Endogenous protective effects of arachidonic acid epoxygenase metabolites, epoxyeicosatrienoic acids, in cardiovascular system / 生理学报

The morbidity and mortality of cardiovascular diseases are increasing annually, which is one of the primary causes of human death. Recent studies have shown that epoxyeicosatrienoic acids (EETs), endogenous metabolites of arachidonic acid (AA) via CYP450 epoxygenase, possess a spectrum of protective properties in cardiovascular system. EETs not only alleviate cardiac remodeling and injury in different pathological models, but also improve subsequent hemodynamic disturbances and cardiac dysfunction. Meanwhile, various studies have demonstrated that EETs, as endothelial-derived hyperpolarizing factors, regulate vascular tone by activating various ion channels on endothelium and smooth muscle, which in turn can lower blood pressure, improve coronary blood flow and regulate pulmonary artery pressure. In addition, EETs are protective in endothelium, including inhibiting inflammation and adhesion of endothelial cells, attenuating platelet aggregation, promoting fibrinolysis and revascularization. EETs can also prevent aortic remodeling, including attenuating atherosclerosis, adventitial remodeling, and aortic calcification. Therefore, it is clinically important to study the physiological and pathophysiological effects of EETs in the cardiovascular system to further elucidate the mechanisms, as well as provide new strategy for the prevention and treatment of cardiovascular diseases. This review summarizes the endogenous cardioprotective effects and mechanisms of EETs in order to provide a new insight for research in this field.

Research progress of eicosanoid metabolomics in cardiovascular diseases / 生理学报

Eicosanoids are oxidized derivatives of 20-carbon polyunsaturated fatty acids (PUFAs). In recent years, the role and mechanism of eicosanoids in cardiovascular diseases have attracted extensive attention. Substrate PUFAs including arachidonic acid are metabolized by cyclooxygenase, lipoxygenase, cytochrome P450 oxidase enzymes, or non-enzymatic auto-oxidation. Eicosanoid metabolomics is an effective approach to study the complex metabolic network of eicosanoids. In this review, we discussed the biosynthesis and functional activities of eicosanoids, the strategies of eicosanoid metabolomics, and applications and research progress of eicosanoid metabolomics in cardiovascular diseases, which might offer new insights and strategies for the treatment of cardiovascular diseases.

Effect of shear stress on eicosanoid metabolism in endothelial cells by metabolomics approach / 生理学报

The article aims to study the effect and mechanism of shear stress on eicosanoids produced by the metabolism of polyunsaturated fatty acids in endothelial cells. First, human umbilical vein endothelial cells were treated by control (Static), laminar shear stress (LSS) and oscillatory shear stress (OSS) for 6 h. Then the endothelial cells were incubated with fresh M199 medium for 3 h, and the cell culture medium was collected. Ultra-performance liquid chromatography-mass spectrometer was used to detect the level of eicosanoid metabolites secreted by endothelial cells. The results showed that under different shear stress, the level of eicosanoid metabolites were changed significantly. We found 10 metabolites were significantly up-regulated by OSS compared with those in LSS group, including PGD2, PGE2, PGF2α and PGJ2 produced by cyclooxygenase; 11-HETE, 15-HETE, 13-HDoHE produced by lipoxygenase or spontaneous oxidation; 12,13-EpOME, 9,10-EpOME, 9,10-DiHOME produced by cytochrome P450 oxidase and soluble epoxide hydrolase. The transcription levels of these up-regulated eicosanoids metabolic enzyme-related genes were also increased in vitro and in vivo. These results indicate that OSS may promote the increase of metabolites by up-regulating the transcription level of metabolic enzyme-related genes, which playing a key role in the development of atherosclerosis. This study reveals the effect of shear stress on eicosanoid metabolism in endothelial cells, which provides a novel supplement to the systems biology approach to study systemic hemodynamics.

