目的 研究波形纤维蛋白在人胚胎视网膜发育过程中表达的动态变化。方法 收集25例8~39孕周胎龄的胎儿眼球标本,5例正常成人眼球标本。冰冻连续切片,波形纤维蛋白抗体孵育,普通光镜及激光共聚焦显微镜观察视网膜。结果 25~28周波形纤维蛋白在人胚视网膜Müller细胞上的表达上调。25周在视网膜神经节细胞层、内丛状层和内核层出现了长丝状阳性表达;28周附着于内界膜的锥状突起在神经节细胞层部位,与长丝状的阳性表达突起交错排列。部分阳性突起由附着点的内界膜直达外界膜,贯穿视网膜大部分区域,外界膜亦呈阳性反应。结论 波形纤维蛋白为观察Müller细胞在视网膜发育过程中分化和迁移的一个良好标记物。人视网膜Müller细胞基本发育成熟的时间为胚胎25~28周。
Objective Studies have demonstrated that anti-vimentin predominantly labels retinal astrocytes and MUller cell foot processes in normal adult and fetal retina. This study was to evaluate the disparity of expression of Vimentin(VIM) in human fetal retina. Methods Twenty-five human fetal eyes aged 8-39 weeks of gestation (WG) and 5 eyes of normal donors were collected. Frozen sections were immunohistochemically stained with antibody to VIM. Specimens were evaluated by light and laser scanning confocal microscope. Results VIM-immunoreactive staining was detected in the cytoplasm and foot processes with brown yellow color in immunohistochemistry and green flourescencs in immunofluoreseence, Positive immunostaining for VIM was detected in neuroblastic layer at fetal eyes of 8 WG,and columnar processes could be seen at a part of the cells in ganglion cell layer(GCL) at 15 WG. The structure of inner limiting membrane(ILM) was morphologically clear at 19 WG. A upregulation of VIM in MUller cell was observed during 25 WG to 28 WG, and at 25 WG, the long threadlike positive immunostainings were present in GCL,inner plexiform layer(IPL) and inner nuclear layer(INL). In fetal eyes of 28 WG, the pyramidal processes inserted to ILM were overlapped with those long threadlike positive immunostainings in GCL, and some VIM labeling processes crossed the most retina from ILM up to outer limiting membrane(OLM). Conclusion VIM is a good marker in the research of differentiation and migration of Mtiller cell in human fetal retina. During 25 WG to 28 WG, retinal Mtiller cell of human fetal eye is fundamentally mature. Laser scanning confocal microscope provides a more detailed view of the fetal retina morphology and gives any focal plane of interest with less interferes about image resolution.