scholarly journals Fibroblast Growth Factor 2 Augments Transforming Growth Factor Beta 1 in Inducing Epithelial-Mesenchymal Transition in Human Lung Epithelial Cells

2019 ◽  
Author(s):  
Lamis M.F. El-Baz ◽  
Nahla M. Shoukry ◽  
Mohamed L. Salem ◽  
Hani S. Hafez ◽  
Robert D. Guzy

Abstract Background: Epithelial-mesenchymal transition (EMT) is a critical event in wound healing and tissue repair following injury. Transforming growth factor beta-1 (TGFβ1) plays an important role in inducing EMT in lung epithelial cells in vitro and in vivo. As fibroblast growth factor-2 (FGF2) reverses TGFβ1-induced collagen I (COL1A1) and α-smooth muscle actin (Actin alpha 2; ACTA2) expression in primary mouse and human lung fibroblasts, we set out this study to determine the effect of FGF2 on TGFβ1-induced EMT in human lung epithelial cells. Methods: BEAS-2B and A549 cells were treated with recombinant FGF2 (2 nM) with or without TGFβ1 (2 ng/ml) for up to 4 days. The phenotypic alterations associated with EMT were assessed by quantitative real-time PCR and E-cadherin protein expression levels was assayed by western blot and immunofluorescence staining. Cell migration was confirmed using wound-healing assay. Results: TGFβ1 treatment led to significantly reduced expression of E-cadherin (CDH1) and markedly induced expression of mesenchymal proteins such as N-cadherin (CDH2), tenascin C (TNC), fibronectin (FN), ACTA2 and COL1A1. TGFβ1 also induced a morphological change and a significant increase in cell migration. FGF2 did not significantly alter EMT gene expression markers on its own, however enhanced TGFβ1-induced suppression of CDH1 and upregulation of ACTA2, but did not alter TNC, FN and CDH2 gene expression levels induced by TGFβ1. FGF2 maintained TGFβ1-induced morphologic changes as well as increased the migration of TGFβ1-treated cells. Furthermore, FGF2 treatment significantly inhibited TGFβ1-induced COL1A1 expression in both BEAS-2B and A549 cells. FGFR-specific tyrosine kinase inhibitor PD173074 blocked the synergism between these two growth factors. Conclusions: This study suggests a synergistic effect between TGFβ1 and FGF2 in inducing EMT, which may play an important role in wound healing and tissue repair after injury. Our findings provide insight into the effects of FGF2 following lung injury and in pulmonary fibrosis.

2020 ◽  
Author(s):  
Lamis M.F. El-Baz ◽  
Nahla M. Shoukry ◽  
Mohamed L. Salem ◽  
Hani S. Hafez ◽  
Robert D. Guzy

Abstract The authors have withdrawn the journal submission associated with this preprint and requested that the preprint also be withdrawn.


2020 ◽  
Vol 21 (23) ◽  
pp. 9084
Author(s):  
Shu-Ching Ou ◽  
Kuan-Jen Bai ◽  
Wun-Hao Cheng ◽  
Jing-Yun Chen ◽  
Chien-Huang Lin ◽  
...  

Background: Lung epithelial cells play critical roles in idiopathic pulmonary fibrosis. Methods: In the present study, we investigated whether transforming growth factor-β (TGF-β)-induced expression of connective tissue growth factor (CTGF) was regulated by the extracellular signal-regulated kinase (ERK)/a disintegrin and metalloproteinase 17 (ADAM17)/ribosomal S6 kinases 1 (RSK1)/CCAAT/enhancer-binding protein β (C/EBPβ) signaling pathway in human lung epithelial cells (A549). Results: Our results revealed that TGF-β-induced CTGF expression was weakened by ADAM17 small interfering RNA (ADAM17 siRNA), TNF-α processing inhibitor-0 (TAPI-0, an ADAM17 inhibitor), U0126 (an ERK inhibitor), RSK1 siRNA, and C/EBPβ siRNA. TGF-β-induced ERK phosphorylation as well as ADAM17 phosphorylation was attenuated by U0126. The TGF-β-induced increase in RSK1 phosphorylation was inhibited by TAPI-0 and U0126. TGF-β-induced C/EBPβ phosphorylation was weakened by U0126, ADAM17 siRNA, and RSK1 siRNA. In addition, TGF-β increased the recruitment of C/EBPβ to the CTGF promoter. Furthermore, TGF-β enhanced fibronectin (FN), an epithelial–mesenchymal transition (EMT) marker, and CTGF mRNA levels and reduced E-cadherin mRNA levels. Moreover, TGF-β-stimulated FN protein expression was reduced by ADAM17 siRNA and CTGF siRNA. Conclusion: The results suggested that TGF-β induces CTGF expression through the ERK/ADAM17/RSK1/C/EBPβ signaling pathway. Moreover, ADAM17 and CTGF participate in TGF-β-induced FN expression in human lung epithelial cells.


