title: CCR5 facilitates endothelial progenitor cell recruitment and promotes the stabilization of atherosclerotic plaques in ApoE-/- mice.
abstract: BACKGROUND
  Unstable atherosclerotic plaques are prone to rupture, which leads to atherothrombosis. Endothelial progenitor cells (EPCs) are bone marrow-derived precursor cells that may repair vascular injury in atherosclerosis. Chemokine (C-C motif) receptor 5 (CCR5) promotes mobilization of EPCs. In this study, we investigated the therapeutic potential of CCR5-overexpressing EPCs on plaque stabilization in an apolipoprotein E (ApoE)-/- mouse model.
  
  
  METHODS
  The expression of CCR5 and its cognate ligand chemokine (C-C motif) ligand 5 (CCL5) was examined in atherosclerotic aortas of humans and mice by immunohistochemistry. Splenectomized ApoE-/- C57BL/6 J mice fed a high-fat diet for 24 weeks were intravenously injected with EPCs transfected with CCR5 overexpression lentivirus. The recruitment of EPCs over the atherosclerotic plaques was evaluated by immunofluorescence. The content of lipid, smooth muscle cells, monocytes/macrophages, and endothelial cells in atherosclerotic plaques was assayed by specific immunostaining. The serum levels of atherosclerosis-related inflammatory factors in ApoE-/- mice were measured by mouse atherosclerosis antibody array I.
  
  
  RESULTS
  CCR5 and CCL5 are highly expressed in atherosclerotic plaques in both humans and mice. The ApoE-/- mice with CCR5-overexpressing EPC treatment demonstrated a more stable plaque formation with enhanced recruitment of EPC, reduced lipid, and macrophage content in the atherosclerotic plaques. CCR5-overexpressing EPC treatment also increased the content of endothelial cells and nitric oxide production in the plaques. In addition, the serum levels of interleukin-3 (IL-3), IL-5, IL-6, IL-13, CD40, and tumor necrosis factor-alpha and the plaque contents of IL-6 and matrix metalloproteinase-9 were reduced in mice with CCR5-overexpressing EPC treatment.
  
  
  CONCLUSIONS
  These findings suggest that CCR5 is a novel therapeutic target in EPC treatment for stabilization of atherosclerotic plaques.
authors.affiliation: Department of Medicine, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong, 250014, China. zhangzhongwen521@126.com.
authors.forename: Zhongwen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Medicine, Qilu Hospital of Shandong University, Wenhua Road, Jinan, 250012, China. dongjianjun@medmail.com.cn.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Miami Mice Research Corp., 101 College Street, Toronto, Ontario, M5G 1 L7, Canada. corrinnelobe@gmail.com.
authors.forename: Corrinne G
authors.initials: CG
authors.lastname: Lobe
authors.affiliation: Department of Medicine, Qilu Hospital of Shandong University, Wenhua Road, Jinan, 250012, China. gongpeiyunshanda@163.com.
authors.forename: Peiyun
authors.initials: P
authors.lastname: Gong
authors.affiliation: Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong, 250014, China. ju.liu@sdu.edu.cn.
authors.forename: Ju
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Medicine, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong, 250014, China. liaolin@medmail.com.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Liao
mesh_terms: D000818:Animals; D001011:Aorta / Q000473:pathology; D001057:Apolipoproteins E / Q000235:genetics; D050197:Atherosclerosis; D019013:CD40 Antigens / Q000097:blood; D002465:Cell Movement; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000096:biosynthesis*; D004195:Disease Models, Animal; D066026:Endothelial Progenitor Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D018793:Interleukin-13 / Q000097:blood; D007377:Interleukin-3 / Q000097:blood; D015848:Interleukin-5 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D019713:Receptors, CCR5 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D001057:Apolipoproteins E; C000592874:CCR5 protein, mouse; D019013:CD40 Antigens; C503460:Ccl5 protein, mouse; D018946:Chemokine CCL5; D018793:Interleukin-13; D007377:Interleukin-3; D015848:Interleukin-5; D015850:Interleukin-6; D019713:Receptors, CCR5; D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9