Expression And Significance Of Vimentin And PCNA In The Epithelial Cell Of Lens

Objective: The lens is a transparent,avascular and refraction organ.The lens is composed of epithelial cells and fiber cells. A single layer of epithelial cells covers the anterior surface of the lens and fiber cells occupy the rest of the volume of the lens. The fiber cells form on differentiation of the epithelial cells. During differentiation, lens epithelial cells exit the cell cycle and undergo significant morphologic and biochemical changes that result in the formation of fully differentiated fiber cells, where virtually all organelles, including the nuclei, are removed. This unique pattern of differentiation occurs in the equatorial region of the lens, and fibers with increasingly advanced stages of differentiation accumulate concentrically at the interior of the lens. Proper execution of the differentiation program and formation of mature fibers seem to be required for lens transparency, in that abnormalities that result in incomplete degradation of intracellular organelles are associated with various forms of cataract.To investigate the expression of vimentin and PCNA in the epithelial of different type of senile cataract and normal lens,and to detect the value of abnormal-differentation and abnormal- proliferation in the formation of cataract.Methods: Anterior capsules for the study were obtained from patients with different types of cataracts during phacoemulsification using continuous curvilinear capsulorhexis,including 36 cortical cataract (55 - 80 years old), 20 nuclear cataract (50 -70 years old), 4 normal lens(35-55 years old). LECs attached to the anterior capsules were analyzed for cellular characteristics by immunohistochemistry. The reactivity to PCNA and to vimentin was measured through Image Pro Plus 5.0 medical color image analysis system. Analyze the data by SPSS11.5,when P<0.01,the differences is significant.Results:1.Vimentin was expressed in cytoplasm;PCNA was expressed in cytoblast.2. Vimentin was expressed in the epithelial of cortical cataract, the IOD/area is 0.1240±0.0448;Vimentin was expressed in the epithelial of nuclear cataract,the IOD/area is 0.0593±0.0151;Vimentin was expressed in the epithelial of normal lens,the IOD/area is 0.0768±0.0351.The expression of vimentin in the epithelial of cortical cataract was significantly higher than in the epithelial of nuclear cataract and normal lens( P<0.01).3. PCNA was expressed in the epithelial of cortical cataract,the IOD/area is 0.0245±0.0089;PCNA was expressed in the epithelial of nuclear cataract,the IOD/area is 0.0627±0.0233;PCNA was expressed in the epithelial of normal lens,the IOD/area is 0.0284±0.0121.The expression of PCNA in the epithelial of nuclear cataract was significantly higher than in the epithelial of cortical cataract and normal lens(P<0.01).Conclusion: The experiment through detected the expression of PCNA and vimentin in the epithelisl cell of cortical cataract,nuclear cataract and normal lens indirectly indicated the proliferation and differentiation.It suggested that cortical cataract and nuclear cataract have different pathogenesises.The nuclear cataract is associated with active proliferation and the cortical cataract is associated with abnormal-differentation.