RESUMEN
Acute ethanol intoxication increases the risk of sepsis and aggravates the symptoms of sepsis and lung injury. Therefore, this study aimed to explore whether sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P)/S1P receptor 1 (S1PR1) signaling pathway functions in lung injury caused by acute ethanol intoxication-enhanced sepsis, as well as its underlying mechanism. The acute ethanol intoxication model was simulated by intraperitoneally administering mice with 32% ethanol solution, and cecal ligation and puncture (CLP) was used to construct the sepsis model. The lung tissue damage was observed by hematoxylin-eosin (H&E) staining, and the wet-to-dry (W/D) ratio was used to evaluate the degree of pulmonary edema. Inflammatory cell counting and protein concentration in bronchoalveolar lavage fluid (BALF) were, respectively, detected by hemocytometer and bicinchoninic acid (BCA) method. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß, and IL-18 in BALF were detected by their commercial enzyme-linked immunosorbent assay (ELISA) kits. The myeloperoxidase (MPO) activity and expression of apoptosis-related proteins and SphK1/S1P/S1PR1 pathway-related proteins were, respectively, analyzed by MPO ELISA kit and Western blot analysis. The cell apoptosis in lung tissues was observed by TUNEL assay. Acute ethanol intoxication (EtOH) decreased the survival rate of mice and exacerbated the lung injury caused by sepsis through increasing pulmonary vascular permeability, neutrophil infiltration, release of inflammatory factors, and cell apoptosis. In addition, EtOH could activate the SphK1/S1P/S1PR1 pathway in CLP mice. However, PF-543, as a specific inhibitor of SphK1, could partially reverse the deleterious effects on lung injury of CLP mice. PF-543 alleviated lung injury caused by sepsis in acute ethanol intoxication rats by suppressing the SphK1/S1P/S1PR1 signaling pathway.
Asunto(s)
Intoxicación Alcohólica/complicaciones , Inhibidores Enzimáticos/farmacología , Lesión Pulmonar/prevención & control , Pulmón/efectos de los fármacos , Lisofosfolípidos/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Pirrolidinas/farmacología , Sepsis/tratamiento farmacológico , Receptores de Esfingosina-1-Fosfato/metabolismo , Esfingosina/análogos & derivados , Sulfonas/farmacología , Animales , Apoptosis/efectos de los fármacos , Citocinas/metabolismo , Modelos Animales de Enfermedad , Mediadores de Inflamación/metabolismo , Pulmón/enzimología , Pulmón/patología , Lesión Pulmonar/enzimología , Lesión Pulmonar/etiología , Lesión Pulmonar/patología , Masculino , Metanol/farmacología , Ratones Endogámicos C57BL , Infiltración Neutrófila/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Neumonía/enzimología , Neumonía/etiología , Neumonía/patología , Neumonía/prevención & control , Edema Pulmonar/enzimología , Edema Pulmonar/etiología , Edema Pulmonar/patología , Edema Pulmonar/prevención & control , Sepsis/complicaciones , Sepsis/enzimología , Transducción de Señal , Esfingosina/metabolismoRESUMEN
High-altitude (HA, >2500 m) hypoxic exposure evokes several physiological processes that may be abetted by differential genetic distribution in sojourners, who are susceptible to various HA disorders, such as high-altitude pulmonary edema (HAPE). The genetic variants in hypoxia-sensing genes influence the transcriptional output; however the functional role has not been investigated in HAPE. This study explored the two hypoxia-sensing genes, prolyl hydroxylase domain protein 2 (EGLN1) and factor inhibiting HIF-1α (HIF1AN) in HA adaptation and maladaptation in three well-characterized groups: highland natives, HAPE-free controls and HAPE-patients. The two genes were sequenced and subsequently validated through genotyping of significant single nucleotide polymorphisms (SNPs), haplotyping and multifactor dimensionality reduction. Three EGLN1 SNPs rs1538664, rs479200 and rs480902 and their haplotypes emerged significant in HAPE. Blood gene expression and protein levels also differed significantly (P < 0.05) and correlated with clinical parameters and respective alleles. The RegulomeDB annotation exercises of the loci corroborated regulatory role. Allele-specific differential expression was evidenced by luciferase assay followed by electrophoretic mobility shift assay, liquid chromatography with tandem mass spectrometry and supershift assays, which confirmed allele-specific transcription factor (TF) binding of FUS RNA-binding protein (FUS) with rs1538664A, Rho GDP dissociation inhibitor 1 (ARHDGIA) with rs479200T and hypoxia upregulated protein 1 (HYOU1) with rs480902C. Docking simulation studies were in sync for the DNA-TF structural variations. There was strong networking among the TFs that revealed physiological consequences through relevant pathways. The two hydroxylases appear crucial in the regulation of hypoxia-inducible responses.
Asunto(s)
Mal de Altura , Sitios Genéticos , Hipertensión Pulmonar , Prolina Dioxigenasas del Factor Inducible por Hipoxia , Oxigenasas de Función Mixta , Polimorfismo de Nucleótido Simple , Edema Pulmonar , Proteínas Represoras , Células A549 , Altitud , Mal de Altura/enzimología , Mal de Altura/genética , Femenino , Regulación Enzimológica de la Expresión Génica , Humanos , Hipertensión Pulmonar/enzimología , Hipertensión Pulmonar/genética , Prolina Dioxigenasas del Factor Inducible por Hipoxia/biosíntesis , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Masculino , Oxigenasas de Función Mixta/biosíntesis , Oxigenasas de Función Mixta/genética , Edema Pulmonar/enzimología , Edema Pulmonar/genética , Proteínas Represoras/biosíntesis , Proteínas Represoras/genética , Factores de RiesgoRESUMEN
The present study aims to reveal the molecular mechanism of peroxisome proliferator-activated receptor γ (PPARγ) on sepsis-induced acute lung injury (ALI). To do that, the rat injury model was established using cecal ligation and perforation (CLP) method, followed by different treatments, and the rats were divided into Sham group, CLP group, CLP + rosiglitazone (PPARγ agonist) group, CLP + GW9662 (PPARγ inhibitor) group, CLP + bpV (phosphatase and tensin homolog (PTEN) inhibitor) group, CLP + GW9662 + bpV group. Compared with Sham group, the mRNA and protein expression levels of PPARγ were down-regulated, the inflammation levels were elevated, and the apoptosis was increased in CLP group. After treatment with rosiglitazone, the protein expression level of PPARγ was significantly up-regulated, the phosphorylation level of PTEN/ß-catenin pathway was decreased, the PTEN/ß-catenin pathway was inhibited, the lung injury, inflammation and apoptosis were reduced. The opposite effect was observed after treatment with GW9662. Besides, bpV inhibited PTEN/ß-catenin pathway, and relieved the lung tissue injury. The overexpression of PPARγ reduced inflammatory response and inhibited apoptosis in sepsis-induced ALI. Furthermore, PPARγ relieved the sepsis-induced ALI by inhibiting the PTEN/ß-catenin pathway.
