Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Nat Commun ; 6: 6574, 2015 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-25762200

RESUMO

Activation of the NLRP3 inflammasome and subsequent maturation of IL-1ß have been implicated in acute lung injury (ALI), resulting in inflammation and fibrosis. We investigated the role of vimentin, a type III intermediate filament, in this process using three well-characterized murine models of ALI known to require NLRP3 inflammasome activation. We demonstrate that central pathophysiologic events in ALI (inflammation, IL-1ß levels, endothelial and alveolar epithelial barrier permeability, remodelling and fibrosis) are attenuated in the lungs of Vim(-/-) mice challenged with LPS, bleomycin and asbestos. Bone marrow chimeric mice lacking vimentin have reduced IL-1ß levels and attenuated lung injury and fibrosis following bleomycin exposure. Furthermore, decreased active caspase-1 and IL-1ß levels are observed in vitro in Vim(-/-) and vimentin-knockdown macrophages. Importantly, we show direct protein-protein interaction between NLRP3 and vimentin. This study provides insights into lung inflammation and fibrosis and suggests that vimentin may be a key regulator of the NLRP3 inflammasome.


Assuntos
Proteínas de Transporte/metabolismo , Inflamassomos/metabolismo , Inflamação/metabolismo , Vimentina/metabolismo , Lesão Pulmonar Aguda/metabolismo , Animais , Bleomicina/química , Células da Medula Óssea/citologia , Líquido da Lavagem Broncoalveolar , Linhagem Celular , Proliferação de Células , Feminino , Fibrose , Interleucina-1beta/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Knockout , Microscopia de Força Atômica , Proteína 3 que Contém Domínio de Pirina da Família NLR , Mapeamento de Interação de Proteínas
2.
J Clin Invest ; 124(7): 2935-46, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24865431

RESUMO

Acute exposure to particulate matter (PM) air pollution causes thrombotic cardiovascular events, leading to increased mortality rates; however, the link between PM and cardiovascular dysfunction is not completely understood. We have previously shown that the release of IL-6 from alveolar macrophages is required for a prothrombotic state and acceleration of thrombosis following exposure to PM. Here, we determined that PM exposure results in the systemic release of catecholamines, which engage the ß2-adrenergic receptor (ß2AR) on murine alveolar macrophages and augment the release of IL-6. In mice, ß2AR signaling promoted the development of a prothrombotic state that was sufficient to accelerate arterial thrombosis. In primary human alveolar macrophages, administration of a ß2AR agonist augmented IL-6 release, while the addition of a beta blocker inhibited PM-induced IL-6 release. Genetic loss or pharmacologic inhibition of the ß2AR on murine alveolar macrophages attenuated PM-induced IL-6 release and prothrombotic state. Furthermore, exogenous ß2AR agonist therapy further augmented these responses in alveolar macrophages through generation of mitochondrial ROS and subsequent increase of adenylyl cyclase activity. Together, these results link the activation of the sympathetic nervous system by ß2AR signaling with metabolism, lung inflammation, and an enhanced susceptibility to thrombotic cardiovascular events.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Agonistas de Receptores Adrenérgicos beta 2/efeitos adversos , Interleucina-6/biossíntese , Material Particulado/administração & dosagem , Material Particulado/efeitos adversos , Trombose/etiologia , Adenilil Ciclases/biossíntese , Animais , Antitrombina III/biossíntese , Líquido da Lavagem Broncoalveolar/química , Catecolaminas/biossíntese , Colforsina/administração & dosagem , Humanos , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/fisiologia , Masculino , Camundongos , Camundongos Knockout , Peptídeo Hidrolases/biossíntese , Propranolol/administração & dosagem , Propranolol/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo , Receptores Adrenérgicos beta/deficiência , Receptores Adrenérgicos beta/genética , Receptores Adrenérgicos beta 1/deficiência , Receptores Adrenérgicos beta 1/genética
3.
Proc Natl Acad Sci U S A ; 111(19): 7090-5, 2014 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-24778222

RESUMO

Cellular senescence restricts the proliferative capacity of cells and is accompanied by the production of several proteins, collectively termed the "senescence-messaging secretome" (SMS). As senescent cells accumulate in tissue, local effects of the SMS have been hypothesized to disrupt tissue regenerative capacity. Klotho functions as an aging-suppressor gene, and Klotho-deficient (kl/kl) mice exhibit an accelerated aging-like phenotype that includes a truncated lifespan, arteriosclerosis, and emphysema. Because plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor (SERPIN), is elevated in kl/kl mice and is a critical determinant of replicative senescence in vitro, we hypothesized that a reduction in extracellular proteolytic activity contributes to the accelerated aging-like phenotype of kl/kl mice. Here we show that PAI-1 deficiency retards the development of senescence and protects organ structure and function while prolonging the lifespan of kl/kl mice. These findings indicate that a SERPIN-regulated cell-nonautonomous proteolytic cascade is a critical determinant of senescence in vivo.


