Characterization and regulation of T-type Ca2+ channels in embryonic stem cell-derived cardiomyocytes.
Characterization and regulation of T-type Ca2+ channels in embryonic stem cell-derived cardiomyocytes.
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胚胎干细胞来源的心肌细胞中 T 型 Ca2 通道的表征和调节。
DOI：
10.1152/ajpheart.01114.2002
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
DudleyJr,SamuelC
中科院分区：
文献类型：
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作者：
Zhang,YingMing;Shang,Lijuan;Hartzell,Criss;Narlow,Michael;Cribbs,Leanne;DudleyJr,SamuelC
t型Ca2+通道可能在心脏发育中起作用。我们研究了来自小鼠胚胎干细胞（ESCs）的心肌细胞（CMs）中T型电流（ICa，T）的发育调控。采用全细胞膜片钳法在离体CMs中研究ICa， t。随后，通过肌球蛋白轻链2v驱动的绿色荧光蛋白表达对CMs进行鉴定，并采用激光捕获显微解剖技术从不同发育时间点的细胞组中分离总RNA。ICa， t表现出Cav3.1的特征，如抵抗Ni2+阻滞，在发育过程中瞬态增加，与自发电活动的测量相关。Real-time RT-PCR结果显示，Cav3.1 mRNA丰度与ica，T。mRNA拷贝数在7+4 d时较低（2拷贝/细胞），在7+10 d时显著增加（27拷贝/细胞，P< 0.01），在7+16 d时达到峰值（174拷贝/细胞），在7+27 d时显著下降（25拷贝/细胞）。这些数据表明，atica在mRNA丰度水平上受到发育调节，并且这种调节与起搏器活动的测量相似，这表明atica可能在CM发育过程中的自发收缩中发挥作用。
T-type Ca2+channels may play a role in cardiac development. We studied the developmental regulation of the T-type currents (ICa,T) in cardiomyocytes (CMs) derived from mouse embryonic stem cells (ESCs).ICa,Twas studied in isolated CMs by whole cell patch clamp. Subsequently, CMs were identified by the myosin light chain 2v-driven green fluorescent protein expression, and laser capture microdissection was used to isolate total RNA from groups of cells at various developmental time points.ICa,Tshowed characteristics of Cav3.1, such as resistance to Ni2+block, and a transient increase during development, correlating with measures of spontaneous electrical activity. Real-time RT-PCR showed that Cav3.1 mRNA abundance correlated (r2= 0.81) withICa,T. The mRNA copy number was low at 7+4 days (2 copies/cell), increased significantly by 7+10 days (27/cell;P< 0.01), peaked at 7+16 days (174/cell), and declined significantly at 7+27 days (25/cell). These data suggest thatICa,Tis developmentally regulated at the level of mRNA abundance and that this regulation parallels measures of pacemaker activity, suggesting thatICa,Tmight play a role in the spontaneous contractions during CM development.