Effect of exogenous galectin-1 on leukocyte migration: modulation of cytokine levels and adhesion molecules

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Role of inflammatory mediators in priming, activation, and deformability of bovine neutrophils

Objective-To determine the capacity of inflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), platelet-activating factor (PAF), lipopolysaccharide (LPS), and leukotoxin to prime, activate, or alter deformability of adult bovine neutrophils.Sample Population-Blood collected from 5 healthy adult Holstein cows.Procedure-Isolated neutrophils or whole brood was incubated with TNF-alpha, IL-8, PAF, LPS, or leukotoxin, and neutrophil chemiluminescence, degranulation, deformability, shape change, CD11b expression, and size distribution was measured.Results-incubation with TNF-alpha, IL-8; PAF, and IFS primed neutrophils for oxygen radical release but caused minimal oxygen radical release by themselves. None of the inflammatory mediators induced degranulation. Incubation with TNF-alpha and PAF resulted in a decrease in neutrophil deformability and induced shape change in neutrophils. incubation with PAF consistently resulted in an increase in neutrophil size as measured by use of flow cytometry. Only IL-8 caused an increase in expression of CD11b by neutrophils.Conclusions and Clinical Relevance-Inflammatory mediators tested had minimal effects on neutrophil oxygen radical production or degranulation but did prime neutrophils for oxygen radical production. Incubation with PAF and TNF-alpha caused a decrease in neutrophil deformability and altered neutrophil shape and size. Results of our study indicate that PAF- and TNF-alpha-induced changes in neutrophil deformability and size may cause integrin- and setectin-independent trapping of neutrophils in the lungs of cattle with pneumonic pasteurellosis.

Human eosinophil adhesion and degranulation stimulated with eotaxin and RANTES in vitro: Lack of interaction with nitric oxide

Background: Airway eosinophilia is considered a central event in the pathogenesis of asthma. The toxic components of eosinophils are thought to be important in inducing bronchial mucosal injury and dysfunction. Previous studies have suggested an interaction between nitric oxide (NO) and chemokines in modulating eosinophil functions, but this is still conflicting. In the present study, we have carried out functional assays (adhesion and degranulation) and flow cytometry analysis of adhesion molecules (VLA-4 and Mac-1 expression) to evaluate the interactions between NO and CC-chemokines (eotaxin and RANTES) in human eosinophils. Methods: Eosinophils were purified using a percoll gradient followed byimmunomagnetic cell separator. Cell adhesion and degranulation were evaluated by measuring eosinophil peroxidase (EPO) activity, whereas expression of Mac-1 and VLA-4 was detected using flow cytometry. Results: At 4 h incubation, both eotaxin (100 ng/ml) and RANTES (1000 ng/ml) increased by 133% and 131% eosinophil adhesion, respectively. L-NAME alone (but not D-NAME) also increased the eosinophil adhesion, but the co-incubation of L-NAME with eotaxin or RANTES did not further affect the increased adhesion seen with chemokines alone. In addition, L-NAME alone (but not D-NAME) caused a significant cell degranulation, but it did not affect the CC-chemokine-induced cell degranulation. Incubation of eosinophils with eotaxin or RANTES, in absence or presence of L-NAME, did not affect the expression of VLA-4 and Mac-1 on eosinophil surface. Eotaxin and RANTES (100 ng/ml each) also failed to elevate the cyclic GMP levels above baseline in human eosinophils. Conclusion: Eotaxin and RANTES increase the eosinophil adhesion to fibronectin-coated plates and promote cell degranulation by NO-independent mechanisms. The failure of CC-chemokines to affect VLA-4 and Mac-1 expression suggests that changes in integrin function (avidity or affinity) are rather involved in the enhanced adhesion. © 2008 Lintomen et al; licensee BioMed Central Ltd.

Gene expression changes associated with myocarditis and fibrosis in hearts of mice with chronic chagasic cardiomyopathy

Chronic chagasic cardiomyopathy is a leading cause of heart failure in Latin American countries. About 30% of Trypanosoma cruzi-infected individuals develop this severe symptomatic form of the disease, characterized by intense inflammatory response accompanied by fibrosis in the heart.We performed an extensive microarray analysis of hearts from a mouse model of this disease and identified significant alterations in expression of ~12% of the sampled genes. Extensive up-regulations were associated with immune-inflammatory responses (chemokines, adhesion molecules, cathepsins, and major histocompatibility complex molecules) and fibrosis (extracellular matrix components, lysyl oxidase, and tissue inhibitor of metalloproteinase 1). Our results indicate potentially relevant factors involved in the pathogenesis of the disease that may provide newtherapeutic targets in chronic Chagas disease. © 2010 by the Infectious Diseases Society of America.

