Claudins in the tight junctions of stria vascularis marginal cells
Claudins in the tight junctions of stria vascularis marginal cells
复制标题
DOI：
10.1016/s0006-291x(03)00498-4
复制
发表时间：
2003-04-25
影响因子：
3.1
通讯作者：
Gitter, AH
中科院分区：
文献类型：
--
作者：
Florian, P;Amasheh, S;Gitter, AH
在哺乳动物的耳蜗里，在边缘细胞和其他内耳上皮细胞的冰冻断裂图上可以看到紧密的连接链。然而，工业紧密连接的分子组成在很大程度上是未知的。我们研究了完整紧密连接蛋白claudin-1至-4和occludin在豚鼠耳蜗纹和肾脏中的表达。Western印迹分析显示Claudin-4和occludin在皱纹组织中有较强的表达，共聚焦免疫荧光显微镜显示它们存在于边缘细胞的紧密连接中。此外，还检测到中等水平的claudin-3和claudin-1，两者都位于边缘紧密连接。Claudins-1、-3和-4是低细胞旁通透性的上皮细胞的特征，而claudin-4是已知的限制阳离子通过上皮紧密连接的通道。在边缘细胞中，这些克拉丁似乎负责将富钾内淋巴与富钠内淋巴液分离。相反，Western印迹分析和共聚焦显微镜显示边缘细胞上皮不含claudin-2，后者在紧密连接处形成阳离子选择性孔洞。它的缺失表明边缘细胞中存在一种阳离子紧密的细胞旁途径。(C)2003年埃尔塞维尔科学公司(美国)。版权所有。
In the mammalian cochlea, tight junctional strands are visible on freeze fracture images of marginal cells and other inner ear epithelia. The molecular composition of the strial tight junctions is, however, largely unknown. We investigated the expression of integral tight junction-proteins, claudin-1 to -4, and occludin, in stria vascularis of the guinea-pig cochlea, as compared to kidney. Western blot analysis revealed a strong expression of claudin-4 and occludin in strial tissue, and confocal immunofluorescence microscopy demonstrated their presence in the tight junctions of the marginal cells. In addition, a moderate level of claudin-3 and claudin-1 was detected and both were located in the marginal tight junctions. Claudins-1, -3, and -4 are characteristic of epithelia with low paracellular permeability and claudin-4 is known to restrict the passage of cations through epithelial tight junctions. In the marginal cells, these claudins appear to be responsible for the separation of the potassium-rich endolymph from the sodium-rich intrastrial fluid. In contrast, Western blot analysis and confocal microscopy demonstrated that the marginal cell epithelium does not contain claudin-2, which forms a cation-selective pore in tight junctions. Its absence indicates a cation-tight paracellular pathway in the marginal cells. (C) 2003 Elsevier Science (USA). All rights reserved.