RESUMEN
Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a major deubiquitinating enzyme of the nervous system and associated with the development of neurodegenerative diseases. We have previously shown that UCH-L1 is found in tubular and parietal cells of the kidney and is expressed de novo in injured podocytes. Since the role of UCH-L1 in the kidney is unknown we generated mice with a constitutive UCH-L1-deficiency to determine its role in renal health and disease. UCH-L1-deficient mice developed proteinuria, without gross changes in glomerular morphology. Tubular cells, endothelial cells, and podocytes showed signs of stress with an accumulation of oxidative-modified and polyubiquitinated proteins. Mechanistically, abnormal protein accumulation resulted from an altered proteasome abundance leading to decreased proteasomal activity, a finding exaggerated after induction of anti-podocyte nephritis. UCH-L1-deficient mice exhibited an exacerbated course of disease with increased tubulointerstitial and glomerular damage, acute renal failure, and death, the latter most likely a result of general neurologic impairment. Thus, UCH-L1 is required for regulated protein degradation in the kidney by controlling proteasome abundance. Altered proteasome abundance renders renal cells, particularly podocytes and endothelial cells, susceptible to injury.
Asunto(s)
Glomerulonefritis/enzimología , Enfermedades del Complejo Inmune/enzimología , Podocitos/enzimología , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitina Tiolesterasa/metabolismo , Ubiquitina/metabolismo , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Glomerulonefritis/genética , Glomerulonefritis/inmunología , Glomerulonefritis/patología , Hipotensión/enzimología , Hipotensión/genética , Enfermedades del Complejo Inmune/genética , Enfermedades del Complejo Inmune/inmunología , Enfermedades del Complejo Inmune/patología , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones Noqueados , Oxidación-Reducción , Podocitos/inmunología , Podocitos/patología , Proteinuria/enzimología , Proteinuria/genética , Proteolisis , Ubiquitina Tiolesterasa/deficiencia , Ubiquitina Tiolesterasa/genética , UbiquitinaciónRESUMEN
Small vessel vasculitis is a life-threatening condition and patients typically present with renal and pulmonary injury. Disease pathogenesis is associated with neutrophil accumulation, activation, and oxidative damage, the latter being driven in large part by myeloperoxidase (MPO), which generates hypochlorous acid among other oxidants. MPO has been associated with vasculitis, disseminated vascular inflammation typically involving pulmonary and renal microvasculature and often resulting in critical consequences. MPO contributes to vascular injury by 1) catabolizing nitric oxide, impairing vasomotor function; 2) causing oxidative damage to lipoproteins and endothelial cells, leading to atherosclerosis; and 3) stimulating formation of neutrophil extracellular traps, resulting in vessel occlusion and thrombosis. Here we report a selective 2-thiouracil mechanism-based MPO inhibitor (PF-1355 [2-(6-(2,5-dimethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide) and demonstrate that MPO is a critical mediator of vasculitis in mouse disease models. A pharmacokinetic/pharmacodynamic response model of PF-1355 exposure in relation with MPO activity was derived from mouse peritonitis. The contribution of MPO activity to vasculitis was then examined in an immune complex model of pulmonary disease. Oral administration of PF-1355 reduced plasma MPO activity, vascular edema, neutrophil recruitment, and elevated circulating cytokines. In a model of anti-glomerular basement membrane disease, formerly known as Goodpasture disease, albuminuria and chronic renal dysfunction were completely suppressed by PF-1355 treatment. This study shows that MPO activity is critical in driving immune complex vasculitis and provides confidence in testing the hypothesis that MPO inhibition will provide benefit in treating human vasculitic diseases.
