Extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells
Extracellular-loop peptide antibodies reveal a predominant hemichannel organization of connexins in polarized intestinal cells
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DOI：
10.1016/j.yexcr.2007.12.021
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发表时间：
2008-04-01
影响因子：
3.7
通讯作者：
Van Nlieu, Guy Tran
中科院分区：
文献类型：
--
作者：
Clair, Caroline;Combettes, Laurent;Van Nlieu, Guy Tran
志贺氏菌是细菌性痢疾的病原体，它侵入结肠上皮细胞，引起强烈的炎症反应，导致粘膜破坏。此前研究表明，连接蛋白 (Cx) 半通道开放诱导的 ATP 依赖性旁分泌信号有利于福氏志贺氏菌在 HeLa 细胞转染子中的入侵和传播 [G. Tran Van Nhieu、C. Clair、R. Bruzzone、M. Mesnil、P. Sansonetti 和 L. Combettes。 （2003）。连接蛋白依赖性细胞间通讯增加了志贺氏菌在上皮细胞中的侵袭和传播。纳特。细胞生物学。 5、720-726。]。然而，尽管 Cxs 已在极化上皮细胞中被描述，但对其结构组织和半通道在福氏链球菌入侵过程中的作用知之甚少。我们在此表明，极化的 Caco-2/TC7 细胞表达大量的 Cx26、Cx32 和 Cx43，但出乎意料的是，通过染料转移实验评估的细胞间偶联效率低下。与半通道中主要的 Cx 组织一致，很容易观察到低钙诱导的染料负载，并且优先负载在基底外侧。针对连接蛋白胞外环肽 (CELAbs) 的抗体 (Abs) 证明了半通道信号传导的重要性，因为它们在福氏链霉入侵期间在低钙和生理钙浓度下抑制染料摄取。重要的是，CELabs 允许上皮细胞表面的半通道可视化，作为与间隙细胞间连接不同的结构。 (C) 2008 Elsevier Inc. 保留所有权利。
Shigella, the causative agent of bacillary dysentery, invades colonic epithelial cells to elicit an intense inflammatory reaction leading to destruction of the mucosa. ATP-dependent paracrine signalling induced by connexin (Cx) hemichannel opening was previously shown to favor Shigella flexneri invasion and dissemination in transfectants of HeLa cells [G. Tran Van Nhieu, C. Clair, R. Bruzzone, M. Mesnil, P. Sansonetti and L. Combettes. (2003). Connexin-dependent intercellular communication increases invasion and dissemination of Shigella in epithelial cells. Nat. Cell Biol. 5, 720-726.]. However, although Cxs have been described in polarized epithelial cells, little is known about their structural organization and the role of hemichannels during S. flexneri invasion. We show here that polarized Caco-2/TC7 cells express significant amounts of Cx26, Cx32 and Cx43, but that unexpectedly, cell-cell coupling assessed by dye-transfer experiments is inefficient. Consistent with a predominant Cx organization in hemichannels, dye loading induced by low calcium was readily observed, with preferential loading at the basolateral side. Antibodies (Abs) against connexin extracellular loop peptides (CELAbs) demonstrated the importance of hemichannel signalling since they inhibited dye uptake at low calcium and at physiological calcium concentrations during S.flexneri invasion. Importantly, CELAbs allowed the visualization of hemichannels at the surface of epithelial cells, as structures distinct from gap intercellular junctions. (C) 2008 Elsevier Inc. All rights reserved.