Montelukast, Leukotriene Inhibitor, Reduces LPS-Induced Acute Lung Inflammation and Human Neutrophil Activation / El montelukast, un inhibidor de leucotrienos, reduce la inflamación pulmonar aguda inducida por LPS y la activación de neutrófilos humanos

Objectives: Some pro-inflammatory lipids derived from 1 lipooxygenase enzyme are potent neutrophil chemoattractant, a cell centrally involved in acute respiratory distress syndrome (ARDS); a syndrome lacking effective treatment. Considering the beneficial effects of the leukotriene receptor inhibitor, montelukast, on other lung diseases, whether montelukast attenuates inflammation in a mouse model of ARDS, and whether it reduces LPS stimulated activation of human neutrophils was investigated. Methods: Thirty-five C57Bl/6 mice were distributed into control (PBS) + 24h, LPS + 24h (10 μg/mouse), control + 48 h, LPS+48 h, and LPS 48 h+Montelukast (10 mg/kg). In addition, human neutrophils were incubated with LPS ( 1μg/mL) and treated with montelukast (10 μM). Results: Oral-tracheal administration of montelukast significantly attenuated total cells (P < .05), macrophages (P < .05), neutrophils (P < .01), lymphocytes (P < .001) and total protein levels in BAL (P < .05), as well as IL-6 (P < .05), CXCL1/KC (P < .05), IL-17 (P < .05) and TNF-alfa (P < .05). Furthermore, montelukast reduced neutrophils (P < .001), lymphocytes (P < .01) and macrophages (P < .01) in the lung parenchyma. In addition, montelukast restored BAL VEGF levels (P < .05). LTB4 receptor expression (P < .001) as well as NF-κB (P <. 001), a downstream target of LPS, were also reduced in lung parenchymal leukocytes. Furthermore, montelukast reduced IL-8 (P < .001) production by LPS-treated human neutrophils. Conclusion: In conclusion, montelukast efficiently attenuated both LPS-induced lung inflammation in a mouse model of ARDS and in LPS challenged human neutrophils

Objetivos: Algunos lípidos proinflamatorios derivados de la enzima lipooxigenasa 1 son potentes quimioatrayentes de neutrófilos, un tipo celular con una implicación principal en el síndrome de distrés respiratorio agudo (SDRA), para el que no hay tratamiento efectivo. Considerando los efectos beneficiosos del inhibidor de los receptores de leucotrienos montelukast en otras enfermedades pulmonares, se investigó si este fármaco era capaz de atenuar la inflamación en un modelo de ratón de SDRA y de reducir la activación de los neutrófilos humanos inducida por LPS. Métodos: Se utilizaron 35 ratones C57BL/6 distribuidos en los siguientes grupos: control (PBS) + 24 h, LPS+(24 h [10 μg/ratón]), control + 48 h y LPS 48 h + montelukast (10 mg/kg). Por otro lado, se incubaron neutrófilos humanos con LPS (1 μg/ml) y se trataron con montelukast (10 μM). Resultados: La administración orotraqueal de montelukast redujo el número total de células (p < 0,05), de macrófagos (p < 0,05), de neutrófilos (p < 0,01), de linfocitos (p < 0,001) y los niveles totales de proteína en el lavado broncoalveolar (p < 0,05), así como de IL-6 (p < 0,05), CXCL1/KC (p < 0,05), IL-17 (p < 0,05) y TNF-alfa (p < 0,05). Además, el montelukast redujo los neutrófilos (p < 0,001), los linfocitos (p < 0,01) y los macrófagos (p < 0,01) en el parénquima pulmonar. Asimismo, restauró los niveles de VEGF en el lavado broncoalveolar (p < 0,05) y disminuyó la expresión del receptor LTB4 (p < 0,001) y de NF-κB (p < 0,001), una diana downstream del LPS, en los leucocitos del parénquima pulmonar. Por último, redujo la producción de IL-8 por parte de los neutrófilos humanos tratados con LPS. Conclusión: En conclusión, el montelukast atenuó de manera eficaz tanto la inflamación pulmonar inducida por LPS en un modelo de ratón de SDRA como en neutrófilos humanos estimulados con LPS

Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells

PURPOSE. The aim of this study was to evaluate the influence of ovarian cancer cell lysates isolated from type I or type II ovarian cancer (OC) on the phenotype of monocyte-derived dendritic cells (Mo-DCs) and the cytokine profile. We also determined whether the Mo-DCs and tumor microenvironment, reflected by peritoneal fluid (PF) from type I or II ovarian cancer, could promote regulatory T cell (Tregs) differentiation from naive CD4+ lymphocytes in vitro. RESULTS. Our results show a significant role of the ovarian cancer microenvironment reflected by PF from type I or II OC in the inhibition of the DC differentiation process. Interestingly, the percentage of cells co-expressing CD45 and CD14 antigens in the cultures stimulated with PF from both type I and type II OC was higher than in the control. Furthermore, the percentage of cells expressing CD1a, i.e., a marker of immature DCs, was significantly reduced in the cultures stimulated with PF from type I and type II OC. The results obtained show that ovarian cancer type II lysates induce differentiation of monocytes into macrophage-like cells with a CD1a+/HLA-DR+/CD83− phenotype and significantly higher CD86/HLA-DR expression. We show that ovarian cancer type II Mo-DCs are able to prevent an immune response by release of IL-10, whereas OC type I Mo-DCs can promote the generation of Tregs. CONCLUSIONS. We demonstrate that each type of ovarian cancer can induce a unique phenotype of DCs and differentiation of Tregs, both associated with immune-suppressive function, which may be an obstacle while developing effective anticancer dendritic cell vaccination (AU)

No disponible

Alternaria alternata acts on human Monocyte-derived Dendritic cells to mediate Th2/Th17 polarisation

INTRODUCTION: Although the mechanism of asthma is not precisely understood in humans, clinical and epidemiological studies have offered a potential relationship between exposure to environmental fungi, such as Alternaria alternata (A. alternata) and the development and exacerbation of asthma. The aim of this project is to investigate the mechanisms of Th2 responses by A. alternata as a clinically relevant model for the environmental exposure. MATERIALS AND METHODS: Plastic adherent monocytes were cultured with granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) to convert these cells into Monocyte-derived Dendritic cells (MoDc) and then matured in the presence of Monocyte-Conditioned Medium (MCM) as the control group and MCM+ A. alternata extract as the inductive groups. RESULTS: The results indicated that the expression of CD14 decreased and CD83 and anti-human leukocyte antigen-DR (HLA-DR) increased in the inductive groups in comparison with the control group. More importantly, A. alternata inhibited IL-12 production by activated dendritic cells (DCs), and the DCs exposed to A. alternata enhanced the Th2 polarisation of CD4+ T cells. The production amount of IL-10 overcame IL-12 as well as Il-23 increased significantly, and hand in T cells the production of cytokines Interferon-γ (IFN-γ) decreased. However, both IL-17 and IL-4 increased (p < 0.05). Phagocytic activity in the inductive groups decreased significantly compared with the control group. CONCLUSION: The asthma-related environmental fungus A. alternata, with an effect on dendritic cells profile mediates TH2/TH17. Such immunodysregulation properties of causative environmental fungi may explain their strong relationship with human asthma and allergic diseases

No disponible

Ceramide-enriched LDL induces cytokine release through TLR4 and CD14 in monocytes. Similarities with electronegative LDL / La LDL enriquecida en ceramida induce la liberación de citoquinas a través de TLR4 y CD14 en monocitos. Similitudes con la LDL electronegativa

Introduction: In vitro ceramide-enriched LDL (CER-LDL) reproduces most of the properties of electronegative LDL (LDL(-)), a heterogeneous subfraction of LDL found in plasma. LDL(-) comprises several modifications of LDL and has an increased content in ceramide (CER). It promotes cytokine release in monocytes through CD14 and TLR4. CER-LDL also induces cytokine release in these cells but the mechanism is unknown. Aim To evaluate TLR4 andCD14 as the putative receptors involved in cytokine release induced by CER-LDL. Methods CER-LDL was obtained by incubating native LDL with CER-enriched liposomes. CER content in CER-LDL was assessed by thin layer chromatography of lipid extracts. CER-LDL and LDL(-) were incubated for 20 h with human monocytes in the presence or absence of a TLR4 signaling inhibitor. Both LDLs were also incubated with two human monocytic cell lines, normal and THP1 overexpressing CD14 (THP1-CD14) cells. The release of IL-6, IL-10 and MCP-1 was evaluated by ELISA in culture medium. Results: The release of IL-6, IL-10 and MCP-1 induced by CER-LDL in monocytes was inhibited by VIPER (90% inhibition), a specific TLR4 inhibitor. The cytokine release induced by contrast, the induction of cytokine release in THP1-CD14 was high and dependent on the CER content in LDL. Conclusion: CER-LDL induces IL-6, IL-10 and MCP-1 release through the activation of CD14 and TLR4 in monocytes, reproducing the behavior of LDL(-). The increased content of CER in LDL(-) is then related to the inflammatory action of LDL(-)

