宫内注射脂多糖对围产期大鼠肺Toll样受体4信号转导通路的影响  

Effect of intrauterine lipopolysaccharide infusion on Toll-like receptor 4 signaling transduction pathway in lungs of perinatal rats

作　　者：余肖[1] 肖彩菊[1] 戴红梅[1] 王伟[1] 蒙晶[1] 章晓婷[1] 宁琴[1] 罗小平[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院儿科,武汉430030

出　　处：《中华儿科杂志》2009年第9期667-671,共5页Chinese Journal of Pediatrics

基　　金：基金项目：国家自然科学基金资助项目（30672262）;卫生部临床学科重点项目（卫规财函2007-353）

摘　　要：目的观察宫内注射脂多糖（LPS）对围产期大鼠肺内天然免疫相关的Toll样受体4（TLR4）信号转导通路的影响，探讨天然免疫在宫内感染中的免疫调节能力及对肺发育的影响。方法将30只孕17d的SD大鼠随机分为LPS组和生理盐水对照组，LPS组宫内注射LPS10出（40μg/ml），对照组宫内注射等体积的灭菌生理盐水。分别留取胎龄18、20、22d（E18、E20、E22）的胎鼠肺组织、胎盘组织标本以及生后1、3、7d（P1、P3、P7）新生鼠肺组织标本，HE染色观察病理改变，RT-PCR技术检测TLR4、髓样分化因子88（MyD88）和白介素1B（IL-1B）mRNA表达，免疫组织化学技术检测肺组织TLR4、MyD88的表达分布情况。实验数据采用单因素方差分析和q检验进行统计学分析。结果（1）LPS组孕鼠胎盘组织有大量中性粒细胞浸润，宫内感染模型建立成功；（2）在E18、E20和E22时，LPS组胎鼠肺组织无明显病理学改变，以后逐渐出现改变，于P7时可见肺泡数量减少，肺泡腔变大，间隔变薄，但未见明显结构紊乱；（3）LPS组TLR4、MyD88和IL-1βmRNA水平于E20和E22均高于对照组，差异有统计学意义（P〈0．05），且均于E22表达达高峰，后缓慢下降；（4）免疫组织化学结果显示E18时两组肺组织内均未见明显TLR4和MyD88阳性染色，后均逐渐表达增加，且主要在细支气管和肺泡上皮细胞表达。结论（1）宫内注射LPS可导致胎鼠和早产鼠肺组织TLR4、MyD88表达在一定范围内增加，后逐渐回复正常水平，同时肺组织的病理改变和炎症反应较为温和，推测在围产期胎肺天然免疫系统可以调节LPS诱导的炎症反应强度；（2）该实验在一定程度上证实宫内感染激活的信号转导通路是MyD88依赖性途径。Objective To investigate the influence of intrauterine infection caused by lipopolysaccharide on Toll-like receptor 4 （TLR4） signaling pathway in fetal and neonatal rat lungs in order to explore immunomodulating activity of innate immunity responding to intrauterine infection and its effect on lung development. Methods On day 17 of pregnancy, 30 pregnant Sprague-Dawley （SD） rats were randomly divided into two groups： LPS group and saline group. For LPS group, LPS （10 μl, 40 μg/ml） was intrauterine injected between every two embryonic sacs of the pregnant rats, while the rats in the control group were injected with the same volume of pyrogen-free saline. Lung tissues of fetal rats and corresponding placental tissues were collected on the embryonic day 18 （E18） , E20, and E22. Neonatal lung tissues were also harvested on postnatal day 1 （ P1 ）, P3, and P7. Lung sections and placental tissues were stained with hematoxylin and eosin for histological examination. Reverse transcription quantitative polymerase chain reaction （RT-PCR） analysis was performed to test mRNA expression for TLR4, myeloid differentiation 88 （ MyD88 ） and IL-1β, while immunohistochemistry was used to evaluate TLR4 and MyD88 expression in lung tissues. All data were analyzed with one-way analysis of variance （ANOVA） and q test. Results （ 1 ） Placental hematoxylin-eosin staining showed a great number of neutrophils infiltration, obvious interstitial hyperplasia and narrow capillaries in placental tissues in the LPS group which indicated that intrauterine infection occurred. However, there were no obvious inflammatory cells in the control group. （2） On E18, E20 and E22, the lung of LPS group showed no obvious pathological changes, and there were no apparent neutrophils infiltrated in alveoli, then some structural changes appeared. On PT, we found that the number of alveoli decreased, space of alveoli was larger than ever, septa thickened, but without significant constructive disorder. （3） In the LPS

关 键 词：支气管肺发育不良 脂多糖类 TOLL样受体4 宫内感染 

分 类 号：R686[医药卫生—骨科学]