title: High-density lipoprotein exerts vasculoprotection via endothelial progenitor cells.
abstract: Endothelial progenitor cells (EPC) enhance endothelial cell repair, improve endothelial dysfunction and are a predictor for cardiovascular mortality. High-density lipoprotein (HDL) cholesterol levels inversely correlate with cardiovascular events and have vasculoprotective effects. Here we postulate that HDL influences EPC biology. HDL and EPC were isolated according to standard procedures. Differentiation of mononuclear cells into DiLDL/lectin positive cells was enhanced after HDL treatment compared to vehicle. HDL was able to inhibit apoptosis (TUNEL assay, annexin V staining) while proliferation (BrdU incorporation) of early outgrowth colonies after extended cell cultivation (14 days) was increased. Flow chamber experiments revealed an improved adhesion of HDL pre-incubated EPC on human coronary artery endothelial cells (HCAEC) compared to vehicle while HDL treatment of HCAEC prevented adhesion of inflammatory cells. Flow cytometry demonstrated an up-regulation of beta2- and alpha4-integrins on HDL pre-incubated EPC. Blocking experiments revealed a unique role of beta2-integrin in EPC adhesion. Treatment of wild-type mice with recombinant HDL after endothelial denudation resulted in enhanced re-endothelialization compared to vehicle. Finally, in patients with coronary artery disease a correlation between circulating EPC and HDL concentrations was demonstrated. We provide evidence that HDL mediates important vasculoprotective action via the improvement of function of circulating EPC.
authors.affiliation: Department of Internal Medicine II, University Hospital Bonn, Bonn, Germany.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Petoumenos
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.forename: Nikos
authors.initials: N
authors.lastname: Werner
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects* / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects; D008075:Lipoproteins, HDL / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D051379:Mice; D018919:Neovascularization, Physiologic / Q000187:drug effects; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology
chemical_list: D008075:Lipoproteins, HDL; D020011:Protective Agents; D012333:RNA, Messenger; D011994:Recombinant Proteins; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III