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1.
J Physiol ; 596(8): 1397-1417, 2018 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-29380370

RESUMEN

KEY POINTS: The mechanisms by which bacteria alter endothelial cell phenotypes and programme inflammatory angiogenesis remain unclear. In lung endothelial cells, we demonstrate that toll-like receptor 4 (TLR4) signalling induces activation of forkhead box protein C2 (FOXC2), a transcriptional factor implicated in lymphangiogenesis and endothelial specification, in an extracellular signal-regulated kinase (ERK)-dependent manner. TLR4-ERK-FOXC2 signalling regulates expression of the Notch ligand DLL4 and signals inflammatory angiogenesis in vivo and in vitro. Our work reveals a novel link between endothelial immune signalling (TLR pathway) and a vascular transcription factor, FOXC2, that regulates embryonic vascular development. This mechanism is likely to be relevant to pathological angiogenesis complicating inflammatory diseases in humans. ABSTRACT: Endothelial cells (ECs) mediate a specific and robust immune response to bacteria in sepsis through the activation of toll-like receptor (TLR) signalling. The mechanisms by which bacterial ligands released during sepsis programme EC specification and altered angiogenesis remain unclear. We postulated that the forkhead box protein C2 (FOXC2) transcriptional factor directs EC cell-fate decisions and angiogenesis during TLR signalling. In human lung ECs, lipopolysaccharide (LPS) induced ERK phosphorylation, FOXC2, and delta-like 4 (DLL4, the master regulator of sprouting angiogenesis expression) in a TLR4-dependent manner. LPS-mediated ERK phosphorylation resulted in FOXC2-ERK protein ligation, ERK-dependent FOXC2 serine and threonine phosphorylation, and subsequent activation of DLL4 gene expression. Chemical inhibition of ERK or ERK-2 dominant negative transfection disrupted LPS-mediated FOXC2 phosphorylation and transcriptional activation of FOXC2. FOXC2-siRNA or ERK-inhibition attenuated LPS-induced DLL4 expression and angiogenic sprouting in vitro. In vivo, intraperitoneal LPS induced ERK and FOXC2 phosphorylation, FOXC2 binding to DLL4 promoter, and FOXC2/DLL4 expression in the lung. ERK-inhibition suppressed LPS-induced FOXC2 phosphorylation, FOXC2-DLL4 promoter binding, and induction of FOXC2 and DLL4 in mouse lung ECs. LPS induced aberrant retinal angiogenesis and DLL4 expression in neonatal mice, which was attenuated with ERK inhibition. FOXC2+/- mice treated with LPS showed a mitigated increase in FOXC2 and DLL4 compared to FOXC2+/+ mice. These data reveal a new mechanism (TLR4-ERK-FOXC2-DLL4) by which sepsis-induced EC TLR signalling programmes EC specification and altered angiogenesis.


Asunto(s)
Células Endoteliales/inmunología , Factores de Transcripción Forkhead/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de la Membrana/metabolismo , Neovascularización Fisiológica , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas de Unión al Calcio , Diferenciación Celular , Células Cultivadas , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Lipopolisacáridos/toxicidad , Pulmón/irrigación sanguínea , Pulmón/embriología , Pulmón/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo
2.
Am J Respir Crit Care Med ; 189(3): 301-13, 2014 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-24392884

RESUMEN

RATIONALE: Goblet cell metaplasia accompanies common pulmonary disorders that are prone to recurrent viral infections. Mechanisms regulating both goblet cell metaplasia and susceptibility to viral infection associated with chronic lung diseases are incompletely understood. OBJECTIVES: We sought to identify the role of the transcription factor FOXA3 in regulation of goblet cell metaplasia and pulmonary innate immunity. METHODS: FOXA3 was identified in airways from patients with asthma and chronic obstructive pulmonary disease. We produced transgenic mice conditionally expressing Foxa3 in airway epithelial cells and developed human bronchial epithelial cells expressing Foxa3. Foxa3-regulated genes were identified by immunostaining, Western blotting, and RNA analysis. Direct binding of FOXA3 to target genes was identified by chromatin immunoprecipitation sequencing correlated with RNA sequencing. MEASUREMENTS AND MAIN RESULTS: FOXA3 was highly expressed in airway goblet cells from patients with asthma and chronic obstructive pulmonary disease. FOXA3 was induced by either IL-13 or rhinovirus. Foxa3 induced goblet cell metaplasia and enhanced expression of a network of genes mediating mucus production. Paradoxically, FOXA3 inhibited rhinovirus-induced IFN production, IRF-3 phosphorylation, and IKKε expression and inhibited viral clearance and expression of genes required for antiviral defenses, including MDA5, RIG-I, TLR3, IRF7/9, and nuclear factor-κB. CONCLUSIONS: FOXA3 induces goblet cell metaplasia in response to infection or Th2 stimulation. Suppression of IFN signaling by FOXA3 provides a plausible mechanism that may serve to limit ongoing Th1 inflammation during the resolution of acute viral infection; however, inhibition of innate immunity by FOXA3 may contribute to susceptibility to viral infections associated with chronic lung disorders accompanied by chronic goblet cell metaplasia.


Asunto(s)
Asma/metabolismo , Células Caliciformes/patología , Factor Nuclear 3-gamma del Hepatocito/metabolismo , Inmunidad Innata/fisiología , Infecciones por Picornaviridae/inmunología , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Animales , Asma/complicaciones , Asma/inmunología , Asma/patología , Biomarcadores/metabolismo , Western Blotting , Inmunoprecipitación de Cromatina , Susceptibilidad a Enfermedades , Células Caliciformes/inmunología , Células Caliciformes/metabolismo , Factor Nuclear 3-gamma del Hepatocito/inmunología , Humanos , Interferones/metabolismo , Metaplasia , Ratones , Ratones Transgénicos , Infecciones por Picornaviridae/etiología , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/inmunología , Enfermedad Pulmonar Obstructiva Crónica/patología , Rhinovirus , Análisis de Secuencia de ARN , Balance Th1 - Th2
3.
Proc Natl Acad Sci U S A ; 109(41): 16630-5, 2012 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-23012424

