RESUMEN
We investigated the expression of annexin-1 (ANXA1) in thyroid carcinoma cell lines and in thyroid cancers with a different degree of differentiation. The highest level of ANXA1 expression examined by Western blotting was detected in the papillary carcinoma cells (NPA) and in the follicular cells (WRO). On the other hand, the most undifferentiated thyroid carcinoma cells (ARO and FRO) presented the lowest level of ANXA1 expression. In surgical tissue specimens from 32 patients with thyroid cancers, we found high immunoreactivity for ANXA1 in papillary (PTC) and follicular (FTC) thyroid cancers while in undifferentiated thyroid cancers (UTC) the expression of the protein was barely detectable. Control thyroid tissue resulted positive for ANXA1. In summary, 70% of UTC examined weakly expressed ANXA1, whereas 65% of PTC or FTC specimens tested showed high expression of the protein. Thus ANXA1 expression may correlate with the tumorigenesis suggesting that the protein may represent an effective differentiation marker in thyroid cancer.
Asunto(s)
Anexina A1/genética , Neoplasias de la Tiroides/genética , Neoplasias de la Tiroides/patología , Diferenciación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Glándula Tiroides/patología , Células Tumorales CultivadasRESUMEN
In this work, the production of dexametasone and dexametasone acetate microparticles is proposed using supercritical-assisted atomization (SAA). This process is based on the solubilization of supercritical carbon dioxide in a liquid solution containing the drug; then, the ternary mixture is sprayed through a nozzle and submicroparticles are formed as a consequence of the enhanced atomization. Several process parameters such as different organic solvent (methanol and acetone), solute concentration and flow rate ratio between the liquid solution and carbon dioxide are investigated; their influence is evaluated on the morphology and size of precipitated particles. Spherical corticosteroid particles with mean diameters ranging from 0.5 to 1.2 microm are produced at the optimum operating conditions and narrow particle size distributions (PSDs) have also been obtained. No drug degradation was observed after SAA processing and solvent residues of 300 and 500 ppm for acetone and methanol, respectively, were measured. Drug microparticles produced by SAA can be semi-crystalline or amorphous depending on the process condition; a micronized drug surface area ranging from about 4 to 5 m2/g was also observed. The "in vitro" activity of both untreated and SAA processed glucocorticoids was tested on the release of pro-inflammatory cytokines from stimulated cells. The results shown that SAA-glucocorticoids have retained the activity of the parent untreated compounds and, in the case of dexamethasone, SAA processing improves drug performance.
Asunto(s)
Corticoesteroides/administración & dosificación , Corticoesteroides/química , Corticoesteroides/farmacología , Animales , Rastreo Diferencial de Calorimetría , Células Cultivadas , Fenómenos Químicos , Química Física , Cristalización , Citocinas/metabolismo , Dexametasona/administración & dosificación , Dexametasona/química , Dexametasona/farmacología , Composición de Medicamentos , Ratones , Microscopía Electrónica de Rastreo , Nanoestructuras , Tamaño de la Partícula , Solubilidad , Solventes , Propiedades de Superficie , Difracción de Rayos XRESUMEN
The recommendations for the management of osteoarthritis (OA) of the hip were proposed by EULAR in 2005. Among the most important objectives of the expert charged to provide these recommendations were their wide dissemination and implementation. Thus, the information generated can be used by each individual country to produce their own set of management guidelines and algorithms for treatment in primary care. According with that previously executed for the EU-LAR recommendation 2003 for the knee, the Italian Society of Rheumatology (SIR) has organised a Consensus on the EULAR recommendations 2005 for the management of hip OA. To obtain an acceptability as large as possible, the group of experts was composed by many physicians interested in the management of hip OA, including Orthopaedics, Rheumatologists, Physiatrists, and General Practitioners. Main aim of the Consensus was to analyse the acceptability and applicability of the recommendations according to own experience and local situations in the Italy. The results of this Consensus have demonstrated that a large majority of the EULAR recommendations are endorsed by the Italian experts. Furthermore, the final document of the Italian Consensus clearly indicated the need that the specialists involved in the management of hip OA strongly encourage the dissemination of the EULAR 2005 recommendations also in Italy.
