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

摘要

Objective To investigate the mechanism of miR-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 :①antagomiR-Ctr group: aerobic preconditioning and injection of antagomiR-Ctr;②antagomiR-429 group: aerobic preconditioning and injection of antagomiR-429;③CoCl2+antagomiR-Ctr group: CoCl2 pretreatment and injection of antagomiR-Ctr; ④CoCl2+antagomiR-429 group: CoCl2 pretreatment and injection of antagomiR-429. The doses of CoCl2 solution and antagomiR-Ctr / 429 were respectively30mg·kg-1 and 12mg·kg-1. The expressions of HIF-1α, VEGF and miR-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 7th and 21st day after cerebral ischemia, CoCl2 pretreatment and antagomiR-429 induced the expression of hypoxia-inducible factor-1α(HIF-1α) and VEGF, reduced the expression of miR-429, promoted angiogenesis and reduced infarct volume. Compared with the other three groups, CoCl2 + antagomiR-429 group had the highest expression of HIF-1α and VEGF, the lowest expression of miR-429, the largest microvessel density and the smallest infarction volume on the 7th day after cerebral ischemia,and the trend was more obvious on the 21st day after cerebral ischemia.Conclusion AntagomiR-429 promotes angiogenesis in ischemic stroke induced by hypoxia, and miR-429 may be a new target for the treatment of ischemic stroke.%目的 探讨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.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:①antagomiR-Ctr组:常氧预处理并注射antagomiR-Ctr;②antagomiR-429组:常氧预处理并注射antagomiR-429;③CoCl2+antagomiR-Ctr组:CoCl2预处理并注射antagomiR-Ctr;④CoCl2+antagomiR-429组:CoCl2预处理并注射antagomiR-429.CoCl2溶液和antagomiR-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miR-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,CoCl2预处理和antagomiR-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miR-429的表达,并促进血管生成和缩小梗死体积;脑缺血后第7d,CoCl2+antagomiR-429组较其余3组HIF-1α和VEGF的表达最高,miR-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 AntagomiR-429促进低氧诱导的脑缺血大鼠的血管生成,miR-429可作为治疗缺血性脑卒中的新靶点.