Platelet-activating factor and protease-activated receptor 2 cooperate to promote neutrophil recruitment and lung inflammation through nuclear factor-kappa B transactivation.

Although it is well established that platelet-activated receptor (PAF) and protease-activated receptor 2 (PAR2) play a pivotal role in the pathophysiology of lung and airway inflammatory diseases, a role for a PAR2-PAFR cooperation in lung inflammation has not been investigated. Here, we investigated the role of PAR2 in PAF-induced lung inflammation and neutrophil recruitment in lungs of BALB/c mice. Mice were pretreated with the PAR2 antagonist ENMD1068, PAF receptor (PAFR) antagonist WEB2086, or aprotinin prior to intranasal instillation of carbamyl-PAF (C-PAF) or the PAR2 agonist peptide SLIGRL-NH2 (PAR2-AP). Leukocyte infiltration in bronchoalveolar lavage fluid (BALF), C-X-C motif ligand 1 (CXCL)1 and CXCL2 chemokines, myeloperoxidase (MPO), and N-acetyl-glycosaminidase (NAG) levels in BALF, or lung inflammation were evaluated. Intracellular calcium signaling, PAFR/PAR2 physical interaction, and the expression of PAR2 and nuclear factor-kappa B (NF-КB, p65) transcription factor were investigated in RAW 264.7 cells stimulated with C-PAF in the presence or absence of ENMD1068. C-PAF- or PAR2-AP-induced neutrophil recruitment into lungs was inhibited in mice pretreated with ENMD1068 and aprotinin or WEB2086, respectively. PAR2 blockade impaired C-PAF-induced neutrophil rolling and adhesion, lung inflammation, and production of MPO, NAG, CXCL1, and CXCL2 production in lungs of mice. PAFR activation reduced PAR2 expression and physical interaction of PAR2 and PAFR; co-activation is required for PAFR/PAR2 physical interaction. PAR2 blockade impaired C-PAF-induced calcium signal and NF-κB p65 translocation in RAW 264.7 murine macrophages. This study provides the first evidence for a cooperation between PAFR and PAR2 mediating neutrophil recruitment, lung inflammation, and macrophage activation.

Protease-activated receptor 2 enhances innate and inflammatory mechanisms induced by lipopolysaccharide in macrophages from C57BL/6 mice.

OBJECTIVE: This study was conducted to investigate the effects of the synthetic PAR2 agonist peptide (PAR2-AP) SLIGRL-NH2 on LPS-induced inflammatory mechanisms in peritoneal macrophages. METHODS: Peritoneal macrophages obtained from C57BL/6 mice were incubated with PAR2-AP and/or LPS, and the phagocytosis of zymosan fluorescein isothiocyanate (FITC) particles; nitric oxide (NO), reactive oxygen species (ROS), and cytokine production; and inducible NO synthase (iNOS) expression in macrophages co-cultured with PAR-2-AP/LPS were evaluated. RESULTS: Co-incubation of macrophages with PAR2AP (30 µM)/LPS (100 ng/mL) enhanced LPS-induced phagocytosis; production of NO, ROS, and the pro-inflammatory cytokines interleukin (IL)-1ß, tumour necrosis factor (TNF)-α, IL-6, and C-C motif chemokine ligand (CCL)2; and iNOS expression and impaired the release of the anti-inflammatory cytokine IL-10 after 4 h of co-stimulation. In addition, PAR2AP increased the LPS-induced translocation of the p65 subunit of the pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) and reduced the expression of inhibitor of NF-κB. CONCLUSION: This study provides evidence of a role for PAR2 in macrophage response triggered by LPS enhancing the phagocytic activity and NO, ROS, and cytokine production, resulting in the initial and adequate macrophage response required for their innate response mechanisms.

Blockade of protease-activated receptor 2 attenuates allergenmediated acute lung inflammation and leukocyte recruitment in mice.