Asunto(s)
Osteoartritis de la Cadera/terapia , Guías de Práctica Clínica como Asunto , Atención Primaria de Salud/organización & administración , Unión Europea , Humanos , Italia , Sociedades MédicasRESUMEN
Until recently, the therapeutic effects of furocoumarins and furochromones plus UV-A light were thought to be due to their ability to form photoadducts with DNA in the cell nuclei; now it appears that membrane effector systems may be involved as targets. Here we show that in HeLa cells khellin at 1 and 5 microM final concentration, in combination with UV-A light, inhibits NaF-stimulated adenylyl cyclase activity and Pertussis Toxin (PT)-catalyzed ADP-ribosylation of alpha-subunits of inhibitory guanine nucleotide regulatory proteins (Gi) and increases GTPase activity. In the same experimental conditions, 8-methoxypsoralen (8-MOP), either alone or plus UV-A, does not affect adenylyl cyclase and GTPase activities. Our results suggest that in HeLa cells, through an interaction with a receptor and the mediation of Gi proteins, the adenylyl cyclase system is a target for khellin but not for 8-MOP.
Asunto(s)
Inhibidores de Adenilato Ciclasa , Proteínas de Unión al GTP/metabolismo , Khellin/farmacología , Metoxaleno/farmacología , Adenosina Difosfato Ribosa/metabolismo , Toxina de Adenilato Ciclasa , Adenilil Ciclasas/efectos de la radiación , Oscuridad , GTP Fosfohidrolasas/metabolismo , Células HeLa , Humanos , Membranas/metabolismo , Toxina del Pertussis , Rayos Ultravioleta , Factores de Virulencia de Bordetella/metabolismoRESUMEN
Bidens pilosa L. is a medicinal plant popularly used for treatment of liver diseases. In this study, the dry extract of aerial parts of Bidens pilosa and Silymarin, a phytocomplex obtained from the Silybum marianum fruits and marketed as hepatoprotective, were tested in dogs experimentally acutely intoxicated with carbon tetrachloride. The liver activity was evaluated by hematological and biochemical profiles, and histological and ultrasound analyzes. It was observed that the lowest serum activities of ALT and serum concentrations of total bilirubin occurred in the groups treated with the dry extract of Bidens pilosa, while only decreased serum concentrations of total bilirubin occurred in the group treated with Silymarin. Best liver recovery was also observed for the dry extract of B. pilosa at a 400mg/Kg dose by ultrasonography. This study showed that the dry extract of Bidens pilosa acted more efficiently in the treatment of acute toxic hepatitis induced in dogs than Silymarin.(AU)
Bidens pilosa L. é uma planta medicinal utilizada popularmente para tratamento de doenças hepáticas. Neste trabalho, o extrato seco das partes aéreas da Bidens pilosa e a silimarina, um fitocomplexo obtido dos frutos da Silybum marianum e comercializado como hepatoprotetor, foram testados em cães intoxicados experimentalmente de forma aguda com tetracloreto de carbono. A atividade hepática foi avaliada por meio dos perfis hematológico e bioquímico, análises histológica e ultrassonográfica. Observou-se que, nos grupos tratados com o extrato seco da Bidens pilosa, ocorreram as menores atividades séricas da ALT e de concentrações séricas de bilirrubina total, enquanto no grupo tratado com silimarina, ocorreu apenas diminuição de concentrações séricas de bilirrubina total. Melhor recuperação hepática também foi verificada para o extrato seco de B. pilosa na dose de 400mg/kg por ultrassonografia. Este estudo evidenciou que o extrato seco da Bidens pilosa atuou de forma mais eficiente no tratamento da hepatite aguda tóxica induzida em cães do que a silimarina.(AU)
Asunto(s)
Animales , Perros , Intoxicación por Tetracloruro de Carbono/terapia , Intoxicación por Tetracloruro de Carbono/veterinaria , Bidens/química , Hepatitis Animal/terapia , Plantas Medicinales , Silimarina/uso terapéuticoRESUMEN
The effect of dexamethasone on mRNA and protein synthesis of lipocortins (LCT) 1, 2 and 5 has been investigated in U-937 cells. A constitutive expression of both mRNAs and proteins was detected in undifferentiated U-937 cells. This constitutive level was increased time- and dose-dependently by incubation with phorbol myristate acetate (PMA). In U-937 cells differentiated by 24 h incubation with 6 ng/ml PMA, dexamethasone (DEX) (1 microM for 16 h) caused an increased synthesis of the mRNA level of LCT-1 and 2, but not of LCT-5, over the level induced by PMA. DEX had no effect in undifferentiated cells. Moreover, DEX stimulated the extracellular release of LCT-1 and 5, but not of LCT-2, and inhibited the release of PGE2 and TXB2 only in the differentiated U-937 cells. These results suggest that the responsiveness of these cells to glucocorticoids is dependent on the phase of cell differentiation. The selective release of lipocortins by differentiated U-937 cells may explain, at least in part, the inhibition by DEX of the prostanoid release.
