硝化应激在高糖致心肌细胞损伤记忆效应中的作用

Role of nitrification stress in memory effect of myocardial cell injury induced by high glucose

目的观察体外高糖因素对心肌细胞的损伤是否存在"代谢记忆"效应,并探讨硝化应激在此效应中的作用。方法将培养的心肌细胞分为四组:正常糖组(NG,5.5mmol/L D-葡萄糖×8d)、高糖组(HG,25mmol/L D-葡萄糖×8d)、记忆组(M,25mmol/L D-葡萄糖×4d+5.5mmol/LD-葡萄糖×4d)和记忆+氨基胍组(MA,25mmol/L D-葡萄糖×4d+5.5mmol/L D-葡萄糖×4d+0.5mmol/L氨基胍)。MTT法检测细胞存活率,流式细胞术检测细胞凋亡,Western blot检测诱生型一氧化氮合酶(iNOS)表达并进行半定量分析,ELISA法检测3-硝基酪氨酸(3-NT)含量。结果与NG组相比,HG组和M组细胞存活率下降(P<0.05),凋亡率上升(P<0.05),iNOS表达和3-NT含量增多(P<0.05)。与M组相比,MA组细胞存活率上升(P<0.05),凋亡率下降(P<0.05),iNOS表达和3-NT含量减少(P<0.05)。结论高糖致心肌细胞损伤存在"代谢记忆"效应,且硝化应激可能参与了此效应。

Objective To investigate the ＂metabolic memory＂ of high glucose on myocardial cell injury and the role of nitrification stress in the effect. Methods The cultured myocardial cells were divided into four groups of NG（treated with D-glucose 5.5 mmol/L for 8 d）,HG（treated with D-glucose 25 mmol/L for 8 d）,M（treated with D-glucose 25 mmol/L for 4 d and 5.5 mmol/L for 4 d）, MA（treated with D-glucose 25 mmol/L for 4 d and 5.5 mmol/L for 4 d plus aminoguanidine 0.5 mmol/L）.The cell viability was measured by MTT and apoptosis was detected by flow cytometry. Inducible nitric oxide synthase（iNOS） expression was analyzed by Western blot and 3-nitrotyrosine（3-NT） content was measured by ELISA. Results Compared with group NG,the cell viability was decreased,but the apoptosis rate,iNOS expression and 3-NT content were increased in groups of M and HG（P0.05）.Compared with group M,the cell viability was increased,but the apoptosis rate,iNOS expression and 3-NT content were decreased in group MA（P0.05）. Conclusion ＂Metabolic memory＂ effect exists in high glucose-induced myocardial injury,in which nitrification stress may be involved.