Assuntos
Envelhecimento/fisiologia , Glucuronidase/genética , Glucuronidase/metabolismo , Transtornos Hemorrágicos , Inibidor 1 de Ativador de Plasminogênio/deficiência , Serpina E2/genética , Serpina E2/metabolismo , Animais , Senescência Celular/fisiologia , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Espaço Extracelular/metabolismo , Feminino , Fator de Crescimento de Fibroblastos 23 , Transtornos Hemorrágicos/genética , Transtornos Hemorrágicos/metabolismo , Transtornos Hemorrágicos/mortalidade , Proteínas Klotho , Longevidade/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Proteólise , Telômero/fisiologia
4.
Nat Immunol ; 14(5): 461-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23525087

RESUMO

Inflammation is essential for host defense but can cause tissue damage and organ failure if unchecked. How the inflammation is resolved remains elusive. Here we report that the transcription factor Miz1 was required for terminating lipopolysaccharide (LPS)-induced inflammation. Genetic disruption of the Miz1 POZ domain, which is essential for the transactivation or repression activity of Miz1, resulted in hyperinflammation, lung injury and greater mortality in LPS-treated mice but a lower bacterial load and mortality in mice with Pseudomonas aeruginosa pneumonia. Loss of the Miz1 POZ domain prolonged the expression of proinflammatory cytokines. After stimulation, Miz1 was phosphorylated at Ser178, which was required for recruitment of the histone deacetylase HDAC1 to repress transcription of the gene encoding C/EBP-δ, an amplifier of inflammation. Our data provide a long-sought mechanism underlying the resolution of LPS-induced inflammation.


Assuntos
Lesão Pulmonar Aguda/imunologia , Proteína delta de Ligação ao Facilitador CCAAT/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Inibidoras de STAT Ativados/metabolismo , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Lesão Pulmonar Aguda/genética , Animais , Citocinas/metabolismo , Repressão Enzimática/genética , Histona Desacetilase 1/metabolismo , Tolerância Imunológica , Inflamação/genética , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutagênese Sítio-Dirigida , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Fosforilação , Proteínas Inibidoras de STAT Ativados/genética , Infecções por Pseudomonas/genética , Proteínas Repressoras/genética , Ativação Transcricional/genética , Ubiquitina-Proteína Ligases
5.
PLoS One ; 7(4): e35788, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22536437

RESUMO

RATIONALE: HMG-CoA reductase inhibitors such as rosuvastatin may have immunomodulatory and anti-inflammatory effects that may reduce the severity of influenza A infection. We hypothesized that rosuvastatin would decrease viral replication, attenuate lung injury, and improve mortality following influenza A infection in mice. METHODS: C57Bl/6 mice were treated daily with rosuvastatin (10 mg/kg/day) supplemented in chow (or control chow) beginning three days prior to infection with either A//Udorn/72 [H3N2] or A/WSN/33 [H1N1] influenza A virus (1×10(5) pfu/mouse). Plaque assays were used to examine the effect of rosuvastatin on viral replication in vitro and in the lungs of infected mice. We measured cell count with differential, protein and cytokines in the bronchoalveolar lavage (BAL) fluid, histologic evidence of lung injury, and wet-to-dry ratio on Day 1, 2, 4, and 6. We also recorded daily weights and mortality. RESULTS: The administration of rosuvastatin had no effect on viral clearance of influenza A after infection. Weight loss, lung inflammation and lung injury severity were similar in the rosuvastatin and control treated mice. In the mice infected with influenza A (A/WSN/33), mortality was unaffected by treatment with rosuvastatin. CONCLUSIONS: Statins did not alter the replication of influenza A in vitro or enhance its clearance from the lung in vivo. Statins neither attenuated the severity of influenza A-induced lung injury nor had an effect on influenza A-related mortality. Our data suggest that the association between HMG CoA reductase inhibitors and improved outcomes in patients with sepsis and pneumonia are not attributable to their effects on influenza A infection.


Assuntos
Antivirais/farmacologia , Fluorbenzenos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Pirimidinas/farmacologia , Sulfonamidas/farmacologia , Animais , Líquido da Lavagem Broncoalveolar/química , Linhagem Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/fisiologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Pneumonia/tratamento farmacológico , Pneumonia/metabolismo , Pneumonia/virologia , Rosuvastatina Cálcica , Replicação Viral/efeitos dos fármacos
6.
Sci Rep ; 2: 275, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22355787

RESUMO

Exposure of human populations to chronically elevated levels of ambient particulate matter air pollution < 2.5 µm in diameter (PM(2.5)) has been associated with an increase in lung cancer incidence. Over 70% of lung cancer cell lines exhibit promoter methylation of the tumor suppressor p16, an epigenetic modification that reduces its expression. We exposed mice to concentrated ambient PM(2.5) via inhalation, 8 hours daily for 3 weeks and exposed primary murine alveolar epithelial cells to daily doses of fine urban PM (5 µg/cm(2)). In both mice and alveolar epithelial cells, PM exposure increased ROS production, expression of the DNA methyltransferase 1 (DNMT1), and methylation of the p16 promoter. In alveolar epithelial cells, increased transcription of DNMT1 and methylation of the p16 promoter were inhibited by a mitochondrially targeted antioxidant and a JNK inhibitor. These findings provide a potential mechanism by which PM exposure increases the risk of lung cancer.

