High glucose sensitizes adult cardiomyocytes to ischaemia/reperfusion injury through nitrative thioredoxin inactivation
High glucose sensitizes adult cardiomyocytes to ischaemia/reperfusion injury through nitrative thioredoxin inactivation
复制标题
高葡萄糖通过硝基硫氧还蛋白失活使成年心肌细胞对缺血/再灌注损伤敏感
DOI：
10.1093/cvr/cvp085
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发表时间：
2009-07-15
影响因子：
10.8
通讯作者：
Tao, Ling
中科院分区：
文献类型：
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作者：
Luan, Ronghua;Liu, Shaowei;Tao, Ling
糖尿病患者的缺血性心脏损伤显着增加，但其潜在机制仍不完全清楚。当前的研究试图确定可能导致心肌缺血性损伤的高血糖加剧的新分子机制。成年小鼠心肌细胞在正常葡萄糖（NG，5.5 mM）或高葡萄糖（HG，25 mM）培养基中培养。 NG 或 HG 预培养后 12 小时，心肌细胞在 NG 培养基中进行 3 小时的模拟缺血 (SI)，然后进行 3 小时的再灌注 (R)。 SI/R 之前和之后，确定了以下各项：心肌细胞死亡和凋亡、持续氧化/硝化应激和硫氧还蛋白 (Trx) 活性、表达和硝化。与NG培养的心肌细胞相比，12 h HG培养显着增加了超氧化物和过氧亚硝酸盐的产生，增加了Trx-1硝化，并降低了Trx活性（P < 0.01）。尽管采用相同的 SI/R 程序和条件，但在 HG 中预培养的细胞遭受了更大的损伤，乳酸脱氢酶释放和 caspase-3 激活升高证明了这一点 (P < 0.01)。此外，与NG预培养的心肌细胞相比，SI/R在HG预培养的心肌细胞中诱导更大的超氧化物/过亚硝酸盐过量产生以及更大的Trx-1硝化和失活。最后，在 HG 预培养细胞中补充人 Trx-1、超氧化物清除剂或过氧亚硝酸盐分解催化剂可减少 Trx-1 硝化，保留 Trx-1 活性，并使 SI/R 损伤正常化至 NG 预培养心肌细胞中观察到的水平。高糖通过硝化 Trx-1 失活使心肌细胞对缺血/再灌注损伤敏感。恢复糖尿病心脏中 Trx-1 活性的干预措施可能代表减轻糖尿病患者心脏损伤的新疗法。
Ischaemic cardiac injury is significantly increased in diabetic patients, but its underlying mechanisms remain incompletely understood. The current study attempted to identify new molecular mechanisms potentially contributive to hyperglycaemic-exaggeration of myocardial ischaemic injury.Adult mouse cardiomyocytes were cultured in normal-glucose (NG, 5.5 mM) or high-glucose (HG, 25 mM) medium. Twelve hours after NG or HG pre-culture, cardiomyocytes were subjected to 3 h of simulated ischaemia (SI), followed by 3 h of reperfusion (R) in NG medium. Prior to and after SI/R, the following were determined: cardiomyocyte death and apoptosis, sustained oxidative/nitrative stress and thioredoxin (Trx) activity, expression, and nitration. Compared with NG-cultured cardiomyocytes, 12 h HG culture significantly increased superoxide and peroxynitrite production, increased Trx-1 nitration, and reduced Trx activity (P < 0.01). Despite being subject to identical SI/R procedures and conditions, cells pre-cultured in HG sustained greater injury, evidenced by elevated lactate dehydrogenase release and caspase-3 activation (P < 0.01). Moreover, SI/R induced greater superoxide/peroxynitrite overproduction and greater Trx-1 nitration and inactivation in HG pre-cultured cardiomyocytes than in NG pre-cultured cardiomyocytes. Finally, the supplementation of human Trx-1, superoxide scavenger, or peroxynitrite decomposition catalyst in HG pre-cultured cells reduced Trx-1 nitration, preserved Trx-1 activity, and normalized SI/R injury to levels observed in NG pre-cultured cardiomyocytes.High glucose sensitized cardiomyocytes to ischaemia/reperfusion injury through nitrative Trx-1 inactivation. Interventions restoring Trx-1 activity in the diabetic heart may represent novel therapies attenuating cardiac injury in diabetic patients.