Asunto(s)
Acetamidas/farmacología , Inhibidores Enzimáticos/farmacología , Membrana Basal Glomerular/efectos de los fármacos , Glomerulonefritis/prevención & control , Enfermedades del Complejo Inmune/prevención & control , Peroxidasa/antagonistas & inhibidores , Pirimidinas/farmacología , Pirimidinonas/farmacología , Vasculitis/prevención & control , Animales , Membrana Basal Glomerular/patología , Glomerulonefritis/enzimología , Glomerulonefritis/inmunología , Glomerulonefritis/patología , Humanos , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/inmunología , Enfermedades del Complejo Inmune/patología , Pulmón/irrigación sanguínea , Pulmón/efectos de los fármacos , Pulmón/inmunología , Ratones , Infiltración Neutrófila/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Vasculitis/enzimología , Vasculitis/inmunología , Vasculitis/patologíaRESUMEN
AIM: Renal expression of matrix metalloproteinases (MMP) and tissue inhibitors of MMP (TIMP) contribute to the development of tubulointerstitial fibrosis characteristic of progressive forms of primary glomerulonephritis (GN). The aim of this study was to investigate the therapeutic effect of MMP inhibitor, doxycycline, administration in an experimental rat model of immune-complex nephritis (ICN). METHODS: The induction of immune-complex glomerulonephritis was carried out by the administration of an i.v. dose of 2 mg bovine serum albumin (BSA) daily for 28 days after 8 weeks of s.c. immunization with 1 mg of BSA in complete Freund's adjuvant. Doxycycline (30 mg/kg) was given daily (in groups 2 and 4) by gavage for 28 days. RESULTS: Animals treated with doxycycline showed significant reduction in glomerular area and cell proliferation than non-treated controls. Glomerular deposition of immunoglobulin (Ig)G and C3 was less intense in treated rats than non-treated controls. Although not statistically significant, interstitial inflammation was less intense in treated rats than non-treated controls. Glomerular expression of MMP-9 by immunoflourescence was significantly inhibited in the treated group. In addition pro-MMP-2 on gelatin zymography was importantly suppressed by doxycycline in ICN. CONCLUSION: Doxycycline, in addition to its antibiotic property, may, following further investigation, provide a possible survival benefit in proliferative glomerulonephritis.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Doxiciclina/farmacología , Glomerulonefritis/prevención & control , Enfermedades del Complejo Inmune/prevención & control , Glomérulos Renales/efectos de los fármacos , Inhibidores de la Metaloproteinasa de la Matriz , Inhibidores de Proteasas/farmacología , Animales , Colágeno Tipo IV/metabolismo , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Técnica del Anticuerpo Fluorescente , Adyuvante de Freund , Glomerulonefritis/inducido químicamente , Glomerulonefritis/enzimología , Glomerulonefritis/patología , Enfermedades del Complejo Inmune/inducido químicamente , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/patología , Inmunohistoquímica , Glomérulos Renales/enzimología , Glomérulos Renales/patología , Masculino , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Ratas , Ratas Wistar , Albúmina Sérica Bovina , Factores de Tiempo , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/metabolismoRESUMEN
Mast cells exert protective effects in experimental antiglomerular basement membrane-induced glomerulonephritis (GN), yet the responsible mediators have not been identified. In this study, we investigated the role of mouse mast cell protease (mMCP)-4, the functional homolog of human chymase, using mMCP-4-deficient mice. Compared with wild type animals, mMCP-4-deficient mice exhibited lower proteinuria, blood creatinine, and blood urea nitrogen levels, indicating an aggravating role of mMCP-4. Kidney histology confirmed less severe renal damage in mMCP-4-deficient mice with reduced deposits, glomerular and interstitial cellularity, and fibrosis scores. High amounts of mMCP-4 were detected in renal capsules, but not in the whole kidney, from wild type mice. Its expression in renal capsules was markedly decreased after GN induction, suggesting that locally released enzyme by degranulated mast cells could contribute to the functional and physiopathological hallmarks of GN. Supporting a proinflammatory role, glomerular and interstitial macrophage and T cell infiltration, levels of proinflammatory TNF and MCP-1 mRNA, and the expression of the profibrotic peptide angiotensin II together with type I collagen were markedly downregulated in kidneys of mMCP-4-deficient mice. We conclude that mMCP-4 chymase, contrary to the global anti-inflammatory action of mast cells, aggravates GN by promoting kidney inflammation. These results highlight the complexity of mast cell-mediated inflammatory actions and suggest that chymase inhibition may represent a novel therapeutic target in GN.
