title: Optimal time for human umbilical cord blood cell transplantation in rats with myocardial infarction.
abstract: BACKGROUND
  Cell therapy for cardiac regeneration is still under investigation. To date there have been a limited number of studies describing the optimal time for cell injection. The present study aimed to examine the optimal time for human umbilical cord blood cells (HUCBCs) transplantation after myocardial infarction (MI).
  
  
  METHODS
  The animals underwent MI by ligation of the left anterior descending coronary artery and received an intravenous injection of equal volumes of HUCBCs or phosphate buffered saline at days 1, 5, 10 and 30 after MI. HUCBCs were detected by immunostaining against human human leucocyte antigen (HLA). Cardiac function, histological analysis and measurement of vascular endothelial growth factor (VEGF) were performed 4 weeks after cell transplantation.
  
  
  RESULTS
  HUCBCs transplantation could improve cardiac function in rats that received transplantation at 5 and 10 days after MI. The best benefit was achieved in rats that received cells at 10-day after MI. Survival of engrafted HUCBCs, angiogenesis and VEGF expression were more obvious in the 10-day transplantation group than in the other transplantation groups. No evidence of cardiomyocyte regeneration was detected in any transplanted rats.
  
  
  CONCLUSIONS
  HUCBCs transplantation could improve cardiac function in rats that received HUCBCs at days 5 and 10 after MI with the optimal time for transplantation being 10 days post MI. Angiogenesis, but not cardiomyocyte regeneration, played a key role in the cardiac function improvement.
authors.affiliation: Cardiovascular Department, Beijing Friendship Hospital, Capital Medical University, Beijing, China. xingyunli@medmail.com.cn
authors.forename: Yun-li
authors.initials: YL
authors.lastname: Xing
authors.forename: Lu-hua
authors.initials: LH
authors.lastname: Shen
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Li
authors.forename: Yu-chen
authors.initials: YC
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.forename: Shu-mei
authors.initials: SM
authors.lastname: Zhao
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
mesh_terms: D000818:Animals; D036101:Cord Blood Stem Cell Transplantation / Q000379:methods*; D004452:Echocardiography; D006439:Hemodynamics; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors