miR-17在动脉粥样硬化中下调ATG7蛋白水平抑制巨噬细胞的自噬功能

摘要

Objective To measure the levels of autophagy related miRNAs in the serum of atherosclerosis patients,and investigate whether these miRNAs is involved in the autophagy in macrophage and further affects the cytokine expression and apoptosis of macrophage.Methods The levels of autophagy related miRNAs in the serum of atherosclerosis patients were analyzed by real-time quantitative PCR.The expression of ATG7 and LC3 Ⅱ measured by Western blotting after transfecting macrophage with miR-17.Moreover,the damage of macrophage induced by H2 O2 was analyzed by MTT assay and the cytokine expression of macrophage was further measured by real-time quantitative PCR.Results miR-17 level was specifically up-regulated in serum of atherosclerosis patients.Additionally,the expression miR-17 targeted protein,ATG7 and the marker of autophagy,LC3 Ⅱ was reduced in macrophage after miR-17 transfectrion.Moreover,miR-17 enhanced the cytokine expression and promoted the apoptosis of macrophage induced by H2O2.Conclusion In serum of atherosclerosis patients,the level of miR-17 was fund specifically up-regulated.And elevated level of miR-17 in macrophage reduced the expression of ATG7 to inhibit autophagy,which sequentially enhanced the cytokine expression and promote the macrophage apoptosis.%目的 在动脉粥样硬化患者的血液中检测自噬相关miRNA的水平变化,探究差异miRNA是否参与巨噬细胞的自噬过程,并影响巨噬细胞的凋亡及炎症表达.方法 在动脉粥样硬化患者的血液中,用荧光定量PCR的方法检测miRNA的水平.在转染miR-17后,通过蛋白质免疫印迹的方法检测巨噬细胞中ATG7蛋白以及自噬标志物LC3Ⅱ表达.同时,使用MTT实验检测转染miR-17后双氧水诱导巨噬细胞凋亡的改变,通过荧光定量PCR检测炎性因子水平探究转染miR-17后巨噬细胞的炎症表达.结果 在动脉粥样硬化患者的血液中,miR-17的水平特异升高.而转染miR-17后,巨噬细胞中miR-17靶向蛋白ATG7和自噬标志物LC3Ⅱ表达下降.miR-17在巨噬细胞中的升高同时促进了双氧水诱导的细胞凋亡,并增强了TNF-α等炎性因子的表达.结论 miR-17水平在动脉粥样硬化患者的血液中特异升高,并在巨噬细胞通过靶向ATG7介导细胞自噬水平降低,进而增强巨噬细胞的炎症表达并促进其凋亡.