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Fiore VF, Strane PW, Bryksin AV, White ES, Hagood JS, Barker TH. Conformational coupling of integrin and Thy-1 regulates Fyn priming and fibroblast mechanotransduction. J Cell Biol 2016; 211:173-90. [PMID: 26459603 PMCID: PMC4602038 DOI: 10.1083/jcb.201505007] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Lateral associations between inactive αv integrin and Thy-1 glycoprotein control integrin avidity to extracellular matrix ligand, the localization and kinetics of downstream signal activity, and mechanosensitive remodeling of the cytoskeleton. Progressive fibrosis is characterized by excessive deposition of extracellular matrix (ECM), resulting in gross alterations in tissue mechanics. Changes in tissue mechanics can further augment scar deposition through fibroblast mechanotransduction. In idiopathic pulmonary fibrosis, a fatal form of progressive lung fibrosis, previous work has shown that loss of Thy-1 (CD90) expression in fibroblasts correlates with regions of active fibrogenesis, thus representing a pathologically relevant fibroblast subpopulation. We now show that Thy-1 is a regulator of fibroblast rigidity sensing. Thy-1 physically couples to inactive αvβ3 integrins via its RGD-like motif, altering baseline integrin avidity to ECM ligands and also facilitating preadhesion clustering of integrin and membrane rafts via Thy-1’s glycophosphatidylinositol tether. Disruption of Thy-1–αvβ3 coupling altered recruitment of Src family kinases to adhesion complexes and impaired mechanosensitive, force-induced Rho signaling, and rigidity sensing. Loss of Thy-1 was sufficient to induce myofibroblast differentiation in soft ECMs and may represent a physiological mechanism important in wound healing and fibrosis.
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Affiliation(s)
- Vincent F Fiore
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Patrick W Strane
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Anton V Bryksin
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Eric S White
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109
| | - James S Hagood
- Division of Respiratory Medicine, Department of Pediatrics, University of California, Rady Children's Hospital, San Diego, CA 92105
| | - Thomas H Barker
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
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Abstract
Idiopathic pulmonary fibrosis (IPF) is a severe lung disease, with death occurring within 2-5 years after its onset. IPF affects people in the second half of life. Its causes are unknown. Before 1999, IPF was out from the group of idiopathic interstitial lung diseases as a separate nosological entity. Practitioners very often (80%) make diagnostic errors in IPF and prescribe antibiotics, anti-inflammatory drugs, which worsen the course of this disease. The distinctive feature of the pathogenesis of IPF is the absence of inflammation, which is clinically manifested by the inefficacy of glucocorticosteroids and other anti-inflammatory drugs. Pharmacological agents for the treatment of IPF have been designed since 2000. One of them has been registered and permitted for use in the Russian Federation. This paper is a review of an update on the problem of IPF, which should facilitate the appropriate orientation of physicians in diagnosing and treating this severe disease.
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Affiliation(s)
- E I Shmelev
- Central Research Institute of Tuberculosis, Moscow, Russia
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53
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Guzman-Pruneda FA, Orr Y, Trost JG, Zhang W, Das S, Melicoff E, Maddox J, Nugent M, Mery CM, Adachi I, Schecter MG, Mallory GB, Morales DL, Heinle JS, McKenzie ED. Bronchial artery revascularization and en bloc lung transplant in children. J Heart Lung Transplant 2016; 35:122-129. [DOI: 10.1016/j.healun.2015.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 07/11/2015] [Accepted: 08/22/2015] [Indexed: 10/23/2022] Open
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Abstract
Lung injury and repair is a broad topic that includes many cell types and is relevant to the pathogenesis of most lung diseases. Here, we focus on injury and repair of the alveolus, the principal function of which is to achieve gas exchange. The many cell types and structures present in the alveolus are discussed, with emphasis on their interactions in both health and disease. We define injury as damage resulting in impaired gas exchange; physiologic repair, then, requires restoration of normal alveolar architecture and function. The role of inflammation in both injury and repair of structural alveolar cells, particularly epithelial cells, as well as mechanisms of resolution of inflammation will be addressed. Finally, emphasis is placed on the importance of addressing quantitatively the dynamic and complex multidirectional interactions between the many alveolar cell types and structures in three dimensions over time and in relating such mechanistic studies to physiologic outcomes and human disease.
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55
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Khalil W, Xia H, Bodempudi V, Kahm J, Hergert P, Smith K, Peterson M, Parker M, Herrera J, Bitterman PB, Henke CA. Pathologic Regulation of Collagen I by an Aberrant Protein Phosphatase 2A/Histone Deacetylase C4/MicroRNA-29 Signal Axis in Idiopathic Pulmonary Fibrosis Fibroblasts. Am J Respir Cell Mol Biol 2015; 53:391-9. [PMID: 25612003 DOI: 10.1165/rcmb.2014-0150oc] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by the relentless expansion of fibroblasts depositing type I collagen within the alveolar wall and obliterating the alveolar airspace. MicroRNA (miR)-29 is a potent regulator of collagen expression. In IPF, miR-29 levels are low, whereas type I collagen expression is high. However, the mechanism for suppression of miR-29 and increased type I collagen expression in IPF remains unclear. Here we show that when IPF fibroblasts are seeded on polymerized type I collagen, miR-29c levels are suppressed and type I collagen expression is high. In contrast, miR-29c is high and type I collagen expression is low in control fibroblasts. We demonstrate that the mechanism for suppression of miR-29 during IPF fibroblast interaction with polymerized collagen involves inappropriately low protein phosphatase (PP) 2A function, leading to histone deacetylase (HDA) C4 phosphorylation and decreased nuclear translocation of HDAC4. We demonstrate that overexpression of HDAC4 in IPF fibroblasts restored miR-29c levels and decreased type I collagen expression, whereas knocking down HDAC4 in control fibroblasts suppressed miR-29c levels and increased type I collagen expression. Our data indicate that IPF fibroblast interaction with polymerized type I collagen results in an aberrant PP2A/HDAC4 axis, which suppresses miR-29, causing a pathologic increase in type I collagen expression.
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Affiliation(s)
- Wajahat Khalil
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Hong Xia
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Vidya Bodempudi
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Judy Kahm
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Polla Hergert
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Matthew Parker
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeremy Herrera
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Peter B Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Craig A Henke
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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56
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Madala SK, Thomas G, Edukulla R, Davidson C, Schmidt S, Schehr A, Hardie WD. p70 ribosomal S6 kinase regulates subpleural fibrosis following transforming growth factor-α expression in the lung. Am J Physiol Lung Cell Mol Physiol 2015; 310:L175-86. [PMID: 26566903 DOI: 10.1152/ajplung.00063.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 11/08/2015] [Indexed: 12/28/2022] Open
Abstract
The p70 ribosomal S6 kinase (S6K) is a downstream substrate that is phosphorylated and activated by the mammalian target of rapamycin complex and regulates multiple cellular processes associated with fibrogenesis. Recent studies demonstrate that aberrant mTORC1-S6K signaling contributes to various pathological conditions, but a direct role in pulmonary fibroproliferation has not been established. Increased phosphorylation of the S6K pathway is detected immediately following transforming growth factor-α (TGF-α) expression in a transgenic model of progressive lung fibrosis. To test the hypothesis that the S6K directly regulates pulmonary fibroproliferative disease we determined the cellular sites of S6K phosphorylation during the induction of fibrosis in the TGF-α model and tested the efficacy of specific pharmacological inhibition of the S6K pathway to prevent and reverse fibrotic disease. Following TGF-α expression increased phosphorylation of the S6K was detected in the airway and alveolar epithelium and the mesenchyme of advanced subpleural fibrotic regions. Specific inhibition of the S6K with the small molecule inhibitor LY-2584702 decreased TGF-α and platelet-derived growth factor-β-induced proliferation of lung fibroblasts in vitro. Administration of S6K inhibitors to TGF-α mice prevented the development of extensive subpleural fibrosis and alterations in lung mechanics, and attenuated the increase in total lung hydroxyproline. S6K inhibition after fibrosis was established attenuated the progression of subpleural fibrosis. Together these studies demonstrate targeting the S6K pathway selectively modifies the progression of pulmonary fibrosis in the subpleural compartment of the lung.
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Affiliation(s)
- Satish K Madala
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - George Thomas
- Metabolic Disease Institute, University of Cincinnati School of Medicine, Cincinnati, Ohio; and
| | - Ramakrishna Edukulla
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Cynthia Davidson
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Stephanie Schmidt
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Angelica Schehr
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - William D Hardie
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio;
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Newman DR, Sills WS, Hanrahan K, Ziegler A, Tidd KM, Cook E, Sannes PL. Expression of WNT5A in Idiopathic Pulmonary Fibrosis and Its Control by TGF-β and WNT7B in Human Lung Fibroblasts. J Histochem Cytochem 2015; 64:99-111. [PMID: 26538547 DOI: 10.1369/0022155415617988] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/22/2015] [Indexed: 12/12/2022] Open
Abstract
The wingless (Wnt) family of signaling ligands contributes significantly to lung development and is highly expressed in patients with usual interstitial pneumonia (UIP). We sought to define the cellular distribution of Wnt5A in the lung tissue of patients with idiopathic pulmonary fibrosis (IPF) and the signaling ligands that control its expression in human lung fibroblasts and IPF myofibroblasts. Tissue sections from 40 patients diagnosed with IPF or UIP were probed for the immunolocalization of Wnt5A. Further, isolated lung fibroblasts from normal or IPF human lungs, adenovirally transduced for the overexpression or silencing of Wnt7B or treated with TGF-β1 or its inhibitor, were analyzed for Wnt5A protein expression. Wnt5A was expressed in IPF lungs by airway and alveolar epithelium, smooth muscle cells, endothelium, and myofibroblasts of fibroblastic foci and throughout the interstitium. Forced overexpression of Wnt7B with or without TGF-β1 treatment significantly increased Wnt5A protein expression in normal human smooth muscle cells and fibroblasts but not in IPF myofibroblasts where Wnt5A was already highly expressed. The results demonstrate a wide distribution of Wnt5A expression in cells of the IPF lung and reveal that it is significantly increased by Wnt7B and TGF-β1, which, in combination, could represent key signaling pathways that modulate the pathogenesis of IPF.
