RESUMEN
Fibroblast differentiation into myofibroblast in transforming growth factor-beta1-exposed human lung fibroblasts and the immunolocalizations of alpha-smooth muscle actin, fibronectin, tenascin-C, and osteopontin in exposed cells were studied by conventional transmission electron microscopy and immunoelectron microscopy. Ultrastructural features of myofibroblasts were detected after exposure, e.g., alpha-smooth muscle actin positive bundles in the cytoplasm of cells and extracellular fibronectin-containing structures on the surface of the cell forming fibronexus structure, osteopontin adjacent to rough endoplastic reticulum and extracellular tenascin-C in the vicinity of the cell. The authors concluded that exposure to transforming growth factor-beta1 can differentiate lung fibroblasts into ultrastructurally typical myofibroblasts.
Asunto(s)
Diferenciación Celular/fisiología , Fibroblastos/citología , Pulmón/citología , Actinas/biosíntesis , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibronectinas/biosíntesis , Humanos , Inmunohistoquímica , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Enfermedades Pulmonares/patología , Microscopía Electrónica de Transmisión , Microscopía Inmunoelectrónica , Músculo Liso/citología , Músculo Liso/metabolismo , Osteopontina/biosíntesis , Tenascina/biosíntesis , Factor de Crecimiento Transformador beta1/farmacologíaRESUMEN
The aim of this study was to study the expression of various claudins in sarcoidosis, usual interstitial pneumonia (UIP), and normal human lung. The expression and cell-specific localization of claudin-1, -2, -3, -4, -5, and -7 was analyzed by IHC. Bronchiolar epithelial cells showed mostly strong expression for claudin-1, -2, -3, -4, and -7 and mainly weak expression for claudin-5 in UIP, sarcoidosis, and normal lung. Three claudins, claudin-3, -4, and -7, were expressed in normal alveolar epithelium, mainly in type II pneumocytes. Claudin-5 was expressed strongly in endothelium of normal lung, and its staining was extremely intense in endothelium of UIP. Moderate or strong expression for claudin-1, -2, -3, -4, and -7 was observed in metaplastic alveolar- and bronchiolar-type epithelium in UIP and also in metaplastic alveolar-type epithelium in sarcoidosis. Expression of claudin-5 was mainly weak in metaplastic alveolar- and bronchiolar-type epithelium in UIP. We conclude that claudin-1, -2, -3, -4, -5, and -7 are expressed in UIP and sarcoidosis, and furthermore, the most prominent enhancement of staining is localized in metaplastic alveolar- and bronchiolar-type epithelium in UIP compared with the healthy lung.
Asunto(s)
Enfermedades Pulmonares Intersticiales/metabolismo , Proteínas de la Membrana/biosíntesis , Sarcoidosis Pulmonar/metabolismo , Claudina-1 , Claudina-3 , Claudina-4 , Claudina-5 , Claudinas , Humanos , Inmunohistoquímica , Pulmón/metabolismo , Mucosa Respiratoria/metabolismoRESUMEN
The thioredoxin/peroxiredoxin system comprises a redox-regulated antioxidant family in human lung; its significance, regulation, or oxidation has not been evaluated in smoking-related lung diseases. Here, we present the expression of the thioredoxin/peroxiredoxin system in lung biopsies from normal lung (n = 14), smokers (n = 21), and patients with chronic obstructive pulmonary disease (COPD, n = 38), and assess the possible inactivation/oxidation of this system by nonreducing Western blotting, two-dimensional gel electrophoresis, and mass spectrometry. Our study shows that the thiol status of the Trx/Prx-system can be modulated in vitro, but it appears to have high resistance against the oxidative stress in COPD.
