scholarly journals Delayed resolution of bleomycin-induced pulmonary fibrosis in absence of MMP13 (collagenase 3)

2019 ◽  
Vol 316 (5) ◽  
pp. L961-L976 ◽  
Author(s):  
Sandra Cabrera ◽  
Mariana Maciel ◽  
Daniel Hernández-Barrientos ◽  
Jazmín Calyeca ◽  
Miguel Gaxiola ◽  
...  

Matrix metalloprotease 13 (MMP13) deficiency in pulmonary fibrosis has described contradictory phenotypes on inflammatory and fibrotic responses after lung injury, and its role during lung fibrosis resolution is still undefined. MMP13 has been considered the main collagenase in rodents, and the remodeling of fibrillar collagen is widely attributed to the action of this enzyme. In this study we aimed to explore the role of MMP13 during lung fibrosis progression and resolution. Lung fibrosis was induced by intratracheal instillation, and inflammatory, fibrotic, and resolution stages were evaluated in Mmp13-null and wild-type (WT) mice. Bronchoalveolar lavage fluid was taken for cytokine array analysis and activity of gelatinases. Our results showed that MMP13 is upregulated mainly during two stages after lung injury, inflammation and resolution of fibrosis, and it is mainly expressed by alveolar and interstitial macrophages. Mmp13-null mice exhibited more extensive inflammation at 7 days after bleomycin treatment, and it was characterized by increased macrophage infiltration and significant alterations in proinflammatory cytokines. We also documented that Mmp13-deficient mice experienced more severe and prolonged lung fibrosis compared with WT mice. Delayed resolution in Mmp13-deficient lungs was characterized by a decreased overall collagenolytic activity and persistent fibrotic foci associated with emphysema-like areas. Together, our findings indicate that MMP13 plays an antifibrotic role and its activity is crucial in lung repair and restoration of tissue integrity during fibrosis resolution.

2018 ◽  
Vol 2 (18) ◽  
pp. 2389-2399
Author(s):  
Deborah François ◽  
Véronique Arocas ◽  
Laurence Venisse ◽  
Karen Aymonnier ◽  
Leila Idir ◽  
...  

Abstract Coagulation and fibrinolytic system deregulation has been implicated in the development of idiopathic pulmonary fibrosis, a devastating form of interstitial lung disease. We used intratracheal instillation of bleomycin to induce pulmonary fibrosis in mice and analyzed the role of serine protease inhibitor E2 (serpinE2)/protease nexin-1 (PN-1), a tissue serpin that exhibits anticoagulant and antifibrinolytic properties. PN-1 deficiency was associated, after bleomycin challenge, with a significant increase in mortality, as well as a marked increase in active thrombin in bronchoalveolar lavage fluids, an overexpression of extracellular matrix proteins, and an accumulation of inflammatory cells in the lungs. Bone marrow transplantation experiments showed that protective PN-1 was derived from hematopoietic cell compartment. A pharmacological strategy using the direct thrombin inhibitor argatroban reversed the deleterious effects of PN-1 deficiency. Concomitant deficiency of the thrombin receptor protease-activated receptor 4 (PAR4) abolished the deleterious effects of PN-1 deficiency in hematopoietic cells. These data demonstrate that prevention of thrombin signaling by PN-1 constitutes an important endogenous mechanism of protection against lung fibrosis and associated mortality. Our findings suggest that appropriate doses of thrombin inhibitors or PAR4 antagonists may provide benefit against progressive lung fibrosis with evidence of deregulated thrombin activity.


2019 ◽  
Vol 400 (12) ◽  
pp. 1617-1627
Author(s):  
Meizi Chen ◽  
Bing Wan ◽  
Suhua Zhu ◽  
Fang Zhang ◽  
Jiajia Jin ◽  
...  

