scholarly journals Prostaglandin E2 protects murine lungs from bleomycin-induced pulmonary fibrosis and lung dysfunction

2011 ◽  
Vol 301 (5) ◽  
pp. L645-L655 ◽  
Author(s):  
Ryan T. Dackor ◽  
Jennifer Cheng ◽  
James W. Voltz ◽  
Jeffrey W. Card ◽  
Catherine D. Ferguson ◽  
...  

Prostaglandin E2 (PGE2) is a lipid mediator that is produced via the metabolism of arachidonic acid by cyclooxygenase enzymes. In the lung, PGE2 acts as an anti-inflammatory factor and plays an important role in tissue repair processes. Although several studies have examined the role of PGE2 in the pathogenesis of pulmonary fibrosis in rodents, results have generally been conflicting, and few studies have examined the therapeutic effects of PGE2 on the accompanying lung dysfunction. In this study, an established model of pulmonary fibrosis was used in which 10–12-wk-old male C57BL/6 mice were administered a single dose (1.0 mg/kg) of bleomycin via oropharyngeal aspiration. To test the role of prostaglandins in this model, mice were dosed, via surgically implanted minipumps, with either vehicle, PGE2 (1.32 μg/h), or the prostacyclin analog iloprost (0.33 μg/h) beginning 7 days before or 14 days after bleomycin administration. Endpoints assessed at 7 days after bleomycin administration included proinflammatory cytokine levels and measurement of cellular infiltration into the lung. Endpoints assessed at 21 days after bleomycin administration included lung function assessment via invasive (FlexiVent) analysis, cellular infiltration, lung collagen content, and semiquantitative histological analysis of the degree of lung fibrosis (Ashcroft method). Seven days after bleomycin administration, lymphocyte numbers and chemokine C-C motif ligand 2 expression were significantly lower in PGE2- and iloprost-treated animals compared with vehicle-treated controls ( P < 0.05). When administered 7 days before bleomycin challenge, PGE2 also protected against the decline in lung static compliance, lung fibrosis, and collagen production that is associated with 3 wk of bleomycin exposure. However, PGE2 had no therapeutic effect on these parameters when administered 14 days after bleomycin challenge. In summary, PGE2 prevented the decline in lung static compliance and protected against lung fibrosis when it was administered before bleomycin challenge but had no therapeutic effect when administered after bleomycin challenge.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Panpan Liu ◽  
Lei Zhao ◽  
Yuxia Gu ◽  
Meilan Zhang ◽  
Hongchang Gao ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung diseases with a poor prognosis. Long non-coding RNAs (lncRNAs) have been reported to be involved in IPF in several studies. However, the role of lncRNA SNHG16 in IPF is largely unknown. Methods Firstly, experimental pulmonary fibrosis model was established by using bleomycin (BML). Histology and Western blotting assays were used to determine the different stages of fibrosis and expression of several fibrosis biomarkers. The expression of SNHG16 was detected by quantitative real-time polymerase chain reaction (qRT‐PCR). EdU staining and wound-healing assay were utilized to analyze proliferation and migration of lung fibroblast cells. Molecular mechanism of SNHG16 was explored by bioinformatics, dual-luciferase reporter assay, RNA immunoprecipitation assay (RIP), and qRT-PCR. Results The expression of SNHG16 was significantly up-regulated in bleomycin-(BLM) induced lung fibrosis and transforming growth factor-β (TGF-β)-induced fibroblast. Knockdown of SNHG16 could attenuate fibrogenesis. Mechanistically, SNHG16 was able to bind and regulate the expression of miR-455-3p. Moreover, SNHG16 also regulated the expression of Notch2 by targeting miR-455-3p. Finally, SNHG16 could promote fibrogenesis by regulating the expression of Notch2. Conclusion Taken together, our study demonstrated that SNHG16 promoted pulmonary fibrosis by targeting miR-455-3p to regulate the Notch2 pathway. These findings might provide a novel insight into pathologic process of lung fibrosis and may provide prevention strategies in the future.


2019 ◽  
Vol 38 (7) ◽  
pp. 794-802 ◽  
Author(s):  
G Xu ◽  
X Wang ◽  
H Yu ◽  
C Wang ◽  
Y Liu ◽  
...  

Paraquat (PQ) is a highly toxic herbicide to humans. Pulmonary fibrosis is one of the most typical features of PQ poisoning, which develops from several days to weeks after ingestion. However, the mechanism of fibrosis is still unclear. In this study, we aimed to determine expressions of autophagy-related markers Beclin 1, microtubule-associated protein light chain 3 (LC3), and p62 in PQ-poisoned lungs and to explore the role of autophagy in pulmonary fibrosis induced by PQ. We detected markers of lung fibrosis and expressions of autophagy-related protein in the specimens from eight fatal cases of PQ poisoning by hematoxylin and eosin staining, Masson’s trichrome staining, and immunohistochemistry. Based on the staining results of lung fibrosis, these cases were divided into two groups, fibrosis and non-fibrosis groups. The correlation between autophagy protein expressions and pulmonary fibrosis was examined. The results demonstrated that the autophagy-related proteins were significantly expressed in fibrosis group compared with the non-fibrosis group. There was a significantly positive correlation between these protein expressions and severity of lung fibrosis. In conclusion, autophagy dysfunction may be involved in lung fibrogenesis caused by PQ poisoning. This may be a promising clue for understanding the molecular mechanism underlying PQ-induced lung fibrosis and provide evidence for treating fibrosis by regulating the level of autophagy.


2018 ◽  
Vol 315 (4) ◽  
pp. L563-L575 ◽  
Author(s):  
Hua Jiang ◽  
Yingzhun Chen ◽  
Tong Yu ◽  
Xiaoguang Zhao ◽  
Huitong Shan ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with increasing mortality and poor prognosis. The current understanding of the role of long noncoding RNAs (lncRNAs) in IPF remains limited. In the present study, we identified a lncRNA NONMMUT022554, designated pulmonary fibrosis-regulatory lncRNA (PFRL), with unknown functions and found that its levels were increased in fibrotic lung tissues of mice and pulmonary fibroblasts exposed to transforming growth factor (TGF)-β1. Furthermore, we found that enforced expression of PFRL induced fibroblast activation and collagen deposition, which could be mitigated by the overexpression of microRNA (miR)-26a. By contrast, the inhibition of PFRL could markedly alleviate the TGF-β1-induced upregulation of fibrotic markers and attenuate fibroblast proliferation and differentiation by regulating miR-26a. Meanwhile, our study confirmed that PFRL inhibited the expression and activity of miR-26a, which has been identified as an antifibrotic miRNA in our previous study. Interestingly, our molecular study further confirmed that Smad2 transcriptionally inhibits the expression of miR-26a and that the miR-26a/Smad2 feedback loop mediates the profibrotic effects of PFRL in lung fibrosis. More importantly, knockdown of PFRL ablated bleomycin-induced pulmonary fibrosis in vivo. Taken together, our findings indicate that lncRNA PFRL contributes to the progression of lung fibrosis by modulating the reciprocal repression between miR-26a and Smad2 and that this lncRNA may be a therapeutic target for IPF.


2021 ◽  
Vol 12 ◽  
Author(s):  
Andrea Doni ◽  
Alberto Mantovani ◽  
Barbara Bottazzi ◽  
Remo Castro Russo

PTX3 is a soluble pattern recognition molecule (PRM) belonging to the humoral innate immune system, rapidly produced at inflammatory sites by phagocytes and stromal cells in response to infection or tissue injury. PTX3 interacts with microbial moieties and selected pathogens, with molecules of the complement and hemostatic systems, and with extracellular matrix (ECM) components. In wound sites, PTX3 interacts with fibrin and plasminogen and favors a timely removal of fibrin-rich ECM for an efficient tissue repair. Idiopathic Pulmonary Fibrosis (IPF) is a chronic and progressive interstitial lung disease of unknown origin, associated with excessive ECM deposition affecting tissue architecture, with irreversible loss of lung function and impact on the patient’s life quality. Maccarinelli et al. recently demonstrated a protective role of PTX3 using the bleomycin (BLM)-induced experimental model of lung fibrosis, in line with the reported role of PTX3 in tissue repair. However, the mechanisms and therapeutic potential of PTX3 in IPF remained to be investigated. Herein, we provide new insights on the possible role of PTX3 in the development of IPF and BLM-induced lung fibrosis. In mice, PTX3-deficiency was associated with worsening of the disease and with impaired fibrin removal and subsequently increased collagen deposition. In IPF patients, microarray data indicated a down-regulation of PTX3 expression, thus suggesting a potential rational underlying the development of disease. Therefore, we provide new insights for considering PTX3 as a possible target molecule underlying therapeutic intervention in IPF.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yuan Cheng ◽  
Fei Mo ◽  
Qingfang Li ◽  
Xuejiao Han ◽  
Houhui Shi ◽  
...  

Abstract Background Drug-resistance and severe side effects of chemotherapeutic agents result in unsatisfied survival of patients with lung cancer. CXCLs/CXCR2 axis plays an important role in progression of cancer including lung cancer. However, the specific anti-cancer mechanism of targeting CXCR2 remains unclear. Methods Immunohistochemical analysis of CXCR2 was performed on the microarray of tumor tissues of clinical lung adenocarcinoma and lung squamous cell carcinoma patients. CCK8 test, TUNEL immunofluorescence staining, PI-Annexin V staining, β-galactosidase staining, and Western blot were used to verify the role of CXCR2 in vitro. Animal models of tail vein and subcutaneous injection were applied to investigate the therapeutic role of targeting CXCR2. Flow cytometry, qRT-PCR, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry analysis were performed for further mechanistic investigation. Results The expression of CXCR2 was elevated in both human lung cancer stroma and tumor cells, which was associated with patients’ prognosis. Inhibition of CXCR2 promoted apoptosis, senescence, epithelial-to-mesenchymal transition (EMT), and anti-proliferation of lung cancer cells. In vivo study showed that tumor-associated neutrophils (TANs) were significantly infiltrate into tumor tissues of mouse model, with up-regulated CXCLs/CXCR2 signaling and suppressive molecules, including Arg-1 and TGF-β. SB225002, a selective inhibitor of CXCR2 showed promising therapeutic effect, and significantly reduced infiltration of neutrophils and enhanced anti-tumor T cell activity via promoting CD8+ T cell activation. Meanwhile, blockade of CXCR2 could enhance therapeutic effect of cisplatin via regulation of neutrophils infiltration. Conclusions Our finds verify the therapeutic effects of targeting CXCR2 in lung cancer and uncover the potential mechanism for the increased sensitivity to chemotherapeutic agents by antagonists of CXCR2.


2005 ◽  
Vol 201 (6) ◽  
pp. 925-935 ◽  
Author(s):  
Amir Abdollahi ◽  
Minglun Li ◽  
Gong Ping ◽  
Christian Plathow ◽  
Sophie Domhan ◽  
...  

Pulmonary fibrosis is the consequence of a variety of diseases with no satisfying treatment option. Therapy-induced fibrosis also limits the efficacy of chemotherapy and radiotherapy in numerous cancers. Here, we studied the potential of platelet-derived growth factor (PDGF) receptor tyrosine kinase inhibitors (RTKIs) to attenuate radiation-induced pulmonary fibrosis. Thoraces of C57BL/6 mice were irradiated (20 Gy), and mice were treated with three distinct PDGF RTKIs (SU9518, SU11657, or Imatinib). Irradiation was found to induce severe lung fibrosis resulting in dramatically reduced mouse survival. Treatment with PDGF RTKIs markedly attenuated the development of pulmonary fibrosis in excellent correlation with clinical, histological, and computed tomography results. Importantly, RTKIs also prolonged the life span of irradiated mice. We found that radiation up-regulated expression of PDGF (A–D) isoforms leading to phosphorylation of PDGF receptor, which was strongly inhibited by RTKIs. Our findings suggest a pivotal role of PDGF signaling in the pathogenesis of pulmonary fibrosis and indicate that inhibition of fibrogenesis, rather than inflammation, is critical to antifibrotic treatment. This study points the way to a potential new approach for treating idiopathic or therapy-related forms of lung fibrosis.


