title: Delayed enrichment for c-kit and inducing cardiac differentiation attenuated protective effects of BMSCs' transplantation in pig model of acute myocardial ischemia.
abstract: OBJECTIVE
  To investigate the effects of immature cardiomyocytes differentiated from c-kit(+) bone marrow mesenchymal stem cells (BMSCs) against acute myocardial infarction (AMI).
  
  
  METHODS
  Miniswine passage 8 BMSCs were enriched for c-kit and induced by 5 μM 5-azacytidine (AZA) for 14 days, and a second enrichment for the dihydropyridine receptor subunit α2δ1 was performed (enriched BMSCs). Thereafter, enriched BMSCs were analyzed by determining cardiac differentiation, secretion function, and the effects of these secreted factors on cardiac stem cells (CSCs). Miniswine with AMI were divided into control, primary BMSCs' (PB), and enriched BMSCs' (EB) groups. Autologous BMSCs were intramyocardially injected into the ischemic regions in PB and EB groups. The following indices were evaluated at different time points, including paracrine of implanted BMSCs, histological and morphological analysis, myocardial perfusion, and cardiac function.
  
  
  RESULTS
  As shown by in vitro study, enrichment + AZA significantly promoted BMSCs to express cardiac-specific markers and format action potential, but down-regulated the expression of VEGF and bFGF, consequently attenuated BMSCs-inducing CSCs proliferation, migration, and differentiation. The in vivo experiments revealed similar results like the in vitro 6 weeks postoperatively. And in EB group, there were decreased angiogenesis and myocardial perfusion, attenuated resident CSCs-mediated myocardial regeneration, and consequently impaired cardiac function compared with PB group.
  
  
  CONCLUSIONS
  This pretreatment promoted BMSCs to differentiate into myocardiocytes both in vitro and in vivo, but impaired their paracrine function and effects on resident CSCs, suggesting that inducing cardiac differentiation alone may not improve protective effects of BMSCs transplantation on AMI.
authors.affiliation: Department of Cardiac Surgery, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Guang-Wei
authors.initials: GW
authors.lastname: Zhang
authors.affiliation: Department of Cardiac Surgery, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Tian-Xiang
authors.initials: TX
authors.lastname: Gu
authors.affiliation: Department of Cardiac Surgery, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Guan
authors.affiliation: Department of Anesthesiology, The First Hospital of China Medical University, Shenyang, China.|Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China.
authors.forename: Xue-Jun
authors.initials: XJ
authors.lastname: Sun
authors.affiliation: Department of Cardiac Surgery, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Da-Qing
authors.initials: DQ
authors.lastname: Jiang
authors.affiliation: Department of Cardiac Surgery, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Tang
authors.affiliation: Department of Radiology, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Qi
authors.affiliation: Department of Cardiology, The First Hospital of China Medical University, Shenyang, China.
authors.forename: Xue-Yuan
authors.initials: XY
authors.lastname: Li
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003326:Coronary Circulation; D004195:Disease Models, Animal; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism*; D009203:Myocardial Infarction / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000637:transplantation*; D018919:Neovascularization, Physiologic; D019899:Paracrine Communication; D010641:Phenotype; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D012038:Regeneration; D013552:Swine; D013556:Swine, Miniature; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D016277:Ventricular Function, Left; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D020746:Calcium Channels, L-Type; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; D016222:Fibroblast Growth Factor 2; D019009:Proto-Oncogene Proteins c-kit; D001374:Azacitidine
keywords: Cell differentiation; myocardial infarction; regeneration; stem cell transplantation; ventricular function