Abstract Geranylgeranyl diphosphate synthase (GGPPS) is an enzyme that catalyzes the synthesis of geranylgeranyl pyrophosphate (GGPP). GGPPS is implicated in many disorders, but its role in idiopathic pulmonary fibrosis (IPF) remains unclear. This study aimed to investigate the role of GGPPS in IPF. We established bleomycin-induced lung injury in a lung-specific GGPPS-deficient mouse (GGPPS−/−) and detected GGPPS expression in lung tissues by Western blot and immunohistochemistry analysis. We found that GGPPS expression increased during lung injury and fibrosis in mice induced by bleomycin, and GGPPS deficiency augmented lung fibrosis. GGPPS deficiency activated lung fibroblast by facilitating transforming growth factor β1 while antagonizing bone morphogenetic protein 4 signaling. Notably, the supplementation of exogenous GGPP mitigated lung fibrosis in GGPPS−/− mice induced by bleomycin. In conclusion, our findings suggest that GGPPS provides protection against pulmonary fibrosis and that the restoration of protein geranylgeranylation may benefit statin-induced lung injury.


2003 ◽  
Vol 285 (6) ◽  
pp. L1255-L1262 ◽  
Author(s):  
Michael J. Segel ◽  
Gabriel Izbicki ◽  
Pazit Y. Cohen ◽  
Reuven Or ◽  
Thomas G. Christensen ◽  
...  

IFN-γ production is upregulated in lung cells (LC) of bleomycin-treated C57BL/6 mice. The present study characterizes the time course, cellular source, and regulation of IFN-γ expression in bleomycin-induced lung injury. IFN-γ mRNA in LC from bleomycin-treated mice peaked 3 days after intratracheal instillation. IFN-γ protein levels were increased at 6 days, as was the percentage of LC expressing IFN-γ. CD4+, CD8+, and natural killer cells each contributed significantly to IFN-γ production. IL-12 mRNA levels were increased at 1 day in LC of bleomycin-treated mice. Anti-IL-12 and anti-IL-18 antibodies decreased IFN-γ production by these cells. To define the role of endogenous IFN-γ in the evolution of bleomycin lung injury, we compared the effect of bleomycin in mice with a targeted knockout mutation of the IFN-γ gene (IFN-γ knockout) and wild-type mice. At 14 days after intratracheal bleomycin, total bronchoalveolar lavage cell counts and lung hydroxyproline were decreased in IFN-γ knockouts compared with wild-type animals. There was no difference in morphometric parameters of fibrosis. Our data show that enhanced IFN-γ production in the lungs of bleomycin-treated mice is at least partly IL-12 and IL-18 dependent. Absence of IFN-γ in IFN-γ knockout mice does not increase pulmonary fibrosis. Endogenous IFN-γ may play a proinflammatory or profibrotic role in bleomycin-induced lung fibrosis.


2021 ◽  
Author(s):  
Ozioma Chioma ◽  
Laura Hesse ◽  
Elizabeth Mallott ◽  
Austin Chapman ◽  
Joseph Van Amburg ◽  
...  

Abstract Independent reports note the significance of gut microbiota on lung disease severity; however, studies using murine models to define the role of the gut microbiome in pulmonary fibrosis progression are missing. We used the bleomycin murine model to quantify lung fibrosis in C57BL/6J mice housed in germ-free, animal biosafety level 1 (ABSL-1), or animal biosafety level 2 (ABSL-2) environments. Mice housed in gnotobiotic facilities are protected from bleomycin-induced pulmonary fibrosis, while ABSL-1 and ABSL-2 mice develop mild fibrosis and severe lung fibrosis, respectively. Metagenomic analysis of the gut microbiota revealed greater microbial diversity in ABSL-1 compared to ABSL-2 mice, with an increased presence of Lactobacilli and Bifidobacterium in ABSL-1 mice. Flow cytometric analysis of single-cell lung suspensions revealed enhanced IL-6/STAT3 /IL-17A signaling in CD4+ T cells of ABSL-2 mice, compared to ABSL-1 or germ-free mice. Fecal microbiota transplantation (FMT) of low microbial diverse stool (ABSL-2) into germ-free mice before bleomycin administration recapitulated the severe fibrosis phenotype, whereas FMT of ABSL-1 stool induced minimal fibrosis. These findings strongly support a causal role of the gut microbiota in augmenting pulmonary fibrosis severity after acute lung injury.