7.
PLoS One ; 7(1): e30448, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22272351

RESUMO

OBJECTIVE: Alcohol intake increases the risk of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) and is associated with poor outcomes in patients who develop these syndromes. No specific therapies are currently available to treat or decrease the risk of ARDS in patients with alcoholism. We have recently shown increased levels of lung adenosine inhibit alveolar fluid clearance, an important predictor of outcome in patients with ARDS. We hypothesized that alcohol might worsen lung injury by increasing lung adenosine levels, resulting in impaired active Na(+) transport in the lung. METHODS: We treated wild-type mice with alcohol administered i.p. to achieve blood alcohol levels associated with moderate to severe intoxication and measured the rate of alveolar fluid clearance and Na,K-ATPase expression in peripheral lung tissue and assessed the effect of alcohol on survival during exposure to hyperoxia. We used primary rat alveolar type II cells to investigate the mechanisms by which alcohol regulates alveolar Na(+) transport. RESULTS: Exposure to alcohol reduced alveolar fluid clearance, downregulated Na,K-ATPase in the lung tissue and worsened hyperoxia-induced lung injury. Alcohol caused an increase in BAL fluid adenosine levels. A similar increase in lung adenosine levels was observed after exposure to hyperoxia. In primary rat alveolar type II cells alcohol and adenosine decreased the abundance of the Na,K-ATPase at the basolateral membrane via a mechanism that required activation of the AMPK. CONCLUSIONS: Alcohol decreases alveolar fluid clearance and impairs survival from acute lung injury. Alcohol induced increases in lung adenosine levels may be responsible for reduction in alveolar fluid clearance and associated worsening of lung injury.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Etanol/toxicidade , Alvéolos Pulmonares/efeitos dos fármacos , Receptor A1 de Adenosina/metabolismo , Sódio/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/mortalidade , Adenosina/metabolismo , Animais , Western Blotting , Líquido da Lavagem Broncoalveolar/química , Células Cultivadas , Depressores do Sistema Nervoso Central/toxicidade , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Hiperóxia , Transporte de Íons/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/patologia , Edema Pulmonar/induzido quimicamente , Edema Pulmonar/metabolismo , Ratos , Ratos Sprague-Dawley , ATPase Trocadora de Sódio-Potássio/metabolismo , Análise de Sobrevida , Taxa de Sobrevida
8.
Thorax ; 67(2): 139-46, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21921091

RESUMO

BACKGROUND: The development of organ fibrosis after injury requires activation of transforming growth factor ß(1) which regulates the transcription of profibrotic genes. The systemic administration of a proteasomal inhibitor has been reported to prevent the development of fibrosis in the liver, kidney and bone marrow. It is hypothesised that proteasomal inhibition would prevent lung and skin fibrosis after injury by inhibiting TGF-ß(1)-mediated transcription. METHODS: Bortezomib, a small molecule proteasome inhibitor in widespread clinical use, was administered to mice beginning 7 days after the intratracheal or intradermal administration of bleomycin and lung and skin fibrosis was measured after 21 or 40 days, respectively. To examine the mechanism of this protection, bortezomib was administered to primary normal lung fibroblasts and primary lung and skin fibroblasts obtained from patients with idiopathic pulmonary fibrosis and scleroderma, respectively. RESULTS: Bortezomib promoted normal repair and prevented lung and skin fibrosis when administered beginning 7 days after the initiation of bleomycin. In primary human lung fibroblasts from normal individuals and patients with idiopathic pulmonary fibrosis and in skin fibroblasts from a patient with scleroderma, bortezomib inhibited TGF-ß(1)-mediated target gene expression by inhibiting transcription induced by activated Smads. An increase in the abundance and activity of the nuclear hormone receptor PPARγ, a repressor of Smad-mediated transcription, contributed to this response. CONCLUSIONS: Proteasomal inhibition prevents lung and skin fibrosis after injury in part by increasing the abundance and activity of PPARγ. Proteasomal inhibition may offer a novel therapeutic alternative in patients with dysregulated tissue repair and fibrosis.


