目的:观察慢病毒介导的亲环素A(cyclophilin A,CyPA)小干扰RNA对载脂蛋白E基因敲除( ApoE^-/-)小鼠动脉粥样斑块的影响。方法采用ApoE^-/-小鼠颈动脉硅胶圈置入法快速建立动脉粥样斑块模型,然后将小鼠分为CyPA小干扰RNA慢病毒载体治疗组( CyPA-RNAi-LV组)和绿色荧光蛋白-慢病毒载体对照组(NC-GFP-LV组),采用局部注射法将10μl(1.0×108 TU/ml)慢病毒载体局部作用硅胶圈置入处10 min,干预ApoE^-/-小鼠颈动脉斑块。采用苏木素-伊红染色法观察各组小鼠动脉粥样斑块大小。采用实时聚合酶链反应( RT-PCR)法检测各组小鼠动脉粥样硬化斑块中CyPA mRNA的表达水平,Western blot法检测其蛋白水平。结果转染6周后,CyPA-RNAi-LV组小鼠动脉粥样硬化斑块进展慢于NC-GFP-LV组,斑块面积分别为(9085±671)μm^2(18021±1901)μm^2两组比较差异有统计学意义(P<0.05),斑块中脂质含量较NC-GFP-LV组少[(17.8±4.5)%比(28.9±6.3)%, P<0.05],胶原含量较NC-GFP-LV组多[(35.1±5.2)%比(24.2±4.8)%, P<0.05],内膜/中膜比值NC-GFP-LV组较高(0.65±0.12比0.36±0.11,P<0.05),管腔狭窄较NC-GFP-LV组轻(内膜/管腔比值,0.18±0.02比0.33±0.03, P<0.05)。 CyPA-RNAi-LV组小鼠促炎因子和基质金属蛋白酶表达水平均较NC-GFP-LV组低( P均<0.05)。结论慢病毒介导的CyPA小干扰RNA能抑制ApoE^-/-小鼠动脉粥样硬化斑块的进展,减轻斑块局部炎症反应。
Objective The aim of this study was to determine whether inhibition of cyclophilin A by lentivirus-mediated RNA interference ( RNAi ) could inhibit progression of atherosclerotic plaques and increase collagen production .Methods Atherosclerostic plaque model was induced by rapid perivascular carotid silicone collar placement in ApoE -/-mice.The recombinant CyPA-RNAi-Lentivirus ( CyPA-RNAi-LV) or negative control-green fluorescent protein-Lentivirus ( NC-GFP-LV) were constructed and transfected into right carotid plaques , respectively.Using the local injection method , ApoE^-/- mice carotid artery plaque were intervened 10 min in the silicone collar placement with 10 μl ( 1.0 ×108 TU/ml ) lentivirus vector.The areas and CyPA expression of plaques were analyzed by morphological observation , real-time polymerase chain reaction ( RT-PCR ) and Western blot respectively .Results CyPA-RNAi-LV not only prevented plaques progression ((9 085 ±671) μm2 to (18 021 ±1 901) μm2), but also decreased plaque lipid content ((28.9 ±6.3)%to (17.8 ±4.5)%), increased plaque collagen content ((24.2 ±4.8)%to (35.1 ±5.2)%) at 6 weeks after lentivirus transfection.The intima/media ratio (0.36 ±0.11 vs.0.65 ±0.12, P〈0.05) and degree of lumen stenosis (intima/lumen ratios, 0.18 ±0.02 vs.0.33 ±0.03, P〈0.05 ) were also significantly reduced by CyPA-RNAi-LV.Moreover , RT-PCR analysis revealed downregulated expressions of proinflammatory cytokines and matrix metalloproteinases ( MMP-9 -17.5%) in the CyPA-RNAi-LV group.Conclusion Lentivirus-mediated CyPA silencing by siRNA could inhibit plaques progression and reduce local inflammation through the anti-inflammatory effects in this model .