scholarly journals TGF-β-induced α-SMA expression is mediated by C/EBPβ acetylation in human alveolar epithelial cells in vitro

2020 ◽  
Author(s):  
Hui Ding ◽  
Jinjun Chen ◽  
Jingping Qin ◽  
Ruhua Chen ◽  
Zili Yi

Abstract Background This study sought to determine whether binding of acetylated C/EBPβ to α-SMA promoter could affect its activity and was essential for EMT and extracellular matrix deposition in IPF using in vitro model. Methods Through western blotting, the expression of EMT and C/EBPβ were detected in A549 cells with TGF-β as pulmonary fibrotic model in vitro. Moreover, the expression of C/EBPβ mRNA via Real Time-PCR and Collagen-I expression using ELISA were performed. The luciferase activity assay was used to examine the activity of C/EBPβ. The knockdown expression of C/EBPβ gene was prepared in A549 cells with C/EBPβ siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using SIRT1. The binding ability of C/EBPβ with the α-SMA promoter was affirmed via ChIP and EMSA. Furthermore, the relationship between α-SMA and acetylated C/EBPβ was investigated using the co-immunoprecipitation. Results SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and the α-SMA promoter was dynamically monitored. Furthermore, it was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation. Conclusions Collectively, our data suggested that the EMT and fibrotic effect of TGF-β1 could be dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. This thus suggests that C/EBPβ acetylation may play a central role in pulmonary fibrosis.

2020 ◽  
Author(s):  
Hui Ding ◽  
Jinjun Chen ◽  
Jingping Qin ◽  
Ruhua Chen ◽  
Zili Yi

Abstract This study sought to determine whether binding of acetylated C/EBPβ to α-SMA promoter could affect its activity and was essential for EMT and extracellular matrix deposition in IPF using in vitro model. The expression of EMT and C/EBPβ in A549 cells with TGF-β as pulmonary fibrotic model were detected by western blotting and qPCR. Collagen-I expression using ELISA was performed. The luciferase activity was used to examine the activity of C/EBPβ. Knockdown of C/EBPβ was performed by siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using SIRT1. The binding ability of C/EBPβ with α-SMA promoter was affirmed via ChIP and EMSA. The relationship of α-SMA and acetylated C/EBPβ was investigated by Co-IP. SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and α-SMA promoter was dynamically monitored. It was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation. The EMT and fibrotic effect of TGF-β1 dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. C/EBPβ acetylation may play a central role in pulmonary fibrosis.


2021 ◽  
Author(s):  
Hui Ding ◽  
Jinjun Chen ◽  
Jingping Qin ◽  
Ruhua Chen ◽  
Zili Yi

Abstract Background: Although the morbidity and mortality rates associated with idiopathic pulmonary fibrosis (IPF) are high, there is still lack of powerful and precise therapeutic options for IPF. Object: Through in vitro model, this study sought to determine whether binding of acetylated CCAAT/enhancer binding protein β (C/EBPβ) to alpha-smooth muscle actin (α-SMA) promoter could affect the activity of the latter as well as assess if it is essential for epithelial-to-mesenchymal transition (EMT) and extracellular matrix deposition in IPF. Methods: The expression of EMT and C/EBPβ in A549 cells treated with transforming growth factor-beta (TGF-β) as pulmonary fibrotic model was detected by western blotting and qPCR. Collagen-I expression using ELISA was performed. The luciferase activity was used to examine the activity of C/EBPβ. Knockdown of C/EBPβ was performed by siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using sirtuin 1 (SIRT1). The binding ability of C/EBPβ with α-SMA promoter was affirmed via chromatin immunoprecipitation (ChIP) and electrophoresis mobility shift assay (EMSA). The relationship between α-SMA and acetylated C/EBPβ was determined with co-immunoprecipitation (Co-IP). SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and α-SMA promoter was dynamically monitored. Results: It was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation. Conclusion: The EMT and fibrotic effect of TGF-β1 is dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. Thus, C/EBPβ acetylation may play a central role in pulmonary fibrosis.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Hui Ding ◽  
Jinjun Chen ◽  
Jingping Qin ◽  
Ruhua Chen ◽  
Zili Yi

Abstract Background Although the morbidity and mortality rates associated with idiopathic pulmonary fibrosis (IPF) are high, there is still lack of powerful and precise therapeutic options for IPF. Object Through in vitro model, this study sought to determine whether binding of acetylated CCAAT/enhancer binding protein β (C/EBPβ) to alpha-smooth muscle actin (α-SMA) promoter could affect the activity of the latter as well as assess if it is essential for epithelial-to-mesenchymal transition (EMT) and extracellular matrix deposition in IPF. Methods The expression of EMT and C/EBPβ in A549 cells treated with transforming growth factor-beta (TGF-β) as pulmonary fibrotic model was detected by western blotting and qPCR. Collagen-I expression using ELISA was performed. The luciferase activity was used to examine the activity of C/EBPβ. Knockdown of C/EBPβ was performed by siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using sirtuin 1 (SIRT1). The binding ability of C/EBPβ with α-SMA promoter was affirmed via chromatin immunoprecipitation (ChIP) and electrophoresis mobility shift assay (EMSA). The relationship between α-SMA and acetylated C/EBPβ was determined with co-immunoprecipitation (Co-IP). SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and α-SMA promoter was dynamically monitored. Results It was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation. Conclusion The EMT and fibrotic effect of TGF-β1 is dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. Thus, C/EBPβ acetylation may play a central role in pulmonary fibrosis.