Asunto(s)
Enfermedad por Anticuerpos Antimembrana Basal Glomerular/enzimología , Enfermedad por Anticuerpos Antimembrana Basal Glomerular/patología , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/patología , Mediadores de Inflamación/fisiología , Serina Endopeptidasas/fisiología , Animales , Enfermedad por Anticuerpos Antimembrana Basal Glomerular/inmunología , Células Cultivadas , Fibrosis , Enfermedades del Complejo Inmune/inmunología , Pruebas de Función Renal , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones TransgénicosRESUMEN
Neutrophil-derived serine proteases play an important role in fighting infections. However, emerging data suggest that these proteases also regulate noninfectious inflammatory responses. Loss-of-function mutations in serine proteases have provided critical insights into the significance of these serine proteases in initiating and amplifying immune complex-mediated diseases.
Asunto(s)
Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/inmunología , Neutrófilos/enzimología , Neutrófilos/inmunología , Serina Endopeptidasas/inmunología , Animales , Movimiento Celular , Quimiotaxis de Leucocito , Gránulos Citoplasmáticos/enzimología , Humanos , Infecciones/enzimología , Infecciones/inmunología , Inflamación/enzimología , Inflamación/inmunología , RatonesRESUMEN
Dipeptidyl peptidase IV (DPPIV) is widely expressed in many tissues; however, its precise biological function is poorly understood. One of its possible physiologic roles is an involvement in the immune system, which plays a pivotal role in the pathogenesis of glomerulonephritis. The present study focused on the involvement of DPPIV in immune complex-mediated glomerulonephritis. Experimental nephritis was induced by anti-Thy-1.1 monoclonal antibody E30 using Wistar or F344 rats. The application of a new monoclonal antibody against DPPIV, F16, completely suppressed E30-induced proteinuria and mesangial proliferation in Wistar rats, whereas these preventive effects of F16 were not observed in F344 rats, which spontaneously lack DPPIV protein. Treatment with F16 inhibited glomerular deposition of complement C3 and complement C4 after the binding of E30 to the mesangial cell surface. Because the preventive effect of F16 was attributable to suppression of the complement cascade, we examined its influences on complement-dependent mesangial cell lysis in vitro. We discovered that the complement cascade was markedly inactivated in F16-treated Wistar rat serum but not in F16-treated F344 rats. These results indicate that DPPIV may play a somewhat crucial role in regulating the complement cascade and that inhibition of DPPIV may serve as a new target for preventing complement-dependent tissue injury.
Asunto(s)
Dipeptidil Peptidasa 4/biosíntesis , Glomerulonefritis/enzimología , Enfermedades del Complejo Inmune/enzimología , Animales , Anticuerpos Bloqueadores/farmacología , Complejo Antígeno-Anticuerpo/inmunología , Sitios de Unión/efectos de los fármacos , División Celular/efectos de los fármacos , Complemento C3/metabolismo , Complemento C4/metabolismo , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Citotoxicidad Inmunológica , Dipeptidil Peptidasa 4/inmunología , Mesangio Glomerular/citología , Mesangio Glomerular/inmunología , Glomerulonefritis/inmunología , Enfermedades del Complejo Inmune/inmunología , Enfermedades del Complejo Inmune/prevención & control , Isoanticuerpos/administración & dosificación , Masculino , Proteinuria/prevención & control , Ratas , Ratas Endogámicas F344 , Ratas Wistar , Especificidad de la EspecieRESUMEN
Matrix metalloproteases (MMPs) are a group of zinc-dependent endopeptidases that can degrade every component of the extracellular matrix. Under normal circumstances, the levels of MMPs are tightly regulated at both transcriptional and posttranscriptional levels. However, they are up-regulated in pathological states such as inflammation. Previous investigations have suggested that MMP-12 (metalloelastase) may be an important mediator in the pathogenesis of chronic lung injury. In this study we investigated the role of metalloelastase in the pathogenesis of acute lung injury using mice containing a targeted disruption of the metalloelastase gene. Neutrophil influx into the alveolar space in metalloelastase-deficient animals was reduced to approximately 50% of that observed in parent strain mice following the induction of injury by immune complexes. In addition, lung permeability in metalloelastase-deficient mice was approximately 50% of that of injured parent strain animals with normal levels of metalloelastase and this was correlated with histological evidence of less lung injury in the metalloelastase-deficient animals. Collectively, the data suggest that metalloelastase is necessary for the full development of acute alveolitis in this model of lung injury. Further, the data suggest that reduced injury in metalloelastase-deficient mice is due in part to decreased neutrophil influx into the alveolar space.
