Promotion of new blood vessel formation is a new strategy for treating ischemic stroke.Non-coding miRNAs have been recently considered potential therapeutic targets for ischemic stroke.miR-181b has been shown to promo...Promotion of new blood vessel formation is a new strategy for treating ischemic stroke.Non-coding miRNAs have been recently considered potential therapeutic targets for ischemic stroke.miR-181b has been shown to promote angiogenesis in hypoxia and traumatic brain injury model,while its effect on ischemic stroke remains elusive.In this study,we found that overexpression of miR-181b in brain microvascular endothelial cells subjected to oxygen-glucose deprivation in vitro restored cell prolife ration and enhanced angiogenesis.In rat models of focal cerebral ischemia,ove rexpression of miR-181b reduced infarction volume,promoted angiogenesis in ischemic penumbra,and improved neurological function.We further investigated the molecular mechanism by which miR-181b participates in angiogenesis after ischemic stroke and found that miR-181b directly bound to the 3’-UTR of phosphatase and tensin homolog(PTEN) mRNA to induce PTEN downregulation,leading to activation of the protein kinase B(Akt) pathway,upregulated expression of vascular endothelial growth facto rs,down-regulated expression of endostatin,and promoted angiogenesis.Taken togethe r,these results indicate that exogenous miR-181b exhibits neuroprotective effects on ischemic stro ke through activating the PTEN/Akt signal pathway and promoting angiogenesis.展开更多
目的探讨miR-181b靶向调控肌肉过量蛋白-3B(muscle excess protein-3,Mex3B)的表达在动脉粥样硬化(atherosclerosis,AS)斑块的形成及其分子作用机制。方法将雄性SD大鼠随机分成正常组、模型组、对照组和实验组。对照组和实验组分别尾静...目的探讨miR-181b靶向调控肌肉过量蛋白-3B(muscle excess protein-3,Mex3B)的表达在动脉粥样硬化(atherosclerosis,AS)斑块的形成及其分子作用机制。方法将雄性SD大鼠随机分成正常组、模型组、对照组和实验组。对照组和实验组分别尾静脉注射miR-181b-inhibitor-NC、miR-181b-inhibitor的混合液,正常组、模型组注射等剂量的生理盐水;注射完毕24 h后将维生素D3以600000 U/kg的剂量一次性腹腔注射进模型组、对照组、实验组大鼠体内后,每日以100 g高脂饲料喂养构建AS模型大鼠,正常组大鼠始终以等量基础饲料喂养。喂养60 d后,对大鼠进行颈动脉超声检查,测量管腔动脉后壁内膜-中层厚度(intima-media thickness of the posterior wall of the artery,IMT)和斑块面积(square,S)参数。RT-PCR检测各组miR-181b和Mex3B蛋白的mRNA的表达;Western blot检测各组Mex3B蛋白的表达水平;荧光素酶报告基因分析miR-181b和Mex3B的调控关系。结果与正常组相比,模型组大鼠颈动脉内膜增生明显,颈动脉IMT、斑块S、miR-181b和Mex3B蛋白的mRNA和蛋白的表达明显增大,与模型组相比,实验组大鼠大鼠颈动脉内膜增生明显减小,颈动脉IMT、斑块S、miR-181b和Mex3B蛋白的mRNA和蛋白的表达明显减小,差异均具有统计意义(P<0.05)。荧光素酶报告基因分析证明miR-181b与Mex3B靶向结合。结论miR-181b通过靶向调控Mex3B的表达参与动脉粥样硬化中的炎性应激反应,抑制miR-181b的表达能明显抑制炎症反应,抑制AS中斑块的形成。展开更多
基金supported by the National Natural Science Foundation of China,Nos.81801169 (to LXX),82071404 (to HC),81870952 (to HMW)。
文摘Promotion of new blood vessel formation is a new strategy for treating ischemic stroke.Non-coding miRNAs have been recently considered potential therapeutic targets for ischemic stroke.miR-181b has been shown to promote angiogenesis in hypoxia and traumatic brain injury model,while its effect on ischemic stroke remains elusive.In this study,we found that overexpression of miR-181b in brain microvascular endothelial cells subjected to oxygen-glucose deprivation in vitro restored cell prolife ration and enhanced angiogenesis.In rat models of focal cerebral ischemia,ove rexpression of miR-181b reduced infarction volume,promoted angiogenesis in ischemic penumbra,and improved neurological function.We further investigated the molecular mechanism by which miR-181b participates in angiogenesis after ischemic stroke and found that miR-181b directly bound to the 3’-UTR of phosphatase and tensin homolog(PTEN) mRNA to induce PTEN downregulation,leading to activation of the protein kinase B(Akt) pathway,upregulated expression of vascular endothelial growth facto rs,down-regulated expression of endostatin,and promoted angiogenesis.Taken togethe r,these results indicate that exogenous miR-181b exhibits neuroprotective effects on ischemic stro ke through activating the PTEN/Akt signal pathway and promoting angiogenesis.
文摘目的探讨miR-181b靶向调控肌肉过量蛋白-3B(muscle excess protein-3,Mex3B)的表达在动脉粥样硬化(atherosclerosis,AS)斑块的形成及其分子作用机制。方法将雄性SD大鼠随机分成正常组、模型组、对照组和实验组。对照组和实验组分别尾静脉注射miR-181b-inhibitor-NC、miR-181b-inhibitor的混合液,正常组、模型组注射等剂量的生理盐水;注射完毕24 h后将维生素D3以600000 U/kg的剂量一次性腹腔注射进模型组、对照组、实验组大鼠体内后,每日以100 g高脂饲料喂养构建AS模型大鼠,正常组大鼠始终以等量基础饲料喂养。喂养60 d后,对大鼠进行颈动脉超声检查,测量管腔动脉后壁内膜-中层厚度(intima-media thickness of the posterior wall of the artery,IMT)和斑块面积(square,S)参数。RT-PCR检测各组miR-181b和Mex3B蛋白的mRNA的表达;Western blot检测各组Mex3B蛋白的表达水平;荧光素酶报告基因分析miR-181b和Mex3B的调控关系。结果与正常组相比,模型组大鼠颈动脉内膜增生明显,颈动脉IMT、斑块S、miR-181b和Mex3B蛋白的mRNA和蛋白的表达明显增大,与模型组相比,实验组大鼠大鼠颈动脉内膜增生明显减小,颈动脉IMT、斑块S、miR-181b和Mex3B蛋白的mRNA和蛋白的表达明显减小,差异均具有统计意义(P<0.05)。荧光素酶报告基因分析证明miR-181b与Mex3B靶向结合。结论miR-181b通过靶向调控Mex3B的表达参与动脉粥样硬化中的炎性应激反应,抑制miR-181b的表达能明显抑制炎症反应,抑制AS中斑块的形成。
