RESUMO
Rationale: Idiopathic pulmonary fibrosis (IPF) affects the subpleural lung but is considered to spare small airways. Micro-computed tomography (micro-CT) studies demonstrated small airway reduction in end-stage IPF explanted lungs, raising questions about small airway involvement in early-stage disease. Endobronchial optical coherence tomography (EB-OCT) is a volumetric imaging modality that detects microscopic features from subpleural to proximal airways. Objectives: In this study, EB-OCT was used to evaluate small airways in early IPF and control subjects in vivo. Methods: EB-OCT was performed in 12 subjects with IPF and 5 control subjects (matched by age, sex, smoking history, height, and body mass index). Subjects with IPF had early disease with mild restriction (FVC: 83.5% predicted), which was diagnosed per current guidelines and confirmed by surgical biopsy. EB-OCT volumetric imaging was acquired bronchoscopically in multiple, distinct, bilateral lung locations (total: 97 sites). IPF imaging sites were classified by severity into affected (all criteria for usual interstitial pneumonia present) and less affected (some but not all criteria for usual interstitial pneumonia present). Bronchiole count and small airway stereology metrics were measured for each EB-OCT imaging site. Measurements and Main Results: Compared with the number of bronchioles in control subjects (mean = 11.2/cm3; SD = 6.2), there was significant bronchiole reduction in subjects with IPF (42% loss; mean = 6.5/cm3; SD = 3.4; P = 0.0039), including in IPF affected (48% loss; mean: 5.8/cm3; SD: 2.8; P < 0.00001) and IPF less affected (33% loss; mean: 7.5/cm3; SD: 4.1; P = 0.024) sites. Stereology metrics showed that IPF-affected small airways were significantly larger, more distorted, and more irregular than in IPF-less affected sites and control subjects. IPF less affected and control airways were statistically indistinguishable for all stereology parameters (P = 0.36-1.0). Conclusions: EB-OCT demonstrated marked bronchiolar loss in early IPF (between 30% and 50%), even in areas minimally affected by disease, compared with matched control subjects. These findings support small airway disease as a feature of early IPF, providing novel insight into pathogenesis and potential therapeutic targets.
Assuntos
Broncoscopia , Fibrose Pulmonar Idiopática , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Masculino , Feminino , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/patologia , Pessoa de Meia-Idade , Idoso , Broncoscopia/métodos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Estudos de Casos e ControlesRESUMO
Idiopathic pulmonary fibrosis (IPF) is a particularly deadly form of pulmonary fibrosis of unknown cause. In patients with IPF, high serum and lung concentrations of CHI3L1 (chitinase 3 like 1) can be detected and are associated with poor survival. However, the roles of CHI3L1 in these diseases have not been fully elucidated. We hypothesize that CHI3L1 interacts with CRTH2 (chemoattractant receptor-homologous molecule expressed on T-helper type 2 cells) to stimulate profibrotic macrophage differentiation and the development of pulmonary fibrosis and that circulating blood monocytes from patients with IPF are hyperresponsive to CHI3L1-CRTH2 signaling. We used murine pulmonary fibrosis models to investigate the role of CRTH2 in profibrotic macrophage differentiation and fibrosis development and primary human peripheral blood mononuclear cell culture to detect the difference of monocytes in the responses to CHI3L1 stimulation and CRTH2 inhibition between patients with IPF and normal control subjects. Our results showed that null mutation or small-molecule inhibition of CRTH2 prevents the development of pulmonary fibrosis in murine models. Furthermore, CHI3L1 stimulation induces a greater increase in CD206 expression in IPF monocytes than control monocytes. These results demonstrated that monocytes from patients with IPF appear to be hyperresponsive to CHI3L1 stimulation. These studies support targeting the CHI3L1-CRTH2 pathway as a promising therapeutic approach for IPF and that the sensitivity of blood monocytes to CHI3L1-induced profibrotic differentiation may serve as a biomarker that predicts responsiveness to CHI3L1- or CRTH2-based interventions.
Assuntos
Fibrose Pulmonar Idiopática , Leucócitos Mononucleares , Animais , Fibrose , Humanos , Fibrose Pulmonar Idiopática/genética , Pulmão , Macrófagos , CamundongosRESUMO
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease which leads to significant morbidity and mortality from respiratory failure. The two drugs currently approved for clinical use slow the rate of decline in lung function but have not been shown to halt disease progression or reverse established fibrosis. Thus, new therapeutic targets are needed. Endothelial injury and the resultant vascular permeability are critical components in the response to tissue injury and are present in patients with IPF. However, it remains unclear how vascular permeability affects lung repair and fibrosis following injury. Lipid mediators such as sphingosine-1-phosphate (S1P) are known to regulate multiple homeostatic processes in the lung including vascular permeability. We demonstrate that endothelial cell-(EC) specific deletion of the S1P receptor 1 (S1PR1) in mice (EC-S1pr1-/-) results in increased lung vascular permeability at baseline. Following a low-dose intratracheal bleomycin challenge, EC-S1pr1-/- mice had increased and persistent vascular permeability compared with wild-type mice, which was strongly correlated with the amount and localization of resulting pulmonary fibrosis. EC-S1pr1-/- mice also had increased immune cell infiltration and activation of the coagulation cascade within the lung. However, increased circulating S1P ligand in ApoM-overexpressing mice was insufficient to protect against bleomycin-induced pulmonary fibrosis. Overall, these data demonstrate that endothelial cell S1PR1 controls vascular permeability in the lung, is associated with changes in immune cell infiltration and extravascular coagulation, and modulates the fibrotic response to lung injury.
Assuntos
Permeabilidade Capilar , Células Endoteliais/metabolismo , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/patologia , Receptores de Esfingosina-1-Fosfato/metabolismo , Animais , Bleomicina , Coagulação Sanguínea , Deleção de Genes , Fibrose Pulmonar Idiopática/sangue , Pulmão/irrigação sanguínea , Pulmão/patologia , Lisofosfolipídeos/sangue , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , RNA-Seq , Análise de Célula Única , Esfingosina/análogos & derivados , Esfingosina/sangueRESUMO
BACKGROUND: Many patients with polymyositis (PM) or dermatomyositis (DM) have circulating myositis-specific antibodies (MSAs). Interstitial lung disease (ILD) is a common manifestation of PM/DM, and it can even precede the onset of characteristic muscle or skin manifestations. Furthermore, there appear to be some patients with ILD and circulating MSAs who do not develop muscle or skin disease even after prolonged follow-up. We sought to determine whether ILD is equally or more common than myositis or dermatitis at the time of initial detection of MSAs. METHODS: We identified all patients found to have circulating MSAs at our institution over a 4-year period and assessed for the presence of lung, muscle, and skin disease at the time of initial detection of MSAs. Among those found to have ILD, we compared demographic and clinical features, chest CT scan findings, and outcomes between those with PM/DM-associated ILD and those with ILD but no muscle or skin disease. RESULTS: A total of 3078 patients were tested for MSAs, and of these 40 were positive. Nine different MSAs were detected, with anti-histidyl tRNA synthetase (anti-Jo-1) being the most common (35% of MSAs). Among patients with positive MSAs, 86% were found to have ILD, compared to 39% and 28% with muscle and skin involvement, respectively (p < 0.001). Fifty percent of all MSA-positive patients had isolated ILD, with no evidence of muscle or skin disease. Those with isolated ILD were more likely to be older and have fibrotic changes on chest CT, less likely to receive immunomodulatory therapy, and had worse overall survival. CONCLUSIONS: In this study we found that individuals with circulating MSAs were more likely to have ILD than classic muscle or skin manifestations of PM/DM at the time of initial detection of MSAs. Our findings suggest that the presence of ILD should be considered a disease-defining manifestation in the presence of MSAs and incorporated into classification criteria for PM/DM.
Assuntos
Autoanticorpos/imunologia , Doenças Pulmonares Intersticiais/epidemiologia , Doenças Pulmonares Intersticiais/imunologia , Miosite/imunologia , Corticosteroides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Miosite/complicações , Miosite/epidemiologia , Rhode Island/epidemiologiaRESUMO
Idiopathic pulmonary fibrosis (IPF) is thought to result from aberrant tissue repair processes in response to chronic or repetitive lung injury. The origin and nature of the injury, as well as its cellular and molecular targets, are likely heterogeneous, which complicates accurate pre-clinical modelling of the disease and makes therapeutic targeting a challenge. Efforts are underway to identify central pathways in fibrogenesis which may allow targeting of aberrant repair processes regardless of the initial injury stimulus. Dysregulated endothelial permeability and vascular leak have long been studied for their role in acute lung injury and repair. Evidence that these processes are of importance to the pathogenesis of fibrotic lung disease is growing. Endothelial permeability is increased in non-fibrosing lung diseases, but it resolves in a self-limited fashion in conditions such as bacterial pneumonia and acute respiratory distress syndrome. In progressive fibrosing diseases such as IPF, permeability appears to persist, however, and may also predict mortality. In this hypothesis-generating review, we summarise available data on the role of endothelial permeability in IPF and focus on the deleterious consequences of sustained endothelial hyperpermeability in response to and during pulmonary inflammation and fibrosis. We propose that persistent permeability and vascular leak in the lung have the potential to establish and amplify the pro-fibrotic environment. Therapeutic interventions aimed at recognising and "plugging" the leak may therefore be of significant benefit for preventing the transition from lung injury to fibrosis and should be areas for future research.
Assuntos
Permeabilidade Capilar , Fibrose Pulmonar Idiopática , Fibrose , Humanos , Fibrose Pulmonar Idiopática/patologia , Pulmão/patologiaRESUMO
Hermansky-Pudlak syndrome (HPS) comprises a group of inherited disorders caused by mutations that alter the function of lysosome-related organelles. Pulmonary fibrosis is the major cause of morbidity and mortality in HPS-1 and HPS-4 patients. However, the mechanisms that underlie the exaggerated injury and fibroproliferative repair responses in HPS have not been adequately defined. In particular, although Galectin-3 (Gal-3) is dysregulated in HPS, its roles in the pathogenesis of HPS have not been adequately defined. In addition, although chitinase 3-like 1 (CHI3L1) and its receptors play major roles in the injury and repair responses in HPS, the ability of Gal-3 to interact with or alter the function of these moieties has not been evaluated. In this article, we demonstrate that Gal-3 accumulates in exaggerated quantities in bronchoalveolar lavage fluids, and traffics abnormally and accumulates intracellularly in lung fibroblasts and macrophages from bleomycin-treated pale ear, HPS-1-deficient mice. We also demonstrate that Gal-3 drives epithelial apoptosis when in the extracellular space, and stimulates cell proliferation and myofibroblast differentiation when accumulated in fibroblasts and M2-like differentiation when accumulated in macrophages. Biophysical and signaling evaluations also demonstrated that Gal-3 physically interacts with IL-13Rα2 and CHI3L1, and competes with TMEM219 for IL-13Rα2 binding. By doing so, Gal-3 diminishes the antiapoptotic effects of and the antiapoptotic signaling induced by CHI3L1 in epithelial cells while augmenting macrophage Wnt/ß-catenin signaling. Thus, Gal-3 contributes to the exaggerated injury and fibroproliferative repair responses in HPS by altering the antiapoptotic and fibroproliferative effects of CHI3L1 and its receptor complex in a tissue compartment-specific manner.