Asunto(s)
Enfermedades del Complejo Inmune/enzimología , Enfermedades Pulmonares/enzimología , Enfermedades Pulmonares/inmunología , Metaloendopeptidasas/fisiología , Enfermedad Aguda , Animales , Líquido del Lavado Bronquioalveolar/citología , Recuento de Leucocitos , Pulmón/patología , Enfermedades Pulmonares/patología , Metaloproteinasa 12 de la Matriz , Metaloproteinasa 2 de la Matriz/fisiología , Metaloproteinasa 9 de la Matriz/fisiología , Metaloendopeptidasas/genética , Ratones , Ratones Noqueados , Infiltración NeutrófilaRESUMEN
The involvement of immune complexes during experimental arthritis in induction of metalloproteinases (MMP)-induced neoepitopes in aggrecan in cartilage, as well as the role of stromelysin-1 (SLN-1) in the induction of this neoepitope, was investigated. Passive immune complex arthritis was induced, and generation of the MMP-specific cleavage product (VDIPEN) was studied by immunolocalization. The role of SLN-1 was studied with use of SLN-1-deficient (SLN-1KO) mice. VDIPEN expression was studied in vitro by exposing the cartilage to IL-1 and subsequent activation of latent MMPs. Immune complex arthritis was characterized by an acute inflammation, with influx of mainly polymorphonuclear cells into the joint cavity. Expression of VDIPEN neoepitopes was consistently found in areas extensively depleted from proteoglycans. SLN-1KO mice did not show expression of the VDIPEN neoepitope, although inflammation and proteoglycan depletion was comparable to wild-type mice. In addition, erosions of cartilage were absent in SLN-1KO mice, but were present in wild-type mice, suggesting an important role for SLN-1 in cartilage destruction. In vitro studies showed that SLN-1 is also pivotally involved in IL-1-induced MMP activity. Stimulated polymorphonuclear neutrophils were able to activate latent MMPs present in the cartilage. Neutrophil elastase was also capable of activating IL-1-induced latent MMPs, which identifies elastase as a possible activator for latent VDIPEN-inducing MMPs. This study suggests that IC are important in the activation of latent MMPs in cartilage, possibly through polymorphonuclear neutrophil activation on the cartilage edge. SLN-1 is a pivotal enzyme in overall MMP-activity in cartilage during immune complex-mediated arthritis.
