Tenascin during gut development: appearance in the mesenchyme, shift in molecular forms, and dependence on epithelial-mesenchymal interactions.
Tenascin during gut development: appearance in the mesenchyme, shift in molecular forms, and dependence on epithelial-mesenchymal interactions.
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DOI：
10.1083/jcb.107.6.2341
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发表时间：
1988-12
期刊：
影响因子：
--
通讯作者：
Ekblom P
中科院分区：
文献类型：
--
作者：
Aufderheide E;Ekblom P
腱生蛋白是一种细胞外基质蛋白，在胚胎中生长的上皮细胞周围的间充质中表达。因此，我们研究了上皮细胞是否可以刺激胚胎间充质中腱生蛋白的表达。使用来自假定小肠的间充质，因为已知相互的上皮-间充质相互作用对于肠道形态发生是重要的。制备了大鼠抗小鼠腱生蛋白单克隆抗体，并在ELISA中发现其与小鼠腱生蛋白特异性反应。在培养的成纤维细胞的上清液中，抗体沉淀两个肽的先生260和210 kD。在组织提取物的免疫印迹中，其中一种抗体也与这些腱生蛋白链反应。我们发现，在肠道发育的早期阶段，当间充质已经与内胚层的复层上皮接触时，腱生蛋白是不存在的。相反，它出现在间充质时，同质的内胚层上皮分化成异质的吸收上皮。腱生蛋白仍然存在于成人肠道的基质中，靠近不断更新的上皮细胞的迁移途径。当第一次检测到在肠分化，210-kD的组件是占主导地位的，但在出生时的260-kD组件的相对量有所增加。表达数据表明，间充质中的腱生蛋白的外观依赖于上皮的存在。为了测试这一点，分离的肠间充质细胞从13天的小鼠胚胎培养24小时，无论是单独或与上皮细胞和非上皮细胞。而间充质单独培养或在非上皮B16-F1黑色素瘤细胞的存在下只产生微量的腱生蛋白，表达强烈刺激的上皮细胞系，Madin-Darby犬肾（MDCK）。我们认为，生长和分化的上皮细胞产生局部活性因子，刺激周围间充质中生腱蛋白的合成。
Tenascin, an extracellular matrix protein, is expressed in the mesenchyme around growing epithelia in the embryo. We therefore investigated whether epithelial cells can stimulate expression of tenascin in embryonic mesenchyme. Mesenchyme from the presumptive small intestine was used because it is known that reciprocal epithelial- mesenchymal interactions are important for gut morphogenesis. Rat monoclonal antibodies against mouse tenascin were raised and were found to react specifically with mouse tenascin in ELISA. In supernatants of cultured fibroblasts, the antibodies precipitated two peptides of Mr 260 and 210 kD. One of the antibodies also reacted with these tenascin chains in immunoblots of tissue extracts. We found that tenascin was absent during early stages of gut development, at stages when the mesenchyme is already in contact with the stratified epithelium of the endoderm. Rather, it appeared in the mesenchyme when the homogenous endodermal epithelium differentiated into the heterogenous absorptive epithelium. Tenascin remained present in the stroma of the adult gut, close to the migration pathways of the continuously renewing epithelium. When first detected during intestinal differentiation, the 210-kD component was predominant but at birth the relative amount of the 260-kD component had increased. The expression data suggested that the appearance of tenascin in the mesenchyme was dependent on the presence of epithelium. To test this, isolated gut mesenchymes from 13- d-old mouse embryos were cultured for 24 h either alone or together with epithelial and nonepithelial cells. Whereas mesenchyme cultured alone or in the presence of nonepithelial B16-F1 melanoma cells produced only trace amounts of tenascin, expression was strongly stimulated by the epithelial cell line, Madin-Darby canine kidney (MDCK). We propose that growing and differentiating epithelia produce locally active factors which stimulate synthesis of tenascin in the surrounding mesenchyme.