Asunto(s)
Estrés Oxidativo , Peroxirredoxinas/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Tiorredoxinas/metabolismo , Electroforesis en Gel Bidimensional , Humanos , Oxidación-Reducción , Enfermedad Pulmonar Obstructiva Crónica/patologíaRESUMEN
Sarcoidosis, atypical mycobacteriosis, and tuberculosis are common diseases of human lung with a typical feature of formation of granulomas. The structure of granulomas has not been elucidated completely. We studied the expression of tenascin-C, precursor proteins of collagens I and III, and the presence of myofibroblasts in granulomas of sarcoidosis, atypical mycobacteriosis, and tuberculosis of human lung. Twenty-five histologic samples of lung were analyzed by immunohistochemistry using antibodies to tenascin-C and aminoterminal propeptides of collagens I and III. To identify the myofibroblast-type cells in granulomas, the sections were also stained with antibodies against alpha-smooth muscle actin, vimentin, and desmin. In every case, tenascin-C and precursor proteins of collagens I and III were expressed around granulomas. Precursor protein of collagen I was expressed also within them. In tuberculosis and atypical mycobacteriosis, expression of tenascin-C and precursor protein of collagen I was stronger than in sarcoidosis. The cells demarcating granulomas and, thus, colocalizing with tenascin-C and both collagen precursors were positive for alpha-smooth muscle actin and vimentin, which suggests that these cells are myofibroblasts. They were also more abundantly present in tuberculosis and atypical mycobacteriosis, as suggested by alpha-smooth muscle actin staining. We concluded that tenascin-C and precursor proteins of collagens I and III are expressed around granulomas in sarcoidosis, atypical mycobacteriosis, and tuberculosis of the lung; and furthermore, their expression colocalize with the expression of myofibroblasts. Our results further point to the fact that fibrogenesis and matrix turnover is stronger in tuberculosis and atypical mycobacteriosis than in sarcoidosis.
Asunto(s)
Proteínas de la Matriz Extracelular/análisis , Fibroblastos/patología , Granuloma/patología , Infecciones por Mycobacterium no Tuberculosas/patología , Sarcoidosis Pulmonar/patología , Tuberculosis Pulmonar/patología , Actinas/análisis , Biomarcadores/análisis , Femenino , Fibroblastos/química , Granuloma/metabolismo , Humanos , Inmunohistoquímica , Pulmón/química , Pulmón/patología , Masculino , Músculo Liso/química , Músculo Liso/patología , Infecciones por Mycobacterium no Tuberculosas/metabolismo , Fragmentos de Péptidos/análisis , Procolágeno/análisis , Sarcoidosis Pulmonar/metabolismo , Tenascina/análisis , Tuberculosis Pulmonar/metabolismoRESUMEN
Idiopathic usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) and asbestosis represent progressive and often fatal pulmonary fibrous disorders, whereas cryptogenic organizing pneumonia (COP), desquamative interstitial pneumonia (DIP), and respiratory bronchiolitis-interstitial lung disease (RB-ILD) usually are reversible or nonprogressive conditions. Prostaglandin E2 (PGE2) inhibits fibroblast proliferation and myofibroblast transition, its production depending on cyclooxygenase-2 (COX-2). In patients with UIP/IPF, levels of PGE2 and COX-2 are reduced in fibroblasts, and levels of PGE2 in bronchioalveolar lavage fluid may be lowered. We analyzed the immunohistochemical expression of COX-2 in UIP/IPF, asbestosis, COP, DIP, and RB-ILD. Our results show that the metaplastic epithelium in UIP/IPF, asbestosis, and COP is widely COX-2+, whereas COX-2 positivity is scant in DIP and RB-ILD. The mesenchymal cells remained negative. Our results suggest that irrespective of the underlying disease, lung injury that causes extensive fibrosis induces wide expression of COX-2 in the regenerating metaplastic epithelium.
