【摘要】 目的探讨兔角膜缘干细胞(limbal stem cells,LSCs)的形态学特征、数量及分布。方法健康成年新西兰大耳兔30只,体质量2.0～2.5kg,雌雄不分,取双侧眼球,常规石蜡切片,HE染色及免疫组化p63染色显示角膜缘一般特征及LSCs的分布,并用BioMias图像分析软件对LSCs进行计数。另外取3只兔眼角膜缘制作超薄切片,透射电镜观察。结果①角膜缘上皮细胞排列紧密,层数较多,基底层细胞呈矮柱状或立方形,核大而圆,位于细胞中央,着色较深。LSCs(p63阳性细胞)呈矮柱状或立方形,多位于角膜缘上皮基底层,在角膜缘浅层及角膜边缘有少量分布,在角膜中央上皮未见LSCs出现。②透射电镜观察LSCs核较大,形状不规则,核内常染色质较多,异染色质散在分布,未凝集成块。细胞质少,含较丰富的游离核糖体,其他细胞器少,细胞间可见较多的缝隙连接。③图像分析显示高倍镜视野下角膜缘上皮LSCs数量为(35.25±8.93)个。结论①LSCs具有原始细胞的超微结构特征,与其他干细胞形态相似。②LSCs主要位于角膜缘上皮基底层,在角膜缘浅层上皮及角膜边缘上皮内也有少量LSCs存在,在中央角膜上皮未见LSCs分布。更多还原

【Abstract】 Objective To investigate the morphological characteristics,quantity and distribution of rabbit limbal stem cells (LSCs). Methods Bilateral eyes of 30 healthy adult New Zealand rabbits weighing 2.0-2.5 kg were enucleated and handled by paraffin sections. The morphological characteristic of the limbus of the cornea was observed after Hematoxylin-Eosin staining. LSCs were detected and observed by immunohistochemistry technique (p63-staining) and electron microscopy. The p63-positive LSCs were counted by the BioMias software of image analysis. Results ① The limbal epithelial cells were closely aggregated and the layers of the cells were more than the central zone of the cornea. The cells of the basal layer were low columnar or cubic shape and their nuclei were centrally positioned and stained darker blue. The p63-positive LSCs appeared low columnar or cubic shape. Many p63-positive LSCs were located in the bottom of the limbal epithelium. There were a few of p63-positive LSCs in the superficial limbal and the edge of the corneal epithelium,but not in the central corneal epithelium. ② LSCs displayed the ultrastructural features of the primitive cells by transmission electron microscopy. The large nuclei were irregular in shape. Much euchromatin but less heterochromatin could be seen in the nuclei. The heterochromatin was scattered instead of condensation into pieces. Abundant ribosomes could be seen in the little cytoplasm. Other organelles were rarely found. Many gap junctions were seen between the adjacent cells. ③ There were 35.25±8.93 LSCs in the limbal epithelium of each view under high power microscope by analysis with Biomiaspro photo-analysis software. Conclusion LSCs show the ultrastructural characteristics of the primitive cells,similar to other stem cells. LSCs are mainly seen in the bottom of the limbal epithelium. A few of LSCs could be seen in the superficial limbal epithelium,but not in the central corneal epithelium.更多还原