scholarly journals Thymosin β4 Protect Against LPS Induced Lung Injury and Inflammation and Subsequent Fibrosis in Mice

Author(s):  
Zhen Tian ◽  
Naijuan Yao ◽  
Yuchao Wu ◽  
Fei Wang

Abstract Background: Inflammation plays a critical role in the progress ion of pulmonary fibrosis. Thymosin β4 (Tβ4) has antioxidant, anti-inflammatory and antifibrotic effects. Although the potent protective role of Tβ4 in bleomycin-induced pulmonary fibrosis has been validated, the mechanism is not clear, and its impact on LPS-induced lung injury/fibrosis has not been reported. Method: Expression of Tβ4 in fibrotic lung tissues was assessed by real-time quantitative reverse transcriptase PCR (RQ-PCR), immunohistochemistry (IHC) and Western Blotting. The effects of intraperitoneal adeno-associated virus-Tβ4 (AAV-Tβ4) on LPS-induced lung injury and fibrosis were observed through the evaluation of collagen deposition and α-SMA expression. In vitro tests with HPAEpiC and HLF-1 cells were performed to confirm the effects of Tβ4.Results: In this study, we evaluated the role of Tβ4 on pulmonary fibrosis and explored the possible underlying mechanisms. We found that Tβ4 was markedly upregulated in human or mouse fibrotic lung tissues. Adeno-associated virus-Tβ4 (AAV-Tβ4) markedly alleviated LPS-induced oxidative damage, lung injury, inflammation and fibrosis in mice. Our in vitro experiments also showed that LPS inhibited mitophagy and promoted inflammation via oxidative stress in HPAEpiC, and usage of Tβ4 significantly attenuated LPS-induced mitophagy inhibition, inflammasome activation and TGF-β1 induced epithelial-mesenchymal transition (EMT) in HPAEpiC. Moreover, we found that Tβ4 suppressed the proliferation and attenuated the TGF-β1-induced activation of HLF-1 cells. Conclusions: In conclusion, Tβ4 alleviated LPS-induced lung injury, inflammation, and subsequent fibrosis in mice, suggesting a protective role of Tβ4 in disease pathogenesis of pulmonary fibrosis (PF). Tβ4 may involve attenuating oxidative injury, promoting mitophagy, and then alleviating inflammation and fibrosis. Modulating of Tβ4 may be novel strategies for treating PF.

2021 ◽  
Author(s):  
Zhen Tian ◽  
Naijuan Yao ◽  
Fei Wang ◽  
Litao Ruan

Abstract Background: Inflammation plays a critical role in the progression of pulmonary fibrosis. Thymosin β4 (Tβ4) has antioxidant, anti-inflammatory and antifibrotic effects. Although the potent protective role of Tβ4 in bleomycin-induced pulmonary fibrosis has been validated, the mechanism is not clear, and its impact on lipopolysaccharide (LPS)-induced lung injury/fibrosis has not been reported. Method: Expression of Tβ4 in fibrotic lung tissues was assessed by real-time quantitative reverse transcriptase PCR (RQ-PCR), immunohistochemistry (IHC) and Western Blotting. The effects of intraperitoneal adeno-associated virus-Tβ4 (AAV-Tβ4) on LPS-induced lung injury and fibrosis were observed through the evaluation of collagen deposition and α-smooth muscle actin (SMA) expression. In vitro tests with HPAEpiC and HLF-1 cells were performed to confirm the effects of Tβ4.Results: In this study, we evaluated the role of Tβ4 in pulmonary fibrosis and explored the possible underlying mechanisms. We found that Tβ4 was markedly upregulated in human or mouse fibrotic lung tissues. AAV-Tβ4 markedly alleviated LPS-induced oxidative damage, lung injury, inflammation, and fibrosis in mice. Our in vitro experiments also showed that LPS inhibited mitophagy and promoted inflammation via oxidative stress in HPAEpiC, and usage of Tβ4 significantly attenuated LPS-induced mitophagy inhibition, inflammasome activation and transforming growth factor-β (TGF)-β1 induced epithelial-mesenchymal transition (EMT) in HPAEpiC. Moreover, we found that Tβ4 suppressed the proliferation and attenuated the TGF-β1-induced activation of HLF-1 cells. Conclusions: In conclusion, Tβ4 alleviates LPS-induced lung injury, inflammation, and subsequent fibrosis in mice, suggesting a protective role of Tβ4 in disease pathogenesis of pulmonary fibrosis (PF). Tβ4 involves in attenuating oxidative injury, promoting mitophagy, and then alleviating inflammation and fibrosis. Modulating of Tβ4 might be a novel strategy for treating PF.


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.


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.


