Proteoglycan synthesis in flat cell-free cultures of chick embryo retinal neurons and photoreceptors.
Proteoglycan synthesis in flat cell-free cultures of chick embryo retinal neurons and photoreceptors.
复制标题
鸡胚视网膜神经元和光感受器的扁平无细胞培养物中蛋白多糖的合成。
DOI：
10.1016/0012-1606(88)90140-6
复制
发表时间：
1988
影响因子：
2.7
通讯作者：
Hewitt,AT
中科院分区：
文献类型：
--
作者：
Needham,LK;Adler,R;Hewitt,AT
细胞外基质和细胞表面蛋白多糖被认为在神经发育和再生中起重要作用。中枢神经系统蛋白聚糖已从大鼠和绵羊脑以及鸡的神经视网膜中分离和表征。后一种组织提供的实验优势是它是无血管的，并且可以分离出无结缔组织和色素上皮。因此，由该组织合成的蛋白聚糖完全来自神经细胞。然而，尚未确定神经元和光感受器是否有助于蛋白聚糖的合成，或者这些分子是否主要来源于神经胶质。在本研究中，我们已经解决了这个问题，使用鸡视网膜神经细胞培养的扁平，胶质样细胞。用[35 S]硫酸盐和[3 H]氨基葡萄糖作为前体，在体外对视网膜神经元、光感受器和8天鸡胚视网膜未分化、无突起圆形细胞合成的蛋白聚糖进行代谢标记。放射性标记的蛋白多糖积累在培养基中，也可以提取从细胞层通过连续处理与Triton X-100和盐酸胍。通过离子交换色谱法分离蛋白多糖，并通过凝胶过滤色谱法和通过酶和化学处理降解的敏感性进行表征。总的来说，硫酸乙酰肝素蛋白多糖是在这个发育阶段培养的神经视网膜细胞体外合成的主要蛋白多糖类型。培养基和Triton提取物含有不同比例的硫酸软骨素和硫酸乙酰肝素蛋白聚糖，而硫酸乙酰肝素是从胍提取物中回收的唯一蛋白聚糖。这些研究表明，硫酸乙酰肝素和硫酸软骨素蛋白聚糖是由不含扁平神经胶质样细胞的神经视网膜细胞培养物主动合成的。
Extracellular matrix and cell surface proteoglycans are thought to play important roles in neural development and regeneration. Central nervous system proteoglycans have been isolated and characterized from rat and sheep brain and from chick neural retina. An experimental advantage offered by the latter tissue is that it is avascular and can be isolated free of connective tissue and pigment epithelium. Therefore, proteoglycans synthesized by this tissue are derived exclusively from neural cells. However, it has not yet been determined whether neurons and photoreceptors contribute to proteoglycan synthesis or whether these molecules are largely glial in origin. In the present study we have addressed this question using cultures of chick neural retinal cells free of flat, glial-like cells. Proteoglycans synthesized by cultures of retinal neurons, photoreceptors, and undifferentiated, process-free round cells from 8-day embryonic chick neural retina were metabolically labeledin vitrousing [35S]sulfate and [3H]glucosamine as precursors. Radiolabeled proteoglycans accumulated in the medium, and could also be extracted from the cell layer by sequential treatments with Triton X-100 and with guanidine HCl. The proteoglycans were isolated by ion-exchange chromatography, and characterized by gel filtration chromatography and by susceptibility to degradation by enzymatic and chemical treatments. Overall, heparan sulfate proteoglycans were the predominant type of proteoglycan synthesizedin vitroby the cultured neural retinal cells at this developmental stage. The medium and the Triton extract contained different proportions of both chondroitin sulfate and heparan sulfate proteoglycans, while heparan sulfate was the only proteoglycan recovered from the guanidine extract. These studies demonstrate that heparan sulfate and chondroitin sulfate proteoglycans are actively synthesized by cultures of neural retinal cells free of flat, glial-like cells.