Angiogenic Functions of Voltage-gated Na+ Channels in Human Endothelial Cells MODULATION OF VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) SIGNALING
Angiogenic Functions of Voltage-gated Na+ Channels in Human Endothelial Cells MODULATION OF VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) SIGNALING
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DOI：
10.1074/jbc.m110.187559
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发表时间：
2011-05-13
影响因子：
4.8
通讯作者：
Djamgoz, Mustafa B. A.
中科院分区：
文献类型：
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作者：
Andrikopoulos, Petros;Fraser, Scott P.;Djamgoz, Mustafa B. A.
电压门控钠通道（VGSC）活性先前已在内皮细胞（EC）中报道。然而，目前尚未研究VGSC的确切亚型、其作用模式和在血管生成中的潜在作用。本研究的主要目的是确定VGSC活性在血管生成功能中的作用，并以人脐静脉内皮细胞（HUVECs）为模型系统阐明潜在相关的信号转导机制。实时PCR显示HUVEC中主要功能性VGSC α和β亚基亚型为Nav1.5、Nav1.7、VGSC β 1和VGSC β 3。Western印迹证实VGSC α蛋白在HUVEC中表达，免疫组织化学显示VGSC α在体内小鼠主动脉EC中表达。电生理记录表明，通道的功能和河豚毒素（TTX）的抑制。VGSC活性调节HUVECs的以下血管生成特性：VEGF诱导的增殖或趋化性、肾小管分化和基质粘附。有趣的是，基于TTX敏感性和siRNA介导的基因沉默的影响，血管生成的不同方面由不同的VGSC亚型控制。此外，我们首次发现TTX抗性（TTX-R）VGSC（Nav1.5）通过PKC α-B-RAF信号传导轴增强VEGF诱导的ERK 1/2激活。我们推测这种增强作用是通过调节VEGF诱导的HUVEC去极化和[Ca 2 +]（i）而发生的。我们的结论是，VGSC调节多种血管生成功能和VEGF信号在HUVECs。我们的研究结果表明，靶向VGSC表达/活性可能是控制血管生成的新策略。
Voltage-gated sodium channel (VGSC) activity has previously been reported in endothelial cells (ECs). However, the exact isoforms of VGSCs present, their mode(s) of action, and potential role(s) in angiogenesis have not been investigated. The main aims of this study were to determine the role of VGSC activity in angiogenic functions and to elucidate the potentially associated signaling mechanisms using human umbilical vein endothelial cells (HUVECs) as a model system. Real-time PCR showed that the primary functional VGSC alpha- and beta-subunit isoforms in HUVECs were Nav1.5, Nav1.7, VGSC beta 1, and VGSC beta 3. Western blots verified that VGSC alpha proteins were expressed in HUVECs, and immunohistochemistry revealed VGSC alpha expression in mouse aortic ECs in vivo. Electrophysiological recordings showed that the channels were functional and suppressed by tetrodotoxin (TTX). VGSC activity modulated the following angiogenic properties of HUVECs: VEGF-induced proliferation or chemotaxis, tubular differentiation, and substrate adhesion. Interestingly, different aspects of angiogenesis were controlled by the different VGSC isoforms based on TTX sensitivity and effects of siRNA-mediated gene silencing. Additionally, we show for the first time that TTX-resistant (TTX-R) VGSCs (Nav1.5) potentiate VEGF-induced ERK1/2 activation through the PKC alpha-B-RAF signaling axis. We postulate that this potentiation occurs through modulation of VEGF-induced HUVEC depolarization and [Ca2+](i). We conclude that VGSCs regulate multiple angiogenic functions and VEGF signaling in HUVECs. Our results imply that targeting VGSC expression/activity could be a novel strategy for controlling angiogenesis.