title: Increased expression of granulocyte colony-stimulating factor mediates mesenchymal stem cells recruitment after vascular injury.
abstract: BACKGROUND
  Recent studies indicate that bone marrow-derived cells may significantly contribute to atherosclerosis, post-angioplasty restenosis and transplantation-associated vasculopathy. The responsible bone marrow (BM) cells and mechanisms regulating the mobilization of these cells are currently unclear. The purpose of this study was to investigate the expression of granulocyte colony-stimulating factor (G-CSF) on injured arteries and its effects on mesenchymal stem cells (MSCs) differentiation into vascular smooth muscle cells (VSMCs) in the process of vascular remodeling.
  
  
  METHODS
  Balloon-mediated vascular injury was established in female rats (n = 100) which received radioprotective whole female BM cells by tail vein injection and male MSCs through a tibial BM injection after lethal irradiation. The injured and contralateral carotid arteries were harvested at 3, 7, 14 and 28 days after treatment.
  
  
  RESULTS
  Morphometric analysis indicated that intima to media area-ratio (I/M ratio) significantly increased at 28 days, 0.899 ± 0.057 (P < 0.01), compared with uninjured arteries. Combining fluorescence in situ hybridization (FISH) and immunohistochemical analysis showed that a significant number of the neointimal cells derived from MSCs, (45.2 ± 8.5)% at 28 days (P = 0.01), compared with (23.5 ± 6.3)% at 14 days. G-CSF was induced in carotid arteries subject to balloon angioplasty (fold mRNA change = 8.67 ± 0.63 at three days, relative G-CSF protein = 0.657 ± 0.011 at three days, P < 0.01, respectively, compared with uninjured arteries). G-CSF was chemotactic for MSCs but did not affect the differentiation of MSCs into smooth-muscle-like cells.
  
  
  CONCLUSIONS
  Increased expression of G-CSF by injured arteries plays an essential role in contribution to recruitment and homing of MSCs to the site of the arterial lesion.
authors.affiliation: Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Ying-Xi
authors.initials: YX
authors.lastname: Liu
authors.forename: Shuang-Lun
authors.initials: SL
authors.lastname: Xie
authors.forename: Bing-Qing
authors.initials: BQ
authors.lastname: Deng
authors.forename: Jing-Feng
authors.initials: JF
authors.lastname: Wang
authors.forename: Ru-Qiong
authors.initials: RQ
authors.lastname: Nie
mesh_terms: D000800:Angioplasty, Balloon; D000818:Animals; D015153:Blotting, Western; D002339:Carotid Arteries / Q000601:surgery; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000378:metabolism*; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology; D058426:Neointima / Q000601:surgery / Q000628:therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D057772:Vascular System Injuries / Q000601:surgery* / Q000628:therapy*
chemical_list: D016179:Granulocyte Colony-Stimulating Factor