小分子RNA沉默间隙连接蛋白37对猪腹主动脉粥样斑块的影响

Effects of small interfering RNA interference of connexin 37 on atherosclerotic plaque in pigs

目的建立猪动脉粥样硬化斑块模型，构建猪靶向小干扰RNA（siRNA）慢病毒载体，定向转染后用血管内超声（IVUS）分析斑块特性变化。方法60只猪建立动脉粥样硬化模型，间隙连接蛋白37（Cx37）siRNA慢病毒悬液、mock—siRNA、生理盐水分别注入斑块，2个月后用血管内超声检测斑块体积和组织成分，并与干预前比较。同时检测斑块Cx37 mRNA及Cx37蛋白表达．并行组间比较。结果慢病毒转染2个月后，猪腹主动脉斑块Cx37 mRNA水平在Cx37 siRNA组下降到34％，mock—siRNA组下降到61％，生理盐水组下降到94％（P〈0．05），其中Cx37 siRNA组显著下降。Western blot分析显示Cx37蛋白表达水平在Cx37siRNA干扰组较其他组低（0．21±0．07、0．65±0．06、0．54±0．07）。IVUS检测，10个月时斑块坏死核心占比率较8个月时[降低（5．26±2．11）％比（7．83±1．03）％，P〈0．05]。Cx37 siRNA组斑块体积较8个月时减小[（21．03±6.24）mm^3比（31．23±10．23）mm^3，P〈0．01]。而mock—siRNA和生理盐水组，斑块体积较8个月时增大[（38．54±13．56）mm^3比（32．12±11．21）mm^3，（37．36±14．21）mm^3比（30．21±12．02）mm^3，P〈0．05]。结论Cx37 siRNA安全有效作用于动脉粥样硬化斑块，有效地减少Cx37 mRNA和蛋白表达，并促进斑块稳定及缩小斑块。

Objective To construct lentiviruses targeting pig connexin 37 （Cx37） small interfering RNA （siRNA） and establish pig atherosclerosis plaque model, and observe the plaque characteristics by intravenous ultrasound （IVUS） after directional transfection of the lentiviruses into into carotid lesions. Methods The plaque models of 60 pigs fed on high-fat diet were established. The pigs were randomly divided into the saline, mock-siRNA, Cx37 siRNA groups, undergoing transfection of saline, mock-siRNA and Cx37 viral suspension into the abdominal aorta plaques respectively. Two months later, IVUS was used to measure the plaque size and the composition. Simultaneously, the expression of Cx37 mRNA and protein in the plaques was detected. Results Two months after lentivirus transfection, Cx37 mRNA levels in the Cx37 siRNA group, mock-siRNA group and saline group were reduced by 34% , 61% , and 94% respectively （ P 〈 0. 05 ）. Western blotting analysis showed that Cx37 protein was lower in Cx37-RNAi group than in other groups （0. 21 ± 0. 07 vs. 0. 65 ± 0. 06 vs. 0. 54±0. 07）. The plaque necrosis on 10-month percentages was decreased in Cx37 siRNA group as compared with 8-month percentages （5.26 ± 2. 11 vs. 7.83 ± 1. 03% ,P 〈0. 05 ）. In Cx37 siRNA group, plaque volume was decreased relative to the 8-month percentages （21.03 ± 6. 24 vs. 31.23 ± 10. 23,P 〈 0. 01 ）. By contrast, plaque volume was increased relative to their 8-month percentages [（38.54 ± 13.56） mm^3 vs. （32. 12 ± 11.21） mm^3, and （37.36 ± 14.21） mm^3 vs. （30.21 ± 12.02） mm^3,P〈0.05] in mock-siRNA and saline groups. Conclusion By IVUS, Cx37 siRNA exerts an effect on atherosclerotic plaques, and interference of Cx37 reduces the Cx 37 mRNA experssion and decreases the plaques effectively.