[关键词]
[摘要]
目的 探讨灯盏花素对糖尿病大鼠心肌缺血再灌注损伤(MIRI)及线粒体自噬途径的影响。方法 采用高糖高脂饮食联合链脲佐菌素制备糖尿病模型,糖尿病模型成功后再制备MIRI模型,具体分组为对照组(不做任何处理)、模型组(糖尿病+MIRI)、假手术组(糖尿病),均ip等体积生理盐水;灯盏花素低、高剂量组(糖尿病+MIRI),分别ip 100、200 mg/kg灯盏花素,每组各10只。连续给药14 d后,全自动血生化仪检测各组大鼠血清总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平变化,ELISA法检测各组大鼠血清中炎性因子白细胞介素-1β(IL-1β)、IL-6、肿瘤坏死因子α(TNF-α)含量,采用超声检测各组大鼠心脏功能变化,HE染色观察各组大鼠心肌组织病理变化,Western blotting检测各组大鼠心肌组织微管相关蛋白轻链3(LC3)、Beclin1、哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸肌醇3-激酶(PI3K)、p-PI3K、蛋白激酶B(Akt)和p-Akt蛋白表达情况。结果 与对照组相比,假手术组、模型组大鼠心肌细胞破碎、坏死,细胞排列不规则,心肌纤维断裂,伴有炎性细胞浸润,大鼠FBG、血清TC、TG、LDL-C水平、心率(HR)、左心室舒张末压(LVEDP),心肌组织LC3-II/LC3-I、Beclin1蛋白表达及血清IL-1β、IL-6、TNF-α水平显著升高(P<0.05),血清HDL-C水平、左心室收缩压(LVSP)、平均动脉压(MAP)和左室射血分数(LVEF)及心肌组织mTOR、p-PI3K/PI3K、p-Akt/Akt蛋白表达显著降低(P<0.05);与模型组相比,灯盏花素低、高剂量组大鼠损伤心肌细胞减少,细胞形态逐渐恢复正常,血清TC、TG、LDL-C水平、HR、LVEDP及心肌组织LC3-II/LC3-I、Beclin1蛋白表达及血清IL-1β、IL-6、TNF-α水平依次降低(P<0.05),血清HDL-C水平、LVSP、MAP、LVEF及心肌组织mTOR、p-PI3K/PI3K、p-Akt/Akt蛋白表达依次升高(P<0.05)。结论 灯盏花素可保护糖尿病MIRI大鼠心肌组织,减轻组织自噬及炎症水平,可能是通过激活线粒体自噬PI3K/Akt/mTOR通路实现的。
[Key word]
[Abstract]
Objective To investigate the effects of breviscapine on myocardial ischemia-reperfusion injury (MIRI) and mitochondrial autophagy pathway in diabetic rats. Methods Diabetes model was established by high sugar and high fat diet combined with streptozotocin. MIRI model was established after the success of diabetes model. The rats were randomly divided into control group (without any treatment), model group (diabetes + MIRI) and sham operation group (diabetes), all of which were intraperitoneally injected with equal volume normal saline; low and high dose breviscapine groups (diabetes + MIRI) were intraperitoneally injected with 100 and 200 mg/kg breviscapine respectively, with 10 rats in each group. After 14 days of continuous administration, the changes of serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were detected by automatic blood biochemical instrument, the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in serum were detected by ELISA, the changes of cardiac function were detected by ultrasound, HE staining was used to observe the myocardial pathological changes, and Western blotting was used to detect the expressions of microtubule-associated protein light chain 3 (LC3), Beclin 1, mammalian target of rapamycin (mTOR), phosphoinositide 3-kinase (PI3K), p-PI3K, protein kinase B (Akt) and p-Akt protein. Results Compared with the control group, the myocardial cells of sham operation group and model group were broken and necrotic, cell arrangement was irregular, myocardial fibers were broken accompanied by inflammatory cell infiltration, FBG, serum TC, TG, LDL-C levels, heart rate (HR), left ventricular end diastolic pressure (LVEDP), LC3-II/LC3-I, Beclin1 protein expression in myocardial tissue, and serum IL-1, IL-6, TNF-α level was significantly increased (P<0.05), serum HDL-C level, left ventricular systolic pressure (LVSP), mean arterial pressure (MAP), left ventricular ejection fraction (LVEF) and mTOR, p-PI3K/PI3K, p-Akt/Akt protein expression in myocardial tissue were significantly decreased (P<0.05). Compared with the model group, the number of injured cardiomyocytes in breviscapine low-dose and high-dose groups decreased, and the cell morphology gradually returned to normal. TC, TG, LDL-C levels in serum, HR, LVEDP, LC3-II/LC3-I, Beclin1 protein expression in myocardial tissue and levels of IL-1β, IL-6, and TNF-α in serum were decreased sequentially (P<0.05), and the level of HDL-C in serum, LVSP, MAP, LVEF, and mTOR, p-PI3K/PI3K, and p-Akt/Akt protein expression in myocardial tissue were increased significantly (P<0.05). Conclusion Breviscapine can protect the myocardial tissue of diabetic rats with MIRI, and reduce the levels of autophagy and inflammation, which may be achieved by activating the mitochondrial autophagy PI3K/Akt/mTOR pathway.
[中图分类号]
R285.5
[基金项目]
河南省科技攻关项目(182102310089)