Kobayashi S, Vidal I, Pena J D, Hernandez M R
Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Glia. 1997 Jul;20(3):262-73. doi: 10.1002/(sici)1098-1136(199707)20:3<262::aid-glia10>3.0.co;2-s.
The human optic nerve contains a heterogeneous population of astrocytes. In situ, a specialized subpopulation of astrocytes was distinguished in the adult optic nerve head by expression of neural cell adhesion molecule (NCAM). To further study the biology of astrocytes, we have developed and characterized cells grown from explanted optic nerve heads and myelinated optic nerves as in vitro model systems. Second or third passage cells were processed for immunocytochemistry using antibodies against glial fibrillary acidic protein (GFAP) and cell surface epitopes: CD56/NCAM, HNK-1/NCAM, A2B5, and O4. Synthesis and gene expression of NCAM were characterized by Western blot analysis and RNase protection assay. Cells grown from myelinated optic nerves expressing GFAP, but not NCAM or A2B5, were identified as type 1A astrocytes, and cells expressing GFAP and A2B5, but not NCAM, were identified as type 2 astrocytes. Cells grown from explanted optic nerve head expressing GFAP, NCAM, and O4 were identified as type 1B astrocytes. Expression of NCAM by type 1B astrocytes may provide these cells with adhesion properties that allow them specialized responses in their microenvironment. Astrocytes from the lamina cribrosa may form a functional barrier to prevent myelination of the retina. In glaucoma, these astrocytes may be exposed to stresses due to fluctuation in intraocular pressure and therefore participate in the optic nerve changes associated with glaucomatous optic neuropathy.
人类视神经包含多种不同类型的星形胶质细胞。在原位，成年视神经乳头中通过神经细胞黏附分子（NCAM）的表达区分出一类特殊的星形胶质细胞亚群。为了进一步研究星形胶质细胞的生物学特性，我们开发并鉴定了从视神经乳头和有髓鞘的视神经外植体生长而来的细胞，作为体外模型系统。使用针对胶质纤维酸性蛋白（GFAP）和细胞表面表位的抗体对第二代或第三代传代细胞进行免疫细胞化学处理：CD56/NCAM、HNK-1/NCAM、A2B5和O4。通过蛋白质印迹分析和核糖核酸酶保护试验对NCAM的合成和基因表达进行了表征。从表达GFAP但不表达NCAM或A2B5的有髓鞘视神经生长而来的细胞被鉴定为1A型星形胶质细胞，而表达GFAP和A2B5但不表达NCAM的细胞被鉴定为2型星形胶质细胞。从表达GFAP、NCAM和O4的视神经乳头外植体生长而来的细胞被鉴定为1B型星形胶质细胞。1B型星形胶质细胞表达NCAM可能赋予这些细胞黏附特性，使其能够在微环境中产生特殊反应。筛板处的星形胶质细胞可能形成功能性屏障以防止视网膜发生髓鞘形成。在青光眼中，这些星形胶质细胞可能因眼内压波动而受到压力，因此参与与青光眼性视神经病变相关的视神经变化。