Assuntos
Proteína 1 Semelhante à Quitinase-3/metabolismo , Galectina 3/metabolismo , Síndrome de Hermanski-Pudlak/metabolismo , Pulmão/metabolismo , Animais , Apoptose/efeitos dos fármacos , Bleomicina/farmacologia , Líquido da Lavagem Broncoalveolar/química , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Pulmão/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fibrose Pulmonar/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/metabolismoRESUMO
Pulmonary fibrosis is thought to result from dysregulated wound repair after repetitive lung injury. Many cellular responses to injury involve rearrangements of the actin cytoskeleton mediated by the two isoforms of the Rho-associated coiled-coil-forming protein kinase (ROCK), ROCK1 and ROCK2. In addition, profibrotic mediators such as transforming growth factor-ß, thrombin, and lysophosphatidic acid act through receptors that activate ROCK. Inhibition of ROCK activation may be a potent therapeutic strategy for human pulmonary fibrosis. Pharmacological inhibition of ROCK using nonselective ROCK inhibitors has been shown to prevent fibrosis in animal models; however, the specific roles of each ROCK isoform are poorly understood. Furthermore, the pleiotropic effects of this kinase have raised concerns about on-target adverse effects of ROCK inhibition such as hypotension. Selective inhibition of one isoform might be a better-tolerated strategy. In the present study, we used a genetic approach to determine the roles of ROCK1 and ROCK2 in a mouse model of bleomycin-induced pulmonary fibrosis. Using ROCK1- or ROCK2-haploinsufficient mice, we found that reduced expression of either ROCK1 or ROCK2 was sufficient to protect them from bleomycin-induced pulmonary fibrosis. In addition, we found that both isoforms contribute to the profibrotic responses of epithelial cells, endothelial cells, and fibroblasts. Interestingly, ROCK1- and ROCK2-haploinsufficient mice exhibited similar protection from bleomycin-induced vascular leak, myofibroblast differentiation, and fibrosis; however, ROCK1-haploinsufficient mice demonstrated greater attenuation of epithelial cell apoptosis. These findings suggest that selective inhibition of either ROCK isoform has the potential to be an effective therapeutic strategy for pulmonary fibrosis.
Assuntos
Fibroblastos/enzimologia , Pulmão/enzimologia , Fibrose Pulmonar/prevenção & controle , Quinases Associadas a rho/metabolismo , Animais , Apoptose , Bleomicina , Permeabilidade Capilar , Diferenciação Celular , Modelos Animais de Doenças , Células Endoteliais/enzimologia , Células Endoteliais/patologia , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Fibroblastos/patologia , Haploinsuficiência , Humanos , Pulmão/patologia , Camundongos Knockout , Miofibroblastos/enzimologia , Miofibroblastos/patologia , Fibrose Pulmonar/enzimologia , Fibrose Pulmonar/genética , Fibrose Pulmonar/patologia , Quinases Associadas a rho/deficiência , Quinases Associadas a rho/genéticaRESUMO
Idiopathic pulmonary fibrosis (IPF) is the most common of the idiopathic interstitial pneumonias and is characterised by progressive accumulation of scar tissue in the lungs. The objective of this study was to describe the current mortality rates due to IPF in Europe, based on the World Health Organization (WHO) mortality database.We used country-level data for IPF mortality, identified in the WHO mortality database using International Classification of Diseases 10th Edition (ICD-10) codes, for the period 2001-2013. Joinpoint analysis was performed to describe trends throughout the observation period.The median mortality was 3.75 per 100â000 (interquartile range (IQR) 1.37-5.30) and 1.50 per 100â000 (IQR 0.65-2.02) for males and females, respectively. IPF mortality increased in the majority of the European Union (EU) countries with the exceptions of Denmark, Croatia, Austria and Romania. There was a significant disparity in rates across Europe, in the range 0.41-12.1 per 100â000 for men and 0.24-5.63 per 100â000 for women. The most notable increases were observed in the United Kingdom and Finland. Rates were also substantially higher in males, with sex disparity increasing across the period.The reported IPF mortality appears to be increasing across the EU; however, there is substantial variation in mortality trends and overall reported mortality rates between countries.
