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

Abstract

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. Key words: Caspase-12 ; RNA, small interfering ; Ischemic preconditioning ; Reperfusion injury ; Lung