Asunto(s)
Proteínas de Unión al Calcio/genética , Diferenciación Celular/genética , Dexametasona/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Macrófagos/metabolismo , Monocitos/metabolismo , ARN Mensajero/metabolismo , Anexinas , Ácidos Araquidónicos/metabolismo , Secuencia de Bases , Proteínas de Unión al Calcio/biosíntesis , Línea Celular , Humanos , Macrófagos/efectos de los fármacos , Datos de Secuencia Molecular , Monocitos/efectos de los fármacos , ARN Mensajero/químicaRESUMEN
The tuftsin retro-inverso analogue H-Thr psi[NHCO](R,S)Lys-Pro-Arg-OH was synthesized through a novel procedure for the high-yield incorporation of isolated retro-inverso bonds into peptide chains and the use of the new Meldrum's acid derivative (CH3)2C(OCO)2CH(CH2)4NHCOCF3 followed by its efficient coupling in solution to trimethylsilylated H-D-Thr(t-Bu)NH2. Closely related peptide impurities were eliminated both from the crude final peptide and the fully protected tetrapeptide amide precursor via ion-exchange and reversed-phase displacement chromatography, respectively. The tuftsin retro-inverso analogue proved to be completely resistant to enzymatic degradation in vitro, either against isolated aminopeptidases or human plasma proteolytic enzymes. When administered either orally or intravenously, it was significantly more active than normal tuftsin in increasing the number of specific antibody secreting cells in spleen of mice immunized with sheep erythrocytes. Furthermore, the analogue exerted an enhanced stimulatory effect on the cytotoxic activity of splenocytes against YAC-1 tumor cells. Finally, retro-inverso-tuftsin was about 10-fold more potent than the native peptide in reducing rat adjuvant arthritis. The resistance of the retro-inverso analogue to peptidases might explain the increased in vivo activities and allows its further immunopharmacological characterization.
Asunto(s)
Adyuvantes Inmunológicos/síntesis química , Tuftsina/análogos & derivados , Adyuvantes Inmunológicos/metabolismo , Adyuvantes Inmunológicos/farmacología , Secuencia de Aminoácidos , Animales , Formación de Anticuerpos/efectos de los fármacos , Artritis Experimental/terapia , Estabilidad de Medicamentos , Eritrocitos/inmunología , Femenino , Humanos , Células Asesinas Naturales/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Datos de Secuencia Molecular , Péptido Hidrolasas/metabolismo , Ratas , Ratas Endogámicas Lew , Ovinos , Tuftsina/síntesis química , Tuftsina/metabolismo , Tuftsina/farmacologíaRESUMEN
Interleukin-1 beta (IL-1 beta) has been shown to specifically increase the release of prostaglandin (PG) E2 from rat hypothalamic explants in short-term experiments. In this study we attempted to characterize the receptor subtype(s) involved in this response. Rat hypothalamic explants were incubated with mouse monoclonal antibodies (mAbs) raised against human IL-1 type I or type II receptors, IL-1 receptor antagonist (IL-1ra) and alpha-melanocyte-stimulating hormone (alpha-MSH) (which appears to antagonize certain IL-1 induced inflammatory effects in vivo), alone and in the presence of IL-1 beta. PGE2 released into the incubation medium was measured by radioimmunoassay. The anti-type I mAb reduced both basal and IL-1 beta-stimulated PGE2 release at 10 micrograms/ml, but not at lower concentrations. The anti-type II mAb also produced a significant decrease in stimulated release but had no effect on basal release. IL-1ra mimicked the effects of the anti-type I mAb, while alpha-MSH failed to alter either basal or stimulated PGE2 release. These findings suggest that IL-1 beta controls production and release of PGE2 by the rat hypothalamus via both type I and type II receptors, although the latter appear to be involved only in the response to high levels of IL-1.