Asunto(s)
Artritis/enzimología , Artritis/inmunología , Cartílago Articular/enzimología , Enfermedades del Complejo Inmune/enzimología , Metaloproteinasa 3 de la Matriz/fisiología , Animales , Artritis/genética , Artritis/patología , Cartílago Articular/patología , Activación Enzimática/genética , Activación Enzimática/inmunología , Epítopos/biosíntesis , Enfermedades del Complejo Inmune/genética , Enfermedades del Complejo Inmune/inmunología , Enfermedades del Complejo Inmune/patología , Interleucina-1/farmacología , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Ratones , Ratones Congénicos , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/enzimología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Oligopéptidos/biosíntesis , Fragmentos de Péptidos/biosíntesisRESUMEN
Previous studies have shown high arginase activity at inflammatory sites. Arginase converts L-arginine to L-ornithine, sharing a common substrate with nitric oxide synthase. It exists as two isoforms, AI and AII. While the function of liver arginase (AI) in ureagenesis has been defined, the role and isoform of arginase in cells without a complete urea cycle are unknown. We therefore determined arginase isoform mRNA expression in glomerular acute immune complex inflammation, and its cultured constituent cells. AI was induced in nephritic glomeruli, and in mesangial cells stimulated with IL-4 and cAMP, and was present in elicited neutrophils and macrophages. AII was constitutively expressed. Our data strongly suggest that AI, thought to be restricted to the liver, accounts for high arginase activity at inflammatory sites where it may limit high output nitric oxide production and generate polyamines and proline essential for cell proliferation and matrix production. This identification of AI in inflamed tissue is an important step for understanding the consequences of increased arginase activity.
Asunto(s)
Arginasa/biosíntesis , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/patología , Regulación hacia Arriba/inmunología , Enfermedad Aguda , Animales , Mesangio Glomerular/enzimología , Glomerulonefritis/enzimología , Glomerulonefritis/patología , Inflamación/enzimología , Inflamación/inmunología , Isoenzimas/biosíntesis , Glomérulos Renales/enzimología , Glomérulos Renales/patología , Macrófagos/enzimología , Masculino , Neutrófilos/enzimología , Ratas , Ratas Endogámicas LewRESUMEN
Kidney ectopeptidases play an important role in the metabolism of different peptides. They activate precursor proteins or inactivate peptides including hormones, cytokines, vasoactive peptides (angiotensin II, endothelin), neuroendocrine hormones, changing local concentration in active peptides. Kidney ectopeptidase regulate cell proliferation, adhesion, matrix synthesis, cell signaling, cell activation, differentiation and cell-cell communication. The role of four major ectopeptidases (aminopeptidase A and N, dipeptidylpeptidase IV, and neutral endopeptidase) is presented.
Asunto(s)
Endopeptidasas/fisiología , Riñón/enzimología , Aminopeptidasas/fisiología , Animales , Antígenos CD13/fisiología , Citocinas/fisiología , Dipeptidil Peptidasa 4/fisiología , Modelos Animales de Enfermedad , Endopeptidasas/química , Inducción Enzimática , Glomerulonefritis/enzimología , Glomerulonefritis/inmunología , Glutamil Aminopeptidasa , Hormonas/metabolismo , Humanos , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/inmunología , Enfermedades Renales/enzimología , Nefritis Lúpica/enzimología , Ratones , Neprilisina/fisiología , Péptidos/metabolismo , Inhibidores de Proteasas/farmacología , Precursores de Proteínas/metabolismo , Ratas , Ratas Endogámicas LewRESUMEN
Neutrophils play an important part in the development of acute inflammatory injury. Human neutrophils contain high levels of the serine protease elastase, which is stored in azurophilic granules and is secreted in response to inflammatory stimuli. Elastase is capable of degrading many components of extracellular matrix [1-4] and has cytotoxic effects on endothelial cells [5-7] and airway epithelial cells. Three types of endogenous protease inhibitors control the activity of neutrophil elastase, including alpha-1 protease inhibitor (alpha-1PI), alpha-2 macroglobulin and secreted leukoproteinase inhibitor (SLPI) [8-10]. A disturbed balance between neutrophil elastase and these inhibitors has been found in various acute clinical conditions (such as adult respiratory syndrome and ischemia-reperfusion injury) and in chronic diseases. We investigated the effect of NX21909, a selected oligonucleotide (aptamer) inhibitor of elastase, in an animal model of acute lung inflammatory disease [11-14]. This inhibitor was previously selected from a hybrid library of randomized DNA and a small-molecule irreversible inhibitor of elastase (a valine diphenyl ester phosphonate, Fig. 1), by the blended SELEX process [15]. We show that NX21909 inhibits lung injury and neutrophil influx in a dose-dependent manner, the first demonstration of efficacy by an aptamer in an animal disease model.