Asunto(s)
Ciclooxigenasa 2/metabolismo , Proteínas de la Membrana/metabolismo , Fibrosis Pulmonar/patología , Asbestosis/enzimología , Asbestosis/patología , Bronquiolitis/enzimología , Bronquiolitis/patología , Neumonía en Organización Criptogénica/enzimología , Neumonía en Organización Criptogénica/patología , Epitelio/enzimología , Epitelio/patología , Humanos , Inmunohistoquímica , Enfermedades Pulmonares Intersticiales/enzimología , Enfermedades Pulmonares Intersticiales/patología , Metaplasia , Fibrosis Pulmonar/enzimologíaRESUMEN
OBJECTIVES: To evaluate the effect of lung biopsy on the survival of patients when histopathologic confirmation of usual interstitial pneumonia (UIP) is needed. BACKGROUND: Idiopathic pulmonary fibrosis is a distinct clinical entity with histopathologic features of UIP. Surgical biopsy is needed when clinical and radiologic findings are not typical. The safety of lung biopsy is a matter of debate, and the results of short-term mortality (< 30 days) after biopsy are variable. METHODS: Seventy-six patients with UIP, including 34 patients who underwent video-assisted thoracoscopic surgery (VATS) biopsy and 42 patients who underwent open-lung biopsy, were included in this retrospective study. All biopsies were reevaluated for UIP histopathology. Clinical data such as age at the time of biopsy, type of biopsy, preoperative pulmonary function, major postoperative complications, date and cause of death, and survival time after the biopsy were gathered. Median survival was used to compare the survival between different groups, and cumulative survival was estimated using Kaplan-Meyer method. RESULTS: Thoracoscopic biopsy was safe for diagnosing UIP, with no short-term mortality. In contrast, open-lung biopsy was followed by four deaths (5.3%) within 1 month after the procedure. All fatal cases were accompanied by a histopathologic pattern of diffuse alveolar damage. Age of the patient at the time of biopsy was a significant predicting factor for survival. Patients < 50 years old lived 181 months (range, 119 to 242 months), and patients > 50 years old lived 75 months (range, 55 to 95 months). CONCLUSIONS: VATS biopsy is a safe procedure in diagnosing UIP.
Asunto(s)
Enfermedades Pulmonares Intersticiales/diagnóstico , Pulmón/patología , Toracoscopía/métodos , Biopsia/métodos , Femenino , Humanos , Enfermedades Pulmonares Intersticiales/mortalidad , Enfermedades Pulmonares Intersticiales/patología , Masculino , Persona de Mediana Edad , Fibrosis Pulmonar/patología , Reproducibilidad de los Resultados , Seguridad , Fumar , Análisis de SupervivenciaRESUMEN
Lysyl oxidases, a family comprising LOX and four LOX-like enzymes, catalyze crosslinking of elastin and collagens. Mouse Lox was recently shown to be crucial for development of the cardiovascular system because null mice died perinatally of aortic aneurysms and cardiovascular dysfunction. We show here that Lox is also essential for development of the respiratory system and the integrity of elastic and collagen fibers in the lungs and skin. The lungs of E18.5 Lox(-/-) embryos showed impaired development of the distal and proximal airways. Elastic fibers in E18.5 Lox(-/-) lungs were markedly less intensely stained and more disperse than in the wild type, especially in the mesenchyme surrounding the distal airways, bronchioles, bronchi, and trachea, and were fragmented in pulmonary arterial walls. The organization of individual collagen fibers into tight bundles was likewise abnormal. Similar elastic and collagen fiber abnormalities were seen in the skin. Lysyl oxidase activity in cultured Lox(-/-) skin fibroblasts and aortic smooth muscle cells was reduced by approximately 80%, indicating that Lox is the main isoenzyme in these cells. LOX abnormalities may thus be critical for the pathogenesis of several common diseases, including pulmonary, skin, and cardiovascular disorders.
