miR-21靶向调控配体蛋白1在心肌梗死大鼠心肌纤维化中的作用机制

Effect of microRNA-21 targeted ligand protein 1 on myocardial fibrosis in rats with acute myocardial infarction

目的探讨miR-21靶向调控配体蛋白1(Jagged-1)在心肌梗死大鼠心肌纤维化的作用。方法将大鼠随机分成4组,每组15只:假手术组、模型组、阴性对照组和实验组。假手术组、模型组大鼠心脏冠状动脉注射磷酸盐缓冲液(phosphate buffer solution,PBS),阴性对照组和实验组大鼠分别心脏冠状动脉注射rAAV9-miR-21-inhibitors-NC病毒载体和rAAV9-miR-21-inhibitors病毒载体。采用结扎左前降支冠状动脉的方法来构建心肌梗死大鼠模型。氯化三苯基四氮唑(triphenyl tetrazolium chloride,TTC)染色检测各组大鼠心肌梗死比例,免疫组化法检测心肌组织测Ⅰ、Ⅲ型胶原蛋白表达,Western blot检测各组大鼠心肌组织中α-平滑肌肌动蛋白(α-SMA)、跨膜融合蛋白1(Notch1)和配体蛋白1(Jagged-1)蛋白的表达。结果假手术组、模型组、阴性对照组、实验组的心肌梗死比例分别为0,(57.48±6.58)%,(56.88±7.08)%和(21.06±3.33)%;Ⅰ型胶原蛋白的表达分别为1.01±0.05,4.75±0.32,4.55±0.52和1.89±0.08;Ⅲ型胶原蛋白的表达分别为0.99±0.08,7.82±0.18,7.85±0.14和2.15±0.26;α-SMA的相对表达量分别为1.00±0.04,5.78±0.22,5.75±0.25和2.56±0.38;Notch1的相对表达量分别为0.98±0.07,4.22±0.35,4.15±0.41和2.07±0.33;Jagged-1的相对表达量分别为1.01±0.06,4.38±0.25,4.33±0.31和1.78±0.17。模型组与假手术组比较,实验组与模型组比较,差异均有统计学意义(均P<0.05)。结论 miR-21可靶向调控Jagged-1的表达,抑制心肌梗死大鼠的心肌纤维化。

Objective To investigate the role of miR-21 in target regulating ligand protein 1(Jagged-1) in myocardial fibrosis(MF) in rats with acute myocardial infarction(AMI).Methods Rats were randomly divided into 4 groups, 15 in each group: sham-operation group, model group, the negative control group and experimental group. The rats in the sham operation group and the model group were injected with phosphate buffer solution(PBS) in the coronary heart, and the rats in the negative control group and the experimental group were injected with rAAV9-miR-21-inhibitors-NC virus vector and rAAV9-miR-21-inhibitors viral vector. The rat model of myocardial infarction was constructed by ligating the left anterior descending coronary artery. Triphenyl tetrazolium chloride(TTC) staining was used to detect the proportion of myocardial infarction in each group. Immunohistochemical method was used to detect myocardial tissue to detect the expression of type Ⅰ and type III collagen. Western blot was used to detect the expression of α-smooth muscle actin(α-SMA),Notch homolog 1(Notch1) and ligand protein 1(Jagged-1) proteins. Results The proportions of myocardial infarction in the sham operation group, model group, negative control group and experimental group were 0,(57. 48 ± 6. 58) %,(56. 88 ± 7. 08) %,and(21. 06 ± 3. 33) %;the relative expression of type Ⅰ collagen were 1. 01 ± 0. 05,4. 75 ± 0. 32,4. 55 ± 0. 52,and 1. 89 ± 0. 08;the relative expressions of type Ⅲ collagen were 0. 99 ± 0. 08,7. 82 ± 0. 18,and 7. 85 ± 0. 14 and 2. 15 ± 0. 26;the relative expression levels of α-SMA were 1. 00 ± 0. 04,5. 78 ± 0. 22,5. 75 ± 0. 25, and 2. 56 ± 0. 38;the relative expression levels of Notch1 were 0. 98 ± 0. 07,4. 22 ± 0. 35,4. 15 ± 0. 41,and 2. 07 ± 0. 33;the relative expressions of Jagged-1 were 1. 01 ± 0. 06,4. 38 ± 0. 25,4. 33 ± 0. 31 and 1. 78 ± 0. 17. There were significant differences of the factors between model group and the sham operation group or experimental group and model group(all P < 0. 05). Conclusions miR-21 can regulate Jagged-1 and inhibit MF in AMI rats.