Activation of plasminogen activator inhibitor-1 synthesis by phorbol esters in human promyelocyte HL-60--roles of PCKbeta and MAPK p42.
Thromb Haemost
; 81(3): 415-22, 1999 Mar.
Article
em En
| MEDLINE
| ID: mdl-10102471
ABSTRACT
HL-60 cells treated by PMA develop the monocyte adherent phenotype and synthesize plasminogen activator inhibitor type-1 (PAI-1). We focused our study on the identification of the PMA-activated protein kinase C (PKC) isoform and its downstream transduction pathway activating PAI-1 synthesis. Acquisition of the monocytic phenotype was evidenced by cell adherence (90-95%) and a sharp increase of CD 36 and receptor for urokinase plasminogen activator (uPAR) surface expression. Ro 31-8220, a specific inhibitor of PKC, prevented PMA-induced PAI-1 synthesis (mRNA and protein levels) and cell adhesion. To identify the PKC isoform, we took advantage of the HL-525 cell line, an HL-60 cell variant deficient in PKCbeta gene expression. This defect prevents PMA to induce the differentiation process. HL-525 stimulated by PMA did not synthesize PAI-1 nor become adherent. However, in HL-525 cells either pretreated by retinoic acid that reinduces PKCbeta gene expression or transfected with PKCbeta cDNA, PMA significantly activated PAI-1 synthesis and adhesion of cells. Immunoblotting of active Mitogen Activated Protein Kinase (MAPK) p42/p44 in HL-60 cells showed a preferential and sustained activation of the p42 isoform by PMA over the p44 isoform. Ro 31-8220 significantly attenuated this activation. PD 098059 and U0126, both highly specific MEK inhibitors, efficiently prevented PMA-induced PAI-1 synthesis (mRNA and protein levels) and cell adhesion whereas SB203580, a specific inhibitor of stress-activated MAPK p38, did not. Results obtained from HL-60 and HL-525 cells indicate that the PMA-activated transduction pathway of uPAR expression involves a PKC isoform other than PKCbeta. In conclusion, we propose that the pathway PKCbeta-MEK-MAPK p42 is a potential linear route for PAI-1 synthesis leading to morphological changes and adherence linked to PMA-induced differentiation in HL-60 cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteína Quinase C
/
Acetato de Tetradecanoilforbol
/
Carcinógenos
/
Proteínas Serina-Treonina Quinases
/
Inibidor 1 de Ativador de Plasminogênio
/
Proteína Quinase 1 Ativada por Mitógeno
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MAP Quinase Quinase Quinase 1
/
Isoenzimas
Limite:
Humans
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article