Influence of the 4G/5G PAI-1 genotype on angiotensin II-stimulated human endothelial cells and in patients with hypertension.
BACKGROUND
We examined the influence of the 4G/5G PAI-1 (plasminogen activator inhibitor) genotype on Angiotensin II (Ang II)-induced PAI-1 expression by human endothelial cells (HUVEC) in the presence and absence of AT1-receptor blocker losartan, and screened for this polymorphism in relation to plasma PAI-1 and arterial pressure in apparently healthy subjects.


RESULTS
Genotyped cultured HUVEC were incubated with Ang II (10(-8) M) with or without losartan up to 24 h. PAI-1 mRNA was determined in cell extracts and protein and activity assessed in supernatants and extracellular matrix (ECM). Ang II increased PAI-1 mRNA and activity in a genotype-dependent manner, higher values observed for 4G/4G HUVEC compared with 4G/5G and 5G/5G genotypes (p<0.05). Laser confocal microscopy and Western blot analysis showed increased PAI-1 protein within ECM in Ang II-stimulated cultures. PAI-1 expression and protein secretion induced by Ang II in 4G/4G HUVEC was completely inhibited by preincubation with 0.05 microM losartan (p<0.01), indicating an AT1-mediated effect. In a group of hypertensives homozygous for the 4G allele, PAI-1 antigen was significantly increased (51.0+/-10.1 ng/ml) compared with normotensives (28.3+/-4.0 ng/ml) and hypertensives carrying the 5G allele (p<0.05).


CONCLUSIONS
The 4G/5G PAI-1 polymorphism determines the endothelial PAI-1 upregulation by Ang II and the inhibitory response to losartan. Analysis of PAI-1 genotypes may help identifying subgroups of hypertensives at higher cardiovascular risk.
Roncal
C
C
School of Medicine, University of Navarra, 31080-Pamplona, Spain.
Orbe
J
J
Rodriguez
J A
JA
Belzunce
M
M
Beloqui
O
O
Diez
J
J
Páramo
J A
JA
D000704:Analysis of Variance; D000804:Angiotensin II / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers; D016022:Case-Control Studies; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D005342:Fibrinolysis; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D006973:Hypertension / Q000378:metabolism*; D019808:Losartan / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D011110:Polymorphism, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical
D047228:Angiotensin II Type 1 Receptor Blockers; D005819:Genetic Markers; D017395:Plasminogen Activator Inhibitor 1; D000804:Angiotensin II; D019808:Losartan