Fijnvandraat Arnoud C, Lekanne Deprez Ronald H, Christoffels Vincent M, Ruijter Jan M, Moorman Antoon F M
Experimental and Molecular Cardiology Group, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
J Muscle Res Cell Motil. 2003;24(2-3):211-8. doi: 10.1023/a:1026063409656.
In vitro differentiation of pluripotent embryonic cells is becoming a model system to study factors and genes involved in early developmental processes including cardiogenesis. An additional application involves the development of donor cells for treatment of diseases among which cardiac infarction. For this purpose differentiated cells should meet the functional characteristics of chamber myocardium, a requirement not convincingly reached as yet. The T-box transcription factor Tbx5 has been demonstrated to be crucial for heart formation. Using stably transfected clones of the P19C16 embryonic carcinoma cell line, reported to differentiate efficiently into the cardiac lineage, we investigated whether Tbx5 is sufficient to enhance cardiogenesis and differentiation of chamber myocardium. TBX5-transfected clones started to beat earlier, however, a relation between transgenic TBX5 mRNA levels and the number of beating foci or levels of Serca2a mRNA, a myocardial marker, could not be observed. However, TBX5-transfected clones displayed significantly higher levels of atrial natriuretic factor (Anf) and Connexin (Cx)40 mRNAs, which are associated with the formation of chamber myocardium. This indicates that Tbx5 enhances cardiac maturation within this system rather than cardiogenesis.
多能胚胎细胞的体外分化正成为一种模型系统，用于研究参与早期发育过程（包括心脏发生）的因子和基因。另一个应用涉及开发用于治疗包括心肌梗死在内的疾病的供体细胞。为此，分化细胞应符合心室心肌的功能特性，而这一要求目前尚未令人信服地实现。T-box转录因子Tbx5已被证明对心脏形成至关重要。利用稳定转染的P19C16胚胎癌细胞系克隆，据报道该细胞系能有效分化为心脏谱系，我们研究了Tbx5是否足以增强心脏发生和心室心肌的分化。转染TBX5的克隆更早开始跳动，然而，未观察到转基因TBX5 mRNA水平与跳动灶数量或心肌标志物Serca2a mRNA水平之间的关系。然而，转染TBX5的克隆显示心房钠尿肽（Anf）和连接蛋白（Cx）40 mRNA水平显著更高，这与心室心肌的形成有关。这表明Tbx5在该系统中增强的是心脏成熟而非心脏发生。
