CAJ | 학술논문

目的:本研究旨在阐明硫氧还蛋白(Trx)心肌保护作用的机制.方法:采用成年雄性小鼠心肌30 min缺血/3 h再灌注模型,再灌注前10 min随机给予磷酸缓冲液(PBS,对照)或重组人Trx (hTrx,2 mg/kg) 腹腔注射.在再灌注终末,摘取实验动物的心脏,分别检测心肌细胞凋亡和心肌组织中硝基酪氨酸的含量.结果:再灌注前给予Trx可以显著减少缺血/再灌注导致的心肌细胞凋亡(P＜0.01);与对照组相比,Trx组心肌组织中硝基酪氨酸的含量显著减少 (4.8±0.53 比 9.5±0.86 pmol/mg蛋白质,P＜0.01), 提示Trx可能通过阻断蛋白硝基化和随后的细胞凋亡而发挥心脏保护作用.为了寻找Trx可以阻断蛋白硝基化的直接证据,在培养的成年心肌细胞给予SIN-1 (过氧亚硝酸阴离子供体) 50 μmol处理、或SIN-1 和hTrx(500 nmol)共同处理后,观察Trx 在过氧亚硝酸阴离子诱导的细胞凋亡中的作用.结果表明SIN-1 处理导致心肌细胞凋亡显著增加 (P＜0.01),Trx可以显著减少SIN-1导致的心肌细胞凋亡(P＜0.01) .结论:硫氧还蛋白,一种新的抗凋亡和心肌保护分子,通过阻断过氧亚硝酸阴离子导致的蛋白硝基化和随后的细胞凋亡而发挥心脏保护作用.
목적:본연구지재천명류양환단백(Trx)심기보호작용적궤제.방법:채용성년웅성소서심기30 min결혈/3 h재관주모형,재관주전10 min수궤급여린산완충액(PBS,대조)혹중조인Trx (hTrx,2 mg/kg) 복강주사.재재관주종말,적취실험동물적심장,분별검측심기세포조망화심기조직중초기락안산적함량.결과:재관주전급여Trx가이현저감소결혈/재관주도치적심기세포조망(P＜0.01);여대조조상비,Trx조심기조직중초기락안산적함량현저감소 (4.8±0.53 비 9.5±0.86 pmol/mg단백질,P＜0.01), 제시Trx가능통과조단단백초기화화수후적세포조망이발휘심장보호작용.위료심조Trx가이조단단백초기화적직접증거,재배양적성년심기세포급여SIN-1 (과양아초산음리자공체) 50 μmol처리、혹SIN-1 화hTrx(500 nmol)공동처리후,관찰Trx 재과양아초산음리자유도적세포조망중적작용.결과표명SIN-1 처리도치심기세포조망현저증가 (P＜0.01),Trx가이현저감소SIN-1도치적심기세포조망(P＜0.01) .결론:류양환단백,일충신적항조망화심기보호분자,통과조단과양아초산음리자도치적단백초기화화수후적세포조망이발휘심장보호작용.
To determine the mechanism responsible for thioredoxin(Trx )cardioprotective effect. Method: Adult male mice were subjected to 30 min of myocardial ischemia (MI) followed by 3 h reperfusion(R). Mice were randomized to receive vehicle (PBS)or human Trx(hTrx,2 mg/kg, ip.) 10 min before R. At the end of the reperfusion period, the animal heart was quickly excised, and the ischemic/reperfused cardiac tissue was isolated. The levels of myocardial apoptosis and nitrotyrosine were determined 3 h after R. Results: Treatment with hTrx before R decreased significantly post-ischemic myocardial apoptosis (p ＜0.01). Moreover, the level of cardiomyocyte protein nitration represented by nitrotyrosine reduced markedly in animals treated with Trx (4.8±0.53 vs. 9.5±0.86 pmol/mg protein, p ＜0.01), which suggests that Trx may exert its cardioprotective effect by blocking protein nitration and subsequent apoptosis. To further demonstrate a causative-link between the anti-nitrative and cardioprotective effect of Trx, peroxynitrite was added in cultured adult cardiomyocytes and the effect of Trx on peroxynitrite-induced apoptosis were determined. Incubation of cardiomyocytes with SIN-1 (50 μmol, a peroxynitrite donor) for 3 h caused significant cardiomyocyte apoptosis (P＜0.01). Treatment with Trx decreased markedly apoptosis induced by SIN-1 (P＜0.01). Conclusion: It is demonstrated that Trx is a novel anti-apoptotic and cardioprotective molecule that exerts its cardioprotective effects by blocking peroxynitrite-induced protein nitration and subsequent apoptosis.