细胞周期依赖性激酶抑制剂P27,P21在人角膜上皮的表达研究

目的:探讨细胞周期依赖性激酶抑制剂(CKI)P27,P21 在角膜上皮细胞的表达情况。方法:应用 SP 免疫组化法,检测 P21,P27 等细胞周期依赖性激酶抑制剂和增殖细胞核抗原(PCNA)在角膜上皮不同部位的表达情况。结果:角膜缘上皮区 PCNA 呈阳性表达,主要位于基底细胞层,中央区角膜上皮内未见阳性表达,差异有显著意义(P <0.01);P27,P21 在中央区角膜上皮内呈阳性表达,角膜缘上皮内未见阳性表达,差异均有显著意义(P <0.01)。结论:细胞周期依赖性激酶抑制剂 P27,P21 和 PCNA 在角膜上皮不同部位的表达差异,提示在角膜缘上皮基底层内存在着一群有较高的增殖能力,处于 G1 期的细胞群,即干细胞。

Cyclin dependent kinase inhibitor P27, P21 expressions in human corneal epithelium

AIM: To investigate the expressions of the cyclin dependent kinase inhibitor (CKI) in human corneal epithelium.METHODS: The expressions of CKI, P27, P21 and proliferating cell nuclear antigen (PCNA) were tested in different regions of corneal epithelium by SP immunohistochemistry.RESULTS: Limbal basal cells stained positively for PCNA while central corneal epithelium cells stained negatively for PCNA, their difference was statistically significant (P＜0.01).Positive staining for P27 and P21 were observed in central epithelium, but there was no positive staining in limbal epithelium. Their difference were also statistically significant (P＜0.01).CONCLUSION: The different expressions of CKI P27, P21and PCNA in different corneal epithelial regions suggest that in limbal basal layer there are a group of cells that have higher proliferative capacity staying in G1 status, namely stem cell.