Open AccessDual regulatory effects of nitric oxide on plasminogen activator inhibitor type 1 expression in endothelial cells
Author(s) -
Swiatkowska Maria,
CierniewskaCieslak Aleksandra,
Pawlowska Zofia,
Cierniewski Czeslaw S.
Publication year - 2000
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2000.01086.x
Subject(s) - sodium nitroprusside , nitric oxide , plasminogen activator , kinase , nitric oxide synthase , plasminogen activator inhibitor 1 , downregulation and upregulation , mapk/erk pathway , microbiology and biotechnology , activator (genetics) , chemistry , signal transduction , tumor necrosis factor alpha , extracellular , protein kinase a , biology , biochemistry , endocrinology , receptor , gene
In this report we compared the mechanism by which nitric oxide (NO), generated exogenously and endogenously, affects the plasminogen activator inhibitor type 1 (PAI‐1) expression in endothelial cells. For this purpose, we stimulated the endothelial cell line EA.hy 926 with tumour necrosis factor α (TNFα) in the presence of the exogenously NO‐releasing donors, sodium nitroprusside (SNP) and S ‐nitroso‐ N ‐acetylpenicillamine, or regulators of nitric oxide synthase (NOS) inhibitor N‐nitro‐ l ‐arginine‐methyl ester hydrochloride and substrate l ‐Arg. Expression of PAI‐1 in EA.hy 926 cells was determined by measuring the level of mRNA, using relative quantitative reverse transcriptase PCR, and protein, using ELISA. In addition, we estimated the level of activation of two mitogen‐activated protein kinases (MAPKs), extracellular signal‐regulated kinase (ERK1/2) and c‐Jun N‐terminal kinase (JNK1/2), in the cells before and after treatment with TNFα, in the presence or absence of NO donors and inhibitors. In contrast to exogenously released NO that significantly reduced mostly basal PAI‐1 expression, endogenously generated NO by NOS potentiated TNFα‐induced upregulation of PAI‐1 expression. Exogenously and endogenously generated NO causes different effects on activation of the MAPKs ERK1/2 and JNK1/2. Specifically, the SNP‐released NO activates only ERK1/2, while endogenously generated NO in a pathway induced by TNFα activates both MAPKs. Thus our data indicate that due to different cellular locations and mechanisms of generation, NO may participate in various signalling pathways leading to opposite effects on PAI‐1 expression in endothelial cells.