上皮性钙黏附蛋白在人角膜上皮中的表达研究

Expression of E-cadherin in human corneal epithelium

目的研究上皮性钙黏附蛋白(Ecadherin)在人角膜上皮中的分布。方法低钙培养基培养人角膜缘干细胞,并取人角膜中央上皮及角膜边缘上皮组织,分别使用免疫组织化学及免疫细胞化学方法检测Ecadherin在人角膜中央上皮、角膜边缘上皮及低钙培养的人角膜缘干细胞中的分布情况。结果Ecadherin在角膜边缘上皮全层细胞即处于分化阶段的短暂扩充细胞中大量表达,在抑制干细胞分化、促进增殖的低钙培养的人角膜缘干细胞中表达减少,在终末分化细胞即角膜中央上皮细胞中没有表达。结论Ecadherin在处于分化阶段的角膜上皮细胞中有大量的表达。

Objective To analyze the expression of E-eadherin in human corneal epithelium. Methods Twenty-four human corneas were collected from eye bank of Hebei province. The age range of cornea donor were from 21 to 54 years old and the time from donor death to cell culture was less than 12 hours. Low Ca^2＋ culture media was used to culture human limbal stem cells. The cell expression in human central cornea epithelium ,fringe epithelium and cultured limbal stem cells of E-cadherin was observed by immunoeytochemistry and immunohistochemistry. Results Only a few of cells cultured by low Ca^2＋ media could promote proliferation and suppress differentiation and expressed E-cadherin on their cellular membrane. Epithelium, anterior elastical lamina and stroma could be seen by immunocytochemistry. Almost all cell membranes in basal cells, wing cells and superficial cells of fringe epithelium expressed E-cadherin. The cells can be regarded as transient amplifying cells in differentiation stage. There was no apparent expression in cells of central epithelium that can be regarded as terminally differentiated cells. The color of cell expressing E-cadherin was brown. Conclusion A substantial fraction of human corneal epithelium in differentiation stage express E-cadherin.