutic potential of bortezomib on renal allograft interstitial fibrosis. Such an effect may result from inhibition of NF-κB/TNF-α/Akt/mTOR/p70S6 kinase/Smurf2 signaling via stabilizing protein of inhibitor of NF-κB.


2021 ◽  
pp. 096032712110387
Author(s):  
Huali Zhang ◽  
Jiaming Xing ◽  
Lingwei Zhao

Objective TGF-β1-induced excessive deposition of extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT) process of tubular epithelial cells play critical roles in the progression of renal fibrosis. We are aimed to explore the effects of lysine-specific demethylase 1 (LSD1) in TGF-β1-treated HK-2 cells and in rats with unilateral ureteral obstruction (UUO), and to investigate the underlying molecular mechanism. Methods TGF-β1-treated HK-2 cells and UUO-treated rats were used to establish the model of renal fibrosis in vitro and in vivo, respectively. Protein expression of LSD1, E-cadherin, a-smooth muscle actin (a-SMA), Vimentin, Jagged-1, Notch-1 and Notch-2 were detected by Western blot. The concentrations of type I collagen (Col-I) and Fibronectin (FN) were measured by ELISA. Transwell assay were used to assess cell invasion. Results LSD1 was dramatically increased in TGF-β1-stimulated HK-2 cells. Knockdown of LSD1 decreased the TGF-β1-induced secretion of Col-I and FN, and suppressed TGF-β1-induced expression of E-cadherin,α-SMA and Vimentin, while suppressed cell invasion. Consistent with the in vitro data, the severe histopathological damage, collagen deposition and reduced E-cadherin, increased α-SMA induced by UUO was abated by the knockdown of LSD1 in vivo. Moreover, knockdown of LSD1 suppressed TGF-β1-induced expression of Jagged-1, Notch-1 and Notch-2. Furthermore, we found that inhibition of Notch signaling by a γ-secretase inhibitor RO4929097 almost recapitulated the effects of LSD1 knockdown in TGF-β1-induced HK-2 cells, and at least in part reversed the effects of LSD1 overexpression on EMT and ECM deposition in HK-2 cells. Conclusions Taken together, LSD1 significantly impact on the progression of TGF-β1-mediated EMT and ECM deposition in HK-2 cells, and it may represent novel target for the prevention strategies of renal fibrosis.


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