Asunto(s)
Elastasa de Leucocito/antagonistas & inhibidores , Pulmón/enzimología , Pulmón/patología , Neutrófilos/enzimología , Oligodesoxirribonucleótidos/uso terapéutico , Oligonucleótidos/uso terapéutico , Inhibidores de Serina Proteinasa/uso terapéutico , Valina/análogos & derivados , Animales , Permeabilidad Capilar/inmunología , Movimiento Celular/efectos de los fármacos , Movimiento Celular/inmunología , Enfermedades del Complejo Inmune/tratamiento farmacológico , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/fisiopatología , Inflamación/tratamiento farmacológico , Inflamación/enzimología , Inflamación/fisiopatología , Pulmón/fisiopatología , Masculino , Neutrófilos/inmunología , Oligonucleótidos/química , Ratas , Ratas Endogámicas , Inhibidores de Serina Proteinasa/química , Valina/química , Valina/uso terapéuticoRESUMEN
Passively released or actively secreted elastase from neutrophils has been linked to the pathologic processes of a variety of inflammatory diseases, including idiopathic pulmonary fibrosis, rheumatoid arthritis, adult respiratory distress syndrome, and cystic fibrosis. The serine proteinase has a broad substrate specificity and may attack a number of host proteins outside of the neutrophil, including lung elastin and fibronectin. Such a proteolysis may change the normal surrounding tissue and the protein pattern of an inflammatory focus. Additionally, it acts as a potent secretagogue in minute amounts. The reason that neutrophil elastase is present in considerable concentrations outside of the neutrophil during chronic inflammation and that the major endogenous serine proteinase inhibitor for neutrophil elastase, alpha 1-proteinase inhibitor, is easily inactivated by proteolytic and oxidative attack is unclear. Released neutrophil elastase may also be involved in regulating chronic inflammation. In a feedback mechanism, neutrophil elastase inhibits neutrophil stimulation and concomitant elastase release by cleavage of immunoglobulins, complement components, and complement receptor type 1 on neutrophils. Besides a number of harmful effects of neutrophil elastase in inflammation, the latter mechanism, although considerably impairing phagocytosis, may be beneficial particularly in the light of persistent bacterial pathogens in the human lung affected by cystic fibrosis.
Asunto(s)
Inflamación/enzimología , Enfermedades Pulmonares/enzimología , Elastasa Pancreática/fisiología , Animales , Enfermedad Crónica , Fibrosis Quística/enzimología , Exocitosis , Humanos , Enfermedades del Complejo Inmune/enzimología , Elastasa de Leucocito , FagocitosisRESUMEN
1. The ability of analogues of L-arginine (N-iminoethyl-L-ornithine (L-NIO), NG-monomethyl-L-arginine (L-NMMA), NG-nitro-L-arginine methyl ester (L-NAME) and NG-nitro-L-arginine (L-NNA)) to protect against inflammatory injury induced by activated neutrophils was investigated in rats following intradermal or intrapulmonary deposition of immune complexes. 2. The descending order of potency for protective effects of these analogues was: L-NIO > L-NMMA > L-NNA = L-NAME. The approximate IC50 value for L-NIO in the dermal vasculitis model was 65 microM. For all other compounds, the IC50 values were > 5 mM. 3. The protective effect of L-NIO in the skin was reversed in a dose-dependent manner by the presence of L-arginine, but not by D-arginine. L-Arginine also reversed the protective effects of L-NIO in immune complex-induced lung injury. 4. The protective effects of L-NIO were not associated with reductions in neutrophil accumulation, as measured by extraction from tissues of myeloperoxidase. 5. These data demonstrate that L-NIO has the most potent protective effects against immune complex-induced vascular injury induced by activated macrophages. Furthermore, they indicate that this injury is dependent upon the generation of nitric oxide.
