scholarly journals Thymosin β4 protect against LPS induced lung injury and inflammation and subsequent fibrosis in mice

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 ◽  
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 ◽  
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.


2007 ◽  
Vol 293 (3) ◽  
pp. L525-L534 ◽  
Author(s):  
Brigham C. Willis ◽  
Zea Borok

Epithelial-mesenchymal transition (EMT), a process whereby fully differentiated epithelial cells undergo transition to a mesenchymal phenotype giving rise to fibroblasts and myofibroblasts, is increasingly recognized as playing an important role in repair and scar formation following epithelial injury. The extent to which this process contributes to fibrosis following injury in the lung is a subject of active investigation. Recently, it was demonstrated that transforming growth factor (TGF)-β induces EMT in alveolar epithelial cells (AEC) in vitro and in vivo, and epithelial and mesenchymal markers have been colocalized to hyperplastic type II (AT2) cells in lung tissue from patients with idiopathic pulmonary fibrosis (IPF), suggesting that AEC may exhibit extreme plasticity and serve as a source of fibroblasts and/or myofibroblasts in lung fibrosis. In this review, we describe the characteristic features of EMT and its mechanistic underpinnings. We further describe the contribution of EMT to fibrosis in adult tissues following injury, focusing especially on the critical role of TGF-β and its downstream mediators in this process. Finally, we highlight recent descriptions of EMT in the lung and the potential implications of this process for the treatment of fibrotic lung disease. Treatment for fibrosis of the lung in diseases such as IPF has heretofore focused largely on amelioration of potential inciting processes such as inflammation. It is hoped that this review will stimulate further consideration of the cellular mechanisms of fibrogenesis in the lung and especially the role of the epithelium in this process, potentially leading to innovative avenues of investigation and treatment.


2017 ◽  
Vol 312 (4) ◽  
pp. F760-F768 ◽  
Author(s):  
Chen Ye ◽  
Hui Tang ◽  
Zheng Zhao ◽  
Chun-Tao Lei ◽  
Chao-Qun You ◽  
...  

It is well recognized that murine double minute gene 2 (MDM2) plays a critical role in cell proliferation and inflammatory processes during tumorigenesis. It is also reported that MDM2 is expressed in glomeruli and involved in podocyte injury. However, whether MDM2 is implicated in renal fibrosis remains unclear. Here we investigated the role of MDM2 in tubulointerstitial fibrosis (TIF). By immunohistochemical staining and Western blotting we confirmed that MDM2 is upregulated in the tubulointerstitial compartment in patients with TIF and unilateral urethral obstruction (UUO) mice, which mainly originates from myofibroblasts. Consistently, in vitro MDM2 is increased in TGF-β1-treated fibroblasts, one of the major sources of collagen-producing myofibroblasts during TIF, along with fibroblast activation. Importantly, genetic deletion of MDM2 significantly attenuates fibroblast activation. We then analyzed the possible downstream signaling of MDM2 during fibroblast activation. p53-dependent pathway is the classic downstream signaling of MDM2, and Nutlin-3 is a small molecular inhibitor of MDM2-p53 interaction. To our surprise, Nutlin-3 could not ameliorate fibroblast activation in vitro and TIF in UUO mice. However, we found that Notch1 signaling is attenuated during fibroblast activation, which could be markedly rescued by MDM2 knockdown. Overexpression of intracellular domain of Notch1 (NICD) by plasmid could obviously minimize fibroblast activation induced by TGF-β1. In addition, the degradation of NICD is strikingly suppressed by PYR-41, an inhibitor of ubiquitin-activating enzyme E1, and proteasome inhibitor MG132. Taken together, our findings provide the first evidence that MDM2 is involved in fibroblast activation and TIF, which associates with Notch1 ubiquitination and proteasome degradation.


2020 ◽  
Author(s):  
Yi Duan ◽  
Zhifeng Gao ◽  
Xiaoyu Wang ◽  
Yuanyuan Meng ◽  
Huan Zhang

Abstract Background: Maintenance of the function and survival of liver sinusoidal endothelial cells (LSECs) play a crucial role in hepatic ischemia/reperfusion (I/R) injury, a major cause of liver impairment during surgical treatment. Emerging evidence indicate a critical role of microRNAs in I/R injury. This study aims to investigate whether miR-9-5p exert a protective effect on LSECs in vitro .Methods: We transfected LSECs with miR-9-5p mimic or mimic NC. LSECs were treated with oxygen and glucose deprivation (OGD, 5% CO2 and 95% N2), followed by glucose-free DMEM medium for 6 h, and high-glucose (HG, 30 mmol/L glucose) DMEM medium for 12 h. The biological role of miR-9-5p in I/R-induced LSEC injury was determined. Results: In the in vitro model of OGD/HG injury in LSECs, the expression levels of miR-9-5p were significantly downregulated and those of CXC chemokine receptor-4 (CXCR4) upregulated. LSEC I/R injury led to deteriorated cell death, enhanced oxidative stress and excessive inflammatory response. Mechanistically, we showed that miR-9-5p overexpression significantly upregulated both mRNA and protein levels of CXCR4, followed by rescue of LSECs, ameliorated inflammatory response, and deactivation of pro-apoptotic signaling pathways.Conclusion: miR-9-5p promotes LSEC survival and inhibits apoptosis and inflammatory response in LSECs following OGD/HG injury via downregulation of CXCR4.


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.


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