Tanihara Hidenobu, Inatani Masaru, Koga Takahisa, Yano Tsuyoshi, Kimura Akira
Cornea. 2002 Oct;21(7 Suppl):S62-9. doi: 10.1097/01.ico.0000263121.45898.d2.
Various proteoglycans are expressed in ocular tissues. We investigated and reviewed the distribution and the potential roles of proteoglycans in cornea, trabecular meshwork, and retinal tissues.
Immunohistochemical studies were performed in rat ocular tissues. The concentration of transforming growth factor (TGF)-beta2, which regulates the expression of proteoglycans in aqueous humor from human glaucomatous eyes, was evaluated by enzyme-linked immunosorbent assay (ELISA). In retinal tissues, we examined the localization of 2 soluble nervous tissue-specific chondroitin sulfate proteoglycans, neurocan and phosphacan, by immunohistochemical analysis, then investigated the effect on the neurite outgrowth of cultivated retinal ganglion cells.
The expression of chondroitin sulfate in stroma was upregulated at early postnatal stages and reduced during development in rat eyes. In trabecular meshwork tissues, immunohistochemical studies showed the intense expression of decorin. Moreover, elevated levels of TGF-beta2 in the aqueous humor from glaucomatous patients were observed. In retinal tissues, neurocan and phosphacan were expressed mainly in nerve fiber-rich layers during rat postnatal stages. In vitro, the neurite extension from retinal ganglion cells was inhibited by neurocan and phosphacan.
Soluble extracellular proteoglycans in corneal and trabecular meshwork tissues contribute to the stromal transparency in the corneal tissues and the resistance of the aqueous humor outflow in trabecular meshwork tissues. In retinal tissues, chondroitin sulfate and heparan sulfate proteoglycans are not only secreted into the extracellular space of retinal tissues but also expressed in the membrane of the retinal cells, contributing to the neural network formation and the maintenance of the interphotoreceptor matrix.
多种蛋白聚糖在眼组织中表达。我们研究并综述了蛋白聚糖在角膜、小梁网和视网膜组织中的分布及潜在作用。
对大鼠眼组织进行免疫组织化学研究。通过酶联免疫吸附测定（ELISA）评估调节人青光眼房水中蛋白聚糖表达的转化生长因子（TGF）-β2的浓度。在视网膜组织中，我们通过免疫组织化学分析检测了两种可溶性神经组织特异性硫酸软骨素蛋白聚糖（神经聚糖和磷酸聚糖）的定位，然后研究了其对培养的视网膜神经节细胞神经突生长的影响。
硫酸软骨素在大鼠眼基质中的表达在出生后早期上调，在发育过程中降低。在小梁网组织中，免疫组织化学研究显示核心蛋白聚糖表达强烈。此外，观察到青光眼患者房水中TGF-β2水平升高。在视网膜组织中，神经聚糖和磷酸聚糖在大鼠出生后阶段主要在富含神经纤维的层中表达。在体外，神经聚糖和磷酸聚糖抑制视网膜神经节细胞的神经突延伸。
角膜和小梁网组织中的可溶性细胞外蛋白聚糖有助于角膜组织的基质透明度和小梁网组织中房水流出阻力。在视网膜组织中，硫酸软骨素和硫酸乙酰肝素蛋白聚糖不仅分泌到视网膜组织的细胞外空间，还在视网膜细胞的膜中表达，有助于神经网络形成和光感受器间基质的维持。
