The Influence Of Glucose And Sep15 Gene Knockdown On The Expression Of Pax6 In Human Lens Epithelial Cells

Cataract is a major disease of blindness and visual obstacle.Elucidation of pathogenic mechanism will conduce to the prevention of cataract and even may contribute to its early diagnosis and treatment.The 15-k Da selenoprotein(Sep15,SELENOF)is a thioredoxin-like,endoplasmic reticulum-resident protein.Sep15 gene knockout mice developed a prominent nuclear cataract,but the pathogenic mechanism is not yet clear.The transcription factor(TF)Pax6 is essential for eye development in animals,and normal development of the mammalian eye is dependent on normal expression of Pax6.In this paper,to explore the pathogenic mechanisms of cataract in Sep15 gene knockout mice,effects of glucose and Sep15 gene knockdown on Pax6 gene expression were investigated by si RNA interference,RT-PCR,Western blot techniques in human lens epithelial cell lines(h LECs)SRA01/04.The main results are as follows:(1)The effect of glucose on expression of Pax6 protein showed a stimulation with dependence of concentration and time.The expression of Pax6 protein reached the maximum under the conditions of glucose concentration of 25 m M and treatment time for 24 h,and the osmotic pressure had no effect on the expression of Pax6.Further research shows that glucose promoted the expression of Pax6 in h LECs by activating the phosphorylation signal pathway of AKT and ERK.(2)Sep15 knockdown had no effect on the growth of h LECs,but increased the expression of Pax6 in h LECs.Sep15 regulated the expression of Pax6 in h LECs through phosphorylation of AKT,and increased the expression of PTEN an d Ki67 m RNA and decreased the expression of ?-crystallin and N-Cadherin.The above results suggest that Sep15 regulates the expression of Pax6 gene through the AKT phosphorylation signal pathway.(3)When 25 m M glucose and Sep15 knockdown were respectively treated on h LECs,the expression of Pax6 increased significantly.However when Sep15-gene-knockdown cells exposed to 25 m M glucose,although the cell cycle was not influenced,the expression of Pax6 decreased significantly,meanwhile,the phosphorylation level of AKT and ERK was also decreased.The above results show that glucose and Sep15 may play an important role by regulating Pax6 in proliferation and differentiation of h LEC.