肺泡巨噬细胞Toll样受体9-髓样分化因子88信号通路在呼吸机相关性肺损伤中的作用机制研究  

Role and mechanism of signal pathway mediated by Toll-like receptor 9-myeloid differentiation factor 88 in alveolar macrophages in ventilator-induced lung injury in rats

作　　者：戴惠军 潘灵辉[1] 林飞[1] 葛万运[1] 李玮[1] 贺盛[1] 

机构地区：[1]广西医科大学附属肿瘤医院麻醉科,南宁530021

出　　处：《中华危重病急救医学》2014年第5期289-293,共5页Chinese Critical Care Medicine

基　　金：国家自然科学基金（81060008）;广西研究生教育创新计划资助项目（YCSZ2012044）

摘　　要：目的 探讨肺泡巨噬细胞Toll样受体9（TLR9）-髓样分化因子88（MyD88）信号通路在呼吸机相关性肺损伤（VILI）中的作用.方法 清洁级SD大鼠30只,按随机数字表法将大鼠分为3组,每组10只.A组保留自主呼吸作为对照;B组给予正常潮气量（VT,7 mL/kg）机械通气4h;C组给予大VT（40 mL/kg）机械通气4h.机械通气结束时,透射电镜下观察大鼠Ⅱ型肺泡上皮细胞（AECⅡ）超微结构改变;测定肺组织湿/干质量（W/D）比值以及支气管肺泡灌洗液（BALF）中总蛋白、白细胞介素（IL-6、IL-1β）的浓度;用蛋白质免疫印迹试验（Western Blot）和逆转录-聚合酶链反应（RT-PCR）分别检测肺泡巨噬细胞TLR9、MyD88、核转录因子-κB（NF-κB）的蛋白及其mRNA表达.结果 A、B组大鼠AECⅡ细胞超微结构基本正常;C组AECⅡ胞质内板层小体、细胞膜、细胞核中的染色质及微绒毛等均有不同程度的损伤性改变.C组较A组、B组肺组织W/D比值（5.54±0.17比4.58±0.17、4.69±0.16）,BALF中总蛋白（g/L：6.33±0.61比0.45±0.05、0.47±0.04）、IL-6（μg/L：1.989±0.103比1.033±0.061、1.010±0.069）、IL-1β（ng/L：2.79±0.25比1.05±0.15、1.23±0.22）,肺泡巨噬细胞TLR9、MyD88、NF-κB的蛋白表达[TLR9（A值）：0.770±0.042比0.300±0.027、0.310±0.037,MyD88（A值）：0.950±0.091比0.560±0.082、0.580±0.084,NF-κB（A值）：1.020±0.076比0.740±0.052、0.700±0.076]均明显升高,差异有统计学意义（P＜0.05或P＜0.01）.B组肺泡巨噬细胞TLR9、MyD88、NF-κB的mRNA表达分别是A组的（1.13±0.32）倍、（1.18±0.33）倍、（1.11±0.22）倍,差异均无统计学意义（均P＞0.05）;C组肺泡巨噬细胞TLR9、MyD88、NF-κB的mRNA表达分别是A组的（8.66±0.69）倍、（6.41±0.53）倍、（5.29±0.71）倍,差异均有统计学意义（均P＜0.01）.结论 肺泡巨噬细胞TLR9-MyD88信号通路参与并介导了机械通气所致的肺损伤.Objective To investigate the role of Toll-like receptor9 （TLR9）-myeloid differentiation factor 88 （MyD88） signal pathway in alveolar macrophages in ventilator-induced lung injury （VILI）.Methods 30 adult male Sprague-Dawley （SD） rats were randomly assigned to three groups （with 10 rats in each group）.Group A was the control group,with spontaneous respiration after tracheostomy.Rats in group B received mechanical ventilation for 4 hours with normal tidal volume （VT） 7 ml/kg after tracheostomy,and group C rats received mechanical ventilation with VT 40 ml/kg for 4 hours.After termination of ventilation,examination with transmission electron microscopy was performed to observe the ultrastructure changes in alveolar epithelial cell type Ⅱ （AEC Ⅱ） of the lung.Lung wet/dry ratios （W/D） and total protein concentration,the concentration of interleukins （IL-6 and IL-1 β） in bronchoalveolar lavage fluid （BALF） were determined.The protein and mRNA expressions of TLR9,MyD88 and nuclear factor-κB （NF-κB） in alveolar macrophages were assayed by Western Blot and real-time reverse transcription-polymerase chain reaction （RT-PCR）.Results The ultrastructure of AEC Ⅱ in the group A and group B was almost normal,whereas the chromatin of the nuclei,the lamellar corpuscles in the cytoplasm,the cell membrane and the microvilli of the AEC Ⅱ in the group C showed injurious changes in various degrees.When the group C was compared with the group A and the group B,it was shown that the W/D ratios （5.54 ± 0.17 vs.4.58 ± 0.17,4.69 ± 0.16） and total protein concentration （g/L：6.33 ± 0.61 vs.0.45 ± 0.05,0.47 ± 0.04）,IL-6 （μg/L：1.989 ± 0.103 vs.1.033 ± 0.061,1.010 ± 0.069） and IL-lβ （ng/L：2.79 ±0.25 vs.1.05 ±0.15,1.23 ±0.22） in BALF,the protein expressions of TLR9,MyD88 and NF-κB [TLR9 （A value）：0.770 ±0.042 vs.0.300 ±0.027,0.310 ±0.037; MyD88 （A value）：0.950 ±0.091 vs.0.560 ±0.082,0.580±0.084; NF-κB（A value）：1.020 ±0.076 vs.0

关 键 词：肺泡巨噬细胞 机械通气 呼吸机相关性肺损伤 TOLL样受体9 髓样分化因子88 

分 类 号：R563.8[医药卫生—呼吸系统]