Inatani M, Tanihara H, Oohira A, Honjo M, Honda Y
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Japan.
Invest Ophthalmol Vis Sci. 1999 Sep;40(10):2350-9.
To identify the expression of neurocan, a nervous tissue-specific chondroitin sulfate proteoglycan, in retina and to elucidate its changes during development.
Expressional changes of neurocan mRNAs in developing rat retinas were investigated by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). The localization and characterization of neurocan core proteins were also investigated with the use of Western blot analysis and immunohistochemistry.
Gene expression of neurocan was identified in retinas by RT-PCR. Semiquantitative analysis using Southern blot analysis revealed that mRNA expression for neurocan increased at increasing postnatal stages and that it reached its peak around postnatal day 7 (P7). Immunohistochemical studies demonstrated that in differentiating rat retinal (neuroblast) cells weak neurocan immunoreactivities were observed throughout the retina on embryonal days 14 (E14) and E16. During the early postnatal period, the immunoreactivities became most conspicuous in the inner and outer plexiform layers on P7 through P14. In adult retinas, only faint immunostaining was detected. Immunoblot analysis showed two positive bands of 220- and 150-kDa core glycoproteins after treatment with chondroitinase ABC. Further immunoblot analysis revealed that the expression of these two immunolabeled variants was regulated differently during retinal development.
The temporal and spatial regulation of expression of neurocan and its proteolytic variant during retinal development suggest that it may play a role in differentiation and neural network formation.
鉴定神经黏蛋白（一种神经组织特异性硫酸软骨素蛋白聚糖）在视网膜中的表达，并阐明其在发育过程中的变化。
采用半定量逆转录聚合酶链反应（RT-PCR）研究发育中大鼠视网膜中神经黏蛋白mRNA的表达变化。还通过蛋白质印迹分析和免疫组织化学研究了神经黏蛋白核心蛋白的定位和特征。
通过RT-PCR在视网膜中鉴定出神经黏蛋白的基因表达。使用Southern印迹分析进行的半定量分析显示，神经黏蛋白的mRNA表达在出生后阶段增加，并在出生后第7天（P7）左右达到峰值。免疫组织化学研究表明，在分化的大鼠视网膜（成神经细胞）中，在胚胎第14天（E14）和E16时，整个视网膜均观察到较弱的神经黏蛋白免疫反应性。在出生后早期，免疫反应性在P7至P14期间在内、外丛状层最为明显。在成年视网膜中，仅检测到微弱的免疫染色。蛋白质印迹分析显示，用硫酸软骨素酶ABC处理后，有两条220 kDa和150 kDa核心糖蛋白的阳性条带。进一步的蛋白质印迹分析表明，这两种免疫标记变体的表达在视网膜发育过程中受到不同的调节。
神经黏蛋白及其蛋白水解变体在视网膜发育过程中的表达在时间和空间上的调节表明，它可能在分化和神经网络形成中起作用。
