大鼠骨髓间充质干细胞培养一周后的细胞膜电流

The membrane currents of the rat bone marrow mesenchymal stem cells after being cultured for one week.

目的通过研究大鼠骨髓间充质干细胞(MSCs)膜电流的状态,以探讨MSCs的电生理学特性。方法取健康SD大鼠的骨髓,经密度梯度离心和贴壁培养获得MSCs,培养1周后,利用膜片钳技术,以全细胞记录模式记录细胞膜电流。利用各种通道阻滞剂对记录到的电流进行鉴定、分析。结果培养1周后的MSCs未记录到内向膜电流,但显示有3种不同的外向电流在MSCs上单独或混合存在。利用氯通道阻滞剂D IDS不能阻断其外向电流,而在电极内液和细胞外液中使用钾通道阻滞剂后发现其膜电流幅度明显减小,提示所记录到的电流为钾电流,分别为:瞬间外向钾电流、超快速激活延迟整流钾电流及缓慢激活延迟整流钾电流。3种钾电流的电流-电压曲线与文献报道的相应钾电流相符。结论培养1周后的MSCs只表达外向钾电流,不同MSCs表达的钾电流差异较大,从电生理学角度提示MSCs具有多向分化潜能。

Objective To study the membrane currents of the rat bone marrow mesenchymal stem cells （MSCs） . Methods Extract bone marrow specimens and isolate MSCs by gradient centrifugation and the character of adhere to culture plates. MSCs were cultured in vitro. After 1 week, these cells were recorded membrane currents with the whole-cell patch-clamp technique. The currents were identified and analyzed by using various channel blockers. Results The inward currents could not be recorded , but at least three kinds of outward currents were detected. The outward currents were existed alone or coexisted on the membrane, and were not sensitive to the chloride channel blocker. By using various potassium channel blocker in the internal or external solutions, we discovered that all of the outward currents diminished obviously. It was confirmed that all of the outward currents were carried by K ^＋ . These three kinds of outward currents respectively were the transient outward current （Ito）, the ultra-rapid delayed rectifier current （IKur ） and the slow delayed rectifier current （IKs）. The I-V curves of the three kinds of K ^＋ currents were consistent with the references. Conclusions After being cultured for 1 week, MSCs only express potassium currents, and different MSCs express various potassium currents. It could be implied from the electrophysiology that the MSCs have potential of multi-directional differentiation.