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Affiliation(s)
- Donna R Newman
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - W Shane Sills
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - Katherine Hanrahan
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - Amanda Ziegler
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - Kathleen McGinnis Tidd
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - Elizabeth Cook
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
| | - Philip L Sannes
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, and Center for Human Health and the Environment, College of Sciences, North Carolina State University, Raleigh, North Carolina (DRN, WSS, KH, AZ, KMT, EC, PLS)
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58
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Walsh SLF, Wells AU, Sverzellati N, Devaraj A, von der Thüsen J, Yousem SA, Colby TV, Nicholson AG, Hansell DM. Relationship between fibroblastic foci profusion and high resolution CT morphology in fibrotic lung disease. BMC Med 2015; 13:241. [PMID: 26399508 PMCID: PMC4581474 DOI: 10.1186/s12916-015-0479-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 09/03/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Fibroblastic foci profusion on histopathology and severity of traction bronchiectasis on highresolution computed tomography (HRCT) have been shown to be predictors of mortality in patients with idiopathic pulmonary fibrosis (IPF). The aim of this study was to investigate the relationship between fibroblastic foci (FF) profusion and HRCT patterns in patients with a histopathologic diagnosis of usual interstitial pneumonia (UIP), fibrotic non-specific interstitial pneumonia (NSIP) and chronic hypersensitivity pneumonitis (CHP). METHODS The HRCT scans of 162 patients with a histopathologic diagnosis of UIP or fibrotic NSIP (n = 162) were scored on extent of groundglass opacification, reticulation, honeycombing, emphysema and severity of traction bronchiectasis. For each patient, a fibroblastic foci profusion score based on histopathologic appearances was assigned. Relationships between extent of fibroblastic foci and individual HRCT patterns were investigated using univariate correlation analysis and multivariate linear regression. RESULTS Increasing extent of reticulation (P < 0.0001) and increasing severity of traction bronchiectasis (P < 0.0001) were independently associated with increasing FF score within the entire cohort. Within individual multidisciplinary team diagnosis subgroups, the only significant independent association with FF score was severity of traction bronchiectasis in patients with idiopathic pulmonary fibrosis (IPF)/UIP (n = 66, r(2) = 0.19, P < 0.0001) and patients with chronic hypersensitivity pneumonitis (CHP) (n = 49, r(2) = 0.45, P < 0.0001). Furthermore, FF score had the strongest association with severity of traction bronchiectasis in patients with IPF (r(2) = 0.34, P < 0.0001) and CHP (r(2) = 0.35, P < 0.0001). There was no correlation between FF score and severity of traction bronchiectasis in patients with fibrotic NSIP. Global disease extent had the strongest association with severity of traction bronchiectasis in patients with fibrotic NSIP (r(2) = 0.58, P < 0.0001). CONCLUSION In patients with fibrotic lung disease, profusion of fibroblastic foci is strikingly related to the severity of traction bronchiectasis, particularly in IPF and CHP. This may explain the growing evidence that traction bronchiectasis is a predictor of mortality in several fibrotic lung diseases.
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Affiliation(s)
- Simon L F Walsh
- Department of Radiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK. .,Department of Radiology, Kings College Hospital Foundation Trust, Denmark Hill, London, SE5 9RS, UK.
| | - Athol U Wells
- Interstitial Lung Diseases Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - Nicola Sverzellati
- Department of Clinical Sciences, Section of Radiology, University of Parma, Via Gramsci 14, 43126, Parma, Italy
| | - Anand Devaraj
- Department of Radiology, St Georges Hospital, Tooting, London, SW17 0QT, UK
| | | | - Samuel A Yousem
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Thomas V Colby
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Scottsdale, Arizona, USA
| | - Andrew G Nicholson
- Department of Histopathology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - David M Hansell
- Department of Radiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
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59
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Sontake V, Shanmukhappa SK, DiPasquale BA, Reddy GB, Medvedovic M, Hardie WD, White ES, Madala SK. Fibrocytes Regulate Wilms Tumor 1-Positive Cell Accumulation in Severe Fibrotic Lung Disease. THE JOURNAL OF IMMUNOLOGY 2015; 195:3978-91. [PMID: 26371248 DOI: 10.4049/jimmunol.1500963] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 08/04/2015] [Indexed: 02/06/2023]
Abstract
Collagen-producing myofibroblast transdifferentiation is considered a crucial determinant in the formation of scar tissue in the lungs of patients with idiopathic pulmonary fibrosis. Multiple resident pulmonary cell types and bone marrow-derived fibrocytes have been implicated as contributors to fibrotic lesions because of the transdifferentiation potential of these cells into myofibroblasts. In this study, we assessed the expression of Wilms tumor 1 (WT1), a known marker of mesothelial cells, in various cell types in normal and fibrotic lungs. We demonstrate that WT1 is expressed by both mesothelial and mesenchymal cells in idiopathic pulmonary fibrosis lungs but has limited or no expression in normal human lungs. We also demonstrate that WT1(+) cells accumulate in fibrotic lung lesions, using two different mouse models of pulmonary fibrosis and WT1 promoter-driven fluorescent reporter mice. Reconstitution of bone marrow cells into a TGF-α transgenic mouse model demonstrated that fibrocytes do not transform into WT1(+) mesenchymal cells, but they do augment accumulation of WT1(+) cells in severe fibrotic lung disease. Importantly, the number of WT1(+) cells in fibrotic lesions was correlated with severity of lung disease as assessed by changes in lung function, histology, and hydroxyproline levels in mice. Finally, inhibition of WT1 expression was sufficient to attenuate collagen and other extracellular matrix gene production by mesenchymal cells from both murine and human fibrotic lungs. Thus, the results of this study demonstrate a novel association between fibrocyte-driven WT1(+) cell accumulation and severe fibrotic lung disease.
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Affiliation(s)
- Vishwaraj Sontake
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229; Department of Biochemistry, National Institute of Nutrition, Hyderabad 500007, India
| | - Shiva K Shanmukhappa
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Betsy A DiPasquale
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Geereddy B Reddy
- Department of Biochemistry, National Institute of Nutrition, Hyderabad 500007, India
| | - Mario Medvedovic
- Laboratory for Statistical Genomics and Systems Biology, University of Cincinnati, Cincinnati, OH 45267; and
| | - William D Hardie
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Eric S White
- Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI 48109
| | - Satish K Madala
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229;
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60
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Cordeiro CR, Alfaro TM, Freitas S, Cemlyn-Jones J. Idiopathic pulmonary fibrosis. Lung Cancer 2015. [DOI: 10.1183/2312508x.10009414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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61
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Validated prediction of pro-invasive growth factors using a transcriptome-wide invasion signature derived from a complex 3D invasion assay. Sci Rep 2015; 5:12673. [PMID: 26243655 PMCID: PMC4525140 DOI: 10.1038/srep12673] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/03/2015] [Indexed: 12/28/2022] Open
Abstract
The invasion of activated fibroblasts represents a key pathomechanism in fibrotic diseases, carcinogenesis and metastasis. Invading fibroblasts contribute to fibrotic extracellular matrix (ECM) formation and the initiation, progression, or resistance of cancer. To construct transcriptome-wide signatures of fibroblast invasion, we used a multiplex phenotypic 3D invasion assay using lung fibroblasts. Microarray-based gene expression profiles of invading and non-invading fibroblasts demonstrated that 1,049 genes were differentially regulated (>1.5-fold). Unbiased pathway analysis (Ingenuity) identified significant enrichment for the functional clusters 'invasion of cells', 'idiopathic pulmonary fibrosis', and 'metastasis'. Matrix metalloprotease 13 (MMP13), transforming growth factor (TGF)-β1, Caveolin (Cav) 1, Phosphatase and Tensin Homolog (Pten), and secreted frizzled-related protein (Sfrp) 1 were among the highest regulated genes, confirmed by qRT-PCR and Western Blotting. We next performed in silico analysis (Ingenuity Pathway Analysis) to predict mediators that induced fibroblast invasion. Of these, TGFβ1, epidermal growth factor (EGF), fibroblast growth factor (FGF) 2, and platelet-derived growth factor (PDGF)-BB were tested in our 3D invasion assay and found to significantly induce invasion, thus validating the transcriptome profile. Accordingly, our transcriptomic invasion signature describes the invading fibroblast phenotype in unprecedented detail and provides a tool for future functional studies of cell invasion and therapeutic modulation thereof using complex phenotypic assays.
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62
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Batra H, Antony VB. Pleural mesothelial cells in pleural and lung diseases. J Thorac Dis 2015; 7:964-80. [PMID: 26150910 DOI: 10.3978/j.issn.2072-1439.2015.02.19] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 02/11/2015] [Indexed: 12/12/2022]
Abstract
During development, the mesoderm maintains a complex relationship with the developing endoderm giving rise to the mature lung. Pleural mesothelial cells (PMCs) derived from the mesoderm play a key role during the development of the lung. The pleural mesothelium differentiates to give rise to the endothelium and smooth muscle cells via epithelial-to-mesenchymal transition (EMT). An aberrant recapitulation of such developmental pathways can play an important role in the pathogenesis of disease processes such as idiopathic pulmonary fibrosis (IPF). The PMC is the central component of the immune responses of the pleura. When exposed to noxious stimuli, it demonstrates innate immune responses such as Toll-like receptor (TLR) recognition of pathogen associated molecular patterns as well as causes the release of several cytokines to activate adaptive immune responses. Development of pleural effusions occurs due to an imbalance in the dynamic interaction between junctional proteins, n-cadherin and β-catenin, and phosphorylation of adherens junctions between PMCs, which is caused in part by vascular endothelial growth factor (VEGF) released by PMCs. PMCs play an important role in defense mechanisms against bacterial and mycobacterial pleural infections, and in pathogenesis of malignant pleural effusion, asbestos related pleural disease and malignant pleural mesothelioma. PMCs also play a key role in the resolution of inflammation, which can occur with or without fibrosis. Fibrosis occurs as a result of disordered fibrin turnover and due to the effects of cytokines such as transforming growth factor-β, platelet-derived growth factor (PDGF), and basic fibroblast growth factor; which are released by PMCs. Recent studies have demonstrated a role for PMCs in the pathogenesis of IPF suggesting their potential as a cellular biomarker of disease activity and as a possible therapeutic target. Pleural-based therapies targeting PMCs for treatment of IPF and other lung diseases need further exploration.