Assuntos
Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/mortalidade , Bases de Dados Factuais , União Europeia , Feminino , Humanos , Pneumonias Intersticiais Idiopáticas/mortalidade , Pneumonias Intersticiais Idiopáticas/patologia , Masculino , Análise de Regressão , Sensibilidade e Especificidade , Organização Mundial da SaúdeRESUMO
Lysophosphatidic acid (LPA) is an important mediator of pulmonary fibrosis. In blood and multiple tumor types, autotaxin produces LPA from lysophosphatidylcholine (LPC) via lysophospholipase D activity, but alternative enzymatic pathways also exist for LPA production. We examined the role of autotaxin (ATX) in pulmonary LPA production during fibrogenesis in a bleomycin mouse model. We found that bleomycin injury increases the bronchoalveolar lavage (BAL) fluid levels of ATX protein 17-fold. However, the LPA and LPC species that increase in BAL of bleomycin-injured mice were discordant, inconsistent with a substrate-product relationship between LPC and LPA in pulmonary fibrosis. LPA species with longer chain polyunsaturated acyl groups predominated in BAL fluid after bleomycin injury, with 22:5 and 22:6 species accounting for 55 and 16% of the total, whereas the predominant BAL LPC species contained shorter chain, saturated acyl groups, with 16:0 and 18:0 species accounting for 56 and 14% of the total. Further, administration of the potent ATX inhibitor PAT-048 to bleomycin-challenged mice markedly decreased ATX activity systemically and in the lung, without effect on pulmonary LPA or fibrosis. Therefore, alternative ATX-independent pathways are likely responsible for local generation of LPA in the injured lung. These pathways will require identification to therapeutically target LPA production in pulmonary fibrosis.-Black, K. E., Berdyshev, E., Bain, G., Castelino, F. V., Shea, B. S., Probst, C. K., Fontaine, B. A., Bronova, I., Goulet, L., Lagares, D., Ahluwalia, N., Knipe, R. S., Natarajan, V., Tager, A. M. Autotaxin activity increases locally following lung injury, but is not required for pulmonary lysophosphatidic acid production or fibrosis.
Assuntos
Lesão Pulmonar/induzido quimicamente , Pulmão/metabolismo , Lisofosfolipídeos/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Fibrose Pulmonar/metabolismo , Animais , Antibióticos Antineoplásicos/toxicidade , Benzoatos/farmacologia , Bleomicina/toxicidade , Regulação da Expressão Gênica/fisiologia , Lesão Pulmonar/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Diester Fosfórico Hidrolases/genética , Fibrose Pulmonar/induzido quimicamenteRESUMO
Idiopathic pulmonary fibrosis (IPF) is a devastating disease, with a median survival as short as 3 years from the time of diagnosis and no pharmacological therapies yet approved by the U.S. Food and Drug Administration. To address the great unmet need for effective IPF therapy, a number of new drugs have recently been, or are now being, evaluated in clinical trials. The rationales for most of these therapeutic candidates are based on the current paradigm of IPF pathogenesis, in which recurrent injury to the alveolar epithelium is believed to drive aberrant wound healing responses, resulting in fibrosis rather than repair. Here we discuss drugs in recently completed or currently ongoing phase II and III IPF clinical trials in the context of their putative mechanisms of action and the aberrant repair processes they are believed to target: innate immune activation and polarization, fibroblast accumulation and myofibroblast differentiation, or extracellular matrix deposition and stiffening. Placed in this context, the positive results of recently completed trials of pirfenidone and nintedanib, and results that will come from ongoing trials of other agents, should provide valuable insights into the still-enigmatic pathogenesis of this disease, in addition to providing benefits to patients with IPF.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Indóis/uso terapêutico , Piridonas/uso terapêutico , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Inibidores Enzimáticos/farmacologia , Humanos , Fibrose Pulmonar Idiopática/etiologia , Fibrose Pulmonar Idiopática/fisiopatologia , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Indóis/farmacologia , Piridonas/farmacologia , Cicatrização/efeitos dos fármacosRESUMO
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease with no effective medical therapies. Recent research has focused on identifying the biological processes essential to the development and progression of fibrosis, and on the mediators driving these processes. Lysophosphatidic acid (LPA), a biologically active lysophospholipid, is one such mediator. LPA has been found to be elevated in bronchoalveolar lavage (BAL) fluid of IPF patients, and through interaction with its cell surface receptors, it has been shown to drive multiple biological processes implicated in the development of IPF. Accordingly, the first clinical trial of an LPA receptor antagonist in IPF has recently been initiated. In addition to being a therapeutic target, LPA also has potential to be a biomarker for IPF. There is increasing interest in exhaled breath condensate (EBC) analysis as a non-invasive method for biomarker detection in lung diseases, but to what extent LPA is present in EBC is not known. METHODS: In this study, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to assess for the presence of LPA in the EBC and plasma from 11 IPF subjects and 11 controls. RESULTS: A total of 9 different LPA species were detectable in EBC. Of these, docosatetraenoyl (22:4) LPA was significantly elevated in the EBC of IPF subjects when compared to controls (9.18 pM vs. 0.34 pM; p = 0.001). A total of 13 different LPA species were detectable in the plasma, but in contrast to the EBC, there were no statistically significant differences in plasma LPA species between IPF subjects and controls. CONCLUSIONS: These results demonstrate that multiple LPA species are detectable in EBC, and that 22:4 LPA levels are elevated in the EBC of IPF patients. Further research is needed to determine the significance of this elevation of 22:4 LPA in IPF EBC, as well as its potential to serve as a biomarker for disease severity and/or progression.