Diverse characters of Brennan’s paw incision model regarding certain parameters in the rat / 대한통증학회지

BACKGROUND: Brennan’s rodent paw incision model has been extensively used for understanding mechanisms underlying postoperative pain in humans. However, alterations of physiological parameters like blood pressure and heart rate, or even feeding and drinking patterns after the incision have not been documented as yet. Moreover, though eicosanoids like prostaglandins and leukotrienes contribute to inflammation, tissue levels of these inflammatory mediators have never been studied. This work further investigates the antinociceptive effect of protein C after intra-wound administration. METHODS: Separate groups of Sprague–Dawley rats were used for quantitation of cyclooxygenase (COX) activity and leukotriene B4 level by enzyme-linked immunosorbent assay, as well as estimation of cardiovascular parameters and feeding and drinking behavior after paw incision. In the next part, rats were subjected to incision and 10 μg of protein C was locally administered by a micropipette. Both evoked and non-evoked pain parameters were then estimated. RESULTS: COX, particularly COX-2 activity and leukotriene B4 levels increased after incision. Hemodynamic parameters were normal. Feeding and drinking were affected on days 1 and 3, and on day 1, respectively. Protein C attenuated non-evoked pain behavior alone up to day 2. CONCLUSIONS: Based upon current observations, Brennan’s rodent paw incision model appears to exhibit a prolonged period of nociception similar to that after surgery, with minimal interference of physiological parameters. Protein C, which is likely converted to activated protein C in the wound, attenuated the guarding score, which probably represents pain at rest after surgery in humans.

Eicosanoids and cancer

Eicosanoids are 20-carbon bioactive lipids derived from the metabolism of polyunsaturated fatty acids, which can modulate various biological processes including cell proliferation, adhesion and migration, angiogenesis, vascular permeability and inflammatory responses. In recent years, studies have shown the importance of eicosanoids in the control of physiological and pathological processes associated with several diseases, including cancer. The polyunsaturated fatty acid predominantly metabolized to generate 2-series eicosanoids is arachidonic acid, which is the major n-6 polyunsaturated fatty acid found in animal fat and in the occidental diet. The three main pathways responsible for metabolizing arachidonic acid and other polyunsaturated fatty acids to generate eicosanoids are the cyclooxygenase, lipoxygenase and P450 epoxygenase pathways. Inflammation plays a decisive role in various stages of tumor development including initiation, promotion, invasion and metastasis. This review will focus on studies that have investigated the role of prostanoids and lipoxygenase-derived eicosanoids in the development and progression of different tumors, highlighting the findings that may provide insights into how these eicosanoids can influence cell proliferation, cell migration and the inflammatory process. A better understanding of the complex role played by eicosanoids in both tumor cells and the tumor microenvironment may provide new markers for diagnostic and prognostic purposes and identify new therapeutic strategies in cancer treatment.

Biomarcadores na rinite alérgica: qual a importância e potencial diagnóstico? / Biomarkers in allergic rhinitis: its importance and diagnostic potential

O objetivo deste estudo é apontar quais os novos potenciais marcadores biológicos na rinite alérgica (RA). Buscou-se nas bases de dados Scielo e PUBMED artigos com os descritores "Rinite Alérgica" e "Biomarcadores" ou "Citocinas" ou "Interleucinas" ou "Eicosanoides", bem como na língua inglesa. A perspectiva do uso de novos biomarcadores na rinite alérgica vem sendo pesquisada, visto que marcadores sensíveis e específicos da doença poderiam permitir rápido diagnóstico, avaliação do estágio da doença e estimação da resposta ao tratamento. Vários métodos para coleta de amostras não invasivos ou semi-invasivos nas vias aéreas oferecem a possibilidade de mensuração de uma grande quantidade de novos biomarcadores na RA. Como potenciais biomarcadores, a análise do perfil de citocinas nasais apresenta uma boa caracterização diagnóstica (IL-5 e IL-13), além da relação de severidade da doença (IL-9 e IL-17B). Como avaliação isolada, a dosagem sérica de Proteína da Célula de Clara (CC16) parece ter grande potencial, pois permite o diagnóstico e seus níveis estão inversamente relacionados com a severidade da doença. Além disso, a dosagem de FeNO vem como uma arma importante para predizer asma nos pacientes com RA.