Asunto(s)
Lesión Pulmonar Aguda/prevención & control , Pulmón/efectos de los fármacos , PPAR gamma/agonistas , Fosfohidrolasa PTEN/metabolismo , Rosiglitazona/farmacología , Sepsis/tratamiento farmacológico , beta Catenina/metabolismo , Lesión Pulmonar Aguda/enzimología , Lesión Pulmonar Aguda/microbiología , Lesión Pulmonar Aguda/patología , Anilidas/farmacología , Animales , Apoptosis/efectos de los fármacos , Modelos Animales de Enfermedad , Pulmón/enzimología , Pulmón/microbiología , Pulmón/patología , Masculino , PPAR gamma/antagonistas & inhibidores , PPAR gamma/genética , PPAR gamma/metabolismo , Fosforilación , Neumonía/enzimología , Neumonía/microbiología , Neumonía/prevención & control , Edema Pulmonar/enzimología , Edema Pulmonar/microbiología , Edema Pulmonar/prevención & control , Ratas Sprague-Dawley , Sepsis/enzimología , Sepsis/microbiología , Transducción de SeñalRESUMEN
OBJECTIVE: The purpose of the study was to investigate the association between angiotensin-converting enzyme gene insertion/deletion polymorphism and high-altitude pulmonary edema. METHODS: A systematic search for relevant literature was performed in MEDLINE, CNKI, and EMBASE. The pooled odds ratios and their corresponding 95% confidence intervals were calculated in STATA 12.0 software. RESULTS: Seven studies, with a total of 304 patients and 564 controls, qualified for the inclusion in the analysis. There was no significant association between angiotensin-converting enzyme insertion/deletion polymorphism and high-altitude pulmonary edema risk in the total population (DD vs II: odds ratio=1.07, 95% confidence interval 0.52-2.24; DI vs II: odds ratio=1.12, 0.85-1.49; dominant model: odds ratio=1.07, 0.83-1.40; recessive model: odds ratio=0.96, 0.53-1.77). Subgroup analysis according to race also revealed no significant correlation between angiotensin-converting enzyme gene insertion/deletion polymorphism and high-altitude pulmonary edema. CONCLUSIONS: Our findings suggest that angiotensin-converting enzyme insertion/deletion polymorphism does not contribute to the risk of high-altitude pulmonary edema. Larger, well-designed studies are required to further validate these results.
Asunto(s)
Altitud , Mutación INDEL/genética , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Edema Pulmonar/enzimología , Edema Pulmonar/genética , Intervalos de Confianza , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Oportunidad Relativa , Sesgo de PublicaciónRESUMEN
Background Systemic innate immune priming is a recognized sequela of post-ischemic neuroinflammation and contributor to delayed neurodegeneration. Given mounting evidence linking acute stroke with reactive lung inflammation, we asked whether enhanced expression of the endogenous antioxidant extracellular superoxide dismutase 3 (SOD3) produced by alveolar type II pneumocytes would protect the lung from transient global cerebral ischemia and the brain from the delayed effects of ischemia-reperfusion. Methods and Results Following 15 minutes of global cerebral ischemia or sham conditions, transgenic SOD3 and wild-type mice were followed daily for changes in weight, core temperature, and neurological function. Three days after reperfusion, arterial and venous samples were collected for complete blood counts, flow cytometry, and SOD3 protein blotting, and immunohistochemistry was performed on lung and brain tissue to assess tissue injury, blood-brain barrier permeability, and neutrophil transmigration. Relative to ischemic controls, transgenic SOD3 mice performed better on functional testing and exhibited reduced peripheral neutrophil activation, lung inflammation, and blood-brain barrier leak. Once released from the lung, SOD3 was predominantly not cell associated and depleted in the venous phase of circulation. Conclusions In addition to reducing the local inflammatory response to cerebral ischemia, targeted enrichment of SOD3 within the lung confers distal neuroprotection against ischemia-reperfusion injury. These data suggest that therapies geared toward enhancing adaptive lung-neurovascular coupling may improve outcomes following acute stroke and cardiac arrest.
Asunto(s)
Isquemia Encefálica/enzimología , Encéfalo/enzimología , Pulmón/enzimología , Acoplamiento Neurovascular , Neumonía/prevención & control , Daño por Reperfusión/prevención & control , Superóxido Dismutasa/metabolismo , Animales , Barrera Hematoencefálica/enzimología , Barrera Hematoencefálica/inmunología , Barrera Hematoencefálica/patología , Encéfalo/inmunología , Encéfalo/patología , Edema Encefálico/enzimología , Edema Encefálico/patología , Edema Encefálico/prevención & control , Isquemia Encefálica/inmunología , Isquemia Encefálica/patología , Permeabilidad Capilar , Modelos Animales de Enfermedad , Humanos , Inmunidad Innata , Pulmón/inmunología , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Infiltración Neutrófila , Neumonía/enzimología , Neumonía/inmunología , Neumonía/patología , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Edema Pulmonar/prevención & control , Daño por Reperfusión/enzimología , Daño por Reperfusión/inmunología , Daño por Reperfusión/patología , Superóxido Dismutasa/genéticaRESUMEN
Pulmonary edema is the major factor of tissue hypoxia in acute lung injury. Disruption of cell-cell contacts and lung interstitium increases permeability of the vascular endothelium and alveolar epithelium, which leads to the development of pulmonary edema. Meprin metalloproteases cleave extracellular matrix proteins, thus aggravating pulmonary edema. Meprin inhibitor actinonin was administered to rats with LPS-induced acute lung injury. Damaged lungs looked spotted and had multiple hemorrhage focuses, protein concentration in lavage fluid was increased, and lung weight coefficient was high. Administration of meprin inhibitor actinonin considerably reduced protein content in the bronchoalvelolar lavage and lung coefficient; only solitary lung hemorrhages were seen after this treatment. Thus, inhibition of meprins potentially alleviates LPS-induced disorders in the lung tissue permeability and reduces pulmonary edema.
