SUMO Expression and Regulation in Oxidative Stress in Cultured Human Lens Epithelial Cells / 中国医科大学学报

ABSTRACT

Objective To observe the expression of small ubiquitin?related modifiers(SUMO)protein in normal cultured human lens epithelial cells(SRA01/04)and discuss regulation effects of SUMO protein on oxidative stress induced by high glucose. Methods The expression and local?ization of SUMO 1,2/3,4 was detected in normal cultured SRA01/04 cells through immunocytochemistry. The mRNA expression levels of SUMO 1?4 were examined by RT?PCR after the SRA01/04 cells treated with high glucose media at different concentrations and time points. Samples were grouped by medium concentrations(glucoses 5.5 mmol/L,12.5 mmol/L,25 mmol/L,50 mmol/L respectively for 24 h)and by treatment time(0 h, 6 h,12 h and 24 h respectively). After highly efficient transfection of GFP?SUMO2 into SRA01/04 cells,the survival and apoptotic rates of transfect?ed and un?transfected cells treated with high glucose was detected by CCK8 method and AV/PI double staining flow cytometry. Results The immu?nocytochemistry results showed that SUMO1,2/3,4 proteins were mainly located in the nucleus of SRA01/04 cells and part of SUMO2/3 was in the cytoplasm. RT?PCR results showed that compared with the low?glucose group,the mRNA expression of SUMO1?4 was increased along the increas?ing glucose concentration in the high?glucose group(P<0.05). Compared with 0 h,the mRNA expression of SUMO1?4 was enhanced at 6 h,12 h and 24 h(P<0.05)in the high?glucose group treated at 50 mmol/L concentration. Compared with the un?transfected cells,the survival rate was in?creased and the apoptotic rate was decreased in GFP?SUMO2 transfected cells in oxidative stress induced by high glucose(P<0.05). Conclusion SUMO protein was positively expressed in SRA01/04 cells and the expression of SUMO mRNA was affected by oxidative stress induced by high glu?cose.