caspase-12-siRNA预处理对小鼠肺缺血再灌注损伤的影响

Effect of small interfering RNA targeting caspase-12 pretreatment on lung ischemia/reperfusion injury in mice

目的 评价caspase-12靶向小干扰RNA（caspase-12-siRNA）预处理对小鼠肺缺血再灌注损伤的影响.方法 C57BL/6J雄性小鼠40只,6～8周龄,体重16～24 g,采用随机数字表法,将其分为4组（n=10）：假手术组（S组）、缺血再灌注组（IR组）、阴性对照组（NC组）和caspase-12-siRNA预处理组（siRNA组）.IR组、NC组和siRNA组采用夹闭左肺门30 min,再灌注3h的方法制备肺缺血再灌注损伤模型.造模前48 h时,NC组滴鼻法给予阴性对照siRNA 20μg,siRNA组滴鼻法给予caspase-12-siRNA 20 μg,总体积50μl.再灌注3h时,处死小鼠,取肺组织,测定肺湿重/干重比值（W/D比值）和肺水含量,光镜下观察病理学结果,计算肺泡损伤定量评估指数（QEI）和细胞凋亡指数,电镜下观察超微结构.结果 与S组比较,IR组和NC组肺W/D比值、肺含水量、肺泡损伤QEI和细胞凋亡指数均升高,siRNA组肺泡损伤QEI和细胞凋亡指数升高（P＜0.05）；与IR组和NC组比较,siRNA组肺W/D比值、肺含水量、肺泡损伤QEI和细胞凋亡指数均降低（P＜0.05）,病理学损伤减轻；IR组和NC组上述各指标比较差异无统计学意义（P＞0.05）.结论 caspase-12-siRNA预处理可减轻小鼠肺缺血再灌注损伤.

Objective To evaluate the effect of small interfering RNA targeting caspase-12 （caspase-12-siRNA） pretreatment on lung ischemia/reperfusion （I/R） injury in mice.Methods Forty male C57BL/6J mice,aged 6-8 weeks,weighing 16-24 g,were randomly allocated into 4 groups （n =10 each） using a random number table：sham operation group （group S）,group I/R,negative control group （group NC） and caspase-12-siRNA pretreatment group （group siRNA）.Lung I/R was induced by clamping the left pulmonary hilum for 30 min followed by 3 h reperfusion in anesthetized mice in IR,NC and siRNA groups.At 48 h before ischemia,negative control siRNA 20 μg and caspase-12-siRNA 20 μg were instilled intranasally in NC and siRNA groups,respectively,and the total volume was 50 μl.At 3 h of reperfusion,the animals were sacrificed and the left lung was removed for determination of wet/dry lung weight （W/D） ratio and lung water content in lung tissues and for microscopic examination.Pulmonary ultrastructure was examined with electron microscope.The quantitative evaluation index （QEI） for alveolar damage and apoptosis rate were calculated.Results Compared with group S,W/D ratio,lung water content,QEI for alveolar damage and apoptosis index were significantly increased in IR and NC groups,QEI for alveolar damage and apoptosis index were increased in group siRNA （P 〈 0.05）.Compared with IR and NC groups,W/D ratio,lung water content,QEI for alveolar damage and apoptosis index were significantly decreased （P 〈 0.05）,and the pathological changes of lungs were alleviated in group siRNA.There was no significant difference in the indices mentioned above between groups IR and NC （P 〉 0.05）.Conclusion Caspase-12-siRNA pretreatment can attenuate lung I/R injury in mice.