RESUMEN

Airway mucus plays a critical role in clearing inhaled toxins, particles, and pathogens. Diverse toxic, inflammatory, and infectious insults induce airway mucus secretion and goblet cell metaplasia to preserve airway sterility and homeostasis. However, goblet cell metaplasia, mucus hypersecretion, and airway obstruction are integral features of inflammatory lung diseases, including asthma, chronic obstructive lung disease, and cystic fibrosis, which cause an immense burden of morbidity and mortality. These chronic lung diseases are united by susceptibility to microbial colonization and recurrent airway infections. Whether these twinned phenomena (mucous metaplasia, compromised host defenses) are causally related has been unclear. Here, we demonstrate that SAM pointed domain ETS factor (SPDEF) was induced by rhinoviral infection of primary human airway cells and that cytoplasmic activities of SPDEF, a transcriptional regulator of airway goblet cell metaplasia, inhibited Toll-like receptor (TLR) activation of epithelial cells. SPDEF bound to and inhibited activities of TLR signaling adapters, MyD88 and TRIF, inhibiting MyD88-induced cytokine production and TRIF-induced interferon ß production. Conditional expression of SPDEF in airway epithelial cells in vivo inhibited LPS-induced neutrophilic infiltration and bacterial clearance. SPDEF-mediated inhibition of both TLR and type I interferon signaling likely protects the lung against inflammatory damage when inciting stimuli are not eradicated. Present findings provide, at least in part, a molecular explanation for increased susceptibility to infection in lung diseases associated with mucous metaplasia and a mechanism by which patients with florid mucous metaplasia may tolerate microbial burdens that are usually associated with fulminant inflammatory disease in normal hosts.


Asunto(s)
Células Epiteliales/metabolismo , Proteínas Proto-Oncogénicas c-ets/metabolismo , Mucosa Respiratoria/metabolismo , Transducción de Señal , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Antibacterianos/farmacología , Western Blotting , Doxiciclina/farmacología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/virología , Expresión Génica/efectos de los fármacos , Células HEK293 , Interacciones Huésped-Patógeno , Humanos , Inmunidad Innata , Interleucina-13/farmacología , Lipopolisacáridos/farmacología , Enfermedades Pulmonares/tratamiento farmacológico , Enfermedades Pulmonares/metabolismo , Enfermedades Pulmonares/patología , Metaplasia , Ratones , Microscopía Confocal , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas c-ets/genética , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rhinovirus/fisiología , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo
4.
Am J Physiol Lung Cell Mol Physiol ; 306(8): L726-35, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24508732

RESUMEN

A number of growth factors and signaling pathways regulate matrix deposition and fibroblast proliferation in the lung. The epidermal growth factor receptor (EGFR) family of receptors and the transforming growth factor-ß (TGF-ß) family are active in diverse biological processes and are central mediators in the initiation and maintenance of fibrosis in many diseases. Transforming growth factor-α (TGF-α) is a ligand for the EGFR, and doxycycline (Dox)-inducible transgenic mice conditionally expressing TGF-α specifically in the lung epithelium develop progressive fibrosis accompanied with cachexia, changes in lung mechanics, and marked pleural thickening. Although recent studies demonstrate that EGFR activation modulates the fibroproliferative effects involved in the pathogenesis of TGF-ß induced pulmonary fibrosis, in converse, the direct role of EGFR induction of the TGF-ß pathway in the lung is unknown. The αvß6 integrin is an important in vivo activator of TGF-ß activation in the lung. Immunohistochemical analysis of αvß6 protein expression and bronchoalveolar analysis of TGF-ß pathway signaling indicates activation of the αvß6/TGF-ß pathway only at later time points after lung fibrosis was already established in the TGF-α model. To determine the contribution of the αvß6/TGF-ß pathway on the progression of established fibrotic disease, TGF-α transgenic mice were administered Dox for 4 wk, which leads to extensive fibrosis; these mice were then treated with a function-blocking anti-αvß6 antibody with continued administration of Dox for an additional 4 wk. Compared with TGF-α transgenic mice treated with control antibody, αvß6 inhibition significantly attenuated pleural thickening and altered the decline in lung mechanics. To test the effects of genetic loss of the ß6 integrin, TGF-α transgenic mice were mated with ß6-null mice and the degree of fibrosis was compared in adult mice following 8 wk of Dox administration. Genetic ablation of the ß6 integrin attenuated histological and physiological changes in the lungs of TGF-α transgenic mice although a significant degree of fibrosis still developed. In summary, inhibition of the ß6 integrin led to a modest, albeit significant, effect on pleural thickening and lung function decline observed with TGF-α-induced pulmonary fibrosis. These data support activation of the αvß6/TGF-ß pathway as a secondary effect contributing to TGF-α-induced pleural fibrosis and suggest a complex contribution of multiple mediators to the maintenance of progressive fibrosis in the lung.


Asunto(s)
Integrinas/antagonistas & inhibidores , Fibrosis Pulmonar/patología , Factor de Crecimiento Transformador alfa/farmacología , Animales , Antibacterianos/toxicidad , Anticuerpos Neutralizantes , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Lavado Broncoalveolar , Colágeno , Doxiciclina/toxicidad , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Técnicas para Inmunoenzimas , Integrinas/genética , Integrinas/metabolismo , Masculino , Ratones , Ratones Transgénicos , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/metabolismo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Crecimiento Transformador beta/farmacología , Uteroglobina/fisiología
5.
Am J Physiol Gastrointest Liver Physiol ; 307(5): G499-507, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24994859

RESUMEN

Resistin-like molecule (Relm)-α is a secreted, cysteine-rich protein belonging to a newly defined family of proteins, including resistin, Relm-ß, and Relm-γ. Although resistin was initially defined based on its insulin-resistance activity, the family members are highly induced in various inflammatory states. Earlier studies implicated Relm-α in insulin resistance, asthmatic responses, and intestinal inflammation; however, its function still remains an enigma. We now report that Relm-α is strongly induced in the esophagus in an allergen-challenged murine model of eosinophilic esophagitis (EoE). Furthermore, to understand the in vivo role of Relm-α, we generated Relm-α gene-inducible bitransgenic mice by using lung-specific CC-10 promoter (CC10-rtTA-Relm-α). We found Relm-α protein is significantly induced in the esophagus of CC10-rtTA-Relm-α bitransgenic mice exposed to doxycycline food. The most prominent effect observed by the induction of Relm-α is epithelial cell hyperplasia, basal layer thickness, accumulation of activated CD4(+) and CD4(-) T cell subsets, and eosinophilic inflammation in the esophagus. The in vitro experiments further confirm that Relm-α promotes primary epithelial cell proliferation but has no chemotactic activity for eosinophils. Taken together, our studies report for the first time that Relm-α induction in the esophagus has a major role in promoting epithelial cell hyperplasia and basal layer thickness, and the accumulation of activated CD4(+) and CD4(-) T cell subsets may be responsible for partial esophageal eosinophilia in the mouse models of EoE. Notably, the epithelial cell hyperplasia and basal layer thickness are the characteristic features commonly observed in human EoE.