Asunto(s)
Lesión Pulmonar Aguda/tratamiento farmacológico , Antiinflamatorios/farmacología , Edema Pulmonar/tratamiento farmacológico , Tiopronina/antagonistas & inhibidores , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/enzimología , Lesión Pulmonar Aguda/patología , Animales , Líquido del Lavado Bronquioalveolar/química , Ácidos Hidroxámicos/farmacología , Lipopolisacáridos/administración & dosificación , Pulmón/efectos de los fármacos , Pulmón/enzimología , Pulmón/patología , Masculino , Tamaño de los Órganos/efectos de los fármacos , Edema Pulmonar/inducido químicamente , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Ratas , Ratas Sprague-Dawley , Tiopronina/metabolismoRESUMEN
Klebsiella pneumoniae causes severe infections including pneumonia and sepsis and treatments are complicated by increased levels of antibiotic resistance. We have identified a flavonoid kaempferol-3-O-glucorhamnoside derived from the plant Thesium chinense Turcz that possessed potent anti-inflammatory effects in K. pneumoniae infected mice. Administration of kaempferol-3-O-glucorhamnoside before bacterial challenge effectively suppressed expression of the major inflammatory cytokines TNF-α, IL-6, IL-1ß and PGE2 and ameliorated lung edema. In addition, administration of this compound to cultured RAW macrophages or Balb/c mice resulted in the suppression of NFκB and MAP kinase phosphorylation indicating an inhibitory effect on inflammation in vitro and in vivo. Kaempferol-3-O-glucorhamnoside also decreased ROS levels and overall oxidative stress in lungs and in cultured cells generated by K. pneumoniae exposure. Taken together, kaempferol-3-O-glucorhamnoside is a potent anti-inflammatory in vitro and in vivo and is a promising therapeutic agent for treating K. pneumoniae infections in the clinic.
Asunto(s)
Antiinflamatorios/farmacología , Quempferoles/farmacología , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/patogenicidad , Pulmón/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Neumonía Bacteriana/tratamiento farmacológico , Animales , Antioxidantes/farmacología , Dinoprostona/metabolismo , Modelos Animales de Enfermedad , Interacciones Huésped-Patógeno , Mediadores de Inflamación/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Infecciones por Klebsiella/enzimología , Infecciones por Klebsiella/microbiología , Pulmón/enzimología , Pulmón/microbiología , Macrófagos/efectos de los fármacos , Macrófagos/enzimología , Macrófagos/microbiología , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Neumonía Bacteriana/enzimología , Neumonía Bacteriana/microbiología , Edema Pulmonar/enzimología , Edema Pulmonar/microbiología , Edema Pulmonar/prevención & control , Células RAW 264.7 , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Aims: Acute increases in left ventricular end diastolic pressure (LVEDP) can induce pulmonary edema (PE). The mechanism(s) for this rapid onset edema may involve more than just increased fluid filtration. Lung endothelial cell permeability is regulated by pressure-dependent activation of nitric oxide synthase (NOS). Herein, we demonstrate that pressure-dependent NOS activation contributes to vascular failure and PE in a model of acute heart failure (AHF) caused by hypertension.Methods and results: Male Sprague-Dawley rats were anesthetized and mechanically ventilated. Acute hypertension was induced by norepinephrine (NE) infusion and resulted in an increase in LVEDP and pulmonary artery pressure (Ppa) that were associated with a rapid fall in PaO2, and increases in lung wet/dry ratio and injury scores. Heart failure (HF) lungs showed increased nitrotyrosine content and ROS levels. L-NAME pretreatment mitigated the development of PE and reduced lung ROS concentrations to sham levels. Apocynin (Apo) pretreatment inhibited PE. Addition of tetrahydrobiopterin (BH4) to AHF rats lung lysates and pretreatment of AHF rats with folic acid (FA) prevented ROS production indicating endothelial NOS (eNOS) uncoupling.Conclusion: Pressure-dependent NOS activation leads to acute endothelial hyperpermeability and rapid PE by an increase in NO and ROS in a model of AHF. Acute increases in pulmonary vascular pressure, without NOS activation, was insufficient to cause significant PE. These results suggest a clinically relevant role of endothelial mechanotransduction in the pathogenesis of AHF and further highlights the concept of active barrier failure in AHF. Therapies targetting the prevention or reversal of endothelial hyperpermeability may be a novel therapeutic strategy in AHF.