Asunto(s)
Dinoprostona/metabolismo , Hipotálamo/metabolismo , Interleucina-1/fisiología , Receptores de Interleucina-1/fisiología , Animales , Anticuerpos Monoclonales/inmunología , Humanos , Técnicas Inmunológicas , Proteína Antagonista del Receptor de Interleucina 1 , Masculino , Ratones , Ratas , Ratas Wistar , Receptores de Interleucina-1/inmunología , Sialoglicoproteínas/farmacología , alfa-MSH/farmacologíaRESUMEN
1. Human embryonic skin fibroblasts (HSF) incubated overnight with either human recombinant interleukin-1 alpha (rIL-1 alpha) or interleukin-1 beta (rIL-1 beta) released large amounts of prostaglandin E2 (PGE2). 2. rIL-1 beta, bradykinin (Bk) and arachidonic acid (AA) significantly stimulated PGE2 release from HSF incubated overnight in the presence of either interleukin. 3. Hydrocortisone inhibited the PGE2 release induced by rIL-1 beta and Bk, but not by AA. 4. The steroid inhibitory effect was reversed by actinomycin D as well as by an anti-lipocortin monoclonal antibody. 5. The results suggest that in HSF, rIL-1 beta is able to stimulate both cyclo-oxygenase and phospholipase A2 (PLA2) activity. 6. The stimulation of PLA2 activity by rIL-1 beta is inhibited by hydrocortisone, probably via induction of lipocortin-like proteins.
Asunto(s)
Fosfolipasas A/metabolismo , Fosfolipasas/metabolismo , Anticuerpos Monoclonales , Células Cultivadas , Dactinomicina/farmacología , Dinoprostona/biosíntesis , Dinoprostona/metabolismo , Fibroblastos/enzimología , Humanos , Hidrocortisona/farmacología , Interleucina-1/farmacología , Fosfolipasas A2 , Proteínas Recombinantes/farmacologíaRESUMEN
Lipocortin (annexin) 1 is a putative mediator of the inflammatory effects of glucocorticoids. By flow cytometric analysis (FACS) we have studied the effect of dexamethasone on the cellular localization of lipocortin 1. U-937 cells were incubated with or without 10 nM phorbol 12-myristate 13-acetate (PMA) to induce cell differentiation. Then 1 microM dexamethasone was added and incubation carried out for increasing times (1-24 h). Dexamethasone caused a time-dependent biphasic translocation of lipocortin 1 from the intracellular compartment to the cell membrane with maximal membrane expression at 4 and 24 h. In differentiated U-937 cells the steroid-induced membrane accumulation of lipocortin 1 was significantly higher than that of undifferentiated cells. The accumulation of the protein in the cell membrane may precede its release which is stimulated by dexamethasone in differentiated U-937 cells. Since extracellular lipocortin 1 has anti-inflammatory properties the modulation of the translocation/secretion process of the protein by glucocorticoids may be part of their mechanism of action.
