Dexamethasone induces the expression of the mRNA of lipocortin 1 and 2 and the release of lipocortin 1 and 5 in differentiated, but not undifferentiated U‐937 cells

FEBS Letters

Raugei, Giovanni¹  Parente, Luca²  Melli, Marialuisa¹  Solito, Egle² 

[1] Departments of Molecular Biology, Sclavo Research Centre, 53100 Siena, Italy;Departments of Pharmacology, Sclavo Research Centre, 53100 Siena, Italy

关键词: Lipocortin expression;    Cell differentiation;    Dexamethasone;    Eicosanoid inhibition;    LCT;    lipocortins;    PLA2;    phospholipase A2;    PMA;    phorbol 12-myristate 13-acetate;    DEX;    dexamethasone;   

DOI  :  10.1016/0014-5793(91)81293-H

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 μM 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.

【 授权许可】

Unknown