Heterogeneity in expression and subcellular localization of claudins 2, 3, 4, and 5 in the rat liver, pancreas, and gut
Heterogeneity in expression and subcellular localization of claudins 2, 3, 4, and 5 in the rat liver, pancreas, and gut
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DOI：
10.1053/gast.2001.21736
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发表时间：
2001-02-01
期刊：
影响因子：
29.4
通讯作者：
Anderson, JM
中科院分区：
文献类型：
--
作者：
Rahner, C;Mitic, LL;Anderson, JM
背景与目的：胃肠道上皮细胞的细胞旁转运差异很大。我们确定紧密连接蛋白家族成员的差异表达是否与产生这些可变特性的潜在作用一致。方法：制备兔抗claudins 2至5肽的多克隆抗体。通过免疫印迹法检测单个claudins的分布，并通过免疫荧光法测定其在大鼠肝脏、胰腺、胃、小肠和大肠冷冻切片上的细胞类型和亚细胞定位。结果如下：所有抗体在免疫印迹上检测到预期大小的单一条带，并且基于肽竞争研究是单特异性的。免疫印迹检测到各紧密连接蛋白的表达水平在组织之间的强烈差异。免疫定位证实了这些差异，并揭示了显着的变化表达模式。在肝脏中，紧密连接蛋白2显示从门静脉周围到中央周围肝细胞的小叶梯度增加，紧密连接蛋白3均匀表达，紧密连接蛋白4不存在，紧密连接蛋白5仅在内皮连接中表达。在胰腺中，紧密连接蛋白2仅在导管上皮的连接处检测到，紧密连接蛋白5仅在腺泡细胞的连接处检测到，而紧密连接蛋白3和4在两者中都检测到。在肠道中的差异中有密封蛋白2的隐窝-绒毛减少，密封蛋白4对结肠表面细胞的高度限制性表达，以及发现一些密封蛋白可以是连接性的、侧向的，或者沿着隐窝-绒毛表面轴显示连接性与侧向定位的梯度。结论：Claudins在胃肠道组织中的表达存在差异。我们提出这些模式的基础上的细胞旁渗透性的差异，如电阻和离子选择性，将补充已知的差异，跨细胞运输。
Background & Aims: Paracellular transport varies widely among epithelia of the gastrointestinal tract. We determined whether members of the claudin family of tight junction proteins ave differentially expressed consistent with a potential role in creating these variable properties. Methods: Rabbit polyclonal antibodies were produced against peptides from claudins 2 through 5. The distribution of individual claudins was detected by immunoblotting, and their cell type and subcellular localization were determined by immunofluorescence on cryosections of rat liver, pancreas, stomach, and small and large intestine. Results: All antibodies detected single bands of the expected size on immunoblots and were monospecific based on peptide competition studies, Immunoblotting detected strong differences among tissues in the expression level of each claudin. Immunolocalization confirmed these differences and revealed striking variations in expression patterns. In the liver, claudin 2 shows a lobular gradient increasing from periportal to pericentral hepatocytes, claudin 3 is uniformly expressed, claudin 4 is absent, and claudin 5 is only expressed in endothelial junctions. In the pancreas, claudin 2 is only detected in junctions of the duct epithelia, claudin 5 only in junctions of acinar cells, whereas claudin 3 and 4 are in both. Among differences in the gut are a crypt-to-villus decrease in claudin 2, a highly restricted expression of claudin 4 to colonic surface cells, and the finding that some claudins can be junctional, lateral, or show a gradient in junctional vs. lateral localization along the crypt-to-villus surface axis. Conclusions: Claudins have very different expression patterns among and within gastrointestinal tissues. We propose these patterns underlie differences in paracellular permeability properties, such as electrical resistance and ion selectivity that would complement known differences in transcellular transport.