Asunto(s)
Insuficiencia Cardíaca/enzimología , Hipertensión Pulmonar/enzimología , Mecanotransducción Celular , Óxido Nítrico Sintasa/genética , Edema Pulmonar/enzimología , Animales , Biopterinas/administración & dosificación , Biopterinas/análogos & derivados , Presión Sanguínea/efectos de los fármacos , Permeabilidad Capilar/efectos de los fármacos , Modelos Animales de Enfermedad , Células Endoteliales/enzimología , Células Endoteliales/patología , Ácido Fólico/administración & dosificación , Insuficiencia Cardíaca/fisiopatología , Humanos , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/patología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , NG-Nitroarginina Metil Éster/administración & dosificación , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/metabolismo , Norepinefrina/efectos adversos , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/patología , Edema Pulmonar/metabolismo , Edema Pulmonar/patología , Ratas , Especies Reactivas de Oxígeno/metabolismo , Tirosina/administración & dosificación , Tirosina/análogos & derivadosRESUMEN
The development of multiple organ failure in patients with hemorrhagic shock is significantly influenced by patient age. Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator of energy homeostasis, which coordinates metabolic repair during cellular stress. We investigated whether AMPK-regulated signaling pathways are age-dependent in hemorrhage-induced lung injury and whether AMPK activation by 5-amino-4-imidazole carboxamide riboside (AICAR) affords lung protective effects. Male C57/BL6 young mice (3-5 mo), mature adult mice (9-12 mo), and young AMPKα1 knockout mice (3-5 mo) were subjected to hemorrhagic shock by blood withdrawing, followed by resuscitation with shed blood and lactated Ringer's solution. Plasma proinflammatory cytokines were similarly elevated in C57/BL6 young and mature adult mice after hemorrhagic shock. However, mature adult mice exhibited more severe lung edema and neutrophil infiltration, and higher mitochondrial damage in alveolar epithelial type II cells, than did young mice. No change in autophagy was observed. At molecular analysis, the phosphorylation of the catalytic subunit AMPKα1 was associated with nuclear translocation of peroxisome proliferator-activated receptor γ co-activator-α in young, but not mature, adult mice. Treatment with AICAR ameliorated the disruption of lung architecture in mice of both ages; however, effects in mature adult mice were different than young mice and also involved inhibition of nuclear factor-κB. In young AMPKα1 knockout mice, AICAR failed to improve hypotension and lung neutrophil infiltration. Our data demonstrate that during hemorrhagic shock, AMPK-dependent metabolic repair mechanisms are important for mitigating lung injury. However, these mechanisms are less competent with age.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Envejecimiento/metabolismo , Pulmón/metabolismo , Pulmón/patología , Redes y Vías Metabólicas , Choque Hemorrágico/enzimología , Choque Hemorrágico/patología , Células Epiteliales Alveolares/metabolismo , Células Epiteliales Alveolares/patología , Células Epiteliales Alveolares/ultraestructura , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Autofagia/efectos de los fármacos , Western Blotting , Líquido del Lavado Bronquioalveolar , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Citocinas/sangre , Modelos Animales de Enfermedad , Activación Enzimática/efectos de los fármacos , Hipotensión/sangre , Hipotensión/complicaciones , Hipotensión/enzimología , Hipotensión/patología , Masculino , Redes y Vías Metabólicas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , FN-kappa B/metabolismo , Infiltración Neutrófila/efectos de los fármacos , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Fosforilación/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Edema Pulmonar/complicaciones , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Ribonucleótidos/farmacología , Choque Hemorrágico/sangre , Choque Hemorrágico/complicaciones , Sirtuina 1/metabolismoRESUMEN
Acute pulmonary embolism (APE) has a very high mortality rate, especially at cardiac arrest and even after the return of spontaneous circulation (ROSC). This study investigated the protective effect of the angiotensin-converting enzyme (ACE) inhibitor captopril on postresuscitation hemodynamics, in a porcine model of cardiac arrest established by APE. Twenty-nine Beijing Landrace pigs were infused with an autologous thrombus leading to cardiac arrest and subjected to standard cardiopulmonary resuscitation and thrombolysis. Ten resuscitated pigs were randomly and equally apportioned to receive either captopril (22.22 mg/kg) infusion or the same volume saline, 30 min after ROSC. Hemodynamic changes and ACE-Ang II-angiotensin II type 1 receptor (AT1R) and ACE2/Ang-(1-7)/Mas receptor axis levels were determined. APE was associated with a decline in mean arterial pressure and a dramatic increase in pulmonary artery pressure and mean right ventricular pressure. After ROSC, captopril infusion was associated with significantly lower mean right ventricular pressure and systemic and pulmonary vascular resistance, faster heart rate, and higher Ang-(1-7) levels, ACE2/ACE, and Ang-(1-7)/Ang II, compared with the saline infusion. The ACE2/Ang-(1-7)/Mas pathway correlated negatively with external vascular lung water and pulmonary vascular permeability and positively with the right cardiac index. In conclusion, in a pig model of APE leading to cardiac arrest, captopril infusion was associated with less mean right ventricular pressure overload after resuscitation, compared with saline infusion. The reduction in systemic and pulmonary vascular resistance associated with captopril may be by inhibiting the ACE-Ang II-AT1R axis and activating the ACE2/Ang-(1-7)/Mas axis.
Asunto(s)
Angiotensina I/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Captopril/farmacología , Reanimación Cardiopulmonar , Paro Cardíaco/terapia , Hemodinámica/efectos de los fármacos , Fragmentos de Péptidos/metabolismo , Peptidil-Dipeptidasa A/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Embolia Pulmonar/terapia , Receptores Acoplados a Proteínas G/metabolismo , Enzima Convertidora de Angiotensina 2 , Animales , Presión Arterial/efectos de los fármacos , Biomarcadores/sangre , Permeabilidad Capilar/efectos de los fármacos , Modelos Animales de Enfermedad , Activación Enzimática , Femenino , Paro Cardíaco/sangre , Paro Cardíaco/enzimología , Paro Cardíaco/fisiopatología , Masculino , Proto-Oncogenes Mas , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/fisiopatología , Edema Pulmonar/enzimología , Edema Pulmonar/fisiopatología , Edema Pulmonar/prevención & control , Embolia Pulmonar/sangre , Embolia Pulmonar/enzimología , Embolia Pulmonar/fisiopatología , Sistema Renina-Angiotensina/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Sus scrofa , Terapia Trombolítica , Factores de Tiempo , Resistencia Vascular/efectos de los fármacos , Función Ventricular Derecha/efectos de los fármacos , Presión Ventricular/efectos de los fármacosRESUMEN
The apoptosis of alveolar epithelial cells is important in seawater aspirationinduced acute lung injury (ALI). The present study aimed to investigate whether epigallocatechin-3-gallate (EGCG) is able to suppress apoptosis in alveolar epithelial cells in seawater aspirationinduced ALI in vivo and in vitro, and the possible mechanisms underlying it. The results indicated that seawater aspirationinduced ALI in rats is accompanied by increased apoptosis in lung tissue cells and the expression of apoptosisassociated proteins, caspase3 and p21. EGCG pretreatment significantly ameliorated seawater aspirationinduced ALI. Furthermore, EGCG decreased seawater aspirationinduced apoptosis and the expression of caspase3 and p21 in lung tissue cells. Seawaterchallenged A549 cells experienced increased apoptosis and elevated levels of phosphorylatedsignal transducer and activator of transcription 1 (PSTAT1). EGCG pretreatment of the cells resulted in significantly decreased seawaterinduced apoptosis and lower levels of STAT1 and PSTAT1 in A549 cells. This suggests that EGCG suppresses alveolar epithelial cell apoptosis in seawater aspirationinduced ALI via inhibiting the STAT1-caspase-3/p21 associated pathway.