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Affiliation(s)
- Hitesh Batra
- Division of Pulmonary, Allergy & Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham Birmingham, AL, USA
| | - Veena B Antony
- Division of Pulmonary, Allergy & Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham Birmingham, AL, USA
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63
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Zhang J, Xu P, Wang Y, Wang M, Li H, Lin S, Mao C, Wang B, Song X, Lv C. Astaxanthin prevents pulmonary fibrosis by promoting myofibroblast apoptosis dependent on Drp1-mediated mitochondrial fission. J Cell Mol Med 2015; 19:2215-31. [PMID: 26119034 PMCID: PMC4568926 DOI: 10.1111/jcmm.12609] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/06/2015] [Indexed: 12/22/2022] Open
Abstract
Promotion of myofibroblast apoptosis is a potential therapeutic strategy for pulmonary fibrosis. This study investigated the antifibrotic effect of astaxanthin on the promotion of myofibroblast apoptosis based on dynamin-related protein-1 (Drp1)-mediated mitochondrial fission in vivo and in vitro. Results showed that astaxanthin can inhibit lung parenchymal distortion and collagen deposition, as well as promote myofibroblast apoptosis. Astaxanthin demonstrated pro-apoptotic function in myofibroblasts by contributing to mitochondrial fission, thereby leading to apoptosis by increasing the Drp1 expression and enhancing Drp1 translocation into the mitochondria. Two specific siRNAs were used to demonstrate that Drp1 is necessary to promote astaxanthin-induced mitochondrial fission and apoptosis in myofibroblasts. Drp1-associated genes, such as Bcl-2-associated X protein, cytochrome c, tumour suppressor gene p53 and p53-up-regulated modulator of apoptosis, were highly up-regulated in the astaxanthin group compared with those in the sham group. This study revealed that astaxanthin can prevent pulmonary fibrosis by promoting myofibroblast apoptosis through a Drp1-dependent molecular pathway. Furthermore, astaxanthin provides a potential therapeutic value in pulmonary fibrosis treatment.
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Affiliation(s)
- Jinjin Zhang
- Medicine Research Center, Binzhou Medical University, Yantai, China
| | - Pan Xu
- Department of Respiratory Medicine, Affiliated Hospital to Binzhou Medical University, Binzhou, China
| | - Youlei Wang
- School of Special Education, Binzhou Medical University, Yantai, China
| | - Meirong Wang
- Clinical Laboratory, Affiliated Hospital to Binzhou Medical University, Yantai, China
| | - Hongbo Li
- Department of Respiratory Medicine, Affiliated Hospital to Binzhou Medical University, Binzhou, China
| | - Shengcui Lin
- Department of Respiratory Medicine, Affiliated Hospital to Binzhou Medical University, Yantai, China
| | - Cuiping Mao
- Medicine Research Center, Binzhou Medical University, Yantai, China
| | - Bingsi Wang
- Medicine Research Center, Binzhou Medical University, Yantai, China
| | - Xiaodong Song
- Medicine Research Center, Binzhou Medical University, Yantai, China
| | - Changjun Lv
- Medicine Research Center, Binzhou Medical University, Yantai, China.,Department of Respiratory Medicine, Affiliated Hospital to Binzhou Medical University, Binzhou, China
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64
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Abstract
The challenge facing many fibrotic lung diseases is that these conditions usually present late, often after several decades of repetitive alveolar epithelial injury, during which functional alveolar units are gradually obliterated and replaced with nonfunctional connective tissue. The resulting fibrosis is often progressive and, in the case of idiopathic pulmonary fibrosis (IPF), invariably leads to respiratory insufficiency and, ultimately, the premature death of affected individuals. Recent years have seen a greater appreciation of the relative importance of chronic inflammation as a driver of fibrotic responses. Current evidence suggests that IPF arises as a result of repetitive epithelial injury and a highly aberrant wound healing response in genetically susceptible and aged individuals. Nonspecific anti-inflammatory agents offer no clinical benefit, but the potential contribution of maladaptive immune responses in determining outcome is gaining increasing recognition. The importance of key differences in the tissue-regenerative potential in young versus aged individuals is also beginning to be more fully appreciated. Moreover, there is considerable overlap in the mechanisms underlying tissue repair and cancer, and patients with IPF are at heightened risk of developing lung cancer. Progressive fibrosis and cancer may therefore represent the extremes of a highly dysregulated tissue injury response. This brief review focuses on some of this evidence and on our current understanding of abnormal tissue repair responses after chronic epithelial injury in the specific context of IPF.
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Affiliation(s)
- Rachel C Chambers
- Centre for Inflammation and Tissue Repair, University College London, London, United Kingdom
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65
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Renzoni E, Srihari V, Sestini P. Pathogenesis of idiopathic pulmonary fibrosis: review of recent findings. F1000PRIME REPORTS 2014; 6:69. [PMID: 25165568 PMCID: PMC4126534 DOI: 10.12703/p6-69] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Idiopathic pulmonary fibrosis (IPF) is likely to result from the interaction between environmental exposures, including cigarette smoke, and genetic predisposition. This review focuses on clues provided by recent genetic association studies and other selected data and hypotheses. In IPF, association with surfactant mutations has highlighted the importance of type II epithelial cells, while shortened telomeres in some patients suggest that accelerated aging may play a role in the pathogenesis of lung fibrosis, possibly by affecting the renewal/differentiation potential of epithelial cells. The finding that a common variant in mucin 5B predisposes individuals to both familial and sporadic IPF suggests a hitherto under-investigated role of bronchiolar cells and mucins. Although the pathogenetic link between mucins and lung fibrosis is not known, it is possible that MUC5B overexpression interferes with physiological mucosal host defense, with reduced clearance of micro-organisms or inorganic noxious agents, or induction of endoplasmic reticulum stress. Other components of innate and adaptive immunity are likely to be involved in IPF pathogenesis/progression. Finally, the importance of the clotting cascade in IPF pathogenesis has been confirmed by a recent epidemiological study, in which patients with IPF were almost five times more likely than general population controls to have at least one inherited or acquired clotting defect.
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Affiliation(s)
- Elisabetta Renzoni
- Interstitial Lung Disease Unit, Royal Brompton Hospital and National Heart and Lung InstituteImperial College London, Emmanuel Kaye Building, 1B Manresa Road, London SW3 6LRUK
| | - Veeraraghavan Srihari
- Department of Medicine, Division of Pulmonary, Allergy and Critical Care, Emory University1365 Clifton Rd NE Rm A 4319, Atlanta, GA 30322USA
| | - Piersante Sestini
- Respiratory Medicine Department, Ospedale “Le Scotte”, University of Siena, viale Bracci53100 SienaItaly
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66
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Batra H, Antony VB. The pleural mesothelium in development and disease. Front Physiol 2014; 5:284. [PMID: 25136318 PMCID: PMC4117979 DOI: 10.3389/fphys.2014.00284] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 07/10/2014] [Indexed: 12/20/2022] Open
Abstract
The pleural mesothelium, derived from the embryonic mesoderm, is formed by a metabolically active monolayer of cells that blanket the chest wall and lungs on the parietal and visceral surfaces, respectively. The pleura and lungs are formed as a result of an intricate relationship between the mesoderm and the endoderm during development. Mesenchymal signaling pathways such as Wnt/B-catenin, Bmp4, and sonic hedgehog appear to be quintessential for lung development. Pleural Mesothelial Cells (PMCs) are known to express Wilms tumor-1 (Wt1) gene and in lineage labeling studies of the developing embryo, PMCs were found to track into the lung parenchyma and undergo mesothelial-mesenchymal transition (MMT) to form α-smooth muscle actin (α-SMA)-positive cells of the mesenchyme and vasculature. There is definite evidence that mesothelial cells can differentiate and this seems to play an important role in pleural and parenchymal pathologies. Mesothelial cells can differentiate into adipocytes, chondrocytes, and osteoblasts; and have been shown to clonally generate fibroblasts and smooth muscle cells in murine models. This supports the possibility that they may also modulate lung injury-repair by re-activation of developmental programs in the adult reflecting an altered recapitulation of development, with implications for regenerative biology of the lung. In a mouse model of lung fibrosis using lineage-tracing studies, PMCs lost their polarity and cell-cell junctional complexes, migrated into lung parenchyma, and underwent phenotypic transition into myofibroblasts in response to the pro-fibrotic mediator, transforming growth factor-β1 (TGF-β1). However, intra-pleural heme-oxygenase-1 (HO-1) induction inhibited PMC migration after intra-tracheal fibrogenic injury. Intra-pleural fluorescein isothiocyanate labeled nanoparticles decorated with a surface antibody to mesothelin, a surface marker of mesothelial cells, migrate into the lung parenchyma with PMCs supporting a potential role for pleural based therapies to modulate pleural mesothelial activation and parenchymal disease progression.
