通阳活血方经KChIP2调控Ito和胞内钙对心衰触发性心律失常的机制研究

The heart failure with malignant arrhythmia has higher morbidity and mortality. Tong Yang Huoxue Recipe is an effective original prescription of “Master of TCM” Liu Zhiming. Previous clinical study found that the recipe is safe and effective in both the heart failure and arrhythmia patients. The basic research has found that the recipe can shorten action potential duration by augmenting the transient outward potassium current (Ito) in sinoatrial node cells and it can suppress calcium overload.Rencent researches imply that the Ito and intracellular calcium overload plays significant roles in heart failure with triggered arrhythmia. And the kv channel-interacting proteins (KChIP2) plays key regulatory role on Ito and intracellular calcium. According to above data we have the hypothesis: Tong Yang Huoxue Recipe may regulate the Ito and intracellular calcium through the KChIP2 in cardiomyocytes of heart failure, maintaining the calcium homeostasis, which can reduce the incidence of the malignant arrhythmia. This project is firstly using patch-clamp, laser confocal and other techniques to explore Tongyang Huoxue Recipe’ effects on triggering activity, channel current, intracellular calcium, KChIP2 and related molecules of cardiomyocyte in Yang deficiency and blood stasis syndrome heart failure rats. And then constructing the model of overexpression and knockdown of KChIP2 gene in cardiomyocytes to clarify the role of KChIP2 in the Tongyang Huoxue Recipe’s effect on the regulation of the Ito and intracellular calcium. The aim of this study was to reveal the cellular electrophysiological and molecular mechanism of Tongyang Huoxue Recipe’s on preventing and treating triggered arrhythmia in heart failure.

慢性心力衰竭恶性心律失常的发病率、致死率高。通阳活血方是“国医大师”刘志明治疗慢性心衰和心律失常的有效原创方，前期临床观察该方安全有效；基础研究发现其能通过增加窦房结细胞瞬时外向钾电流（Ito）缩短动作电位时程，并能抑制细胞内钙超载。新近研究显示，Ito和细胞内钙超载是导致心衰触发性心律失常的关键，而钾通道相互作用蛋白2（KChIP2）对Ito和胞内钙均有关键性调节效应。据此假设：通阳活血方可能通过KChIP2调控心衰心肌细胞Ito及胞内钙，维持钙稳态，进而减少恶性心律失常发生。本项目首先拟采用全细胞膜片钳、激光共聚焦等技术研究通阳活血方对心衰阳虚血瘀证大鼠心肌细胞触发活动、通道电流、胞内钙、KChIP2及相关分子的影响，进而敲低/过表达心肌细胞KChIP2，探讨该方是否通过KChIP2调控Ito及胞内钙起作用，旨在揭示通阳活血方防治心衰触发性心律失常的细胞电生理和分子机制。

慢性心力衰竭恶性心律失常的发病率、致死率高。通阳活血方是“国医大师”刘志明治疗 慢性心衰和心律失常的有效原创方，前期临床观察该方安全有效；基础研究发现其能通过增加窦房结细胞瞬时外向钾电流（Ito）缩短动作电位时程，并能抑制细胞内钙超载。最新研究进展显示，Ito和细胞内钙超载是导致心衰触发性心律失常的关键，而钾通道相互作用蛋白2（KChIP2 ）对Ito和胞内钙均有关键性调节效应。因此本项目首先拟采用全细胞膜片钳、激光共聚焦等技术研究通阳活血方对心衰阳虚血瘀证大鼠心肌细胞触发活动、通道电流、胞内钙、KChIP2及相关分子的影响，进而敲低/过表达心肌细胞KChIP2，探讨该方是否通过KChIP2调控Ito及胞内钙起作用，旨在揭示通阳活血方防治心衰触发性心律失常的细胞电生理和分 子机制。研究结果显示：通阳活血方能提高慢性心力衰竭阳虚血瘀证大鼠EF值，改善收缩功能，降低心衰大鼠室性心律失常发生，保护心衰大鼠心肌组织结构，降低心衰大鼠血清白介素6及肿瘤坏死因子水平，可提高心衰大鼠心肌组织钾通道相关KChIP2、Kv4.3 mRNA和蛋白表达，下调钙转运分子RyR2、Cav1.2 mRNA和蛋白表达，上调钙转运分子SERCA2a mRNA和蛋白表达，减少心肌细胞触发活动，缩短动作电位时程，增强Ito电流、降低Ica-L电流，增加心肌细胞钙瞬变和收缩及舒张期钙，调节钙稳态，其作用机制可能是通过KChIP2起作用。该项目对深入研究中医药尤其是名老中医经验方治疗心衰具有深远意义。