Assuntos
Fibrose Pulmonar Idiopática/metabolismo , Lisofosfolipídeos/análise , Idoso , Testes Respiratórios , Feminino , Humanos , MasculinoAssuntos
Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Fibrose Pulmonar Idiopática/patologia , Pulmão/patologia , Pleura/patologia , Diagnóstico Diferencial , Dispneia/etiologia , Tolerância ao Exercício , Feminino , Humanos , Fibrose Pulmonar Idiopática/complicações , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Pneumopatias/diagnóstico , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XAssuntos
Gadolínio , Imageamento por Ressonância Magnética/métodos , Compostos Organometálicos , Fibrose Pulmonar/diagnóstico por imagem , Doenças Vasculares/complicações , Estudos de Casos e Controles , Meios de Contraste , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Fibrose Pulmonar/patologia , Doenças Vasculares/patologiaRESUMO
OBJECTIVE: Enhanced adhesive signaling, including activation of focal adhesion kinase (FAK), is a hallmark of fibroblasts from lung fibrosis patients, and FAK has therefore been hypothesized to be a key mediator of this disease. This study was undertaken to characterize the contribution of FAK to the development of pulmonary fibrosis both in vivo and in vitro. METHODS: FAK expression and activity were analyzed in lung tissue samples from lung fibrosis patients by immunohistochemistry. Mice orally treated with the FAK inhibitor PF-562,271, or with small interfering RNA (siRNA)-mediated silencing of FAK were exposed to intratracheally instilled bleomycin to induce lung fibrosis, and lungs were harvested for histologic and biochemical analysis. Using endothelin 1 (ET-1) as a stimulus, cell adhesion and contraction, as well as profibrotic gene expression, were studied in fibroblasts isolated from wild-type and FAK-deficient mouse embryos. ET-1-mediated FAK activation and gene expression were studied in primary mouse lung fibroblasts, as well as in wild-type and ß1 integrin-deficient mouse fibroblasts. RESULTS: FAK expression and activity were up-regulated in fibroblast foci and remodeled vessels from lung fibrosis patients. Pharmacologic or siRNA-mediated targeting of FAK resulted in marked abrogation of bleomycin-induced lung fibrosis in mice. Loss of FAK impaired the acquisition of a profibrotic phenotype in response to ET-1. Profibrotic gene expression leading to myofibroblast differentiation required cell adhesion, and was driven by JNK activation through ß1 integrin/FAK signaling. CONCLUSION: These results implicate FAK as a central mediator of fibrogenesis, and highlight this kinase as a potential therapeutic target in fibrotic diseases.
