Occludin immunolocalization and protein expression in goldfish
Occludin immunolocalization and protein expression in goldfish
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DOI：
10.1242/jeb.014894
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发表时间：
2008-05-15
影响因子：
2.8
通讯作者：
Kelly, Scott P.
中科院分区：
文献类型：
--
作者：
Chasiotis, Helen;Kelly, Scott P.
紧密连接（TJs）是一个不可分割的组成部分的模型，说明跨鱼类上皮细胞的离子转运机制，然而，鲜为人知的是，TJ蛋白在鱼类。利用免疫组织化学方法和Western blot分析，我们研究了occludin，一个跨膜TJ蛋白，在金鱼组织中的定位和表达。在金鱼鳃，不连续occludin免疫染色检测到沿着边缘的次级鳃板和部分的interlamellar区域，线的侧壁的中央静脉窦。在金鱼肠，occludin免疫定位在TJ特异性分布模式的柱状上皮细胞内衬肠腔的顶端区域。在金鱼肾脏中，occludin在肾单位的离散区域中差异表达。Occludin免疫染色在肾单位远段最强，在集合管中等，在近段缺席。为了探讨occludin在维持鱼类水矿物平衡中的潜在作用，我们对金鱼进行了1，2和4周的食物剥夺，然后检测了鳃，肠和肾脏中的水矿物状态，Na+，K+-ATP酶活性和occludin蛋白表达的终点。Occludin的表达改变响应于水矿物质的不平衡，在组织特异性的方式，这表明TJ蛋白在调节鱼类上皮通透性的动态作用。
Tight junctions (TJs) are an integral component of models illustrating ion transport mechanisms across fish epithelia; however, little is known about TJ proteins in fishes. Using immunohistochemical methods and Western blot analysis, we examined the localization and expression of occludin, a transmembrane TJ protein, in goldfish tissues. In goldfish gills, discontinuous occludin immunostaining was detected along the edges of secondary gill lamellae and within parts of the interlamellar region that line the lateral walls of the central venous sinus. In the goldfish intestine, occludin immunolocalized in a TJ-specific distribution pattern to apical regions of columnar epithelial cells lining the intestinal lumen. In the goldfish kidney, occludin was differentially expressed in discrete regions of the nephron. Occludin immunostaining was strongest in the distal segment of the nephron, moderate in the collecting duct and absent in the proximal segment. To investigate a potential role for occludin in the maintenance of the hydromineral balance of fishes, we subjected goldfish to 1, 2 and 4 weeks of food deprivation, and then examined the endpoints of hydromineral status, Na+, K+-ATPase activity and occludin protein expression in the gills, intestine and kidney. Occludin expression altered in response to hydromineral imbalance in a tissue-specific manner suggesting a dynamic role for this TJ protein in the regulation of epithelial permeability in fishes.