Glabe C G, Yednock T, Rosen S D
J Cell Sci. 1983 May;61:475-90. doi: 10.1242/jcs.61.1.475.
We have examined the effects of a variety of polysaccharides and glycoconjugates on the organization and morphology of cultured A14CL-1 endothelial monolayers. The sulphated fucose-containing polysaccharides, fucoidin and sea-urchin egg jelly fucan, induce a dramatic disruption of the organization of the monolayers, characterized by the retraction of adjacent borders of cells exposing areas of the subendothelial matrix. This effect, which occurs at a fucoidin concentration of 10 micrograms/ml, is rapidly reversible after the fucoidin-containing medium is removed. Within 1 h after replacement with fresh medium many cell contacts are re-established; within 20 h the fucoidin-treated monolayers closely resemble the untreated controls. The effect of the sulphated fucose-containing polysaccharides is specific. Of a wide variety of sulphated polysaccharides and glycoconjugates tested, only fucoidin and the egg jelly fucan produce a detectable alteration in the morphology of cultured endothelial monolayers. The endothelial monolayer has specific binding sites for fucoidin. The binding of fucoidin is saturable and a maximum of 4.5 X 10(5) molecules of fucoidin are bound per cell with an apparent affinity of 2.3 X 10(-7) M. A significant proportion (26%) of the total monolayer-associated fucoidin is apparently internalized by the endothelial cells after incubation with fucoidin for 1 h at 37 degrees C. The morphological response to fucoidin is probably not due to its internalization, since the effect is observed at 7 degrees C where little uptake (3.5%) occurs. Fucoidin appears to bind at two distinct sites on endothelial monolayers. One site is inhibitable by heparin, while the other site seems to be specific for fucoidin. The observation that fucoidin still induces the retraction of the endothelial cells in the presence of a 100-fold excess of heparin, suggests that binding at the fucoidin-specific site is responsible for the morphological effect of fucoidin. In addition, fucoidin has no detectable effect on monolayers of 3T3 and BHK fibroblast-like cells at 1 mg/ml, 100-fold higher than the concentration required to produce an effect on endothelial cells. Among the possible interpretations of these results is that sulphated fucose-containing glycoconjugates may play a role in the adhesive interactions of endothelial cells.
我们研究了多种多糖和糖缀合物对培养的A14CL-1内皮细胞单层组织和形态的影响。含硫酸化岩藻糖的多糖，即岩藻依聚糖和海胆卵黄囊岩藻聚糖，会引起单层组织的显著破坏，其特征是细胞相邻边界收缩，暴露出内皮下基质区域。这种效应在岩藻依聚糖浓度为10微克/毫升时出现，在去除含岩藻依聚糖的培养基后可迅速逆转。用新鲜培养基替换后1小时内，许多细胞接触得以重新建立；20小时内，经岩藻依聚糖处理的单层细胞与未处理的对照非常相似。含硫酸化岩藻糖的多糖的作用具有特异性。在测试的多种硫酸化多糖和糖缀合物中，只有岩藻依聚糖和卵黄囊岩藻聚糖能使培养的内皮细胞单层形态发生可检测到的改变。内皮细胞单层对岩藻依聚糖有特异性结合位点。岩藻依聚糖的结合是可饱和的，每个细胞最多结合4.5×10⁵个岩藻依聚糖分子，表观亲和力为2.3×10⁻⁷M。在37℃下与岩藻依聚糖孵育1小时后，内皮细胞明显内化了相当比例（26%）的与单层相关的总岩藻依聚糖。对岩藻依聚糖的形态学反应可能不是由于其内化，因为在7℃时观察到这种效应，而此时摄取很少（3.5%）。岩藻依聚糖似乎在内皮细胞单层上的两个不同位点结合。一个位点可被肝素抑制，而另一个位点似乎对岩藻依聚糖具有特异性。在存在100倍过量肝素的情况下，岩藻依聚糖仍能诱导内皮细胞收缩，这一观察结果表明，在岩藻依聚糖特异性位点的结合是岩藻依聚糖形态学效应的原因。此外，在1毫克/毫升时，岩藻依聚糖对3T3和BHK成纤维细胞样细胞单层没有可检测到的影响，该浓度比产生对内皮细胞影响所需的浓度高100倍。这些结果的可能解释之一是，含硫酸化岩藻糖的糖缀合物可能在内皮细胞的粘附相互作用中起作用。
