中性粒细胞弹性蛋白酶在小鼠实验性结肠炎中的表达及意义

目的：观察中性粒细胞弹性蛋白酶（NE）在葡聚糖硫酸钠（DSS）诱导的小鼠实验性结肠炎中的表达情况并探讨其表达的意义。方法：健康雄性BALB/c小鼠随机分为正常对照组、模型组。模型组小鼠予5%DSS溶液自由饮用制备小鼠急性实验性结肠炎模型,正常对照组小鼠予蒸馏水自由饮用。每日观察小鼠的一般状况及疾病活动指数（DAI）评分,于实验第5、9天分批处死小鼠,取小鼠结肠行组织学损伤评分;ELISA法检测小鼠血浆中性粒细胞弹性蛋白酶浓度;Western blot法检测远端结肠组织中NE蛋白的表达。结果：与正常对照组相比,模型组小鼠在实验第5天及第9天DAI评分显著升高（P〈0.001）、结肠组织学损伤评分明显升高（P〈0.01）、血浆NE浓度明显升高（P〈0.01）、远端结肠NE蛋白表达增加显著（P〈0.001）。在实验第5天及第9天,模型组小鼠DAI评分与组织学损伤评分呈显著正相关（P〈0.05）,血浆中NE浓度及结肠中NE蛋白的表达与DAI评分、组织学评分均呈显著正相关（P〈0.05）。结论：NE在实验性结肠炎小鼠血浆及结肠组织中表达明显增加,且与疾病活动指数及组织学评分呈正相关,提示NE可能参与实验性结肠炎小鼠的发病。

The expression of neutrophil elastase in murine experimental colitis

Objective： To observe the expression of neutrophil elastase （NE） in dextran sulfate sodium （DSS）-induced experimental colitis in mice and explore its expression significance. Methods： Healthy male BALB/c mice were randomly divided into two groups： normal control group and the model group. Acute experimental colitis was induced by providing mice with 5% DSS ad-libitum in model group, and mice in normal control group were provided with sterile distilled water ad-libitum. Observe the general state of health and the disease activity index （DAI） of every mouse daily. Mice were sacrificed on day 5 and day 9, and samples from colon and plasma in all mice were then obtained. Histological disease scores in colon were recorded. Enzyme-linked immunosorbent assay （ELISA） was used to detect the concentration of NE in plasma, and the expression of NE in distal colon was analyzed by Western blotting. Results： Compared to normal control group, the disease activity index in model group was increased strikingly on either day 5 or day 9 （P〈0.001）; the histological disease scores and the NE concentration were markedly advanced in model group （P〈0.01）,and the expression of NE protein in distal colon was also increased dramatically （P〈0.001）. There was a significant positive correlation between DAI and histological disease scores on either day 5 or day 9 （P〈0.05）. The concentration of NE in plasma and the expression of NE in colon tissues were remarkably positive correlation with DAI and histological disease scores （P〈0.05）. Conclusions： The expressions of NE in both plasma and colon tis- sues,which were positive correlation with DAI and histological disease scores, increased evidently in murine experimental colitis, there- fore revealed NE may involve in the pathogenesis of UC.