Current analysis deals with the new potential biological markers in allergic rhinitis. Scielo and PUBMED databases were researched for articles through descriptors "Allergic rhinitis" and "Biomarkers" or "Cytokines" or "Interleukins" or "Eicosanoids", in English and Portuguese. The use of new biomarkers for allergic rhinitis is researched since sensitive and specific markers provide a quick diagnosis, assessment of the disease´s stage and estimates of treatment responses. Several invasive and semi-invasive methods for sample collection from the aerial pathways make possible the measurement of a great number of new biomarkers in allergic rhinitis. As potential biomarkers, the analysis of nasal cytokines offers a good diagnose (IL-5 and IL-13), coupled to the disease´s severity (IL-9 and IL-17B). As an isolated evaluation, serum dosage of Clara Cell Protein (CC16) seems to be highly promising since it favors diagnosis with inversely related levels for the disease´s severity. Further, FeNO dosage is an important tool to predict asthma in AR patients.

Epoxyeicosatrienoic acid activation moderates endothelial mesenchymal transition to reduce obstructive nephropathy

No abstract available.

Epoxyeicosatrienoic acid activation moderates endothelial mesenchymal transition to reduce obstructive nephropathy

No abstract available.

Mast Cells and Lipid Mediators

Human mast cells are potent effector cells in host defense mechanisms of innate and acquired immunity, including inflammatory diseases such as asthma and atherosclerosis. Mast cells originate from pluripotent hematopoietic progenitors in the bone marrow. Activation of mast cells by different stimuli triggers the release of a large range of mediators, including de novo synthesized eicosanoids which are highly biologically active lipid mediators. For the generation of lipid mediators, cytoplasmic lipid droplets have been shown to function as a major intracellular pool of arachidonic acid, the precursor for eicosanoids biosynthesis. The article summarizes current knowledge on mast cell biosynthesis of lipid mediator and the role in inflammation.

Liquid Chromatography-Mass Spectrometry-Based In Vitro Metabolic Profiling Reveals Altered Enzyme Expressions in Eicosanoid Metabolism

BACKGROUND: Eicosanoids are metabolites of arachidonic acid that are rapidly biosynthesized and degraded during inflammation, and their metabolic changes reveal altered enzyme expression following drug treatment. We developed an eicosanoid profiling method and evaluated their changes on drug treatment. METHODS: Simultaneous quantitative profiling of 32 eicosanoids in liver S9 fractions obtained from rabbits with carrageenan-induced inflammation was performed and validated by liquid chromatography-mass spectrometry coupled to anion-exchange solid-phase purification. RESULTS: The limit of quantification for the devised method ranged from 0.5 to 20.0 ng/mg protein, and calibration linearity was achieved (R 2>0.99). The precision (% CV) and accuracy (% bias) ranged from 4.7 to 10.3% and 88.4 to 110.9%, respectively, and overall recoveries ranged from 58.0 to 105.3%. Our method was then applied and showed that epitestosterone treatment reduced the levels of all eicosanoids that were generated by cyclooxygenases and lipoxygenases. CONCLUSIONS: Quantitative eicosanoid profiling combined with in vitro metabolic assays may be useful for evaluating metabolic changes affected by drugs during eicosanoid metabolism.

Eicosanoid Mediators in the Airway Inflammation of Asthmatic Patients: What is New?

