急性心肌梗死后大鼠炎症细胞因子表达和心室重塑的关系

Relationship of gene expression of inflammatory cytokines with cardiac remodeling in rats after acute myocardial infarction

目的:探讨急性心肌梗死(AMI)后大鼠心脏炎症细胞因子TNF-α,IL-1β,IL-6和IL-10基因表达和心室重塑的关系。方法:大鼠分2组,①假手术组(Sham),不结扎左冠状动脉前降支(LAD);②心肌梗死组(MI):结扎LAD。动物笼养4周,作超声心动图检查心脏结构和功能;然后处死大鼠,取出心脏,沿乳头肌等分为二,一半用RT-PCR法测定心脏细胞因子mRNA表达,另一半用Westernblot测定细胞因子蛋白生成量。结果:超声心动图显示,同Sham组相比,MI组LVEDd显著增加、FS和EF明显降低(P均<0.01)。Sham组上述细胞因子均无明显表达,MI组TNF-α,IL-1β,IL-6和IL-10mRNA表达和蛋白产生均显著高于Sham组(P<0.01)。直线相关分析显示,致炎症细胞因子蛋白表达同LVEDd呈正相关,而抗炎症细胞因子蛋白表达同LVEDd呈负相关。结论:AMI后大鼠心脏内致炎症细胞因子和炎症保护因子IL10都升高,炎症细胞因子参与了AMI后的心室重塑。

Objective: To investigate the association of gene expression of inflammatory cytokines, including TNF-α, IL-1β, IL-6 and IL-10, with cardiac remodeling in rats after acute myocardial infarction (AMI).Methods: The rats were divided into two groups: ①Sham group (Sham), the left anterior descending coronary arteries (LADs) of rats were not ligated; ②AMI group (MI): the LADs were ligated. All animals were caged to fed 4 weeks. At the fourth week, the echocardiography was carried out to measure left ventricular end-diastolic diameter (LVEDd), ejection fraction (EF), and LV fractional shortening (FS). Thereafter, the rats were killed, hearts harvested and cut to two equal parts: one was used to determine mRNA expression of cardiac cytokines by RT-PCR, another used to measure protein production of cytokines by western blot.Results: The echocardiography showed that, compared with Sham group, the LVEDd significantly increased, EF and FS markedly decreased in MI group (P<0.05, respectively).All[HJ1.4mm] of inflammatory cytokines mentioned above showed no expression in Sham group. In the MI group, both mRNA expression and protein production of these cytokines markedly increased (P<0.01, respectively). There existed a positive correlation between protein production of pro-inflammatory cytokines and LVEDd, and a negative correlation between protein production of anti-inflammatory cytokine and LVEDd.Conclusion: Both pro-inflammatory and anti-inflammatory cytokines significantly increased in rats after AMI, the inflammatory cytokines were involved in ventricular remodeling of AMI-rats.