Liu Qiong-Qiong, Zhang Hong-Ru, Gu Yi-Huang
School of Acupuncture and Tuina & Health Preservation and Rehabilitation, Nanjing University of Chinese Medicine, Nanjing 210023, China.
Dan'an College, Nanjing University of Chinese Medicine, Nanjing 210023.
Zhen Ci Yan Jiu. 2024;49(9):902-908. doi: 10.13702/j.1000-0607.20230141.
To observe the effect of electroacupuncture(EA) on adenosine 5'-monophosphate-activated protein kinase (AMPK)/Kruppel-like factor 2 (KLF2) signaling pathway in ischemic myocardial tissues of rats, so as to explore the underlying mechanism of EA in attenuating myocardial ischemia-reperfusion injury (MIRI) through mediating angiogenesis.
Male SD rats were randomly divided into sham operation group, model group and EA group, with 10 rats in each group. The MIRI model was established by ligation of the anterior descending branch of the left coronary artery. Twenty-four hours after modeling, the rats in the EA group were given EA (2 Hz/100 Hz, 2 mA) at "Neiguan" (PC6) for 20 min each time, once a day for 5 consecutive days. Echocardiography was used to detect cardiac ejection fraction (EF) to evaluate cardiac function. HE staining was used to observe the morphological changes in rat myocardial tissue. Immunohistochemistry was used to detect the density of neovascularization in rat ischemic myocardium. Western blot and ELISA were used to detect the phosphorylated(p)-AMPK, AMPK, KLF2, vascular endothelial growth factor (VEGF) protein expression levels, and VEGF receptor 2 (VEGFR2) content in rat ischemic myocardial tissue, respectively.
After modeling, compared with the sham operation group, rats in the model group had decreased EF(<0.01), significant myocardial fiber damage with inflammatory cell infiltration, increased neovascular density (<0.05), increased p-AMPK, AMPK, VEGF protein expression levels and VEGFR2 content in myocardial ischemic tissues(<0.05, <0.01), and decreased protein expression level of KLF2 (<0.05). After EA intervention, compared with the model group, rats in the EA group had elevated EF(<0.01), significantly reduced myocardial fiber damage, reduced inflammatory cell infiltration, increased neovascular density(<0.01), and elevated p-AMPK, AMPK, KLF2, and VEGF protein expression levels and VEGFR2 content in the myocardial ischemic tissue (<0.01).
EA may promote angiogenesis, attenuate myocardial injury, and achieve cardioprotective effects in MIRI rats by regulating the expression of AMPK/KLF2 signaling pathway in myocardial tissues.
观察电针（EA）对大鼠缺血心肌组织中5'-单磷酸腺苷激活蛋白激酶（AMPK）/ Kruppel样因子2（KLF2）信号通路的影响，以探讨EA通过介导血管生成减轻心肌缺血再灌注损伤（MIRI）的潜在机制。
将雄性SD大鼠随机分为假手术组、模型组和EA组，每组10只。通过结扎左冠状动脉前降支建立MIRI模型。造模后24小时，对EA组大鼠在“内关”（PC6）穴给予EA（2 Hz/100 Hz，2 mA），每次20分钟，每天1次，连续5天。采用超声心动图检测心脏射血分数（EF）以评估心功能。采用苏木精-伊红（HE）染色观察大鼠心肌组织形态学变化。采用免疫组织化学检测大鼠缺血心肌组织新生血管密度。分别采用蛋白质免疫印迹法（Western blot）和酶联免疫吸附测定法（ELISA）检测大鼠缺血心肌组织中磷酸化（p）-AMPK、AMPK、KLF2、血管内皮生长因子（VEGF）蛋白表达水平及VEGF受体2（VEGFR2）含量。
造模后，与假手术组比较，模型组大鼠EF降低（<0.01），心肌纤维损伤明显，有炎性细胞浸润，新生血管密度增加（<0.05），心肌缺血组织中p-AMPK、AMPK、VEGF蛋白表达水平及VEGFR2含量升高（<0.05，<0.01），KLF2蛋白表达水平降低（<0.05）。EA干预后，与模型组比较，EA组大鼠EF升高（<0.01），心肌纤维损伤明显减轻，炎性细胞浸润减少，新生血管密度增加（<0.01），心肌缺血组织中p-AMPK、AMPK、KLF2及VEGF蛋白表达水平和VEGFR2含量升高（<0.01）。
EA可能通过调节心肌组织中AMPK/KLF2信号通路的表达促进血管生成，减轻心肌损伤，对MIRI大鼠发挥心脏保护作用。
