Uso de neumocitos de tipo II en el tratamiento de enfermedades pulmonares asociadas con fibrosis pulmonar

Se describe el empleo de neumocitos tipo II como agentes inhibidores de la proliferación de fibroblastos, por lo que pueden ser utilizados en la elaboración de un medicamento para el tratamientode enfermedades pulmonares que cursan con fibrosis pulmonar.Peer reviewedConsejo Superior de Investigaciones Científicas (España)T3 Traducción de patente europe

In vivo antioxidant treatment protects against bleomycin-induced lung damage in rats

This study examines the activity of the antioxidant N-acetylcysteine on bleomycin-induced pulmonary fibrosis in rats with emphasis on the early inflammatory phase. Rats receiving N-acetylcysteine (300 mg kg−1 day−1, intraperitoneal) had less augmented lung wet weight, and lower levels of proteins, lactate dehydrogenase, neutrophil and macrophage counts in bronchoalveolar lavage fluid and lung myeloperoxidase activity with a betterment of histological score at 3 days postbleomycin. A diminished lung GSH/GSSG ratio and augmented lipid hydroperoxides were observed 3 days postbleomycin. These changes were attenuated by N-acetylcysteine. Alveolar macrophages from bleomycin-exposed rats released augmented amounts of superoxide anion and nitric oxide. N-Acetylcysteine did not modify superoxide anion generation but reduced the increased production of nitric oxide. N-Acetylcysteine suppressed the bleomycin-induced increased activation of lung NF-κB (shift assay and immunohistochemistry), and decreased the augmented levels of the early inflammatory cytokines, tumour necrosis factor-α, interleukin-β, interleukin-6 and macrophage inflammatory protein-2 observed in bronchoalveolar lavage fluid at 1 and 3 days postbleomycin exposure. At 15 days postbleomycin, N-acetylcysteine decreased collagen deposition in bleomycin-exposed rats (hydroxyproline content: 6351±669 and 4626±288 μg per lung in drug vehicle- and N-acetylcysteine-treated rats, respectively; P<0.05). Semiquantitative histological assessment at this stage showed less collagen deposition in N-acetylcysteine-treated rats compared to those receiving bleomycin alone. These results indicate that N-acetylcysteine reduces the primary inflammatory events, thus preventing cellular damage and the subsequent development of pulmonary fibrosis in the bleomycin rat model.This work was supported by Grant 1FD97-1143 from the European Union (Regional Development Funds, FEDER), CICYT (Spanish Government), Regional Government (Generalitat Valenciana) and Grant FIS98/1367 (Spanish Ministry of Health).Peer reviewe

Morphological Study of Gastric Lesions Developing in the Rat Under Several Damaging Conditions: Modifications Induced by Pretreatment with Zinc Acexamate

Lesions developing in the gastric mucosa of the rat after exposure to different gastric damaging agents (100 mg/kg aspirin, and 70% or 100% ethanol) were assessed by scanning electron microscopy. The severity of the lesions was quantified according to morphological criteria. Modifications in the severity of these lesions induced by pretreatment with zinc acexamate were also analyzed. The scanning electron microscope revealed that with the exception of absolute ethanol, which caused distinctive morphological features, lesions found under the different experimental agents shared a common pattern of progression. Ultrastructural lesions on surface epithelial cells preceded further alterations of parietal cells. After the integrity of the epithelial cells was lost, detachment of the parietal cells occurred, probably, through peptic digestion of the connections between cells and their extracellular matrices. Pretreatment of animals with zinc acexamate increased the presence of mucus on the gastric surface and significantly prevented the progression of lesions towards the severest stages. Ultrastructural damage of surface epithelial cells was not influenced by this treatment, but detachment of damaged cells was clearly diminished. These data confirm the protective effect of zinc acexamate against gastric aggressions. Moreover, our studies confirm the notion that mucus secretion and maintenance of continuity on the gastric lumen by surface epithelial cells is of critical importance in preventing the gastric damage induced in these experimental models

Mobilization of xanthine oxidase from the gastrointestinal tract in acute pancreatitis

BACKGROUND: Xanthine oxidoreductase has been proposed to play a role in the development of local and systemic effects of acute pancreatitis. Under physiologic conditions, the enzyme exists mainly as xanthine dehydrogenase (XDH) but can be converted by proteolytic cleavage to its superoxide-generating form xanthine oxidase (XOD). In addition to its intracellular location XDH/XOD is also associated to the polysaccharide chains of proteoglycans on the external endothelial cell membrane. In the early stages of acute pancreatitis, this enzyme seems to be arising from its mobilization from the gastrointestinal endothelial cell surface. Taking into account the ability of α-amylase to hydrolyze the internal α-1,4 linkages of polysaccharides, we wanted to elucidate the involvement of α-amylase in XDH/XOD mobilization from the gastrointestinal endothelial cell surface and the relevance of the ascitic fluid (AF) as the source of α-amylase in experimental acute pancreatitis. METHODS: Acute pancreatitis was induced in male Wistar rats by intraductal administration of 5% sodium taurocholate. In another experimental group 3000 U/Kg α-amylase was i.v. administered. The concentrations of XDH, XOD and α-amylase in plasma and AF and myeloperoxidase (MPO) in lung have been evaluated. In additional experiments, the effect of peritoneal lavage and the absorption of α-amylase present in the AF by an isolated intestine have been determined. RESULTS: Similar increase in XDH+XOD activity in plasma was observed after induction of acute pancreatitis and after i.v. administration of α-amylase. Nevertheless, the conversion from XDH to XOD was only observed in the pancreatitis group. Lung inflammation measured as MPO activity was observed only in the pancreatitis group. In addition peritoneal lavage prevented the increase in α-amylase and XDH+XOD in plasma after induction of pancreatitis. Finally, it was observed that α-amylase is absorbed from the AF by the intestine. CONCLUSIONS: During the early stages of acute pancreatitis, α-amylase absorbed from AF through the gastrointestinal tract could interfere with the binding of XDH/XOD attached to glycoproteins of the endothelial cells. Proteolytic enzymes convert XDH into its oxidase form promoting an increase in circulating XOD that has been reported to be one of the mechanisms involved in the triggering of the systemic inflammatory process

Macrophage activation in exacerbated COPD with and without community-acquired pneumonia

In large series of nonresponding community-acquired pneumonia (CAP) patients, chronic obstructive pulmonary disease (COPD) was observed to be a protective factor for nonresponse to initial antibiotics. This intriguing fact may be linked to changes in the phenotype of inflammatory cells and, in particular, to the induction of classical-M1 or alternative-M2 activation of macrophages, which result in different inflammatory profiles. We evaluated the effect of sputum obtained from patients with acute exacerbation of COPD (AECOPD), CAP and COPD+CAP on the phenotypic changes in macrophages. Human THP1 cells differentiated to macrophages were incubated with sputum from patients with AECOPD, CAP or COPD+CAP, and expression of tumour necrosis factor-α, interleukin-6, mannose receptor and arginase was measured to evaluate the phenotype acquired by macrophages. We found that sputum from CAP patients induced the M1 phenotype and that from AECOPD patients induced an M2-like phenotype. Sputum from CAP+COPD patients did not present a clear M1 or M2 phenotype. These results indicate that the microenvironment in the lung modulates the activation of macrophages, resulting in different phenotypes in AECOPD, CAP and COPD+CAP patients. This different type of activation induces different inflammatory responses and may be involved in the different outcome observed when COPD and CAP present simultaneously. Copyright© ERS 2010.The present work received funding from the projects SAF2006-08449, FIS041140, La Marató de TV3- 040530 and Ciber de Enfermedades Respiratorias (Ciberes), an initiative of the Carlos III Health Institute, Barcelona, Spain. R. Piñer and A. Torres were supported by: 2009 SGR911, Ciber de Enfermedades Respiratorias (Ciberes CB06/06/0028), el Ciberes es una iniciativa del ISCIII, Barcelona, Spain.Peer Reviewe

Intratracheal transplantation of alveolar type II cells reverses bleomycin-induced lung fibrosis

[Rationale]: Transplantation of stem cells has been proposed as a strategy for repair of lung fibrosis. Nevertheless, many studies have yielded controversial results that currently limit the potential use of these cells as an efficient treatment. Alveolar type II cells are the progenitor cells of the pulmonary epithelium and usually proliferate after epithelial cell injury. During lung fibrosis, however, the altered regeneration process leads to uncontrolled fibroblast proliferation. [Objectives]: To investigate whether intratracheal transplantation of isolated alveolar type II cells can halt and reverse the fibrotic process in an experimental model of bleomycin-induced lung fibrosis in rats. [Methods]: Lung fibrosis was induced in syngeneic female Lewis rats by a single intratracheal instillation of bleomycin (2.5 U/kg). Animals were transplanted with alveolar type II cells from male animals at a dose of 2.5 × 106 cells per animal 3, 7, and 15 days after endotracheal bleomycin instillation. Animals were killed 21 days after the induction of lung fibrosis. [Measurements and Main Results]: Lung fibrosis was assessed by histologic study anddetermination of hydroxyproline content. Engraftment of transplanted cells was measured by real-time polymerase chain reaction for the Y chromosome and by fluorescence in situ hybridization for the Y chromosome. Transplantation of alveolar type II cells into damaged lung 3, 7, or 15 days after bleomycin instillation led to reduced collagen deposition, and reduction in the severity of pulmonary fibrosis. [Conclusions]: This study demonstrates the potential role of alveolar type II cell transplantation in designing future therapies for lung fibrosis.Supported by grant FIS PI060679 from the Spanish Ministry of Health and by grant N-2005-79 from the Sociedad Española de Neumología y Cirugía Torácica (SEPAR).Peer Reviewe

