外源性硫氧还蛋白对高糖、高脂刺激引起的H9c2细胞损伤和凋亡的影响

目的 观察给予外源性硫氧还蛋白（Trx）后对高糖、高脂刺激引起的心肌细胞损伤和凋亡的影响,并分析其可能机制.方法 将处于对数生长期的H9c2心肌细胞随机分为三组：正常对照组（普通DMEM培养基葡萄糖5 mmol/L加入20 mmol/L甘露醇）、高糖高脂组（DMEM高糖25 mmol/L培养基加入高脂600 μmol/L软脂酸）和Trx干预组（在高糖高脂组的培养基中加入3 ＊9滋mol/L Trx）.培养48 h后,分别收集培养基上清与细胞,进行指标检测.结果 与正常对照组比较,高糖高脂组乳酸脱氢酶及caspase-3活性均显著升高（P＜0.01）.给予Trx干预后,与高糖高脂组比较,Trx干预组乳酸脱氢酶及caspase-3活性均显著下降（P＜0.01）.与正常组比较,高糖高脂组Trx的表达量未见明显改变（P＞0.05）,但是Trx活性显著下降（P＜0.01）.结论 高糖、高脂刺激可以引起H9c2心肌细胞损伤和凋亡,其机制与内源性Trx活性的降低有关.外源性补充Trx可明显提高Trx的活性,减轻心肌细胞的损伤和凋亡.

Exogenous thioredoxin reduced cell apoptosis and injury induced by high glucose and high fatty acid in H9c2 cells

Objective To observe the effects of exogenous Trx on the injury and apoptosis in H9c2 cells induced by high glucose and high fatty acid culture, and to investigate its possible mechanisms. Methods The cell culture was randomly divided into 3 groups： Control group （cultured by DMEM with 5 mmol/L glucose and 20 mmol/L mannitol）, High glucose and high fatty acid group （cultured by DMEM with 25 mmol/L glucose and 600 I.Lmol/L palmitate ） and Trx group （cultured by DMEM with 25 mmo]/L glucose, 600 μmol/L palmitate and 3 μmol/L Trx）. H9c2 cells were cultured in different media for 48 hours and then the conditioned media and cells were collected respectively for further assay. Results Compared with control group, high glucose and high fatty acid group showed increased LDH activity and caspase-3 activity （P〈0.01）, while administration of exogenous Trx sigulficant[y reduced both of them compared with high glucose and high fatty acid group （P〈0.01）, compared with control group, Trx activity decreased significantly in high glucose and high fatty acid group （P〈0.01）, however, Trx expression was not changed （P〉0.05）. Conclusion High glucose and high fatty acid culture could invoke injury and apoptosis in H9c2 cells. The underlying mechanism is partly attributed to endogenous Trx activity inhibition but not Trx expression downregulation. Exogenous Trx administration significantly increased Trx activity and thus reduced the myocardial cell injury and apoptosis.