Protease-activated receptor (PAR)2 has been implicated in mediating allergic airway inflammation.We investigate the role of PAR2 in lung inflammation and neutrophil and eosinophil recruitment into the lungs in amousemodel of shortterm acute allergic inflammation. Allergic lung inflammation was induced in sensitized BALB/c mice through intranasal instillations of ovalbumin (OVA), and mice were pretreated with the PAR2 antagonist ENMD1068 or with the PAR2-activating peptide (PAR2-AP) 1 hour before each OVA challenge. Bronchoalveolar lavage fluid (BALF) was collected, and the lungs, trachea and lymph nodes were removed after the last challenge to analyze the airway inflammation. PAR2 blockade reduced OVA-induced eosinophil and neutrophil counts, CXCL1, CCL5, amphiregulin, and interleukin (IL)-6 and 13 levels.Moreover, PAR2 blockade reduced OVA-induced PAR2 expression in cells present in BALF 2 hour after OVA challenge, and PAR2-AP acted synergistically with OVA promoting eosinophil recruitment intoBALF and increased IL-4 and IL-13 levels in lymph nodes. Conversely, PAR2 blockade increased IL- 10 levels when compared with OVA-treated mice. Our results provide evidence for a mechanism by which PAR2 meditates acute lung inflammation triggered by multiple exposures to allergen through a modulatory role on cytokine production and vascular permeability implicated in the lung diseases such as asthma.

Caryocar villosum attenuates inflammation by inhibiting CXCL1 activation and peripheral hyperalgesia through opioid pathway modulation / Caryocar villosum atenua a inflamação ao inibir a ativação de CXCL1 e a hiperalgesia periférica por meio da modulação da via opioide

The oil of Caryocar villosum is used in Amazonian folk medicine to treat pain and inflammatory conditions. So, we assessed the anti-inflammatory and antinociceptive properties of the ethanolic extract obtained from the fruit peels of this species. The acetic acid-induced writhing, carrageenan-induced mechanical hyperalgesia, formalin, carrageenan-induced paw edema and carrageenan-induced peritonitis tests were used on mice. The C. villosum ethanolic extract significantly inhibited the number of abdominal writhes, mechanical hyperalgesia and paw licking time in the second phase of the formalin test. At a dose of 300 mg kg-1, the extract also significantly reduced the volume of edema formed in the late phase and reduced the recruitment of leukocytes and neutrophils in the peritoneal cavity, as well as CXCL1 chemokine levels. It is suggested that the extract attenuates the leukocyte recruitment by inhibiting the CXCL1 activation. The peripheral antinociceptive activity occured through opioid pathway modulation because pretreatment with C. villosum ethanolic extract reversed the naltrexone-induced antinociception.(AU)

O óleo de Caryocar villosum é usado na medicina popular amazônica para tratar dores e condições inflamatórias. Assim, avaliamos as propriedades antiinflamatórias e antinociceptivas do extrato etanólico obtido das cascas dos frutos desta espécie. Os testes de contorções induzidas por ácido acético, hiperalgesia mecânica induzida por carragenina, formalina, edema de pata induzido por carragenina e peritonite induzida por carragenina foram usados em camundongos. O extrato etanólico de C. villosum obtido das cascas dos frutos inibiu significativamente o número de contorções abdominais, a hiperalgesia mecânica e o tempo de lambida da pata na segunda fase do teste de formalina. Na dose de 300 mg kg-1, o extrato também reduziu significativamente o volume de edema formado na fase tardia e reduziu o recrutamento de leucócitos e neutrófilos na cavidade peritoneal, bem como os níveis de quimiocina CXCL1. Sugere-se que o extrato atenua o recrutamento de leucócitos por meio da inibição da ativação de CXCL1. A atividade antinociceptiva periférica ocorre por meio da modulação da via opioide pois o pré-tratamento com o extrato etanólico de C. villosum reverteu a antinocicepção induzida pela naltrexona.(AU)

Pharmacological blockade of protease-Activated Receptor 2 improves airway remodeling and lung inflammation in experimental allergic asthma

