摘要
目的:全身炎症反应综合征(SIRS)是炎症介质过度释放的全身炎症反应,文中探讨严重烧伤和内毒素对在体SD大鼠肺泡巨噬细胞(AM)CD14基因表达的影响及调控作用以及体外培养AM的CD14膜蛋白表达对AM产生肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的影响及调控作用。方法:①在体部分:对20%Ⅲ度烧伤大鼠行外周血脂多糖(LPS)浓度检测。大鼠烧伤和LPS注射后在各时相点分别处死并分离提取AM,逆转录聚合酶链反应(RT-PCR)方法观察膜表面CD14mRNA表达变化。②体外部分:各组大鼠行全肺在体支气管肺泡灌洗(BAL)分离AM进行体外培养,分别加入烧伤血清、烧伤血清+抗体、内毒素、内毒素+抗体,用RT-PCR及ELISA方法分别检测4组AM在各时相点CD14mRNA表达及分泌TNF-α和IL-6的变化。结果:①烧伤及LPS注射后大鼠各时相点外周血LPS浓度均明显高于假烫组。②烧伤血清组、LPS组大鼠AM各时相点CD14 mRNA表达均明显增高,TNF-α和IL-6浓度亦相应显著增高(P<0.01)。烧伤血清作用1 h后TNF-α和IL-6浓度即显著增加;血清抗体组AM的CD14mRNA表达显著降低(P<0.01),TNF-α和IL-6浓度亦显著降低(P<0.01)。内毒素抗体组AM在各时相点CD14mRNA表达显著降低(P<0.01),TNF-α和IL-6浓度亦显著降低(P<0.01)。结论:严重烧伤后外周血LPS浓度增加,在体和离体AM CD14 mRNA表达均显著增加,这使LPS对免疫系统的激活作用显著增大,AM分泌TNF-α和IL-6明显增加,抗CD14抗体可以拮抗炎性介质的合成和分泌。提示严重烧伤后通过调节CD14的作用而减少炎性介质的合成和分泌是可行的。
Objective： Inflammatory response syndrome （SIRS） is due to the large number of inflam- matory mediators were synthesized and released. The major goal of this studies was to observe the role of pulmonary alveolar maerophage （AM） CD14 protein on the production of TNF-α and IL-6 in severely burned rats and LPS injection in the early stage. Methods：SD rats were burned with 20%TBSA Ⅲ° injury and the dynamic changes of plasma level of LPS was observed . After AMs were isolated from burned rats and cultured, levels of AMs CD14 mRNA expression were detected with RT-PCR, immuno- histochemistry and ELISA respectively. In vitro, the superuatant of normal rat AMs were cultured with postburn rat serum with or without CD14 antibody, and levels of TNF-α and IL-6 in the culture were al- so detected. Results：Levels of plasma LPS increased significantly after severe burn injury. The ex- pression of CD14 mRNA in the AMs increased correspondingly in vitro and in vivo. The levels of TNF-α and IL-6 in the supernatant of AMs were also increased. When AMs were cultured with postburn serum, the level of TNF-α and IL-6 in the supernatant increased significantly, which could be reversed at the presence of CD14 antibody. Conclusion：After severe burn injury, the stimulating role of LPS to the immune system was enhanced because of the increase of plasma LPS level and numbers of AMs CD14 receptor, resulting in the increase of TNF-α and IL-6 secretion. This indicated that the production of proinflammatory cytokines may be inhibited via modulating CD14 signal transduction.
出处
《医学研究生学报》
CAS
2009年第6期578-581,586,共5页
Journal of Medical Postgraduates
基金
国家自然科学基金资助项目(批准号:39870859)
