PDF(Pubmed)
Abstract：
The cardiac sodium channel Nav1.5 is a key contributor to the cardiac action potential, and dysregulations in Nav1.5 can lead to cardiac arrhythmias. Nav1.5 is a target of numerous antiarrhythmic drugs (AADs). Previous studies identified the protein 14-3-3 as a regulator of Nav1.5 biophysical coupling. Inhibition of 14-3-3 can remove the Nav1.5 functional coupling and has been shown to inhibit the dominant-negative effect of Brugada syndrome mutations. However, it is unknown whether the coupling regulation is involved with AADs\' modulation of Nav1.5. Indeed, AADs could reveal important structural and functional information about Nav1.5 coupling. Here, we investigated the modulation of Nav1.5 by four classic AADs, quinidine, lidocaine, mexiletine, and flecainide, in the presence of 14-3-3 inhibition. The experiments were carried out by high-throughput patch-clamp experiments in an HEK293 Nav1.5 stable cell line. We found that 14-3-3 inhibition can enhance acute block by quinidine, whereas the block by other drugs was not affected. We also saw changes in the use- and dose-dependency of quinidine, lidocaine, and mexiletine when inhibiting 14-3-3. Inhibiting 14-3-3 also shifted the channel activation toward hyperpolarized voltages in the presence of the four drugs studied and slowed the recovery of inactivation in the presence of quinidine. Our results demonstrated that the protein 14-3-3 and Nav1.5 coupling could impact the effects of AADs. Therefore, 14-3-3 and Nav1.5 coupling are new mechanisms to consider in the development of drugs targeting Nav1.5. SIGNIFICANCE STATEMENT: The cardiac sodium channel Nav1.5 is a target of commonly used antiarrhythmic drugs, and Nav1.5 function is regulated by the protein 14-3-3. The present study demonstrated that the regulation of Nav1.5 by 14-3-3 influences Nav1.5\'s response to antiarrhythmic drugs. This study provides detailed information about how 14-3-3 differentially regulated Nav1.5 functions under the influence of different drug subtypes. These findings will guide future molecular studies investigating Nav1.5 and antiarrhythmic drugs outcomes.
摘要：
心脏钠通道Nav1.5是心脏动作电位的关键因素，Nav1.5中的失调可导致心律失常。Nav1.5是许多抗心律失常药物（AAD）的靶标。先前的研究将蛋白质14-3-3鉴定为Nav1.5生物物理偶联的调节剂。抑制14-3-3可以去除Nav1.5功能偶联，并已显示抑制Brugada综合征突变的显性负作用。然而,目前尚不清楚耦合调节是否与Nav1.5的AAD调制有关。的确,AAD可以揭示有关Nav1.5耦合的重要结构和功能信息。在这里，我们研究了四个经典AAD对Nav1.5的调制，奎尼丁,利多卡因,美西律,和氟卡尼,在存在14-3-3抑制的情况下。通过在HEK293Nav1.5稳定细胞系中的高通量膜片钳实验进行实验。我们发现14-3-3抑制可以增强奎尼丁的急性阻滞，而其他药物的阻断没有受到影响。我们还看到了奎尼丁的使用和剂量依赖性的变化，利多卡因,和美西律抑制14-3-3时。在所研究的四种药物存在下，抑制14-3-3也使通道激活向超极化电压移动，并在奎尼丁存在下减缓失活的恢复。我们的结果表明，蛋白质14-3-3和Nav1.5偶联可以影响AAD的作用。因此,14-3-3和Nav1.5偶联是开发靶向Nav1.5的药物时要考虑的新机制。意义声明心脏钠通道Nav1.5是常用抗心律失常药物的靶标，Nav1.5功能受蛋白质14-3-3调节。本研究表明，14-3-3对Nav1.5的调节会影响Nav1.5对抗心律失常药物的反应。我们提供了有关14-3-3在不同药物亚型的影响下如何差异调节Nav1.5功能的详细信息。我们的发现将指导未来研究Nav1.5和抗心律失常药物结果的分子研究。