Abstract Protease-activated receptors (PARs) are metabotropic G-protein-coupled receptors that are activated via proteolytic cleavage of a specific sequence of amino acids in their N-terminal region. PAR2 has been implicated in mediating allergic airway inflammation. This study aims to study the effect of PAR2 antagonist ENMD1068in lung inflammation and airway remodeling in experimental asthma. Allergic lung inflammation was induced in sensitized BALB/c mice through intranasal instillations of ovalbumin (OVA), and mice were pretreated with ENMD1068 1 hour before each OVA challenge. Bronchoalveolar lavage fluid (BALF) was collected, and the lungs were removed at different time intervals after OVA challenge to analyze inflammation, airway remodeling and airway hyperresponsiveness. Ovalbumin promoted leukocyte infiltration into BALF in a PAR2-dependent manner. ENMD1068 impaired eosinophil peroxidase (EPO) and myeloperoxidase (MPO) activity in the lung parenchyma into BALF and reduced the loss of dynamic pulmonary compliance, lung resistance in response to methacholine, mucus production, collagen deposition and chemokine (C-C motif) ligand 5 expression compared to those in OVA-challenged mice. We propose that proteases released after an allergen challenge may be crucial to the development of allergic asthma in mice, and PAR2 blockade may be useful as a new pharmacological approach for the treatment of airway allergic diseases.

LyeTx I-b Peptide Attenuates Tumor Burden and Metastasis in a Mouse 4T1 Breast Cancer Model.

Cationic anticancer peptides have exhibited potent anti-proliferative and anti-inflammatory effects in neoplastic illness conditions. LyeTx I-b is a synthetic peptide derived from Lycosa erythrognatha spider venom that previously showed antibiotic activity in vitro and in vivo. This study focused on the effects of LyeTxI-b on a 4T1 mouse mammary carcinoma model. Mice with a palpable tumor in the left flank were subcutaneously or intratumorally injected with LyeTx I-b (5 mg/kg), which significantly decreased the tumor volume and metastatic nodules. Histological analyses showed a large necrotic area in treated primary tumors compared to the control. LyeTxI-b reduced tumor growth and lung metastasis in the 4T1 mouse mammary carcinoma model with no signs of toxicity in healthy or cancerous mice. The mechanism of action of LyeTx I-b on the 4T1 mouse mammary carcinoma model was evaluated in vitro and is associated with induction of apoptosis and cell proliferation inhibition. Furthermore, LyeTx I-b seems to be an efficient regulator of the 4T1 tumor microenvironment by modulating several cytokines, such as TGF-ß, TNF-α, IL-1ß, IL-6, and IL-10, in primary tumor and lung, spleen, and brain. LyeTx I-b also plays a role in leukocytes rolling and adhesion into spinal cord microcirculation and in the number of circulating leukocytes. These data suggest a potent antineoplastic efficacy ofLyeTx I-b.

Protease-activated receptor 4 plays a role in lipopolysaccharide-induced inflammatory mechanisms in murine macrophages.

The role of protease-activated receptor (PAR)4 in thrombin-induced platelet aggregation has been studied, and PAR4 blockade is thought to be useful as a new and promising approach in antiplatelet therapy in humans. In recent years, studies have been conducted to clarify the role of PAR4 in the host defense against invading microorganisms and pathogen-induced inflammation; however, to date, the role of PAR4 in mediating the LPS-induced inflammatory repertoire in macrophages remains to be elucidated. Here, we investigated the effects of the synthetic PAR4 agonist peptide (PAR4-AP) AYPGKF-NH2 on the phagocytosis of zymosan-FITC particles; NO, ROS, and iNOS expression; and cytokine production in C57/BL6 macrophages cocultured with PAR4-AP/LPS. The PAR4-AP impaired LPS-induced and basal phagocytosis, which was restored by pharmacological PAR4 blockade. Coincubation with the PAR4-AP/LPS enhanced NO and ROS production and iNOS expression; decreased IL-10, but not TNF-α, in the culture supernatant; and increased translocation of the p65 subunit of the proinflammatory gene transcription factor NF-κ-B. Our results provide evidence for a complex mechanism and new approach by which PAR4 mediates the macrophage response triggered by LPS through counter-regulating the phagocytic activity of macrophages and innate response mechanisms implicated in the killing of invading pathogens.