Asunto(s)
Colágeno/metabolismo , Elastina/metabolismo , Proteína-Lisina 6-Oxidasa/fisiología , Sistema Respiratorio/crecimiento & desarrollo , Sistema Respiratorio/metabolismo , Animales , Aorta/citología , Aorta/embriología , Células Cultivadas , Colágeno/ultraestructura , Colágeno Tipo I/metabolismo , Colágeno Tipo I/ultraestructura , Colágeno Tipo IV/metabolismo , Colágeno Tipo IV/ultraestructura , Medios de Cultivo Condicionados/análisis , Elastina/ultraestructura , Desarrollo Embrionario , Fibroblastos/citología , Fibroblastos/enzimología , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Técnica del Anticuerpo Fluorescente Indirecta , Colorantes Fluorescentes , Heterocigoto , Homocigoto , Inmunohistoquímica , Pulmón/embriología , Pulmón/enzimología , Pulmón/crecimiento & desarrollo , Pulmón/metabolismo , Pulmón/ultraestructura , Ratones , Ratones Noqueados , Microscopía Fluorescente , Microscopía Inmunoelectrónica , Músculo Liso Vascular/citología , Músculo Liso Vascular/embriología , Músculo Liso Vascular/enzimología , Músculo Liso Vascular/metabolismo , Proteína-Lisina 6-Oxidasa/análisis , Proteína-Lisina 6-Oxidasa/genética , Sistema Respiratorio/embriología , Sistema Respiratorio/enzimología , Sistema Respiratorio/ultraestructura , Rodaminas , Piel/citología , Piel/embriología , Piel/enzimología , Piel/crecimiento & desarrollo , Piel/metabolismo , Piel/ultraestructuraRESUMEN
The aim of this study was to assess and compare the accumulation and distribution of newly synthesized type I and III collagens in usual interstitial pneumonia (UIP) and pulmonary sarcoidosis. Lung biopsies from 10 patients with UIP and 13 patients with sarcoidosis were investigated by immunohistochemical technique and mRNA in situ hybridization. The antibodies for the aminoterminal propeptide of type I procollagen and the aminoterminal propeptide of type III procollagen (PINP and PIIINP, respectively) were used. When compared to healthy lung, levels of type I pN- and type III pN-collagens were increased in both of these disorders. Type I procollagen was mostly present as intracellular spots in newly formed fibrosis in UIP while type III pN-collagen was expressed extracellularly underneath metaplastic alveolar epithelium. Type I procollagen was present intracellularly within and around the granulomas of sarcoidosis, whereas type III pN-collagen was expressed extracellularly, mainly around the granulomas. mRNAs of both collagens colocalized with the precursor proteins. We conclude that the expression of precursor proteins and mRNA of type I and type III collagens is increased in UIP and sarcoidosis, reflecting mainly active synthesis of these collagens in different areas of the lung.
Asunto(s)
Colágeno Tipo III/genética , Colágeno Tipo III/metabolismo , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Enfermedades Pulmonares Intersticiales/metabolismo , Precursores de Proteínas/metabolismo , Sarcoidosis/metabolismo , Humanos , Inmunohistoquímica , Hibridación in Situ , Enfermedades Pulmonares Intersticiales/genética , Transporte de Proteínas , Alveolos Pulmonares , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sarcoidosis/genéticaRESUMEN
Glutaredoxins (Grx) are thiol-disulfide oxidoreductases with antioxidant capacity and catalytic functions closely associated with glutathione, an antioxidant abundantly present in human lung. The present study investigated the expression of both human glutaredoxins in cultured human lung cells and lung homogenates by reverse-transcription polymerase chain reaction and Western blotting. Immunohistochemical studies were conducted with 38 human lung specimens, including healthy lung, parenchymal sarcoidosis, extrinsic allergic alveolitis, and usual interstitial pneumonia (UIP). The ultrastructural localization of Grx1 was assessed by immunoelectron microscopy. In addition, cultured airway epithelial cells were exposed to tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta. Both Grx1 and Grx2 could be detected at the mRNA and protein level in cultured human lung cells, but only Grx1 was prominently expressed in lung homogenates and alveolar macrophages. Immunohistochemically, Grx1 was highly concentrated to alveolar macrophages and weakly positive in the bronchial epithelium. Grx1 was ultrastructurally localized to the plasma membrane, cytoplasmic vacuoles, and nucleus. The expression of Grx1 decreased in alveolar macrophages of sarcoidosis and allergic alveolitis compared with the case for controls (P < 0.001), and bronchial epithelium of these diseases revealed no Grx1 immunoreactivity. Fibroblast foci and other fibrotic areas in UIP were mainly negative. In A549 cells, Grx1 was down-regulated by TGF-beta, whereas TNF-alpha caused no clear effect. Overall, high expression of Grx1 in alveolar macrophages suggests its importance in the primary defense of human lung. Decreased expression of Grx1 further suggests the impairment of this system both in inflammatory and fibrotic lung diseases, consistent with the down-regulation of Grx1 by TGF-beta in vitro.
