title: Effects of magnetically labeled exogenous endothelial progenitor cells on cerebral blood perfusion and microvasculature alterations after traumatic brain injury in rat model.
abstract: BACKGROUND
  Increasing evidence suggests that endothelial progenitor cells (EPCs), a subgroup of bone marrow hematopoietic stromal cells, play a critical role in neovascularization and tissue repair.
  
  
  OBJECTIVE
  To explore the effect of exogenous EPCs on the cerebral blood perfusion and microvessels in the injured region in rat model with traumatic brain injury (TBI).
  
  
  METHODS
  EPCs were collected from the spleens of healthy Sprague-Dawley rats. Fifty-four Sprague-Dawley rats were randomly divided into six groups. The controlled cortical impact TBI was performed. Spleen-derived exogenous EPCs labeled with super-paramagnetic iron oxide (SPIO) (SPIO-EPCs) were transplanted into the blood by tail vein of rats at 6 and 12 h after TBI, respectively. Magnetic resonance imaging (MRI) and computed tomography perfusion imaging were performed at various time points. Microvascular density was determined by immunohistochemistry.
  
  
  RESULTS
  In SPIO-EPCs group, patchlike hypointensities were detected in the injured region at 24 h after transplantation, and the range of hypointensities tended to expand gradually over time on MRI, which was confirmed by Prussian blue staining. Computed tomography perfusion imaging parameters were gradually developed from hyperperfusion to normal, while, microvascular density was gradually increased during 72 to 168 h after injury. The values of these indices in SPIO-EPCs group were significantly lower than those in SPIO-alone group at the same time point, but no significant differences were found in different time groups.
  
  
  CONCLUSIONS
  The intravenously transplanted EPCs diminish the brain injury through restoring cerebral blood perfusion and increasing the cerebral microvasculature in the injured region in rat model with TBI.
authors.affiliation: Department of Radiology, Burns and Combined Injury, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Wu
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.forename: Jingqin
authors.initials: J
authors.lastname: Fang
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Weiguo
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001930:Brain Injuries / Q000628:therapy*; D003287:Contrast Media / Q000494:pharmacology*; D003911:Dextrans / Q000494:pharmacology*; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000166:cytology*; D006439:Hemodynamics; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D008297:Male; D055806:Microvessels; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000166:cytology; D013194:Staining and Labeling; D033581:Stem Cell Transplantation / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides