苏拉明对脓毒症小鼠肺组织和循环炎症反应的抑制作用

Inhibitory effect of suramin on inflammatory response in pulmonary tissue and peripheral blood in LPS-induced septic mice

目的：观察苏拉明对脓毒症小鼠肺组织和循环炎症反应的抑制作用，并初步探讨其相关分子生物学机制。方法：①体内实验：将24只雄性C57BL／6小鼠按数字表法分为苏拉明组和生理盐水组，苏拉明组给予静脉注射5mg／kg苏拉明预处理。生理盐水对照组给予等体积0．9％氯化钠溶液，30min后采用静脉注射5mg／kg脂多糖（LPS）建立脓毒症小鼠模型，检测不同时间点肺组织和外周血TNF．仅和IL-15水平。②体外实验：苏拉明或生理盐水预处理人单核细胞系THP-1细胞30min后，用100ng／mL LPS刺激建立脓毒症细胞模型，于不同时间点收集THP-1细胞，提取RNA，定量PCR检测TNF—α和IL-6表达水平，并分离细胞浆和细胞核蛋白，蛋白质印迹法检测核因子KB（NF-kB）活性。结果：LPS干预后小鼠肺和外周血TNF—α和IL-6水平增加，提示成功建立脓毒症小鼠模型。与生理盐水组比较，苏拉明干预脓毒症小鼠模型作用24h时小鼠肺组织及外周血TNF—α和IL-6的水平降低（均P〈0．01）；而苏拉明作用72h时各组小鼠肺组织及外周血TNF-α和IL-15的水平差异无统计学意义（均P〉0．05）。体外实验结果显示：苏拉明预处理减少LPS刺激THP-1细胞后TNF-α和IL-6的表达水平（均P〈0．01），苏拉明预处理还减少LPS刺激30min、60min和90min后THP-1细胞NF-kB的活化水平（均P〈0．01）。结论：苏拉明可减轻小鼠全身及肺组织炎症反应，在对脓毒症肺损伤模型中具有保护作用，其炎症反应的调控可能与抑制脓毒症单核细胞的过度活化有关。

Objective： To investigate the effect of suramin on inflammatory response in pulmonary tissue and peripheral blood in septic mice. Methods： Twenty-four male C57BL/6 mice were randomly divided into two groups, and suramin （5 mg/kg） or normal saline was intravenously injected 30 min before LPS （5 mg/kg ） infusion＇ respectively. The contents of TNF-α and IL-6 in pulmonary tissue and peripheral blood were detected by ELISA. Suramin or saline-pretreated human mononuclear THP-1 cells were treated with 100 ng/mL LPS in vitro. The expression of TNF-α and 1L-6 mRNA and the activity of NF-kB were analyzed by quantitative PCR and Western blotting at different time points after LPS treatment, respectively. Results： Compared with the saline group, the TNF-α and IL-6 levels in pulmonary tissue and peripheral blood were significantly reduced in suramin group at 24 h after LPS treatment （ all P 〈 0.01 ） ; while there was no significant difference at 72 h between two groups （ all P 〉 0.05 ）. The expression of TNF-α, IL-6 mRNA and the activity of NF-kB was decreased in suramin group at different time points after LPS treatment. Conclusion： Suramin can protect LPS-induced acute lung injury through down-regulation of systemic and pulmonary pro-inflammatory factors, which may be associated with the inhibition of NF-kB activity.