title: The mechanism underlying the differentiation of human umbilical cord-derived mesenchymal stem cells into myocardial cells induced by 5-azacytidine.
abstract: OBJECTIVE
  To investigate the molecular mechanism underlying the differentiation of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) into myocardial cells induced by 5-azacytidine (5-aza), and to explore the expression and significance of DLL4-Notch signaling in this process.
  
  
  METHODS
  hUCMSCs were isolated and purified from the umbilical cords of normal or cesarean term deliveries under sterile conditions. After treatment with 5-aza for 24 h, hUCMSCs was continued to culture, the expression of GATA4 and NKx2.5 at 4 weeks after induction, DLL4 and Notch1 mRNA at 1d, 3d, 5d, 7d after induction were detected. The expression of cardiac troponin I (cTnI) after 4 weeks was determined by immunocytochemistry.
  
  
  RESULTS
  hUCMSCs treated with 5-aza were stained positively for cTnI 4 weeks after induction. The expression of Notch1 and DLL4 mRNA in the 5-aza-induced group was stable and significantly higher than that in the control group (mean Ct value for the Notch1 gene: 0.51 ± 0.21 in the 5-aza-induced group vs. 7.85 ± 0.35 in the control group; mean Ct value for the DLL4 gene: 1.60 ± 0.49 in the 5-aza-induced group vs. 12.42 ± 0.73 in the control group). Similar results were observed for Nkx2.5 and GATA4 genes. The expressions of Nkx2.5 and GATA4 mRNA in the 5-aza group were 4.72 ± 0.58 and 3.76 ± 0.06 times higher than that in the control group, respectively, with statistical significance.
  
  
  CONCLUSIONS
  hUCMSCs can be differentiated into myocardial cells by 5-aza induction in vitro. 5-Aza may affect this process by regulating the expression of GATA4 and Nkx2.5 genes. The DLL4-Notch signal pathway may be involved in this process.
authors.affiliation: Department of Cardiology, Taizhou People's Hospital, Taizhou-225300, P.R. China. ruanzhongbao@medmail.com.cn
authors.forename: Zhong-Bao
authors.initials: ZB
authors.lastname: Ruan
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Yi-Gang
authors.initials: YG
authors.lastname: Yin
authors.forename: Ge-Cai
authors.initials: GC
authors.lastname: Chen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D001374:Azacitidine / Q000494:pharmacology*; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology; D050991:GATA4 Transcription Factor / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051881:Receptor, Notch1 / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics; D019210:Troponin I / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; D050991:GATA4 Transcription Factor; C484170:GATA4 protein, human; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; C095552:NKX2-5 protein, human; C497761:NOTCH1 protein, human; D012333:RNA, Messenger; D051881:Receptor, Notch1; D014157:Transcription Factors; D019210:Troponin I; D001374:Azacitidine