title: Isolation, culture and characterization of cardiac progenitor cells derived from human embryonic heart tubes.
abstract: A variety of studies have reported on the isolation and expansion of cardiac stem cells from adult hearts. However, there is little information concerning cardiac stem/progenitor cells derived from embryonic hearts/heart tubes. To provide more evidence for embryonic heart-derived stem/progenitor cells, Nkx2.5+ human cardiac progenitorcells (hCPCs) were isolated and cloned from human heart tubes. The cells stained positive for Nkx2.5 and Oct-4, and negative for alpha-smooth muscle actin (alpha-SMA), cytokeratin, factor-VIII, alpha-sarcomeric actin and c-Kit. GATA-4 expression of Nkx2.5+ hCPCs was higher than that of embryonic limb bud mesenchymal cells of the control group (p < 0.05). These cells were passaged continuously for >3 months (23 passages) and proliferated actively in vitro. After being treated with 5-azacytidine, Nkx2.5+ hCPCs underwent cardiomyogenic differentiation. Ultrastructural observation confirmed that the longitudinal section of these cardiomyogenic differentiation cells clearly revealed typical sarcomeres and intercalated discs. alpha-MHC, alpha-sarcomeric actin and GATA-4 levels were increased in Nkx2.5+ hCPCs treated with 5-azacytidine compared to untreated cells. Nkx2.5+ hCPCs exhibited positive staining and had a higher expression for alpha-SMA when cocultured with canine vascular endothelial cells. After Nkx2.5+ hCPCs were treated with endothelin-1, all cells displayed spontaneous electrical activity and spontaneous beating. Connexin-40 and -45 were stained positive in the treated cells. In conclusion, Nkx2.5+ hCPCs derived from heart tubes have been isolated and cloned in vitro. These cells are capable of long-term self-renewal and possess a potential to differentiate into cardiac muscle-like cells, cardiac pacemaking cells and smooth muscle-like cells. They could have a significant impact on cardiac regeneration medicine and developmental biology.
authors.affiliation: Institute of Biomedical Engineering, Second Military Medical University, Shanghai 200433, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.forename: Chuan-Sen
authors.initials: CS
authors.lastname: Zhang
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Liu
authors.forename: Xiang-Qun
authors.initials: XQ
authors.lastname: Yang
authors.forename: Shao-Hu
authors.initials: SH
authors.lastname: Xiong
authors.forename: Yu
authors.initials: Y
authors.lastname: Wen
authors.forename: Er-Peng
authors.initials: EP
authors.lastname: Jiang
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.forename: Zhi-Ying
authors.initials: ZY
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Ye
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D002469:Cell Separation; D002478:Cells, Cultured; D004285:Dogs; D006321:Heart / Q000196:embryology*; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000032:analysis; D006801:Humans; D032383:Myocytes, Cardiac / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology*; D014157:Transcription Factors / Q000032:analysis
chemical_list: D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C095552:NKX2-5 protein, human; D014157:Transcription Factors