Lipid mediators contribute to inflammation providing both pro-inflammatory signals and terminating the inflammatory process by activation of macrophages. Among the most significant biologically lipid mediators, these are produced by free-radical or enzymatic oxygenation of arachidonic acid named "eicosanoids". There were some novel eicosanoids identified within the last decade, and many of them are measurable in clinical samples by affordable chromatography-mass spectrometry equipment or sensitive immunoassays. In this review, we present some recent advances in understanding of the signaling by eicosanoid mediators during asthmatic airway inflammation. Eicosanoid profiling in the exhaled breath condensate, induced sputum, or their metabolites measurements in urine is complementary to the cellular phenotyping of asthmatic inflammation. Special attention is paid to aspirin-exacerbated respiratory disease, a phenotype of asthma manifested by the most profound changes in the profile of eicosanoids produced. A hallmark of this type of asthma with hypersensitivity to non-steroid anti-inflammatory drugs (NSAIDs) is to increase biosynthesis of cysteinyl leukotrienes on the systemic level. It depends on transcellular biosynthesis of leukotriene C₄ by platelets that adhere to granulocytes releasing leukotriene A₄. However, other abnormalities are also reported in this type of asthma as a resistance to anti-inflammatory activity of prostaglandin E₂ or a robust eosinophil interferon-γ response resulting in cysteinyl leukotrienes production. A novel mechanism is also discussed in which an isoprostane structurally related to prostaglandin E₂ is released into exhaled breath condensate during a provoked asthmatic attack. However, it is concluded that any single eicosanoid or even their complex profile can hardly provide a thorough explanation for the mechanism of asthmatic inflammation.

Imperatorin Suppresses Degranulation and Eicosanoid Generation in Activated Bone Marrow-Derived Mast Cells

Imperatorin has been known to exert many biological functions including anti-inflammatory activity. In this study, we investigated the inhibitory effects of imperatorin on the production of inflammatory mediators in mouse bone marrow-derived mast cells (BMMC). Imperatorin inhibited degranulation and the generation of eicosanoids (leukotriene C4 (LTC4) and prostaglandin D2 (PGD2)) in IgE/antigen (Ag)-stimulated BMMC. To elucidate the molecular mechanism involved in this process, we investigated the effect of imperatorin on intracellular signaling in BMMC. Biochemical analyses of the IgE/Ag-mediated signaling pathway demonstrated that imperatorin dramatically attenuated degranulation and the production of 5-lipoxygenase-dependent LTC4 and cyclooxygenase-2-dependent PGD2 through the inhibition of intracellular calcium influx/phospholipase Cgamma1, cytosolic phospholipase A2/mitogen-activated protein kinases and/or nuclear factor-kappaB pathways in BMMC. These results suggest that the effects of imperatorin on inhibition of degranulation and eicosanoid generation through the suppression of multiple steps of IgE/Ag-mediated signaling pathways would be beneficial for the prevention of allergic inflammation.

Phospholipid Remodeling and Eicosanoid Signaling in Colon Cancer Cells.

Phospholipid remodeling and eicosanoid synthesis are central to lipid-based inflammatory reactions. Studies have revealed that membrane phospholipid remodeling by fatty acids through deacylation/reacylation reactions increases the risk of colorectal cancers (CRC) by allowing the cells to produce excess inflammatory eicosanoids, such as prostaglandins, thromboxanes and leukotrienes. Over the years, efforts have been made to understand the lipid remodeling pathways and to design anti-cancer drugs targeting the enzymes of eicosanoid biosynthesis. Here, we discuss the recent progress in phospholipid remodeling and eicosanoid biosynthesis in CRC.

Anopheles gambiae eicosanoids modulate Plasmodium berghei survival from oocyst to salivary gland invasion

Eicosanoids affect the immunity of several pathogen/insect models, but their role on the Anopheles gambiae response to Plasmodium is still unknown. Plasmodium berghei-infected mosquitoes were injected with an eicosanoid biosynthesis inhibitor, indomethacin (IN), or a substrate, arachidonic acid (AA), at day 7 or day 12 post-infection (p.i.). Salivary gland invasion was evaluated by sporozoite counts at day 21 p.i. IN promoted infection upon sporozoite release from oocysts, but inhibited infection when sporozoites were still maturing within the oocysts, as observed by a reduction in the number of sporozoites reaching the salivary glands. AA treatment had the opposite effect. We show for the first time that An. gambiae can modulate parasite survival through eicosanoids by exerting an antagonistic or agonistic effect on the parasite, depending on its stage of development.

Airborne agricultural particulate matter induces inflammatory cytokine secretion by respiratory epithelial cells: Mechanisms of regulation by eicosanoid lipid signal mediators.

