Trautman M S, Kimelman J, Bernfield M
Department of Pediatrics, Stanford Medical Center, CA 94305.
Development. 1991 Jan;111(1):213-20. doi: 10.1242/dev.111.1.213.
Syndecan is an integral membrane proteoglycan that behaves as a matrix receptor by binding cells to interstitial matrix and associating intracellularly with the actin cytoskeleton. Using immunohistology, we have now localized this proteoglycan during the morphogenesis of various derivatives of the surface ectoderm in mouse embryos. Syndecan is expressed on ectodermal epithelia, but is selectively lost from the cells that differentiate into the localized placodes that initiate lens, nasal, otic and vibrissal development. The loss is transient on presumptive ear, nasal and vibrissal epithelia; the derivatives of the differentiating ectodermal cells that have lost syndecan subsequently re-express syndecan. In contrast, syndecan is initially absent from the mesenchyme underlying the surface ectoderm, and is transiently expressed when the surface ectoderm loses syndecan. These results demonstrate that expression of syndecan is developmentally regulated in a distinct spatiotemporal pattern. On epithelia, syndecan is lost at a time and, location that correlates with epithelial cell differentiation and, on mesenchyme, syndecan is acquired when the cells aggregate in proximity to the epithelium. This pattern of change with morphogenetic events is unique and not duplicated by other matrix molecules or adhesion receptors.
Syndecan是一种整合膜蛋白聚糖，它通过将细胞与细胞间质基质结合并在细胞内与肌动蛋白细胞骨架相关联，从而发挥基质受体的作用。利用免疫组织学方法，我们现已在小鼠胚胎表面外胚层的各种衍生物的形态发生过程中对这种蛋白聚糖进行了定位。Syndecan在外胚层上皮细胞上表达，但在分化为启动晶状体、鼻、耳和触须发育的局部基板的细胞中选择性丢失。在假定的耳、鼻和触须上皮细胞上，这种丢失是短暂的；已经丢失Syndecan的分化外胚层细胞的衍生物随后会重新表达Syndecan。相比之下，Syndecan最初在表面外胚层下方的间充质中不存在，当表面外胚层丢失Syndecan时，它会短暂表达。这些结果表明，Syndecan的表达在发育过程中受到独特的时空模式调控。在上皮细胞上，Syndecan在与上皮细胞分化相关的时间和位置丢失，而在间充质上，当细胞在靠近上皮细胞处聚集时获得Syndecan。这种随形态发生事件的变化模式是独特的，其他基质分子或黏附受体不会重复这种模式。
