miR-429对低氧诱导的缺血性脑卒中的血管生成作用机制研究

The mechanism of miR-429 on angiogenesis of ischemic stroke induced by hypoxia

目的探讨mi R-429对低氧诱导的缺血性脑卒中的血管生成作用机制研究。方法线栓法建立永久性局灶脑缺血大鼠模型,随机分为4组进行不同处理:(1)antagomi R-Ctr组:常氧预处理并注射antagomi R-Ctr;(2)antagomi R-429组:常氧预处理并注射antagomi R-429;(3)Co Cl2+antagomi R-Ctr组:Co Cl2预处理并注射antagomi R-Ctr;(4)Co Cl2+antagomi R-429组:Co Cl2预处理并注射antagomi R-429。Co Cl2溶液和antagomi R-Ctr/429的剂量分别是30mg·kg-1和12mg·kg-1。通过实时荧光定量核酸扩增检测系统(QPCR)和蛋白印迹试验(Western blot)检测各组HIF-1α、VEGF和mi R-429的表达,通过异硫氢酸荧光素葡聚糖(FITC-Dextran)和氯化三苯基四氮唑(TTC)染色分别检测微血管密度和梗死体积。结果在脑缺血后第7d和21d,Co Cl2预处理和antagomi R-429能诱导大鼠低氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)的表达,降低mi R-429的表达,并促进血管生成和缩小梗死体积;脑缺血后第7d,Co Cl2+antagomi R-429组较其余3组HIF-1α和VEGF的表达最高,mi R-429的表达最低,微血管密度最大且梗死体积最小,且在脑缺血后第21d,此趋势更明显。结论 Antagomi R-429促进低氧诱导的脑缺血大鼠的血管生成,mi R-429可作为治疗缺血性脑卒中的新靶点。

Objective To investigate the mechanism of mi R-429 on angiogenesis in ischemic stroke induced by hypoxia. Method The permanent focal cerebral ischemia rat model was established by thread embolism method, and they were randomly divided into four groups for different treatment ：（1） antagomi R-Ctr group： aerobic preconditioning and injection of antagomi R-Ctr;（2） antagomi R-429 group： aerobic preconditioning andinjection of antagomi R-429;（3） Co Cl2＋antagomi R-Ctr group： Co Cl2 pretreatment and injection of antagomi R-Ctr;（4） Co Cl2＋antagomi R-429 group： Co Cl2 pretreatment and injection of antagomi R-429. The doses of Co Cl2 solution and antagomi R-Ctr/429 were respectively30 mg·kg-1 and 12 mg·kg-1. The expressions of HIF-1α, VEGF and mi R-429 in each group were detected by Real-time Quantitative PCR Detecting System（QPCR） and Western blot, and the microvessel density and infarct volume were detected by fluorescein isothiocyanate-Dextran（FITC-Dextran） and triphenyltetrazolium chloride（TTC） staining. Results On the 7 th and 21 st day after cerebral ischemia, Co Cl2 pretreatment and antagomi R-429 induced the expression of hypoxia-inducible factor-1α（HIF-1α） and VEGF, reduced the expression of mi R-429, promoted angiogenesis and reduced infarct volume. Compared with the other three groups, Co Cl2 ＋ antagomi R-429 group had the highest expression of HIF-1α and VEGF, the lowest expression of mi R-429, the largest microvessel density and the smallest infarction volume on the 7 th day after cerebral ischemia,and the trend was more obvious on the 21 st day after cerebral ischemia. Conclusion Antagomi R-429 promotes angiogenesis in ischemic stroke induced by hypoxia, and mi R-429 may be a new target for the treatment of ischemic stroke.