The purpose of this study was to elucidate the mechanism of the airborne poultry dust (particulate matter, PM)-induced respiratory tract inflammation, a common symptom in agricultural respiratory diseases. The study was based on the hypothesis that poultry PM would induce the release of inflammatory cytokine interleukin-8 (IL-8) by respiratory epithelial cells under the upstream regulation by cytosolic phospholipase A2 (cPLA2) activation and subsequent formation of cyclooxygenase (COX)- and lipoxygenase (LOX)-catalyzed arachidonic acid (AA) metabolites (eicosanoids). Human lung epithelial cells (A549) in culture were treated with the poultry PM (0.1-1.0 mg) for different lengths of time, following which PLA2 activity, release of eicosanoids and secretion of IL-8 in cells were determined. Poultry PM (1.0 mg/ml) caused a significant activation of PLA2 in a time-dependent manner (15-60 min), which was significantly attenuated by the calcium-chelating agents, cPLA2-specific inhibitor (AACOCF3) and antioxidant (vitamin C) in A549 cells. Poultry PM also significantly induced the release of COX- and LOX-catalyzed eicosanoids (prostaglandins, thromboxane A2 and leukotrienes B4 and C4) and upstream activation of AA LOX in the cells. Poultry PM also significantly induced release of IL-8 by the cells in a dose- and time-dependent manner, which was significantly attenuated by the calcium chelating agents, antioxidants and COX- and LOX-specific inhibitors. The current study for the first time revealed that the poultry PM-induced IL-8 release from the respiratory epithelial cells was regulated upstream by reactive oxygen species, cPLA2-, COX- and LOX-derived eicosanoid lipid signal mediators.

Receptores envolvidos na produção de citocinas e eicosanóides por monócitos e neutrófilos humanos em resposta ao Paracoccidioides brasiliensis / Receptors involved in the release of cytokines and eicosanoids by human neutrophils and monocytes in response to Paracoccidioides brasiliensis

O Paracoccidioides brasiliensis é o agente etiológico da paracoccidioidomicose a micose sistêmica de maior prevalência na América Latina. Dentre os vários mecanismos da resposta inata contra esse fungo, os envolvendo as células fagocitárias desempenham papel central na contenção do processo infeccioso, com destaque para a participação na atividade fungicida e modulação da resposta inflamatória. As funções das células fagocitárias contra os diversos microrganismos, incluindo os fungos, são iniciadas a partir de mecanismos de ativação dessas células, gerados após o reconhecimento dos mesmos por receptores de reconhecimento de estruturas moleculares padrões (PRRs) que reconhecem estruturas moleculares compartilhadas por determinados grupos de microrganismos, os chamados padrões moleculares associados à patógenos (PAMPS). Nosso estudo objetivou estudar a participação dos receptores TLR2, TLR4, receptor de manose (MR) e dectina-1, na produção de citocinas pró e anti-inflamatórias e dos eicosanóides PGE2 e LTB4, por monócitos e neutrófilos humanos em resposta a cepas de P. brasiliensis de alta (Pb18) e baixa virulência (Pb265). Verificamos que as duas cepas do fungo, mas principalmente a Pb265 são capazes de induzir a produção de TNF-alfa por monócitos. TLR2 e TLR4 foram os receptores que se mostraram mais envolvidos nesse processo. Adicionalmente, mostramos a capacidade de essas células liberarem IL-12 em resposta ao fungo, sendo os maiores níveis detectados para a cepa Pb265 e ocorrendo um importante papel do TLR4 e MR. Altos níveis de IL-10 também foram detectados, principalmente em resposta à cepa Pb18 para a qual houve um envolvimento do TLR2 e do MR. Para a cepa 265, o receptor de maior envolvimento foi o TLR2...

Paracoccidioides brasiliensis is the etiological agent of paracoccidiodomycosis, the most prevalent deep mycosis in Latin America. During the innate immune response of the host against this fungus, phagocytic cells play an essential role, highlighting their participation in fungicidal activity and modulation of the inflammatory response. The functions of phagocytic cells against various microorganisms, including fungi, are initiated by the recognition of patterns molecular structures, shared by a group of microorganisms, called pathogen-associated molecular patterns (PAMPs), by pattern recognizing receptors (PRRs) expressed by these cells. In this study, we assessed the involvement of the PRRs : TLR2, TLR4, mannose receptor (MR) and dectin-1, in the production of pró and anti-inflammatory cytokines and the eicosanoid PGE2 and LTB4, by human monocytes and neutrophils in response to high- (Pb18) and a low- (Pb265) virulence strain of P. brasiliensis. We showed that monocytes produce TNF-alpha and IL-12 in response to both strains, but with higher levels to Pb 265. TLR2 and TLR4 were the main receptors involved in TNF-alpha production, while for IL-12, the participation of TLR4 and MR was detected. High levels of IL-10 were also observed, mainly in response to Pb18, with involvement of TLR2 and MR. For Pb265, the receptor responsible was TLR2. Boths strains were able to induce PGE2 and LTB4 by monocytes. However, none of the studied receptors was shown to be involved in this production. Neutrophils did not produce TNF-alpha in response to both strains. On the other hand, these cells produce IL-12, mainly in response to Pb265, with participation of TLR2, dectin-1 and TLR4. These cells also produce L-10, whose levels were higher for Pb18 with involvement of TLR2 and MR and only TLR2 for Pb265...

Corpúsculos lipídicos e eicosanoides nos momentos iniciais da infecção com leishmania infantum chagasi / Eicosanoids and lipid bodies in the early stages of infection with Leishmania infantum chagasi

Corpúsculos lipídicos são organelas citoplasmáticas envolvidas na produção de eicosanoides em leucócitos. Eicosanoides como as prostaglandinas têm sido envolvidos no controle da resposta inflamatória e imunológica. A saliva de Lutzomyia longipalpis participa do estabelecimento e desenvolvimento da doença pela modulação das respostas hemostática, imunológica e inflamatória do hospedeiro favorecendo a infecção. Entretanto, o papel dos eicosanoides nos momentos iniciais da infecção por Leishmania ainda não foi esclarecido, assim como a participação da saliva neste contexto. Aqui, nós investigamos o papel dos eicosanoides induzidos pela saliva de L. longipalpis e produzidos pela Leishmania infantum chagasi na infecção. O sonicado de glândula salivar (SGS) de L. longipalis induziu um aumento no número de CLs em macrófagos de maneira dose e tempo dependente, o qual esteve correlacionado com o aumento de PGE2 nos sobrenadante de cultura. As enzimas COX-2 e PGE- intase foram co-localizadas nos CLs induzidos pela saliva e a produção de PGE2 foi reduzida pelo tratamento com NS-398, um inibidor de COX-2. Nós verificamos que o SGS rapidamente estimulou a fosforilação de ERK-1/2 e PKC-α e a inibição farmacológica dessas vias inibiu a produção de PGE2 pelos macrófagos estimulados com SGS. Em seguida, nós avaliamos o efeito da saliva de L. longipalpis sobre a produção de eicosanoides durante a infecção por L. i. chagasi no modelo peritoneal murino. Nós observamos que a saliva aumentou a viabilidade intracelular de L. i. chagasi tanto em neutrófilos como em neutrófilos recrutados para a cavidade peritoneal. As células recrutadas para cavidade peritoneal apresentaram maiores níveis da relação PGE2/LTB4 e o pré-tratamento com NS-398 reverteu o efeito da saliva sobre a viabilidade intracelular dos parasitas. Parasitas como Leishmania são capazes de produzir PGs utilizando uma maquinaria enzimática própria. Neste estudo nós descrevemos a dinâmica de formação e a distribuição celular dos CLs em L. i. chagasi bem como a participação desta organela na produção de PGs. A quantidade de CLs aumentou durante a metaciclogênese assim como a expressão de PGF2α sintase (PGFS), sendo esta enzima co-localizada nos CLs. A adição de ácido araquidônico AA à cultura de L. i. chagasi aumentou a quantidade de CLs por parasita, bem como a secreção de PGF2α. A infecção com as diferentes formas de L. i. chagasi não foi capaz de estimular a formação de CLs na célula hospedeira. Por outro lado, os parasitas intracelulares apresentaram maiores quantidades de CLs. A infecção estimulou uma rápida expressão de COX-2, mas não foi detectado aumento na produção de PGF2α nos sobrenadantes. Por fim, nós verificamos a presença do receptor de PGF2α (FP) nos vacúolos parasitóforos de macrófagos infectados com L. i. chagasi. O prétratamento das células com um antagonista do receptor FP inibiu os índices de infecção de forma dose-dependente. Em conjunto, nossos dados apontam que os eicosanoides desempenham um papel crucial para evasão da resposta imune durante os momentos iniciais da infecção por L. i. chagasi com diferentes contribuições do parasita, do vetor e da célula hospedeira neste contexto.

Diffuse Cutaneous Leishmaniasis (LCD) is a rare clinical manifestation of Leishmaniasis, characterized by a number of macrophages heavily parasitized and low inflammatory reaction. In Brazil, Leishmania (Leishmania) amazonensis is the main specie involved in LCD cases. It has been described that the exposure and recognition of phosphatidylserine (PS) on the surface of apoptotic cells phagocytosed by macrophages is a macrophage deactivation mechanism dependent on TGF-pi and PGE2 (Fadok et al. 1998). Morover, it was demonstrated by Barcinski and colleagues that L. amazonensis amastigotes expose PS on its surface, in a mechanism called ’’Apoptotic Mimicry." In this context, our goal was to investigate the exposure of PS on the surface of L. amazonensis isolates obtained from LCD patients and its role during the infection of macrophages. Initially, peritoneal macrophages from FI mice (BALB/c x C57BL/6) stimulated with thioglycolate were infected with different L. amazonensis strains isolated from patients with Localized Cutaneous Leishmaniasis (LCL) or LCD. The exposure of PS on the surface of amastigotes was determined by flow cytometry using staining to annexin V and propidium iodide. Isolates from LCD patients showed higher PS exposure than the isolates from LCL patients 24 hours after infection. Then, we evaluated whether the differences of PS exposure in amastigotes would correlate with the infectivity of different isolates. Percentage of infected macrophages and infection index were higher in cultures using amastigotes from LCD patients compared to the ones infected with amastigotes from LCL cases. Furthermore, cultures infected with LCD isolates showed no difference to the LCL isolates regarding TGF>pl and nitric oxide production, suggesting that other immuneregulatory mechanisms are involved in this process...

Exhaled breath condensate analysis in chronic obstructive pulmonary disease.

The increasing focus on airway inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has led to development and evolution of tools to measure it. Direct assessment of airway inflammation requires invasive procedures, and hence, has obvious limitations. Non-invasive methods to sample airway secretions and fluids offer exciting prospects. Analysis of exhaled breath condensate (EBC) is rapidly emerging as a novel non-invasive approach for sampling airway epithelial lining fluid and offers a convenient tool to provide biomarkers of inflammation. It has definite advantages that make it an attractive and a feasible option. It is a source of mediators and molecules that are the causes or consequences of the inflammatory process. Measurement of such markers is increasingly being explored for studying airway inflammation qualitatively and quantitatively in research studies and for potential clinical applications. These biomarkers also have the potential to develop into powerful research tools in COPD for identifying various pathways of pathogenesis of COPD that may ultimately provide specific targets for therapeutic intervention. The EBC analysis is still an evolving noninvasive method for monitoring of inflammation and oxidative stress in the airways. The limited number of studies available on EBC analysis in COPD have provided useful information although definite clinical uses are yet to be defined. Evolving technologies of genomics, proteomics, and metabonomics may provide deeper and newer insights into the molecular mechanisms underlying the pathogenesis of COPD.

