Human cardiomyocyte progenitor cell-derived cardiomyocytes display a maturated electrical phenotype

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• 作者：Teun P. de Boer ; Toon A.B. van Veen ; Malin K.B. Jonsson ; Bart G.J.M. Kok ; Corina H.G. Metz ; Joost P.G. Sluijter ; Pieter A. Doevendans ; Jacques M.T. de Bakker ; Marie-José ; Goumans ; Marcel A.G. van
• 关键词：Ion channels/membrane transporters ; Stem cells ; Electrophysiology ; Myogenesis ; Cardiac development
• 刊名：Journal of Molecular and Cellular Cardiology
• 出版年：2010
• 出版时间：January 2010
• 年：2010
• 卷：48
• 期：1
• 页码：254-260
• 全文大小：787 K

文摘

Cardiomyocyte progenitor cells (CMPCs) can be isolated from the human heart and differentiated into cardiomyocytes in vitro. A comprehensive assessment of their electrical phenotype upon differentiation is essential to predict potential future applications of this cell source. CMPCs isolated from human fetal heart were differentiated in vitro and examined using immunohistochemistry, Western blotting, RT-PCR, voltage clamp and current clamp techniques. Differentiated cultures presented up to 95 % α-actinin positive cardiomyocytes. Adherens junction and desmosomal proteins β-catenin, N-cadherin, desmin and plakophilin2 were upregulated. Expression levels of cardiac connexins were not affected by differentiation, however Cx43 phosphorylation was increased upon differentiation, accompanied by translocation of connexins to the cell border. RT-PCR analysis demonstrated upregulation of all major cardiac ion channel constituents during differentiation. Patch clamp experiments showed that cardiomyocytes had a stable resting membrane potential of − 73.4 ± 1.8 mV. Infusion of 1 mM BaCl₂ resulted in depolarization to − 59.9 ± 2.8 mV, indicating I_K1 channel activity. Subsequent voltage clamp experiments confirmed presence of near mature I_Na, I_Ca,L and I_K1 current densities. Infusion of the I_Kr blocker Almokalant caused prolongation of the action potential by 40 % . Differentiated monolayers were not spontaneously contracting in the absence of serum, but responded to field stimulation, displaying adult ventricular-like action potentials. Human fetal CMPC-derived cardiomyocytes have a homogenous and rather mature electrical phenotype that benefits to in vitro physiology and pharmacology. In the context of cardiac repair, their properties may translate into a reduced pro-arrhythmic risk and enhanced electrical integration upon transplantation.