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2.
J Allergy Clin Immunol ; 127(2): 439-446.e1-5, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21167578

RESUMO

BACKGROUND: Asthma is characterized by airway inflammation, airway remodeling, and airway hyperresponsiveness (AHR). Myofibroblast differentiation and subepithelial fibrosis are key features of airway remodeling. Extra domain A (EDA)-containing fibronectin (EDA-FN), an alternatively spliced form of the extracellular matrix protein fibronectin, has been implicated in fibroblast differentiation during wound healing and tissue fibrosis. OBJECTIVES: We sought to investigate the role of EDA-FN in airway remodeling using a murine model of chronic allergen-induced experimental asthma. METHODS: EDA(-/-) and wild-type (WT) mice were sensitized and exposed to inhaled ovalbumin (OVA) or saline for 5 weeks. EDA-FN expression was evaluated by means of PCR and immunostaining. Peribronchial fibrosis, smooth muscle area, mucus-producing cell numbers, bronchoalveolar cell counts, and lung function were assessed in WT and EDA(-/-) mice. Fibroblast activation and differentiation were evaluated ex vivo by using OVA-treated WT and EDA(-/-) lung fibroblasts. RESULTS: Exposure to OVA increased EDA-FN expression in lung tissue and primary lung fibroblasts. OVA-treated EDA(-/-) mice showed reduced airway fibrosis and AHR and impaired expression of TGF-ß1 and IL-13 without changes in airway inflammation or other aspects of remodeling. Lung fibroblasts from OVA-treated EDA(-/-) mice exhibited reduced proliferation, migration, α-smooth muscle actin expression, and collagen deposition and impaired TGF-ß1 and IL-13 release compared with that seen in WT mice. CONCLUSIONS: EDA-FN is essential for the development of OVA-induced airway fibrosis and AHR. The effect of the EDA domain on airway fibrosis after OVA challenge is through activation and differentiation of fibroblasts. Fibroblast activation and airway fibrosis are necessary for the development of AHR.


Assuntos
Alérgenos/imunologia , Asma/etiologia , Brônquios/patologia , Hiper-Reatividade Brônquica/etiologia , Fibronectinas/fisiologia , Animais , Fibroblastos/citologia , Fibroblastos/fisiologia , Fibronectinas/química , Fibrose , Interleucina-13/análise , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Terciária de Proteína , Fator de Crescimento Transformador beta1/análise
3.
Exp Lung Res ; 34(8): 467-79, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18850374

RESUMO

Eotaxin-1/CCL11 is important for early eosinophil recruitment to the airways of asthmatics. In order to clarify whether eotaxin-2/CCL24 accounts for prolonged airway eosinophilia, the authors determined the expression of CCL11 and CCL24 in lung tissue and bronchoalveolar lavage (BAL) as well as eosinophil infiltration over 14 days in BALB/c mice sensitised (intraperitonealy) and challenged (inhalations) with ovalbumin (OVA). Allergen exposure induced perivascular, peribronchial, and BAL eosinophilia for up to 7 days. CCL11 and CCL24 were highly expressed in lung tissue from 6 and up to 72 hours. Peak expression of CCL11 protein was 1557 +/- 109 pg/mL for OVA (mean +/- SEM) versus 404 +/- 73 pg/mL in controls (SAL) (P < .001) and 1690 +/- 54 versus 455 +/- 165 pg/mL for CCL24 (P < .01). In BAL, only eotaxin-2/CCL24 was significantly increased (1623 +/- 85 pg/mL for OVA versus 157 +/- 22 pg/mL for SAL, P < .01). Peak eosinophilia and CCL24 expression occurred later in BAL than in lung tissue. These data suggest that both CCL11 and CCL24 are important for recruitment of eosinophils to perivascular and peribronchial tissue seen up to 72 hours. This finding implies redundancy between these chemokines rather than differentially regulated expression over time. In contrast, only CCL24 seems important for recruitment of eosinophils into BAL. Specific inhibition of CCL11 alone is therefore unlikely to inhibit eosinophil recruitment to the airways.


Assuntos
Alérgenos/imunologia , Quimiocina CCL24/metabolismo , Eosinófilos/metabolismo , Ovalbumina/imunologia , Eosinofilia Pulmonar/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/citologia , Quimiocina CCL11/genética , Quimiocina CCL11/metabolismo , Quimiocina CCL24/genética , Feminino , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/metabolismo
4.
J Allergy Clin Immunol ; 117(1): 103-10, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16387592

RESUMO

BACKGROUND: Eotaxin/CCL11 plays an important role in asthma. It acts through the chemokine receptor CCR3 expressed on hematopoietic and nonhematopoietic cells in the lung. OBJECTIVE: To determine whether eotaxin/CCL11 modulates lung and bronchial fibroblast properties and thereby might contribute to airway remodeling. METHODS: CCR3 expression was characterized on a lung fibroblast line (MRC-5; flow cytometry, fluorescent microscopy, RT-PCR, and Northern blotting), on primary bronchial fibroblasts (flow cytometry), and on fibroblasts in human lung tissue (confocal laser microscopy). The effects of eotaxin/CCL11 on lung fibroblast migration (Boyden chamber), proliferation (tritiated thymidine incorporation), alpha-smooth muscle actin expression (ELISA), 3-dimensional collagen gel contraction (floating gel), pro-alpha1(I) collagen mRNA (Northern blotting), total collagen synthesis (tritiated proline incorporation), matrix metalloproteinase activity (gelatin zymography), and TGF-beta(1) release (ELISA) were evaluated. The contribution of eotaxin/CCL11/CCR3 binding on lung fibroblasts was also investigated by neutralizing experiments. RESULTS: CCR3 is constitutively expressed in cultured lung and primary bronchial fibroblasts and colocalizes with specific surface markers for human fibroblasts in lung tissue. Eotaxin/CCL11 selectively modulates fibroblast activities by increasing their proliferation, matrix metalloproteinase 2 activity, and collagen synthesis but not their differentiation into myofibroblasts, contractility in collagen gel, or TGF-beta(1) release. Eotaxin/CCL11 enhances migration of lung fibroblasts in response to nonspecific chemoattractants, and this effect is completely inhibited by anti-CCR3-neutralizing antibodies. CONCLUSION: These data demonstrate that eotaxin/CCL11 has a direct and selective profibrogenic effect on lung and bronchial fibroblasts, providing a novel mechanism whereby eotaxin/CCL11 can participate in airway remodeling in asthma.


Assuntos
Quimiocinas CC/fisiologia , Fibrose Pulmonar/etiologia , Diferenciação Celular , Proliferação de Células , Quimiocina CCL11 , Quimiotaxia , Colágeno/biossíntese , Colágeno/genética , Colágeno Tipo I , Cadeia alfa 1 do Colágeno Tipo I , Feminino , Fibroblastos/patologia , Humanos , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Pessoa de Meia-Idade , Precursores de Proteínas/genética , RNA Mensageiro/análise , Receptores CCR3 , Receptores de Quimiocinas/análise , Receptores de Quimiocinas/genética , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta1
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