2021 ◽  
Author(s):  
Hui Ding ◽  
Jinjun Chen ◽  
Jingping Qin ◽  
Ruhua Chen ◽  
Zili Yi

Abstract Background: The morbidity and mortality rates associated with IPF are high, while powerful and precise therapeutic options with IPF are lacking. Object: Through in vitro model, this study sought to determine whether binding of acetylated CCAAT/enhancer binding protein β (C/EBPβ) to alpha-smooth muscle actin (α-SMA) promoter could affect the activity of the latter as well as assess if it is essential for epithelial-to-mesenchymal transition (EMT) and extracellular matrix deposition in idiopathic pulmonary fibrosis (IPF). Methods: The expression of EMT and C/EBPβ in A549 cells with transforming growth factor-beta (TGF-β) as pulmonary fibrotic model were detected by western blotting and qPCR. Collagen-I expression using ELISA was performed. The luciferase activity was used to examine the activity of C/EBPβ. Knockdown of C/EBPβ was performed by siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using sirtuin 1 (SIRT1). The binding ability of C/EBPβ with α-SMA promoter was affirmed via chromatin immunoprecipitation (ChIP) and electrophoresis mobility shift assay (EMSA). The relationship of α-SMA and acetylated C/EBPβ was investigated by co-immunoprecipitation (Co-IP). SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and α-SMA promoter was dynamically monitored. Results: It was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation. Conclusion: The EMT and fibrotic effect of TGF-β1 is dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. C/EBPβ acetylation may play a central role in pulmonary fibrosis.


2018 ◽  
Vol 16 (1) ◽  
pp. 407-414
Author(s):  
Rui-qin Li ◽  
Bai-yan Wang ◽  
Yu-wen Ding ◽  
Rui Zhang ◽  
Jun-xia Zhang ◽  
...  

AbstractThe present study explores the mechanism of resistance to pulmonary fibrosis by observing the possible effects of serum containing drugs prepared from Gua Lou Xie Bai decoction (GLXB-D) on transforming growth factor beta 1 (TGF-β1) induced Epithelial-mesenchymal transition (EMT) of A549 human alveolar epithelial cells. The inhibition rate was observed with the help of thiazolyl blue tetrazolium bromide (MTT) in 24 h and 48 h treated cells. Inverted microscope and transmission electron microscope (TEM) were used to study the changes in the morphology and ultrastructure of the cells. The expressions of E-cadherin and Vimentin were comparatively analyzed by Western blotting, while the expressions of Collagen I and III were analyzed by ELISA. The data obtained indicated that the expression of epithelial marker E-cadherin was decreased, while the expressions of EMT markers such as Vimentin and Collagen I and III were increased in 24 h after TGF-β1 induction. However, the serum containing drugs of GLXB-D were found to inhibit the TGF-β1 induced proliferation of cells, increase the expression of E-cadherin and decrease the expression of Vimentin, collagen I and III. In conclusion, the serum containing drugs of GLXB-D effectively reduced pulmonary fibrosis, mainly via the reversal of EMT induction by TGF-β1. Thus, it can be considered as a potential candidate for the development of better treatment methods for pulmonary fibrosis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaohe Li ◽  
Rui Liu ◽  
Yunyao Cui ◽  
Jingjing Liang ◽  
Zhun Bi ◽  
...  

Pulmonary fibrosis is a known sequela of severe or persistent lung damage. Existing clinical, imaging and autopsy studies have shown that the lungs exhibit a pathological pulmonary fibrosis phenotype after infection with coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pulmonary fibrosis may be one of the most serious sequelae associated with coronavirus disease 2019 (COVID-19). In this study, we aimed to examine the preventative effects of the antiviral drug remdesivir on pulmonary fibrosis. We used a mouse model of bleomycin-induced pulmonary fibrosis to evaluate the effects of remdesivir on pulmonary fibrosis in vivo and further explored the potential pharmacological mechanisms of remdesivir in lung fibroblasts and alveolar epithelial cells in vitro. The preventive remdesivir treatment was started on the day of bleomycin installation, and the results showed that remdesivir significantly alleviated bleomycin-induced collagen deposition and improved pulmonary function. In vitro experiments showed that remdesivir dose-dependently suppressed TGF-β1-induced lung fibroblast activation and improved TGF-β1-induced alveolar epithelial to mesenchymal transition. Our results indicate that remdesivir can preventatively alleviate the severity of pulmonary fibrosis and provide some reference for the prevention of pulmonary fibrosis in patients with COVID-19.