Asunto(s)
Lesión Pulmonar Aguda/patología , Células Epiteliales Alveolares/patología , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Catequina/análogos & derivados , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Aspiración Respiratoria/patología , Factor de Transcripción STAT1/metabolismo , Lesión Pulmonar Aguda/complicaciones , Lesión Pulmonar Aguda/enzimología , Células Epiteliales Alveolares/efectos de los fármacos , Células Epiteliales Alveolares/metabolismo , Animales , Catequina/farmacología , Línea Celular Tumoral , Humanos , Pulmón/efectos de los fármacos , Pulmón/patología , Masculino , Fosforilación/efectos de los fármacos , Edema Pulmonar/complicaciones , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Ratas Sprague-Dawley , Aspiración Respiratoria/enzimología , Agua de Mar , Transducción de Señal/efectos de los fármacosRESUMEN
The lung and kidney are two organs that are easily affected by hemorrhagic shock (HS). We investigated roles of biliary tract external drainage (BTED) in inflammation and edema of the lung and kidney in HS and its relationship with the heme oxygenase-1 (HO-1) pathway. Rat models of HS were induced by drawing blood from the femoral artery until a mean arterial pressure (MAP) of 40 ± 5 mmHg was achieved. A MAP of 40 ± 5 mmHg was maintained for 60 min. Thirty-six Sprague-Dawley rats were randomized to the following groups: sham group; HS group; HS + zinc protoporphyrin IX (ZnPP), a specific HO-1 inhibitor, group; HS + BTED group; HS + BTED + ZnPP group; and HS + BTED + bile infusion (BI) group. HO-1 levels, aquaporin-1 levels, and ratios of dry/wet in the lung and kidney increased markedly after BTED, but tumor necrosis factor-α and myeloperoxidase levels in the lung and kidney decreased significantly after BTED under HS conditions. Under the condition that HO-1 was inhibited by ZnPP, all these effects induced by BTED disappeared in the lung and kidney. These results demonstrated that inflammation and edema of the lung and kidney of HS rats are alleviated by BTED via the HO-1 pathway.
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Procedimientos Quirúrgicos del Sistema Biliar/métodos , Drenaje/métodos , Hemo Oxigenasa (Desciclizante)/metabolismo , Riñón/efectos de los fármacos , Pulmón/efectos de los fármacos , Nefritis/prevención & control , Neumonía/prevención & control , Edema Pulmonar/prevención & control , Choque Hemorrágico/terapia , Animales , Acuaporina 1/genética , Acuaporina 1/metabolismo , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacología , Hemo Oxigenasa (Desciclizante)/antagonistas & inhibidores , Riñón/enzimología , Riñón/patología , Pulmón/enzimología , Pulmón/patología , Masculino , Nefritis/enzimología , Nefritis/genética , Nefritis/patología , Peroxidasa/metabolismo , Neumonía/enzimología , Neumonía/genética , Neumonía/patología , Protoporfirinas/farmacología , Edema Pulmonar/enzimología , Edema Pulmonar/genética , Edema Pulmonar/patología , Ratas Sprague-Dawley , Choque Hemorrágico/enzimología , Choque Hemorrágico/genética , Choque Hemorrágico/patología , Transducción de Señal , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia ArribaRESUMEN
Dexmedetomidine (Dex) is widely used for sedation in intensive care units and can be used as an adjunct to anesthetics. Previous studies have demonstrated that Dex has anti-inflammatory property. In this study, we aim to explore the potential therapeutic effects and mechanisms of Dex on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. To induce ALI, mice were intraperitoneally injected with LPS, while Dex was treated 1 h before LPS injection. The inflammation of lung tissues was evaluated by HE stain, and bronchoalveolar lavage fluid (BALF) was obtained after 6 h to measure protein concentrations. We also used an enzyme-linked immunosorbent assay to detect the secretion levels of proinflammatory cytokines in the serum. Western blotting method was adopted to observe changes in mitogen-activated protein kinases and downstream nuclear transcription factors. The results showed that pretreatment with Dex considerably reduced neutrophil infiltration and pulmonary edema, and significantly reduced protein concentrations in the BALF, as well as suppressed LPS-induced elevation of proinflammatory cytokines (TNF-α and IL-1ß) in the serum. In addition, we observed that the molecular mechanism of Dex-mediated anti-inflammation is associated with decreasing phosphorylation of MKK4, MMK3/6, ERK1/2, p38MAPK, and JNK, and diminishing activation of Elk-1, c-Jun, and ATF-2. Dex could attenuate ALI induced by LPS in mice, and this effect may be mediated through the inhibition of MAPK pathway.
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Lesión Pulmonar Aguda/prevención & control , Antiinflamatorios/farmacología , Dexmedetomidina/farmacología , Lipopolisacáridos , Pulmón/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/enzimología , Lesión Pulmonar Aguda/genética , Lesión Pulmonar Aguda/patología , Animales , Líquido del Lavado Bronquioalveolar/química , Citocinas/metabolismo , Citoprotección , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Activación Enzimática , Mediadores de Inflamación/metabolismo , Pulmón/enzimología , Pulmón/patología , Masculino , Ratones , Infiltración Neutrófila/efectos de los fármacos , Fosforilación , Edema Pulmonar/inducido químicamente , Edema Pulmonar/enzimología , Edema Pulmonar/prevención & control , Factores de Tiempo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética/efectos de los fármacosRESUMEN
Anthrax is associated with severe vascular leak, which is caused by the bacterial lethal toxin (LeTx). Pleural effusions and pulmonary edema that occur in anthrax are believed to reflect endothelial injury caused by the anthrax toxin. Since vascular leak can also be observed consistently in rats injected intravenously with LeTx, the latter might present a simple physiologically relevant animal model of acute lung injury (ALI). Such a model could be utilized in evaluating and developing better treatment for ALI or acute respiratory distress syndrome (ARDS), as other available rodent models do not consistently produce the endothelial permeability that is a major component of ARDS. The biological activity of LeTx resides in the lethal factor metalloprotease that specifically degrades MAP kinase kinases (MKKs). Recently, we showed that LeTx inactivation of p38 MAP kinase signaling via degradation of MKK3 in pulmonary vascular endothelial cells can be linked to compromise of the endothelial permeability barrier. LeTx effects were linked specifically to blocking activation of p38 substrate and MAP kinase-activated protein kinase 2 (MAPKAPK2 or MK2) and phosphorylation of the latter's substrate, heat shock protein 27 (HSP27). We have now designed a peptide that directly and specifically activates MK2, causing HSP27 phosphorylation in cells and in vivo. The MK2-activating peptide (MK2-AP) also blocks the effects of LeTx on endothelial barriers in cultured cells and reduces LeTx-induced pulmonary vascular leak in rats. Hence, MK2-AP has the therapeutic potential to counteract anthrax or pulmonary edema and vascular leak due to other causes.
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Lesión Pulmonar Aguda/prevención & control , Antígenos Bacterianos , Toxinas Bacterianas , Células Endoteliales/efectos de los fármacos , Activadores de Enzimas/farmacología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Pulmón/efectos de los fármacos , Péptidos/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Edema Pulmonar/prevención & control , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/enzimología , Animales , Permeabilidad Capilar/efectos de los fármacos , Células Cultivadas , Citoprotección , Modelos Animales de Enfermedad , Células Endoteliales/enzimología , Activación Enzimática , Proteínas de Choque Térmico HSP27/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Pulmón/irrigación sanguínea , Pulmón/enzimología , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Edema Pulmonar/inducido químicamente , Edema Pulmonar/enzimología , Interferencia de ARN , Ratas , Ratas Endogámicas F344 , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , TransfecciónRESUMEN
BACKGROUND: Mortality from severe acute respiratory distress syndrome exceeds 40% and there is no available pharmacologic treatment. Mechanical ventilation contributes to lung dysfunction and mortality by causing ventilator-induced lung injury. We explored the utility of simvastatin in a mouse model of severe ventilator-induced lung injury. METHODS: Male C57BL6 mice (n = 7/group) were pretreated with simvastatin or saline and received protective (8 mL/kg) or injurious (25 mL/kg) ventilation for four hours. Three doses of simvastatin (20 mg/kg) or saline were injected intraperitoneally on days -2, -1 and 0 of the experiment. Lung mechanics, (respiratory system elastance, tissue damping and airway resistance), were evaluated by forced oscillation technique, while respiratory system compliance was measured with quasi-static pressure-volume curves. A pathologist blinded to treatment allocation scored hematoxylin-eosin-stained lung sections for the presence of lung injury. Pulmonary endothelial dysfunction was ascertained by bronchoalveolar lavage protein content and lung tissue expression of endothelial junctional protein Vascular Endothelial cadherin by immunoblotting. To assess the inflammatory response in the lung, we determined bronchoalveolar lavage fluid total cell content and neutrophil fraction by microscopy and staining in addition to Matrix-Metalloprotease-9 by ELISA. For the systemic response, we obtained plasma levels of Tumor Necrosis Factor-α, Interleukin-6 and Matrix-Metalloprotease-9 by ELISA. Statistical hypothesis testing was undertaken using one-way analysis of variance and Tukey's post hoc tests. RESULTS: Ventilation with high tidal volume (HVt) resulted in significantly increased lung elastance by 3-fold and decreased lung compliance by 45% compared to low tidal volume (LVt) but simvastatin abrogated lung mechanical alterations of HVt. Histologic lung injury score increased four-fold by HVt but not in simvastatin-pretreated mice. Lavage pleocytosis and neutrophilia were induced by HVt but were significantly attenuated by simvastatin. Microvascular protein permeability increase 20-fold by injurious ventilation but only 4-fold with simvastatin. There was a 3-fold increase in plasma Tumor Necrosis Factor-α, a 7-fold increase in plasma Interleukin-6 and a 20-fold increase in lavage fluid Matrix-Metalloprotease-9 by HVt but simvastatin reduced these levels to control. Lung tissue vascular endothelial cadherin expression was significantly reduced by injurious ventilation but remained preserved by simvastatin. CONCLUSION: High-dose simvastatin prevents experimental hyperinflation lung injury by angioprotective and anti-inflammatory effects.
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Antiinflamatorios/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Pulmón/efectos de los fármacos , Simvastatina/farmacología , Lesión Pulmonar Inducida por Ventilación Mecánica/prevención & control , Resistencia de las Vías Respiratorias/efectos de los fármacos , Animales , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Permeabilidad Capilar/efectos de los fármacos , Modelos Animales de Enfermedad , Elasticidad , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Mediadores de Inflamación/sangre , Pulmón/enzimología , Pulmón/patología , Pulmón/fisiopatología , Rendimiento Pulmonar/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Neumonía/enzimología , Neumonía/patología , Neumonía/fisiopatología , Neumonía/prevención & control , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Edema Pulmonar/fisiopatología , Edema Pulmonar/prevención & control , Factores de Tiempo , Lesión Pulmonar Inducida por Ventilación Mecánica/enzimología , Lesión Pulmonar Inducida por Ventilación Mecánica/patología , Lesión Pulmonar Inducida por Ventilación Mecánica/fisiopatologíaRESUMEN
OBJECTIVE: Lung ischemia-reperfusion (IR) injury during cardiopulmonary surgery is associated with postoperative morbidity and mortality, particularly in patients with pulmonary hypertension (PH). Using a rat model for monocrotaline-induced PH, we investigated the protective effect of rosuvastatin against IR injury in lungs affected by PH and attempted to elucidate its mechanism of action. METHODS: Male Sprague-Dawley monocrotaline-treated rats were divided into 4 groups (n = 8-9): sham, control + IR, statin + IR, and statin + mevalonolactone + IR. Lung ischemia was induced by left pulmonary artery occlusion (1 hour), followed by reperfusion (4 hours). Rosuvastatin (2 mg/kg) was injected 18 hours before reperfusion and mevalonolactone (1 mg/kg) was injected immediately before reperfusion. The arterial oxygen tension/inspired oxygen fraction ratio was used as a measure of lung oxygenation. Left lung tissue was analyzed for the wet-to-dry lung weight ratio and protein expression of endothelial nitric oxide synthase (eNOS) and phospho-eNOS. Macrophage recruitment was assessed by CD68 immunostaining. RESULTS: Our results showed that rosuvastatin decreased IR lung injury (control + IR vs statin + IR) in terms of the arterial oxygen tension/inspired oxygen fraction ratio (272 ± 43 vs 442 ± 13), wet-to-dry ratio (5.7 ± 0.7 vs 4.8 ± 0.6), and macrophage infiltration (8.0 ± 0.6/field vs 4.0 ± 0.5/field) (P < .05 for all). eNOS and phospho-eNOS were downregulated by IR, which was blocked by rosuvastatin. Effects of rosuvastatin were blunted by mevalonolactone. CONCLUSIONS: Single-dose rosuvastatin decreased IR injury in lungs affected by PH via 2 anti-inflammatory mechanisms: preserving eNOS function and inhibiting macrophage infiltration.
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Antiinflamatorios/farmacología , Endotelio Vascular/efectos de los fármacos , Fluorobencenos/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Hipertensión Pulmonar/tratamiento farmacológico , Lesión Pulmonar/prevención & control , Pulmón/efectos de los fármacos , Macrófagos/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Pirimidinas/farmacología , Daño por Reperfusión/prevención & control , Sulfonamidas/farmacología , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Modelos Animales de Enfermedad , Endotelio Vascular/enzimología , Endotelio Vascular/inmunología , Endotelio Vascular/fisiopatología , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/enzimología , Hipertensión Pulmonar/inmunología , Hipertensión Pulmonar/fisiopatología , Pulmón/irrigación sanguínea , Pulmón/enzimología , Pulmón/inmunología , Pulmón/fisiopatología , Lesión Pulmonar/enzimología , Lesión Pulmonar/inmunología , Lesión Pulmonar/fisiopatología , Macrófagos/enzimología , Macrófagos/inmunología , Masculino , Ácido Mevalónico/análogos & derivados , Ácido Mevalónico/farmacología , Monocrotalina , Oxígeno/sangre , Fosforilación , Edema Pulmonar/enzimología , Edema Pulmonar/inmunología , Edema Pulmonar/prevención & control , Ratas Sprague-Dawley , Daño por Reperfusión/enzimología , Daño por Reperfusión/inmunología , Daño por Reperfusión/patología , Rosuvastatina Cálcica , Regulación hacia ArribaRESUMEN
BACKGROUND: Ventilator-induced lung injury (VILI) is characterized by increased alveolar permeability, pulmonary edema. The tyrosine kinase, c-Src, is involved in VILI but its role has not been fully elucidated. This study examined the relationship between c-Src activation and occludin levels in VILI both in vitro and in vivo. METHODS: For the in vivo study, Wistar rats were randomly divided into five groups: control (group C); normal tidal volume (group M); normal tidal volume + c-Src inhibitor (PP2) (group M + P); high tidal volume (group H); and high tidal volume + c-Src inhibitor (PP2) (group H + P). Rats in all groups but group C underwent mechanical ventilation for 4 h. For the in vitro study, MLE-12 cells pretreated with PP2 and siRNA underwent cyclic stretching at 8% or 20% for 0, 1, 2 and 4 h. The expressions of occludin, c-Src, and p-c-Src were analyzed by western blotting, hematoxylin and eosin (HE) staining, and immunofluorescence. RESULTS: For the in vivo study, rats in group H showed decreased occludin expression and activated c-Src compared with group C. HE staining and lung injury score showed more severe lung injury and alveolar edema in group H compared with group M and group C. Group H + P had less pulmonary edema induced by the high tidal volume ventilation. For the in vitro study, occludin expression decreased and c-Src activation increased as indicated by the phosphorylation of c-Src over time. Consistently, PP2 could restore occludin levels. CONCLUSIONS: Mechanical ventilation can activate c-Src by phosphorylation and increase the degradation of occludin. c-Src inhibitor can ameliorate barrier function and lung injury by up-regulating occludin.
