miR-146a促进动脉粥样硬化斑块形成调控机制研究

Mechanism in regulation of miR-146a promoting atherosclerotic plaque formation

目的探讨miR-146a对动脉粥样硬化斑块的影响及其机制。方法利用miR-146a增强剂(miR-146a mimic)和miR-146a拮抗剂(miR-146a inhibitor)转染大鼠外周血单核巨噬细胞,转染成功后予巨噬细胞泡沫化。油红O染色和脂质染色的半定量分析miR-146a对细胞的脂质堆积情况的影响。Western blot检测胆固醇酯水解酶(cholesteryl ester hydrolase,CEH)、ABCA1和ABCG1的表达情况。结果 Western blot检测显示,miR-146a mimic转染组的CEH表达明显降低,miR-146a inhibitor转染组的ABCA1和ABCG1表达量较对照组和miR-146a mimic转染组明显增多。油红O染色显示miR-146a mimic转染组、对照组和miR-146a inhibitor转染组的阳性细胞比例分别为82.1%±3.1%、73.2%±0.16%和16.25%±2.1%。结论miR-146a能够抑制大鼠外周血单核巨噬细胞细胞内CEH的表达,进而阻碍游离胆固醇的外流,最终导致动脉粥样硬化斑块的形成。

Objective To study the effect and mechanism of miR-146a in atherosclerotic plaque. Methods Rat monocyte macrophages were transfected with agomir-146a （miR-146a mimic） and antagomir-146a （miR-146a inhibitor）, and exposed to ox- LDL after transfection. Macrophages were stained with oil red O and semi-quantitative analysis were used to evaluate the effect of miR-146a on lipid accumulation. Western blot was employed to detect the expression of CEH, ABCA1 and ABCG1. Results Western Blot showed that the expression of CEH significantly decreased in miR-146a mimics, while the expression of ABCA1 and ABCG1 in miR-146a inhibitor transfection group increased much more than they were in the control group and miR-146a mimic transfection group. Oil Red O staining showed that the positive cells ratios in miR-146a mimic transfection group and control group and miR-146a inhibitor transfected group were 82.1% ± 3.1%, 73.2% ± 0.162% and 16.25% ± 2.1% respectively. Conclusion miR- 146a can inhibit the expression of CEH in rat peripheral blood mononuclear cells and hinder cholesterol efflux, thus resulting in atherosclerotic plaque formation.