Mutagenesis of the epithelial polarity gene, discs large 1, perturbs nephrogenesis in the developing mouse kidney
Mutagenesis of the epithelial polarity gene, discs large 1, perturbs nephrogenesis in the developing mouse kidney
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DOI：
10.1111/j.1523-1755.2005.00489.x
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发表时间：
2005-09-01
影响因子：
19.6
通讯作者：
Caruana, G
中科院分区：
文献类型：
--
作者：
Naim, E;Bernstein, A;Caruana, G
背景资料。在哺乳动物永久肾脏(后肾)的发育过程中，会发生一些关键的上皮事件，如输尿管分支、形态发生和肾脏发生。肾脏发生的最初阶段之一涉及间充质细胞向上皮细胞的转化，因此后肾为研究上皮细胞极化提供了一个很好的模型。本研究旨在探讨上皮极性基因Diss Large 1(Dlg1)在小鼠肾脏发育过程中的作用。我们利用了在Dlg1(DLG(GT))内插入基因陷阱载体的小鼠，导致Dlg1蛋白被截断，缺少SH3，蛋白4.1和鸟苷晚期蛋白样蛋白(GUK)结构域，与LacZ报告基因融合。这些小鼠被用来分析Dlg1在肾脏发育过程中的表达，Dlg1在上皮细胞中的亚细胞定位，以及Dlg1与钙调蛋白相关丝氨酸/苏氨酸激酶(CASK)结合的能力。用后肾器官培养法研究了野生型和Dlg(Gt)突变小鼠的分枝形态发生和肾脏发生。在肾脏发育过程中，Dlg1在输尿管和间质来源的上皮细胞中均有表达。Dlg1的截短改变了Dlg1的正常基侧定位，将其限制在粘着连接。由于SH3结构域的缺失，Dlg1与CASK的结合能力降低。DLG(GT)/DLG(GT)后肾的肾小球发生改变，肾单位数目减少30%。我们的结果表明，Dlg1的SH3、蛋白4.1和/或GUK结构域的缺失扰乱了上皮的极性，扰乱了肾脏的发生，这可能是输尿管分支形态发生缺陷和/或间质向上皮转化延迟的次要后果。
Background. During development of the permanent mammalian kidney (metanephros) several key epithelial events occur such as ureteric branching morphogenesis and nephrogenesis. One of the first stages of nephrogenesis involves the conversion of mesenchymal cells to epithelial cells, and thus the metanephros provides an excellent model to study epithelial polarization. The aim of this study was to investigate the role of the epithelial polarity gene, discs large 1 (dlg1), during development of the mouse kidney.Methods. We utilized mice with a gene trap vector insertion within dlg1 (dlg(gt)) resulting in a truncated Dlg1 protein, lacking the SH3, protein 4.1 and guanylate kinase-like (GUK) domains, fused to a LacZ reporter. These mice were used to analyze the expression of Dlg1 during kidney development, the subcellular localization of Dlg1 in epithelial cells, and the ability of Dlg1 to bind to calmodulin-associated serine/threonine kinase (CASK). Metanephric organ culture was used to study branching morphogenesis and nephrogenesis in wild-type and dlg(gt) mutant mice.Results. Dlg1 was expressed in ureteric and mesenchyme-derived epithelial cells during kidney development. Truncation of Dlg1 altered the normal basolateral localization of Dlg1 restricting it to the adherens junction. Due to the loss of the SH3 domain the binding capacity of Dlg1 to CASK was reduced. Nephrogenesis was altered in dlg(gt)/dlg(gt) metanephroi with a 30% decrease in nephron number.Conclusion. Our results indicate that the loss of the SH3, protein 4.1 and/or GUK domains of Dlg1 disrupt epithelial polarity and perturb nephrogenesis either as a secondary consequence to a defect in ureteric branching morphogenesis and/or delay in mesenchyme-to- epithelial transition.