大鼠肝星状细胞大电导钙激活钾通道特性与细胞增殖的关系

Relationship between characteristics of large conductance calcium-activated potassium channel in hepatic stellate cells and proliferation of hepatic stellate cells in rats

目的探讨肝星状细胞(HSC)钙激活钾通道特性,以及钾通道对HSC增殖的影响。方法以胶原酶循环灌流法分离大鼠HSC,用结蛋白抗体及α-抗平滑肌抗体进行分离细胞鉴定,采用单通道细胞膜片钳技术检测传代HSC钾通道的特性,通过MTT法、流式细胞术分别检测钾离子通道阻滞剂四乙胺(TEA)对HSC的增殖、细胞周期的影响。结果所分离细胞为HSC。传代活化的HSC有单通道存在,其电导值为(210.86±5.49)pS(n=7),属于大电导通道;其通道表现出明显的电压依赖性以及对钙敏感性,TEA可明显减少外向钾离子通道开放概率。TAE对HSC的增殖抑制效应具有时间依赖与剂量依赖的特点,可使细胞周期阻滞于G0/G1期。结论 HSC上大电导钙激活钾通道可能参与了HSC活化增殖。

Objective To explore the charateristics of Ca2＋-activated potassium channels in rat hepatic stellate cells and the effect of the channels on proliferation of rat hepatic stellate cells（HSC）.Methods The rat hepatic stellate cells were isolated with collagenase recirculating perfusion.These cells were identified by immunohistochemistry of desmin and α-SMA antibody.The Ca2＋-activated potassium currents were recorded by patch clamp technique.The effects of TEA（Ca2＋-activated potassium channels blocker） on proliferation and cell cycle of HSC were assessed by MTT and flow cytometry.Results These cells were identified as HSC.Channels currents were detected by patch-clamp in the activated HSC and showed a large conductance of（210.86±5.49）pS（n=7）.The characteristics of open probability of the channel were both voltage and intracellular calcium dependent.TEA significantly decreased the open probability of the channel.TEA inhibited the proliferation of HSC in dose-and time-dependent manners and stopped the celI cycle at G0/G1 phase.Conclusions Large-conductance Ca2＋-actived potassium channels on activated rat HSC might be involved in regulating proliferation of HSC.