Induction of epithelial to mesenchymal transition (EMT) and inhibition on adipogenesis: Two different sides of the same coin? Feasible roles and mechanisms of transforming growth factor β1 (TGF-β1) in age-related thymic involution

2016 ◽  
Vol 40 (8) ◽  
pp. 842-846 ◽  
Author(s):  
Jianxin Tan ◽  
Yajun Wang ◽  
Nannan Zhang ◽  
Xike Zhu
2017 ◽  
Vol 313 (4) ◽  
pp. F961-F972 ◽  
Author(s):  
Junpeng Wang ◽  
Yang Chen ◽  
Di Gu ◽  
Guihao Zhang ◽  
Jiawei Chen ◽  
...  

Bladder wall fibrosis is a major complication of ketamine-induced cystitis (KC), but the underlying pathogenesis is poorly understood. The aim of the present study was to elucidate the mechanism of ketamine-induced fibrosis in association with epithelial-to-mesenchymal transition (EMT) mediated by transforming growth factor-β1 (TGF-β1). Sprague-Dawley rats were randomly distributed into four groups, which received saline, ketamine, ketamine combined with a TGF-β receptor inhibitor (SB-505124) for 16 wk, or 12 wk of ketamine and 4 wk of abstinence. In addition, the profibrotic effect of ketamine was confirmed in SV-40 immortalized human uroepithelial (SV-HUC-1) cells. The ketamine-treated rats displayed voiding dysfunction and decreased bladder compliance. Bladder fibrosis was accompanied by the appearance of a certain number of cells expressing both epithelial and mesenchymal markers, indicating that epithelial cells might undergo EMT upon ketamine administration. Meanwhile, the expression level of TGF-β1 was significantly upregulated in the urothelium of bladders in ketamine-treated rats. Treatment of SV-HUC-1 cells with ketamine increased the expression of TGF-β1 and EMT-inducing transcription factors, resulting in the downregulation of E-cadherin and upregulation of fibronectin and α-smooth muscle actin. Administration of SB-505124 inhibited EMT and fibrosis both in vitro and vivo. In addition, withdrawal from ketamine did not lead to recovery of bladder urinary function or decreased fibrosis. Taken together, our study shows for the first time that EMT might contribute to bladder fibrosis in KC. TGF-β1 may have an important role in bladder fibrogenesis via an EMT mechanism.


2018 ◽  
Vol 132 (21) ◽  
pp. 2339-2355 ◽  
Author(s):  
Zhenzhen Li ◽  
Xianghua Liu ◽  
Fengyan Tian ◽  
Ji Li ◽  
Qingwei Wang ◽  
...  

Epithelial-to-mesenchymal transition (EMT) is a phenotypic conversion that plays a crucial role in renal fibrosis leading to chronic renal failure. Mitogen-activated protein kinase phosphatase 2 (MKP2) is a member of the dual-specificity MKPs that regulate the MAP kinase pathway involved in transforming growth factor-β1 (TGF-β1)-induced EMT. However, the function of MKP2 in the regulation of EMT and the underlying mechanisms are still largely unknown. In the present study, we detected the expression of MKP2 in an animal model of renal fibrosis and evaluated the potential role of MKP2 in tubular EMT induced by TGF-β1. We found that the expression of MKP2 was up-regulated in the tubular epithelial of unilateral ureter obstruction rats. Meanwhile, we also demonstrated that TGF-β1 up-regulated MKP2 expression in NRK-52E cells during their EMT phenotype acquisition. Importantly, overexpression of MKP2 inhibited c-Jun amino terminal kinase (JNK) signaling and partially reversed EMT induced by TGF-β1. Moreover, reducing MKP2 expression enhanced JNK phosphorylation, promoted the E-cadherin suppression and induced α-SMA expression and fibronectin secretion in response to TGF-β1, which could be rescued by a JNK inhibitor. These results provide the first evidence that MKP2 is a negative feedback molecule induced by TGF-β1, and MKP2 overexpression inhibits TGF-β1-induced EMT through the JNK signaling pathway. MKP2 could be a promising target to be used in gene therapy for renal fibrosis.


2020 ◽  
Vol 48 (16) ◽  
pp. 8943-8958 ◽  
Author(s):  
Antonio Pezone ◽  
Maria Letizia Taddei ◽  
Alfonso Tramontano ◽  
Jacopo Dolcini ◽  
Francesca Ludovica Boffo ◽  
...  

Abstract The epithelial-to-mesenchymal transition (EMT) is a complex transcriptional program induced by transforming growth factor β1 (TGF-β1). Histone lysine-specific demethylase 1 (LSD1) has been recognized as a key mediator of EMT in cancer cells, but the precise mechanism that underlies the activation and repression of EMT genes still remains elusive. Here, we characterized the early events induced by TGF-β1 during EMT initiation and establishment. TGF-β1 triggered, 30–90 min post-treatment, a nuclear oxidative wave throughout the genome, documented by confocal microscopy and mass spectrometry, mediated by LSD1. LSD1 was recruited with phosphorylated SMAD2/3 to the promoters of prototypic genes activated and repressed by TGF-β1. After 90 min, phospho-SMAD2/3 downregulation reduced the complex and LSD1 was then recruited with the newly synthesized SNAI1 and repressors, NCoR1 and HDAC3, to the promoters of TGF-β1-repressed genes such as the Wnt soluble inhibitor factor 1 gene (WIF1), a change that induced a late oxidative burst. However, TGF-β1 early (90 min) repression of transcription also required synchronous signaling by reactive oxygen species and the stress-activated kinase c-Jun N-terminal kinase. These data elucidate the early events elicited by TGF-β1 and the priming role of DNA oxidation that marks TGF-β1-induced and -repressed genes involved in the EMT.


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