脂多糖对不同发育期小鼠肝脏β-防御素3表达的影响

Effect of LPS on regulation of mouse liver β-defensin-3 expression in different development stages

目的:观察在脂多糖(Lipopolysaccharide,LPS)诱导条件下,胎鼠(E14.5,E17.5),新生鼠(P0,P4)以及成年鼠肝脏中鼠β-防御素3(mouseβ-defensin 3,mBD-3)基因表达。方法:100只孕鼠随机平均分成2组:LPS感染组(E14.5、E17.5、P0、P4、a-dult),正常对照组(E14.5、E17.5、P0、P4、adult)(n=50)。LPS感染各组分别于E13.5,E16.5,E17.5(Embroynic day)天,孕鼠腹腔注射550μg.kg-1LPS(100μl),同时正常对照组也注射等量生理盐水,24 h后取出肝脏。提取RNA及蛋白,采用RT-PCR及Western blotting检测mBD-3的RNA及蛋白表达;同时取出左半肝经4%多聚甲醛固定后,石蜡包埋切片,免疫组化法检测mBD-3的阳性表达,图像分析系统进行定量分析,并进行统计学处理。结果:正常对照组小鼠肝脏在胎鼠以及新生鼠期均未检测到mBD-3的表达,而LPS感染组小鼠肝脏在胎鼠以及新生鼠时期均检测到大量mBD-3的阳性表达,且随着时间的增加呈上升的趋势(P<0.05)。结论:mBD-3在正常的胎肝以及新生小鼠肝脏中未检测到表达,在LPS的诱导下,其在不同发育期小鼠肝脏组织中表达均明显增高。这提示不同发育阶段小鼠肝组织在受到外界感染侵袭后,mBD-3可能是肝组织抵抗微生物感染的重要抗菌分子。

Objective：To observe the expression of β-defensin 3（mouse β-defensin 3,mBD-3） at the different stages of the liver development of mice in normal and upon LPS infection.Methods： 100 pregnant mice were randomly divided into LPS group（n=50） and normal control group（n=50）,the pregnant mice in LPS group（E14.5,E17.5,P0,P4,adult）were intrapertinally injected into 550 μg·kg-1 LPS at E13.5,E16.5,E17.5 and at the same time mice in the normal control group（E14.5,E17.5,P0,P4,adult）were injected with normal saline.After 24h,the livers were extracted to obtain RNA and protein,and then RT-PCR and Western blotting were used to detect the expression of mBD-3.And the left liver tissues were employed immunohistopathologic method to measure the positive expression of mBD-3.Results： The expression of mBD-3 had too weak to determine in fetus and neonatal mice.Subsequently,its expression was increased significantly after LPS administration.And following the development,the inducible expression enhanced（P0.05）.Conclusion：mBD-3 expression were not detected in normal mouse liver of different developmental stages,but the expression were increased by LPS infection,which suggested that mBD-3 might play an important role in defense of liver development.