Expression data from human lupus EPCs/CACs

Systemic lupus erythematosus (SLE) is characterized by increased vascular risk due to premature atherosclerosis independent of traditional risk factors. We previously proposed that interferon-α plays a crucial role in premature vascular damage in SLE. IFN-α alters the balance between endothelial cell apoptosis and vascular repair mediated by endothelial progenitor cells (EPCs) and myeloid circulating angiogenic cells (CACs). Here we demonstrate that IFN-α promotes an antiangiogenic signature in SLE and control EPCs/CACs, characterized by transcriptional repression of IL-1α and β, IL-1 receptor 1 and vascular endothelial growth factor A (VEGF-A) and upregulation of IL-1 receptor antagonist (IL-1RN) and the decoy receptor IL1-R2. IL-1β promotes significant improvement in the functional capacity of lupus EPCs/CACs, therefore abrogating the deleterious effects of IFN-α. We used microarrays to analyze the effect of IFNα on peripheral blood EPCs/CACs and on bone marrow EPCs exposed to proangiogenic stimulation. Human lupus EPCs and CACs from PBMCs were isolated and cultured under proangiogenic stimulation; after IFNa incubation or not, RNA was extracted and processed for hybridization on Affymetrix microarrays.