Asunto(s)
Enfermedades Pulmonares Intersticiales/metabolismo , Pulmón/metabolismo , Oxidorreductasas/biosíntesis , Factor de Crecimiento Transformador beta/farmacología , Western Blotting , Línea Celular Transformada , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Glutarredoxinas , Humanos , Pulmón/efectos de los fármacos , Pulmón/patología , Enfermedades Pulmonares Intersticiales/patología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/ultraestructura , Masculino , Microscopía Inmunoelectrónica , Persona de Mediana Edad , Oxidorreductasas/genética , ARN Mensajero/metabolismo , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
We studied cell-specific protein expression of all the major antioxidant enzymes (AOEs) and related proteins, such as copper-zinc superoxide dismutase (CuZnSOD), manganese SOD (MnSOD), extracellular SOD (ECSOD), catalase, the heavy and light chains of gamma-glutamylcysteine synthetase (gamma-GCS-l and gamma-GCS-h, also called glutamate cysteine ligase), the rate-limiting enzyme in glutathione synthesis, hemeoxygenase-1 (HO-1), and thioredoxin (Trx), in developing human lung, respiratory distress syndrome, and bronchopulmonary dysplasia by immunohistochemistry. Generally, after 17 weeks of gestational age, MnSOD was predominantly expressed in bronchial epithelium, alveolar epithelium, and macrophages, CuZnSOD was expressed in bronchial epithelium, ECSOD was expressed in bronchial epithelium, vascular endothelium, and the extracellular matrix, catalase was expressed in bronchial epithelium and alveolar macrophages, gamma-GCS-h was expressed in bronchial epithelium and endothelium, and gamma-GCS-l was expressed in bronchial epithelium. Trx was restricted to bronchial epithelium and to a lesser extent to alveolar macrophages, and HO-1 found in alveolar macrophages. Basically, the expression of these enzymes was similar in normal and diseased lung. It can be concluded that various AOEs and related proteins differ in their distribution and expression in lung before term, but generally it seems that infants are better adapted to high oxygen tension than might be expected.
Asunto(s)
Antioxidantes/metabolismo , Displasia Broncopulmonar/embriología , Displasia Broncopulmonar/enzimología , Pulmón/embriología , Pulmón/enzimología , Síndrome de Dificultad Respiratoria del Recién Nacido/embriología , Síndrome de Dificultad Respiratoria del Recién Nacido/enzimología , Displasia Broncopulmonar/patología , Catalasa/metabolismo , Femenino , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Glutamato-Cisteína Ligasa/metabolismo , Hemo Oxigenasa (Desciclizante)/metabolismo , Hemo-Oxigenasa 1 , Humanos , Lactante , Recién Nacido , Pulmón/patología , Masculino , Proteínas de la Membrana , Embarazo , Resultado del Embarazo , Síndrome de Dificultad Respiratoria del Recién Nacido/patología , Superóxido Dismutasa/metabolismo , Tiorredoxinas/metabolismoRESUMEN
The pathogenesis of interstitial lung diseases (ILDs) is known to be associated with reactive oxygen and nitrogen metabolites and increased oxidant stress. One of the major antioxidants in human lung is glutathione (GSH) and enzymes linked to its synthesis. The rate-limiting enzyme of GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS) containing catalytically active heavy (gamma-GCSh) and regulatory light (gamma-GCSl) subunits. It can be hypothesized that gamma-GCS is the major determinant in explaining reduced GSH levels in fibrotic lung disorders. We investigated the regulation of gamma-GCS by transforming growth factor beta(1) (TGF-beta(1)) and tumor necrosis factor alpha (TNF-alpha) in human lung cells and its expression and distribution in fibrotic (biopsy-proven idiopathic pulmonary fibrosis, for instance, usual interstitial pneumonia, UIP, n = 15), inflammatory, and granulomatous diseases of human lung parenchyma (desquamative interstitial pneumonia, n = 10; ILD associated with collagen diseases, n = 10; sarcoidosis, n = 19 and allergic alveolitis, n = 8). In human lung alveolar epithelial cells, gamma-GCSh was decreased by TGF-beta(1), whereas TNF-alpha caused a transient enzyme induction. In normal lung, gamma-GCS was mainly localized to the bronchiolar epithelium. In UIP, the highest immunoreactivities were observed in the airway epithelium and metaplastic alveolar epithelium, but fibroblastic foci were negative. In sarcoidosis, the highest reactivities were detected in the epithelium, alveolar macrophages and pulmonary granulomas. gamma-GCS was ultrastructurally localized to the cytoplasm of regenerating type II pneumocytes and macrophages. In conclusion, gamma-GCS is widely expressed in sarcoidosis and regenerating epithelium but is low in the fibrotic areas of usual interstitial pneumonia, probably because of enzyme down-regulation.
