目的：评价还原性谷胱甘肽(GSH)和烟酸联合应用对蛋白质氧化应激、内质网应激(ER)、糖基化和聚合αβ晶状体蛋白的人晶状体上皮(HLE)细胞治疗高葡萄糖水平的影响。

方法：培养HLE细胞并暴露于25 mmol/L葡萄糖中以促进高糖环境。各组细胞用三种不同的剂量组合进行联合治疗：10 μmol/L GSH+2 μmol/L烟酸，30 μmol/L GSH+25 μmol/L烟酸，100 μmol/L GSH+25 μmol/L烟酸。培养72h后，用ELISA法测定蛋白羰基(PCC)和葡萄糖反应蛋白(GRP78)的含量。培养2wk后，对糖基化终末产物(AGEs)进行检测，用Western Blot检测αβ晶状体蛋白的表达。所有数据分析均采用SPSS 18.0统计软件包。

结果：与对照组相比，联合治疗组的PCC和GRP78水平没有显著降低(P>0.05)。相反，与对照组相比，GSH和烟酸联合治疗组的AGEs水平明显下降(P<0.05)。此外，高剂量葡萄糖给药后αβ晶状体蛋白表达增加，但GSH联合治疗组与GSH和烟酸联合治疗组αβ晶状体蛋白表达都有所降低。

结论：结果表明，GSH和烟酸联合应用可抑制高血糖人HLE细胞蛋白质的聚合，防止糖基化，并且通过AGEs途径在预防糖尿病性白内障中发挥积极作用。

METHODS:HLE cells were cultured and exposed to 25 mmol/L glucose to promote high glucose conditions. Groups of cells were co-treated with three different combinations of dosages: 10 μmol/L GSH+2 μmol/L niacin, 30 μmol/L GSH+25 μmol/L niacin, and 100 μmol/L GSH+25 μmol/L niacin. After 72h incubation, protein carbonyl content(PCC)and glucose reactive protein(GRP78)content were assessed using ELISA examinations. After two-week incubation, advanced glycation end products(AGEs)were also assessed and the expression of αβ crystalline was measured using Western Blot examination. The SPSS 18.0 statistical package was used for all data analyses.

RESULTS:PCC and GRP78 levels in the co-treated groups were not significantly reduced compared to control(P>0.05). In contrast, there was a significant decrease of the AGEs levels in all groups co-treated with GSH and niacin when compared with the control group(P<0.05). In addition, the αβ crystalline expression increased after high dose glucose administration, but decreased in all groups co-treated with GSH and combinations of GSH and niacin.

CONCLUSION:The results suggest that combinations of GSH and niacin inhibit the aggregation of proteins and prevent glycation in hyperglycemic human lens epithelial cells. This study shows that this combination may play an active role in preventing diabetic cataract mainly from the AGEs pathway.