晶状体上皮细胞转分化对老年性白内障形成的影响研究

The effect of lens epithelial cell transdifferentiation on the senile cataract formation

目的 :为研究晶状体上皮细胞转分化对老年性白内障形成的影响。方法 :对 14例老年性白内障晶状体前囊上皮细胞进行角质蛋白 -8、波形纤维蛋白和纤维粘连蛋白表达的免疫组化研究。结果 :皮质性白内障晶状体上皮的波形纤维蛋白表达明显强于核性白内障 (P <0 0 5 ) ;角质蛋白 -8在皮质性白内障晶状体上皮的表达比核性白内障弱 ((P <0 0 1) ;纤维粘连蛋白在皮质性白内障晶状体上皮的表达明显强于核性白内障 ,而在正常晶状体上皮不表达。结论 :晶状体上皮细胞具有转分化为成纤维样细胞的双向化潜能。晶状体上皮获得转分化能力后而失去原来的细胞学特性。在老年皮质性白内障中 ,晶状体上皮细胞转分化成为成纤维样细胞 ,伴随波形纤维蛋白的过度表达和角质蛋白表达下降。同时合成包括纤维粘连蛋白在内的细胞外基质增多 ,而纤维粘连蛋白能促进晶状体上皮的增殖、迁移及粘附 ,因而晶状体上皮细胞转分化对老年性白内障形成及后囊混浊的形成发挥重要作用。

Objective:To investigate the effect of lens epithelial cells transdifferentiation on the senile cataract formation.Methods:Using the technique of immunohistochemistry cytokeratin -8,vimentin and fibronectin were examined in the lens epithelial cells of senile cataract of 14 patients.Result:The express of vimentin in the lens epithelial cells of cortical cataract was significantly higher than that of nuclear cataract and normal lens(P<0.05).The express of cytokeratin -8 in the lens epithelial of cortical cataract were significantly lower than that of nuclear cataract and normal lens(P<0.01).Fibronectin was not expressed in the capsule of normal lens,but it was significantly highly expressed in the capsule of cortical cataract than that in the capsule of nuclear cataract.Conclusion:The lens epithelial cells(LECs)possess a bipotential nature with the ability to transdifferentiate into fibroblast-like cells.Transdifferentiated LECs in cortical cataract acquired their mesenchymal nature while losing the characteristics of epithelial cells,so the express of vimentin increases but that of cytokeratin -8 decreases in LECs of cortical cataract.At the same time,the transdifferentiated LECs in cortical cataract produce more extracellular matrixes including fibronectin,which can promote cell attachment,proliferation and migration of LECs and play an important role in the formation of senile cataract and posterior capsule opacification.