Atherosclerosis 214 (2011) 316–324 Contents lists available at ScienceDirect Atherosclerosis journal homepage: www.elsevier.com/locate/atherosclerosis Antagonistic regulation of macrophage phenotype by M-CSF and GM-CSF: Implication in atherosclerosis Isabelle Brochériou a,b , Seraya Maouche a , Hervé Durand a , Vincent Braunersreuther c , Gilles Le Naour b , Alexei Gratchev d,e , Fabien Koskas a,g , Franc ¸ ois Mach c , Julia Kzhyshkowska d,e , Ewa Ninio a,∗ a INSERM UMRS937, Université Pierre et Marie Curie UPMC-Paris 6, Faculté de Médecine Pierre et Marie Curie, 91 Boulevard de l’Hôpital, 75634 Paris, France b Department of Pathology, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France c Division of Cardiology, Foundation for Medical Research, University Hospital, Geneva, Switzerland d University Medical Centre Mannheim, Ruprecht-Karls University of Heidelberg, Germany e Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, Moscow, Russia g Department of Vascular Surgery, Hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France article info Article history: Received 28 July 2010 Received in revised form 5 November 2010 Accepted 21 November 2010 Available online 27 November 2010 Keywords: Macrophage phenotypic heterogeneity M-CSF GM-CSF Atherosclerosis Microarrays Tissue microarrays abstract Objectives: We characterized the transcriptional profiles of GM-CSF- (GM-MØ) and M-CSF-induced macrophages (M-MØ) and investigated in situ a subset of differentially expressed genes in human and mouse atherosclerotic lesions. Methods and results: Using microarrays we identified a number of genes and biological processes differ- entially regulated in M-MØ vs GM-MØ. By varying in culture the M-CSF/GM-CSF ratio (0–10), a spectrum of macrophage phenotypes was explored by RT-QPCR. M-CSF (10 ng/ml) stimulated expression of several genes, including selenoprotein-1 (SEPP1), stabilin-1 (STAB1) and CD163 molecule-like-1 (CD163L1) which was inhibited by a low dose of GM-CSF (1 ng/ml); M-CSF inhibited the expression of pro-platelet basic protein (PPBP) induced by GM-CSF. Combining Tissue Microarrays/quantitative immunohistochemistry of human aortic lesions with RT-QPCR expression data either from human carotids vs mammary non- atherosclerotic arteries or from the apoE null mice normal and atherosclerotic aortas showed that, STAB1, SEPP1 and CD163L1 (M-CSF-sensitive genes) and PPBP (GM-CSF-sensitive gene) were expressed in both human arterial and apoE null mice atherosclerotic tissues. Conclusion: A balance between M-CSF vs GM-CSF defines macrophage functional polarisation and may contribute to the progression of atherosclerosis. © 2010 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Monocyte-derived macrophages (MØ) are essential cells for the formation of atherosclerotic lesions as they contribute to local arterial wall inflammation and become lipid-laden foam cells. Macrophages are phenotypically diverse and their heterogeneity depends upon local environment and stimuli [1]. GM-CSF and M- CSF produced by various cells in response to injury are the major survival/mitogenic factors for the macrophage lineage with the capacity to activate and induce their differentiation [2–4]. Initially M1 and M2 macrophage phenotypes were described by analogy to Th1 and Th2 lymphocyte subsets; macrophages cultivated with either GM-CSF (denominated GM-MØ) or with M-CSF (M-MØ) were named as proinflammatory M1 and anti-inflammatory M2 phenotypes respectively [5,6]. Subsequently a class of “classically ∗ Corresponding author. Tel.: +33 1 40779768, fax: +33 1 40779728. E-mail address: ewa.ninio@upmc.fr (E. Ninio). activated” macrophages was described, i.e. macrophages activated by interferon-gamma (IFNgamma) alone or in concert with either lipopolysaccharide (LPS) or tumor necrosis factor (TNFalpha) and also called M1 macrophages. Finally, the “alternatively activated” macrophages were obtained upon incubation with IL-4 or IL- 10 and called M2 macrophages [7,8]. Classically activated M1 macrophages express several pro-inflammatory cytokines, such as IL-1, TNFalpha and IL-6, while their M2 counterparts are considered as anti-inflammatory as they generate IL-10 and TGFbeta. In human plasma [9] and in swine arterial wall [10] the concen- trations of M-CSF are increased in the presence of coronary artery disease and those of GM-CSF are increased in aortic sinus lesions of apoE null atherosclerotic mice [11]; moreover GM-CSF mRNA is expressed in human vascular cells, including endothelial, smooth muscle cells and macrophages, as showed by in situ hybridization [12]. Recently, GM-CSF was proposed as a key regulator of inti- mal cell proliferation in mouse lesions [13]. Therefore the relative ratio between GM-CSF and M-CSF in situ may lead to “priming” and to “activation” of monocytes/macrophages and their phenotypic 0021-9150/$ – see front matter © 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.atherosclerosis.2010.11.023