Original article Suppression of inflammatory signaling in monocytes from patients with coronary artery disease Stephan H. Schirmer a,d, ⁎, Joost O. Fledderus b , Anja M. van der Laan a , Tineke C.T.M. van der Pouw-Kraan e , Perry D. Moerland c , Oscar L. Volger e , Josefien M. Baggen e , Michael Böhm d , Jan J. Piek a , Anton J.G. Horrevoets b,e , Niels van Royen a a Department of Cardiology, Academic Medical Center, University of Amsterdam,1105AZ Amsterdam, The Netherlands b Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam,1105AZ Amsterdam, The Netherlands c Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics Academic Medical Center, University of Amsterdam,1105AZ Amsterdam, The Netherlands d Klinik für Innere Medizin III (Kardiologie, Angiologie und Internistische Intensivmedizin), Universitätsklinikum des Saarlandes, 66421 Homburg/Saar, Germany e Department of Molecular Cell Biology and Immunology, VU University Medical Center, 1081BT Amsterdam, The Netherlands abstract article info Article history: Received 6 July 2008 Received in revised form 28 October 2008 Accepted 29 October 2008 Available online 14 November 2008 Keywords: Atherosclerosis Monocytes Gene expression Inflammation Activation Vascular biology Monocytes and T-cells play an important role in the development of atherosclerotic coronary artery disease (CAD). Transcriptome analysis of circulating mononuclear cells from carefully matched atherosclerotic and control patients will potentially provide insights into the pathophysiology of atherosclerosis and supply biomarkers for diagnostic purposes. From patients undergoing coronary angiography because of anginal symptoms, we carefully matched 18 patients with severe triple-vessel CAD to 13 control patients without angiographic signs of CAD. All patients were on statin and aspirin treatment. Elevated soluble-ICAM levels demonstrated increased vascular inflammation in atherosclerotic patients. RNA from circulating CD4+ T-cells, CD14+ monocytes, lipopolysaccharide-stimulated monocytes, and macrophages was subjected to genome- wide expression analysis. In CD14+ monocytes, few inflammatory genes were overexpressed in control patients, while atherosclerotic patients showed overexpression of a group of Krüppel-associated box - containing transcription factors involved in negative regulation of gene expression. These differences disappeared upon LPS-stimulation or differentiation towards macrophages. No consistent changes in T cell transcriptomes were detected. Large inter-individual variability prevented the use of single differentially expressed genes as biomarkers, while monocyte gene expression signature predicted patient status with an accuracy of 84%. In this comprehensive analysis of circulating cell transcriptomes in atherosclerotic CAD, cautious patient matching revealed only small differences in transcriptional activity in different mononuclear cell types. Only an indication of a negative feedback to inflammatory gene expression was detected in atherosclerotic patients. Transcriptome differences of circulating cells possibly play less of a role than hitherto thought in the individual patient's susceptibility to atherosclerotic CAD, when appropriately matched for clinical symptoms and medication taken. © 2008 Elsevier Inc. All rights reserved. 1. Introduction Apart from classical risk factors, individual susceptibility to atherosclerotic disease is also influenced by functional differences of circulating cells [1]. Both monocytes and T-cells are known to elicit pathogenic immune responses in the vascular wall, contributing to the local inflammatory environment [2]. Experimental models have shown that impaired monocyte chemoattraction results in reduced atherosclerosis [3,4], while monocyte activation leads to accelerated atherosclerosis [5]. A recent clinical study has shown differences in monocyte gene expression between patients undergoing carotid endarterectomy compared with controls using serial analysis of gene expression (SAGE) [6]. SAGE was, however, only performed in a small number of patients, and controls were not matched by symptoms and medica- tion. In another study, differential expression of CD44 has been demonstrated on monocyte-derived macrophages from patients with atherosclerotic disease versus controls [7]. Gene expression analysis has particularly been used in hematological disorders for diagnostic and therapeutic purposes [8 ,9 ]. It is conceivable that differential gene expression separates patients with overt atherosclerotic disease from individuals with low atherosclerotic burden. Investigation of mononuclear cell gene expression could provide new insights into the pathophysiology of the Journal of Molecular and Cellular Cardiology 46 (2009) 177–185 ⁎ Corresponding author. Tel.: +31 20 5662749; fax: +31 20 5662609. E-mail addresses: stephan.schirmer@uks.eu, stephanschirmer@gmx.de (S.H. Schirmer). 0022-2828/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.yjmcc.2008.10.029 Contents lists available at ScienceDirect Journal of Molecular and Cellular Cardiology journal homepage: www.elsevier.com/locate/yjmcc