Asunto(s)
Alérgenos/toxicidad , Doxiciclina/toxicidad , Esofagitis Eosinofílica/metabolismo , Células Epiteliales/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Animales , Recuento de Linfocito CD4 , Proliferación Celular , Células Cultivadas , Quimiotaxis , Esofagitis Eosinofílica/inmunología , Esofagitis Eosinofílica/patología , Eosinófilos/fisiología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/patología , Esófago/efectos de los fármacos , Esófago/metabolismo , Esófago/patología , Hiperplasia/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Ratones , Ratones Endogámicos BALB C
6.
Am J Respir Cell Mol Biol ; 49(5): 845-54, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23795648

RESUMEN

Pulmonary surfactant protein-C (SP-C) gene-targeted mice (Sftpc(-/-)) develop progressive lung inflammation and remodeling. We hypothesized that SP-C deficiency reduces the ability to suppress repetitive inflammatory injury. Sftpc(+/+) and Sftpc(-/-) mice given three doses of bacterial LPS developed airway and airspace inflammation, which was more intense in the Sftpc(-/-) mice at 3 and 5 days after the final dose. Compared with Sftpc(+/+)mice, inflammatory injury persisted in the lungs of Sftpc(-/-) mice 30 days after the final LPS challenge. Sftpc(-/-) mice showed LPS-induced airway goblet cell hyperplasia with increased detection of Sam pointed Ets domain and FoxA3 transcription factors. Sftpc(-/-) type II alveolar epithelial cells had increased cytokine expression after LPS exposure relative to Sftpc(+/+) cells, indicating that type II cell dysfunction contributes to inflammatory sensitivity. Microarray analyses of isolated type II cells identified a pattern of enhanced expression of inflammatory genes consistent with an intrinsic low-level inflammation resulting from SP-C deficiency. SP-C-containing clinical surfactant extract (Survanta) or SP-C/phospholipid vesicles blocked LPS signaling through the LPS receptor (Toll-like receptor [TLR] 4/CD14/MD2) in human embryonic kidney 293T cells, indicating that SP-C blocks LPS-induced cytokine production by a TLR4-dependent mechanism. Phospholipid vesicles alone did not modify the TLR4 response. In vivo deficiency of SP-C leads to inflammation, increased cytokine production by type II cells, and persistent inflammation after repetitive LPS stimulation.


Asunto(s)
Endotoxinas , Pulmón/metabolismo , Péptidos/deficiencia , Neumonía/metabolismo , Células Epiteliales Alveolares/inmunología , Células Epiteliales Alveolares/metabolismo , Células Epiteliales Alveolares/patología , Animales , Productos Biológicos/farmacología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Células Caliciformes/inmunología , Células Caliciformes/metabolismo , Células Caliciformes/patología , Células HEK293 , Factor Nuclear 3-gamma del Hepatocito/metabolismo , Humanos , Hiperplasia , Inmunidad Innata , Mediadores de Inflamación/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Receptores de Lipopolisacáridos/metabolismo , Pulmón/efectos de los fármacos , Pulmón/inmunología , Pulmón/patología , Ratones , Ratones de la Cepa 129 , Ratones Noqueados , Péptidos/genética , Neumonía/inducido químicamente , Neumonía/genética , Neumonía/inmunología , Neumonía/patología , Proteínas Proto-Oncogénicas c-ets/metabolismo , Proteína C Asociada a Surfactante Pulmonar , Transducción de Señal , Factores de Tiempo , Receptor Toll-Like 4/metabolismo
7.
Respir Res ; 14: 19, 2013 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-23399055

RESUMEN

BACKGROUND: Individuals with deficiencies of pulmonary surfactant protein C (SP-C) develop interstitial lung disease (ILD) that is exacerbated by viral infections including respiratory syncytial virus (RSV). SP-C gene targeted mice (Sftpc -/-) lack SP-C, develop an ILD-like disease and are susceptible to infection with RSV. METHODS: In order to determine requirements for correction of RSV induced injury we have generated compound transgenic mice where SP-C expression can be induced on the Sftpc -/- background (SP-C/Sftpc -/-) by the administration of doxycycline (dox). The pattern of induced SP-C expression was determined by immunohistochemistry and processing by Western blot analysis. Tissue and cellular inflammation was measured following RSV infection and the RSV-induced cytokine response of isolated Sftpc +/+ and -/- type II cells determined. RESULTS: After 5 days of dox administration transgene SP-C mRNA expression was detected by RT-PCR in the lungs of two independent lines of bitransgenic SP-C/Sftpc -/- mice (lines 55.3 and 54.2). ProSP-C was expressed in the lung, and mature SP-C was detected by Western blot analysis of the lavage fluid from both lines of SP-C/Sftpc -/- mice. Induced SP-C expression was localized to alveolar type II cells by immunostaining with an antibody to proSP-C. Line 55.3 SP-C/Sftpc -/- mice were maintained on or off dox for 7 days and infected with 2.6x107 RSV pfu. On day 3 post RSV infection total inflammatory cell counts were reduced in the lavage of dox treated 55.3 SP-C/Sftpc -/- mice (p = 0.004). The percentage of neutrophils was reduced (p = 0.05). The viral titers of lung homogenates from dox treated 55.3 SP-C/Sftpc -/- mice were decreased relative to 55.3 SP-C/Sftpc -/- mice without dox (p = 0.01). The cytokine response of Sftpc -/- type II cells to RSV was increased over that of Sftpc +/+ cells. CONCLUSIONS: Transgenic restoration of SP-C reduced inflammation and improved viral clearance in the lungs of SP-C deficient mice. The loss of SP-C in alveolar type II cells compromises their response to infection. These findings show that the restoration of SP-C in Sftpc -/- mice in response to RSV infection is a useful model to determine parameters for therapeutic intervention.