Asunto(s)
Glutamato-Cisteína Ligasa/metabolismo , Enfermedades Pulmonares Intersticiales/enzimología , Alveolos Pulmonares/enzimología , Mucosa Respiratoria/enzimología , Adulto , Anciano , Western Blotting , Línea Celular , Femenino , Humanos , Inmunohistoquímica , Enfermedades Pulmonares Intersticiales/patología , Enfermedades Pulmonares Intersticiales/fisiopatología , Masculino , Microscopía Inmunoelectrónica , Persona de Mediana Edad , Alveolos Pulmonares/patología , Pruebas de Función Respiratoria , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/ultraestructura , Factor de Crecimiento Transformador beta/farmacología , Factor de Crecimiento Transformador beta1 , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
BACKGROUND: Tenascin-C (Tn-C) is the most studied member of a family comprising large oligomeric glycoproteins in the extracellular matrix. The function of Tn-C still is unclear, and the levels of Tn-C in human wound fluid have not been studied. METHODS: The participants in this study were 24 patients referred for elective major gastrointestinal surgery. Concentrations of Tn-C and procollagen propeptides type 1 and type 3 in serum and wound fluid were measured after surgery. RESULTS: In wound fluid, Tn-C was present on postoperative day 1, and the concentration increased from day 5 up to day 7. CONCLUSIONS: The concentration of Tn-C increases postoperatively in wound fluid. The concentration of Tn-C in wound fluid is markedly higher than that of serum. The differences in expression between Tn-C and the procollagen propeptides may reflect different tasks of these extracellular matrix proteins.
Asunto(s)
Fragmentos de Péptidos/sangre , Procolágeno/sangre , Infección de la Herida Quirúrgica/metabolismo , Tenascina/sangre , Cicatrización de Heridas/fisiología , Femenino , Enfermedades Gastrointestinales/cirugía , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/aislamiento & purificación , Procolágeno/aislamiento & purificación , Tenascina/aislamiento & purificación , Tenascina/fisiologíaRESUMEN
Extracellular matrix proteins have a prominent role in both ontogenesis and fibrogenesis in the human lung. The aim of this study was to analyse the expression of newly formed precursor proteins and mRNA of collagen types I and III in developing human lung tissues from 12 to 40 weeks of gestation, and also in neonatal disorders such as respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD). Lung tissues were obtained at autopsy from 60 non-malformed cases. All tissues were analysed by immunohistochemistry and 24 were also investigated by mRNA in situ hybridization. The precursor proteins and mRNA of both collagens were expressed in abundance in pulmonary arteries and veins during all developmental periods. In RDS and BPD, precursor proteins and mRNAs of both collagen types were increased within alveolar walls. The cells in these locations showed alpha-smooth muscle actin, vimentin, and variable desmin immunoreactivity. Collagen I and III precursor proteins and mRNA were also observed in pleura, bronchi, bronchioles, and around chondrocytes during all developmental periods and in diseased lung. In conclusion, collagens I and III were expressed in a similar way in and around various cell types in the developing lung and their expression was increased within alveolar walls in RDS and BPD. Myofibroblast-type cells appeared to produce mRNA for both types of collagen in alveoli.
