TGF-β participates in epithelial-mesenchymal transition in pleural fibrosis via targeting S100A4

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase [NOX] enzymes serve several hemostatic and host defense functions in various lung diseases, but the role of NOX4 signaling in tuberculous pleurisy is not well understood. The role of NOX4 signaling in tuberculous pleural fibrosis was studied using invitro pleural mesothelial cell (PMC) experiments and a murine model of Mycobacterium bovis bacillus Calmette–Guérin (BCG) pleural infection. The production of NOX4 reactive oxygen species (NOX4–ROS) and the epithelial mesenchymal transition (EMT) in PMCs were both induced by heat-killed mycobacterium tuberculosis (HKMT). In cultured PMCs, HKMT-induced collagen-1 synthesis and EMT were blocked by pretreatment with small interfering RNA (siRNA) NOX4. Moreover, NOX4–ROS production and subsequent fibrosis were reduced by treatment with losartan and the toll-like receptor 4 (TLR4) inhibitor TAK-242. The HKMT-induced EMT and intracellular ROS production were mediated by NOX4 via the activation of extracellular signal-regulated kinase (ERK) signaling. Finally, in a BCG-induced pleurisy model, recruitment of inflammatory pleural cells, release of inflammatory cytokines, and thickened mesothelial fibrosis were attenuated by SiNOX4 compared to SiCon. Our study identified that HKMT-induced pleural fibrosis is mediated by NOX4–ERK–ROS via TLR4 and Angiotensin II receptor type1 (AT1R). There results suggest that NOX4 may be a novel therapeutic target for intervention in tuberculous pleural fibrosis.

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TMEM88 inhibits TGF-β1-induced-extracellular matrix (ECM) accumulation and epithelial-mesenchymal transition (EMT) program in human pleural mesothelial cells through modulating TGF-β1/Smad pathway

10.21203/rs.3.rs-22919/v1 ◽

2020 ◽

Author(s):

Zhongmin Sun ◽

Ning Qian ◽

Hong Li ◽

Tinghua Hu ◽

Ling Tang ◽

...

Keyword(s):

Extracellular Matrix ◽

Epithelial Mesenchymal Transition ◽

Mesothelial Cell ◽

Pathological Process ◽

Mesenchymal Transition ◽

Expression Levels ◽

Pleural Fibrosis ◽

Tgf Β1

Abstract Pleural fibrosis is an irreversible pathological process occurred in the development of several lung diseases. TMEM88 is a member of transmembrane (TMEM) family and has been found to be involved in the regulation of fibrogenesis. However, the role of TMEM88 in pleural fibrosis remains unknown. In this study, we aimed to explore the role of TMEM88 in pleural fibrosis in vitro using TGF-β1-induced human pleural mesothelial cell line MeT-5A cells. Our results showed that the expression levels of TMEM88 were downregulated in pleural fibrosis tissues and TGF-β1-treated Met-5A cells. Overexpression of TMEM88 inhibited the proliferation of Met-5A cells under TGF-β1 stimulation. In addition, TMEM88 overexpression prevented TGF-β1-induced extracellular matrix (ECM) accumulation and epithelial-mesenchymal transition (EMT) in Met-5A cells with decreased expression levels of Col I and fibronectin, increased levels of cytokeratin-8 and E-cadherin, as well as decreased levels of vimentin and α-SMA. Furthermore, overexpression of TMEM88 inhibited the expression of TGF-β receptor I (TβRI) and TβRII and suppressed the phosphorylation of Smad2 and Smad3 in Met-5A cells. In conclusion, these results indicated that TMEM88 exhibited an anti-fibrotic activity in pleural fibrosis via inhibiting the activation of TGF-β1/Smad signaling pathway.

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S100A4 amplifies TGF-β-induced epithelial–mesenchymal transition in a pleural mesothelial cell line

Journal of Investigative Medicine ◽

10.1136/jim-2017-000542 ◽

2017 ◽

Vol 66 (2) ◽

pp. 334-339 ◽

Cited By ~ 4

Author(s):

Qian Ning ◽

Feiyan Li ◽

Lei Wang ◽

Hong Li ◽

Yan Yao ◽

...

Keyword(s):

Transforming Growth Factor ◽

Epithelial Mesenchymal Transition ◽

Cell Model ◽

Mesothelial Cell ◽

Mesenchymal Cell ◽

Transforming Growth Factor Β ◽

Cell Marker ◽

Mesenchymal Transition ◽

Pleural Fibrosis ◽

S100a4 Expression

Pleural fibrosis can dramatically lower the quality of life. Numerous studies have reported that epithelial–mesenchymal transition (EMT) regulated by transforming growth factor-β (TGF-β) is involved in fibrosis. However, the molecular mechanism is inadequately understood. Fibroblast-specific protein-1 (S100A4) is a target of TGF-β signaling. In our previous study, we have reported that S100A4 is highly expressed in pleural fibrosis. Thus, we suggest that S100A4 took part in the TGF-β-induced EMT in pleural fibrosis. In this study, we determined the expression of S100A4 and EMT-related markers in Met-5A cells (pleural mesothelial cells) treated with TGF-β or TGF-β inhibitor by real-time PCR and western blot. In order to explore the role of S100A4, we used siRNA to knock down the expression of S100A4 in cell model. We found that the expression of epithelial cell marker was decreased and the mesenchymal cell marker increased with S100A4 upregulation after treatment with TGF-β. Moreover, the changes of EMT-related event were restricted when the expression of S100A4 was knocked down. Conversely, S100A4 can partially rescue the EMT-related expression changes induced by TGF-β inhibitor. These findings suggest that S100A4 expression is induced by the TGF-β pathway, and silencing S100A4 expression can inhibit the process of TGF-β-induced EMT.

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