中文摘要：

本文旨在研究大蒜素（allitridum,All）对SCN5A-F1473S突变的HEK293细胞钠电流降低的逆转作用,为筛选治疗Brugada综合征的新药提供理论依据。采用瞬时转染的方法,将SCN5A-F1473S通道质粒转入HEK293细胞,采用细胞外灌流和共培养模式的方法将All急性和慢性给药,使其作用浓度为30μmol·L^-1。采用全细胞膜片钳技术在电压钳模式下记录电流和门控动力学,采用共聚焦显微镜技术和蛋白质免疫印迹技术检测通道蛋白在细胞膜表达,探讨All对SCN5A-F1473S峰钠电流降低的逆转作用。发现All 30μmol·L^-1组的HEK293细胞峰钠电流（269.8±16.6 p A/p F）显著增加（P〈0.01）,几乎接近对照组电流密度（298.2±17.5 p A/p F,P〈0.01）。All可使通道稳态失活向更正的方向移动（V1/2,inact恢复至-79.5±2.4 m V,P〈0.01）,导致失活减慢,并且使通道中间态失活减缓（延长至598.1±22.6 ms,P〈0.01）。同时,All增加通道蛋白在细胞膜的分布和表达（与F1473S相比,P〈0.01）。All使SCN5A-F1473S突变的细胞电流增加,其主要机制可能与此药物能减慢通道失活及改善突变通道迁移障碍有关。

英文摘要：

This study was designed to test the allitridum（All） activity in correction of sodium current decrease caused by SCN5A-F1473 S mutation in HEK293 cells. The result may provide a theoretical basis for screening of new drugs in the treatment of Brugada syndrome. We transferred SCN5A-F1473 S channel plasmids into HEK293 cells in a transient transfection. All was administrated acutely and chronically using extracellular irrigation flow and co-culture model. The concentration of All was 30 μmol·L^-1. We used whole cell patch clamp technique in voltage clamp mode to record current and gating kinetics. In order to explore the rescue function of All on decreased sodium peak current, we used confocal microscopy and Western blot to detect the expression of channel proteins in the cell membrane. We found a significant increase in sodium peak current of the 30 μmol·L^-1 All HEK293 cells（269.8 ± 16.6 p A/p F, P〈0.01）, almost closed to the current density of the control group（298.2 ± 17.5 p A/p F, P〈0.01）. All allowed the steady-state inactivation of the channel to move toward a more positive direction（V1/2, inact returns to-79.5 ± 2.4 mV, P〈0.01）. It also slowed the intermediate state inactivation of the channel（inactivation prolongated to 598.1 ± 22.6 ms, P〈0.01）. Meanwhile, All increased distribution and expression of the channel protein in the cell membrane（compared to F1473 S, P〈0.01）. All caused an increase of current in SCN5A-F1473 S mutation cells. We consider that the main mechanism may be related to the reduced channel inactivation by the drug with an improvement of the migration barrier of the mutational channel.