Asunto(s)
Colágeno Tipo III/análisis , Colágeno Tipo I/análisis , Pulmón/embriología , Precursores de Proteínas/análisis , ARN Mensajero/análisis , Actinas/análisis , Displasia Broncopulmonar/metabolismo , Desmina/análisis , Epitelio/metabolismo , Edad Gestacional , Humanos , Inmunohistoquímica/métodos , Hibridación in Situ/métodos , Recién Nacido , Pulmón/metabolismo , Alveolos Pulmonares/metabolismo , Arteria Pulmonar/metabolismo , Venas Pulmonares/metabolismo , Síndrome de Dificultad Respiratoria del Recién Nacido/metabolismo , Vimentina/análisisRESUMEN
Insufficient reepithelialization of injured alveolar walls may be important in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Laminin-5 is expressed in epithelial cells of healing wounds, promoting cell attachment and migration. In this study we have studied the extent of reepithelialization of newly formed intraluminal connective tissue, the immunohistochemical expression and ultrastructural localization of the laminin-5 gamma2 chain protein, and the synthesis of the laminin-5 gamma2 chain mRNA in regenerating epithelial cells in cryptogenic organizing pneumonia (COP) and IPF. The results show that the mean extent of reepithelialization of intraluminal connective tissue lesions was 76% (SD, +/- 27%) in COP, and 54% (SD, +/- 23%) in IPF (p < 0.025). The laminin-5 gamma2 chain was synthesized and widely expressed in regenerating epithelial cells in both diseases. Immunohistochemistry for surfactant-associated protein A suggests a pneumocyte origin for the regenerating epithelial cells in IPF. It is concluded that both in COP and IPF, regenerating epithelial cells are capable of synthesizing the laminin-5 gamma2 chain needed for adhesive connections to the underlying basement membrane. However, in IPF, the reepithelialization seems to be disturbed or delayed.
Asunto(s)
Neumonía en Organización Criptogénica/patología , Laminina/metabolismo , Fibrosis Pulmonar/patología , Regeneración/fisiología , Membrana Basal/fisiología , Biopsia con Aguja , Técnicas de Cultivo , Femenino , Humanos , Inmunohistoquímica , Laminina/análisis , Masculino , Microscopía Electrónica , Pronóstico , Mucosa Respiratoria/patología , Mucosa Respiratoria/ultraestructura , Sensibilidad y EspecificidadRESUMEN
The thioredoxin system containing thioredoxin (Trx) and thioredoxin reductase (TrxR) has profound effects on cell proliferation and protection against exogenous oxidants. The significance of the Trx system in human lung and lung diseases is, however, largely unresolved. Altogether, 66 specimens of human lung were investigated by immunohistochemistry for their expression of Trx and TrxR. The diseases included interstitial pneumonias such as usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), and UIP associated with collagen vascular diseases (CVD-ILD), and granulomatous diseases such as sarcoidosis and allergic alveolitis. The ultrastructural localization of Trx and TrxR was analysed by immunoelectron microscopy. In healthy lung, Trx and TrxR were expressed in bronchial epithelium and alveolar macrophages. Trx and TrxR were highly concentrated in areas of metaplastic epithelium in UIP and in alveolar macrophages in DIP, though fibrotic areas in UIP were mainly negative. The expression of both enzymes was clearly weaker in CVD-ILD than in UIP. Granulomas of sarcoidosis showed moderate to intense Trx immunoreactivity. Ultrastructurally, Trx and TrxR were expressed diffusely in the cytosolic compartment and plasma membrane of metaplastic type II pneumocytes, macrophages, and bronchial epithelial cells. This study highlights the importance of Trx and TrxR in primary defence in bronchial epithelium, alveolar epithelium, and macrophages in human lung, but also indicates that elevated expression of these proteins may serve as markers of ongoing cell regeneration and inflammation.
