Protease-activated receptor (Par)1 alters bioelectric properties of distal lung epithelia without compromising barrier function.

Proteinases contribute to the pathogenesis of various lung diseases, partly through activating cell surface receptors by limited proteolytic cleavage. The authors provide evidence that in primary cultures of distal lung epithelia, basolateral protease-activated receptor 1 activation rapidly reduces transepithelial resistance but does not alter paracellular permeability to small uncharged solutes. Changes in transepithelial resistance were partially blocked by ion transport inhibitors and were completely blocked by placing cells in low chloride buffer. In vivo studies did not reveal enhanced lung permeability in response to pulmonary or intravenous administration of protease-activated receptor 1 activators. This information is relevant as strategies to inhibit protease-activated receptor 1 signaling are considered in order to preserve lung epithelial barrier function.

Incidencia de algunos factores sociales en el incremento del cáncer de mama / Incidence of some social factors in breast cancer increase

Se realizó un estudio observacional, descriptivo y longitudinal de 95 pacientes (90 mujeres y 5 hombres), atendidos en la consulta de Mastología del Hospital Oncológico Provincial Docente Conrado Benítez de Santiago de Cuba, desde enero de 2014 hasta febrero de 2015, con vistas a determinar los factores sociales que inciden en el incremento del cáncer de mama y, a partir de entonces, elaborar una propuesta de acciones que permitan potenciar la promoción y educación para la salud. Fueron aplicados técnicas cualitativas que permitieron conocer las experiencias, las actitudes, los pensamientos y las reflexiones de los participantes expertos. Se observó que la mayoría de los pacientes (67,4 por ciento) desconocían lo relacionado con las actividades de promoción de salud desarrolladas por las organizaciones de masas, así como el pobre desempeño de los médicos de familia en este sentido(AU)

An observational, descriptive and longitudinal study of 95 patients (90 women and 5 men), assisted in the Breast Service of Conrado Benítez Teaching Provincial Cancer Hospital in Santiago de Cuba, was carried out from January, 2014 to February, 2015, aimed at determining the social factors that impact in the increase of breast cancer and, from that time on, elaborate a proposal of actions that allow the promotion and education for health. Some qualitative techniques were implemented that allowed to know the experiences, attitudes, thoughts and reflections of the expert participants. It was observed that most of the patients (67.4 percent) ignored everything related to the activities of health promotion developed by the masses organizations, as well as the poor performance of the family doctors in this sense(AU)

Incidencia de algunos factores sociales en el incremento del cáncer de mama / Incidence of some social factors in breast cancer increase

Se realizó un estudio observacional, descriptivo y longitudinal de 95 pacientes (90 mujeres y 5 hombres), atendidos en la consulta de Mastología del Hospital Oncológico Provincial Docente Conrado Benítez de Santiago de Cuba, desde enero de 2014 hasta febrero de 2015, con vistas a determinar los factores sociales que inciden en el incremento del cáncer de mama y, a partir de entonces, elaborar una propuesta de acciones que permitan potenciar la promoción y educación para la salud. Fueron aplicados técnicas cualitativas que permitieron conocer las experiencias, las actitudes, los pensamientos y las reflexiones de los participantes expertos. Se observó que la mayoría de los pacientes (67,4 por ciento) desconocían lo relacionado con las actividades de promoción de salud desarrolladas por las organizaciones de masas, así como el pobre desempeño de los médicos de familia en este sentido

An observational, descriptive and longitudinal study of 95 patients (90 women and 5 men), assisted in the Breast Service of Conrado Benítez Teaching Provincial Cancer Hospital in Santiago de Cuba, was carried out from January, 2014 to February, 2015, aimed at determining the social factors that impact in the increase of breast cancer and, from that time on, elaborate a proposal of actions that allow the promotion and education for health. Some qualitative techniques were implemented that allowed to know the experiences, attitudes, thoughts and reflections of the expert participants. It was observed that most of the patients (67.4 percent) ignored everything related to the activities of health promotion developed by the masses organizations, as well as the poor performance of the family doctors in this sense

Role of PAR2 in murine pulmonary pseudomonal infection.

Proteinases can influence lung inflammation by various mechanisms, including via cleavage and activation of protease-activated receptors (PAR) such as PAR2. In addition, proteinases such as neutrophil and/or Pseudomonas-derived elastase can disarm PAR2 resulting in loss of PAR2 signaling. Currently, the role of PAR2 in host defense against bacterial infection is not known. Using a murine model of acute Pseudomonas aeruginosa pneumonia, we examined differences in the pulmonary inflammatory response between wild-type and PAR2(-/-) mice. Compared with wild-type mice, PAR2(-/-) mice displayed more severe lung inflammation and injury in response to P. aeruginosa infection as indicated by higher bronchoalveolar lavage fluid neutrophil numbers, protein concentration, and TNF-alpha levels. By contrast, IFN-gamma levels were markedly reduced in PAR2(-/-) compared with wild-type mice. Importantly, clearance of P. aeruginosa was diminished in PAR2(-/-) mice. In vitro testing revealed that PAR2(-/-) neutrophils killed significantly less bacteria than wild-type murine neutrophils. Further, both neutrophils and macrophages from PAR2(-/-) mice displayed significantly reduced phagocytic efficiency compared with wild-type phagocytes. Stimulation of PAR2 on macrophages using a PAR2-activating peptide resulted in enhanced phagocytosis directly implicating PAR2 signaling in the phagocytic process. We conclude that genetic deletion of PAR2 is associated with decreased clearance of P. aeruginosa. Our data suggest that a deficiency in IFN-gamma production and impaired bacterial phagocytosis are two potential mechanisms responsible for this defect.