The role of cytokines in inflammatory bone loss

Chronic inflammatory processes close to bone often lead to loss of bone in diseases such as rheumatoid arthritis, periodontitis, loosened joint prosthesis and tooth implants. This is mainly due to local formation of bone resorbing osteoclasts which degrade bone without any subsequent coupling to new bone formation. Crucial for osteoclastogenesis is stimulation of mononuclear osteoclast progenitors by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) which induces their differentiation along the osteoclastic lineage and the fusion to mature, multinucleated osteoclasts. M-CSF and RANKL are produced by osteoblasts/ osteocytes and by synovial and periodontal fibroblasts and the expression is regulated by pro- and anti-inflammatory cytokines. These cytokines also regulate osteoclastic differentiation by direct effects on the progenitor cells. In the present overview, we introduce the basic concepts of osteoclast progenitor cell differentiation and summarize the current knowledge on cytokines stimulating and inhibiting osteoclastogenesis by direct and indirect mechanisms. © Informa Healthcare USA, Inc.

Potencial anti-inflamatório de Pyrenocine A isolada do Penicillium paxilli: abordagem profilática e terapêutica

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

Influência das células dendríticas das placas de peyer na modulação das repostas Th1/Th2 em camundongos infectados com Yersinia pseudotuberculosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Do progenitor cells from different tissue have the same phenotype?

The purpose of this work was to validate isolation methods for sheep mesenchymal stem cells (MSC) from different sources and to explore the hypothesis that MSC exhibit markers of the same phenotype independent from tissue source. Cells derived from ovine bone marrow, synovial membrane and adipose tissue were characterized using the following markers: CD44, CD45, CD11b and MHC-I. The isolated MSC were cultivated, went through osteogenic, chondrogenic and adipogenic differentiation, and were characterized by flow cytometry using mouse anti-ovine CD44, CD45 and MHC-I monoclonal antibody (mAb), and mouse anti-bovine CD11b mAb. Ovine MSC from all three sources differentiated under chondorgenic, osteogenic and adipogenic conditions. Also, MSC from the three tissues were found to express CD44 and MHC-I but lack of CD11b and CD45. The results obtained revealed that our isolation methods for the different tissues tested are valid and that MSC from the three sources studied have same immunophenotic characteristics. (C) 2014 Published by Elsevier Ltd. All rights reserved.

M-CSF Priming of Osteoclast Precursors Can Cause Osteoclastogenesis-Insensitivity, Which Can be Prevented and Overcome on Bone

Osteoclasts and macrophages share progenitors that must receive decisive lineage signals driving them into their respective differentiation routes. Macrophage colony stimulation factor M-CSF is a common factor; bone is likely the stimulus for osteoclast differentiation. To elucidate the effect of both, shared mouse bone marrow precursor myeloid blast was pre-cultured with M-CSF on plastic and on bone. M-CSF priming prior to stimulation with M-CSF and osteoclast differentiation factor RANKL resulted in a complete loss of osteoclastogenic potential without bone. Such M-CSF primed cells expressed the receptor RANK, but lacked the crucial osteoclastogenic transcription factor NFATc1. This coincided with a steeply decreased expression of osteoclast genes TRACP and DC-STAMP, but an increased expression of the macrophage markers F4/80 and CD11b. Compellingly, M-CSF priming on bone accelerated the osteoclastogenic potential: M-CSF primed cells that had received only one day M-CSF and RANKL and were grown on bone already expressed an array of genes that are associated with osteoclast differentiation and these cells differentiated into osteoclasts within 2 days. Osteoclastogenesis-insensitive precursors grown in the absence of bone regained their osteoclastogenic potential when transferred to bone. This implies that adhesion to bone dictates the fate of osteoclast precursors. Common macrophage-osteoclast precursors may become insensitive to differentiate into osteoclasts and regain osteoclastogenesis when bound to bone or when in the vicinity of bone. J. Cell. Physiol. 229: 210-225, 2014. (c) 2014 Wiley Periodicals, Inc.

Modulação da expressão de moléculas de superfície em macrófagos tratados com compostos isolados de microrganismos marinhos

