沙利度胺对百草枯诱导小鼠急性肺损伤的干预

Effect of thalidomide in a mouse model of paraquat-induced acute lung injury and the underlying mechanisms

目的探讨沙利度胺对百草枯诱导的小鼠急性肺损伤的干预作用及机制。方法将雄性ICR小鼠随机分阴性对照组（30只）、沙利度胺药物对照组（30只）、百草枯中毒组（30只）和50、100、150mg／kg剂量的沙利度胺干预组（各30只），阴性对照组：腹腔注射与染毒剂量相同体积的生理盐水；沙利度胺对照组：腹腔注射沙利度胺150mg／kg；百草枯中毒组：腹腔注射百草枯溶液稀释液（22mg／kg）；沙利度胺干预组：腹腔注射等剂量百草枯溶液（22mg／kg）染毒1h后，再分别注射50、100、150mg／kg的沙利度胺。分别于不同处理1、3、7d后麻醉活杀小鼠，取肺组织。双抗夹心酶联免疫吸附法（ELISA）测定小鼠肺组织肿瘤坏死因子-α（TNF—α）、白细胞介素（IL）-1β、IL-6等炎症因子水平；反转录聚合酶链式反应（PCR）测定NF-κBmRNA的表达；蛋白免疫印迹法（Western—blot）检测胞核内NF-κBP65的蛋白含量。光学显微镜下观察各实验组肺组织病理的表现；比较肺湿干重比。结果与阴性对照组较，百草枯中毒组肺组织TNF-α、IL-1β、IL-6水平和NFK-BmRNA、核内NF．KB蛋白量明显升高，肺湿干比也明显升高，差异均有统计学意义（P〈0．05）。与百草枯中毒组比较，沙利度胺干预组肺组织TNF-α、IL-1β、IL-6水平和NF．KBmRNA、核内NF—κB蛋白量明显降低，肺湿干比明显降低，差异均有统计学意义（P〈0．05）。150mg／kg组沙利度胺干预组肺组织TNF—α、IL-1β、IL-6水平和NF—κBmRNA、核内NF—κB蛋白量降低最明显。病理学观察可见，百草枯中毒组在染毒后3d肺组织损害明显，沙利度胺干预组肺损害较百草枯中毒组有所减轻。结论沙利度胺能减轻百草枯诱导的急性肺损伤和肺水肿，抑制NF-κB的激活及表达，下调TNF-α、IL-1β、IL-6等炎症因子水平可能是其作用机制之一。

Objective To investigate the intervention effect of thalidomide on paraquat-induced acute lung injury in mice and its mechanism. Methods Male ICR mice were randomly allocated to negative control group （n=30）, thalidomide control group （n=30）, paraquat poisoning group （n=30）, 50 mg/kg thalidomide treatment group （n=30）, 100 mg/kg thalidomide treatment group （n=30）, and 150 mg/kg thalidomide treatment group （n=30）. The negative control group was intraperitoneally injected with the same volume of saline; the thalidomide control group was intraperitoneally injected with thalidomide （150 mg/kg）; the paraquat poisoning group was intraperitoneally injected with diluted paraquat solution （22 mg/kg）; each thalidomide treatment group was intraperitoneally injected with the same volume of paraquat solution （22 mg/kg） and was injected with thalidomide （50, 100, or 150 mg/kg） 1 h later. All mice were anesthetized and sacrificed at 1, 3, or 7 d after paraquat poisoning, and their lung tissue was collected. The levels of tumor necrosis factor （TNF）-α, interleukin （IL）-1β, and IL-6 in lung tissue were measured by double-antibody sandwich ELISA; the mRNA expression of nuclear factor-kappa B （NF-KB） was measured by RT-PCR; the protein expression of nuclear NF-KB p65 was measured by Western blot. The pathological changes of lung tissue were observed under light microscope; the wet/dry ratio of the lung was calculated. Results Compared with the negative control group, the paraquat poi- soning group had significantly increased levels of TNF-α, IL-1β, IL-6, NF-KB mRNA, and nuclear NF-KB p65 and wet/dry ratio of the lung （P〈0.05）. Compared with the paraquat poisoning group, the thalidomide treatment groups had significantly decreased levels of TNF-α, IL-1β, IL-6, NF-KB mRNA, and nuclear NF-KB p65 and wet/dry ratios of the lung （P〈0.05）, and the 150 mg/kg thalidomide treatment group showed the most significant decrease in the levels of TNF-α, IL-1β, IL-6, NF-KB mRNA, and nuclear NF-KB p65. The observation of patho- logical changes showed that the paraquat poisoning group had the most marked lung tissue damage at 3 d after poisoning, and the lung tissue damage was lessened in the thalidomide treatment groups. Conclusion Thalidomide can reduce paraquat-induced acute lung injury and lung edema. The mechanism may include inhi- bition of NF-KB activation and expression and downregulation of TNF-α, IL-1β, and IL-6.