Wu Xiao-Yuan, Fan Wen-Dong, Fang Rong, Wu Gui-Fu
Division of Cardiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China.
J Cell Biochem. 2014 Nov;115(11):1928-36. doi: 10.1002/jcb.24864.
Increasing evidences have illuminated the fundamental role of inflammation in mediating all stages of atherosclerosis. miR-155, a typical multi-functional miRNA, has recently emerged as a novel component of inflammatory signal transduction in the pathogenesis of atherosclerosis. However, little is known about whether endothelial highly expressed miR-155 can regulate endothelial inflammation-related transcription factors and the predicted role of miR-155 as a negative feedback regulator in endothelial inflammation involved in atherosclerosis. Bioinformatics analysis showed that RELA (nuclear factor-κB p65) is a potential target gene of miR-155 and this was confirmed by a luciferase reporter assay. Our results show that microRNA-155 mediate endothelial inflammation and decrease NFкB p65 and adhesion molecule expression in TNFα-stimulated endothelial cells. Transfection with miR-155 significantly inhibited TNFα-induced monocyte adhesion to endothelium. Inhibition of miR-155 enhanced p65 level and endothelial inflammatory response which was counteracted through the depletion of P65 by Si-P65. On the other hand, knockdown of eNOS, another target of miR-155, while transfecting with miR-155 inhibitor resulted in more significant inflammatory response. miR-155 is highly expressed in TNFα treated HUVECs, deprived of endogenous p65 could reverse TNFα-induced upregulation of miR-155. Thus, TNFα induced miR-155 may serve as a negative feedback regulator in endothelial inflammation involved in atherosclerosis by targeting nuclear transcription factor P65. These results provide a rationale for intervention of intracellular microRNA as possible anti-atherosclerotic targets.
越来越多的证据表明炎症在动脉粥样硬化各阶段的介导过程中发挥着重要作用。miR-155是一种典型的多功能微小RNA，最近已成为动脉粥样硬化发病机制中炎症信号转导的新成分。然而，关于内皮细胞高表达的miR-155是否能调节内皮炎症相关转录因子以及miR-155作为动脉粥样硬化相关内皮炎症中负反馈调节因子的预测作用，目前知之甚少。生物信息学分析表明，RELA（核因子-κB p65）是miR-155的潜在靶基因，荧光素酶报告基因检测证实了这一点。我们的结果表明，微小RNA-155介导内皮炎症，并降低肿瘤坏死因子α刺激的内皮细胞中NFкB p65和黏附分子的表达。用miR-155转染可显著抑制肿瘤坏死因子α诱导的单核细胞与内皮细胞的黏附。抑制miR-155可提高p65水平和内皮炎症反应，而通过Si-P65耗尽P65可抵消这种反应。另一方面，敲低miR-155的另一个靶标内皮型一氧化氮合酶（eNOS），同时转染miR-155抑制剂会导致更显著的炎症反应。miR-155在肿瘤坏死因子α处理的人脐静脉内皮细胞（HUVECs）中高表达，去除内源性p65可逆转肿瘤坏死因子α诱导的miR-155上调。因此，肿瘤坏死因子α诱导的miR-155可能通过靶向核转录因子P65，在动脉粥样硬化相关的内皮炎症中作为负反馈调节因子发挥作用。这些结果为将细胞内微小RNA作为可能的抗动脉粥样硬化靶点进行干预提供了理论依据。