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Pulmón/enzimología , Ocludina/metabolismo , Lesión Pulmonar Inducida por Ventilación Mecánica/enzimología , Familia-src Quinasas/metabolismo , Animales , Proteína Tirosina Quinasa CSK , Línea Celular , Modelos Animales de Enfermedad , Activación Enzimática , Pulmón/efectos de los fármacos , Pulmón/fisiopatología , Mecanotransducción Celular , Ratones , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Proteolisis , Edema Pulmonar/enzimología , Interferencia de ARN , Ratas Wistar , Factores de Tiempo , Transfección , Lesión Pulmonar Inducida por Ventilación Mecánica/fisiopatología , Familia-src Quinasas/antagonistas & inhibidores , Familia-src Quinasas/genéticaRESUMEN
Although AMP-activated protein kinase (AMPK) is involved in regulating carbohydrate and lipid metabolism, activated AMPK also plays an anti-inflammatory role in many cell populations. However, despite the ability of AMPK activation to diminish the severity of inflammatory responses, previous studies have found that AMPK activity is diminished in LPS-treated neutrophils and also in lungs of mice with LPS-induced acute lung injury (ALI). Since GSK3ß participates in regulating AMPK activity, we examined potential roles for GSK3ß in modulating LPS-induced activation of neutrophils and macrophages and in influencing severity of ALI. We found that GSK3ß-dependent phosphorylation of T479-AMPK was associated with pT172 dephosphorylation and inactivation of AMPK following TLR4 engagement. GSK3ß inhibitors BIO (6-bromoindirubin-3'-oxime), SB216763, or siRNA knockdown of GSK3ß, but not the PI3K/AKT inhibitor LY294002, prevented Thr172-AMPK dephosphorylation. Exposure to LPS resulted in rapid binding between IKKß and AMPKα, and phosphorylation of S485-AMPK by IKKß. These results suggest that IKKß-dependent phosphorylation of S485-AMPK was an essential step in subsequent phosphorylation and inactivation AMPK by GSK3ß. Inhibition of GSK3ß activity delayed IκBα degradation and diminished expression of the proinflammatory TNF-α in LPS-stimulated neutrophils and macrophages. In vivo, inhibition of GSK3ß decreased the severity of LPS-induced lung injury as assessed by development of pulmonary edema, production of TNF-α and MIP-2, and release of the alarmins HMGB1 and histone 3 in the lungs. These results show that inhibition of AMPK by GSK3ß plays an important contributory role in enhancing LPS-induced inflammatory responses, including worsening the severity of ALI.
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Proteínas Quinasas Activadas por AMP/metabolismo , Lesión Pulmonar Aguda/enzimología , Glucógeno Sintasa Quinasa 3/metabolismo , Activación de Macrófagos , Macrófagos/enzimología , Activación Neutrófila , Neutrófilos/enzimología , Proteínas Quinasas Activadas por AMP/antagonistas & inhibidores , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/patología , Animales , Línea Celular , Quimiocina CXCL2/metabolismo , Cromonas/farmacología , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3 beta , Proteína HMGB1/metabolismo , Quinasa I-kappa B/metabolismo , Indoles/farmacología , Lipopolisacáridos/toxicidad , Macrófagos/patología , Maleimidas/farmacología , Ratones , Morfolinas/farmacología , Neutrófilos/patología , Fosforilación/efectos de los fármacos , Edema Pulmonar/inducido químicamente , Edema Pulmonar/enzimología , Edema Pulmonar/patología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Inflammation is a key process in various diseases, characterized by leukocyte recruitment to the inflammatory site. This study investigates the role of a disintegrin and a metalloproteinase (ADAM) 10 and ADAM17 for leukocyte migration in vitro and in a murine model of acute pulmonary inflammation. Inhibition experiments or RNA knockdown indicated that monocytic THP-1 cells and primary human neutrophils require ADAM10 but not ADAM17 for efficient chemokine-induced cell migration. Signaling and adhesion events that are linked to cell migration such as p38 and ρ GTPase-family activation, F-actin polymerization, adhesion to fibronectin, and up-regulation of α5 integrin were also dependent on ADAM10 but not ADAM17. This was confirmed with leukocytes isolated from mice lacking either ADAM10 or ADAM17 in all hematopoietic cells (vav 1 guanine nucleotide exchange factor [Vav]-Adam10(-/-) or Vav-Adam17(-/-) mice). In lipopolysaccharide-induced acute pulmonary inflammation, alveolar recruitment of neutrophils and monocytes was transiently increased in Vav-Adam17(-/-) but steadily reduced in Vav-Adam10(-/-) mice. This deficit in alveolar leukocyte recruitment was also observed in LysM-Adam10(-/-) mice lacking ADAM10 in myeloid cells and correlated with protection against edema formation. Thus, with regard to leukocyte migration, leukocyte-expressed ADAM10 but not ADAM17 displays proinflammatory activities and may therefore serve as a target to limit inflammatory cell recruitment.
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Proteínas ADAM/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Movimiento Celular , Proteínas de la Membrana/metabolismo , Infiltración Neutrófila , Neutrófilos/enzimología , Neumonía/enzimología , Alveolos Pulmonares/enzimología , Edema Pulmonar/enzimología , Proteínas ADAM/genética , Proteína ADAM10 , Proteína ADAM17 , Enfermedad Aguda , Secretasas de la Proteína Precursora del Amiloide/genética , Animales , Línea Celular Tumoral , Células HEK293 , Humanos , Inflamación/inducido químicamente , Inflamación/enzimología , Inflamación/genética , Inflamación/patología , Lipopolisacáridos/toxicidad , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Neutrófilos/patología , Neumonía/inducido químicamente , Neumonía/genética , Neumonía/patología , Alveolos Pulmonares/patología , Edema Pulmonar/inducido químicamente , Edema Pulmonar/genética , Edema Pulmonar/patologíaRESUMEN
There is a large body of evidence that nitric oxide (NO) formation is implicated in mediating silica-induced pulmonary fibrosis. As a reactive free radical, NO may not only contribute to lung parenchymal tissue injury but also has the ability to combine with superoxide and form a highly reactive toxic species peroxynitrite that can induce extensive cellular toxicity in the lung tissues. This study aimed to explore the effect of agmatine, a known NO synthase inhibitor, on silica-induced pulmonary fibrosis in rats. Male Sprague Dawley rats were treated with agmatine for 60 days following a single intranasal instillation of silica suspension (50 mg in 0.1 ml saline/rat). The results revealed that agmatine attenuated silica-induced lung inflammation as it decreased the lung wet/dry weight ratio, protein concentration, and the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid. Agmatine showed antifibrotic activity as it decreased total hydroxyproline content of the lung and reduced silica-mediated lung inflammation and fibrosis in lung histopathological specimen. In addition, agmatine significantly increased superoxide dismutase (p < 0.001) and reduced glutathione (p < 0.05) activities with significant decrease in the lung malondialdehyde (p < 0.001) content as compared to the silica group. Agmatine also reduced silica-induced overproduction of pulmonary nitrite/nitrate as well as tumor necrosis factor α. Collectively, these results demonstrate the protective effects of agmatine against the silica-induced lung fibrosis that may be attributed to its ability to counteract the NO production, lipid peroxidation, and regulate cytokine effects.