Effect Of Sep15 Gene Silencing On Expression Of Crystallins In Human Lens Epithelial Cells

Cataract is the leading cause of worldwide blindness disease, and it seriously affects the quality of human life. So, the research on the pathogenesis and prevention of cataract has an important scientific significance.Normal differentiation of lens epithelial cells is the foundation to ensure the normal development and function of lens. Once the cells differentiation process was distrubed, it would lead to the lens lesions and induce cataract formation. Previous study showed that Sep15 knockout lead to the mice cataract formation, but the mechanism remains unclear. In present study, ?-Crystallin in human lens epithelial(hLE) cells SRA01/04 was selected as the research object, because it is a biomarker of lens epithelial cell differentiation; the effects of endoplasmic reticulum(ER) stress induced by tunicamycin(Tm) or/and Sep15 gene silencing on ?-Crystallin expression in hLE cells were studied using the methods of MTT, real- time quantitative PCR, Western blotting and so on. The main results are as follows:(1) The inhibition role of Tm with different concentrations on the cells viability was in a dose-dependent manner. When the cells were treated with Tm of 5.0 ?g/mL, the expression of GRP78 protein was significantly up-regulated, showing that ER stress occurred; meanwhile the expression of ?-Crystallin was greatly inhibited.(2) Low concentration of basic fibroblast growth factor(bFGF) could promote the cell proliferation, while the high concentration of bFGF could induce cell death in hLE cells. When bFGF with the concentration of 40 ng/mL treated the cells, the expressions of ?-,?-Crystallin protein were up-regulated, thereinto ?-Crystallin was more significant, suggesting that bFGF of 40 ng/mL could promote differentiation of hLE cells. While the cells were treated with Tm and bFGF together, the expression of ?-Crystallin was significantly inhibited due to ER stress induced by Tm, when compared to the group of bFGF.(3) Sep15 gene silencing did not obviously affect GRP78 protein expression, but aggravated the inhibition of expression of ?-Crystallin caused by Tm inducing ER stress. Our results showed that Sep15 played a protective role on the differentiation of hLE cells by regulating ?-Crystallin expression, however, its protective mechanism is not by inhibiting ER stress inducd by Tm in hLE cells.