Assuntos
Ácidos Borônicos/uso terapêutico , Inibidores de Proteassoma , Fibrose Pulmonar/prevenção & controle , Pirazinas/uso terapêutico , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Animais , Comunicação Autócrina/efeitos dos fármacos , Bleomicina , Ácidos Borônicos/farmacologia , Bortezomib , Células Cultivadas , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibrose , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , PPAR gama/metabolismo , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Pirazinas/farmacologia , Escleroderma Sistêmico/patologia , Transdução de Sinais/efeitos dos fármacos , Pele/patologia , Fator de Crescimento Transformador beta1/metabolismo
9.
Nano Lett ; 11(12): 5201-7, 2011 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-22023654

RESUMO

To facilitate the proposed use of graphene and its derivative graphene oxide (GO) in widespread applications, we explored strategies that improve the biocompatibility of graphene nanomaterials in the lung. In particular, solutions of aggregated graphene, Pluronic dispersed graphene, and GO were administered directly into the lungs of mice. The introduction of GO resulted in severe and persistent lung injury. Furthermore, in cells GO increased the rate of mitochondrial respiration and the generation of reactive oxygen species, activating inflammatory and apoptotic pathways. In contrast, this toxicity was significantly reduced in the case of pristine graphene after liquid phase exfoliation and was further minimized when the unoxidized graphene was well-dispersed with the block copolymer Pluronic. Our results demonstrate that the covalent oxidation of graphene is a major contributor to its pulmonary toxicity and suggest that dispersion of pristine graphene in Pluronic provides a pathway for the safe handling and potential biomedical application of two-dimensional carbon nanomaterials.


Assuntos
Materiais Biocompatíveis/metabolismo , Grafite/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Poloxâmero/metabolismo , Animais , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Grafite/administração & dosagem , Grafite/química , Grafite/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução , Poloxâmero/administração & dosagem , Poloxâmero/química , Poloxâmero/toxicidade , Espécies Reativas de Oxigênio/metabolismo
10.
J Cell Sci ; 124(Pt 17): 2927-37, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21878500

RESUMO

Laminins are heterotrimeric glycoproteins of the extracellular matrix that are secreted by epithelial cells and which are crucial for the normal structure and function of the basement membrane. We have generated a mouse harboring a conditional knockout of α3 laminin (Lama3(fl/fl)), one of the main laminin subunits in the lung basement membrane. At 60 days after intratracheal treatment of adult Lama3(fl/fl) mice with an adenovirus encoding Cre recombinase (Ad-Cre), the protein abundance of α3 laminin in whole lung homogenates was more than 50% lower than that in control-treated mice, suggesting a relatively long half-life for the protein in the lung. Upon exposure to an injurious ventilation strategy (tidal volume of 35 ml per kg of body weight for 2 hours), the mice with a knockdown of the α3 laminin subunit had less severe injury, as shown by lung mechanics, histology, alveolar capillary permeability and survival when compared with Ad-Null-treated mice. Knockdown of the α3 laminin subunit resulted in evidence of lung inflammation. However, this did not account for their resistance to mechanical ventilation. Rather, the loss of α3 laminin was associated with a significant increase in the collagen content of the lungs. We conclude that the loss of α3 laminin in the alveolar epithelium results in an increase in lung collagen, which confers resistance to mechanical injury.


Assuntos
Laminina/deficiência , Pulmão/fisiologia , Lesão Pulmonar Induzida por Ventilação Mecânica/prevenção & controle , Adenoviridae/genética , Animais , Colágeno Tipo I/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Epiteliais/fisiologia , Técnicas de Silenciamento de Genes , Humanos , Laminina/química , Laminina/genética , Laminina/metabolismo , Pulmão/citologia , Pulmão/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pneumonia/etiologia , Pneumonia/metabolismo , Pneumonia/patologia , Respiração com Pressão Positiva , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/patologia , Alvéolos Pulmonares/fisiologia , Lesão Pulmonar Induzida por Ventilação Mecânica/genética , Lesão Pulmonar Induzida por Ventilação Mecânica/metabolismo , Lesão Pulmonar Induzida por Ventilação Mecânica/patologia
11.
Part Fibre Toxicol ; 8: 19, 2011 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-21658250

RESUMO

BACKGROUND: Exposure to particulate matter (PM) air pollution may be an important environmental factor leading to exacerbations of inflammatory illnesses in the GI tract. PM can gain access to the gastrointestinal (GI) tract via swallowing of air or secretions from the upper airways or mucociliary clearance of inhaled particles. METHODS: We measured PM-induced cell death and mitochondrial ROS generation in Caco-2 cells stably expressing oxidant sensitive GFP localized to mitochondria in the absence or presence of an antioxidant. C57BL/6 mice were exposed to a very high dose of urban PM from Washington, DC (200 µg/mouse) or saline via gastric gavage and small bowel and colonic tissue were harvested for histologic evaluation, and RNA isolation up to 48 hours. Permeability to 4 kD dextran was measured at 48 hours. RESULTS: PM induced mitochondrial ROS generation and cell death in Caco-2 cells. PM also caused oxidant-dependent NF-κB activation, disruption of tight junctions and increased permeability of Caco-2 monolayers. Mice exposed to PM had increased intestinal permeability compared with PBS treated mice. In the small bowel, colocalization of the tight junction protein, ZO-1 was lower in the PM treated animals. In the small bowel and colon, PM exposed mice had higher levels of IL-6 mRNA and reduced levels of ZO-1 mRNA. Increased apoptosis was observed in the colon of PM exposed mice. CONCLUSIONS: Exposure to high doses of urban PM causes oxidant dependent GI epithelial cell death, disruption of tight junction proteins, inflammation and increased permeability in the gut in vitro and in vivo. These PM-induced changes may contribute to exacerbations of inflammatory disorders of the gut.


Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Oxidantes/farmacologia , Material Particulado/farmacologia , Poluição do Ar , Animais , Células CACO-2/citologia , Células CACO-2/efeitos dos fármacos , Células CACO-2/fisiologia , Morte Celular/efeitos dos fármacos , District of Columbia , Impedância Elétrica , Trato Gastrointestinal/citologia , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Ocludina , Tamanho da Partícula , Material Particulado/administração & dosagem , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Junções Íntimas/metabolismo , Junções Íntimas/ultraestrutura , Proteína da Zônula de Oclusão-1
12.
PLoS One ; 6(4): e18525, 2011 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-21494547

RESUMO

BACKGROUND: Exposure of human populations to ambient particulate matter (PM) air pollution significantly contributes to the mortality attributable to ischemic cardiovascular events. We reported that mice treated with intratracheally instilled PM develop a prothrombotic state that requires the release of IL-6 by alveolar macrophages. We sought to determine whether exposure of mice to PM increases the levels of PAI-1, a major regulator of thrombolysis, via a similar or distinct mechanism. METHODS AND PRINCIPAL FINDINGS: Adult, male C57BL/6 and IL-6 knock out (IL-6(-/-)) mice were exposed to either concentrated ambient PM less than 2.5 µm (CAPs) or filtered air 8 hours daily for 3 days or were exposed to either urban particulate matter or PBS via intratracheal instillation and examined 24 hours later. Exposure to CAPs or urban PM resulted in the IL-6 dependent activation of coagulation in the lung and systemically. PAI-1 mRNA and protein levels were higher in the lung and adipose tissue of mice treated with CAPs or PM compared with filtered air or PBS controls. The increase in PAI-1 was similar in wild-type and IL-6(-/-) mice but was absent in mice treated with etanercept, a TNF-α inhibitor. Treatment with etanercept did not prevent the PM-induced tendency toward thrombus formation. CONCLUSIONS: Mice exposed to inhaled PM exhibited a TNF-α-dependent increase in PAI-1 and an IL-6-dependent activation of coagulation. These results suggest that multiple mechanisms link PM-induced lung inflammation with the development of a prothrombotic state.


Assuntos
Coagulação Sanguínea/fisiologia , Material Particulado/efeitos adversos , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Pneumonia/sangue , Pneumonia/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Linhagem Celular Tumoral , Cidades , Fibrina/metabolismo , Humanos , Exposição por Inalação , Interleucina-6 , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Tamanho da Partícula , Inibidor 1 de Ativador de Plasminogênio/genética , Pneumonia/patologia , Transcrição Gênica , Fator de Necrose Tumoral alfa/metabolismo
13.
Am J Respir Crit Care Med ; 183(11): 1490-8, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21317313

RESUMO

RATIONALE: Diabetic patients have a lower incidence of acute respiratory distress syndrome (ARDS), and those who develop ARDS are less likely to die. The mechanisms that underlie this protection are unknown. OBJECTIVES: To determine whether leptin resistance, a feature of diabetes, prevents fibroproliferation after lung injury. METHODS: We examined lung injury and fibroproliferation after the intratracheal instillation of bleomycin in wild-type and leptin-resistant (db/db) diabetic mice. We examined the effect of leptin on transforming growth factor (TGF)-ß(1)-mediated transcription in primary normal human lung fibroblasts. Bronchoalveolar lavage fluid (BAL) samples from patients with ARDS and ventilated control subjects were obtained for measurement of leptin and active TGF-ß(1) levels. MEASUREMENTS AND MAIN RESULTS: Diabetic mice (db/db) were resistant to lung fibrosis. The db/db mice had higher levels of peroxisome proliferator-activated receptor-γ (PPARγ), an inhibitor of the transcriptional response to TGF-ß(1), a cytokine critical in the pathogenesis of fibroproliferative ARDS. In normal human lung fibroblasts, leptin augmented the transcription of profibrotic genes in response to TGF-ß(1) through a mechanism that required PPARγ. In patients with ARDS, BAL leptin levels were elevated and correlated with TGF-ß(1) levels. Overall, there was no significant relationship between BAL leptin levels and clinical outcomes; however, in nonobese patients, higher BAL leptin levels were associated with fewer intensive care unit- and ventilator-free days and higher mortality. CONCLUSIONS: Leptin signaling is required for bleomycin-induced lung fibrosis. Leptin augments TGF-ß(1) signaling in lung fibroblasts by inhibiting PPARγ. These findings provide a mechanism for the observed protection against ARDS observed in diabetic patients.


