【摘要】 目的探究间歇低氧(IH)条件下引起小鼠血管内皮功能障碍的机制。方法呼吸仿真系统构建IH暴露模型,将60只C57BL/6J雄性小鼠随机分为对照组和IH组。IH组每天低氧暴露8 h,持续6周。应用酶联免疫吸附法(ELISA)测定小鼠血清低氧诱导因子-1a(HIF-1a)和基质细胞衍生因子-1a(SDF-1a)的水平;测定2组小鼠血清中活性氧簇(ROS)的水平;运用实时荧光定量PCR检测2组小鼠血清中mi R-199a-5p的表达量;应用双荧光素酶报告系统及点突变试验对HIF-1a进行靶基因验证。结果与对照组相比,IH组小鼠HIF-1a(μg/L:1.60±0.02 vs.1.19±0.02)、SDF-1a(ng/L:1 823.00±8.97 vs.1 444.00±17.90)的水平明显升高(P<0.01);ROS水平明显高于对照组(U/m L:487.66±35.73 vs.211.57±23.82,P<0.01);IH组的血清mi R-199a-5p水平低于对照组(1.31±0.07 vs.3.47±0.17,P<0.01);双荧光素酶报告基因检测结果证实HIF-1a为mi R-199a-5p的靶基因。结论 IH可引起小鼠血清mi R-199a-5p水平的下降,其靶基因HIF-1a继而升高,而HIF-1a可引起SDF-1a升高,SDF-1a的受体——细胞膜半胱氨酸-X-半胱氨酸受体-4(CXCR4)随之增加,最终引起血清ROS水平升高,导致血管内皮功能障碍。更多还原

【Abstract】 Objective To explore the mechanism of vessel endothelial dysfunction in rats under intermittent hypoxia(IH). Methods The respiratory simulation system was used to simulate IH. Sixty C57BL/6J rats(male) were randomizedinto control group and IH group. The rats of IH group were exposed to IH 8 hours per day for 6 weeks. The serum levels ofhypoxia inducible factor(HIF)-1a and stromal cell derived factor(SDF)-1a were assessed by ELISA. The serum levels ofreactive oxygen species(ROS) were detected in two groups. The serum expression of mi R-199a-5p was detected by real-time fluorescent quantitative PCR in two groups. The dual luciferase report system and point mutation test were used to verifytarget gene for HIF-1a. Results The serum levels of HIF-1a and SDF-1a were significantly higher in IH group thanthose of control group(μg/L: 1.60±0.02 vs. 1.19±0.02, 1 823.00±8.97 vs. 1 444.00±17.90, P<0.01). The serum level of ROSwas significantly higher in IH group than that of control group(U/m L: 487.66±35.73 vs. 211.57±23.82, P<0.01). The serumlevel of mi R-199a-5p expression was significantly lower in IH group compared to that of control group(1.31±0.07 vs. 3.47±0.17, P<0.01). The result of dual luciferase reporter gene detection confirmed that target gene of mi R-199a-5p was HIF-1a. Conclusion The serum level of mi R- 199a-5p is decreased first due to IH, and then its target gene(HIF- 1a) isincreased. HIF-1a can induce the increased level of SDF-1a, and its receptor(CXCR-4) is also increased. Finally, HIF-1a can increase the serum level of ROS, resulting in the endothelial dysfunction.更多还原