Correction to: A role for mast cells and mast cell tryptase in driving neutrophil recruitment in LPS-induced lung inflammation via protease-activated receptor 2 in mice.

The original article can be found online.

A role for mast cells and mast cell tryptase in driving neutrophil recruitment in LPS-induced lung inflammation via protease-activated receptor 2 in mice.

OBJECTIVE: This study aims to investigate the role of protease-activated receptor (PAR) 2 and mast cell (MC) tryptase in LPS-induced lung inflammation and neutrophil recruitment in the lungs of C57BL/6 mice. METHODS: C57BL/6 mice were pretreated with the PAR2 antagonist ENMD-1068, compound 48/80 or aprotinin prior to intranasal instillation of MC tryptase or LPS. Blood leukocytes, C-X-C motif chemokine ligand (CXCL) 1 production leukocytes recovered from bronchoalveolar lavage fluid (BALF), and histopathological analysis of the lung were evaluated 4 h later. Furthermore, we performed experiments to determine intracellular calcium signaling in RAW 264.7 cells stimulated with LPS in the presence or absence of a protease inhibitor cocktail or ENMD-1068 and evaluated PAR2 expression in the lungs of LPS-treated mice. RESULTS: Pharmacological blockade of PAR2 or inhibition of proteases reduced neutrophils recovered in BALF and LPS-induced calcium signaling. PAR2 blockade impaired LPS-induced lung inflammation, PAR2 expression in the lung and CXCL1 release in BALF, and increased circulating blood neutrophils. Intranasal instillation of MC tryptase increased the number of neutrophils recovered in BALF, and MC depletion with compound 48/80 impaired LPS-induced neutrophil migration. CONCLUSION: Our study provides, for the first time, evidence of a pivotal role for MCs and MC tryptase in neutrophil migration, lung inflammation and macrophage activation triggered by LPS, by a mechanism dependent on PAR2 activation.

Acute-phase proteins during inflammatory reaction by bacterial infection: Fish-model.

Acute-phase protein (APPs) serum levels have been studied in many human diseases, and their components contribute to host defense during the evolution of infectious diseases by acting as part of the innate immune system. Based on the importance of establishing new experimental models, the present investigation evaluated the modulation of APPs following inflammatory stimulus by the inoculation of Aeromonas hydrophila in tilapias. Fish were sampled 6 and 24 hours post-infection. Tilapias presented increase of positive APPs such as ceruloplasmin, haptoglobin, alpha-2-macroglobulin and complement C3, as well as decrease of negative APPs such as albumin and transferrin. The protein response of tilapias during the course of bacterial infection showed correlation with the kinetics of cellular accumulation in the inflamed focus with significant increase of granulocytes, thrombocytes, lymphocytes and macrophages. However, granulocytes were the predominant cells, associated with increment in the reactive oxygen species (ROS) production. Showing responses similar to those observed in humans, the modulation of APPs and the kinetics of cellular accumulation in the exudate demonstrate the feasibility of this alternative experimental model for advances and studies to understand changes in pathophysiological mechanisms of acute inflammatory reaction due to bacterial infection.

Anti-inflammatory and antinociceptive properties of the hydroalcoholic fractions from the leaves of Annona crassiflora Mart. in mice.