CD44-mediated phagocytosis induces inside-out activation of complement receptor-3 in murine macrophages.

Diverse receptors, including Fcgamma receptors and beta(2) integrins (complement receptor-3 [CR3], CD11b/CD18), have been implicated in phagocytosis, but their distinct roles and interactions with other receptors in particle engulfment are not well defined. CD44, a transmembrane adhesion molecule involved in binding and metabolism of hyaluronan, may have additional functions in regulation of inflammation and phagocytosis. We have recently reported that CD44 is a fully competent phagocytic receptor that is able to trigger ingestion of large particles by macrophages. Here, we investigated the role of coreceptors and intracellular signaling pathways in modulation of CD44-mediated phagocytosis. Using biotinylated erythrocytes coated with specific antibodies (anti-CD44-coated erythrocytes [Ebabs]) as the phagocytic prey, we determined that CD44-mediated phagocytosis is reduced by 45% by a blocking CD11b antibody. Further, CD44-mediated phagocytosis was substantially (42%) reduced in CD18-null mice. Immunofluorescence microscopy revealed that CD11b is recruited to the phagocytic cup. The mechanism of integrin activation and mobilization involved activation of the GTPase Rap1. CD44-mediated phagocytosis was also sensitive to the extracellular concentration of the divalent cation Mg(2+) but not Ca(2+). In addition, buffering of intracellular Ca(2+) did not affect CD44-mediated phagocytosis. Taken together, these data suggest that CD44 stimulation induces inside-out activation of CR3 through the GTPase Rap1.

CD44 is a phagocytic receptor.

CD44, a transmembrane adhesion molecule involved in binding and metabolism of hyaluronan, has additional functions in inflammatory and immune responses, contributing to the ingestion and clearance of particles and apoptotic cells. Our goal was to determine the specific role of CD44 in phagocytosis and whether it functions as a primary or accessory phagocytic receptor. Using hyaluronan-coated beads and erythrocytes coated with antiCD44 antibodies as the phagocytic prey, we determined that CD44 mediates efficient phagocytosis in primary murine peritoneal macrophages and in the murine macrophage cell line RAW 264.7. In RAW cells, the phagocytic index for anti-CD44-coated erythrocytes was 25 +/- 3 (mean +/- SEM) compared with less than 1 for erythrocytes coated with isotype-matched control antibodies. Uptake of anti-CD44-coated erythrocytes was abrogated by pretreatment with a blocking antibody to CD44 and was absent in primary cultures of CD44-deficient murine macrophages. Down-regulation of Fc receptors by aggregated IgG-induced internalization, which blocks uptake of IgG-coated particles, had no effect on CD44-mediated particle engulfment. Using a combination of immunoprecipitation, pharmacologic inhibition, and genetic deletion, we determined that CD44-mediated phagocytosis involves Syk, Rac1, and phosphatidylinositol 3-kinase and induced activation of the phagocyte oxidase. We conclude that CD44 is a competent phagocytic receptor that efficiently mediates internalization of large particles.

Abnormalities in the pulmonary innate immune system in cystic fibrosis.

Pulmonary infection is the dominant clinical feature of cystic fibrosis (CF), but the basis for this susceptibility remains incompletely understood. One hypothesis is that CF airway surface liquid (ASL) is abnormal and interferes with neutrophil function. To study this possibility, we developed an in vitro system in which we collected ASL from primary cultures of normal and CF airway epithelial cells. Microbial killing was less efficient when bacteria were incubated with neutrophils in the presence of ASL from CF epithelia compared with normal ASL. Antimicrobial functions of human neutrophils were assessed in ASL from CF and normal epithelia using a combination of quantitative bacterial culture, flow cytometry, and microfluorescence imaging. The results of these assays of neutrophil function were indistinguishable in CF and normal ASL. In contrast, the direct bactericidal activity of ASL to Escherichia coli and to clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa was substantially less in CF than in normal ASL, even when highly diluted in media of identical ionic strength. Together, these observations indicate that the antimicrobial properties of ASL in CF are compromised in a manner independent of ionic strength of the ASL, and that this effect is not mediated through a direct effect of the ASL on phagocyte function.