title: Human amniotic mesenchymal cells have some characteristics of cardiomyocytes.
abstract: BACKGROUND
  Cellular cardiomyoplasty (CCM) is a major method for the treatment of heart failure because adult cardiomyocytes do not regenerate after ischemic injury, which results in heart failure. There is a great deal of interest in finding suitable new cell sources for use in CCM. Here, we report that human amniotic mesenchymal cells (hAMC), which are multipotent cells derived from fetal mesoderm, may be a suitable cell source for CCM.
  
  
  METHODS
  Freshly isolated hAMC were examined to detect the expression of cardiac-specific genes by reverse-transcription polymerase chain reaction and immunocytochemistry. hAMC were cocultivated with neonatal rat heart explants and transplanted into myocardial infarcts in the rat heart.
  
  
  RESULTS
  hAMC expressed cardiac-specific transcription factor GATA4, cardiac-specific genes, such as myosin light chain (MLC)-2a, MLC-2v, cTnI, and cTnT, and the alpha-subunits of the cardiac-specific L-type calcium channel (alpha1c) and the transient outward potassium channel (Kv4.3). After stimulation with basic fibroblast growth factor (bFGF) or activin A, hAMC expressed Nkx2.5, a specific transcription factor for the cardiomyocyte and cardiac-specific marker atrial natriuretic peptide. In addition, the cardiac-specific gene alpha-myosin heavy chain was detected after treatment with activin A. Coculture experiments confirmed that hAMC were able to both integrate into cardiac tissues and differentiate into cardiomyocyte-like cells. After transplantation into the myocardial infarcts in rat hearts, hAMC survived in the scar tissue for at least 2 months and differentiated into cardiomyocyte-like cells.
  
  
  CONCLUSIONS
  The results of the present study suggest that hAMC possess some characteristics of cardiomyocytes.
authors.affiliation: Department of Organ Regeneration, Institute of Organ Transplants, Reconstructive Medicine and Tissue Engineering, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Ise
authors.forename: Minoru
authors.initials: M
authors.lastname: Hongo
authors.forename: Masao
authors.initials: M
authors.lastname: Ota
authors.forename: Ikuo
authors.initials: I
authors.lastname: Konishi
authors.forename: Toshio
authors.initials: T
authors.lastname: Nikaido
mesh_terms: D000650:Amnion / Q000166:cytology*; D000818:Animals; D002454:Cell Differentiation; D002470:Cell Survival; D005260:Female; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000032:analysis; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014157:Transcription Factors / Q000032:analysis; D014183:Transplantation, Heterologous
chemical_list: D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C095552:NKX2-5 protein, human; D014157:Transcription Factors