BACKGROUND: Annona crassiflora Mart., popularly known as "Araticum", is a native tree of the Brazilian Cerrado used in folk medicine for treatment of pain and inflammatory diseases. We proposed to analyze analgesic and anti-inflammatory properties of the filtrate (F1) and the precipitate (F2) of the hydroalcoholic fraction from the leaves of Annona crassiflora Mart. in mice. MATERIALS AND METHODS: Swiss mice were submitted to formalin-induced nociception test and tail-flick reflex test, to assess antinociceptive properties, and to the rota-rod test, for motor performance analyses. To evaluate anti-inflammatory properties, F1 and F2 were orally administered 1 h prior to the intrathoracic injection of carrageenan, zymosan, LPS, CXCL8, or vehicle in Balb/c mice and neutrophil infiltration was evaluated 4 h after injection. RESULTS: F1 and F2 reduced the licking time in the second phase of formalin-induced nociception test, but only F2 showed a dose-dependent response. Neither F1 nor F2 reduced the latency time in the tail-flick reflex test. In addition, motor performance alteration was not observed in F1- or F2-treated mice. F2 treatment significantly inhibited the neutrophilia induced by carrageenan, LPS, or CXCL8, but not zymosan. CONCLUSIONS: The experimental data demonstrated that hydroalcoholic fractions of Annona crassiflora Mart. leaves have remarkable anti-inflammatory and antinociceptive activities.

Acute-phase proteins during inflammatory reaction by bacterial infection: fish-model

Acute-phase protein (APPs) serum levels have been studied in many human diseases, and their components contribute to host defense during the evolution of infectious diseases by acting as part of the innate immune system. Based on the importance of establishing new experimental models, the present investigation evaluated the modulation of APPs following inflammatory stimulus by the inoculation of Aeromonas hydrophila in tilapias. Fish were sampled 6 and 24 hours post-infection. Tilapias presented increase of positive APPs such as ceruloplasmin, haptoglobin, alpha-2-macroglobulin and complement C3, as well as decrease of negative APPs such as albumin and transferrin. The protein response of tilapias during the course of bacterial infection showed correlation with the kinetics of cellular accumulation in the inflamed focus with significant increase of granulocytes, thrombocytes, lymphocytes and macrophages. However, granulocytes were the predominant cells, associated with increment in the reactive oxygen species (ROS) production. Showing responses similar to those observed in humans, the modulation of APPs and the kinetics of cellular accumulation in the exudate demonstrate the feasibility of this alternative experimental model for advances and studies to understand changes in pathophysiological mechanisms of acute inflammatory reaction due to bacterial infection.

Chemical composition and anti-inflammatory activity of the leaves of Byrsonima verbascifolia.

An ethnopharmacological survey indicates that the genus Byrsonima has some medicinal species that are commonly found in the Brazilian Cerrado and has been used as an anti-inflammatory and for gastroduodenal disorders. The aim of this study was to evaluate the anti-inflammatory and antioxidant activity along with qualitative chemical characterization of the methanolic extract of the leaves of Byrsonima verbascifolia (BvME) obtained by exhaustive percolation. The data from the chemical analyses by liquid chromatography-mass spectrometry led to tentative identification of 42 compounds belonging to proanthocyanidins, galloyl quinic acid derivatives, flavonoids, and triterpene glycoside derivatives. BvME contain flavonoids and show an antioxidative activity. The methanolic extract administered intraperitoneally at doses of 50, 100, or 300 mg/kg showed a significant reduction in paw edema and modulated the neutrophil influx in a mouse model. Furthermore, the anti-edematogenic activity of the extract provided in smaller doses (12.5 and 25 mg/kg) was also demonstrated in a mouse paw edema model. The extract inhibited NO production by macrophages induced by lipopolysaccharide. We presume that the anti-inflammatory effects of BvME are due to a combination of compounds present in B. verbascifolia, including catechins (procyanidins), flavonoids, and triterpene glycosides and that these anti-inflammatory actions should be mediated, at least partly, through the inhibition of NO production. This study supports and validates the ethnopharmacological uses of B. verbascifolia as an anti-inflammatory.

Nicorandil inhibits neutrophil recruitment in carrageenan-induced experimental pleurisy in mice.

