title: Bone marrow cells contribute to neointimal formation after stent implantation in swine.
abstract: BACKGROUND
  Recent studies suggest that neointimal cells in atherosclerotic lesions are partly derived from bone marrow (BM) cells. However, studies with large animal models have not yet clarified how BM cells contribute to neointimal formation in restenotic lesions. We examined the expression of CD34, a hematopoietic stem cell marker, in the neointima after coronary stent implantation in porcine.
  
  
  METHODS
  Pigs underwent balloon injury in the coronary arteries followed by stent implantation. The arteries were harvested at 3, 7, and 28 days after the stenting. The samples were used for immunohistochemistry for CD34, smooth muscle embryo (SMemb), alpha-smooth muscle cell actin (alpha-SMA), macrophage, c-kit, and AC133 antibodies. In morphometric analysis, each layer of vascular wall was calculated in the sections.
  
  
  RESULTS
  At 3 days, the expressions of CD34 and SMemb were minimal, and many macrophages were seen around the stent struts. At 7 days, co-expression of CD34 and SMemb was observed around the struts, and 11.5% of the neointimal cells were stained by CD34. In addition, c-kit positive cells and AC133 positive cells are detected in neointimal area. At 28 days, the neointima had thickened and expressed alpha-SMA rather than SMemb, and a few CD34-positive cells were detected. In morphometric analysis, luminal area/total vascular area was significantly smaller and intimal area/total vascular area was significantly bigger in 7 and 28 days than in the day of implantation.
  
  
  CONCLUSIONS
  BM cells of possibly hematopoietic origin partially contributed to neointimal formation after coronary stent implantation in a large animal model.
authors.affiliation: Third Department of Internal Medicine, Showa University School of Medicine, Hatanodai, Shinagawa-ku, Tokyo, Japan.
authors.forename: Teruko
authors.initials: T
authors.lastname: Soda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Iso
authors.forename: Taro
authors.initials: T
authors.lastname: Kusuyama
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Omori
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Shoji
authors.forename: Shinji
authors.initials: S
authors.lastname: Koba
authors.forename: Eiichi
authors.initials: E
authors.lastname: Geshi
authors.forename: Takashi
authors.initials: T
authors.lastname: Katagiri
mesh_terms: D000071916:AC133 Antigen; D000199:Actins / Q000276:immunology / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015703:Antigens, CD / Q000276:immunology; D018952:Antigens, CD34 / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000502:physiology*; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006023:Glycoproteins / Q000276:immunology; D007150:Immunohistochemistry; D008264:Macrophages / Q000473:pathology; D008297:Male; D023421:Models, Animal; D018995:Myosin Heavy Chains / Q000276:immunology / Q000378:metabolism; D024501:Nonmuscle Myosin Type IIB / Q000276:immunology / Q000378:metabolism; D010455:Peptides / Q000276:immunology; D015607:Stents; D013552:Swine; D013997:Time Factors; D017539:Tunica Intima / Q000473:pathology*
chemical_list: D000071916:AC133 Antigen; D000199:Actins; D000906:Antibodies; D015703:Antigens, CD; D018952:Antigens, CD34; D015415:Biomarkers; D006023:Glycoproteins; D010455:Peptides; D024501:Nonmuscle Myosin Type IIB; C103815:nonmuscle myosin type IIB heavy chain; D018995:Myosin Heavy Chains