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Affiliation(s)
- Hitesh Batra
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham Birmingham, AL, USA
| | - Veena B Antony
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham Birmingham, AL, USA
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Bodempudi V, Hergert P, Smith K, Xia H, Herrera J, Peterson M, Khalil W, Kahm J, Bitterman PB, Henke CA. miR-210 promotes IPF fibroblast proliferation in response to hypoxia. Am J Physiol Lung Cell Mol Physiol 2014; 307:L283-94. [PMID: 24951777 DOI: 10.1152/ajplung.00069.2014] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by the relentless spread of fibroblasts from scarred alveoli into adjacent alveolar units, resulting in progressive hypoxia and death by asphyxiation. Although hypoxia is a prominent clinical feature of IPF, the role of hypoxia as a driver of the progressive fibrotic nature of the disease has not been explored. Here, we demonstrate that hypoxia robustly stimulates the proliferation of IPF fibroblasts. We found that miR-210 expression markedly increases in IPF fibroblasts in response to hypoxia and that knockdown of miR-210 decreases hypoxia-induced IPF fibroblast proliferation. Silencing hypoxia-inducible factor (HIF)-2α inhibits the hypoxia-mediated increase in miR-210 expression and blocks IPF fibroblast proliferation, indicating that HIF-2α is upstream of miR-210. We demonstrate that the miR-210 downstream target MNT is repressed in hypoxic IPF fibroblasts and that knockdown of miR-210 increases MNT expression. Overexpression of MNT inhibits hypoxia-induced IPF fibroblast proliferation. Together, these data indicate that hypoxia potently stimulates miR-210 expression via HIF-2α, and high miR-210 expression drives fibroblast proliferation by repressing the c-myc inhibitor, MNT. In situ analysis of IPF lung tissue demonstrates miR-210 expression in a similar distribution with HIF-2α and the hypoxic marker carbonic anhydrase-IX in cells within the IPF fibrotic reticulum. Our results raise the possibility that a pathological feed-forward loop exists in the IPF lung, in which hypoxia promotes IPF fibroblast proliferation via stimulation of miR-210 expression, which in turn worsens hypoxia.
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Affiliation(s)
- Vidya Bodempudi
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Polla Hergert
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Hong Xia
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeremy Herrera
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Wajahat Khalil
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Judy Kahm
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Peter B Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Craig A Henke
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
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68
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Xia H, Bodempudi V, Benyumov A, Hergert P, Tank D, Herrera J, Braziunas J, Larsson O, Parker M, Rossi D, Smith K, Peterson M, Limper A, Jessurun J, Connett J, Ingbar D, Phan S, Bitterman PB, Henke CA. Identification of a cell-of-origin for fibroblasts comprising the fibrotic reticulum in idiopathic pulmonary fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1369-83. [PMID: 24631025 PMCID: PMC4005984 DOI: 10.1016/j.ajpath.2014.01.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 12/26/2013] [Accepted: 01/02/2014] [Indexed: 01/08/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive disease of the middle aged and elderly with a prevalence of one million persons worldwide. The fibrosis spreads from affected alveoli into contiguous alveoli, creating a reticular network that leads to death by asphyxiation. Lung fibroblasts from patients with IPF have phenotypic hallmarks, distinguishing them from their normal counterparts: pathologically activated Akt signaling axis, increased collagen and α-smooth muscle actin expression, distinct gene expression profile, and ability to form fibrotic lesions in model organisms. Despite the centrality of these fibroblasts in disease pathogenesis, their origin remains uncertain. Here, we report the identification of cells in the lungs of patients with IPF with the properties of mesenchymal progenitors. In contrast to progenitors isolated from nonfibrotic lungs, IPF mesenchymal progenitor cells produce daughter cells manifesting the full spectrum of IPF hallmarks, including the ability to form fibrotic lesions in zebrafish embryos and mouse lungs, and a transcriptional profile reflecting these properties. Morphological analysis of IPF lung tissue revealed that mesenchymal progenitor cells and cells with the characteristics of their progeny comprised the fibrotic reticulum. These data establish that the lungs of patients with IPF contain pathological mesenchymal progenitor cells that are cells of origin for fibrosis-mediating fibroblasts. These fibrogenic mesenchymal progenitors and their progeny represent an unexplored target for novel therapies to interdict fibrosis.
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Affiliation(s)
- Hong Xia
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Vidya Bodempudi
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Alexey Benyumov
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Polla Hergert
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Damien Tank
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeremy Herrera
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeff Braziunas
- Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota
| | - Ola Larsson
- Department of Oncology and Pathology, Karolinska Institute, Stockholm, Sweden
| | - Matthew Parker
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Daniel Rossi
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Andrew Limper
- Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Jose Jessurun
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota
| | - John Connett
- Division of Biostatistics School of Public Health, University of Minnesota, Minneapolis, Minnesota
| | - David Ingbar
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Sem Phan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Peter B Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Craig A Henke
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
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Parker MW, Rossi D, Peterson M, Smith K, Sikström K, White ES, Connett JE, Henke CA, Larsson O, Bitterman PB. Fibrotic extracellular matrix activates a profibrotic positive feedback loop. J Clin Invest 2014; 124:1622-35. [PMID: 24590289 DOI: 10.1172/jci71386] [Citation(s) in RCA: 398] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 12/27/2013] [Indexed: 12/13/2022] Open
Abstract
Pathological remodeling of the extracellular matrix (ECM) by fibroblasts leads to organ failure. Development of idiopathic pulmonary fibrosis (IPF) is characterized by a progressive fibrotic scarring in the lung that ultimately leads to asphyxiation; however, the cascade of events that promote IPF are not well defined. Here, we examined how the interplay between the ECM and fibroblasts affects both the transcriptome and translatome by culturing primary fibroblasts generated from IPF patient lung tissue or nonfibrotic lung tissue on decellularized lung ECM from either IPF or control patients. Surprisingly, the origin of the ECM had a greater impact on gene expression than did cell origin, and differences in translational control were more prominent than alterations in transcriptional regulation. Strikingly, genes that were translationally activated by IPF-derived ECM were enriched for those encoding ECM proteins detected in IPF tissue. We determined that genes encoding IPF-associated ECM proteins are targets for miR-29, which was downregulated in fibroblasts grown on IPF-derived ECM, and baseline expression of ECM targets could be restored by overexpression of miR-29. Our data support a model in which fibroblasts are activated to pathologically remodel the ECM in IPF via a positive feedback loop between fibroblasts and aberrant ECM. Interrupting this loop may be a strategy for IPF treatment.
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Dual targeting of MEK and PI3K pathways attenuates established and progressive pulmonary fibrosis. PLoS One 2014; 9:e86536. [PMID: 24475138 PMCID: PMC3903543 DOI: 10.1371/journal.pone.0086536] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/10/2013] [Indexed: 01/07/2023] Open
Abstract
Pulmonary fibrosis is often triggered by an epithelial injury resulting in the formation of fibrotic lesions in the lung, which progress to impair gas exchange and ultimately cause death. Recent clinical trials using drugs that target either inflammation or a specific molecule have failed, suggesting that multiple pathways and cellular processes need to be attenuated for effective reversal of established and progressive fibrosis. Although activation of MAPK and PI3K pathways have been detected in human fibrotic lung samples, the therapeutic benefits of in vivo modulation of the MAPK and PI3K pathways in combination are unknown. Overexpression of TGFα in the lung epithelium of transgenic mice results in the formation of fibrotic lesions similar to those found in human pulmonary fibrosis, and previous work from our group shows that inhibitors of either the MAPK or PI3K pathway can alter the progression of fibrosis. In this study, we sought to determine whether simultaneous inhibition of the MAPK and PI3K signaling pathways is a more effective therapeutic strategy for established and progressive pulmonary fibrosis. Our results showed that inhibiting both pathways had additive effects compared to inhibiting either pathway alone in reducing fibrotic burden, including reducing lung weight, pleural thickness, and total collagen in the lungs of TGFα mice. This study demonstrates that inhibiting MEK and PI3K in combination abolishes proliferative changes associated with fibrosis and myfibroblast accumulation and thus may serve as a therapeutic option in the treatment of human fibrotic lung disease where these pathways play a role.
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71
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Gardner A, Borthwick LA, Fisher AJ. Lung epithelial wound healing in health and disease. Expert Rev Respir Med 2014; 4:647-60. [DOI: 10.1586/ers.10.62] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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McLoughlin P, Keane MP. Physiological and pathological angiogenesis in the adult pulmonary circulation. Compr Physiol 2013; 1:1473-508. [PMID: 23733650 DOI: 10.1002/cphy.c100034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Angiogenesis occurs during growth and physiological adaptation in many systemic organs, for example, exercise-induced skeletal and cardiac muscle hypertrophy, ovulation, and tissue repair. Disordered angiogenesis contributes to chronic inflammatory disease processes and to tumor growth and metastasis. Although it was previously thought that the adult pulmonary circulation was incapable of supporting new vessel growth, over that past 10 years new data have shown that angiogenesis within this circulation occurs both during physiological adaptive processes and as part of the pathogenic mechanisms of lung diseases. Here we review the expression of vascular growth factors in the adult lung, their essential role in pulmonary vascular homeostasis and the changes in their expression that occur in response to physiological challenges and in disease. We consider the evidence for adaptive neovascularization in the pulmonary circulation in response to alveolar hypoxia and during lung growth following pneumonectomy in the adult lung. In addition, we review the role of disordered angiogenesis in specific lung diseases including idiopathic pulmonary fibrosis, acute adult distress syndrome and both primary and metastatic tumors of the lung. Finally, we examine recent experimental data showing that therapeutic enhancement of pulmonary angiogenesis has the potential to treat lung diseases characterized by vessel loss.
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Affiliation(s)
- Paul McLoughlin
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, and St. Vincent's University Hospital, Dublin, Ireland.
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73
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Karki S, Surolia R, Hock TD, Guroji P, Zolak JS, Duggal R, Ye T, Thannickal VJ, Antony VB. Wilms' tumor 1 (Wt1) regulates pleural mesothelial cell plasticity and transition into myofibroblasts in idiopathic pulmonary fibrosis. FASEB J 2013; 28:1122-31. [PMID: 24265486 DOI: 10.1096/fj.13-236828] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Pleural mesothelial cells (PMCs), which are derived from the mesoderm, exhibit an extraordinary capacity to undergo phenotypic changes during development and disease. PMC transformation and trafficking has a newly defined role in idiopathic pulmonary fibrosis (IPF); however, the contribution of Wilms' tumor 1 (Wt1)-positive PMCs to the generation of pathognomonic myofibroblasts remains unclear. PMCs were obtained from IPF lung explants and healthy donor lungs that were not used for transplantation. Short hairpin Wt1-knockdown PMCs (sh Wt1) were generated with Wt1 shRNA, and morphologic and functional assays were performed in vitro. Loss of Wt1 abrogated the PMC phenotype and showed evidence of mesothelial-to-mesenchymal transition (MMT), with a reduced expression of E-cadherin and an increase in the profibrotic markers α-smooth muscle actin (α-SMA) and fibronectin, along with increased migration and contractility, compared with that of the control. Migration of PMCs in response to active transforming growth factor (TGF)-β1 was assessed by live-cell imaging with 2-photon microscopy and 3D imaging, of Wt1-EGFP transgenic mice. Lineage-tracing experiments to map the fate of Wt1(+) PMCs in mouse lung in response to TGF-β1 were also performed by using a Cre-loxP system. Our results, for the first time, demonstrate that Wt1 is necessary for the morphologic integrity of pleural membrane and that loss of Wt1 contributes to IPF via MMT of PMCs into a myofibroblast phenotype.