Introducción: La LDL enriquecida in vitro en ceramida (CER-LDL) reproduce varias características atribuidas a la LDL electronegativa (LDL(-)), subfracción heterogénea de LDL presente en circulación que induce la liberación de citoquinas en monocitos mediante CD14 y TLR4. La CER-LDL estimula también la liberación de citoquinas en monocitos, aunque el mecanismo se desconoce. Objetivo: Evaluar si CD14-TLR4 son receptores activados por la CER-LDL para inducir la liberación de citoquinas. Material y métodos: La CER-LDL se obtuvo in vitro mediante incubación de LDL nativa con liposomas enriquecidos en CER. El contenido en CER de la CER-LDL fue evaluado mediante cromatografía en capa fina. La CER-LDL y la LDL(−) fueron incubadas 20 h con monocitos humanos en presencia o ausencia de un inhibidor de la señalización de TLR4. También se incubaron con 2 líneas de monocitos humanos, THP1 y THP1, que sobreexpresan CD14 (THP1-CD14). Se evaluaron IL-6, IL-10 y MCP-1 en todos los sobrenadantes celulares mediante ELISA. Resultados: La liberación de IL-6, IL-10 y MCP-1 inducida por la CER-LDL en monocitos fue inhibida mediante VIPER (90% de inhibición), inhibidor específico de TLR4. Las citoquinas liberadas por la CER-LDL fueron escasas en THP1, células que presentan baja expresión de CD14. Las citoquinas liberadas por la CER-LDL en THP1-CD14 fueron superiores y dependientes del contenido en CER de la LDL. Conclusión: La LDL-CER induce IL-6, IL-10 y MCP-1 a través de la activación de CD14-TLR4 en monocitos, mimetizando a la LDL(-). La acción inflamatoria de la LDL(-) está relacionada con su contenido aumentado en CER

NOD2, CD14 and TLR4 mutations do not influence response to adalimumab in patients with Crohn’s disease: a preliminary report

Introduction: adalimumab is a recombinant fully-human monoclonal immunoglobulin (IgG1) antibody utilized in the treatment of Crohn´s disease. Unfortunately no clinical or genetic markers exist to predict response to anti-tumor necrosis factor-alpha (TNF) therapy. The aim of this study was to evaluate the association between selected genes involved in cytokine regulation and response to adalimumab treatment in Crohn’s disease. Methods: twenty-four patients with Crohn’s disease either naïve (n = 8) or had lost response or were unable to tolerate the chimeric anti-TNF antibody infliximab (n=16) were enrolled in the study. Patients were genotyped for main polymorphisms in NOD2, CD14 and TLR4 genes. Response to adalimumab treatment was defined as a decrease of Crohn’s disease activity index of at least 100 points or a closure of at least 50% of fistulas in case of fistulizing Crohn’s disease. Results: overall, 75% of patients did respond to treatment. However, no statistically significant association was found between any of the genotypes and the response to adalimumab. Conclusions: in our small study group no association between the studied polymorphisms and response to adalimumab was apparent. Systematic studies to search for genetic markers of response to anti-TNF therapy are necessary(AU)

Receptores implicados en la inducción de citoquinas promovida por la LDL electronegativa en monocitos / Receptors involved in cytokine induction promoted by electronegative LDL in monocytes

Introducción La LDL electronegativa (LDL[−]) es una fracción minoritaria de la LDL total que se encuentra en circulación y presenta diferentes propiedades inflamatorias, siendo una de las más relevantes la inducción de citoquinas en células endoteliales y mononucleares. Sin embargo, no se conoce el mecanismo por el cual la LDL(−) ejerce su acción (..) (AU)

Introduction Elecronegative LDL (LDL(−)) is a small fraction of the total circulating LDL and has different inflammatory properties, one of the most important being the induction of cytokines in endotelial cells and monocytes. However, the mechanism by which LDL (−) exercises its action at cellular level is not known. The objective of this study was to evaluate the receptors involved in LDL (−) binding in monocytes, and how the liberation of cytokines (..) (AU)

Role of metabolic endotoxemia in insulin resistance and obesity. The Buffering Efficiency Hypothesis