Assuntos
Leptina/metabolismo , Leptina/farmacologia , PPAR gama/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Animais , Líquido da Lavagem Broncoalveolar , Modelos Animais de Doenças , Feminino , Humanos , Pulmão/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , Fator de Crescimento Transformador beta/metabolismo
14.
Am J Respir Crit Care Med ; 183(8): 1043-54, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20959557

RESUMO

RATIONALE: Acute lung injury and the acute respiratory distress syndrome are characterized by increased lung oxidant stress and apoptotic cell death. The contribution of epithelial cell apoptosis to the development of lung injury is unknown. OBJECTIVES: To determine whether oxidant-mediated activation of the intrinsic or extrinsic apoptotic pathway contributes to the development of acute lung injury. METHODS: Exposure of tissue-specific or global knockout mice or cells lacking critical components of the apoptotic pathway to hyperoxia, a well-established mouse model of oxidant-induced lung injury, for measurement of cell death, lung injury, and survival. MEASUREMENTS AND MAIN RESULTS: We found that the overexpression of SOD2 prevents hyperoxia-induced BAX activation and cell death in primary alveolar epithelial cells and prolongs the survival of mice exposed to hyperoxia. The conditional loss of BAX and BAK in the lung epithelium prevented hyperoxia-induced cell death in alveolar epithelial cells, ameliorated hyperoxia-induced lung injury, and prolonged survival in mice. By contrast, Cyclophilin D-deficient mice were not protected from hyperoxia, indicating that opening of the mitochondrial permeability transition pore is dispensable for hyperoxia-induced lung injury. Mice globally deficient in the BH3-only proteins BIM, BID, PUMA, or NOXA, which are proximal upstream regulators of BAX and BAK, were not protected against hyperoxia-induced lung injury suggesting redundancy of these proteins in the activation of BAX or BAK. CONCLUSIONS: Mitochondrial oxidant generation initiates BAX- or BAK-dependent alveolar epithelial cell death, which contributes to hyperoxia-induced lung injury.


Assuntos
Lesão Pulmonar Aguda/etiologia , Mucosa Respiratória/fisiopatologia , Animais , Apoptose/fisiologia , Peptidil-Prolil Isomerase F , Ciclofilinas/fisiologia , Modelos Animais de Doenças , Hiperóxia/complicações , Hiperóxia/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Estresse Oxidativo/fisiologia , Alvéolos Pulmonares/química , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/fisiopatologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/análise , Mucosa Respiratória/metabolismo , Superóxido Dismutase/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismo
15.
Invest Clin ; 51(1): 53-63, 2010 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-20815156

RESUMO

Ischemia-reperfusion (IR) lung injury is a significant cause of morbidity and mortality in certain clinical scenarios that include transplantation, thromboendarterectomy and reexpansion injury of the lung. Edema of the contralateral lung after IR injury of one lung has been reported and this study was aimed to clarify the pathophysiology of this phenomenon. One-lung ischemia/hypoxia followed by reperfusion with either blood or an acellular plasma substitute was achieved in an isolated rabbit lung model by hilum clamping. After reperfusion, we studied the isolated effects of vasoconstriction and inflammation on contralateral lung injury by using papaverine or hydrocortisone as vasodilator and anti-inflammatory, respectively. We observed that IR of one lung induces edema of the contralateral lung. Absence of leukocytes and platelets in the perfusate or use of hydrocortisone completely inhibits IR injury. Moreover, papaverine suppresses edema of the contralateral, but not that of the reperfused lung. We concluded that IR of one lung produces edema in the contralateral lung that requires vasoconstriction of the latter.


Assuntos
Pulmão/irrigação sanguínea , Edema Pulmonar/etiologia , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/fisiopatologia , Vasoconstrição , Animais , Feminino , Técnicas In Vitro , Coelhos
16.
Nano Lett ; 10(5): 1664-70, 2010 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-20377197

RESUMO

Excitement surrounding the attractive physical and chemical characteristics of single walled carbon nanotubes (SWCNTs) has been tempered by concerns regarding their potential health risks. Here we consider the lung toxicity of nanoscale dispersed SWCNTs (mean diameter approximately 1 nm). Because dispersion of the SWCNTs increases their aspect ratio relative to as-produced aggregates, we directly test the prevailing hypothesis that lung toxicity associated with SWCNTs compared with other carbon structures is attributable to the large aspect ratio of the individual particles. Thirty days after their intratracheal administration to mice, the granuloma-like structures with mild fibrosis in the large airways observed in mice treated with aggregated SWCNTs were absent in mice treated with nanoscale dispersed SWCNTs. Examination of lung sections from mice treated with nanoscale dispersed SWCNTs revealed uptake of the SWCNTs by macrophages and gradual clearance over time. We conclude that the toxicity of SWCNTs in vivo is attributable to aggregation of the nanomaterial rather than the large aspect ratio of the individual nanotubes. Biocompatible nanoscale dispersion provides a scalable method to generate purified preparations of SWCNTs with minimal toxicity, thus allowing them to be used safely in commercial and biomedical applications.