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Affiliation(s)
- Suman Karki
- 2Department of Medicine, University of Alabama at Birmingham, AL 35294, USA;
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74
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Wolters PJ, Collard HR, Jones KD. Pathogenesis of idiopathic pulmonary fibrosis. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2013; 9:157-79. [PMID: 24050627 DOI: 10.1146/annurev-pathol-012513-104706] [Citation(s) in RCA: 562] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Idiopathic pulmonary fibrosis (IPF) is a fibrosing interstitial lung disease associated with aging that is characterized by the histopathological pattern of usual interstitial pneumonia. Although an understanding of the pathogenesis of IPF is incomplete, recent advances delineating specific clinical and pathologic features of IPF have led to better definition of the molecular pathways that are pathologically activated in the disease. In this review we highlight several of these advances, with a focus on genetic predisposition to IPF and how genetic changes, which occur primarily in epithelial cells, lead to activation of profibrotic pathways in epithelial cells. We then discuss the pathologic changes within IPF fibroblasts and the extracellular matrix, and we conclude with a summary of how these profibrotic pathways may be interrelated.
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Affiliation(s)
- Paul J Wolters
- Department of Medicine, School of Medicine, University of California, San Francisco, California 94143; ,
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75
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Chilosi M, Carloni A, Rossi A, Poletti V. Premature lung aging and cellular senescence in the pathogenesis of idiopathic pulmonary fibrosis and COPD/emphysema. Transl Res 2013; 162:156-73. [PMID: 23831269 DOI: 10.1016/j.trsl.2013.06.004] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 06/11/2013] [Indexed: 02/06/2023]
Abstract
Different anatomic and physiological changes occur in the lung of aging people that can affect pulmonary functions, and different pulmonary diseases, including deadly diseases such as chronic obstructive pulmonary disease (COPD)/emphysema and idiopathic pulmonary fibrosis (IPF), can be related to an acceleration of the aging process. The individual genetic background, as well as exposure to a variety of toxic substances (cigarette smoke in primis) can contribute significantly to accelerating pulmonary senescence. Premature aging can impair lung function by different ways: by interfering specifically with tissue repair mechanisms after damage, thus perturbing the correct crosstalk between mesenchymal and epithelial components; by inducing systemic and/or local alteration of the immune system, thus impairing the complex mechanisms of lung defense against infections; and by stimulating a local and/or systemic inflammatory condition (inflammaging). According to recently proposed pathogenic models in COPD and IPF, premature cellular senescence likely affects distinct progenitors cells (mesenchymal stem cells in COPD, alveolar epithelial precursors in IPF), leading to stem cell exhaustion. In this review, the large amount of data supporting this pathogenic view are discussed, with emphasis on the possible molecular and cellular mechanisms leading to the severe parenchymal remodeling that characterizes, in different ways, these deadly diseases.
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Affiliation(s)
- Marco Chilosi
- Department of Pathology, University of Verona, Verona, Italy.
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76
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Coffey E, Newman DR, Sannes PL. Expression of fibroblast growth factor 9 in normal human lung and idiopathic pulmonary fibrosis. J Histochem Cytochem 2013; 61:671-9. [PMID: 23797050 DOI: 10.1369/0022155413497366] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The fibroblast growth factor (FGF) family of signaling ligands contributes significantly to lung development and maintenance in the adult. FGF9 is involved in control of epithelial branching and mesenchymal proliferation and expansion in developing lungs. However, its activity and expression in the normal adult lung and by epithelial and interstitial cells in fibroproliferative diseases like idiopathic pulmonary fibrosis (IPF) are unknown. Tissue samples from normal organ donor human lungs and those of a cohort of patients with mild to severe IPF were sectioned and stained for the immunolocalization of FGF9. In normal lungs, FGF9 was confined to smooth muscle surrounding airways, alveolar ducts and sacs, and blood vessels. In addition to these same sites, lungs of IPF patients expressed FGF9 in a population of myofibroblasts within fibroblastic foci, hypertrophic and hyperplastic epithelium of airways and alveoli, and smooth muscle cells surrounding vessels embedded in thickened interstitium. The results demonstrate that FGF9 protein increased in regions of active cellular hyperplasia, metaplasia, and fibrotic expansion of IPF lungs, and in isolated human lung fibroblasts treated with TGF-β1 and/or overexpressing Wnt7B. The cellular distribution and established biologic activity of FGF9 make it a potentially strong candidate for contributing to the progression of IPF.
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Affiliation(s)
- Emily Coffey
- Department of Molecular Biomedical Sciences, Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27607, USA
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Lara AR, Cosgrove GP, Janssen WJ, Huie TJ, Burnham EL, Heinz DE, Curran-Everett D, Sahin H, Schwarz MI, Cool CD, Groshong SD, Geraci MW, Tuder RM, Hyde DM, Henson PM. Increased lymphatic vessel length is associated with the fibroblast reticulum and disease severity in usual interstitial pneumonia and nonspecific interstitial pneumonia. Chest 2013; 142:1569-1576. [PMID: 22797508 DOI: 10.1378/chest.12-0029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Lymphangiogenesis responds to tissue injury as a key component of normal wound healing. The development of fibrosis in the idiopathic interstitial pneumonias may result from abnormal wound healing in response to injury. We hypothesize that increased lymphatic vessel (LV) length, a marker of lymphangiogenesis, is associated with parenchymal components of the fibroblast reticulum (organizing collagen, fibrotic collagen, and fibroblast foci), and its extent correlates with disease severity. METHODS We assessed stereologically the parenchymal structure of fibrotic lungs and its associated lymphatic network, which was highlighted immunohistochemically in age-matched samples of usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP) with FVC < 80%, COPD with a Global Initiative for Obstructive Lung Disease stage 0, and normal control lungs. RESULTS LV length density, as opposed to vessel volume density, was found to be associated with organizing and fibrotic collagen density (P < .0001). Length density of LVs and the volume density of organizing and fibrotic collagen were significantly associated with severity of both % FVC (P < .001) and diffusing capacity of the lung for carbon monoxide (P < .001). CONCLUSIONS Severity of disease in UIP and NSIP is associated with increased LV length and is strongly associated with components of the fibroblast reticulum, namely organizing and fibrotic collagen, which supports a pathogenic role of LVs in these two diseases. Furthermore, the absence of definable differences between UIP and NSIP suggests that LVs are a unifying mechanism for the development of fibrosis in these fibrotic lung diseases.
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Affiliation(s)
- Abigail R Lara
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO.
| | - Gregory P Cosgrove
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO; Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, CO
| | - William J Janssen
- Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, CO
| | - Tristan J Huie
- Division of Pulmonary and Critical Care Medicine, National Jewish Health, Denver, CO
| | - Ellen L Burnham
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO
| | - David E Heinz
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO
| | - Douglas Curran-Everett
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Denver, Aurora, CO; Department of Biostatistics and Bioinformatics, National Jewish Health, Denver, CO
| | - Hakan Sahin
- Department of Radiology, University of Colorado Denver, Aurora, CO
| | - Marvin I Schwarz
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO
| | - Carlyne D Cool
- Department of Pathology, University of Colorado Denver, Aurora, CO
| | | | - Mark W Geraci
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO
| | - Rubin M Tuder
- Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Aurora, CO
| | - Dallas M Hyde
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Peter M Henson
- Division of Immunology, National Jewish Health, Denver, CO
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Maher TM. The diagnosis of idiopathic pulmonary fibrosis and its complications. ACTA ACUST UNITED AC 2013; 2:1317-31. [PMID: 23496780 DOI: 10.1517/17530050802549484] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a devastating, progressive condition with a median survival of 2.8 - 4 years from diagnosis. Clinicians confronted with a patient with fibrosing lung disease need to be reliably able to distinguish IPF from other diffuse parenchymal lung diseases. Furthermore, they need to be able to gauge prognosis, evaluate timing of interventions including referral for transplant, assess reliably the effectiveness of treatment and be able to detect rapidly the development of disease complications. OBJECTIVE/METHOD This paper provides an overview of currently available diagnostic tests for IPF and its complications and evaluates the possible future role of candidate biomarkers in the diagnosis and assessment of patients with IPF. A literature search was performed for papers evaluating diagnostic tests in the diagnosis of IPF and its complications. CONCLUSION Computed tomography combined with clinical data is sufficient for diagnosing IPF in approximately two-thirds of patients with the condition. For the remaining patients, histological assessment is important in achieving a precise diagnosis. Serial measurements of carbon monoxide diffusing capacity and forced vital capacity provide the best prognostic indicator in IPF. Potential biomarkers for diagnosing IPF include KL-6, MMP1 and MMP7. Brain naturetic peptide shows promise as a non-invasive screening tool for the diagnosis of IPF-associated pulmonary hypertension.
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Affiliation(s)
- Toby M Maher
- Centre for Respiratory Research, University College London, Rayne Institute, 5 University Street, WC1E 6JJ, UK +0207 679 6975 ; +0207 679 6973 ;
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81
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Tissue mechanics and fibrosis. Biochim Biophys Acta Mol Basis Dis 2013; 1832:884-90. [PMID: 23434892 DOI: 10.1016/j.bbadis.2013.02.007] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 02/10/2013] [Indexed: 12/17/2022]
Abstract
Mechanical forces are essential to the development and progression of fibrosis, and are likely to be as important as soluble factors. These forces regulate the phenotype and proliferation of myofibroblasts and other cells in damaged tissues, the activation of growth factors, the structure and mechanics of the matrix, and, potentially, tissue patterning. Better understanding of the variety and magnitude of forces, the characteristics of those forces in biological tissues, and their impact on fibrosis in multiple tissues is needed and may lead to identification of important new therapeutic targets. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.