2010 ◽  
Vol 298 (3) ◽  
pp. L382-L391 ◽  
Author(s):  
Jean A. Nemzek ◽  
Omorodola Abatan ◽  
Christopher Fry ◽  
Aladdein Mattar

The effects of individual ELR+ CXC chemokines have been documented in experimental models of acid aspiration. However, aspiration lung injury would be influenced by the combined effects of these chemokines and other factors related to their function. Therefore, the role of the chemokine receptor CXCR2 was examined in lung injury induced by aspiration of acid and acid with gastric particulates. Anesthetized mice were given intratracheal injections of saline, acid solution, or acid containing gastric particles. Within 6 h, bronchoalveolar lavage fluid neutrophils and albumin increased relative to the severity of the insult. Immunohistochemistry and RT-PCR demonstrated striking increases in pulmonary expression of CXCR2 after aspiration. In CXCR2-deficient mice, neutrophil recruitment to airways was significantly reduced after aspiration of either acid or acid with particles. However, lung injury scores were unaffected in Ccr2−/− mice in the acid + particles group. Esterase-stained lung tissue demonstrated that focal aggregates of inflammatory cells contained neutrophils in the Ccr2−/− mice. These studies suggest CXCR2 and its ligands are dominant mediators of neutrophil recruitment to airways after aspiration. However, CXCR2-independent mechanisms recruit neutrophils into areas of cellular aggregation after aspiration of acidified gastric particulates.


2017 ◽  
Vol 313 (1) ◽  
pp. L104-L114 ◽  
Author(s):  
Ziyan Zhu ◽  
Lei Sun ◽  
Rui Hao ◽  
Hongchao Jiang ◽  
Feng Qian ◽  
...  

Lung infections are major causes of acute lung injury (ALI), with limited effective treatment available. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an essential adaptor regulating Toll-like receptors (TLRs). We recently identified Cullin-5 (Cul-5) as a prominent component in the regulation of TRAF6 polyubiquitination, but its physiological significance in ALI has not been explored. In this study, we investigated the potential role of Cul-5 in regulating ALI using mice receiving intratracheal instillation of LPS. We observed that Cul-5-deficient mice displayed reduced lung injury compared with wild-type mice as evidenced by histological analysis, alveolar neutrophil infiltration, and lung liquid accumulation. In addition, inflammatory cytokine expression in bronchoalveolar lavage fluid and lung tissue was also markedly reduced in LPS-treated Cul-5-deficient mice. Interestingly, intratracheal adoptive transfer of Cul-5+/− but not Cul-5+/+ macrophages attenuated neutrophil recruitment, alveolar inflammation, and loss of barrier function in LPS-challenged wild-type mice. Finally, we demonstrated that Cul-5 neddylation following LPS exposure induced Cul-5 and TRAF6 interaction and, thereby, TFAR6 polyubiquitination, leading to NF-κB activation and generation of proinflammatory cytokines. Our data show that neural precursor cell expressed developmentally downregulated protein 8 (Nedd8) modification of Cul-5 is required for its interaction with TRAF6 and activation of the TLR4-TRAF6 signaling pathway in LPS-induced ALI, a feature that may be explored for therapeutic intervention.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jingyao Zhang ◽  
Ruixia Cui ◽  
Yang Feng ◽  
Weiman Gao ◽  
Jianbin Bi ◽  
...  