Perfil cinético y metabólico del antohipoxico cerebral etil-hidro-cantinona

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Biological consequences of oxygen desaturation and respiratory effort in an acute animal model of obstructive sleep apnea (OSA)

El pdf del artículo es el manuscrito de autor.[Background]: An animal model mimicking all the factors involved in obstructive sleep apnea (OSA) is useful for investigating mechanisms because the associated comorbidity usually present in such patients is an important limitation.[Aim]: To test the hypothesis that hypoxia/normoxia and respiratory effort have different effects on the induction of inflammatory response and endothelial dysfunction in an acute rat model of OSA.[Methods]: Four groups of anesthetized rats were studied (n = 8): (1) sham; (2) apnea: obstructions (15 s each, 60/h, for 3 h); (3) apnea + O2: obstructions and breathing oxygen-enriched air to avoid hypoxia and (4) intermittent hypoxia/normoxia. Inflammatory and endothelial mediators were measured as outcomes along with NF-κB in the lung and diaphragm.[Results]: TNF-α and IL-1β significantly increased in all groups compared with sham. NF-κB in the lung was increased in apnea and hypoxia/normoxia groups, but not in apnea + O2 group. In diaphragm tissue, NF-κB was only significant in apnea compared to sham. Significant differences were found in the ratio thromboxane-B2/6-keto-Prostaglandin-F1α between apnea and hypoxia/normoxia compared to sham but not in apnea + O2.[Conclusions]: Oxygen desaturations and respiratory efforts play a role in the induction of systemic inflammation but only hypoxia/normoxia induces endothelial dysfunction. These data suggest a potential role for oxygen therapy in patients with OSA.This work was supported in part by Ministerio de Ciencia y Tecnología (SAF2008-02991 and PI080277), SEPAR, FUCAP.Peer reviewe

Oxidised lipids present in ascitic fluid interfere with the regulation of the macrophages during acute pancreatitis, promoting an exacerbation of the inflammatory response

[Background]: Pancreatitis-associated ascitic fluid (PAAF) plays a critical role in the pathogenesis of acute pancreatitis. Taking into consideration that damaged pancreas exudates high concentrations of lipolytic enzymes in the peritoneal cavity, large amounts of lipid metabolism derived products could occur in PAAF. In this study, we have examined the involvement of the lipid fraction of PAAF generated in the early stages of experimental acute pancreatitis.[Methods]: Pancreatitis was induced in rats by intraductal administration of 5% sodium taurocholate. After three hours, PAAF was collected and its lipid fraction was obtained. Lipid composition and levels of lipid peroxidation were measured. Toxicity was evaluated by measuring the effects of PAAF lipid fraction on cell viability of hepatic and macrophage cell lines. In vivo effects on the liver were also evaluated. Effects on the inflammatory response were determined by measuring the levels of NFkB activation, the effect on the inhibitory activity of 15-deoxy-PGJ2 and the possible interference on PPARgamma activation.[Results]: High concentrations of oxidized free fatty acids were detected in PAAF. Besides the direct cell toxicity, the PAAF-derived lipid extract interfered with the anti-inflammatory pathway mediated by PPARgamma. Addition of this lipid extract to macrophage cell cultures had no direct effect on NFkB activation, but abolished the inhibitory activity of endogenous PPARgamma agonists such as 15-deoxy-PGJ2.[Conclusions]: Oxidized free fatty acids present in PAAF interfere with the endogenous regulatory mechanism of the inflammatory response, thus promoting an exacerbation of macrophage activation in acute pancreatitis.unding: This work was supported by the projects SAF2006-08449, CSIC 2006-2-0I-013 and FIS PI050599. Ciberhd is funded by the Instituto de Salud Carlos III.Peer reviewe

Estudio farmacocinético de la carboximetilcisteina 35S en la rata

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