title: Interferon-alpha promotes abnormal vasculogenesis in lupus: a potential pathway for premature atherosclerosis.
abstract: Individuals with systemic lupus erythematosus (SLE) have a striking increase in premature atherosclerosis of unclear etiology. Accelerated endothelial cell apoptosis occurs in SLE and correlates with endothelial dysfunction. Endothelial progenitor cells (EPCs) and myelomonocytic circulating angiogenic cells (CACs) are crucial in blood vessel repair after vascular damage, and decreased levels or abnormal function of EPCs/CACs are established atherosclerosis risk factors. We investigated if vascular repair is impaired in SLE. We report that SLE patients display abnormal phenotype and function of EPCs/CACs. These abnormalities are characterized by significant decreases in the number of circulating EPCs (310 +/- 50 EPCs/mL of blood in SLE versus 639 +/- 102 in controls) and significant impairments in the capacity of EPCs/CACs to differentiate into mature ECs and synthesize adequate levels of the proangiogenic molecules vascular endothelial growth factor (VEGF) and hepatic growth factor (HGF). These abnormalities are triggered by interferon-alpha (IFN-alpha), which induces EPC and CAC apoptosis and skews myeloid cells toward nonangiogenic phenotypes. Lupus EPCs/CACs have increased IFN-alpha expression and their supernatants promote higher induction of IFN-inducible genes. Importantly, neutralization of IFN pathways restores a normal EPC/CAC phenotype in lupus. SLE is characterized by an imbalance between endothelial cell damage and repair triggered by type I IFNs, which might promote accelerated atherosclerosis.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Denny
authors.forename: Seth
authors.initials: S
authors.lastname: Thacker
authors.forename: Hemal
authors.initials: H
authors.lastname: Mehta
authors.forename: Emily C
authors.initials: EC
authors.lastname: Somers
authors.forename: Todd
authors.initials: T
authors.lastname: Dodick
authors.forename: Franck J
authors.initials: FJ
authors.lastname: Barrat
authors.forename: W Joseph
authors.initials: WJ
authors.lastname: McCune
authors.forename: Mariana J
authors.initials: MJ
authors.lastname: Kaplan
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000502:physiology; D050197:Atherosclerosis / Q000209:etiology*; D002454:Cell Differentiation / Q000502:physiology; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D006801:Humans; D016898:Interferon-alpha / Q000378:metabolism*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D016898:Interferon-alpha; D012333:RNA, Messenger