Asunto(s)
Aminoácido Oxidorreductasas/antagonistas & inhibidores , Enfermedades del Complejo Inmune/prevención & control , Vasculitis Leucocitoclástica Cutánea/prevención & control , Alveolitis Alérgica Extrínseca/enzimología , Alveolitis Alérgica Extrínseca/prevención & control , Animales , Arginina/análogos & derivados , Arginina/farmacología , Enfermedades del Complejo Inmune/enzimología , Masculino , NG-Nitroarginina Metil Éster , Óxido Nítrico Sintasa , Nitroarginina , Ornitina/análogos & derivados , Ornitina/farmacología , Peroxidasa/metabolismo , Ratas , Vasculitis Leucocitoclástica Cutánea/enzimología , omega-N-MetilargininaRESUMEN
Activated leukocytes in the peritoneal cavity have been shown to release phospholipase A2(PLA2) activity and increased production of eicosanoids. It is not known whether a similar phenomenon occurs in inflammatory bowel diseases. We measured PLA2 activity in the peritoneal leukocytes and eicosanoid content in the peritoneal cavity of rats with experimental colitis induced by dinitrochlorobenzene, immune complex-mediated colitis, and acetic acid-induced colitis. In all models of colitis, proteins in the peritoneal cavity were increased by 60-260% above control, leukocyte number was elevated by 3- to 10-fold, the PLA2 activity by 4- to 32-fold, and anti-PLA2 activity was absent. Eicosanoid concentrations were 3- to 4-fold higher than controls. In vitro studies confirmed that the peritoneal leukocytes were the source of PLA2. Treatment of rats with dexamethasone and leukocytes in vitro reduced PLA2 significantly, but they were well above control rats without colitis. However, dexamethasone did not improve the histology. These studies suggest that peritoneal leukocytes may serve as an additional source of inflammatory mediators, which may further enhance the inflammatory response in the rat colon.
Asunto(s)
Colitis/enzimología , Leucocitos/enzimología , Fosfolipasas A/análisis , Acetatos/toxicidad , Ácido Acético , Animales , Reacción de Arthus , Colitis/inducido químicamente , Colitis/inmunología , Dexametasona/farmacología , Dexametasona/uso terapéutico , Dinitroclorobenceno , Modelos Animales de Enfermedad , Eicosanoides/biosíntesis , Hipersensibilidad Tardía/complicaciones , Enfermedades del Complejo Inmune/enzimología , Enfermedades Inflamatorias del Intestino , Recuento de Leucocitos , Masculino , Cavidad Peritoneal/citología , Fosfolipasas A2 , Ratas , Ratas EndogámicasRESUMEN
Biochemical changes in plasma and urine were monitored in six cats before and during the induction of immune complex-mediated glomerulonephritis (ICGN) by daily intravenous administration of human serum albumin (HSA). The earliest indication of renal dysfunction in the cats was hypoalbuminaemia, which occurred as early as 13 weeks before cats developed clinical signs of renal disease. Proteinuria occurred 2 to 3 weeks before clinical disease, but was sensitive in predicting renal pathology in two cats that did not develop clinical signs of disease. In addition, increased activities of several urinary enzymes were detected in affected cats, with measurement of N-acetyl-beta-D-glucosaminidase and gamma-glutamyl transferase providing the earliest and most sensitive indication of renal damage. These plasma and urine measurements correlated more closely with the renal pathology, observed at postmortem, than clinical assessment of disease. It was concluded that ICGN in the cat could be diagnosed earliest by measurement of plasma protein concentration, whilst disease progress could be effectively monitored by including assays to measure urine protein and urine enzymes.
