NLRP3炎症小体在ICU获得性衰弱大鼠呼吸肌和下肢肌中的表达

Expression and role of NOD-like receptor thermal-protein domain-related protein 3 inflammasome in skeletal muscles of rats with ICU-acquired weakness

目的探讨重症监护室获得性衰弱(ICU-AW)大鼠吸肌和下肢肌组织中NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎症小体的表达及作用。方法将40只健康雄性SD大鼠完全随机分为对照组(sham组)和实验组(脓毒血症组),采用盲肠结扎穿孔术在实验组大鼠中构建ICU-AW模型,对照组仅行开腹暴露盲肠手术;造模96 h后收集大鼠腓肠肌和膈肌标本,采用HE染色观察病理学变化并计算肌纤维横截面积,采用qRT-PCR和western blot的方法检测大鼠腓肠肌和膈肌中Atrogin-1、MuRF1、NLRP3、Caspase-1、IL-1β和IL-18的表达。结果盲肠结扎穿孔术96 h后,大鼠腓肠肌和膈肌纤维排列较对照组疏松,肌纤维横截面积较对照组明显减少(P<0.05),Atrogin-1、MuRF1基因和蛋白表达量较对照组明显升高(P<0.05);ICU-AW大鼠腓肠肌和膈肌中NLRP3、Caspase-1、IL-1β和IL-18基因和蛋白表达量较对照组明显升高(P<0.05)。结论盲肠结扎穿孔术制备的脓毒血症模型中,吸肌和下肢肌溶解参与ICU-AW的发生,NLRP3炎症小体相关信号通路参与上述过程。

Objective To investigate the expression and role of NOD-like receptor thermal-protein domain-related protein 3(NLRP3)inflammasome in the skeletal muscles of the rats with Intensive Care Unit-acquired weakness(ICU-AW).Methods Forty healthy male Sprague-Dawley rats were randomly divided into a control group(the sham group)and an experimental group(a septic group).The ICU-AW models were established by cecal ligation and puncture,while cecal exposure but no ligation or puncture was carried out in the rats of the control group.The gastrocnemius and diaphragmatic muscle specimens were collected 96 h after modeling.The pathological changes were observed by HE staining and the cross-sectional areas of the muscle fibers were calculated and compared between the two groups.Both gene and protein expressions of atrogin-1,MuRF1,NLRP3,caspase-1,IL-1βand IL-18 in the gastrocnemius and diaphragmatic muscle were detected by qRT-PCR and Western blotting method.Results The arrangement of the gastrocnemius and diaphragm muscle fibers was looser 96 h after cecal ligation and puncture compared with that of the controls.And the cross-sectional areas of the muscle fibers from the experimental group were significantly smaller than those of the controls(P<0.05).Both gene and protein expression levels of atrogin-1 and MuRF1 were higher in the muscle samples from the ICU-AW rats than those of the controls(P<0.05).NLRP3 inflammatory body-related molecular studies showed that the expression levels of NLRP3,caspase-1,IL-1βand IL-18 in the gastrocnemius and diaphragmatic muscle of the ICU-AW rats were significantly higher than those of the controls(P<0.05).Conclusion Skeletal muscle lysis participates in the occurrence of ICU-AW in the rat models created by cecal ligation and puncture,and NLRP3 inflammasome-related signal pathway participates in the above process.