诱导型一氧化氮合酶在感染日本血吸虫小鼠肝组织中的表达

Expression of Inducible Nitric Oxide Synthase in the Livers of Mice Infected with Schistosoma japonicum

目的 研究诱导型一氧化氮合酶 (iNOS)在感染日本血吸虫小鼠肝脏中的动态表达。 方法 日本血吸虫尾蚴经皮肤感染NMRI小鼠 ,感染后第 0、2 1、2 8、3 8和 45天取其肝组织 ,用逆转录聚合酶链反应 (RT PCR)半定量法检测i NOS转录水平的动态表达 ,用蛋白质印迹法 (Westernblotting)测定表达的蛋白变化 ,并用免疫组化方法确定iNOS在肝组织中的表达定位。 结果 RT PCR结果显示 ,未感染小鼠肝组织中未见iNOS的表达 ,感染后第 2 1天可见到iNOS在肝组织中的转录表达 ,第 2 8天明显表达 ,第 3 8天达峰值 ,第 45天下降 ,与第 3 8天相比 ,差异无显著性意义 (P >0 .0 5 )。Westernblotting结果表明 ,感染后第 3 8天和第 45天分别可见到iNOS的表达。间接荧光抗体试验结果表明 ,iNOS主要在肝虫卵肉芽肿细胞中表达。 结论 日本血吸虫能诱导宿主肝组织iNOS的动态表达 ,肝组织中的虫卵可能与iNOS表达有关。

Objective To study the expression of inducible nitric oxide synthase (iNOS) in livers of mice infected with Schistosoma japonicum. Methods The livers of NMRI mice infected with S. japonicum were collected on day 21, 28, 38, 45 post infection(p.i.), total RNA of livers were extracted and kinetics of the mRNA expression of iNOS were detected by RT-PCR, the protein expression of iNOS was then confirmed by Western blotting and the distribution of iNOS in the infected liver was determined by immunohistochemical methods. Results The mRNA expression of iNOS was not detectable in the uninfected liver, iNOS mRNA expression was detected on day 21 p.i, the expression increased on day 28 p.i and peaked on day 38 p.i, then decreased slightly on day 45 p.i. Western blotting showed an iNOS expression in the livers only on day 38, 45 p.i. IFA test showed that the expression of iNOS was maily distributed in the granuloma of the livers. Conclusion S. japonicum infection can induce the expression of iNOS in a time-dependent manner in the liver of the host,and eggs may be the main factor in inducing the expression.