Asunto(s)
Lesión Pulmonar/metabolismo , Proteína C Asociada a Surfactante Pulmonar/genética , Infecciones por Virus Sincitial Respiratorio/genética , Virus Sincitiales Respiratorios , Animales , Células Cultivadas , Regulación hacia Abajo/genética , Lesión Pulmonar/genética , Lesión Pulmonar/prevención & control , Ratones , Ratones de la Cepa 129 , Ratones Transgénicos , Proteína C Asociada a Surfactante Pulmonar/biosíntesis , Infecciones por Virus Sincitial Respiratorio/metabolismo , Infecciones por Virus Sincitial Respiratorio/prevención & control , Carga Viral/métodos
8.
Respir Res ; 13: 51, 2012 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-22726462

RESUMEN

BACKGROUND: Resistin-like molecule alpha or found in inflammatory zone protein (Fizz1) is increased in pulmonary epithelial cells and also in limited amounts by other lung cells during various lung injuries and fibrosis. However, the direct role of Fizz1 produced in the pulmonary epithelium has not been determined. METHODS: Fizz1 Transgenic mice (CCSP/Fizz1) were generated that overexpress Fizz1 in the lung epithelium under the control of a doxycycline (Dox) inducible lung epithelial cell specific promoter Scgb1a1 (Clara cell secretory protein, CCSP). Histology and FACS analysis of lung cells were used to identify the direct effects of Fizz1 in the transgenic mice (Dox treated) when compared with control (CCSP/-) mice. Intratracheal bleomycin sulfate or silica in saline and saline alone were used to study the role of Fizz1 during bleomycin- and silica-induced pulmonary fibrosis in CCSP/Fizz1 and CCSP/- mice. Weight change, pulmonary inflammation, and fibrosis were assessed 10 days post bleomycin or 28 days post silica challenge. RESULTS: When CCSP/Fizz1 mice were fed Dox food, elevated Fizz1 protein was detected in lung homogenates by western blot. Lungs of mice in which Fizz1 was induced in the epithelium contained increased lung cells staining for CD11c and F4/80 by FACS analysis consistent with increased dendritic cells however, no changes were observed in the percentage of interstitial macrophages compared to CCSP/- controls. No significant changes were found in the lung histology of CCSP/Fizz1 mice after up to 8 weeks of overexpression compared to CCSP/- controls. Overexpression of Fizz1 prior to challenge or following challenge with bleomycin or silica did not significantly alter airway inflammation or fibrosis compared to control mice. CONCLUSIONS: The current study demonstrates that epithelial cell derived Fizz1 is sufficient to increase the bone-marrow derived dendritic cells in the lungs, but it is not sufficient to cause lung fibrosis or alter chemical or particle-induced fibrosis.


Asunto(s)
Movimiento Celular/fisiología , Células Dendríticas/metabolismo , Péptidos y Proteínas de Señalización Intercelular/fisiología , Pulmón/metabolismo , Pulmón/patología , Fibrosis Pulmonar , Animales , Células Dendríticas/patología , Femenino , Ratones , Ratones Transgénicos , Fibrosis Pulmonar/etiología , Fibrosis Pulmonar/patología
9.
Am J Respir Cell Mol Biol ; 44(2): 175-84, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20348208

RESUMEN

Surfactant protein A (SP-A) mediates innate immune cell responses to LPS, a cell wall component of gram-negative bacteria that is found ubiquitously in the environment and is associated with adverse health effects. Inhaled LPS induces lung inflammation and increases airway responsiveness (AR). However, the role of SP-A in mediating LPS-induced AR is not well-defined. Nitric oxide (NO) is described as a potent bronchodilator, and previous studies showed that SP-A modulates the LPS-induced production of NO. Hence, we tested the hypothesis that increased AR, observed in response to aerosolized LPS exposure, would be significantly reduced in an SP-A-deficient condition. Wild-type (WT) and SP-A null (SP-A(-/-)) mice were challenged with aerosolized LPS. Results indicate that despite similar inflammatory indices, LPS-treated SP-A(-/-) mice had attenuated AR after methacholine challenge, compared with WT mice. The attenuated AR could not be attributed to inherent differences in SP-D concentrations or airway smooth muscle contractile and relaxation properties, because these measures were similar between WT and SP-A(-/-) mice. LPS-treated SP-A(-/-) mice, however, had elevated nitrite concentrations, inducible nitric oxide synthase (iNOS) expression, and NOS activity in their lungs. Moreover, the administration of the iNOS-specific inhibitor 1400W completely abrogated the attenuated AR. Thus, when exposed to aerosolized LPS, SP-A(-/-) mice demonstrate a relative airway hyporesponsiveness that appears to be mediated at least partly via an iNOS-dependent mechanism. These findings may have clinical significance, because recent studies reported associations between surfactant protein polymorphisms and a variety of lung diseases.


Asunto(s)
Lipopolisacáridos/farmacología , Pulmón/inmunología , Pulmón/fisiopatología , Óxido Nítrico/fisiología , Proteína A Asociada a Surfactante Pulmonar/deficiencia , Animales , Inmunidad Innata , Pulmón/efectos de los fármacos , Cloruro de Metacolina/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteína A Asociada a Surfactante Pulmonar/genética , Proteína A Asociada a Surfactante Pulmonar/inmunología , Proteína A Asociada a Surfactante Pulmonar/fisiología , Proteína D Asociada a Surfactante Pulmonar/metabolismo
10.
Am J Physiol Lung Cell Mol Physiol ; 300(3): L414-21, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21224214