Background. Pulmonary fibrosis is a chronic progressive fibrosis interstitial lung disease that is characterized by inflammatory infiltration and fibrotic changes. 5-Hydroxytryptamine (5-HT) is an important regulatory factor in inflammation, immunomodulation, and fibrosis. The aim of this study was to investigate the role of 5-HT in bleomycin- (BLM-) induced pulmonary fibrosis through wild-type C57BL/6 (WT) and TPH1 knockout (KO) mouse experiments. Methods. The mice were grouped as follows: WT control group, KO control group, WT BLM group, and KO BLM group. Mice were administrated bleomycin hydrochloride through intratracheal instillation to induce pulmonary fibrosis. Mice were sacrificed 0, 7, 14, and 21 days after modeling, and bronchoalveolar lavage fluid (BALF) and lung tissues were collected to determine the severity of fibrotic changes. Results. The results showed that the weight loss of mice in the WT BLM group was more severe than that in the KO BLM group. H&E and Sirius Red staining revealed that 5-HT markedly aggravated histological damage and fibrotic changes in the lung. Significantly lower levels of hydroxyproline, Ashcroft fibrosis score, total BALF protein and cells, BALF tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6, TNF-α and IL-6 mRNA, malondialdehyde (MDA), and myeloperoxidase- (MPO-) positive cells in the lung tissues, and fibrosis-associated proteins were discovered in the mice from the KO BLM group compared with the WT BLM group. Conclusion. 5-HT aggravated pulmonary fibrosis mainly by promoting the inflammation, exudation of proteins and cells, oxidative stress, and upregulation of fibrosis-associated genes in the lung tissues.


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3599
Author(s):  
Pavel Solopov ◽  
Ruben Manuel Luciano Colunga Biancatelli ◽  
Christiana Dimitropoulou ◽  
John D. Catravas

We previously reported that female mice exhibit protection against chemically induced pulmonary fibrosis and suggested a potential role of estrogen. Phytoestrogens act, at least in part, via stimulation of estrogen receptors; furthermore, compared to residents of Western countries, residents of East Asian countries consume higher amounts of phytoestrogens and exhibit lower rates of pulmonary fibrosis. Therefore, we tested the hypothesis that dietary phytoestrogens ameliorate the severity of experimentally induced pulmonary fibrosis. Male mice placed on either regular soybean diet or phytoestrogen-free diet were instilled with 0.1 N HCl to provoke pulmonary fibrosis. Thirty days later, lung mechanics were measured as indices of lung function and bronchoalveolar lavage fluid (BALF) and lung tissue were analyzed for biomarkers of fibrosis. Mice on phytoestrogen-free diet demonstrated increased mortality and stronger signs of chronic lung injury and pulmonary fibrosis, as reflected in the expression of collagen, extracellular matrix deposition, histology, and lung mechanics, compared to mice on regular diet. We conclude that dietary phytoestrogens play an important role in the pathogenesis of pulmonary fibrosis and suggest that phytoestrogens (e.g., genistein) may be useful as part of a therapeutic regimen against hydrochloric acid-induced lung fibrosis and chronic lung dysfunction.


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.


2012 ◽  
Vol 302 (5) ◽  
pp. L447-L454 ◽  
Author(s):  
Louis R. Standiford ◽  
Theodore J. Standiford ◽  
Michael J. Newstead ◽  
Xianying Zeng ◽  
Megan N. Ballinger ◽  
...  

Toll-like receptors (TLRs) are required for protective host defense against bacterial pathogens. However, the role of TLRs in regulating lung injury during Gram-negative bacterial pneumonia has not been thoroughly investigated. In this study, experiments were performed to evaluate the role of TLR4 in pulmonary responses against Klebsiella pneumoniae (Kp). Compared with wild-type (WT) (Balb/c) mice, mice with defective TLR4 signaling (TLR4lps-d mice) had substantially higher lung bacterial colony-forming units after intratracheal challenge with Kp, which was associated with considerably greater lung permeability and lung cell death. Reduced expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA and protein was noted in lungs and bronchoalveolar lavage fluid of TLR4 mutant mice postintratracheal Kp compared with WT mice, and primary alveolar epithelial cells (AEC) harvested from TLR4lps-d mice produced significantly less GM-CSF in vitro in response to heat-killed Kp compared with WT AEC. TLR4lps-d AEC underwent significantly more apoptosis in response to heat-killed Kp in vitro, and treatment with GM-CSF protected these cells from apoptosis in response to Kp. Finally, intratracheal administration of GM-CSF in TLR4lps-d mice significantly decreased albumin leak, lung cell apoptosis, and bacteremia in Kp-infected mice. Based on these observations, we conclude that TLR4 plays a protective role on lung epithelium during Gram-negative bacterial pneumonia, an effect that is partially mediated by GM-CSF.


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