O papel dos ácidos graxos essenciais no perfil de eicosanoides e sua repercussão na resposta imune / The role of essential fatty acids on the eicosanoids profile and its impact on immune response

Dietary lipids, especially essential fatty acids are subject of great interest to the scientific community due to their role in the of eicosanoids formation.The purpose of this review was to investigate the role of essential fatty acidsin the profile of eicosanoids synthesized in the body and its effect on immune response, specifically in inflammatory diseases and autoimmune diseases. The omega-3 and omega-6 families of fatty acids are structurally and functionally distinct, leading to the formation of metabolites with different physiological activities. Through the action of specific enzymes, cyclooxygenase and lipoxygenase, linoleic acid is a precursor of 2-series prostaglandins and 4-series leukotrienes, which are highly active mediators of inflammation, whereas ?-linolenic acid produce the 3-seriesprostaglandins and 5-series leukotrienes, compounds with anti-inflammatory action in the body. These compounds are involved in the development of several infl ammatory and autoimmune diseases, and theproportion in which the essential omega-3 and omega-6 fatty acids are present in the diet will defi ne the profile of eicosanoids generated, thus contributing to the progression or control of diseases such as asthma, rheumatoid arthritis and atherosclerosis. The lack of specifi c benchmarksfor the consumption of omega-3 and omega-6 fatty acids for each disease and limited data about the concentration of different fatty acids in food are challenges that must be overcome in future research.

Los lípidos de la dieta, especialmente los ácidos grasos esenciales, han representado tema de gran interés para la comunidad científica debido a su papel en la formación de eicosanoides. El objetivo de esta revisión fue investigar el papel de los ácidos grasos esenciales en el perfil deeicosanoides sintetizados en el organismo y suefecto sobre la respuesta inmune, específicamenteen los cuadros inflamatorios y enfermedades autoinmunes. Las familias de los ácidos grasos omega-3 y omega-6 son estructuralmente y funcionalmente distintas, y conducen a la formación de metabolitos con actividad fisiológica diferente. Por medio de la acción de enzimas específicas, la ciclooxigenasas y lalipoxigenasas, el ácido linoleico es un precursor de las prostaglandinas de la serie 2 y leucotrienosde la serie 4, que son muy activos mediadores de la inflamación, mientras que el ácido ?-linolénico forma prostaglandinas de la serie 3 y leucotrienos de la serie 5, compuestos conacción anti inflamatoria en el organismo. Estos compuestos están involucrados en el desarrollo de varias enfermedades inflamatorias y autoinmunes, y la proporción en que los ácidos grasos esenciales, omega-3 y omega-6, aparecenen la dieta define el perfil de eicosanoides generados, lo que contribuye al progreso o alcontrol de enfermedades como asma, artritis reumatoide y ateriosclerosis. La falta deparámetros de consumo de ácidos grasosomega-3 y omega-6 específicos para cadaenfermedad y los datos limitados sobre la concentración de los diferentes ácidos grasos en alimentos son desafios que deben ser superados en futuras investigaciones.

Os lipídios dietéticos, em especial os ácidos graxos essenciais, têm representado tema de grande interesse para a comunidade científica devido ao seu papel na formação de eicosanoides. Diante disso, o objetivo da presente revisão foi investigar o papel desses ácidos graxos no perfil de eicosanoides sintetizados no organismo e sua repercussão na resposta imune, especificamente em quadros inflamatórios e de doenças autoimunes. As famílias de ácidos graxos ômega-6 e ômega-3 são estruturalmente e funcionalmente distintas, levando à formação de metabólitos com atividade fisiológica diferente. Por meio da ação de enzimas específicas, cicloxigenases e lipoxigenases, ácido linoléico é precursor de prostaglandinas da série 2 e leucotrienos da série 4, os quais são mediadores altamente ativos na inflamação, enquanto que, o ácido ?-linolênicoforma prostaglandinas da série 3 e leucotrienosda série 5, compostos com ação anti-inflamatória no organismo. Tais compostos estão envolvidos no desenvolvimento de várias doenças de natureza inflamatória e auto-imune, e a proporção com que os ácidos graxos essencia isômega-6 e ômega-3 aparecem na dieta definirá o perfil de eicosanoides gerados, contribuindo para a progressão ou o controle de doenças como asma, artrite reumatóide e aterosclerose. A ausência de parâmetros de referência de consumo de ácidos graxos essenciais específicos para cada enfermidade e a limitação de informações relativas à concentração dos diferentes ácidos graxos em alimentos representam desafios que devem ser superados com pesquisas futuras.