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Zolak JS, Jagirdar R, Surolia R, Karki S, Oliva O, Hock T, Guroji P, Ding Q, Liu RM, Bolisetty S, Agarwal A, Thannickal VJ, Antony VB. Pleural mesothelial cell differentiation and invasion in fibrogenic lung injury. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:1239-47. [PMID: 23399488 DOI: 10.1016/j.ajpath.2012.12.030] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/01/2012] [Accepted: 12/12/2012] [Indexed: 11/25/2022]
Abstract
The origin of the myofibroblast in fibrotic lung disease is uncertain, and no effective medical therapy for fibrosis exists. We have previously demonstrated that transforming growth factor-β1 (TGF-β1) induces pleural mesothelial cell (PMC) transformation into myofibroblasts and haptotactic migration in vitro. Whether PMC differentiation and migration occurs in vivo, and whether this response can be modulated for therapeutic benefit, is unknown. Here, using mice recombinant for green fluorescent protein (GFP) driven by the Wilms tumor-1 (WT-1) promoter, we demonstrate PMC trafficking into the lung and differentiation into myofibroblasts. Carbon monoxide or the induction of heme oxygenase-1 (HO-1) inhibited the expression of myofibroblast markers, contractility, and haptotaxis in PMCs treated with TGF-β1. Intrapleural HO-1 induction inhibited PMC migration after intratracheal fibrogenic injury. PMCs from patients with idiopathic pulmonary fibrosis (IPF) exhibited increased expression of myofibroblast markers and enhanced contractility and haptotaxis, compared with normal PMCs. Carbon monoxide reversed this IPF PMC profibrotic phenotype. WT-1-expressing cells were present within fibrotic regions of the lungs in IPF subjects, supporting a role for PMC differentiation and trafficking as contributors to the myofibroblast population in lung fibrosis. Our findings also support a potential role for pleural-based therapies to modulate pleural mesothelial activation and parenchymal fibrosis progression.
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Affiliation(s)
- Jason S Zolak
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006, USA.
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83
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Friedman SL, Sheppard D, Duffield JS, Violette S. Therapy for Fibrotic Diseases: Nearing the Starting Line. Sci Transl Med 2013; 5:167sr1. [DOI: 10.1126/scitranslmed.3004700] [Citation(s) in RCA: 480] [Impact Index Per Article: 43.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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84
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Complement-mediated microvascular injury leads to chronic rejection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 735:233-46. [PMID: 23402031 DOI: 10.1007/978-1-4614-4118-2_16] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microvascular loss may be an unappreciated root cause of chronic rejection for all solid organ transplants. As the only solid organ transplant that does not undergo primary systemic arterial revascularization at the time of surgery, lung transplants rely on the establishment of a microcirculation and are especially vulnerable to the effects of microvascular loss. Microangiopathy, with its attendant ischemia, can lead to tissue infarction and airway fibrosis. Maintaining healthy vasculature in lung allografts may be critical for preventing terminal airway fibrosis, also known as the bronchiolitis obliterans syndrome (BOS). BOS is the major obstacle to lung transplant success and affects up to 60% of patients surviving 5 years. The role of complement in causing acute microvascular loss and ischemia during rejection has recently been examined using the mouse orthotopic tracheal transplantation; this is an ideal model for parsing the role of airway vasculature in rejection. Prior to the development of airway fibrosis in rejecting tracheal allografts, C3 deposits on the vascular endothelium just as tissue hypoxia is first detected. With the eventual destruction of vessels, microvascular blood flow to the graft stops altogether for several days. Complement deficiency and complement inhibition lead to markedly improved tissue oxygenation in transplants, diminished airway remodeling, and accelerated vascular repair. CD4+ T cells and antibody-dependent complement activity independently mediate vascular destruction and sustained tissue ischemia during acute rejection. Consequently, interceding against complement-mediated microvascular injury with adjunctive therapy during acute rejection episodes, in addition to standard immunosuppression which targets CD4+ T cells, may help prevent the subsequent development of chronic rejection.
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85
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Fontenot AP, Simonian PL. Immunologic lung diseases. Clin Immunol 2013. [DOI: 10.1016/b978-0-7234-3691-1.00085-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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86
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Idiopathic pulmonary fibrosis: an altered fibroblast proliferation linked to cancer biology. Ann Am Thorac Soc 2012; 9:153-7. [PMID: 22802290 DOI: 10.1513/pats.201203-025aw] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The fibrotic process that characterizes idiopathic pulmonary fibrosis (IPF) is commonly considered the result of a recurrent injury to the alveolar epithelium followed by an uncontrolled proliferation of fibroblasts. However, based on considerable scientific evidence, it has been recently hypothesized that IPF might be considered a neoproliferative disorder of the lung because this disease exhibits several pathogenic features similar to cancer. Indeed, epigenetic and genetic abnormalities, altered cell-to-cell communications, uncontrolled proliferation, and abnormal activation of specific signal transduction pathways are biological hallmarks that characterize the pathogenesis of IPF and cancer. IPF remains a disease marked by a survival of 3 years, and little therapeutic progress has been made in the last few years, underlining the urgent need to improve research and to change our approach to the comprehension of this disease. The concept of IPF as a cancer-like disease may be helpful in identifying new pathogenic mechanisms that can be borrowed from cancer biology, potentially leading to different and more effective therapeutic approaches. Such vision will hopefully increase the awareness of this disease among the public and the scientific community.
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87
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Liu XX, Zhou HJ, Cai L, Zhang W, Ma JL, Tao XJ, Yu JN. NADPH oxidase-dependent formation of reactive oxygen species contributes to transforming growth factor β1-induced epithelial-mesenchymal transition in rat peritoneal mesothelial cells, and the role of astragalus intervention. Chin J Integr Med 2012; 20:667-74. [PMID: 23090359 DOI: 10.1007/s11655-012-1176-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To investigate the role of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidasedependent formation of reactive oxygen species (ROS) in the transforming growth factor β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in rat peritoneal mesothelial cells (RPMCs), and the effect of Astragalus injection (AGI) intervention. METHODS Primary RPMCs were cultured to the second generation in vitro. After synchronization for 24 h, the cells were randomly assigned to the following groups: control (Group A), AGI (2 g/mL; Group B), TGF-β1 (10 ng/mL; Group C), TGF-β1 (10 ng/mL) + AGI (2 g/mL; Group D; pretreated for 1 h with AGI before TGF-β1 stimulation). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were employed to evaluate the mRNA and protein expression of the NADPH oxidase subunit p67phox, α-smooth muscle actin (α-SMA) and E-cadherin. The dichlorofluorescein-sensitive cellular ROS levels were measured by a fluorometric assay and confocal microscopy. RESULTS TGF-β1 significantly induced NADPH oxidase subunit p67phox mRNA and protein expression in RPMCs, as well as inducing the production of intracellular ROS. AGI inhibited this TGF-β1-induced up-regulation by 39.3% and 47.8%, respectively (P<0.05), as well as inhibiting the TGF-β1-induced ROS generation by 56.3% (P<0.05). TGF-β1 also induced α-SMA mRNA and protein expression, and down-regulated E-cadherin mRNA and protein expression (P<0.05). This effect was suppressed by AGI (P<0.05). CONCLUSIONS NADPH oxidase-dependent formation of ROS may mediate the TGF-β1-dependent EMT in RPMCs. AGI could inhibit this process, providing a theoretical basis for AGI in the prevention of peritoneal fibrosis.
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Affiliation(s)
- Xiao-xian Liu
- Department of Nephrology, Zhejiang Provincial Hospital of Integrated Chinese and Western Medicine, Hangzhou, 310003, China
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88
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Fernandez IE, Eickelberg O. New cellular and molecular mechanisms of lung injury and fibrosis in idiopathic pulmonary fibrosis. Lancet 2012; 380:680-8. [PMID: 22901889 DOI: 10.1016/s0140-6736(12)61144-1] [Citation(s) in RCA: 321] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Idiopathic pulmonary fibrosis is a serious and progressive chronic lung disease that is characterised by altered cellular composition and homoeostasis in the peripheral lung, leading to excessive accumulation of extracellular matrix and, ultimately, loss of lung function. It is the interstitial pneumonia with the worst prognosis--mortality 3-5 years after diagnosis is 50%. During the past decade, researchers have described several novel cellular and molecular mechanisms and signalling pathways implicated in the pathogenesis of idiopathic pulmonary fibrosis, resulting in the identification of new therapeutic targets. These advances will hopefully result in increased survival rates and improved quality of life for patients with this disorder in future.
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Affiliation(s)
- Isis E Fernandez
- Comprehensive Pneumology Centre, University Hospital of the Ludwig-Maximilians University Munich, Munich, Germany
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89
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Meuten T, Hickey A, Franklin K, Grossi B, Tobias J, Newman DR, Jennings SH, Correa M, Sannes PL. WNT7B in fibroblastic foci of idiopathic pulmonary fibrosis. Respir Res 2012; 13:62. [PMID: 22838404 PMCID: PMC3479038 DOI: 10.1186/1465-9921-13-62] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 07/17/2012] [Indexed: 12/29/2022] Open
Abstract
Background Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial pneumonia causing a loss of respiratory surface area due to a proliferative fibrotic response involving hyperplastic, hypertrophic, and metaplastic epithelium, cystic honeycomb change, septal expansion, and variable inflammation. Wnt (wingless) signaling glycoproteins are known to be involved in lung development and tissue repair, and are up-regulated in patients with IPF. Based on previous qRT-PCR data showing increased Wnt7B in lungs of IPF patients, a systematic, quantitative examination of its tissue site distribution was undertaken. Methods Tissue samples from the Lung Tissue Research Consortium (LTRC) of 39 patients diagnosed with mild to severe IPF/usual interstitial pneumonia (UIP) and 19 normal patients were examined for the immunolocalization of Wnt7B. Results In normal lung, moderate Wnt7B reactivity was confined to airway epithelium, smooth muscle of airways and vasculature, and macrophages. IPF lung showed strong Wnt7B reactivity in fibroblastic foci, dysplastic airway and alveolar epithelium, and in highly discrete subepithelial, basement membrane-associated regions. All reactive sites were sized and counted relative to specific microscopic regions. Those in the subepithelial sites were found in significantly greater numbers and larger relative area compared with the others. No reactive sites were present in normal patient controls. Conclusions The results demonstrate Wnt7B to be expressed at high concentrations in regions of active hyperplasia, metaplasia, and fibrotic change in IPF patients. In this context and its previously established biologic activities, Wnt7B would be expected to be of potential importance in the pathogenesis of IPF.