No disponible

Recent studies have shown that elevated concentrations of plasma lipopolysaccharide (LPS) constitute a metabolic mechanism enough for triggering insulin resistance, obesity and type 2 diabetes in animal models, and that high fat diets lead to increased plasma LPS concentrations through changes in the gut flora. We review here the LPS effects in metabolic processes in vitro. In humans, an altered innate immune system has also been associated with metabolic disorders such as insulin resistance, high endotoxemia markers (LBP, sCD14) and low LPS-neutralizing proteins (adiponectin, bactericidal permeability-increasing protein, a-defensins and lactoferrin). In fact, insulin resistance is well known to be associated with inflammation, with a decrease in innate immune efficiency and a reduction in the production of antimicrobial proteins. In this revision, we propose a new view according to which buffering efficiency of the innate (AU)

Hemorragia digestiva baja masiva en pacientes con enfemedad de Crohn / Major acute bleeding in patients with Crohn's disease

Objetivo: analizar la frecuencia de las hemorragias masivasen la EC e intentar determinar sus potenciales factores de riesgo(ambientales, propios de la enfermedad y genéticos).Material y métodos: se estudió de manera retrospectiva unacohorte de 174 pacientes –103 mujeres (59%) y 71 hombres(41%), edad media de 37 años– con EC, analizándose las hemorragiasdigestivas masivas que se habían producido en relacióncon su enfermedad. Se revisaron asimismo potenciales factoresde riesgo como hábito tabáquico, localización de la enfermedad ypresencia de mutaciones genéticas en CARD15, RTL-4 y CD14,entre otros.Resultados: tres pacientes (1,7%) presentaron una hemorragiadigestiva masiva que precisó intervención quirúrgica para suresolución. Esta indicación de cirugía supone el 3,4% de las cirugíasen relación con la EC. Todos los pacientes eran jóvenes y suenfermedad seguía un patrón inflamatorio y estaba localizada enel íleon. No se ha evidenciado asociación estadísticamente significativaentre las hemorragias digestivas masivas y los potencialesfactores de riesgo analizados.Conclusiones: la hemorragia digestiva baja masiva es unacomplicación poco común, aunque grave de la EC. Se trata habitualmentede pacientes con patrón inflamatorio de la enfermedady afectación ileal. Para su diagnóstico resulta clave la asociaciónde endoscopia y arteriografía, y su resolución suele ser quirúrgica

Objective: we aimed at evaluating the frequency of acute severebleeding in CD and its potential association to some risk factors,including clinical features of CD, environmental factors, andgenetic alterations.Material and methods: 174 consecutive patients with CD(103 female (59%) and 71 men (41%), with a mean age of 37years) were included. We analyzed all major acute lower gastrointestinal(GI) hemorrhage related to CD. Potential risk factors likesmoking, site of disease, and presence of gene mutations inCARD15, TLR-4, and CD14 were also analyzed.Results: three patients (1.7%) suffered from severe acute lowerGI bleeding. All patients required surgery to resolve their hemorrhage,and this indication represented 3.4% of all surgical proceduresrelated to CD. All three patients were young (< 25 years)and suffered ileal CD with inflammatory pattern (L1-B1 in the ViennaClassification). No relationship was found between acutebleeding and any of the potential risk factors evaluated.Conclusions: acute severe GI bleeding is a rare, but severecomplication in CD patients, and presents mainly in patients withinflammatory ileal disease. An association of endoscopy and arteriographyis necessary for diagnosis. Urgent surgery is usually requiredin these patients

Hemoglobinuria paroxística nocturna y gestación / Paroxsysmal nocturnal haemoglobinuria and pregnancy

La hemoglobinuria paroxística nocturna (HPN) es una forma de anemia hemolítica adquirida que afecta a la célula pluripotencial, activando el sistema de complemento y ocasionando un defecto en las células. Entre las características de esta enfermedad se encuentran un aumento en los procesos trombóticos, anemia y trombocitopenia. Describimos el caso de una paciente que tuvo un primer embarazo que finalizó en un aborto espontáneo y que, en su segunda gestación, desarrolló síntomas de HPN, cuyo empeoramiento obligó a finalizar el embarazo mediante cesárea a las 28 semanas de gestación. La literatura médica muestra que la HPN en la gestación puede aumentar los cuadros de tromboembolia, los abortos espontáneos, los partos pretérmino y la mortalidad perinatal. En los casos de parto vaginal, es recomendable realizar una analgesia epidural para evitar el estrés durante el parto (AU)