Loss of occludin and functional tight junctions, but not ZO-1, during neural tube closure - Remodeling of the neuroepithelium prior to neurogenesis
Loss of occludin and functional tight junctions, but not ZO-1, during neural tube closure - Remodeling of the neuroepithelium prior to neurogenesis
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DOI：
10.1006/dbio.1996.0336
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发表时间：
1996-12-15
影响因子：
2.7
通讯作者：
Huttner, WB
中科院分区：
文献类型：
--
作者：
AakuSaraste, E;Hellwig, A;Huttner, WB
神经上皮细胞可以产生非上皮性细胞，即神经元。在这里，我们通过检测从神经板到神经管的紧密连接的分子成分的存在，对鸡和小鼠胚胎在神经发生的背景下神经上皮细胞的上皮特征进行了研究。Occludin是一种紧密连接的跨膜蛋白，在整个鸡神经板的神经上皮细胞侧膜的顶端检测到免疫反应。在神经管关闭过程中，闭塞蛋白从所有神经上皮细胞中消失。相应地，通过将辣根过氧化物酶注射到小鼠胚胎羊膜腔内，将辣根过氧化物酶添加到神经上皮的顶端，发现神经板(胚胎第8天)存在功能性紧密连接，但神经管(胚胎第9天)没有。与occludin相反，ZO-1是一种紧密连接的外周膜蛋白，从神经板到神经管期表达增加，也局限于外侧神经上皮细胞膜的顶端。这种定位与N-钙粘蛋白的定位一致，N-钙粘附素的表达随着阻滞素的消失而增加。我们认为，神经上皮细胞紧密连接的丧失反映了其上皮性的整体下降，这在神经元产生之前。(C)1996年学术出版社。
Neuroepithelial cells can generate nonepithelial cells, the neurons. Here we have investigated, for chick and mouse embryos, the epithelial character of neuroepithelial cells in the context of neurogenesis by examining the presence of molecular components of tight junctions during the transition from the neural plate to the neural tube. Immunoreactivity for occludin, a transmembrane protein specific to tight junctions, was detected at the apical end of the lateral membrane of neuroepithelial cells throughout the chick neural plate. During neural tube closure, occludin disappeared from all neuroepithelial cells. Correspondingly, the addition of horseradish peroxidase to the apical side of the neuroepithelium by injection into the amniotic cavity of mouse embryos revealed the presence of functional tight junctions in the neural plate (Embryonic Day 8), but not the neural tube (Embryonic Day 9). In contrast to occludin, expression of ZO-1, a peripheral membrane protein of tight junctions, increased from the neural plate to the neural tube stage, also being confined to the apical end of the lateral neuroepithelial cell membrane. This localization coincided with that of N-cadherin, whose expression increased concomitantly with the disappearance of occludin. We propose that the loss of tight junctions from neuroepithelial cells reflects an overall decrease in their epithelial nature, which precedes the generation of neurons. (C) 1996 Academic Press, Inc.