Heterogeneity in expression and subcellular localization of tight junction proteins, claudin-10 and-15, examined by RT-PCR and immunofluorescence microscopy
Heterogeneity in expression and subcellular localization of tight junction proteins, claudin-10 and-15, examined by RT-PCR and immunofluorescence microscopy
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DOI：
10.1679/aohc.68.349
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发表时间：
2005-12-01
影响因子：
--
通讯作者：
Shibata, Y
中科院分区：
文献类型：
--
作者：
Inai, T;Sengoku, A;Shibata, Y
紧密连接调节细胞旁通透性，创造血管和消化道的腔液微环境，并且还在包括表皮的复层上皮中形成保护屏障。claudin是紧密连接处的膜蛋白，形成一个至少由24个成员组成的多基因家族，但每个claudin的亚细胞定位的知识仍然是零碎的。我们对15种claudin进行了RT-PCR，以检测其在小鼠各种组织中的mRNA表达，并通过免疫荧光显微镜重点研究了claudin-10和-15在大鼠各种组织中的亚细胞定位。在大多数组织的血管内皮细胞中均未检测到claudin-10或-15，并且这些claudin仅限于肾髓质中的直小血管。在空肠上皮的顶端紧密连接处也检测到两种claudin，沿隐窝-绒毛轴沿着没有强度梯度。然而，两种claudin仅在结肠中的隐窝上皮的基底半部中表达，显示出沿沿着隐窝-表面轴的明显梯度。此外，claudin-10显示出不存在紧密连接链的异位亚细胞定位。Claudin-10被检测到沿着整个侧膜的腺泡细胞，除了在外分泌腺的顶端紧密连接，并在细胞质中的复层上皮，包括背侧皮肤和皮肤胃的基底细胞。claudin-10和claudin-15在组织中的这些不均匀分布可能与组织间细胞旁通透性的差异有关。
Tight junctions regulate paracellular permeability, create the luminal fluid microenvironment of blood vessels and the digestive tract, and also form the protective barrier in the stratified epithelium including the epidermis. Claudins are the integral membrane proteins at tight junctions and form a multigene family composed of at least 24 members, but knowledge of the subcellular localization of each claudin is still fragmentary. We performed RT-PCR for fifteen claudin species to examine the mRNA expression in various mouse tissues, and focused on investigating the subcellular localization of claudin-10 and -15 by immunofluorescence microscopy in various rat tissues. Neither claudin-10 nor -15 was detected in vascular endothelial cells in most tissues, and these claudins were restricted to the vasa recta in the kidney medulla. Both claudins were also detected at apical tight junctions in the epithelium of the jejunum with no intensity gradients along the crypt-to-villus axis. However, both claudins were expressed only in the basal half of the crypt epithelium in the colon, showing obvious gradients along crypt-to-surface axis. Moreover, claudin-10 showed the ectopic subcellular localization where tight junction strands do not exist. Claudin-10 was detected along the entire lateral membranes of acinar cells in addition to the apical tight junctions in exocrine glands, and in the cytoplasm of basal cells in the stratified epithelium including the dorsal skin and cutaneous stomach. These heterogeneous distributions of claudin-10 and -15 in tissues may be related to the differences in paracellular permeability among tissues.