RESUMEN

Increases in the epidermal growth factor receptor (EGFR) have been associated with the severity of airway thickening in chronic asthmatic subjects, and EGFR signaling is induced by asthma-related cytokines and inflammation. The goal of this study was to determine the role of EGFR signaling in a chronic allergic model of asthma and specifically in epithelial cells, which are increasingly recognized as playing an important role in asthma. EGFR activation was assessed in mice treated with intranasal house dust mite (HDM) for 3 wk. EGFR signaling was inhibited in mice treated with HDM for 6 wk, by using either the drug erlotinib or a genetic approach that utilizes transgenic mice expressing a mutant dominant negative epidermal growth factor receptor in the lung epithelium (EGFR-M mice). Airway hyperreactivity (AHR) was assessed by use of a flexiVent system after increasing doses of nebulized methacholine. Airway smooth muscle (ASM) thickening was measured by morphometric analysis. Sensitization to HDM (IgG and IgE), inflammatory cells, and goblet cell changes were also assessed. Increased EGFR activation was detected in HDM-treated mice, including in bronchiolar epithelial cells. In mice exposed to HDM for 6 wk, AHR and ASM thickening were reduced after erlotinib treatment and in EGFR-M mice. Sensitization to HDM and inflammatory cell counts were similar in all groups, except neutrophil counts, which were lower in the EGFR-M mice. Goblet cell metaplasia with HDM treatment was reduced by erlotinib, but not in EGFR-M transgenic mice. This study demonstrates that EGFR signaling, especially in the airway epithelium, plays an important role in mediating AHR and remodeling in a chronic allergic asthma model.


Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Asma/fisiopatología , Hiperreactividad Bronquial/complicaciones , Células Epiteliales/enzimología , Receptores ErbB/metabolismo , Transducción de Señal , Animales , Asma/complicaciones , Asma/parasitología , Asma/patología , Hiperreactividad Bronquial/parasitología , Hiperreactividad Bronquial/patología , Hiperreactividad Bronquial/fisiopatología , Enfermedad Crónica , Modelos Animales de Enfermedad , Activación Enzimática , Células Epiteliales/patología , Receptores ErbB/antagonistas & inhibidores , Células Caliciformes/patología , Inflamación/complicaciones , Inflamación/patología , Pulmón/parasitología , Pulmón/patología , Pulmón/fisiopatología , Metaplasia , Ratones , Músculo Liso/patología , Pyroglyphidae/fisiología
11.
Am J Pathol ; 176(2): 679-86, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20042669

RESUMEN

Transforming growth factor-alpha (TGFalpha) is a ligand for the epidermal growth factor receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. EGFR signaling activates several intracellular signaling pathways including phosphatidylinositol 3'-kinase (PI3K). We previously showed that induction of lung-specific TGFalpha expression in transgenic mice caused progressive pulmonary fibrosis over a 4-week period. The increase in levels of phosphorylated Akt, detected after 1 day of doxycycline-induced TGFalpha expression, was blocked by treatment with the PI3K inhibitor, PX-866. Daily administration of PX-866 during TGFalpha induction prevented increases in lung collagen and airway resistance as well as decreases in lung compliance. Treatment of mice with oral PX-866 4 weeks after the induction of TGFalpha prevented additional weight loss and further increases in total collagen, and attenuated changes in pulmonary mechanics. These data show that PI3K is activated in TGFalpha/EGFR-mediated pulmonary fibrosis and support further studies to determine the role of PI3K activation in human lung fibrotic disease, which could be amenable to targeted therapy.


Asunto(s)
Gonanos/farmacología , Gonanos/uso terapéutico , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/prevención & control , Factor de Crecimiento Transformador alfa , Administración Oral , Animales , Progresión de la Enfermedad , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Gonanos/administración & dosificación , Ratones , Ratones Transgénicos , Proteína Oncogénica v-akt/metabolismo , Fosforilación/efectos de los fármacos , Uteroglobina/genética
12.
JCI Insight ; 6(7)2021 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-33830085

RESUMEN

The molecular mechanisms by which endothelial cells (ECs) regulate pulmonary vascularization and contribute to alveolar epithelial cell development during lung morphogenesis remain unknown. We tested the hypothesis that delta-like 4 (DLL4), an EC Notch ligand, is critical for alveolarization by combining lung mapping and functional studies in human tissue and DLL4-haploinsufficient mice (Dll4+/lacz). DLL4 expressed in a PECAM-restricted manner in capillaries, arteries, and the alveolar septum from the canalicular to alveolar stage in mice and humans. Dll4 haploinsufficiency resulted in exuberant, nondirectional vascular patterning at E17.5 and P6, followed by smaller capillaries and fewer intermediate blood vessels at P14. Vascular defects coincided with polarization of lung EC expression toward JAG1-NICD-HES1 signature and decreased tip cell-like (Car4) markers. Dll4+/lacZ mice had impaired terminal bronchiole development at the canalicular stage and impaired alveolarization upon lung maturity. We discovered that alveolar type I cell (Aqp5) markers progressively decreased in Dll4+/lacZ mice after birth. Moreover, in human lung EC, DLL4 deficiency programmed a hypersprouting angiogenic phenotype cell autonomously. In conclusion, DLL4 is expressed from the canalicular to alveolar stage in mice and humans, and Dll4 haploinsufficiency programs dysmorphic microvascularization, impairing alveolarization. Our study reveals an obligate role for DLL4-regulated angiogenesis in distal lung morphogenesis.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas de Unión al Calcio/metabolismo , Pulmón/irrigación sanguínea , Pulmón/embriología , Proteínas Adaptadoras Transductoras de Señales/genética , Células Epiteliales Alveolares/fisiología , Animales , Proteínas de Unión al Calcio/genética , Regulación del Desarrollo de la Expresión Génica , Haploinsuficiencia , Humanos , Hipoxia , Ratones Endogámicos C57BL , Ratones Mutantes , Neovascularización Fisiológica/genética , Alveolos Pulmonares/citología , Alveolos Pulmonares/embriología , Alveolos Pulmonares/metabolismo
13.
J Clin Invest ; 117(4): 978-88, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17347682

RESUMEN

Goblet cell hyperplasia and mucous hypersecretion contribute to the pathogenesis of chronic pulmonary diseases including cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In the present work, mouse SAM pointed domain-containing ETS transcription factor (SPDEF) mRNA and protein were detected in subsets of epithelial cells lining the trachea, bronchi, and tracheal glands. SPDEF interacted with the C-terminal domain of thyroid transcription factor 1, activating transcription of genes expressed selectively in airway epithelial cells, including Sftpa, Scgb1a1, Foxj1, and Sox17. Expression of Spdef in the respiratory epithelium of adult transgenic mice caused goblet cell hyperplasia, inducing both acidic and neutral mucins in vivo, and stainined for both acidic and neutral mucins in vivo. SPDEF expression was increased at sites of goblet cell hyperplasia caused by IL-13 and dust mite allergen in a process that was dependent upon STAT-6. SPDEF was induced following intratracheal allergen exposure and after Th2 cytokine stimulation and was sufficient to cause goblet cell differentiation of Clara cells in vivo.


