重组人N末端脂多糖结合蛋白对脂多糖致伤小鼠保护作用的初步研究

Study on the protective effect of recombinant human N-terminal lipopolysaccharide binding protein in mice challenged with LPS

目的 初步观察重组人N末端脂多糖结合蛋白 (tLBP)对细菌脂多糖 (LPS)致伤小鼠的保护效应。 方法 选用雄性昆明小鼠 70只 ,随机分为致伤组 1(2 1只 ) :腹腔内注射LPS 10 0ng;保护组 1(2 1只 ) :腹腔内注射 10 0ngLPS +40mgtLBP;对照组 (8只 ) :腹腔内注射等渗盐水。于注射后15、30min及 1、3、6、12、2 4h测定 3组动物血清丙氨酸转氨酶 (ALT)及肿瘤坏死因子α(TNF α)的含量 ,并观察其肝、肺组织的病理学改变。另设致伤组 2及保护组 2各 10只 ,分别腹腔内注射LPS 4 0 0ng及4 0 0ngLPS +40mgtLBP,观察伤后 2 4h内动物的死亡数。 结果 保护组 1与致伤组 1血清ALT含量分别于伤后 12、6h到达峰值 ,各为 (41.0 0± 4 .5 8)、(99.5 0± 6 2 .6 3)U L,前者的升高幅度显著低于后者 (P <0.0 1);两组血清TNF α含量均于伤后 3h到达峰值 ,各为 (35 .96± 7.33)、(42 .4 9± 4 .79)fmol ml,保护组 1的升高幅度低于致伤组 1。与致伤组 1比较 ,保护组 1肝细胞变性程度明显减轻 ,未见肝细胞散在坏死病变 ;肺组织充血有不同程度减轻 ,肺泡腔内、支气管内炎性渗出明显减弱。致伤组2伤后 2 4h死亡 9只 ,保护组 2死亡 3只。 结论 初步认为重组人tLBP具有一定的生物学活性 ,对LPS致伤小鼠具有一定保护作用。

Objective To investigate the protective effect of recombinant human N-terminal lipopolysaccharide binding protein in mice challenged with LPS. Methods Seventy male Kunming mice were randomly divided into 3 groups, i. e. LPS challenge (Injection of LPS into abdominal cavity, n=21);tLBP protection (Injection of LPS and tLBP into abdominal cavity, n=21) and control (Injection of normal saline into abdominal cavity, n=8) groups. The blood samples and tissue samples of the liver and lungs were harvested on 15 and 30 minutes and 1, 3, 6, 12 and 24 hours after the injection. The serum contents of ALT and TNF-α were determined by biochemical velocity analysis and RIA method, respectively. The pathomorphological changes in the liver and pulmonary tissue were examined under light microscope(LM). The mortality rate of ten mice each was observed within 24 hours after the injection of tLBP+400ng LPS or 400ng LPS. Results The ALT content of tLBP group reached the peak level at 12 post-injection hour(PIH)(41.00±4.58),but it was significantly lower than that in LPS group in which it peaked at 6PIH(99.50±62.63)(P<0.01). The TNF-α content in tLBP and LPS group was lower than that in LPS group, and both reached the peak level at 3 PIH(35.96±7.33). Compared with those in LPS, injury to hepatocytes in tLBP group was obviously milder without scattered necrosis. The pulmonary congestion in tLBP group was abated, and the inflammatory exudation in the alveoli was evidently less than that in LPS group. There were 9 out of 10 mice died in the LPS challenge group, while only 3 out of 10 mice died during 24 hours after LPS injection in tLBP protection group. Conclusion Preliminary results indicated that recombinant human tLBP might possess biological activity with a potential protection effect in LPS challenged mice.