title: Pretreatment of rat bone marrow mesenchymal stem cells with a combination of hypergravity and 5-azacytidine enhances therapeutic efficacy for myocardial infarction.
abstract: OBJECTIVE
  The in vivo cardiac differentiation and functional effects of unmodified adult bone marrow mesenchymal stem cells (BMSCs) after myocardial infarction (MI) is controversial. Our previous results suggested that hypergravity promoted the cardiomyogenic differentiation of BMSCs, and thus we postulated that ex vivo pretreatment of BMSCs using hypergravity and 5-azacytidine (5-Aza) would lead to cardiomyogenic differentiation and result in superior biological and functional effects on cardiac regeneration of infarcted myocardium.
  
  
  METHODS
  We used a rat MI model generated by ligation of the coronary artery. Homogeneous rat BMSCs were isolated, culture expanded, and differentiated into a cardiac lineage by adding hypergravity (2G) for 3 days and 5-Aza (50 lmol/L, 24 h). Rats underwent BMSCs (labeled with DAPI) injection after the infarction and were randomized into five groups. Group A rats received the control medium, Group B rats received unmodified BMSCs, Group C rats received BMSCs treated with hypergravity, Group D rats received BMSCs treated with 5-Aza, and Group E rats received BMSCs treated with 5-Aza and hypergravity (n = 6).
  
  
  RESULTS
  After hypergravity and 5-Aza treatment, BMSCs showed positive for the early muscle and cardiac markers GATA-4, MEF-2, and Nkx2-5 with RT-PCR. We also found that hypergravity could enhance the activities of MEF-2 via promoting the nuclear export of HDAC5. The frozen section showed that the implanted BMSCs labeled with DAPI survived and angiogenesis was identified at the implantation site. In Groups B, C, D, and E rats, pre-treated BMSCs colocalized with α-actinin, and Group E rats showed a significantly larger increase in left ventricular function.
  
  
  CONCLUSIONS
  The biological ex vivo cardiomyogenic differentiation of adult BMSCs with hypergravity and 5-Aza prior to their transplantation is feasible and appears to improve their in vivo cardiac differentiation as well as the functional recovery in a rat model of the infarcted myocardium.
authors.affiliation: Department of Life Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Shu-Kuan
authors.initials: SK
authors.lastname: Ling
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Zhong-Quan
authors.initials: ZQ
authors.lastname: Dai
authors.forename: Jie-Lin
authors.initials: JL
authors.lastname: Nie
authors.forename: Hong-Hui
authors.initials: HH
authors.lastname: Wang
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Tan
authors.forename: Hong-Qing
authors.initials: HQ
authors.lastname: Cao
authors.forename: Zeng-Ming
authors.initials: ZM
authors.lastname: Huang
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Wan
authors.forename: Ying-Hui
authors.initials: YH
authors.lastname: Li
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000494:pharmacology / Q000627:therapeutic use*; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation / Q000187:drug effects; D018471:Hypergravity; D059630:Mesenchymal Stem Cells / Q000187:drug effects*; D009203:Myocardial Infarction / Q000628:therapy*; D032383:Myocytes, Cardiac; D051381:Rats; D012038:Regeneration; D016896:Treatment Outcome
chemical_list: D001374:Azacitidine