Asunto(s)
Células Caliciformes/fisiología , Hiperplasia/fisiopatología , Proteínas Proto-Oncogénicas c-ets/genética , Mucosa Respiratoria/fisiología , Animales , Sitios de Unión , Diferenciación Celular , Línea Celular , Citocinas/fisiología , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/fisiología , Regulación de la Expresión Génica , Variación Genética , Células Caliciformes/citología , Historia del Siglo XVI , Humanos , Pulmón/crecimiento & desarrollo , Pulmón/fisiología , Neoplasias Pulmonares , Ratones , Proteínas Proto-Oncogénicas c-ets/metabolismo , Proteínas Proto-Oncogénicas c-ets/fisiología , ARN Mensajero/genética , Mucosa Respiratoria/patología , Mucosa Respiratoria/fisiopatología , Células Th2/fisiología , Tráquea/fisiología , Factores de Transcripción , Transcripción Genética
14.
Am J Respir Crit Care Med ; 180(9): 834-45, 2009 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-19661247

RESUMEN

RATIONALE: Induced mainly by cigarette smoking, chronic obstructive pulmonary disease (COPD) is a global public health problem characterized by progressive difficulty in breathing and increased mucin production. Previously, we reported that acrolein levels found in COPD sputum could activate matrix metalloproteinase-9 (MMP9). OBJECTIVES: To determine whether acrolein increases expression and activity of MMP14, a critical membrane-bound endopeptidase that can initial a MMP-activation cascade. METHODS: MMP14 activity and adduct formation were measured following direct acrolein treatment. MMP14 expression and activity was measured in human airway epithelial cells. MMP14 immunohistochemistry was performed with COPD tissue, and in acrolein- or tobacco-exposed mice. MEASUREMENTS AND MAIN RESULTS: In a cell-free system, acrolein, in concentrations equal to those found in COPD sputum, directly adducted cysteine 319 in the MMP14 hemopexin-like domain and activated MMP14. In cells, acrolein increased MMP14 activity, which was inhibited by a proprotein convertase inhibitor, hexa-d-arginine. In the airway epithelium of COPD subjects, immunoreactive MMP14 protein increased. In mouse lung, acrolein or tobacco smoke increased lung MMP14 activity and protein. In cells, acrolein-induced MMP14 transcripts were inhibited by an epidermal growth factor receptor (EGFR) neutralizing antibody, EGFR kinase inhibitor, metalloproteinase inhibitor, or mitogen-activated protein kinase (MAPK) 3/2 or MAPK8 inhibitors, but not a MAPK14 inhibitor. Decreasing the MMP14 protein and activity in vitro by small interfering (si)RNA to MMP14 diminished the acrolein-induced MUC5AC transcripts. In acrolein-exposed mice or transgenic mice with lung-specific transforming growth factor-alpha (an EGFR ligand) expression, lung MMP14 and MUC5AC levels increased and these effects were inhibited by a EGFR inhibitor, erlotinib. CONCLUSIONS: Taken together, these findings implicate acrolein-induced MMP14 expression and activity in mucin production in COPD.


Asunto(s)
Metaloproteinasa 14 de la Matriz/metabolismo , Mucinas/biosíntesis , Mucosa Respiratoria/metabolismo , Acroleína/metabolismo , Animales , Activación Enzimática , Células Epiteliales/metabolismo , Células Epiteliales/ultraestructura , Clorhidrato de Erlotinib , Regulación Enzimológica de la Expresión Génica , Humanos , Pulmón/enzimología , Pulmón/metabolismo , Ratones , Mucinas/metabolismo , Inhibidores de Proteínas Quinasas/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Quinazolinas/metabolismo , Mucosa Respiratoria/ultraestructura
15.
Am J Respir Cell Mol Biol ; 41(5): 562-72, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19244201

RESUMEN

Transforming growth factor (TGF)-alpha is a ligand for the epidermal growth factor receptor (EGFR). EGFR activation is associated with fibroproliferative processes in human lung disease and animal models of pulmonary fibrosis. Overexpression of TGF-alpha in transgenic mice causes progressive and severe pulmonary fibrosis; however, the intracellular signaling pathways downstream of EGFR mediating this response are unknown. Using a doxycycline-regulatable transgenic mouse model of lung-specific TGF-alpha expression, we observed increased PCNA protein and phosphorylation of Akt and p70S6K in whole lung homogenates in association with induction of TGF-alpha. Induction in the lung of TGF-alpha caused progressive pulmonary fibrosis over a 7-week period. Daily administration of rapamycin prevented accumulation of total lung collagen, weight loss, and changes in pulmonary mechanics. Treatment of mice with rapamycin 4 weeks after the induction of TGF-alpha prevented additional weight loss, increases in total collagen, and changes in pulmonary mechanics. Rapamycin prevented further increases in established pulmonary fibrosis induced by EGFR activation. This study demonstrates that mammalian target of rapamycin (mTOR) is a major effector of EGFR-induced pulmonary fibrosis, providing support for further studies to determine the role of mTOR in the pathogenesis and treatment of pulmonary fibrosis.