Assuntos
Materiais Biocompatíveis/toxicidade , Nanotubos/química , Nanotubos/toxicidade , Traqueia/efeitos dos fármacos , Traqueia/patologia , Traqueíte/induzido quimicamente , Traqueíte/patologia , Animais , Coloides/química , Coloides/toxicidade , Cristalização/métodos , Teste de Materiais , Camundongos , Camundongos Endogâmicos C57BL , Nanotubos/ultraestrutura , Tamanho da Partícula
17.
Invest. clín ; 51(1): 53-63, Mar. 2010. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-574083

RESUMO

El daño pulmonar por isquemia-reperfusión (IR) es una importante causa de morbilidad y mortalidad en ciertas condiciones clínicas que incluyen trasplantes, tromboendarterectomía y daño pulmonar por reexpansión. El edema pulmonar contralateral posterior al daño por IR de un pulmón ha sido reportado y esta investigación tiene como objetivo esclarecer la fisiopatología de dicho fenómeno. En un modelo de pulmones aislados y perfundidos de conejo, fue ocluido el hilio pulmonar de forma unilateral induciendo isquemia/hipoxia de dicho órgano, seguido de reperfusiones con sangre o con un substituto plasmático acelular. Los efectos aislados de vasoconstricción e inflamación en el daño pulmonar contralateral fueron estudiados posterior a la reperfusión, usando papaverina e hidrocortisona como agente vasodilatador y antiinflamatorio, respectivamente. En esta investigación se observó que la IR de un pulmón induce edema en el pulmón contralateral. La ausencia de leucocitos y plaquetas en la perfusión y el uso de hidrocortisona inhibió por completo el daño por IR. La papaverina suprimió el edema en el pulmón contralateral mas no en el reperfundido. Se concluye que la IR de un pulmón produce edema en el pulmón contralateral, para lo cual se requiere la presencia de vasoconstricción.


Ischemia-reperfusion (IR) lung injury is a significant cause of morbidity and mortality in certain clinical scenarios that include transplantation, thromboendarterectomy and reexpansion injury of the lung. Edema of the contralateral lung after IR injury of one lung has been reported and this study was aimed to clarify the pathophysiology of this phenomenon. One-lung ischemia/hypoxia followed by reperfusion with either blood or an acellular plasma substitute was achieved in an isolated rabbit lung model by hilum clamping. After reperfusion, we studied the isolated effects of vasoconstriction and inflammation on contralateral lung injury by using papaverine or hydrocortisone as vasodilator and anti-inflammatory, respectively. We observed that IR of one lung induces edema of the contralateral lung. Absence of leukocytes and platelets in the perfusate or use of hydrocortisone completely inhibits IR injury. Moreover, papaverine suppresses edema of the contralateral, but not that of the reperfused lung. We concluded that IR of one lung produces edema in the contralateral lung that requires vasoconstriction of the latter.


Assuntos
Animais , Coelhos , Edema Pulmonar/patologia , Isquemia/complicações , Traumatismo por Reperfusão , Vasoconstrição , Animais de Laboratório , Pneumopatias
18.
FASEB J ; 23(7): 2055-64, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19237507

RESUMO

Elevated ambient levels of particulate matter air pollution are associated with excess daily mortality, largely attributable to increased rates of cardiovascular events. We have previously reported that particulate matter induces p53-dependent apoptosis in primary human alveolar epithelial cells. Activation of the intrinsic apoptotic pathway by p53 often requires the transcription of the proapoptotic Bcl-2 proteins Noxa, Puma, or both. In this study, we exposed alveolar epithelial cells in culture and mice to fine particulate matter <2.5 microm in diameter (PM(2.5)) collected from the ambient air in Washington, D. C. Exposure to PM(2.5) induced apoptosis in primary alveolar epithelial cells from wild-type but not Noxa(-/-) mice. Twenty-four hours after the intratracheal instillation of PM(2.5), wild-type mice showed increased apoptosis in the lung and increased levels of mRNA encoding Noxa but not Puma. These changes were associated with increased permeability of the alveolar-capillary membrane and inflammation. All of these findings were absent or attenuated in Noxa(-/-) animals. We conclude that PM(2.5)-induced cell death requires Noxa both in vitro and in vivo and that Noxa-dependent cell death might contribute to PM-induced alveolar epithelial dysfunction and the resulting inflammatory response.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Inflamação/induzido quimicamente , Pneumopatias/patologia , Material Particulado/efeitos adversos , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Animais , Proteínas Reguladoras de Apoptose/fisiologia , Morte Celular , Camundongos , Camundongos Knockout , Tamanho da Partícula , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Mensageiro/análise , Proteínas Supressoras de Tumor/análise , Regulação para Cima
19.
J Biol Chem ; 284(4): 2176-86, 2009 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-19033436

RESUMO

We have previously reported that airborne particulate matter air pollution (PM) activates the intrinsic apoptotic pathway in alveolar epithelial cells through a pathway that requires the mitochondrial generation of reactive oxygen species (ROS) and the activation of p53. We sought to examine the source of mitochondrial oxidant production and the molecular links between ROS generation and the activation of p53 in response to PM exposure. Using a mitochondrially targeted ratiometric sensor (Ro-GFP) in cells lacking mitochondrial DNA (rho0 cells) and cells stably expressing a small hairpin RNA directed against the Rieske iron-sulfur protein, we show that site III of the mitochondrial electron transport chain is primarily responsible for fine PM (PM2.5)-induced oxidant production. In alveolar epithelial cells, the overexpression of SOD1 prevented the PM2.5-induced ROS generation from the mitochondria and prevented cell death. Infection of mice with an adenovirus encoding SOD1 prevented the PM2.5-induced death of alveolar epithelial cells and the associated increase in alveolar-capillary permeability. Treatment with PM2.5 resulted in the ROS-mediated activation of the oxidant-sensitive kinase ASK1 and its downstream kinase JNK. Murine embryonic fibroblasts from ASK1 knock-out mice, alveolar epithelial cells transfected with dominant negative constructs against ASK1, and pharmacologic inhibition of JNK with SP600125 (25 microM) prevented the PM2.5-induced phosphorylation of p53 and cell death. We conclude that particulate matter air pollution induces the generation of ROS primarily from site III of the mitochondrial electron transport chain and that these ROS activate the intrinsic apoptotic pathway through ASK1, JNK, and p53.


Assuntos
Poluentes Atmosféricos/farmacologia , Apoptose/efeitos dos fármacos , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Células Epiteliais/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Mitocôndrias/efeitos dos fármacos , Alvéolos Pulmonares/citologia , Animais , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/citologia , Células Epiteliais/enzimologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Masculino , Camundongos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Oxidantes/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1
20.
Invest Clin ; 49(2): 181-93, 2008 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-18717265

RESUMO

Hypocapnia/alkalosis is a consequence of several lung and metabolic pathologies. The aim of this study was to determine whether the increase of fluid filtration rate (FFR) that occurs during Hypocapnia/alkalosis circumstances is determined by hypocapnia, alkalosis or both. 7 groups were formed (N=36) using isolated rabbit lungs. Group 1: Control (PCO2 6%, pH: 7.35-7.45); Group 2 (n=6): Hypocapnia/Alkalosis (CO2 1%, pH: 7.9); Group 3 (n=6): Hypocapnia/Normo-pH (CO2 1% pH 7.35-7.45), Group 4 (n=6) Normocapnia/Alcalosis (CO2 6%, pH: 7.9). Fenoterol, papaverine and hydrocortisone were added to Groups 5, 6 and 7 (n=4) respectively, all under Normocapnia/Alkalosis. FFR and Pulmonary Arterial Pressure (Pap) were considerably higher in group 2 than in control (FFR: 1.92g/min +/- 0.6 vs 0.0 g/min +/- 0.006). A strong influence exerted by pH was observed when Group 3 and group 4 were compared (FFR: 0.02 g/min +/- 0.009 vs 2.3 g/min +/- 0.9) and (Pap: 13.5 cmH2O +/- 1.4 vs 90 cmH2O +/- 15). A reduced effect was observed in groups 5 and 6 (papaverine and hydrocorisone) and a totally abolished effect was observed in group 7 (fenoterol) (FFR: 0.001 +/- 0.0003 mL/min and Pap: 14 +/- 0.8 cmH2O). Pulmonary edema induced by Hypocapnia/alkalosis is a consequence of alkalosis and not of hypocapnia. This effect could be due to inflammatory damage in the lung parenchyma and alkalosis-mediated vasoconstriction.


Assuntos
Alcalose/fisiopatologia , Deslocamentos de Líquidos Corporais/fisiologia , Hipocapnia/fisiopatologia , Pulmão/fisiopatologia , Edema Pulmonar/fisiopatologia , Agonistas Adrenérgicos beta/farmacologia , Alcalose/complicações , Animais , Anti-Inflamatórios/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Fenoterol/farmacologia , Deslocamentos de Líquidos Corporais/efeitos dos fármacos , Hidrocortisona/farmacologia , Concentração de Íons de Hidrogênio , Hipocapnia/complicações , Pulmão/irrigação sanguínea , Pulmão/efeitos dos fármacos , Papaverina/farmacologia , Perfusão , Artéria Pulmonar , Edema Pulmonar/etiologia , Coelhos , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatadores/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...