Nicorandil is a drug characterized by the coupling of a nitric oxide (NO) donor to nicotinamide. We have previously demonstrated that nicotinamide exhibits activity in different models of pain and inflammation. Now, we investigated the effects induced by per os (p.o.) administration of nicorandil (25, 50 or 100mg/Kg) on neutrophil recruitment in a carrageenan-induced model of pleurisy in mice. Effects induced by nicorandil (100mg/kg) were compared with those induced by equimolar doses of nicotinamide (58mg/kg) and N-(2-hydroxyethyl)-nicotinamide (NHN; 79mg/kg). We also investigated whether effects on the production of inflammatory mediators play a role in the activity of nicorandil. P.o. nicorandil, 0.5h before and 1h after the i.pl. injection of carrageenan, reduced neutrophil recruitment. However, equimolar doses of nicotinamide or NHN failed to induce such effect. Single treatment (previous or late) with nicorandil (100mg/Kg, p.o.) also reduced neutrophils recruitment, although to a lesser extent when compared to the double treatment. Nicorandil reduced the concentrations of interleukin-1ß, CXCL-1 and prostaglandin E2 in the pleural exudate. Concluding, we demonstrated the activity of nicorandil in a model of pleurisy induced by carrageenan. This activity was characterized by reduction of the neutrophil accumulation and inhibition of production of inflammatory mediators. The effects induced by nicorandil on the leukocytes recruitment and production of inflammatory mediators contribute to a better understanding of its clinical benefits and indicate that these benefits may be due to its vasodilating and anti-inflammatory activities.

Tingenone, a pentacyclic triterpene, induces peripheral antinociception due to NO/cGMP and ATP-sensitive K(+) channels pathway activation in mice.

Substances derived from plants play an important role in the development of new analgesic drugs, among them, triterpenoids. The connection between the participation of L-arginine/NO/cGMP pathway and the activation of ATP-sensitive K(+) channels (KATP) has been established on the peripheral antinociception induced by various drugs. The study assessed the involvement of L-arginine/NO/cGMP/KATP pathway in the antinociceptive effect induced by tingenone, from Maytenus imbricata, against the hyperalgesia evoked by prostaglandin E2 (PGE2) in peripheral pathway. The paw pressure test was used, with hyperalgesia induced by intraplantar injection of PGE2 (2 µg). Tingenone (200 µg/paw) administered into the right hind paw induced a local antinociceptive effect, that was antagonized by l-NOArg, nonselective nitric oxide synthase (NOS) inhibitor and by L-NPA, selective neuronal NOS (nNOS) inhibitor. The L-NIO, selective inhibitor of endothelial (eNOS), and the L-NIL, selective inhibitor of inducible (iNOS), did not alter the peripheral antinociceptive effect of the tingenone. The ODQ, selective soluble guanylyl cyclase inhibitor, prevented the antinociceptive effect of tingenone, and zaprinast, inhibitor of the phosphodiesterase that is cyclic guanosine monophosphate (cGMP) specific, intensified the peripheral antinociceptive effect of the smaller dose of tingenone. Glibenclamide, ATP-sensitive K(+) channels (KATP) blocker, but not tetraethylammonium chloride, voltage-dependent K(+) channel blocker; dequalinium dichloride, blocker of the small conductance Ca(2+)-activated K(+) channel, and paxilline, a potent blocker of high-conductance Ca(2+)-activated K(+) channels, respectively, prevented the peripheral antinociceptive effect of tingenone. The results demonstrate that tingenone induced a peripheral antinociceptive effect by L-arginine/NO/cGMP/KATP pathway activation, with potential for a new analgesic drug.

Tingenone, a pentacyclic triterpene, induces peripheral antinociception due to opioidergic activation.