Asunto(s)
Proteínas Portadoras/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Pulmón/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Fibrosis Pulmonar/prevención & control , Transducción de Señal/efectos de los fármacos , Sirolimus/farmacología , Factor de Crecimiento Transformador alfa/metabolismo , Animales , Proteínas Portadoras/metabolismo , Colágeno/metabolismo , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Doxiciclina/farmacología , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/metabolismo , Clorhidrato de Erlotinib , Regulación de la Expresión Génica , Humanos , Pulmón/enzimología , Pulmón/fisiopatología , Ratones , Ratones Transgénicos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Antígeno Nuclear de Célula en Proliferación/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fibrosis Pulmonar/genética , Fibrosis Pulmonar/metabolismo , Fibrosis Pulmonar/fisiopatología , Quinazolinas/farmacología , Mecánica Respiratoria/efectos de los fármacos , Proteínas Quinasas S6 Ribosómicas 70-kDa/metabolismo , Serina-Treonina Quinasas TOR , Factores de Tiempo , Factor de Crecimiento Transformador alfa/genética , Uteroglobina/genética
16.
Am J Respir Cell Mol Biol ; 41(4): 415-25, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19188657

RESUMEN

Transforming growth factor (TGF)-alpha and its receptor, the epidermal growth factor receptor, are induced after lung injury and are associated with remodeling in chronic pulmonary diseases, such as pulmonary fibrosis and asthma. Expression of TGF-alpha in the lungs of adult mice causes fibrosis, pleural thickening, and pulmonary hypertension, in addition to increased expression of a transcription factor, early growth response-1 (Egr-1). Egr-1 was increased in airway smooth muscle (ASM) and the vascular adventitia in the lungs of mice conditionally expressing TGF-alpha in airway epithelium (Clara cell secretory protein-rtTA(+/-)/[tetO](7)-TGF-alpha(+/-)). The goal of this study was to determine the role of Egr-1 in TGF-alpha-induced lung disease. To accomplish this, TGF-alpha-transgenic mice were crossed to Egr-1 knockout (Egr-1(ko/ko)) mice. The lack of Egr-1 markedly increased the severity of TGF-alpha-induced pulmonary disease, dramatically enhancing airway muscularization, increasing pulmonary fibrosis, and causing greater airway hyperresponsiveness to methacholine. Smooth muscle hyperplasia, not hypertrophy, caused the ASM thickening in the absence of Egr-1. No detectable increases in pulmonary inflammation were found. In addition to the airway remodeling disease, vascular remodeling and pulmonary hypertension were also more severe in Egr-1(ko/ko) mice. Thus, Egr-1 acts to suppress epidermal growth factor receptor-mediated airway and vascular muscularization, fibrosis, and airway hyperresponsiveness in the absence of inflammation. This provides a unique model to study the processes causing pulmonary fibrosis and ASM thickening without the complicating effects of inflammation.


Asunto(s)
Hiperreactividad Bronquial/fisiopatología , Proteína 1 de la Respuesta de Crecimiento Precoz/fisiología , Pulmón/patología , Fibrosis Pulmonar/patología , Factor de Crecimiento Transformador alfa/fisiología , Resistencia de las Vías Respiratorias , Albuterol/farmacología , Animales , Hiperreactividad Bronquial/inducido químicamente , Hiperreactividad Bronquial/genética , Células Cultivadas/efectos de los fármacos , Células Cultivadas/patología , Modelos Animales de Enfermedad , Proteína 1 de la Respuesta de Crecimiento Precoz/biosíntesis , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Receptores ErbB/antagonistas & inhibidores , Fibroblastos/citología , Humanos , Hiperplasia , Rendimiento Pulmonar , Cloruro de Metacolina/toxicidad , Ratones , Ratones Noqueados , Ratones Transgénicos , Músculo Liso/patología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/patología , Arteria Pulmonar/citología , Fibrosis Pulmonar/genética , Fibrosis Pulmonar/fisiopatología , Proteínas Recombinantes de Fusión/fisiología , Factor de Crecimiento Transformador alfa/efectos adversos , Pérdida de Peso
17.
Am J Respir Cell Mol Biol ; 41(2): 226-36, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19131640

RESUMEN

The etiology of acute lung injury is complex and associated with numerous, chemically diverse precipitating factors. During acute lung injury in mice, one key event is epithelial cell injury that leads to reduced surfactant biosynthesis. We have previously reported that transgenic mice that express transforming growth factor alpha (TGFA) in the lung were protected during nickel-induced lung injury. Here, we find that the mechanism by which TGFA imparts protection includes maintenance of surfactant-associated protein B (SFTPB) transcript levels and epidermal growth factor receptor-dependent signaling in distal pulmonary epithelial cells. This protection is complex and not accompanied by a diminution in inflammatory mediator transcripts or additional stimulation of antioxidant transcripts. In mouse lung epithelial (MLE-15) cells, microarray analysis demonstrated that nickel increased transcripts of genes enriched in MTF1, E2F-1, and AP-2 transcription factor-binding sites and decreased transcripts of genes enriched in AP-1-binding sites. Nickel also increased Jun transcript and DNA-binding activity, but decreased SFTPB transcript. Expression of SFTPB under the control of a doxycycline-sensitive promoter increased survival during nickel-induced injury as compared with control mice. Together, these findings support the idea that maintenance of SFTPB expression is critical to survival during acute lung injury.


Asunto(s)
Lesión Pulmonar Aguda/inducido químicamente , Níquel/toxicidad , Proteína B Asociada a Surfactante Pulmonar/metabolismo , Administración por Inhalación , Aerosoles , Animales , Células Cultivadas , Células Epiteliales/citología , Células Epiteliales/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Ratones Transgénicos , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , Proteína B Asociada a Surfactante Pulmonar/genética , Mucosa Respiratoria/citología , Tasa de Supervivencia , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismo , Factor de Crecimiento Transformador alfa/genética , Factor de Crecimiento Transformador alfa/metabolismo
18.
Am J Physiol Lung Cell Mol Physiol ; 297(1): L64-72, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19304906

RESUMEN

Patients with mutations in the pulmonary surfactant protein C (SP-C) gene develop interstitial lung disease and pulmonary exacerbations associated with viral infections including respiratory syncytial virus (RSV). Pulmonary infection with RSV caused more severe interstitial thickening, air space consolidation, and goblet cell hyperplasia in SP-C-deficient (Sftpc(-/-)) mice compared with SP-C replete mice. The RSV-induced pathology resolved more slowly in Sftpc(-/-) mice with lung inflammation persistent up to 30 days postinfection. Polymorphonuclear leukocyte and macrophage counts were increased in the bronchoalveolar lavage (BAL) fluid of Sftpc(-/-) mice. Viral titers and viral F and G protein mRNA were significantly increased in both Sftpc(-/-) and heterozygous Sftpc(+/-) mice compared with controls. Expression of Toll-like receptor 3 (TLR3) mRNA was increased in the lungs of Sftpc(-/-) mice relative to Sftpc(+/+) mice before and after RSV infection. Consistent with the increased TLR3 expression, BAL inflammatory cells were increased in the Sftpc(-/-) mice after exposure to a TLR3-specific ligand, poly(I:C). Preparations of purified SP-C and synthetic phospholipids blocked poly(I:C)-induced TLR3 signaling in vitro. SP-C deficiency increases the severity of RSV-induced pulmonary inflammation through regulation of TLR3 signaling.


