大鼠骨髓间质干细胞诱导分化为心肌样细胞膜电流的研究

目的： 研究大鼠骨髓间质干细胞（MSCs）诱导分化为心肌样细胞膜电流的状态。方法： 按文献方法进行MSCs的诱导培养和鉴定。诱导后培养4周，用全细胞膜片钳技术，检测胞膜电流，并与未经诱导分化的MSCs进行比较。结果： 未经诱导分化的MSCs不表达内向电流，只表达外向钾电流。MSCs经5-aza诱导后表达心肌特异性肌钙蛋白T，记录到2种膜内向电流，分别为钠电流（I_Na）和L-型钙电流（I_Ca），以及3种外向钾电流，包括瞬间外向钾电流（I_to），超快速激活延迟整流钾电流（I_kur）及缓慢激活延迟整流钾电流（I_ks）。与未经诱导分化的MSCs相比，诱导后MSCs的钾电流以I_kur和I_ks为主。结论： 经5-aza诱导后，MSCs可分化成具有电压依赖性内向I_Na、I_Ca和外向I_to、I_kur、I_ks的心肌样细胞。

Electrophysiological characteristics of the membrane current of cardiomyocytes-like cells derived from rat bone marrow mesenchymal stem cells

AIM:To study the electrophysiological characteristics of the membrane currents of cardiomyocytes-like cells derived from rat bone marrow mesenchymal stem cells(MSCs).METHODS:MSCs were induced,cultured and identified according to the reference.At the fourth week after treatment with 5-azacytidine(5-aza),cardiomyocytes-like cells were detected for the membrane current with the whole-cell patch-clamp technique and compared with the undifferentiated MSCs.RESULTS:The undifferentiated MSCs only expressed potassium currents.MSCs were stained positive for troponin T after treatment with 5-aza,and two kinds of inward currents and three kinds of outward currents were expressed.They respectively were the fast inward sodium current(INa),the L-type calcium current(ICa),the transient outward potassium current(Ito),the ultra-rapid delayed rectifier potassium current(Ikur)and the slow delayed rectifier potassium current(Iks).Compared with the undifferentiated MSCs,the potassium currents of cardiomyocytes-like cells derived from MSCs were mainly made up of Ikur and Iks.CONCLUSION:After treatment with 5-azacytidine,MSCs are differentiated into cardiomyocytes-like cells,which express the current of INa,ICa,Ito,Ikur and Iks.