RESUMEN
No disponible
Asunto(s)
Humanos , Respiración Artificial/métodos , Anestesia General/métodos , Trastornos Respiratorios/prevención & control , Lesión Pulmonar/etiología , Complicaciones Posoperatorias/prevención & control , Factores de Riesgo , Lesión Pulmonar/fisiopatología , Manejo de la Vía Aérea/efectos adversosRESUMEN
Understanding connectivity patterns has implications for evolutionary and ecological processes, as well as for proper conservation strategies. This study examined population genetic structure and migration patterns of the coral Mussismilia hispida, one of the main reef builders in the Southwestern Atlantic Ocean. For this, 15 sites were sampled along its entire distributional range employing 10 microsatellite loci. M. hispida was divided into five genetically differentiated populations by Structure analysis. Population structure and migration estimates are consistent with present-day oceanographic current patterns, zones of upwelling and historical sea-level changes. The Central Region and Oceanic Islands populations had the highest genetic diversity, were possibly the main sources of migrants for other populations and presented mutual migrant exchange. This mutual exchange and the high diversity of Oceanic Islands, a peripherical population, is highly interesting and unexpected, but can be explained if these sites acted as refugia in past low sea-level stance. This is the first connectivity study in the region using hyper-variable markers and a fine sampling scale along 3,500 km. These results enlighten the population dynamics of an important reef building species and shows how oceanographic processes may act as barriers to dispersal for marine species, providing valuable information for management strategies.
Asunto(s)
Antozoos/genética , Animales , Océano Atlántico , Arrecifes de Coral , Flujo Génico , Variación Genética , Genética de Población , Genotipo , Repeticiones de Microsatélite , Oceanografía , Dinámica Poblacional , Análisis de Componente Principal , Análisis de Secuencia de ADN/métodosAsunto(s)
Complicaciones Posoperatorias/prevención & control , Trastornos Respiratorios/prevención & control , Respiración Artificial/métodos , Adulto , Anciano , Periodo de Recuperación de la Anestesia , Anestesia General , Medicina Basada en la Evidencia , Femenino , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Alveolos Pulmonares/fisiopatología , Trastornos Respiratorios/etiología , Trastornos Respiratorios/fisiopatología , Respiración Artificial/efectos adversos , Medición de RiesgoRESUMEN
Interleukin-8 (IL-8) is released in response to inflammatory stimuli, such as bacterial products. Either porins or lipopolysaccharide (LPS) stimulated THP-1 cells to release IL-8 after 24 h. We have previously reported that stimulation of monocytic cells with Salmonella enterica serovar Typhimurium porins led to the activation of mitogen-activated protein kinase cascades and of protein tyrosine kinases (PTKs). In this report, we demonstrate, using two potent and selective inhibitors of MEK activation by Raf-1 (PD-098059) and p38 (SB-203580), that both ERK1/2 and p38 pathways play a key role in the production of IL-8 by porins and LPS. Porin-stimulated expression of activating protein 1 (AP-1) and correlated IL-8 release is also inhibited by PD-098059 or SB-203580 indicating that the Raf-1/MEK1-MEK2/MAPK cascade is required for their activation. Also PTKs modulate the pathway that control IL-8 gene expression, in fact its expression is abolished by tyrphostin. By using N-acetyl-leucinyl-leucinyl-norleucinal-H (ALLN) an inhibitor of nuclear factor-kappaB (NF-kappaB) activity, we also observed IL-8 release modulation. Our results elucidate some of the molecular mechanisms by which AP-1 and NF-kappaB regulate IL-8 release and open new strategies for the design of specific molecules that will modulate IL-8 effects in various infectious diseases.
Asunto(s)
Interleucina-8/biosíntesis , Sistema de Señalización de MAP Quinasas , FN-kappa B/metabolismo , Porinas/farmacología , Salmonella typhimurium/fisiología , Factor de Transcripción AP-1/metabolismo , Línea Celular , Flavonoides/farmacología , Humanos , Imidazoles/farmacología , Interleucina-8/genética , Lipopolisacáridos/farmacología , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Unión Proteica/efectos de los fármacos , Piridinas/farmacología , Salmonella typhimurium/química , Transducción de Señal , Factor de Transcripción AP-1/genética , Tirfostinos/farmacología , Regulación hacia Arriba/genéticaRESUMEN
OBJECTIVES: In the present study a monocytic cell line, U937, was used to investigate the possible involvement of protein tyrosine kinases (NT-PTKs), protein kinase A (PKA) and protein kinase C (PKC) in cell signaling pathways following Salmonella enterica serovar Typhimurium porin stimulation. METHODS: Different concentrations of porins and lipopolysaccharide (LPS) were analysed to evaluate changes in PTK activity by a non radioactive tyrosine kinase assay and in PKA and PKC phosphorylation by Western blotting analysis. The inhibitors of PTK, PKA and PKC activation used, were: 3,4-dihydroxybenzylidene-malononitrile (tyrphostin 23), inhibitor of epidermal growth factor (EGF) receptor tyrosine kinase activity; dihychloride (H-89), a selective inhibitor of PKA which is useful to discriminate between the effects of PKC and PKA; diacylglycerol kinase inhibitor II (R59949), which is useful for elucidating roles of PKC; calphostin C, a specific inhibitor of PKC. RESULTS: Porins of the outer membrane of the ST were isolated to be used as a stimulus in the performed experiments. Following porin treatment, a dose-dependent increase in PTK, PKA and PKC activation was observed. U937 monocytes pretreated with inhibitors induced an evident decrease in PTK activity and PKA and PKC phosphorylation pattern in porin stimulated monocytes. CONCLUSIONS: Our data support the important role played by NT-PTK, PKA and PKC in transducing the activating signal in macrophages stimulated with porins through the activation of the mitogen-activated protein kinase (MAPK) pathway that participate in the regulation of gene expression.