2017 ◽  
Vol 312 (1) ◽  
pp. L68-L78 ◽  
Author(s):  
Samik Bindu ◽  
Vinodkumar B. Pillai ◽  
Abhinav Kanwal ◽  
Sadhana Samant ◽  
Gökhan M. Mutlu ◽  
...  

Myofibroblast differentiation is a key process in the pathogenesis of fibrotic diseases. Transforming growth factor-β1 (TGF-β1) is a powerful inducer of myofibroblast differentiation and is implicated in pathogenesis of tissue fibrosis. This study was undertaken to determine the role of mitochondrial deacetylase SIRT3 in TGF-β1-induced myofibroblast differentiation in vitro and lung fibrosis in vivo. Treatment of human lung fibroblasts with TGF-β1 resulted in increased expression of fibrosis markers, smooth muscle α-actin (α-SMA), collagen-1, and fibronectin. TGF-β1 treatment also caused depletion of endogenous SIRT3, which paralleled with increased production of reactive oxygen species (ROS), DNA damage, and subsequent reduction in levels of 8-oxoguanine DNA glycosylase (OGG1), an enzyme that hydrolyzes oxidized guanine (8-oxo-dG) and thus protects DNA from oxidative damage. Overexpression of SIRT3 by adenovirus-mediated transduction reversed the effects of TGF-β1 on ROS production and mitochondrial DNA damage and inhibited TGF-β1-induced myofibroblast differentiation. To determine the antifibrotic role of SIRT3 in vivo, we used the bleomycin-induced mouse model of pulmonary fibrosis. Compared with wild-type controls, Sirt3-knockout mice showed exacerbated fibrosis after intratracheal instillation of bleomycin. Increased lung fibrosis was associated with decreased levels of OGG1 and concomitant accumulation of 8-oxo-dG and increased mitochondrial DNA damage. In contrast, the transgenic mice with whole body Sirt3 overexpression were protected from bleomycin-induced mtDNA damage and development of lung fibrosis. These data demonstrate a critical role of SIRT3 in the control of myofibroblast differentiation and lung fibrosis.


Author(s):  
Yuanyuan Liu ◽  
Wenshan Zhong ◽  
Jinming Zhang ◽  
Weimou Chen ◽  
Ye Lu ◽  
...  

