Reactivation of intestinal epithelial cell brush border motility: ATP-dependent contraction via a terminal web contractile ring.
Reactivation of intestinal epithelial cell brush border motility: ATP-dependent contraction via a terminal web contractile ring.
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肠上皮细胞刷边界运动的重新激活：通过末端Web收缩环的ATP依赖性收缩。
DOI：
10.1083/jcb.95.3.853
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发表时间：
1982-12
期刊：
影响因子：
--
通讯作者：
Burgess DR
中科院分区：
文献类型：
--
作者：
Burgess DR
已经提出了各种模型，表明肠上皮细胞的刷状缘可能是能动的。实验记录假定的刷状缘运动已经进行了隔离刷状缘，并产生了模型，表明微绒毛收缩或微绒毛根相互作用。报道的Ca++ ATP诱导的微绒毛收缩已被证明是微绒毛溶解对Ca++的反应，而不是主动的刷状缘运动。我在这里报告的研究重新激活的运动在完整的片离体肠上皮细胞。将整个上皮片甘油化，使刷状缘和细胞间连接保持完整，然后用ATP、PPi、ITP、ADP、GTP或δ S-ATP处理。通过视频增强微分干涉对比显微镜和薄切片透射电子显微镜分析显示，收缩在终端网络区域导致微绒毛被扇除了响应ATP和δ S-ATP，但不响应ADP，PPi，ITP，或GTP。电子显微镜显示，收缩发生在中间连接的水平，在一个圆周收缩，可以拉细胞完全分开。这种收缩发生在由含有肌动蛋白的细丝环带占据的位置，如S-1结合所证明的，其在中间连接水平完全包围末端网。在收缩时，这条带变得更密集和更厚。由于肌球蛋白，α-辅肌动蛋白和原肌球蛋白，除了肌动蛋白，已被本地化到这个地区的终端网络，它建议肠上皮细胞可以通过一个圆周终端网络收缩环类似于收缩环的分裂细胞的运动。
Various models have been put forward suggesting ways in which brush borders from intestinal epithelial cells may be motile. Experiments documenting putative brush border motility have been performed on isolated brush borders and have generated models suggesting microvillar retraction or microvillar rootlet interactions. The reported Ca++ ATP- induced retraction of microvilli has been shown, instead, to be microvillar dissolution in response to Ca++ and not active brush border motility. I report here studies on the reactivation of motility in intact sheets of isolated intestinal epithelium. Whole epithelial sheets were glycerinated, which leaves the brush border and intercellular junctions intact, and then treated with ATP, PPi, ITP, ADP, GTP, or delta S-ATP. Analysis by video enhanced differential interference-contrast microscopy and thin-section transmission electron microscopy reveals contractions in the terminal web region causing microvilli to be fanned apart in response to ATP and delta S-ATP but not in response to ADP, PPi, ITP, or GTP. Electron microscopy reveals that the contractions occur at the level of the intermediate junction in a circumferential constriction which can pull cells completely apart. This constriction occurs in a location occupied by an actin- containing circumferential band of filaments, as demonstrated by S-1 binding, which completely encircles the terminal web at the level of the intermediate junction. Upon contraction, this band becomes denser and thicker. Since myosin, alpha-actinin and tropomyosin, in addition to actin, have been localized to this region of the terminal web, it is proposed that the intestinal epithelial cell can be motile via a circumferential terminal web contractile ring analogous to the contractile ring of dividing cells.