维生素E对不同糖浓度培养LO2细胞铁代谢相关蛋白表达的影响

Effects of vitamin E on iron metabolism-related proteins of LO2 cells induced by different concentrations of glucose

目的探讨维生素E对不同浓度葡萄糖培养下LO2肝细胞株铁调节蛋白1(IRP1)、转铁蛋白受体1(TfR1)、转铁蛋白受体2(TfR2)、铁调素(hepcidin)表达的影响。方法 LO2细胞培养基分为5.5,15,25 mmol/L三种葡萄糖浓度。分别在这三种葡萄糖浓度培养中,再分别加入0,0.1,1 mg/L和10 mg/L维生素E。其中0 mg/L维生素E剂量组作为相同葡萄糖浓度组中的对照组。各组培养时间均为24 h。用荧光染色法检测各组细胞活性氧(ROS)水平,用蛋白免疫印迹法检测IRP1、TfR1、TfR2、hepcidin的表达量。结果①相同葡萄糖浓度组与0 mg/L维生素E对照组相比,5.5 mmol/L组添加各剂量维生素E后细胞ROS水平、IRP1、TfR1和TfR2表达没有显著差异(P>0.05);15 mmol/L组和25 mmol/L组中1 mg/L和10 mg/L维生素E组分别与其对照组相比,细胞ROS水平、IRP1、TfR1和TfR2表达分别下降(P<0.01);15 mmol/L和25 mmol/L组中0.1 mg/L维生素E组与相应对照组相比细胞ROS水平、IRP1、TfR1和TfR2表达没有显著差异(P>0.05)。②相同剂量维生素E组内:LO2细胞ROS水平、IRP1、TfR1、TfR2表达量分别随葡萄糖浓度的升高而逐渐升高(P<0.01)。③在各葡萄糖浓度组内,各剂量维生素E组间细胞的hepcidin表达没有显著性差异(P>0.05)。在各剂量维生素E组中,15 mmol/L和25mmol/L葡萄糖组与相应5.5 mmol/L葡萄糖组相比,hepcidin表达显著升高(P<0.01),而15 mmol/L和25 mmol/L组间hep-cidin表达没有显著差异(P>0.05)。结论维生素E能够降低高糖培养下细胞活性氧的含量,缓解IRP1、TfR1、TfR2蛋白表达增加的幅度。hepcidin表达变化并没有受维生素E的影响,提示hepcidin在高糖环境下的表达增加可能不是或不仅仅是受过量ROS的影响。

Objective To investigate the effects of vitamin E on iron metabolism-related proteins of LO2 cells induced by different concentrations of glucose.Methods A total of 12 groups of LO2 cells were treated with four concentrations of vitamin E（0,0.1,1,10 mg/L） in the medium containing three concentrations of glucose（5.5,15,25 mmol/L glucose） for 24 h,respectively.The 0 mg/L vitamin E groups were taken as the control groups respectively in the three concentrations of glucose.The production of reactive oxygen species（ROS） was detected by reactive oxygen species assay.The expression of iron regulatory protein 1（IRP1）,transferrin receptor 1（TfR1）,transferrin receptor 2（TfR2）,hepcidin were detected by Western blot respectively.Results ①Compared with the 0 mg/L vitamin E control groups,the expression of ROS,IRP1,TfR1,TfR2 showed no significant difference in 5.5 mmol/L glucose groups.Compared with 0 mg/L vitamin E controls,the expression of ROS,IRP1,TfR1 and TfR2 were decreased after treated with 1 mg/L and 10 mg/L vitamin E in 15 mmol/L and 25 mmol/L glucose groups（P〈0.01）,but no significant difference after treated with 0.1 mg/L vitamin E（P〉0.05）.②In groups of the same concentration of vitamin E,the expression of ROS,IRP1,TfR1,TfR2 increased gradually with the rising glucose concentration（P〈0.01）.③After giving the same concentration of glucose,there was no significant difference in the expression of hepcidin among different concentrations of vitamin E groups（P〉0.05）.After giving the same concentration of vitamin E,the expression of hepcidin in 15 mmol/L and 25 mmol/L glucose groups were significantly higher than in 5.5 mmol/L group（P〈0.001）.However,there was no significant change in the expression of hepcidin between 15 mmol/L and 25 mmol/L groups after treated with different concentrations of vitamin E（P〉0.05）.Conclusion Vitamin E can reduce the formation of ROS and partially ease the upregulation of IRP1,TfR1,TfR2 in LO2 cells cultured with high glucose.The expression of hepcidin is not affected by vitamin E,suggesting that the increased expression of hepcidin may not or not only be induced by excessive ROS in high glucose environment.