Background and Purpose Idiopathic pulmonary fibrosis is a progressive fatal disease characterized by interstitial remodeling, with high lethality and a lack of effective medical therapies. Tetrandrine has been proposed to present anti-fibrotic effects, but the efficacy and mechanisms of tetrandrine against lung fibrosis has not been systematically evaluated. We sought to study the potential therapeutic effects and mechanisms of tetrandrine in lung fibrosis. Experimental Approach The anti-fibrotic effects of tetrandrine were evaluated in bleomycin-induced mouse models and TGF-β1-stimulated murine lung fibroblasts. We performed Chromatin Immunoprecipitation (ChIP), Immunoprecipitation (IP) and mRFP-GFP-MAP1LC3B adenovirus construct to investigate the novel mechanisms of tetrandrine-induced autophagy. Key Results Tetrandrine decreased TGF-β1-induced expression of α-smooth muscle actin, fibronectin, vimentin and type 1 collagen and proliferation in fibroblasts. Tetrandrine restored TGF-β1-induced impaired autophagy, accompanied by the up-regulation and enhanced interaction of SQSTM1 and MAP1LC3-Ⅱ. ChIP studies revealed that NRF2 bound to SQSTM1 promoter in tetrandrine-induced autophagy. Furthermore, TGF-β1-induced phosphorylated mTOR was inhibited by tetrandrine, with reduced activation levels of Rheb. In vivo tetrandrine suppressed the bleomycin-induced expression of fibrotic markers and improved pulmonary function. Conclusion and Implications Our data suggest that tetrandrine might be recognized as a novel autophagy inducer, thus attenuating lung fibrosis. Tetrandrine should be investigated as a novel therapeutic strategy for IPF.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaofan Lai ◽  
Shaojie Huang ◽  
Sijia Lin ◽  
Lvya Pu ◽  
Yaqing Wang ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive deadly fibrotic lung disease with high prevalence and mortality worldwide. The therapeutic potential of mesenchymal stem cells (MSCs) in pulmonary fibrosis may be attributed to the strong paracrine, anti-inflammatory, anti-apoptosis and immunoregulatory effects. However, the mechanisms underlying the therapeutic effects of MSCs in IPF, especially in terms of alveolar type 2 (AT2) cells senescence, are not well understood. The purpose of this study was to evaluate the role of MSCs in NAD metabolism and senescence of AT2 cells in vitro and in vivo. Methods MSCs were isolated from human bone marrow. The protective effects of MSCs injection in pulmonary fibrosis were assessed via bleomycin mouse models. The senescence of AT2 cells co-cultured with MSCs was evaluated by SA-β-galactosidase assay, immunofluorescence staining and Western blotting. NAD+ level and NAMPT expression in AT2 cells affected by MSCs were determined in vitro and in vivo. FK866 and NAMPT shRNA vectors were used to determine the role of NAMPT in MSCs inhibiting AT2 cells senescence. Results We proved that MSCs attenuate bleomycin-induced pulmonary fibrosis in mice. Senescence of AT2 cells was alleviated in MSCs-treated pulmonary fibrosis mice and when co-cultured with MSCs in vitro. Mechanistic studies showed that NAD+ and NAMPT levels were rescued in AT2 cells co-cultured with MSCs and MSCs could suppress AT2 cells senescence mainly via suppressing lysosome-mediated NAMPT degradation. Conclusions MSCs attenuate AT2 cells senescence by upregulating NAMPT expression and NAD+ levels, thus exerting protective effects in pulmonary fibrosis.


2021 ◽  
Author(s):  
Demin Cheng ◽  
Qi Xu ◽  
Yue Wang ◽  
Guanru Li ◽  
Wenqing Sun ◽  
...  

Abstract Background: Silicosis is one of the most common occupational pulmonary fibrosis caused by respirable silica-based particle exposure, with no ideal drugs at present. Metformin, a commonly used biguanide antidiabetic agent, could activate AMP-activated protein kinase (AMPK) to exert its pharmacological action. Therefore, we sought to investigate the role of metformin in silica-induced lung fibrosis.Methods: The anti-fibrotic role of metformin was assessed in 50 mg/kg silica-induced lung fibrosis model. SiO2-stimulated lung epithelial cells/macrophages and TGF-β-induced differentiated lung fibroblasts were used for in vitro models.Results: At the concentration of 300 mg/kg in the mouse model, metformin significantly reduced lung inflammation and fibrosis in SiO2-instilled mice at the early and late fibrotic stages. Besides, metformin (range 2mM to 10mM) reversed SiO2-induced cell toxicity, oxidative stress, and epithelial-mesenchymal transition process in epithelial cells (A549 and HBE), inhibited inflammation response in macrophages (THP-1), and alleviated TGF-β1-stimulated fibroblast activation in lung fibroblasts (MRC-5) via an AMPK-dependent pathway.Conclusions: In this study, we identified that metformin might be a potential drug for silicosis treatment.


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