Expression Of Neovascular Associated Factors PEDF And αB-crystallin In Human Lens Epithelial Cells

Objective To investigate the expression of pigment epithelium-derived factor(PEDF)and αB-crystallin in human lens epithelial cells(LEC)and explore their relationships with diabetic retinopathy(DR).To provide a theoretical basis for the mechanism of iris neovascularization after cataract surgery in diabetic patients.Methods Lens anterior capsules were collected from patients with age-related cataract in surgeries.Depending on the history of diabetes,patients were divided into two groups: non-diabetes mellitus(NDM)group and diabetes mellitus(DM)group.The DM group was subdivided into no diabetic retinopathy(NDR)group,non-proliferative diabetic retinopathy(NPDR)group and proliferative diabetic retinopathy(PDR)group through fundus examination.LEC is a monolayer of epithelial cells adhering to lens anterior capsules.In this study,the distribution and expression of PEDF and αB-crystallin protein in LEC were detected by immunofluorescence and western blot assay.Results(1)In each lens anterior capsule sample,the central region LEC is mostly a regular single layer of cubic epithelium and attached to the inner surface of the anterior lens capsule.PEDF and αB-crystallin were both present in LEC under lens anterior capsules.PEDF is mainly distributed in the cytoplasm,whereas αB-crystallin was located in both cytoplasm and nucleus.(2)With the appearance and aggravation of DR,the expression of PEDF protein in LEC increased gradually.The expression of PEDF protein of PDR group was significantly higher than the other three groups(P<0.001).(1)In the equal amount of protein in each sample tissue,the expression level of PEDF protein showed significant difference between groups(P<0.01).(2)With the appearance and progression of DR,the expression level of PEDF protein in LEC(relative to internal reference)was 0.31±0.24(NDM group),0.27±0.23(NDR group),0.81±0.46(NPDR group)and 2.19±0.39(PDR group)respectively,showed a significant upward trend(P<0.05).(3)The expression of αB-crystallin in LEC also increased with the appearance of DR(P<0.01).(1)In the equal amount of protein in each sample tissue,the expression level of αB-crystallin showed significant inter-group differences(P<0.05).(2)With the appearance and progression of DR,the expression level of αB-crystallin in LEC(relative to internal reference)was 2.17±0.97(NDM group),2.60±1.12(NDR group),3.50± 1.43(NPDR group)and 4.59 ± 1.19(PDR group)respectively,showed a significant upward trend(P<0.05).Conclusion The expression of PEDF and αB-crystallin protein is present in human LEC.PEDF is mainly distributed in cytoplasm,while αB-crystallin can be expressed in both cytoplasm and nucleus.The expression of PEDF and αB-crystallin protein in LEC were both positively correlated with the progression of DR,suggesting that human lens may participate in the regulation of neovascularization through the expression of neovascular associated factors and the formation of iris neovascularization after cataract surgery in diabetic patients may be related to this regulation.