Prime S S, Toh B H
J Cell Sci. 1978 Oct;33:329-40. doi: 10.1242/jcs.33.1.329.
The distribution of concanavalin A (Con A) surface receptors and cytoplasmic actin in the same cell was studied in monolayer cultures of 2 odontogenic epithelial cells of different developmental age and in ecto-mesenchymal cells derived from the same tooth germ. Con A receptors were demonstrated by fluorescein-isothiocyanate-labelled Con A (FITC-Con A) and cytoplasmic actin by a specific anti-actin autoantibody (AAA) traced with a rhodamine-labelled goat anti-human globulin (R-AHG). All 3 cell types, incubated with FITC-Con A at 37 degrees C for increasing time periods, showed progressive changes in staining patterns from clusters, caps to perinuclear globules. Capping was seen in the majority of immature epithelial cells at 120--180 min, in cells of more mature epithelium at 180--240 min and in ecto-mesenchymal cells at 240--360 min. Binding of FITC-Con A to cell surfaces resulted in sequential changes in AAA staining from filamentous to an aggregated or diffuse pattern, co-capping of aggregated or diffusely stained areas with those capped by FITC-Con A, presence of aggregated or diffusely stained areas in sites similar to the perinuclear globules stained by FITC-Con A, to final re-emergence of filamentous staining. Prior treatment of cells with cytochalasin B or colchicine promoted capping in epithelial but not in ecto-mesenchymal cells while presence of either drug throughout the staining procedure inhibited capping. The results show that Con A receptors are more mobile in epithelial compared to ecto-mesenchymal cells and in immature epithelial cells compared to their more mature counterparts, and that binding and mobility of Con A receptors on the cell surface is associated with redistribution of cytoplasmic actin. The cytochalasin B and colchicine experiments suggest that both microfilaments and microtubules may have synergistic roles in the opposing functions of receptor anchorage and mobility, and that the relative receptor immobility of ectomesenchymal compared to epithelial cells may be attributed to firmer receptor anchorage to the cytoskeleton.
在不同发育阶段的两种牙源性上皮细胞以及源自同一牙胚的外间充质细胞的单层培养物中，研究了同一细胞中伴刀豆球蛋白A（Con A）表面受体和细胞质肌动蛋白的分布情况。用异硫氰酸荧光素标记的Con A（FITC-Con A）显示Con A受体，并用罗丹明标记的山羊抗人球蛋白（R-AHG）追踪的特异性抗肌动蛋白自身抗体（AAA）显示细胞质肌动蛋白。所有这三种细胞类型在37℃下与FITC-Con A孵育不同时间段后，染色模式呈现出从簇状、帽状到核周小球状的逐渐变化。在120 - 180分钟时，大多数未成熟上皮细胞出现帽状；在180 - 240分钟时，较成熟上皮细胞出现帽状；在240 - 360分钟时，外间充质细胞出现帽状。FITC-Con A与细胞表面结合导致AAA染色从丝状依次变为聚集或弥散模式，聚集或弥散染色区域与FITC-Con A帽状区域共帽状，在类似于FITC-Con A染色的核周小球的部位出现聚集或弥散染色区域，最终丝状染色再次出现。用细胞松弛素B或秋水仙碱预先处理细胞促进上皮细胞而非外间充质细胞的帽状形成，而在整个染色过程中存在任何一种药物都会抑制帽状形成。结果表明，与外间充质细胞相比，上皮细胞中的Con A受体更具流动性；与较成熟的上皮细胞相比，未成熟上皮细胞中的Con A受体更具流动性，并且细胞表面Con A受体的结合和流动性与细胞质肌动蛋白的重新分布相关。细胞松弛素B和秋水仙碱实验表明，微丝和微管在受体锚定和流动性的相反功能中可能具有协同作用，并且外间充质细胞与上皮细胞相比相对受体固定性可能归因于受体与细胞骨架的更牢固锚定。
