Objective: To observe the effect of electroacupuncture (EA) on expression of interleukin (IL) -23/IL-17 axis and Toll-like receptor 4 (TLR4) in the infarcted tissue in rats with myocardial infarction (MI), and to explore the mechanism of EA on alleviating MI injury.
Methods: Forty male SD rats were randomly divided into a sham-operation group, a sham-operation plus EA group, a model group and an EA group, 10 rats in each group. The MI models were established by ligation of left anterior descending coronary artery in the model group and EA group, while only threading was performed in the sham-operation group and sham-operation plus EA group. The rats in the sham-operation plus EA group and EA group were treated with EA at "Neiguan" (PC 6), disperse-dense wave, 2 Hz/100 Hz, 2 mA, once a day, 20 min each time, for 3 days. After the intervention, the ejection fraction (EF) was measured by echocardiography to evaluate the cardiac function; the infarct area was measured by TTC staining; the HE staining was used to observe the morphological changes of myocardial tissue; the levels of IL-23 and IL-17 in infarcted tissue were detected by ELISA; the protein expression of TLR4 in infarcted tissue was detected by Western blot.
Results: Compared with the sham-operation group, the EF was decreased (P<0.01), the infarct area was increased (P<0.01), the myocardial fiber injury was obvious, accompanied by inflammatory cell infiltration, and the contents of IL-23, IL-17 and the expression of TLR4 in infarcted tissue were increased in the model group (P<0.01). Compared with the model group, the EF was increased (P<0.05), the infarct area was reduced (P<0.05), the myocardial fiber injury was significantly improved, the inflammatory cell infiltration was reduced, and the contents of IL-23, IL-17 and TLR4 expression in infarcted tissue were decreased in the EA group (P<0.05).
Conclusion: EA may alleviate the excessive inflammatory response after MI by inhibiting the expression of IL-23/IL-17 axis in MI rats, and TLR4 may be involved during the process.
目的：观察电针对心肌梗死（MI）大鼠梗死组织中白细胞介素（IL）-23/IL-17轴和Toll样受体4（TLR4）表达的影响，探讨电针减轻MI损伤的机制。方法：将40只雄性SD大鼠随机分为假手术组、假手术电针组、模型组和电针组，每组10只。模型组和电针组均采用冠状动脉左前降支（LAD）结扎法制备MI模型，假手术组和假手术电针组仅穿线不结扎。假手术电针组和电针组在“内关”穴进行电针（疏密波，2 Hz/100 Hz，2 mA）干预，每天1次，每次20 min，干预3 d。干预结束后，采用超声心动图检测大鼠心脏射血分数（EF）评价心功能；TTC染色法测定大鼠心肌梗死面积；HE染色法观察大鼠心肌组织形态学变化；ELISA法检测大鼠心肌梗死组织IL-23、IL-17含量；Western blot法检测大鼠心肌梗死组织TLR4的蛋白表达。结果：与假手术组比较，模型组大鼠EF降低、心肌梗死面积增大（P<0.01），心肌纤维损伤明显、并伴有炎性细胞浸润，心肌梗死组织IL-23、IL-17含量及TLR4蛋白表达升高（P<0.01）；与模型组比较，电针组大鼠EF升高、心肌梗死面积缩小（P<0.05），心肌纤维损伤情况明显改善、炎性细胞浸润减少，心肌梗死组织IL-23、IL-17含量及TLR4蛋白表达降低（P<0.05）。结论：电针可能通过抑制IL-23/IL-17轴的表达来缓解心肌梗死后的过度炎性反应，TLR4可能参与其中。.
Keywords: IL-23/IL-17 axis; Toll-like receptor 4; electroacupuncture; myocardial infarction.