方法：体外培养hRPE细胞，以60mmol/L的葡萄糖建立高糖模型，实验分对照组(5.5mmol/L的葡萄糖)和高糖24，48，72h组，用免疫组织化学法及Real-time PCR技术检测各组RPE细胞N-cadherin和fibronectin的表达。

结果：高糖组RPE细胞出现排列紊乱，胞体变长变大，高糖72h组最明显。免疫组织化学法检测结果显示：与对照组相比，高糖组RPE细胞N-cadherin表达呈下降趋势； 而fibronectin表达出现并呈升高趋势。Real-time PCR检测结果显示：与对照组相比，高糖组RPE细胞N-cadherin mRNA表达水平在24h时出现下降，72h时降低最明显(F=12.252，P=0.000)，24h组与对照组相比差异无统计学意义，48h及72h组分别与对照组相比差异有统计学意义(P<0.05)； 与对照组相比，高糖组RPE细胞fibronectin mRNA表达水平在24h时出现升高，72h时升高最明显(F=50.543，P=0.000)，24h组与对照组相比差异无统计学意义，48h及72h组fibronectin mRNA表达水平明显升高，分别与对照组相比差异有统计学意义(P=0.000，P=0.000)。

结论：高糖条件下RPE细胞上皮标记物N-cadherin表达下调，间质标记物fibronectin表达出现，发生EMT改变，这一现象为探讨增生性糖尿病视网膜病变的发病机制及其防治提供新的思路。

METHODS: Human RPE(hRPE)cells were cultured in vitro. Containing a final concentration of 60mmol/L glucose was used for high glucose treatment. The cells were divided into normal glucose group(5.5mmol/L, NG)and high glucose group(24, 48 and 72h)respectively. The expression of N-cadherin and fibronectin in hRPE cells were evaluated by immunofluorescence and real-time PCR.

RESULTS:RPE cells became disorganized and swollen over time under high glucose conditions, especially in 72h subgroup. Immunohistochemical analysis revealed that the expression of N-cadherin in RPE cells under high glucose conditions was decreased compared with that in the control group, while the expression of fibronectin was increased. Real-time PCR results showed that the expression of N-cadherin mRNA in high glucose group was decreased at 24h compared with that in the control group, and declined markedly at 72h(F=12.252, P=0.000). There were no significant differences between the control group and the high glucose group at 24h, while the differences between the control group and the high glucose group(48 and 72h)were significant respectively(P<0.05). Meanwhile, the expression of fibronectin mRNA in RPE cells was increased in high glucose group at 24h, and reached the peak at 72h(F=50.543, P=0.000). There were no significant differences between the control group and the high glucose group at 24h. Compared with the control group, the expression of fibronectin mRNA in hRPE cells was increased significantly in high glucose group(48 and 72h)respectively(P=0.000, P=0.000).

CONCLUSION: The expression of epithelium marker N-cadherin is down-regulated under high glucose conditions in hRPE cells in vitro. Meanwhile, the expression of mesenchymal maker fibronectin is induced and appeared to EMT changes. Results of this study will enrich our growing understanding in proliferative diabetic retinopathy and hopefully lead to novel insights for the pathogenesis and therapeutic treatments.