Asunto(s)
Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Monocitos/enzimología , Porinas/farmacología , Proteína Quinasa C/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Salmonella typhimurium/metabolismo , Sulfonamidas , Western Blotting , Proteínas Quinasas Dependientes de AMP Cíclico/antagonistas & inhibidores , Electroforesis en Gel de Poliacrilamida , Ensayo de Cambio de Movilidad Electroforética , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Humanos , Isoquinolinas/farmacología , L-Lactato Deshidrogenasa/metabolismo , Lipopolisacáridos/farmacología , Monocitos/microbiología , Naftalenos/farmacología , Piperidinas/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Quinazolinas/farmacología , Quinazolinonas , Salmonella typhimurium/química , Transducción de Señal/fisiología , Tirfostinos/farmacología , Células U937RESUMEN
The effect of porins purified from Salmonella typhimurium, Pasteurella haemolytica and Haemophilus influenzae on induction of tyrosine phosphorylation in THP-1 cells and C3H/HeJ macrophage was investigated. Incubation of porins at concentration of 1.0-5.0 microg ml(-1) with either THP-1 or macrophage from C3H/HeJ mice resulted in tyrosine phosphorylation of specific host cell proteins. After porin stimulation a pattern of tyrosine phosphorylated proteins appeared in the soluble cytoplasmic fraction, in the membrane fraction and in the insoluble protein fraction. The observed effects were dependent on the porin concentrations; they reached a maximal expression at 3 min and declined at 60 min. Porin and lipopolysaccharide treatments induce a similar phosphorylation pattern in all of the three cellular fractions studied. A difference can be observed in the cytoplasmic fraction bands of 50-60 kDa, which are more evident after treatment with lipopolysaccharide, and in the insoluble fraction band of 80 kDa and the cytoplasmic fraction band of 250 kDa, which are more evident after treatment with porins. The events of tyrosine protein phosphorylation were present in macrophage from lipopolysaccaride-hyporesponsive C3H/HeJ mice stimulated with porins, while they were markedly reduced when the cells were stimulated with lipopolysaccharide. Staurosporine, genistein and cytochalasin D induced in the three cellular fractions a different inhibition pattern of tyrosine protein phosphorylation in porin stimulated cells. Porins extracted from the three bacterial species investigated behave in a similar way as stimuli more or less potent; Hib porin seems to be the most powerful stimulator and, moreover, it specifically induces phosphorylation of a 55 kDa band.
Asunto(s)
Haemophilus influenzae , Macrófagos Peritoneales/efectos de los fármacos , Mannheimia haemolytica , Fosfoproteínas/metabolismo , Fosfotirosina/metabolismo , Porinas/farmacología , Salmonella typhimurium , Animales , Western Blotting , Línea Celular , Femenino , Humanos , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Macrófagos Peritoneales/microbiología , Ratones , Ratones Endogámicos C3H , Peso Molecular , Fosfoproteínas/química , Fosforilación/efectos de los fármacos , Porinas/aislamiento & purificaciónRESUMEN
We examined alpha1(I) collagen expression by using primary cultures of quail epiphyseal chondrocytes which exhibit high levels of synthesis of cartilage-specific collagens and do not undergo phenotypic modulation when replated onto collagens I and II or fibronectin. These cells also synthesize proalpha1(I) collagen chain, however, alpha1(I) mRNA fails to be detected by Northern blot and RNase protection analysis. Nuclear transcription rate with a 5-end specific probe is detected in suspension quail chondrocytes and RT-PCR analysis shows the presence of low levels of alpha1(I) mRNA in these cells. The lack of correspondence between procollagen mRNA levels and the rate of collagen synthesis is consistent with previous reports describing the regulation of this transcript in chondrocytes and in collagen I-producing cells.