Asunto(s)
Anexina A1/metabolismo , Dexametasona/farmacología , Anexina A1/biosíntesis , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Humanos , Acetato de Tetradecanoilforbol/farmacocinéticaRESUMEN
The release of platelet-activating factor (Paf-acether) and of its inactive precursor/metabolite lyso-platelet activating factor (lyso-Paf) from control and sensitized guinea-pig isolated lungs challenged with antigen was investigated. Control guinea-pig lungs perfused either through the pulmonary circulation or through the airways and challenged with antigen did not release Paf-acether. Sensitized guinea-pig isolated lungs perfused through the pulmonary circulation and challenged with antigen released lyso-Paf but not Paf-acether. Sensitized guinea-pig isolated lungs perfused through the airways and challenged with antigen released three times more lyso-Paf and also Paf-acether. These results support a possible role for Paf-acether in respiratory anaphylaxis in the guinea-pig.
Asunto(s)
Anafilaxia/metabolismo , Pulmón/metabolismo , Factor de Activación Plaquetaria/metabolismo , Animales , Cobayas , Técnicas In Vitro , Masculino , Perfusión , Factor de Activación Plaquetaria/análogos & derivados , Circulación Pulmonar , Factores de TiempoRESUMEN
1 Peritoneal macrophages (M phi) collected from adrenalectomized (ADX) rats released more interleukin-1 (IL-1) activity and prostaglandin E2 (PGE2) than macrophages from sham-operated (SHO) rats. 2 The increase in IL-1 activity in the supernatants was confirmed by the increase of the cell-associated 33 kD IL-1 alpha precursor in ADX macrophages stimulated by lipopolysaccharide (LPS). 3 After the injection of Complete Freund's Adjuvant (CFA) to induce adjuvant arthritis, 60% of the ADX rats died, while no deaths occurred in the SHO group. 4 The in vivo administration of dexamethasone inhibited both IL-1 and PGE2 release by macrophages as well as protecting ADX animals from CFA-induced death. Indomethacin and BW 755C partially protected the animals from this lethal effect. 5 These results suggest that adrenalectomy induces an increased release of IL-1 both in vitro and in vivo, and are consistent with a feedback mechanism between IL-1 and glucocorticoid hormones.
Asunto(s)
Adrenalectomía , Interleucina-1/metabolismo , 4,5-dihidro-1-(3-(trifluorometil)fenil)-1H-pirazol-3-amina/farmacología , Animales , Células Cultivadas , Dexametasona/farmacología , Dinoprostona/metabolismo , Adyuvante de Freund/farmacología , Humanos , Técnicas In Vitro , Indometacina/farmacología , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Pruebas de Precipitina , Ratas , Ratas EndogámicasRESUMEN
Carrageenin pleurisy was induced in adrenalectomised (ADX) and sham-operated (SHO) rats. The magnitude and duration of inflammation, as estimated by fluid exudation and cell migration, was greatly increased (approximately doubled) in ADX rats compared with that in their SHO controls. The content of eicosanoids (6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha), thromboxane B2 (TXB2), and leukotriene B4 (LTB4] in inflammatory exudates from ADX rats was significantly (2-4 fold) greater than that of their SHO controls. Resident macrophages obtained from ADX rats produced more eicosanoids per cell per unit time when stimulated in vitro with zymosan, than did cells from the SHO controls. Administration of glucocorticoids blocked the inflammatory response and reduced the release of eicosanoids both in vitro and in vivo in both groups of rats. These data are consistent with the notion that physiological amounts of glucocorticoids exert a tonic inhibitory action on phospholipase activity in normal animals and that the increased secretion of these hormones during the inflammatory response serves to check and control the development of inflammation.