Asunto(s)
Proteína C Asociada a Surfactante Pulmonar/deficiencia , Infecciones por Virus Sincitial Respiratorio/metabolismo , Infecciones por Virus Sincitial Respiratorio/patología , Animales , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/virología , Recuento de Células , Línea Celular , Colectinas/metabolismo , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Regulación Viral de la Expresión Génica , Células Caliciformes/patología , Células Caliciformes/virología , Humanos , Hipertrofia , Ligandos , Pulmón/metabolismo , Pulmón/patología , Pulmón/virología , Ratones , Neumonía/complicaciones , Neumonía/patología , Neumonía/virología , Proteína C Asociada a Surfactante Pulmonar/metabolismo , ARN Bicatenario/metabolismo , Infecciones por Virus Sincitial Respiratorio/complicaciones , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitiales Respiratorios/genética , Factores de Tiempo , Receptor Toll-Like 3/metabolismo
19.
J Appl Physiol (1985) ; 106(5): 1545-52, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19265061

RESUMEN

Surfactant protein (SP)-D plays an important role in host defense and pulmonary surfactant homeostasis. In SP-D-deficient (Sftpd(-/-)) mice, the abnormal large surfactant forms seen at the ultrastructural level are taken up inefficiently by type II cells, resulting in an over threefold increase in the surfactant pool size. The mechanisms by which SP-D influences surfactant ultrastructure are unknown. We hypothesized that SP-D binds to surfactant immediately after being secreted and influences surfactant ultrastructure conversion. In newborn and adult sheep lungs, immunogold-labeled SP-D was associated with both lamellated membranous lipid structures of newly secreted surfactant and with small aggregate surfactant but not with tubular myelin. Since SP-D preferentially binds to phosphatidylinositol (PI) in vitro, the postnatal changes in PI were assessed. PI content in the bronchoalveolar lavage fluid increased after birth and peaked at 2-5 days of age, a time of rapid conversion of surfactant forms that is associated with the peak of surfactant lipid pool size. SP-D selectively interacted with PI-rich liposomes in vitro, causing their lysis. Similarly, the abnormal surfactant ultrastructure in Sftpd(-/-) mice was corrected by the addition of SP-D or melittin, and both peptides caused lysis of lipid vesicles. The normal conversion of surfactant ultrastructure requires SP-D that preferentially interacts with PI-rich, newly secreted surfactant, causing lysis of surfactant lipid membranes, converting the lipid forms into smaller surfactant lamellated structures that are critical for surfactant uptake by type II cells and normal surfactant homeostasis. SP-D regulates the dramatic decreases in the surfactant pool size that occurs in the newborn period.


Asunto(s)
Pulmón/metabolismo , Lípidos de la Membrana/metabolismo , Fosfatidilcolinas/metabolismo , Proteína D Asociada a Surfactante Pulmonar/metabolismo , Surfactantes Pulmonares/metabolismo , Factores de Edad , Animales , Animales Recién Nacidos , Líquido del Lavado Bronquioalveolar/química , Gránulos Citoplasmáticos/metabolismo , Gránulos Citoplasmáticos/ultraestructura , Modelos Animales de Enfermedad , Humanos , Inmunohistoquímica , Pulmón/efectos de los fármacos , Pulmón/crecimiento & desarrollo , Meliteno/metabolismo , Meliteno/farmacología , Ratones , Ratones Noqueados , Fosfatidilcolinas/análisis , Proteína D Asociada a Surfactante Pulmonar/deficiencia , Proteína D Asociada a Surfactante Pulmonar/farmacología , Proteínas Recombinantes , Ovinos
20.
Am J Respir Cell Mol Biol ; 38(4): 446-54, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18006877

RESUMEN

Chronic obstructive pulmonary disease (COPD), a global public health problem, is characterized by progressive difficulty in breathing, with increased mucin production, especially in the small airways. Acrolein, a constituent of cigarette smoke and an endogenous mediator of oxidative stress, increases airway mucin 5, subtypes A and C (MUC5AC) production; however, the mechanism remains unclear. In this study, increased mMUC5AC transcripts and protein were associated with increased lung matrix metalloproteinase 9 (mMMP9) transcripts, protein, and activity in acrolein-exposed mice. Increased mMUC5AC transcripts and mucin protein were diminished in gene-targeted Mmp9 mice [Mmp9((-/-))] or in mice treated with an epidermal growth factor receptor (EGFR) inhibitor, erlotinib. Acrolein also decreased mTissue inhibitor of metalloproteinase protein 3 (an MMP9 inhibitor) transcript levels. In a cell-free system, acrolein increased pro-hMMP9 cleavage and activity in concentrations (100-300 nM) found in sputum from subjects with COPD. Acrolein increased hMMP9 transcripts in human airway cells, which was inhibited by an MMP inhibitor, EGFR-neutralizing antibody, or a mitogen-activated protein kinase (MAPK) 3/2 inhibitor. Together these findings indicate that acrolein can initiate cleavage of pro-hMMP9 and EGFR/MAPK signaling that leads to additional MMP9 formation. Augmentation of hMMP9 activity, in turn, could contribute to persistent excessive mucin production.


Asunto(s)
Acroleína/farmacología , Metaloproteinasa 9 de la Matriz/metabolismo , Mucinas/biosíntesis , Animales , Activación Enzimática/efectos de los fármacos , Receptores ErbB/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Humanos , Pulmón/efectos de los fármacos , Pulmón/enzimología , Pulmón/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Metaloproteinasa 9 de la Matriz/genética , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Mucina 5AC , Mucinas/genética , Mucinas/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/enzimología , Enfermedad Pulmonar Obstructiva Crónica/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Esputo/efectos de los fármacos , Esputo/enzimología , Inhibidor Tisular de Metaloproteinasa-3/genética , Inhibidor Tisular de Metaloproteinasa-3/metabolismo
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