内毒素休克小鼠脂钙蛋白2及相关细胞因子的表达

Expressions of Lipocalin 2 and Its Relative Cytokines in Endotoxic Mice

目的探讨内毒素对小鼠脂钙蛋白2(lipocalin 2,LCN2)及其相关细胞因子表达水平的影响。方法 C57BL/6小鼠随机分为4组(n=8),实验组分别予10、20、30mg/kg内毒素腹腔内注射,对照组仅注射等容积生理盐水。观察24h后留取盲肠和血清,酶联免疫吸附法和蛋白免疫印迹法测定白细胞介素(interleukin,IL)-1β、IL-6、IL-17A、LCN2水平,实时PCR相对定量肠组织中LCN2 mRNA。结果与对照组比较,大剂量内毒素组(20mg/kg和30mg/kg)的血清IL-6、LCN2与肠组织IL-1β、IL-6、IL-17A、LCN2水平均显著增高(P<0.05)。与10mg/kg组比较,30mg/kg组的血清IL-6、LCN2以及肠组织IL-1β、IL-17A、LCN2水平均显著增高(P<0.05)。对照组及10、20、30mg/kg内毒素组肠组织LCN2mRNA相对定量值分别为1.548±0.417、3.184±0.716、4.875±0.547、7.489±0.820,两两比较差异均有统计学意义(P<0.05)。结论内毒素可剂量依赖性地引起小鼠肠组织LCN2表达水平增高;血清IL-6与LCN2水平以及肠组织IL-1β、IL-17A与LCN2水平之间存在一定的相关性。

Objective To explore the influence of an endotoxin lipopolysaccharide （ LPS） injection on theexpressions of lipocalin 2 （LCN2） and its relative cytokines in mice. Methods C57BL/6 mice were randomlydivided into 3 groups （ n = 8 each） according to the serial LPS dosages of 10,20,and 30 mg/kg. The controlgroup （n =8 ） received only isotonic saline injection. Twenty-four hours later, cecum and blood samples werecollected, and enzyme-linked immunosorbent assay （ELISA） and Western blot were performed to detect the serum levels of interleukin （IL）-1β, IL-6, IL-17A, and LCN2,and real-time polymerase chain reaction （ PCR）to determine the LCN2 mRNA level in cecum lysate. Results The serum levels of IL-6 and LCN2 and the levelsof IL-1β, IL-6, IL-17A,and LCN2 in cecum lysate in two large-dosage LPS groups （20 mg/kg and 30 mg/kg）were significantly higher than their counterparts in control group （ P 〈 0. 05 ） . Compared with the 10 mg/kg LPSgroup,the levels of IL-6 and LCN2 in serum and the levels of IL-1β,IL-17A,and LCN2 in cecum lysate signifi-cantly increased in the 30 mg/kg LPS group （ P 〈 0. 05 ）. 2 ^-△△CT was used to indicate fold changes of LCN2mRNA in intestine. The results expressed as mean ± standard deviation were as follows： 1. 548 ±0. 417 for control group, 3. 184 ±0. 716 for 10 mg/kg LPS group, 4. 875 ±0. 547 for 20 mg/kg LPS group, and 7. 489 ±0. 820for 30 mg/kg LPS group, and the difference was significant between either two groups （P 〈0. 05）. ConclusionsLPS dose-dependently increases the level of LCN2 expression in cecum. The serum IL-6 level as well as thececum IL-1β and IL-17A levels have certain correlations with the LCN2 level.