2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Chang-Mei Weng ◽  
Qing Li ◽  
Kui-Jun Chen ◽  
Cheng-Xiong Xu ◽  
Meng-Sheng Deng ◽  
...  

Abstract Idiopathic pulmonary fibrosis (IPF) is a fatal and chronic disease with a high rate of infection and mortality; however, its etiology and pathogenesis remain unclear. Studies have revealed that epithelial–mesenchymal transition (EMT) is a crucial cellular event in IPF. Here, we identified that the pulmonary fibrosis inducer bleomycin simultaneously increased the expression of bFGF and TGF-β1 and inhibited epithelial-specific regulatory protein (ESRP1) expression in vivo and in vitro. In addition, in vitro experiments showed that bFGF and TGF-β1 down-regulated the expression of ESRP1 and that silencing ESRP1 promoted EMT in A549 cells. Notably, we determined that bFGF activates PI3K/Akt signaling, and treatment with the PI3K/Akt inhibitor LY294002 inhibited bleomycin-induced cell morphology changes and EMT. In addition, the effects of LY294002 on bleomycin-induced EMT were inhibited by ESRP1 silencing in A549 cells. Taken together, these findings suggest that bleomycin induced EMT through down-regulating ESRP1 by simultaneously increasing bFGF and TGF-β1 in pulmonary fibrosis. Additionally, our findings indicated that bFGF inhibits ESRP1 by activating PI3K/Akt signaling.


2020 ◽  
Vol 15 (8) ◽  
pp. 1934578X2094835
Author(s):  
Wenyue Zhuang ◽  
Na Zhao ◽  
Di Li ◽  
Xiaoming Su ◽  
Yueyang Wang ◽  
...  

There is no effective method for treating pulmonary fibrosis (PF) until now. This study investigated the anti-fibrotic effect of schisantherin A (SCA) extracted from Schisandra chinensis and its potential molecular mechanism in PF. A bleomycin-induced PF mouse model in vivo and transforming growth factor (TGF)-β1-induced A549 epithelial-mesenchymal transition (EMT) cell model in vitro were used for assessing the anti-fibrotic effect of SCA. Histopathological examination was conducted after hematoxylin and eosin and Masson staining. The level of TGF-β1 was tested by ELISA. The expression levels of α-smooth muscle actin, E-cadherin, and inflammatory cytokines (COX2, IL-1β, IL-6, and TNF-α) were determined by quantitative reverse transcription polymerase chain reaction and Western blot. The expression of extracellular signal-regulated kinase (ERK) was tested in lung tissues and cells by Western blot. The in vivo experiments revealed that SCA treatment markedly improved body weight and pulmonary index and reformed the destruction of the lung tissue structure. We observed that SCA inhibited the process of TGF-β1-induced EMT in the in vitro experiments. Inflammatory cytokines were reduced greatly in lung tissues and cells by SCA. Our study also indicated that SCA decreased phosphorylated ERK. It was concluded that SCA can attenuate PF by regulating the ERK signaling pathway, which suggests that SCA may be used as a potential therapeutic drug for PF.


Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 122 ◽  
Author(s):  
Xiu He ◽  
Shi Chen ◽  
Chao Li ◽  
Jiaqi Ban ◽  
Yungeng Wei ◽  
...  

Silicosis is an occupational lung disease characterized by persistent inflammation and irreversible fibrosis. Crystalline silica (CS) particles are mainly phagocytized by alveolar macrophages (AMs), which trigger apoptosis, inflammation, and pulmonary fibrosis. Previously, we found that autophagy-lysosomal system dysfunction in AMs was involved in CS-induced inflammation and fibrosis. Induction of autophagy and lysosomal biogenesis by transcription factor EB (TFEB) nuclear translocation can rescue fibrotic diseases. However, the role of TFEB in silicosis is unknown. In this study, we found that CS induced TFEB nuclear localization and increased TFEB expression in macrophages both in vivo and in vitro. However, TFEB overexpression or treatment with the TFEB activator trehalose (Tre) alleviated lysosomal dysfunction and enhanced autophagic flux. It also reduced apoptosis, inflammatory cytokine levels, and fibrosis. Both pharmacologically inhibition of autophagy and TFEB knockdown in macrophages significantly abolished the antiapoptotic and anti-inflammatory effects elicited by either TFEB overexpression or Tre treatment. In conclusion, these results uncover a protective role of TFEB-mediated autophagy in silicosis. Our study suggests that restoration of autophagy-lysosomal function by Tre-induced TFEB activation may be a novel strategy for the treatment of silicosis.


2017 ◽  
Vol 47 ◽  
pp. 38-46 ◽  
Author(s):  
Lijun Tao ◽  
Juan Cao ◽  
Wencheng Wei ◽  
Haifeng Xie ◽  
Mian Zhang ◽  
...  

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.


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