大鼠骨髓间充质干细胞培养4周膜电流研究

Electrophysiological property of rat bone marrow mesenchymal stem cells in 4 weeks culture

目的:研究未经诱导SD大鼠骨髓间充质干细胞(MSCs)培养4周(4～6代)膜电流特性,为移植细胞的选取和细胞移植后心肌电生理研究奠定基础。方法:按文献方法获得和培养MSCs至第4周,利用全细胞膜片钳技术对培养4周的MSCs膜电流进行检测,以各种钾钠钙通道阻滞剂对电流成分进行分析鉴定。结果:本实验成功封接并有电流表达细胞共39例,所有检测到的电流均以相应阻滞剂证实。共有4种钾电流表达即缓慢激活延迟整流钾电流、瞬时外向钾电流、超速激活延迟整流钾电流和内向整流钾电流(Ikir),3种外向钾电流在+60mV时电流峰值均值分别为(0.3894±0.1230)nA、(0.4135±0.1029)nA、(0.2570±0.1135)nA;Ikir在-120mV时电流大小为(0.9613±0.1484)nA;此外在极少数MSCs上检测到河豚毒素敏感的内向钠电流(ITTX.Na),未检测到内向钙电流。结论:培养4周后的MSCs存在钾钠电流的复合表达,从电生理角度看,MSCs有分化成功能性心肌样细胞的离子基础,其可作为体内移植较理想细胞选择。

Objective：We study the ion channels of mesenchymal stem cells （MSCs） from Sprague-Dawley rats bone marrow after four weeks culture in vitro,which contributes to cell selection for implantation and investigate electrophysiological property of cadiocyte after implantation. Method： With gradient eentrifugation and monolayer attachment culture method, the MSCs were isolated from rat bone marrow and were cultured for four weeks. The membrane currents were test by whole-cell patch clamp technology. The channel blockers were used to analysis the membrane ion channels. Result：There were thirty-nine cells either having the expression o5 inward currents or outward K＋ currents：a delayed rectifier K＋ current （Iks） ,a transient outward K＋ current （Ito） , a super activa tion delayed rectifier K＋ current （Ikur） and a inward rectifier K＋ current （Ikir）. The current strength of the three types of outward K＋ current at ＋60 mV were （0. 3894±0. lga0）nA, （0. 4135±0. 1029）nA, （0. 2570±0. 1135） nA, the current strength of Ikir at --120 mV was （0. 9613±0. 1484）nA. Furthermore, a tetrodotoxin sensitive sodium current current （ITTx. Na） in only two rat MSCs was found. No inward Ca2＋ current（IL-ca） was detected. Conclusion： There were multiple functional ion channel currents （Iks, Ikir, Ikur, Ito and ITTx. Na ） were presented in the MSCs from rats bone marrow, which demonstrated that the MSCs had the ionic foundation to dif ferentiate into functional cardiomyocytes after cultured for 10ng time in vitro, and it might be an ideal cell resources for cell implantation.