成人睫状体-视网膜区域神经巢蛋白阳性细胞的分布特征

Experimental studies on the existence and distribution characteristics of neural stem cells in adult human ciliary body and retina

目的探讨成人眼睫状体-视网膜区域神经巢蛋白nestin阳性细胞的分布特征。方法由广东省眼库提供8只新鲜瘁死的健康成人眼球和3只婴儿眼球，分别采用免疫组织化学、逆转录聚合酶链反应（RT-PCR）等方法检测神经干细胞特异性抗原神经巢蛋白nestin在睫状体、视网膜中的表达，通过透射电镜观察其超微结构和分布特点。结果睫状体、视网膜中均有少量nestin阳性细胞表达，其散在分布于睫状体色素上皮层和视网膜内核层靠近外核层的一侧；RT-PCR检测到睫状体、视网膜中均有nestin基因mRNA的表达，睫状体中的表达量高于视网膜区域；透射电镜观察可见睫状体和视网膜组织中均存在一些核大而圆、核仁明显、细胞器较幼稚的具有神经干细胞特征的细胞，位于睫状体色素上皮靠近基底膜的区域及视网膜内核层与外核层之间。结论成人睫状体-视网膜中存在一些具有神经干细胞特征的神经巢蛋白nestin阳性细胞，主要分布于睫状体色素上皮层和视网膜内核层。

Objective To investigate the existence and distribution characteristics of neural stem ceils in the eyes of adult human ciliary body and retina. Methods Eight eyes from 20-40 years old health adult and 3 infant eyes were obtained from Guangdong Eye Bank and were used in the present studies. The protein and mRNA expressions of neural progenitor cell-specific antigen nestin in the ciliary body and retina were detected by immunohistochemical staining and reverse RT-PCR assays, respectively. The ultrastructural and distribution characteristics of these cells were studied by transmission electron microscopy （TEM）. Rusults Immunohistechemical staining showed that there were a few nestin-positive cells existed in pigment epithelium layer of ciliary body and inner nuclear layer （INL） of retina, mRNA expression of nestin gene was detected in both the ciliary body and retina of the infant and adult eyes by RT-PCR assays. The expression of nestin in the infant ciliary body was higher than that of the adult eye. By TEM, a few cells with the characteristic morphology of neural stem cells were identified and their location was consistent with the results of immunohistochemical staining. Conclusion Cells with the features of neural stem cells are present in the pigment epithelium layer of ciliary body and the inner nuclear layer of retina in adult human eyes.