Smad蛋白在小鼠感染日本血吸虫形成肝纤维化过程中的表达  

Expression of Smad Proteins in the Process of Liver Fibrosis in Mice Infected with Schistosoma japonicum

作　　者：张彬彬[1] 蔡卫民[2] 陶君[3] 郑敏[2] 刘荣华[2] 

机构地区：[1]黑龙江省医院消化病院消化一科,哈尔滨150001 [2]浙江大学医学院附属第一医院传染病研究所,杭州310003 [3]解放军杭州疗养院,杭州310003

出　　处：《中国寄生虫学与寄生虫病杂志》2013年第2期89-94,共6页Chinese Journal of Parasitology and Parasitic Diseases

基　　金：国家"十五"科技攻关计划项目(No.2001BA705B08)~~

摘　　要：目的研究参与转化生长因子-β1(transforming growth factor-beta1,TGF-β1)信号传导的Smad蛋白在日本血吸虫病小鼠肝纤维化形成过程中的表达。方法34只6-8周龄的健康BALB/c小鼠(SPF级),每鼠经腹部皮肤感染日本血吸虫尾蚴(20±1)条,分别于感染8、12、16和24周后,麻醉处死小鼠8、8、8和10只,取肝组织,用10%甲醛固定。10只未感染日本血吸虫尾蚴的健康小鼠为对照组,分别于上述时间取肝组织。肝组织切片后,经苏木素-伊红(HE)染色,低倍镜下(×100)用测微量器测定单个虫卵肉芽肿面积。天狼猩红染色观察感染小鼠的肝纤维化程度。免疫组织化学法检测Smad2/3、Smad4和Smad7蛋白的表达情况。结果小鼠肝组织中虫卵肉芽肿面积在感染8周后达到峰值,为(5.33±1.03)mm2;随着感染时间的延长,虫卵肉芽肿面积缩小;至感染24周后仅为(2.94±1.69)mm2,不同感染时间组间差异有统计学意义(P<0.05)。天狼猩红染色结果可见,小鼠感染8周后,虫卵肉芽肿周围出现胶原纤维沉积,沉积量为(2.03±0.52);随着感染时间的延长,胶原纤维沉积量增加,并向肝小叶内延伸;感染24周后,胶原纤维沉积量达到峰值(6.90±1.57),不同感染组间差异有统计学意义(P<0.05)。免疫组织化学检测结果显示,健康小鼠肝组织的肝窦区可见Smad2/3和Smad7呈低水平表达,而Smad4表达不明显。小鼠感染8周后,Smad2/3主要表达在虫卵肉芽肿周围细胞的胞浆和胞核内,其阳性面积为(7.24±1.64)%;感染12周后,Smad2/3在虫卵肉芽肿周围和肝窦区表达增强[(10.01±1.07)%],各感染组与对照组[(2.13±0.32)%]差异均有统计学意义(P<0.05),感染12周组与感染8周组和感染16周组之间的差异亦有统计学意义(P<0.05)。小鼠感染8周后,Smad4表达水平[(8.81±1.13)%]高于对照组[(4.83±1.15)%](P<0.05),但随感染时间延长,其表达量与其他3个感染组差异无统计学意义(P>0.05)。小鼠感染8周后,Smad7主要表达在�Objective To study the expression of Smads proteins involved in TGF-β1 signal transduction during the process of liver fibrosis in BALB/c mice infected with Schistosoma japoncum. Methods Thirty-four BALB/c mice were each infected with （20±1） S. japonicum cercariae. The mice were sacrificed at 8, 12, 16 and 24 weeks post-infection. Ten healthy BALB/c mice served as normal control group. The liver tissues were fixed in 10% formaldehyde for histology and immunohistochemistry assay. The single-egg granuloma area was measured in hematoxylin-eosin stain section. The degree of liver fibrosis was determined by Sirius red staining. Immunohistochemistry was used to observe the expression of Smad protein. Results The area of single-egg granuloma peaked at 8th week post-infection [（5.33±1.03） mm2], and with time passing, the area diminished, and the area of granuloma reduced to（2.94±1.69）mm2 at 24 weeks post-infection. The difference was significant among the 4 periods after infection in single-egg granuloma area（P〈0.05）. Collagen fibers appeared around granulomas at 8 weeks （2.03±0.52） and increased gradually. At 24 weeks post-infection, the degree of liver fibrosis reached a peak（6.90±1.57）, and the liver fibrosis degree was significantly different among infection groups（P〈0.05）. Immunohistochemistry showed low expression level of Smad2/3 and Smad7 and inconspicuous level of Smad4 in livers of the normal mice. The expression of Smad2/3 was found mostly in the cytoplasm and nucleus of cells around granulomas at 8th week post-infection, and the positive area of Smad2/3 was （7.24±1.64）% by semi-quantity. At 12 weeks post-infection, the Smad2/3 protein expression level around granulomas and liver sinus reached the peak[（10.01±1.07） %], and there was significant difference between infection groups and the control [（2.13±0.32）%]. A significant difference in the Smad2/3 protein expression level was found between 12 weeks post-infection group and 8 weeks or 16 weeks post-in

关 键 词：日本血吸虫病 虫卵肉芽肿 肝纤维化 SMAD蛋白 

分 类 号：R532.21[医药卫生—内科学]