2006 ◽  
Vol 291 (2) ◽  
pp. L166-L174 ◽  
Author(s):  
Ryan M. McAdams ◽  
Shamimunisa B. Mustafa ◽  
Jeffrey S. Shenberger ◽  
Patricia S. Dixon ◽  
Barbara M. Henson ◽  
...  

The treatment of severe lung disease often requires the use of high concentrations of oxygen coupled with the need for assisted ventilation, potentially exposing the pulmonary epithelium to both reactive oxygen species and nonphysiological cyclic stretch. Whereas prolonged hyperoxia is known to cause increased cell injury, cyclic stretch may result in either cell proliferation or injury depending on the pattern and degree of exposure to mechanical deformation. How hyperoxia and cyclic stretch interact to affect the pulmonary epithelium in vitro has not been previously investigated. This study was performed using human alveolar epithelial A549 cells to explore the combined effects of cyclic stretch and hyperoxia on cell proliferation and viability. Under room air conditions, cyclic stretch did not alter cell viability at any time point and increased cell number after 48 h compared with unstretched controls. After exposure to prolonged hyperoxia, cell number and [3H]thymidine incorporation markedly decreased, whereas evidence of oxidative stress and nonapoptotic cell death increased. The combination of cyclic stretch with hyperoxia significantly mitigated the negative effects of prolonged hyperoxia alone on measures of cell proliferation and viability. In addition, cyclic stretch resulted in decreased levels of oxidative stress over time in hyperoxia-exposed cells. Our results suggest that cyclic stretch, as applied in this study, can minimize the detrimental effects of hyperoxia on alveolar epithelial A549 cells.


2021 ◽  
Vol 22 (20) ◽  
pp. 11152
Author(s):  
Kai-Wei Chang ◽  
Xiang Zhang ◽  
Shih-Chao Lin ◽  
Yu-Chao Lin ◽  
Chia-Hsiang Li ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is characterized by fibrotic change in alveolar epithelial cells and leads to the irreversible deterioration of pulmonary function. Transforming growth factor-beta 1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in type 2 lung epithelial cells contributes to excessive collagen deposition and plays an important role in IPF. Atractylodin (ATL) is a kind of herbal medicine that has been proven to protect intestinal inflammation and attenuate acute lung injury. Our study aimed to determine whether EMT played a crucial role in the pathogenesis of pulmonary fibrosis and whether EMT can be utilized as a therapeutic target by ATL treatment to mitigate IPF. To address this topic, we took two steps to investigate: 1. Utilization of anin vitro EMT model by treating alveolar epithelial cells (A549 cells) with TGF-β1 followed by ATL treatment for elucidating the underlying pathways, including Smad2/3 hyperphosphorylation, mitogen-activated protein kinase (MAPK) pathway overexpression, Snail and Slug upregulation, and loss of E-cadherin. Utilization of an in vivo lung injury model by treating bleomycin on mice followed by ATL treatment to demonstrate the therapeutic effectiveness, such as, less collagen deposition and lower E-cadherin expression. In conclusion, ATL attenuates TGF-β1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in mice.


Author(s):  
Guo-Ping Xu ◽  
Qing-Quan Li ◽  
Xi-Xi Cao ◽  
Qi Chen ◽  
Zhong-Hua Zhao ◽  
...  

AbstractThe aim of this study was to investigate whether transforming growth factor-β1 (TGF-β1) could induce alveolar epithelial-mesenchymal transition (EMT) in vitro, and whether Smad7 gene transfer could block this transition. We also aimed to elucidate the possible mechanisms of these processes. The Smad7 gene was transfected to the rat type II alveolar epithelial cell line (RLE-6TN). Expression of the EMT-associated markers was assayed by Western Blot and Real-time PCR. Morphological alterations were examined via phase-contrast microscope and fluorescence microscope, while ultrastructural changes were examined via electron microscope. TGF-β1 treatment induced a fibrotic phenotype of RLE-6TN with increased expression of fibronectin (FN), α-smooth muscle actin (α-SMA) and vimentin, and decreased expression of E-cadherin (E-cad) and cytokeratin19 (CK19). After transfecting the RLE-6TN with the Smad7 gene, the expression of the mesenchymal markers was downregulated while that of the epithelial markers was upregulated. TGF-β1 treatment for 48 h resulted in the separation of RLE-6TN from one another and a change into elongated, myofibroblast-like cells. After the RLE-6TN had been transfected with the Smad7 gene, TGF-β1 treatment had no effect on the morphology of the RLE-6TN. TGF-β1 treatment for 48 h resulted in an abundant expression of α-SMA in the RLE-6TN. If the RLE-6TN were transfected with the Smad7 gene, TGF-β1 treatment for 48 h could only induce a low level of α-SMA expression. Furthermore, TGF-β1 treatment for 12 h resulted in the degeneration and swelling of the osmiophilic multilamellar bodies, which were the markers of type II alveolar epithelial cells. TGF-β1 can induce alveolar epithelialmesenchymal transition in vitro, which is dependent on the Smads signaling pathway to a certain extent. Overexpression of the Smad7 gene can partially block this process


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