Asunto(s)
Adrenalectomía , Inflamación/metabolismo , 6-Cetoprostaglandina F1 alfa/análisis , 6-Cetoprostaglandina F1 alfa/biosíntesis , Enfermedad Aguda , Animales , Anexinas , Carragenina , Glucocorticoides/farmacología , Glicoproteínas/fisiología , Técnicas In Vitro , Leucotrieno B4/análisis , Leucotrieno B4/biosíntesis , Fosfolipasas A/fisiología , Pleuresia/etiología , Ratas , Tromboxano B2/análisis , Tromboxano B2/biosíntesisRESUMEN
1. This study investigates the role of extracellular brain calcium in the hyperthermia induced by interleukin-1 beta (IL-1 beta). 2. Intracerebroventricular (i.c.v.) injection of IL-1 beta (12.5 ng kg-1) in rabbits caused a prompt and sustained rise in cerebrospinal fluid (CSF) Ca2+ concentration ([Ca2+]) followed by enhanced prostaglandin E2 (PGE2) release and hyperthermia. 3. A linear and significant correlation was observed between the increase in [Ca2+] induced by IL-1 beta and the rise in body temperature. 4. Ventriculo-cisternal perfusion with artificial CSF containing the calcium chelator EGTA (1.3 mM) blocked the IL-1-induced PGE2 release and countered the febrile response. 5. I.c.v. administration of dexamethasone (Dex) (2.4 and 24 micrograms kg-1) 100 min prior to IL-1 beta, dose-dependently antagonized the cytokine-induced Ca2+ increase, the PGE2 release and the febrile response. 6. These results suggest that changes in extracellular brain calcium are involved in the regulation of body temperature. In this light, the antipyretic action of Dex may be related to its effect on Ca2+ uptake.
Asunto(s)
Regulación de la Temperatura Corporal/efectos de los fármacos , Química Encefálica/fisiología , Calcio/fisiología , Dexametasona/farmacología , Espacio Extracelular/fisiología , Interleucina-1/farmacología , Animales , Química Encefálica/efectos de los fármacos , Calcio/líquido cefalorraquídeo , Dexametasona/administración & dosificación , Dinoprostona/biosíntesis , Ácido Egtácico/farmacología , Espacio Extracelular/metabolismo , Inyecciones Intraventriculares , Interleucina-1/administración & dosificación , Interleucina-1/antagonistas & inhibidores , Masculino , ConejosRESUMEN
1. A novel anti-inflammatory peptide (residues 204-212) of human recombinant lipocortin 5 (hrLC5) found on the high similarity region with uteroglobin is described. 2. Peptide 204-212 dose-dependently inhibited the contractions of rat isolated stomach strips elicited by porcine pancreatic phospholipase A2 (PLA2). Contractions caused by arachidonic acid (AA), prostaglandin E2 (PGE2) and 5-hydroxytryptamine were not affected. No direct enzyme inhibition was observed in a radiochemical assay. 3. PGE2 release by both human fibroblasts and rat macrophages was reduced by peptide 204-212 in a dose-dependent manner. 4. The development of carrageenin-induced oedema in rats was significantly inhibited by the local administration of peptide 204-212. 5. The pattern and potency of the biological effects of peptide 204-212 are similar to those of antiflammin 2, a lipocortin 1-derived peptide. 6. It is suggested that peptide 204-212 may represent the active site responsible for the anti-inflammatory properties of lipocortin 5.
Asunto(s)
Antiinflamatorios no Esteroideos , Proteínas de Unión al Calcio/farmacología , Péptidos/farmacología , Proteínas Gestacionales/farmacología , Secuencia de Aminoácidos , Animales , Anexina A5 , Proteínas de Unión al Calcio/análisis , Carragenina , Dinoprostona/metabolismo , Edema/inducido químicamente , Edema/fisiopatología , Humanos , Masculino , Datos de Secuencia Molecular , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Fosfolipasas A/antagonistas & inhibidores , Fosfolipasas A2 , Proteínas Gestacionales/análisis , Conejos , Ratas , Ratas Endogámicas , Proteínas Recombinantes/análisis , Proteínas Recombinantes/farmacología , Alineación de Secuencia , Uteroglobina/análisisRESUMEN
1. Activated microglial cells are believed to play an active role in most brain pathologies, during which they can contribute to host defence and repair but also to the establishment of tissue damage. These actions are largely mediated by microglial secretory products, among which are prostaglandins (PGs) and nitric oxide (NO). 2. The anti-inflammatory protein, lipocortin 1 (LC1) was reported to have neuroprotective action and to be induced by glucocorticoids in several brain structures, with a preferential expression in microglia. In this paper we tested whether the neuroprotective effect of LC1 could be explained by an inhibitory effect on microglial activation. 3. We have previously shown that bacterial endotoxin (LPS) strongly stimulates PGE2 and NO production in rat primary microglial cultures, by inducing the expression of the key enzymes cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), respectively. 4. Dexamethasone (DEX, 1-100 nM) and LC1-derived N-terminus peptide (peptide Ac2-26, 1-100 microg ml(-1)) dose-dependently inhibited the production of both PGE2 and NO from LPS-stimulated microglia. The inhibitory effects of DEX on NO and of the peptide on NO and PGE2 synthesis were partially abrogated by a specific antiserum, raised against the N-terminus of human LC1. The peptide Ac2-26 did not affect arachidonic acid release from control and LPS-stimulated microglial cultures. 5. Western blot experiments showed that the LPS-induced expression of COX-2 and iNOS was effectively down-regulated by DEX (100 nM) and peptide Ac2-26 (100 microg ml(-1)). 6. In conclusion, our findings support the hypothesis that LC1 may foster neuroprotection by limiting microglial activation, through autocrine and paracrine mechanisms.
