Differential expression of E-cadherin, N-cadherin and beta-catenin in proximal and distal segments of the rat nephron.
Differential expression of E-cadherin, N-cadherin and beta-catenin in proximal and distal segments of the rat nephron.
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DOI：
10.1186/1472-6793-4-10
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发表时间：
2004-05-17
期刊：
影响因子：
--
通讯作者：
Appelt DM
中科院分区：
文献类型：
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作者：
Prozialeck WC;Lamar PC;Appelt DM
经典的钙粘附素如E-和N-钙粘附素是钙离子依赖的细胞黏附分子，在肾上皮极性的发生和维持中起着重要作用。最近的研究表明，各种钙粘附素存在于肾脏中，并在肾单位的不同节段有不同的表达。然而，由于不同的研究聚焦于不同的钙粘附素小组并使用不同的物种，这些发现的解释变得复杂起来。此外，由于以前的研究只有几个集中在大鼠身上，关于肾脏钙粘附素在这一重要物种中的表达和定位的信息缺乏。在本研究中，我们使用了双重免疫荧光标记程序，利用针对E-或N-钙粘素的特异性抗体，以及针对特定肾单位节段的标记的抗体，来表征成年大鼠肾脏冰冻切片中钙粘附素的表达模式。结果表明，N-钙粘蛋白是近曲小管中主要的钙粘附素，但在其他肾单位节段中基本不存在。相反，E-钙粘附素在远端小管、集合管和大多数髓质节段中含量丰富，但仅在近端小管中存在于非常低的水平。其他结果显示，在近端小管的不同节段，N-钙粘附素的标记模式不同。S1和S2节段在顶端细胞表面呈现细丝状的标记图案，而S3节段在细胞-细胞接触的外侧显示出强烈的标记。这些结果表明，E-钙粘蛋白和N-钙粘蛋白在大鼠肾脏近端小管和远端小管有不同的表达，这可能是不同肾单位段对肾脏病理或肾毒性损伤易感性不同的原因之一。
The classical cadherins such as E- and N-cadherin are Ca2+-dependent cell adhesion molecules that play important roles in the development and maintenance of renal epithelial polarity. Recent studies have shown that a variety of cadherins are present in the kidney and are differentially expressed in various segments of the nephron. However, the interpretation of these findings has been complicated by the fact that the various studies focused on different panels of cadherins and utilized different species. Moreover, since only a few of the previous studies focused on the rat, information regarding the expression and localization of renal cadherins in this important species is lacking. In the present study, we have employed dual immunofluorescent labeling procedures that utilized specific antibodies against either E- or N-cadherin, along with antibodies that target markers for specific nephron segments, to characterize the patterns of cadherin expression in frozen sections of adult rat kidney. The results showed that N-cadherin is the predominant cadherin in the proximal tubule, but is essentially absent in other nephron segments. By contrast, E-cadherin is abundant in the distal tubule, collecting duct and most medullary segments, but is present only at very low levels in the proximal tubule. Additional results revealed different patterns of N-cadherin labeling along various segments of the proximal tubule. The S1 and S2 segments exhibit a fine threadlike pattern of labeling at the apical cell surface, whereas the S3 segment show intense labeling at the lateral cell-cell contacts. These results indicate that E- and N-cadherin are differentially expressed in the proximal and distal tubules of rat kidney and they raise the possibility that differences in cadherin expression and localization may contribute to the differences in the susceptibility of various nephron segments to renal pathology or nephrotoxic injury.