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Affiliation(s)
- Travis Meuten
- Departments of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
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90
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O'Donoghue RJJ, Knight DA, Richards CD, Prêle CM, Lau HL, Jarnicki AG, Jones J, Bozinovski S, Vlahos R, Thiem S, McKenzie BS, Wang B, Stumbles P, Laurent GJ, McAnulty RJ, Rose-John S, Zhu HJ, Anderson GP, Ernst MR, Mutsaers SE. Genetic partitioning of interleukin-6 signalling in mice dissociates Stat3 from Smad3-mediated lung fibrosis. EMBO Mol Med 2012; 4:939-51. [PMID: 22684844 PMCID: PMC3491826 DOI: 10.1002/emmm.201100604] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/16/2012] [Accepted: 05/09/2012] [Indexed: 12/19/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a fatal disease that is unresponsive to current therapies and characterized by excessive collagen deposition and subsequent fibrosis. While inflammatory cytokines, including interleukin (IL)-6, are elevated in IPF, the molecular mechanisms that underlie this disease are incompletely understood, although the development of fibrosis is believed to depend on canonical transforming growth factor (TGF)-β signalling. We examined bleomycin-induced inflammation and fibrosis in mice carrying a mutation in the shared IL-6 family receptor gp130. Using genetic complementation, we directly correlate the extent of IL-6-mediated, excessive Stat3 activity with inflammatory infiltrates in the lung and the severity of fibrosis in corresponding gp130757F mice. The extent of fibrosis was attenuated in B lymphocyte-deficient gp130757F;µMT−/− compound mutant mice, but fibrosis still occurred in their Smad3−/− counterparts consistent with the capacity of excessive Stat3 activity to induce collagen 1α1 gene transcription independently of canonical TGF-β/Smad3 signalling. These findings are of therapeutic relevance, since we confirmed abundant STAT3 activation in fibrotic lungs from IPF patients and showed that genetic reduction of Stat3 protected mice from bleomycin-induced lung fibrosis.
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Affiliation(s)
- Robert J J O'Donoghue
- Ludwig Institute for Cancer Research, Melbourne - Parkville Branch, Parkville, Victoria, Australia
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91
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Mehrad B, Strieter RM. Fibrocytes and the pathogenesis of diffuse parenchymal lung disease. FIBROGENESIS & TISSUE REPAIR 2012; 5:S22. [PMID: 23259468 PMCID: PMC3368792 DOI: 10.1186/1755-1536-5-s1-s22] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fibrosis is fundamental to the pathogenesis of many chronic lung diseases, including some lung infections, airway diseases such as bronchiectasis and asthma, and most of the diffuse parenchymal lung diseases. Idiopathic pulmonary fibrosis, the prototypical fibrotic lung disease, is amongst the most common diffuse parenchymal lung diseases and is characterized by progressive decline in lung function and premature death from respiratory failure. The clinical management of patients with this illness is hampered by our current inability to predict clinical deterioration and lack of an effective therapy. Fibrocytes are a population of bone marrow-derived circulating progenitor cells that home to injured tissues and differentiate into fibroblasts and myofibroblasts, thus contributing to scar formation. We summarize the evidence supporting the role of these cells in the pathogenesis of fibrotic lung diseases.
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Affiliation(s)
- Borna Mehrad
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Robert M Strieter
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
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92
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Nuovo GJ, Hagood JS, Magro CM, Chin N, Kapil R, Davis L, Marsh CB, Folcik VA. The distribution of immunomodulatory cells in the lungs of patients with idiopathic pulmonary fibrosis. Mod Pathol 2012; 25:416-33. [PMID: 22037258 PMCID: PMC3270219 DOI: 10.1038/modpathol.2011.166] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We have characterized the immune system involvement in the disease processes of idiopathic pulmonary fibrosis in novel ways. To do so, we analyzed lung tissue from 21 cases of idiopathic pulmonary fibrosis and 21 (non-fibrotic, non-cancerous) controls for immune cell and inflammation-related markers. The immunohistochemical analysis of the tissue was grouped by patterns of severity in disease pathology. There were significantly greater numbers of CD68(+) and CD80(+) cells and significantly fewer CD3(+), CD4(+), and CD45RO(+) cells in areas of relatively (histologically) normal lung in biopsy samples from idiopathic pulmonary fibrosis patients compared with controls. In zones of active disease, characterized by epithelial cell regeneration and fibrosis, there were significantly more cells expressing CD4, CD8, CD20, CD68, CD80, chemokine receptor 6 (CCR6), S100, IL-17, tumor necrosis factor-α, and retinoic acid-related orphan receptors compared with histologically normal lung areas from idiopathic pulmonary fibrosis patients. Inflammation was implicated in these active regions by the cells that expressed retinoid orphan receptor-α, -β, and -γ, CCR6, and IL-17. The regenerating epithelial cells predominantly expressed these pro-inflammatory molecules, as evidenced by co-expression analyses with epithelial cytokeratins. Macrophages in pseudo-alveoli and CD3(+) T cells in the fibrotic interstitium also expressed IL-17. Co-expression of IL-17 with retinoid orphan receptors and epithelial cytoskeletal proteins, CD68, and CD3 in epithelial cells, macrophages, and T-cells, respectively, confirmed the production of IL-17 by these cell types. There was little staining for forkhead box p3, CD56, or CD34 in any idiopathic pulmonary fibrosis lung regions. The fibrotic regions had fewer immune cells overall. In summary, our study shows participation of innate and adaptive mononuclear cells in active-disease regions of idiopathic pulmonary fibrosis lung, where the regenerating epithelial cells appear to propagate inflammation. The regenerative mechanisms become skewed to ultimately result in lethal, fibrotic restriction of lung function.
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Affiliation(s)
- Gerard J. Nuovo
- The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA
| | - James S. Hagood
- Pediatric Respiratory Medicine, University of California-San Diego, and Rady Children’s Hospital of San Diego, CA, USA
| | - Cynthia M. Magro
- Anatomic Pathology and Clinical Pathology Dermatopathology Service, Weill College of Medicine of Cornell University and New York Presbyterian Hospital, NY, USA
| | - Nena Chin
- Accurate Diagnostic Labs, South Plainfield, NJ, USA
| | - Rubina Kapil
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH, USA
| | - Luke Davis
- College of Dentistry, The Ohio State University Medical Center, Columbus, OH, USA
| | - Clay B. Marsh
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH, USA
| | - Virginia A. Folcik
- Department of Internal Medicine, The Ohio State University Medical Center, Columbus, OH, USA
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93
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Leslie KO. Idiopathic pulmonary fibrosis may be a disease of recurrent, tractional injury to the periphery of the aging lung: a unifying hypothesis regarding etiology and pathogenesis. Arch Pathol Lab Med 2011; 136:591-600. [PMID: 22136526 DOI: 10.5858/arpa.2011-0511-oa] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT Idiopathic pulmonary fibrosis is a progressive, fatal lung disease occurring in older individuals. Despite 50 years of accrued data about the disease, little progress has been made in slowing functional loss or in decreasing patient mortality. OBJECTIVE To present a novel hypothesis on the etiology and pathogenesis of idiopathic pulmonary fibrosis. DESIGN Published data are reviewed regarding the epidemiology, clinical presentation, natural history, radiologic findings, and pathologic findings in patients with idiopathic pulmonary fibrosis. RESULTS Patients with idiopathic pulmonary fibrosis may be predisposed genetically to tractional injury to the peripheral lung. The result is recurrent damage to the epithelial-mesenchymal interface, preferentially at the outer edges of the basilar lung lobules where tractional stress is high during inspiration, compliance is relatively low, and there is a greater tendency for alveolar collapse at end-expiration. A distinctive "reticular network of injury" (the fibroblast focus) forms, attended by a prolonged phase of wound repair (tear and slow repair). Discrete areas of alveolar collapse are observed in scar at the periphery of the lung lobules. The cycle repeats over many years resulting in progressive fibrous remodeling and replacement of the alveoli in a lobule by bronchiolar cysts surrounded by scar (honeycomb lung). Abnormalities in surfactant function are proposed as a potential mechanism of initial lung damage. Age of onset may be a function of a required threshold of environmental exposures (eg, cigarette smoking) or other comorbid injury to the aging lung. CONCLUSIONS Evidence supporting this hypothesis is presented and potential mechanisms are discussed. A potential role for contributing cofactors is presented.
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Affiliation(s)
- Kevin O Leslie
- Department of Laboratory Medicineand Pathology, Mayo Clinic Arizona, 13400 East Shea Blvd, Scottsdale, AZ 85259, USA.