Asunto(s)
Enfermedades de los Gatos/sangre , Glomerulonefritis/veterinaria , Enfermedades del Complejo Inmune/veterinaria , Animales , Enfermedades de los Gatos/enzimología , Enfermedades de los Gatos/orina , Gatos , Glomerulonefritis/sangre , Glomerulonefritis/enzimología , Glomerulonefritis/orina , Enfermedades del Complejo Inmune/sangre , Enfermedades del Complejo Inmune/enzimología , Enfermedades del Complejo Inmune/orina , Proteinuria/veterinariaRESUMEN
In sputa of 21 cystic fibrosis patients suffering from chronic Pseudomonas aeruginosa lung infections, activities of lysosomal proteases released from polymorphonuclear leukocytes (PMN) and immune complexes were quantitatively determined. The results showed that low immune complex values correlated with high protease activities and vice versa. In a longitudinal study fluctuating, reciprocal changes of the parameters were observed. Therefore, the hypothesis was investigated as to whether PMN elastase cleaves immune complexes and regulates inflammation. It was shown that treatment of immune complex-positive sputa with PMN elastase decreased IgG and IgA immune complex values and lead to cleavage of the immunoglobulins in the hinge region. PMN elastase-treated samples were not able to stimulate the oxidative burst of PMN. Cleavage of in vitro built immune complexes did not lead to liberation of bound antigen. Western blot analysis of one sputum sample revealed split products of the IgG heavy chain. The results suggest that PMN elastase splits off the Fc portion of immunoglobulins in immune complexes and thus regulates inflammation by a feedback mechanism leading to cyclic inflammatory states.
Asunto(s)
Enfermedades del Complejo Inmune/enzimología , Neutrófilos/enzimología , Elastasa Pancreática/inmunología , Complejo Antígeno-Anticuerpo/inmunología , Fibrosis Quística/enzimología , Fibrosis Quística/inmunología , Humanos , Elastasa Pancreática/análisisAsunto(s)
Proteínas Inactivadoras del Complemento 1/sangre , Inhibidores de Proteasas , Trombosis/enzimología , Animales , Antitrombinas/síntesis química , Proteínas Inactivadoras del Complemento 1/antagonistas & inhibidores , Fibrinólisis , Humanos , Enfermedades del Complejo Inmune/enzimología , Inflamación/enzimología , Modelos BiológicosRESUMEN
By means of a biological assay the collagenolytic activity of kidneys from rats with experimental immune complex glomerulonephritis and control animals was tested. We detected collagenolysis in both panels but found quantitative differences in the collagenase activity. The enzymatic collagenolysis was significantly increased (P less than 0.001) in the nephritic kidneys. From the fact that the chelating agent EDTA inhibited potentially the released enzyme it can be concluded that the origin is the polymorphonuclear granules.
Asunto(s)
Glomerulonefritis/enzimología , Enfermedades del Complejo Inmune/enzimología , Riñón/enzimología , Colagenasa Microbiana/metabolismo , Animales , Ácido Edético/farmacología , Glomerulonefritis/inmunología , Ratas , Albúmina Sérica BovinaRESUMEN
The lysosomal enzyme beta glucuronidase was selectively released from leukocytes when these were incubated with insoluble immnue complexes and also from the leukocytes of patients with immune complex disease when these were incubated with their own plasma.
Asunto(s)
Complejo Antígeno-Anticuerpo , Glucuronidasa/metabolismo , Leucocitos/enzimología , Humanos , Enfermedades del Complejo Inmune/enzimología , Leucocitos/inmunología , Enfermedades de la Piel/enzimología , Enfermedades de la Piel/inmunologíaRESUMEN
In characterizing the immunochemical and biochemical nature of middle ear effusions (MEE) of chronic serous otitis media (SOM), we have previously shown that MEE contain all major immunoglobulin classes, increased levels of several lysosomal enzymes, decreased total complement, but increased levels of C3. This report extends these observations by showing that MEE also contains C3 proactivator (C3PA) that can be activated by those organisms involved in acute otitis media, which confirms a functional alternate complement pathway. Furthermore, we have demonstrated the presence of soluble immune complexes in MEE using the Raji cell test. These data further support an immune complex mediated etiopathogenesis for chronic SOM.