Glucocorticoids inhibit inducible-type NO synthase activity in a variety of cell types. We report here that proteins recovered from the medium of dexamethasone-treated J774 macrophages (1, 10, 100 microg/ml) inhibited lipopolysaccharide-stimulated nitrite generation by 10.0 +/- 3.0\%, 32.3 +/- 5.3\% and 55.0 +/- 6.0\%, respectively, and inducible NO synthase mRNA expression in these cells. Immunoblotting analysis of crude and partially purified glucocorticoid-induced proteins with an anti-lipocortin-1 polyclonal antiserum revealed the presence of lipocortin-1-like immunoreactive species with a molecular mass of 35-37 kDa. Furthermore, inhibition of lipopolysaccharide-induced nitrite production by glucocorticoid-induced proteins in J774 cells was reversed by addition of anti-lipocortin-1 neutralizing polyclonal antibody (1:60 dilution; 4 h before lipopolysaccharide). Comparison of glucocorticoid-induced proteins inhibition of both nitrite production and inducible NO synthase mRNA expression suggests that these effects result mainly from inhibition of lipopolysaccharide-mediated inducible NO synthase gene expression. These results indicate that negative regulation of inducible NO synthase by glucocorticoids is, at least in part, mediated by glucocorticoid-induced proteins that involve also members of the lipocortin-like superfamily.
Inhibition of inducible nitric oxide synthase gene expression by glucocorticoid-induced protein(s) in lipopolysaccharide-stimulated J774 cells / F., D'Acquisto; L., Cicatiello; Iuvone, Teresa; Ialenti, Armando; Ianaro, Angela; H., Esumi; A., Weisz; Carnuccio, Rosa. - In: EUROPEAN JOURNAL OF PHARMACOLOGY. - ISSN 0014-2999. - STAMPA. - 339:(1997), pp. 87-95.
Inhibition of inducible nitric oxide synthase gene expression by glucocorticoid-induced protein(s) in lipopolysaccharide-stimulated J774 cells.
IUVONE, TERESA;IALENTI, ARMANDO;IANARO, ANGELA;CARNUCCIO, ROSA
1997
Abstract
Glucocorticoids inhibit inducible-type NO synthase activity in a variety of cell types. We report here that proteins recovered from the medium of dexamethasone-treated J774 macrophages (1, 10, 100 microg/ml) inhibited lipopolysaccharide-stimulated nitrite generation by 10.0 +/- 3.0\%, 32.3 +/- 5.3\% and 55.0 +/- 6.0\%, respectively, and inducible NO synthase mRNA expression in these cells. Immunoblotting analysis of crude and partially purified glucocorticoid-induced proteins with an anti-lipocortin-1 polyclonal antiserum revealed the presence of lipocortin-1-like immunoreactive species with a molecular mass of 35-37 kDa. Furthermore, inhibition of lipopolysaccharide-induced nitrite production by glucocorticoid-induced proteins in J774 cells was reversed by addition of anti-lipocortin-1 neutralizing polyclonal antibody (1:60 dilution; 4 h before lipopolysaccharide). Comparison of glucocorticoid-induced proteins inhibition of both nitrite production and inducible NO synthase mRNA expression suggests that these effects result mainly from inhibition of lipopolysaccharide-mediated inducible NO synthase gene expression. These results indicate that negative regulation of inducible NO synthase by glucocorticoids is, at least in part, mediated by glucocorticoid-induced proteins that involve also members of the lipocortin-like superfamily.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.