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94
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Uzunhan Y, Nunes H, Gille T, Bron C, Planès C, Valeyre D. Innovations thérapeutiques de la fibrose pulmonaire idiopathique. Presse Med 2011; 40:1100-12. [DOI: 10.1016/j.lpm.2011.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 07/19/2011] [Indexed: 02/06/2023] Open
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95
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Lovgren AK, Kovacs JJ, Xie T, Potts EN, Li Y, Foster WM, Liang J, Meltzer EB, Jiang D, Lefkowitz RJ, Noble PW. β-arrestin deficiency protects against pulmonary fibrosis in mice and prevents fibroblast invasion of extracellular matrix. Sci Transl Med 2011; 3:74ra23. [PMID: 21411739 DOI: 10.1126/scitranslmed.3001564] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Idiopathic pulmonary fibrosis is a progressive disease that causes unremitting extracellular matrix deposition with resulting distortion of pulmonary architecture and impaired gas exchange. β-Arrestins regulate G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors through receptor desensitization while also acting as signaling scaffolds to facilitate numerous effector pathways. Here, we examine the role of β-arrestin1 and β-arrestin2 in the pathobiology of pulmonary fibrosis. In the bleomycin-induced mouse lung fibrosis model, loss of either β-arrestin1 or β-arrestin2 resulted in protection from mortality, inhibition of matrix deposition, and protected lung function. Fibrosis was prevented despite preserved recruitment of inflammatory cells and fibroblast chemotaxis. However, isolated lung fibroblasts from bleomycin-treated β-arrestin-null mice failed to invade extracellular matrix and displayed altered expression of genes involved in matrix production and degradation. Furthermore, knockdown of β-arrestin2 in fibroblasts from patients with idiopathic pulmonary fibrosis attenuated the invasive phenotype. These data implicate β-arrestins as mediators of fibroblast invasion and the development of pulmonary fibrosis, and as a potential target for therapeutic intervention in patients with idiopathic pulmonary fibrosis.
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Affiliation(s)
- Alysia Kern Lovgren
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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96
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Triantafillidou C, Manali ED, Magkou C, Sotiropoulou C, Kolilekas LF, Kagouridis K, Rontogianni D, Papiris SA. Medical Research Council dyspnea scale does not relate to fibroblast foci profusion in IPF. Diagn Pathol 2011; 6:28. [PMID: 21466701 PMCID: PMC3083323 DOI: 10.1186/1746-1596-6-28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Accepted: 04/05/2011] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND In Idiopathic pulmonary fibrosis (IPF) irreversibly progressive fibrosing parenchymal damage, leads to defects in mechanics and gas exchange, manifesting with disabling exertional dyspnea. Previous studies have shown a relationship between fibroblast foci (FF) profusion and severity and survival and a relationship between dyspnea grade and severity and outcome. We hypothesized a relationship between Medical Research Council (MRC) dyspnea scale with FF, and a relationship between FF and functional parameters and survival. METHODS We retrospectively reviewed 24 histologically documented IPF patients. Profusion of FF was semiquantitatively evaluated by two scores, Brompton and Michigan. Survival analysis was performed by fitting Cox regression models to examine the relationship of the two scores with survival and the non-parametric Spearman correlation coefficient was calculated to describe the relationships of FF scores with dyspnea scores and functional parameters. RESULTS No statistically significant correlation between FF scores and the MRC scores was observed (p = 0.96 and p = 0.508 respectively). No significant correlation between FF scores and survival (p = 0.438 and p = 0.861 respectively) or any functional parameter was observed. CONCLUSIONS The lack of relationship between the MRC dyspnea scale and the FF might relate to the fact that dyspnea in IPF better reflects the overall of lung damage and its related consequences on mechanics and gas exchange whereas FF, one of its histological hallmarks, may not reflect its entire histology derangement also constrained by the geographically limited sampled tissue. This might be also valid for the observed lack of association between FF and survival or functional parameters.
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Affiliation(s)
- Christina Triantafillidou
- 2nd Pulmonary Department, Attikon University Hospital, National and Kapodistrian University of Athens, Greece
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97
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Pandit KV, Milosevic J, Kaminski N. MicroRNAs in idiopathic pulmonary fibrosis. Transl Res 2011; 157:191-9. [PMID: 21420029 DOI: 10.1016/j.trsl.2011.01.012] [Citation(s) in RCA: 245] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 01/16/2011] [Accepted: 01/18/2011] [Indexed: 01/04/2023]
Abstract
In this review, we describe the recent advances in the understanding of the role of microRNAs in idiopathic pulmonary fibrosis (IPF), a chronic progressive and lethal fibrotic lung disease. Approximately 10% of the microRNAs are significantly changed in IPF lungs. Among the significantly downregulated microRNAs are members of let-7, mir-29, and mir-30 families as well as miR-17∼92 cluster among the upregulated mir-155 and mir-21. Downregulation of let-7 family members leads to changes consistent with epithelial mesenchymal transition in lung epithelial cells both in vitro and in vivo, whereas inhibition of mir-21 modulates fibrosis in the bleomycin model of lung fibrosis. Perturbations of mir-155 and mir-29 have profibrotic effects in vitro but have not yet been assessed in vivo in the context of lung fibrosis. A recurrent global theme is that many microRNAs studied in IPF are both regulated by transforming growth factor β1 (TGFβ1) and regulate TGFβ1 signaling pathway by their target genes. As a result, their aberrant expression leads to a release of inhibitions on the TGFβ1 pathway and to the creation of feed-forward loops. Coanalysis of published microRNA and gene expression microarray data in IPF reveals enrichment of the TGFβ1, Wnt, sonic hedgehog, p53, and vascular endothelial growth factor pathways and complex regulatory networks. The changes in microRNA expression in the IPF lung and the evidence for their role in the fibrosis suggest that microRNAs should be evaluated as therapeutic targets in IPF.
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Affiliation(s)
- Kusum V Pandit
- Dorothy P. and Richard P. Simmons Center for Interstitial Lung Disease, Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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98
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Bronchial blood supply after lung transplantation without bronchial artery revascularization. Curr Opin Organ Transplant 2011; 15:563-7. [PMID: 20689435 DOI: 10.1097/mot.0b013e32833deca9] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW This review discusses how the bronchial artery circulation is interrupted following lung transplantation and what may be the long-term complications of compromising systemic blood flow to allograft airways. RECENT FINDINGS Preclinical and clinical studies have shown that the loss of airway microcirculations is highly associated with the development of airway hypoxia and an increased susceptibility to chronic rejection. SUMMARY The bronchial artery circulation has been highly conserved through evolution. Current evidence suggests that the failure to routinely perform bronchial artery revascularization at the time of lung transplantation may predispose patients to develop the bronchiolitis obliterans syndrome.
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99
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Bocchino M, Agnese S, Fagone E, Svegliati S, Grieco D, Vancheri C, Gabrielli A, Sanduzzi A, Avvedimento EV. Reactive oxygen species are required for maintenance and differentiation of primary lung fibroblasts in idiopathic pulmonary fibrosis. PLoS One 2010; 5:e14003. [PMID: 21103368 PMCID: PMC2982828 DOI: 10.1371/journal.pone.0014003] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 10/18/2010] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal illness whose pathogenesis remains poorly understood. Recent evidence suggests oxidative stress as a key player in the establishment/progression of lung fibrosis in animal models and possibly in human IPF. The aim of the present study was to characterize the cellular phenotype of fibroblasts derived from IPF patients and identify underlying molecular mechanisms. METHODOLOGY/PRINCIPAL FINDINGS We first analyzed the baseline differentiation features and growth ability of primary lung fibroblasts derived from 7 histology proven IPF patients and 4 control subjects at different culture passages. Then, we focused on the redox state and related molecular pathways of IPF fibroblasts and investigated the impact of oxidative stress in the establishment of the IPF phenotype. IPF fibroblasts were differentiated into alpha-smooth muscle actin (SMA)-positive myofibroblasts, displayed a pro-fibrotic phenotype as expressing type-I collagen, and proliferated lower than controls cells. The IPF phenotype was inducible upon oxidative stress in control cells and was sensitive to ROS scavenging. IPF fibroblasts also contained large excess of reactive oxygen species (ROS) due to the activation of an NADPH oxidase-like system, displayed higher levels of tyrosine phosphorylated proteins and were more resistant to oxidative-stress induced cell death. Interestingly, the IPF traits disappeared with time in culture, indicating a transient effect of the initial trigger. CONCLUSIONS/SIGNIFICANCE Robust expression of α-SMA and type-I collagen, high and uniformly-distributed ROS levels, resistance to oxidative-stress induced cell death and constitutive activation of tyrosine kinase(s) signalling are distinctive features of the IPF phenotype. We suggest that this phenotype can be used as a model to identify the initial trigger of IPF.
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Affiliation(s)
- Marialuisa Bocchino
- Dipartimento di Medicina Clinica e Sperimentale, Sezione di Malattie dell'Apparato Respiratorio, Università Federico II, Napoli, Italy.
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Borensztajn K, Bresser P, van der Loos C, Bot I, van den Blink B, den Bakker MA, Daalhuisen J, Groot AP, Peppelenbosch MP, von der Thüsen JH, Spek CA. Protease-activated receptor-2 induces myofibroblast differentiation and tissue factor up-regulation during bleomycin-induced lung injury: potential role in pulmonary fibrosis. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2753-64. [PMID: 20971733 DOI: 10.2353/ajpath.2010.091107] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Idiopathic pulmonary fibrosis constitutes the most devastating form of fibrotic lung disorders and remains refractory to current therapies. The coagulation cascade is frequently activated during pulmonary fibrosis, but this observation has so far resisted a mechanistic explanation. Recent data suggest that protease-activated receptor (PAR)-2, a receptor activated by (among others) coagulation factor (F)Xa, plays a key role in fibrotic disease; consequently, we assessed the role of PAR-2 in the development of pulmonary fibrosis in this study. We show that PAR-2 is up-regulated in the lungs of patients with idiopathic pulmonary fibrosis and that bronchoalveolar lavage fluid from these patients displays increased procoagulant activity that triggers fibroblast survival. Using a bleomycin model of pulmonary fibrosis, we show that bleomycin induces PAR-2 expression, as well as both myofibroblast differentiation and collagen synthesis. In PAR-2-/- mice, both the extent and severity of fibrotic lesions are reduced, whereas myofibroblast differentiation is diminished and collagen expression is decreased. Moreover, fibrin deposition in the lungs of fibrotic PAR-2-/- mice is reduced compared with wild-type mice due to differential tissue factor expression in response to bleomycin. Taken together, these results suggest an important role for PAR-2 in the development of pulmonary fibrosis, and the inhibition of the PAR-2-coagulation axis may provide a novel therapeutic approach to treat this devastating disease.
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Affiliation(s)
- Keren Borensztajn
- Center for Experimental and Molecular Medicine, Academic Medical Center, Meibergdreef 9, NL-1105 AZ, Amsterdam, The Netherlands.
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