IL-6/STAT3信号通路在脓毒症所致骨骼肌消耗中的作用机制研究  

Mechanism of IL-6/STAT3 signaling pathway in sepsis induced skeletal muscle wasting

作　　者：黄利民 徐源佑 王璐璐 陈鑫玥 段婷 陆国玉[1,2] HUANG Li-min;XU Yuan-you;WANG Lu-lu;CHEN Xin-yue;DUAN Ting;LU Guo-yu(Department of Emergency Surgery,the First Affiliated Hospital of Bengbu Medical College,Bengbu 233000,Anhui,China;Department of Emergency Medicine,Jinling Hospital,Medical School of Nanjing University,Nanjing 210002,Jiangsu,China)

机构地区：[1]蚌埠医学院第一附属医院急诊外科,安徽蚌埠233000 [2]南京大学医学院附属金陵医院/东部战区总医院急诊医学科,江苏南京210002

出　　处：《肠外与肠内营养》2023年第6期368-374,共7页Parenteral & Enteral Nutrition

基　　金：安徽省教育厅科学研究项目(伦科批字[2022]第191号)。

摘　　要：目的:探索IL-6/STAT3信号通路在腹腔脓毒症所导致的骨骼肌消耗中的具体作用及机制。方法:10周龄SPF级C57BL/6健康雄性小鼠随机分为对照组(假手术组)和盲肠结扎穿孔制备腹腔脓毒症组后,在脓毒症组内随机分为对照脓毒症组、脓毒症+抗IL-6单抗组以及脓毒症+酪氨酸激酶抑制剂AG490组,以观察阻断IL-6信号通路对脓毒症小鼠骨骼肌消耗的影响。实验周期为72 h,抗IL-6单抗组及AG490的给药方式均为腹腔注射,每24小时给药一次。实验结束后留取小鼠的双侧后肢背侧腓肠肌,称重后制作骨骼肌冰冻切片。免疫荧光染色检测小鼠骨骼肌层粘连蛋白(Laminin蛋白),并检测小鼠骨骼肌纤维横截面积。q-PCR以及Western Blot方法检测小鼠骨骼肌萎缩和炎症相关蛋白表达。结果:与对照组(假手术组)相比,脓毒症小鼠的IL-6信号通路显著激活,表现为建模后24 h、48 h以及72 h的IL-6水平及p-STAT3/STAT3比值显著升高(P<0.05),而骨骼肌肌球蛋白重链(MYHC)含量显著下降(P<0.05)。通过腹腔注射抗IL-6单抗组或者AG490阻断IL-6/STAT3信号通路,可显著的增加小鼠的体质量及腓肠肌重量(P<0.05),且增加小鼠的骨骼肌平均肌纤维面积及骨骼肌平均纤维直径(P<0.01),并显著的降低骨骼肌组织中萎缩相关基因Murf-1(P<0.05)和Atrogin-1(P<0.05)的表达。同时,小鼠的骨骼肌MYHC蛋白表达量均显著增加(P<0.01)。结论:脓毒症状态下,IL-6升高导致的IL-6/STAT3信号通路激活是导致骨骼肌组织萎缩的重要原因之一。通过增加IL-6的清除,或者阻断IL-6的细胞内信号传导途径,可有效的改善脓毒症小鼠的骨骼肌消耗情况。Objective:To explore the specific role and mechanism of IL-6/STAT3 signaling pathway in skeletal muscle wasting caused by abdominal sepsis.Method:SPF C57BL/6 healthy 10-week-old male mice were randomly divided into control group(sham operation group)and abdominal sepsis group(by cecum ligation and puncture).After that,sepsis group was randomly divided into control sepsis group,sepsis+anti-IL-6 monoclonal antibody group and sepsis+tyrosine kinase inhibitor AG490 group.The experimental period was 72 hours.The anti-IL-6 monoclonal antibody group and AG490 were administered by intraperitoneal injection every 24 hours.The mice were euthanized and both gastrocnemius muscles were removed 24 hours after the last injection.The laminin distribution in the muscles was assessed following immunofluorescence staining,and the cross-sectional area were assessed.q-PCR and Western Blot was used to measure the expression of proteins related to atrophy and inflammation in skeletal muscle.Results:Compared with the control group(sham operation group),the IL-6 signaling pathway was significantly activated in sepsis mice,as IL-6 levels and p-STAT3/STAT3 ratio were significantly increased at 24,48,and 72 hours after CLP performing(P<0.05),while MYHC content was significantly decreased(P<0.05).IL-6/STAT3 signaling pathway blocking by injection of anti-IL-6 monoclonal antibody or AG490 could significantly increase body weight and gastrocnemius muscle weight(P<0.05),and also increase the mean muscle fiber areas and mean muscle fiber diameters compared with those in the sepsis group(P<0.01).In addition,the atrophy-related gene expression of Murf-1 and Atrogin-1 in the IL-6 blocking group was significantly lower than that in the sepsis group(P<0.05),while the protein expression of MYHC in skeletal muscle was significantly increased(P<0.01).Conclusion:In sepsis,activation of IL-6/STAT3 signaling pathway caused by IL-6 elevation plays a pivotal role in skeletal muscle atrophy.Increasing the clearance or blocking the intracellular signaling path

关 键 词：脓毒症 骨骼肌消耗 白介素-6 炎症因子 

分 类 号：R459.7[医药卫生—急诊医学]