Assuntos
Inibidores Enzimáticos/farmacologia , Proteína-Tirosina Quinases de Adesão Focal/antagonistas & inibidores , Indóis/farmacologia , Pulmão/efeitos dos fármacos , Miofibroblastos/efeitos dos fármacos , Fibrose Pulmonar/prevenção & controle , Sulfonamidas/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Endotelina-1/farmacologia , Feminino , Proteína-Tirosina Quinases de Adesão Focal/genética , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Inativação Gênica , Humanos , Pulmão/enzimologia , Pulmão/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Fibrose Pulmonar/enzimologia , Fibrose Pulmonar/patologia , RNA Interferente Pequeno/genética , Regulação para Cima/efeitos dos fármacosRESUMO
Idiopathic pulmonary fibrosis (IPF) is the most common of the idiopathic interstitial pneumonias. Its signs and symptoms are relatively non-specific, and patients often present with chronic cough, progressive dyspnea, resting or exertional hypoxemia, and inspiratory crackles on lung auscultation. Definitive diagnosis requires the exclusion of known causes of pulmonary fibrosis and identification of the usual interstitial pneumonia (UIP) pattern of disease either on high-resolution computed tomography (HRCT) scan of the chest or on surgical lung biopsy. Multidisciplinary discussion involving pulmonologists, radiologists, and pathologists with expertise in the diagnosis of IPF and other forms of interstitial lung disease is recommended and often required. Management focuses on anti-fibrotic therapy and early referral to lung transplant centers for those who are candidates. This review will discuss the current recommendations for the diagnosis, prognostication, and management of patients with IPF.
Assuntos
Fibrose Pulmonar Idiopática , Doenças Pulmonares Intersticiais , Biópsia , Diagnóstico Diferencial , Humanos , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/terapia , Pulmão/diagnóstico por imagem , Doenças Pulmonares Intersticiais/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
Diagnosis of interstitial lung disease (ILD) requires a multidisciplinary discussion approach that includes clinicians, radiologists, and pathologists. Surgical lung biopsy (SLB) is currently the recommended standard in obtaining pathologic specimens for patients with ILD requiring a tissue diagnosis. The increased diagnostic confidence and accuracy provided by microscopic pathology assessment of SLB specimens must be balanced with the associated risks in patients with ILD. This document was developed by the SLB Working Group of the Pulmonary Fibrosis Foundation, composed of a multidisciplinary group of ILD physicians, including pulmonologists, radiologists, pathologists, and thoracic surgeons. In this document, we present an up-to-date literature review of the indications, contraindications, risks, and alternatives to SLB in the diagnosis of fibrotic ILD; outline an integrated approach to the decision-making around SLB in the diagnosis of fibrotic ILD; and provide practical information to maximize the yield and safety of SLB.
Assuntos
Fibrose Pulmonar Idiopática , Doenças Pulmonares Intersticiais , Fibrose Pulmonar , Biópsia , Broncoscopia , Humanos , Fibrose Pulmonar Idiopática/diagnóstico , Pulmão/diagnóstico por imagem , Doenças Pulmonares Intersticiais/diagnósticoRESUMO
Sphingosine 1-phosphate (S1P) is a key endogenous regulator of the response to lung injury, maintaining endothelial barrier integrity through interaction with one of its receptors, S1P(1). The short-term administration of S1P or S1P(1) receptor agonists enhances endothelial monolayer barrier function in vitro, and attenuates injury-induced vascular leak in the lung and other organ systems in vivo. Although S1P(1) agonists bind to and activate S1P(1), several of these agents also induce receptor internalization and degradation, and may therefore act as functional antagonists of S1P(1) after extended exposure. Here we report on the effects of prolonged exposure to these agents in bleomycin-induced lung injury. We demonstrate that repeated administration of S1P(1) agonists dramatically worsened lung injury after bleomycin challenge, as manifested by increased vascular leak and mortality. Consistent with these results, prolonged exposure to S1P(1) agonists in vitro eliminated the ability of endothelial cell monolayers to respond appropriately to the barrier-protective effects of S1P, indicating a loss of normal S1P-S1P(1) signaling. As bleomycin-induced lung injury progressed, continued exposure to S1P(1) agonists also resulted in increased pulmonary fibrosis. These data indicate that S1P(1) agonists can act as functional antagonists of S1P(1) on endothelial cells in vivo, which should be considered in developing these agents as therapies for vascular leak syndromes. Our findings also support the hypothesis that vascular leak is an important component of the fibrogenic response to lung injury, and suggest that targeting the S1P-S1P(1) pathway may also be an effective therapeutic strategy for fibrotic lung diseases.