Margolis R K, Goossen B, Tekotte H, Hilgenberg L, Margolis R U
Department of Pharmacology, State University of New York, Brooklyn 11203.
J Cell Sci. 1991 Jun;99 ( Pt 2):237-46. doi: 10.1242/jcs.99.2.237.
We have examined the effects of beta-xylosides, which act as exogenous acceptors for glycosaminoglycan chain initiation, on the morphology and proteoglycan biosynthesis of PC12 pheochromocytoma cells, and on monolayer, aggregate and explant cultures of early postnatal rat cerebellum. PC12 cells cultured for 13 days in the presence of nerve growth factor (NGF) and beta-xyloside, and labeled during days 11-13 with sodium [35S]sulfate, showed an 8- to 11-fold increase in [35S]sulfate-labeled macromolecules released into the culture medium. Most of the increase was accounted for by chondroitin sulfate, which was in the form of free glycosaminoglycan chains, which were not acid-precipitable. The presence of beta-xyloside also led to a 65-115% increase in [35S]sulfate incorporation into cell-associated glycosaminoglycans and glycoproteins of untreated and NGF-treated PC12 cells, respectively. beta-Xyloside treatment reduced the size of the chondroitin sulfate chains in both the cells and medium from approximately 34,000 to 10,000 Mr, but had much less effect on heparan sulfate, which decreased in size from 16,000 to 13,000-14,500 Mr (in the medium and cells, respectively). beta-Xyloside inhibition of proteoglycan biosynthesis was accompanied by significant morphological effects in NGF-treated PC12 cells, consisting of an increase in length and decrease in the branching, diameter and adhesion to the collagen substratum of the PC12 cell processes. p-Nitrophenyl- and 4-methylumbelliferyl-beta-D-xylosides produced similar effects, which were not seen with p-nitrophenyl-beta-D-galactoside. beta-Xylosides also produced distinct alterations in the adhesion and morphology of monolayer, aggregate, and explant cultures of early postnatal rat cerebellum, which occurred together with inhibition of chondroitin sulfate proteoglycan biosynthesis and a decrease in glycosaminoglycan chain size. These studies indicate that chondroitin sulfate (and probably also heparan sulfate) proteoglycans play a significant role in modulating cell-cell and cell-matrix interactions in nervous tissue development and differentiation.
我们研究了作为糖胺聚糖链起始的外源性受体的β-木糖苷，对PC12嗜铬细胞瘤细胞的形态和蛋白聚糖生物合成，以及对新生大鼠小脑早期单层、聚集体和外植体培养物的影响。在神经生长因子（NGF）和β-木糖苷存在的情况下培养13天的PC12细胞，并在第11 - 13天用[35S]硫酸钠标记，结果显示释放到培养基中的[35S]硫酸盐标记的大分子增加了8至11倍。增加的大部分是由硫酸软骨素引起的，其呈游离糖胺聚糖链的形式，不能被酸沉淀。β-木糖苷的存在还分别导致未处理的和NGF处理的PC12细胞中与细胞相关的糖胺聚糖和糖蛋白中[35S]硫酸盐掺入量增加65 - 115%。β-木糖苷处理使细胞和培养基中硫酸软骨素链的大小从约34,000 Mr减小到10,000 Mr，但对硫酸乙酰肝素的影响小得多，其大小分别从16,000 Mr减小到13,000 - 14,500 Mr（分别在培养基和细胞中）。β-木糖苷对蛋白聚糖生物合成的抑制伴随着在NGF处理的PC12细胞中的显著形态学效应，包括PC12细胞突起的长度增加以及分支、直径和对胶原基质的粘附减少。对硝基苯基-β-D-木糖苷和4-甲基伞形酮基-β-D-木糖苷产生类似的效应，而对硝基苯基-β-D-半乳糖苷则未观察到这种效应。β-木糖苷还使新生大鼠小脑早期单层、聚集体和外植体培养物的粘附和形态发生明显改变，并伴随硫酸软骨素蛋白聚糖生物合成的抑制和糖胺聚糖链大小的减小。这些研究表明硫酸软骨素（可能还有硫酸乙酰肝素）蛋白聚糖在神经组织发育和分化过程中调节细胞-细胞和细胞-基质相互作用中起重要作用。