Atualmente são conhecidas aproximadamente 10.000 substâncias do metabolismo secundário de invertebrados e microorganismos marinhos. Dentre os organismos marinhos estudados do ponto de vista químico e farmacológico, destacam-se, as esponjas, as ascídias, os briozoários e os octocorais. No entanto, pouco se sabe quanto ao potencial imunomodulador de compostos isolados de microrganismos marinhos, em especial daqueles isolados da costa brasileira. A propriedade anti-inflamatória de diferentes extratos brutos foi inicialmente avaliada pelo potencial destes compostos quanto à inibição da produção de óxido nítrico (NO) em linhagem de macrófagos, RAW 264.7. Posteriormente as amostras que se mostraram promissoras foram também avaliadas em relação ao potencial imunomodulador quanto a expressão de moléculas de superfície relacionadas migração (Mac-1 ou CD11b) e ativação celular (CD80 e CD86) em linhagens de macrófagos estimulados com LPS. Nossos resultados mostram que dentre as 289 amostras testadas apenas o extrato DLM33 e as substâncias Ma(M3%)J-MeOH e Dr(M3%)6-MeOH/H2O foram inicialmente considerados promissores quanto capacidade de inibir a síntese de NO por macrófagos. O extrato DLM33 foi capaz de de modular apenas a porcentagem de macrófagos positivos para CD80 na presença de LPS. No entanto, a substância Dr(M3%)6-MeOH/H2O não se mostrou eficiente quanto a modulação da expressão de moléculas de superfície Mac-1, CD80 e CD86. Surpreendentemente, a substância Ma(M3%)J-MeOH apresentou um potencial imunoestimulador quanto a expressão de Mac-1+/CD80+, mas não de CD86, em macrófagos sugerindo um possível efeito adjuvante desta substância. O efeito imunoestimulador da substância Ma(M3%)J-MeOH será futuramente investigado utilizando diferentes abordagens in vitro e in vivo para validar os resultados obtidos... (Resumo completo, clicar acesso eletrônico abaixo)

Produção de PGE2 por células dendríticas mediante fagocitose de células apoptóticas infectadas

A fagocitose de células apoptóticas é um processo dinâmico e de fundamental importância para homeostase dos tecidos após uma injúria. A fagocitose de células apoptóticas promove a síntese de mediadores anti-inflamatórios como PGE2, TGF-β e IL-10, podendo resultar na supressão da resposta imune do hospedeiro contra agentes infecciosos. Entretanto, um elegante estudo utilizando células apoptóticas infectadas demonstrou que a fagocitose destas células promove a geração não apenas de citocinas anti-inflamatórias como TGF-β mas também de IL-6 e IL-23, promovendo um efeito imunoestimulador, a diferenciação de células Th17. A atuação da PGE2 na imunidade adaptativa vem sendo investigada quanto à diferenciação e ativação de linfócitos Th1, Treg e Th17. Os resultados aqui apresentados demonstram que o protocolo de diferenciação de células dendríticas utilizado foi capaz de gerar em torno de 85% de CD imaturas evidenciado pela expressão de um perfil fenotípico CD11c+CD11b+MHCIIlowCD80lowCD86low. Quanto à produção de PGE2, a fagocitose de AC+PAMP por células dendríticas foi capaz de induzir níveis elevados deste mediador lipídico nas diferentes proporções de células apoptóticas utilizadas. Os níveis de PGE2 encontrados no sobrenadante de cultura foi proporção dependente evidenciando uma relação direta entre fagocitose de AC+PAMP e a produção de PGE2. A fim de mimetizar a cinética da carga bacteriana durante uma infecção, ou seja, inicialmente uma menor carga bacteriana que tende a aumentar conforme ocorre a colonização, os animais foram inoculados com alta (high - 106 UFC de E. coli) e baixa (low - 105 UFC de E. coli) cargas bacterianas, gerando desta forma o que chamamos de AC+PAMPhigh e AC+PAMPlow, respectivamente. Os resultados aqui apresentados demonstram que diante de uma alta carga bacteriana há uma maior produção dos mediadores

Efeito protetor da proteína anti-inflamatória Galectina-1 sobre o processo de uveíte induzida pelo inflamógeno lipopolissacarídeo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do uso de Selante de Fibrina derivado do veneno de serpente como arcabouço biológico de células tronco mesenquimais na regeneração óssea do fêmur de ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chitosan-alginate membranes accelerate wound healing

The purpose of this study was to evaluate the efficacy of chitosan-alginate membrane to accelerate wound healing in experimental cutaneous wounds. Two wounds were performed in Wistar rats by punching (1.5 cm diameter), treated with membranes moistened with saline solution (CAM group) or with saline only (SL group). After 2, 7, 14, and 21 days of surgery, five rats of each group were euthanized and reepithelialization was evaluated. The wounds/scars were harvested for histological, flow cytometry, neutrophil infiltrate, and hydroxyproline analysis. CAM group presented higher inflammatory cells recruitment as compared to SL group on 2nd day. On the 7th day, CAM group showed higher CD11b+ level and lower of neutrophils than SL group. The CAM group presented higher CD4+ cells influx than SL group on 2nd day, but it decreased during the follow up and became lower on 14th and 21st days. Higher fibroplasia was noticed on days 7 and 14 as well as higher collagenesis on 21st in the CAM group in comparison to SL group. CAM group showed faster reepithelialization on 7th day than SL group, although similar in other days. In conclusion, chitosan-alginate membrane modulated the inflammatory phase, stimulated fibroplasia and collagenesis, accelerating wound healing process in rats.

Chitosan-alginate membranes accelerate wound healing

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)