Flow regulates intercellular communication in HAEC by assembling functional Cx40 and Cx37 gap junctional channels
Flow regulates intercellular communication in HAEC by assembling functional Cx40 and Cx37 gap junctional channels
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DOI：
10.1152/ajpheart.00204.2005
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发表时间：
2006-05-01
影响因子：
4.8
通讯作者：
DePaola, N
中科院分区：
文献类型：
--
作者：
Ebong, EE;Kim, S;DePaola, N
离子和小信号分子通过间隙连接的直接细胞间转移在血管壁稳态中起关键作用。血管内皮间隙连接通道由连接蛋白（Cx）蛋白Cx 37、Cx40和Cx43形成。调节连接蛋白表达和组装成功能通道的机制尚未完全确定。我们研究了流体流动对内皮细胞间隙连接细胞间通讯（GJIC）的动态调节以及每个血管连接蛋白在体外功能性人内皮细胞间隙连接中的参与。将人主动脉内皮细胞（HAEC）暴露于平行板流动室中的生理流动中5、16和24 h。免疫细胞化学法检测连接蛋白的表达和定位，染料注射法检测GJIC功能。连接蛋白模拟肽抑制剂用于评估功能通道的特定连接蛋白组成。尽管Cx43和Cx40在细胞与细胞的贴壁处有丰富的表达，但培养的HAEC单层显示出显著低水平的基线功能通讯。暴露于血流后，通过染料扩散的GJIC显示出较基线水平显著的时间依赖性增加，在24小时内达到7.5倍。抑制研究表明，这种反应主要是由Cx40介导的，与其他两个血管连接蛋白组装成功能同型和/或异型通道的贡献较小。这是第一个研究表明，流量同时和差异调节的Cx 37，Cx40和Cx43蛋白的表达，并参与增强细胞间通信的染料转移在体外人内皮细胞。
Direct cell-to-cell transfer of ions and small signaling molecules via gap junctions plays a key role in vessel wall homeostasis. Vascular endothelial gap junctional channels are formed by the connexin (Cx) proteins Cx37, Cx40, and Cx43. The mechanisms regulating connexin expression and assembly into functional channels have not been fully identified. We investigated the dynamic regulation of endothelial gap junctional intercellular communication (GJIC) by fluid flow and the participation of each vascular connexin in functional human endothelial gap junctions in vitro. Human aortic endothelial cells (HAEC) were exposed for 5, 16, and 24 h to physiological flows in a parallel-plate flow chamber. Connexin protein expression and localization were evaluated by immunocytochemistry, and functional GJIC was evaluated by dye injection. Connexin-mimetic peptide inhibitors were used to assess the specific connexin composition of functional channels. HAEC monolayers in culture exhibited baseline functional communication at a striking low level despite abundant expression of Cx43 and Cx40 localized at cell-to-cell appositions. Upon exposure to flow, GJIC by dye spread demonstrated a significant time-dependent increase from baseline levels, reaching 7.5-fold in 24 h. Inhibition studies revealed that this response was mediated primarily by Cx40, with lesser contributions of the other two vascular connexins assembled into functional homotypic and/or heterotypic channels. This is the first study to demonstrate that flow simultaneously and differentially regulates expression of the Cx37, Cx40, and Cx43 proteins and their involvement in the augmentation of intercellular communication by dye transfer in human endothelial cells in vitro.