RESUMO
11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is implicated in the etiology of metabolic syndrome. We previously showed that pharmacological inhibition of 11ß-HSD1 ameliorated multiple facets of metabolic syndrome and attenuated atherosclerosis in ApoE-/- mice. However, the molecular mechanism underlying the atheroprotective effect was not clear. In this study, we tested whether and how 11ß-HSD1 inhibition affects vascular inflammation, a major culprit for atherosclerosis and its associated complications. ApoE-/- mice were treated with an 11ß-HSD1 inhibitor for various periods of time. Plasma lipids and aortic cholesterol accumulation were quantified. Several microarray studies were carried out to examine the effect of 11ß-HSD1 inhibition on gene expression in atherosclerotic tissues. Our data suggest 11ß-HSD1 inhibition can directly modulate atherosclerotic plaques and attenuate atherosclerosis independently of lipid lowering effects. We identified immune response genes as the category of mRNA most significantly suppressed by 11ß-HSD1 inhibition. This anti-inflammatory effect was further confirmed in plaque macrophages and smooth muscle cells procured by laser capture microdissection. These findings in the vascular wall were corroborated by reduction in circulating MCP1 levels after 11ß-HSD1 inhibition. Taken together, our data suggest 11ß-HSD1 inhibition regulates proinflammatory gene expression in atherosclerotic tissues of ApoE-/- mice, and this effect may contribute to the attenuation of atherosclerosis in these animals.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Aterosclerose/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Vasculite/tratamento farmacológico , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Animais , Apolipoproteínas E/genética , Aterosclerose/etiologia , Colesterol/metabolismo , Perfilação da Expressão Gênica , Genes MHC da Classe II/genética , Glucocorticoides/metabolismo , Microdissecção e Captura a Laser , Lipídeos/sangue , Camundongos , Camundongos Knockout , Análise em Microsséries , Vasculite/complicaçõesRESUMO
A nonpeptidyl small molecule antagonist, compound A, to nonactivated very late antigen-4 (VLA4) was examined in lung inflammation induced by a single dose of ovalbumin challenge. Compound A presented a good pharmacokinetic property, when given intratracheally, and the blood cells from such pharmacokinetic study showed good receptor occupancy of the compound for approximately 8 hours. Compound A was then tested in an ovalbumin-induced airway inflammation model by intranasal or intravenous route of administration. There was a dose-dependent inhibition of eosinophilia in the bronchiolar lavage fluid, when compound A was given intranasally but not when it was given intravenously. For comparison, antibody to VLA4 and another compound, BIO1211, which reacts only with activated VLA4, were examined in this system. Immunohistochemical analyses of the lung tissue substantiated the findings in the bronchiolar lavage fluid. Specific staining of the major basic protein of eosinophils showed peribronchiolar infiltration of eosinophils. Some of these eosinophils were also positive for nitrotyrosine, suggesting activation of eosinophils in the lung interstitium. There was deposition of major basic protein and nitrotyrosine at the base of the perivascular endothelium, indicative of degranulation of eosinophils in the area. After intranasal treatment with compound A, eosinophils in the lungs and their activation products were substantially decreased, documenting its effectiveness in inhibiting lung inflammation.