Asunto(s)
Anexina A1/farmacología , Isoenzimas/efectos de los fármacos , Microglía/efectos de los fármacos , Óxido Nítrico Sintasa/efectos de los fármacos , Prostaglandina-Endoperóxido Sintasas/efectos de los fármacos , Animales , Animales Recién Nacidos , Anexina A1/biosíntesis , Antiinflamatorios no Esteroideos/farmacología , Ácido Araquidónico/metabolismo , Ciclooxigenasa 2 , Dexametasona/farmacología , Dinoprostona/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Glucocorticoides/farmacología , Humanos , Isoenzimas/metabolismo , Proteínas de la Membrana , Microglía/citología , Microglía/enzimología , Óxido Nítrico Sintasa/biosíntesis , Óxido Nítrico Sintasa de Tipo II , Fragmentos de Péptidos/farmacología , Péptidos , Prostaglandina-Endoperóxido Sintasas/metabolismo , RatasRESUMEN
1 Dexamethasone and hydrocortisone induced the release of anti-phospholipase proteins into the peritoneal cavities of rats. 2 Adrenocorticotrophic hormone (ACTH) also releases these proteins in normal but not in adrenalectomized rats. 3 Peritoneal lavage proteins were separated by ion-exchange and size exclusion chromatography. The anti-phospholipase activity occurred in four separate fractions with the major component having an apparent mol. wt. of 40 k. 4 Column fractions containing these anti-phospholipase proteins had anti-inflammatory effects in the rat carrageenin pleurisy model whereas other fractions were inactive. 5 The proteins appear to be identical to macrocortin and lipomodulin, the 'second messengers' of glucocorticoid hormone action on the arachidonate system.
Asunto(s)
Glucocorticoides/farmacología , Inflamación/metabolismo , Fosfolipasas/antagonistas & inhibidores , Proteínas/metabolismo , Hormona Adrenocorticotrópica/farmacología , Animales , Líquidos Corporales/metabolismo , Masculino , Cavidad Peritoneal/metabolismo , Fosfolipasas A/antagonistas & inhibidores , Proteínas/fisiología , Ratas , Ratas Endogámicas , Extractos de Tejidos/farmacologíaRESUMEN
Anti-inflammatory steroids induce the release in vivo of antiphospholipase proteins (APP) into the peritoneal cavities of rats. APP were partially purified by ion- exchange chromatography. The main anti-phospholipase activity was recovered in two zones of the elution gradient named APP I and APP II; their molecular weight (mol. wt) was determined with molecular sieve chromatography. Two phospholipase A2 (PLA2) activities were identified from rat peritoneal leucocytes, one with a pH optimum at 4.5 (a lysosomal enzyme) and one with pH optimum at 8.5 (a membrane-bound enzyme); the selective secretion of the former was observed when leucocytes were stimulated by phagocytosis. The effect of APP on both enzyme activities was studied on enzyme preparations from resting leucocytes. APP were also added to leucocytes incubated with or without phagocytozable material. After incubation, PLA2 activities were determined both inside the cells and in the culture medium. APP I revealed a mol. wt of 200 k with a small fragment of 15 k and inhibited membrane-bound PLA2; APP II revealed a mol. wt of 40 k and inhibited lysosomal PLA2.