Author(s):  
Lamis M.F. El-Baz ◽  
Nahla M. Shoukry ◽  
Hani S. Hafez ◽  
Robert D. Guzy ◽  
Mohamed Labib Salem

Impaired lung epithelial cell regeneration following injury may contribute to the development of pulmonary fibrosis. Epithelial-mesenchymal transition (EMT) is a critical event in embryonic development, wound healing following injury, and even cancer progression. Previous studies have shown that the combination of transforming growth factor beta-1 (TGFβ1) and fibroblast growth factor 2 (FGF2) induces EMT during cancer metastasis. However, this synergy remains to be elucidated in inducing EMT associated with wound healing after injury. We set out this study to determine the effect of fibroblast growth factor 2 (FGF2) on TGFβ1-induced EMT in the human lung epithelium. BEAS-2B and A549 cells were treated with TGFβ1, FGF2, or both. EMT phenotype was investigated morphologically and by measuring mRNA expression levels; using quantitative real-time PCR. E-cadherin expression was assayed by western blot and immunofluorescence staining. Cell migration was confirmed using a wound-healing assay. TGFβ1 induced a morphological change and a significant increase in cell migration of BEAS-2B cells. TGFβ1 significantly reduced E-cadherin (CDH1) mRNA expression and markedly induced expression of N-cadherin (CDH2), tenascin C (TNC), fibronectin (FN), actin alpha 2 (ACTA2), and collagen I (COL1A1). While FGF2 alone did not significantly alter EMT gene expression, it enhanced TGFβ1-induced suppression of CDH1 and upregulation of ACTA2, but not TNC, FN, and CDH2. FGF2 significantly inhibited TGFβ1-induced COL1A1 expression. Furthermore, FGF2 maintained TGFβ1-induced morphologic changes and increased the migration of TGFβ1-treated cells. This study suggests a synergistic effect between TGFβ1 and FGF2 in inducing EMT in lung epithelial cells, which may play an important role in wound healing and tissue repair after injury.


2018 ◽  
Vol 46 (5) ◽  
pp. 1821-1834 ◽  
Author(s):  
Daishun Liu ◽  
Honglan Zhu ◽  
Ling Gong ◽  
Shenglan Pu ◽  
Yang Wu ◽  
...  

Background/Aims: Epithelial to mesenchymal transition (EMT) is a crucial process involved in pulmonary fibrosis. This study aimed to explore the role of histone deacetylases (HDACs) and endoplasmic reticulum (ER) stress in EMT in human lung epithelial cells. Methods: Human lung adenocarcinoma A549 cells were treated with bleomycin and tunicamycin to induce EMT. The proliferation of A549 cells was detected by MTT assay. The expression of HDACs and EMT markers was detected by PCR and Western blot analysis. The secretion of TGF-β1 and collagen I was examined by ELISA. Results: A549 cells switched from a cobblestone-like appearance to an elongated fibroblast like appearance after exposure to tunicamycin or bleomycin, accompanied by increased expression of N-cadherin, α-SMA and Collagen I. Meanwhile, GRP78 was upregulated in A549 cells exposed to tunicamycin or bleomycin. These changes induced by tunicamycin or bleomycin could be abrogated by 4-PBA. Moreover, tunicamycin and bleomycin promoted the expression of HDAC2 and HDAC6, and HDACs inhibitor SAHA abrogated the morphological and biochemical changes in A549 cells. 4-PBA and SAHA inhibited the upregulation of pulmonary fibrosis factors TGF-β1 and IL-32 and the activation of Smad pathway induced by tunicamycin or bleomycin. Conclusions: We provide the first evidence that tunicamycin and bleomycin induce ER stress and EMT in lung epithelial cells via the upregulation of HDACs. HDACs inhibitor could inhibit ER stress induced upregulation of pulmonary fibrosis factors and the activation of Smad pathway. HDACs inhibitors are promising agents for the therapy of pulmonary fibrosis.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2639
Author(s):  
Frauke Stanke ◽  
Sabina Janciauskiene ◽  
Stephanie Tamm ◽  
Sabine Wrenger ◽  
Ellen Luise Raddatz ◽  
...  

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is influenced by the fundamental cellular processes like epithelial differentiation/polarization, regeneration and epithelial–mesenchymal transition. Defects in CFTR protein levels and/or function lead to decreased airway surface liquid layer facilitating microbial colonization and inflammation. The SERPINA1 gene, encoding alpha1-antitrypsin (AAT) protein, is one of the genes implicated in CF, however it remains unknown whether AAT has any influence on CFTR levels. In this study we assessed CFTR protein levels in primary human lung epithelial cells grown at the air-liquid-interface (ALI) alone or pre-incubated with AAT by Western blots and immunohistochemistry. Histological analysis of ALI inserts revealed CFTR- and AAT-positive cells but no AAT-CFTR co-localization. When 0.5 mg/mL of AAT was added to apical or basolateral compartments of pro-inflammatory activated ALI cultures, CFTR levels increased relative to activated ALIs. This finding suggests that AAT is CFTR-modulating protein, albeit its effects may depend on the concentration and the route of administration. Human lung epithelial ALI cultures provide a useful tool for studies in detail how AAT or other pharmaceuticals affect the levels and activity of CFTR.


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