Plants belonging to the genus Maytenus are routinely used in folk medicine for the treatment of pain diseases. Our previous phytochemical study of the roots of Maytenus imbricata resulted in the isolation and characterization of tingenone, a pentacyclic triterpene. Natural triterpenoids are of growing interest because they have several biological activities, including analgesic properties. The present study assessed the involvement of the opiodergic pathway in the tingenone-induced antinociceptive effect against hyperalgesia induced by prostaglandin E2 (2 µg) in the peripheral pathway. We evaluated the effect of several antagonists to opioid receptors using the mouse paw pressure test. Tingenone administered into the right hind paw induced a local antinociceptive effect that was antagonized by naloxone, a nonselective antagonist to opioid receptors. Clocinnamox, naltrindole, and nor-binaltorphimine are selective antagonists to µ, δ, and κ receptors, respectively, which reverted the peripheral antinociception induced by tingenone. Bestatine acts as an inhibitor of aminopeptidase, an enzyme that degrades endogenous opioid peptides, and was shown to intensify the antinociceptive effect of tingenone. The results suggest that the opioidergic system participates in the peripheral antinociception induced by tingenone.

Bronchoalveolar lavage as a tool for evaluation of cellular alteration during Aelurostrongylus abstrusus infection in cats / Lavado broncoalveolar como ferramenta para avaliação de alterações celulares durante a infecção por Aelurostrongylus abstrusus em gatos

Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from the lungs for evaluation, which helps in the diagnosis of pulmonary diseases. The aim of this study was to perform this procedure for cellular analysis of BAL fluid alterations during experimental infection with Aelurostrongylus abstrusus in cats. Fourteen cats were individually inoculated with 800 third stage larvae of A. abstrusus and five non-infected cats lined as a control group. The BAL procedure was performed through the use of an endotracheal tube on the nineteen cats with a mean age of 18 months, on 0, 30, 60, 90, 120, 180 and 270 days after infection. Absolute cell counts in the infected cats revealed that alveolar macrophages and eosinophils were the predominant cells following infection. This study shows that the technique allows us to retrieve cells and first stage larvae what provides information about the inflammatory process caused by aelurostrongylosis.(AU)

O lavado broncoalveolar (LBA) é um procedimento que permite a recuperação de células e outros elementos pulmonares para avaliação, auxiliando no diagnóstico de doenças pulmonares. O objetivo do presente trabalho foi realizar este procedimento para avaliação das células presentes no fluido broncoalveolar na infecção experimental por Aelurostrongylus abstrusus em gatos. Quatorze animais foram individualmente inoculados com 800 larvas de terceiro estádio de A. abstrusus, enquanto cinco animais não infectados foram mantidos como grupo controle. O LBA foi realizado com uso de um tubo endotraqueal em todos os 19 animais com média de idade de 18 meses, nos dias nos dias 0, 30, 60, 90, 120, 180 e 270 após infecção. A contagem absoluta de células dos animais infectados revelou que macrófagos alveolares e eosinófilos constituíram os tipos celulares predominantes durante todo o período de infecção. Os resultados deste trabalho demonstram que a técnica permite recuperar células e larvas de primeiro estádio de A. abstrusus, fornecendo informações importantes sobre o processo inflamatório causado na aelurostrongilose.(AU)

Bronchoalveolar lavage as a tool for evaluation of cellular alteration during Aelurostrongylus abstrusus infection in cats / Lavado broncoalveolar como ferramenta para avaliação de alterações celulares durante a infecção por Aelurostrongylus abstrusus em gatos

Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from the lungs for evaluation, which helps in the diagnosis of pulmonary diseases. The aim of this study was to perform this procedure for cellular analysis of BAL fluid alterations during experimental infection with Aelurostrongylus abstrusus in cats. Fourteen cats were individually inoculated with 800 third stage larvae of A. abstrusus and five non-infected cats lined as a control group. The BAL procedure was performed through the use of an endotracheal tube on the nineteen cats with a mean age of 18 months, on 0, 30, 60, 90, 120, 180 and 270 days after infection. Absolute cell counts in the infected cats revealed that alveolar macrophages and eosinophils were the predominant cells following infection. This study shows that the technique allows us to retrieve cells and first stage larvae what provides information about the inflammatory process caused by aelurostrongylosis.

O lavado broncoalveolar (LBA) é um procedimento que permite a recuperação de células e outros elementos pulmonares para avaliação, auxiliando no diagnóstico de doenças pulmonares. O objetivo do presente trabalho foi realizar este procedimento para avaliação das células presentes no fluido broncoalveolar na infecção experimental por Aelurostrongylus abstrusus em gatos. Quatorze animais foram individualmente inoculados com 800 larvas de terceiro estádio de A. abstrusus, enquanto cinco animais não infectados foram mantidos como grupo controle. O LBA foi realizado com uso de um tubo endotraqueal em todos os 19 animais com média de idade de 18 meses, nos dias nos dias 0, 30, 60, 90, 120, 180 e 270 após infecção. A contagem absoluta de células dos animais infectados revelou que macrófagos alveolares e eosinófilos constituíram os tipos celulares predominantes durante todo o período de infecção. Os resultados deste trabalho demonstram que a técnica permite recuperar células e larvas de primeiro estádio de A. abstrusus, fornecendo informações importantes sobre o processo inflamatório causado na aelurostrongilose.

Blockade of proteinase-activated receptor 4 inhibits neutrophil recruitment in experimental inflammation in mice.

OBJECTIVE AND DESIGN: The activation of proteinase-activated receptors (PARs) has been implicated in the development of important hallmarks of inflammation, including in vivo leukocyte recruitment; however, its role in the regulation of leukocyte migration in response to inflammatory stimuli has not been elucidated until now. Here, we examined the effects of the PAR4 antagonist YPGKF-NH 2 (tcY-NH2) on neutrophil recruitment in experimentally induced inflammation. METHODS: BALB/c mice were intrapleurally injected with tcY-NH2 (40 ng/kg) prior to intrapleural injection of carrageenan (Cg) or neutrophil chemoattractant CXCL8; the number of infiltrating neutrophils was evaluated after 4 h, and KC production was assessed at different times after Cg injection. Neutrophil adhesion and rolling cells were studied using a brain circulation preparation 4 h after the Cg or CXCL8 challenge in tcY-NH2-treated mice. RESULTS: PAR4 blockade inhibited CXCL8- and Cg-induced neutrophil migration into the pleural cavity of BALB/c mice and reduced neutrophil rolling and adherence. Surprisingly, PAR4 blockade increased the level of KC in response to carrageenan. CONCLUSION: These results demonstrated that PAR4 blockade impairs neutrophil migration in vivo, suggesting that PAR4 plays an important role in the regulation of inflammation, at least in part because of its ability to inhibit the actions of the neutrophil chemoattractant CXCL8.

Proteinase-activated receptor 2 blockade impairs CCL11- or allergen-induced eosinophil recruitment in experimental pleurisy.

Although proteinase-activated receptor (PAR)-2 has been implicated in inflammatory diseases, its role in regulating eosinophil recruitment in response to chemoattractants remains unclear. Here, we investigated the role of PAR-2 and PAR-2-activating Mast Cell (MC) tryptase on chemokine C-C motif ligand (CCL)11- and antigen-induced eosinophil recruitment to the pleural cavity of BALB/c mice. The PAR-2-activating peptide H-Ser-Leu-Ile-Gly-Arg-Leu-NH2 (SLIGRL-NH2) induced eosinophil recruitment whereas PAR-2 blockade inhibited ovalbumin (OVA)- or CCL11-induced eosinophil recruitment. Moreover, OVA and CCL11 induced PAR-2 expression in pleural leukocytes, and the MC tryptase inhibitor APC 366 ([N-(1-hydroxy-2-napthoyl)-l-arginyl-l-prolinamide hydrochloride]) abolished CCL11-induced eosinophil recruitment. These results suggest a pro inflammatory effect of PAR-2 and support a role for MC tryptase mediating eosinophil migration via PAR-2 signaling. Taken together, our results suggest that PAR-2 activation through endogenous MC tryptase activity could be required, at least partially, to mediate CCL11-induced eosinophil migration.