Fluvastatin increases the expression of adhesion molecules, monocyte chemoattractant protein-1 and tissue factor in HUVEC stimulated by patient IgG fractions containing antiphospholipid antibodies Sylvie Dunoyer-Geindre,Yordanka Dimitrova, Richard J. Fish, Nathalie Satta, Guido Reber, Egbert K.O. Kruithof, Philippe de Moerloose Division of Angiology and Haemostasis, University Hospital, Geneva, and Faculty of Medicine, Geneva, Switzerland Summary The presence of antiphospholipid antibodies (APLA) is associ- ated with an increased risk of recurrent thrombosis and preg- nancy loss.APLA are able to activate endothelial cells (EC) and induce an increase in the expression of inflammatory marker proteins, such as leukocyte adhesion molecules, tissue factor or the monocyte chemoattractant protein-1 (MCP-1). Our objec- tive was to investigate the effect of statins on EC activation in- duced by APLA in vitro. IgG was purified from the plasma of six patients with APLA and from healthy controls. EC were incu- bated with patient IgG or with control IgG, in the presence or absence of 5μM of fluvastatin, and expression of the leukocyte adhesion molecules, VCAM-1 and E-selectin, analyzed by flow cytometry and by quantitative reverse transcriptase-PCR (QRT- Keywords Antiphospholipid antibodies, endothelial cells, statins, tissue fac- tor, cell adhesion molecules PCR).The expression of tissue factor and the chemokine MCP-1 was analyzed by QRT-PCR alone.Incubation of EC with patient IgG increased the expression of VCAM-1, E-selectin, tissue fac- tor and MCP-1. Prior treatment of the cells with fluvastatin further increased the expression of these proteins.The fluvasta- tin effect was reversed by co-incubation with mevalonate or ge- ranylgeranylpyrophosphate and mimicked by the geranylgeranyl transferase inhibitor GGTI-286. Our results show that in cul- tured human EC, statins increase the extent of inflammatory ac- tivation induced by APLA.This effect appears to be mediated by an inhibitory effect of statins on one or more geranylgeranylated protein(s). Thromb Haemost 2005; 93: 339-45 Endothelium andVascular Development Correspondence to: Philippe de Moerloose Unit of Haemostasis University Hospital of Geneva 24, Rue Micheli-du-Crest 1211 Geneva 14, Switzerland Tel.: 0041–22–37 29 751, Fax: 0041–22–37 29 777 E-mail: philippe.demoerloose@hcuge.ch Received May 14, 2004 Accepted after resubmission November 25, 2004 Financial support This work was supported by the Swiss National Science Foundation (3200–067746.02). Prepublished online January 7, 2005 DOI: 10.1160/TH04–05–0297 © 2005 Schattauer GmbH, Stuttgart 339 Introduction The vascular endothelium represents a dynamic barrier between blood and surrounding tissue and is a major regulator of haemos- tasis, leukocyte migration and vascular tone. In response to acti- vation by inflammatory cytokines, endothelial cells (EC) in- crease the expression of proteins involved in leukocyte recruit- ment, adhesion and transmigration leading to a proinflammatory phenotype. Among these proteins, adhesion molecules such as VCAM-1, ICAM-1 and E-selectin, or chemokines, such as monocyte chemoattractant protein-1 (MCP-1) play an important role (1, 2). In addition, expression of tissue factor is increased in activated EC (3). In patients, the presence of antiphospholipid antibodies (APLA) is associated with an increased risk of thrombosis and recurrent fetal loss. The occurrence of APLA with clinical mani- festations characterizes the antiphospholipid syndrome (APS). Several studies have shown that incubation of EC with APLA leads to an increased expression of leukocyte adhesion mol- ecules and of tissue factor, and enhance monocyte adhesion in vitro (4–6). Furthermore, in vivo, APLA increase the adhesion of leukocytes to the endothelium in the cremaster muscle microcir- culation model in mice (7, 8). In patients with APS, plasma levels of circulating markers of EC activation are increased (9, 10). These observations suggest that in vivo and in vitro APLA induce EC activation, which may contribute to their pathological ef- fects. Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are cholesterol-lowering drugs and are widely used in the treatment of hyperlipidemia to prevent cardiovascular com-