Asunto(s)
Enfermedades Pulmonares Intersticiales/metabolismo , Tiorredoxinas/análisis , Alveolitis Alérgica Extrínseca/patología , Bronquios/patología , Líquido del Lavado Bronquioalveolar , Membrana Celular/patología , Colágeno/análisis , Citosol/patología , Epitelio/patología , Humanos , Inmunohistoquímica/métodos , Pulmón/patología , Microscopía Inmunoelectrónica/métodos , Sarcoidosis Pulmonar/patología , Reductasa de Tiorredoxina-Disulfuro/análisis , Enfermedades Vasculares/patologíaRESUMEN
Glutathione (GSH) plays a major role in protecting the airways against oxidative stress. The rate-limiting enzyme in de novo GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS), which is induced by acute exposure to GSH-depleting cytokines and oxidants, but downregulated by transforming growth factor beta and prolonged oxidant exposure, at least in vitro. Cell-specific expression or regulation of gamma-GCS may play an important role both in the defense against oxidants and in the pathogenesis of oxidant-associated airway diseases. In this study, the localizations of gamma-GCS heavy (gamma-GCS-HS) and light (gamma-GCS-LS) subunits were investigated by immunohistochemistry in 22 patients with chronic obstructive pulmonary disease (COPD), 20 smokers without COPD, and 13 lifelong nonsmokers. The ultrastructural distributions of both gamma-GCS subunits were assessed by immuno-electron microscopy. Both subunits were expressed most prominently in the large airways, and their ultrastructural localization was both cytoplasmic and along the plasma membrane. The expression of gamma-GCS-HS was stronger in the central bronchial epithelium than in the peripheral bronchioli (p = 0.020), or in alveolar macrophages (p = 0.008). The expression of gamma-GCS-HS in the central bronchial epithelium showed a tendency to be higher in nonsmokers compared with all smokers (p = 0.052). Alveolar macrophages of nonsmokers had higher levels of gamma-GCS-HS (p = 0.001) and gamma-GCS-LS (p = 0.001) than did smokers. The expression of gamma-GCS-HS in the central bronchial epithelium was more marked in nonsmokers than in patients with COPD (p = 0.015), the difference between smokers and patients with COPD was not significant. In conclusion, the heavy and light subunits of gamma-GCS are mainly expressed in the large airways. Their tendency to decrease in cigarette smokers may further predispose lung cells to ongoing oxidant stress, which contributes to the progression of lung injury.
Asunto(s)
Glutamato-Cisteína Ligasa/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/enzimología , Enfermedad Pulmonar Obstructiva Crónica/patología , Fumar/inmunología , Anciano , Análisis de Varianza , Biopsia con Aguja , Estudios de Casos y Controles , Técnicas de Cultivo , Femenino , Glutamato-Cisteína Ligasa/análisis , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Probabilidad , Enfermedad Pulmonar Obstructiva Crónica/etiología , Valores de Referencia , Sensibilidad y Especificidad , Fumar/efectos adversosRESUMEN
Tenascin-C is an extracellular matrix (ECM) glycoprotein expressed in human tissues during organogenesis and in fibrotic and neoplastic processes. We hypothesized that its expression would increase in human lung in neonatal disorders such as infant respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD). Tenascin-C expression was studied by immunohistochemistry (IHC) and mRNA in situ hybridization (ISH). The extent of tenascin-C immunoreactivity was scored as absent (0), low (+), moderate (++), strong (+++), or very strong (++++) separately in different types of pulmonary cells in controls (seven cases), RDS (19 cases), and BPD (12 cases). In controls, tenascin-C expression was low (+) underneath alveolar and bronchiolar epithelium, moderate (++) in intima of veins, and strong (+++) around chondrocytes. In RDS, tenascin-C expression was moderate (++) or strong (+++) underneath both bronchiolar and often detached alveolar epithelium underlying hyaline membranes in the walls of dilated alveoli. In particular, the patients with RDS who survived for 1 day or more had strong expression of tenascin-C within alveolar walls. In patients with BPD, tenascin-C was very strongly (++++) expressed in the remodeled fibrotic alveolar walls underneath regenerative epithelium. Increased expression of tenascin-C mRNA was seen below the alveolar and bronchiolar epithelia in RDS and BPD. The cells in these locations showed alpha-smooth muscle actin immunoreactivity, suggesting a myofibroblast phenotype. In conclusion, tenascin-C is highly expressed in the walls of alveoli and bronchioli in RDS and BPD, suggesting an association between the expression of this protein and the presence of these disorders.