Isolation, culture and characterization of cardiac progenitor cells derived from human embryonic heart tubes.
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.
Zhang
Xi
X
Institute of Biomedical Engineering, Second Military Medical University, Shanghai 200433, China.
Zhang
Chuan-Sen
CS
Liu
Yan-Chun
YC
Yang
Xiang-Qun
XQ
Xiong
Shao-Hu
SH
Wen
Yu
Y
Jiang
Er-Peng
EP
Li
Rui
R
Zhang
Zhi-Ying
ZY
Liu
Fang
F
Ye
Yong
Y
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
D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C095552:NKX2-5 protein, human; D014157:Transcription Factors