Asunto(s)
Glucocorticoides/farmacología , Lisosomas/enzimología , Fosfolipasas A/antagonistas & inhibidores , Fosfolipasas/antagonistas & inhibidores , Proteínas/farmacología , Animales , Antiinflamatorios/farmacología , Membrana Celular/enzimología , Concentración de Iones de Hidrógeno , Leucocitos/enzimología , Masculino , Fosfolipasas A2 , Proteínas/aislamiento & purificación , Ratas , Ratas EndogámicasRESUMEN
It has been suggested that the induction of lipocortin-1, a phospholipase A2-inhibitory protein, may mediate the anti-inflammatory action of glucocorticoids. We assessed the production of prostaglandin E2, thromboxane B2, and leukotriene B4 and the expression of lipocortin-1 in different populations of blood leukocytes and in alveolar macrophages (obtained by bronchoalveolar lavage) from patients with inflammatory lung diseases (bronchial asthma, n = 21; interstitial lung disease, n = 6) undergoing glucocorticoid treatment at clinically effective doses. No inhibition of eicosanoid production was observed in either whole blood or single populations of blood leukocytes (granulocytes and monocytes) stimulated with ionophore A-23187, N-formyl-L-methionyl-L-leucyl-L-phenylalanine, or zymosan. Conversely, eicosanoid production from alveolar macrophages (assessed in 9 cases) was significantly inhibited by glucocorticoids. After ionophore stimulation, eicosanoid production was as follows (in ng/ml): prostaglandin E2, 0.19 +/- 0.06 and 0.06 +/- 0.01; thromboxane B2, 2.9 +/- 0.9 and 0.5 +/- 0.1; leukotriene B4, 6.6 +/- 1.1 and 3.6 +/- 1.0, before and after treatment, respectively (P < 0.05 for all differences). Lipocortin-1 expression, determined by Western blot and enzyme immunoassay, was significantly (P < 0.05) stimulated in alveolar macrophages, but not in blood leukocytes, by glucocorticoid treatment. These results indicate that alveolar macrophages, at variance from blood leukocytes, are the most likely cell target for glucocorticoid-induced eicosanoid inhibition and lipocortin expression. We suggest that cell responsiveness to glucocorticoids is acquired during differentiation from monocyte to tissue macrophage.
Asunto(s)
Anexina A1/biosíntesis , Eicosanoides/biosíntesis , Glucocorticoides/farmacología , Macrófagos Alveolares/metabolismo , Adolescente , Adulto , Anciano , Secuencia de Aminoácidos , Asma/sangre , Asma/metabolismo , Western Blotting , Líquido del Lavado Bronquioalveolar , Quimiotaxis de Leucocito/efectos de los fármacos , Femenino , Humanos , Recuento de Leucocitos , Leucocitos/efectos de los fármacos , Leucocitos/metabolismo , Enfermedades Pulmonares/sangre , Enfermedades Pulmonares/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Superóxidos/metabolismoRESUMEN
Adherent guinea-pig alveolar macrophages stimulated in vitro with FMLP (1 microM) for 5-60 min released PAF-acether, TXB2 and LTB4, with maximal levels being achieved after a 5 min incubation. The levels of eicosanoids were maintained during the 60 min incubation period, whereas the levels of PAF-acether decreased and were no longer detectable after 60 min incubation. Indomethacin (1 microM) completely suppressed the release of TXB2 stimulated by FMLP (1 microM for 5 min) whilst potentiating the release of LTB4. The selective 5-lipoxygenase inhibitor, BW A137C (1 microM), abolished the stimulated release of LTB4 without affecting the release of TXB2. BW755C (1-20 microM) caused a dose-related inhibition of TXB2 release but did not affect LTB4 release, while none of the drugs studied affected the release of PAF-acether. These results indicate that the FMLP-induced release of PAF-acether from guinea-pig alveolar macrophages is not susceptible to modulation by selective inhibition of lipoxygenase or cyclo-oxygenase and is therefore not secondary to the synthesis of LTB4 or TXB2.