多房棘球蚴感染早期肝纤维化的实验动物研究

Initial study on early-stage hepatic fibrosis in mice with Echinococcus multilocular infection

目的建立多房棘球蚴感染小鼠模型,观察感染早期肝脏纤维化的动态变化。方法将40只C57BL/6小鼠分为实验组和对照组,其中实验组为25只,对照组15只。实验组采用小鼠门静脉注入多房棘球蚴原头节混悬液,对照组门静脉注射等量的生理盐水。分别于感染后1、2、3、4、8周采集标本,通过苏木精-伊红(HE)染色动态观察组织的病理学改变及幼虫病灶、炎性病灶和肉芽肿组织的变化情况;采用天狼猩红染色观察小鼠肝组织胶原蛋白的沉积程度;通过免疫组化染色观察不同时间点的α-SMA表达情况。结果实验组小鼠的肝组织随着感染时间的延长其带虫病灶的数量逐周降低,而肉芽肿数量则逐周增多;炎性病灶无明显变化,脾脏和肾脏组织亦未见多房棘球蚴感染征象。天狼星红染色显示,对照组小鼠中的胶原沉积在胆管及血管周围,而实验组小鼠中则主要沉积在病灶及其周围,而且随着感染时间的延长其沉积程度越重。免疫组化结果提示对照组小鼠的α-SMA未见明显表达,而实验组小鼠的肝脏阳性表达多在原头蚴周围的组织增生区域,感染后α-SMA的表达逐周增加。结论经门静脉感染多房棘球蚴的动物模型,可为肝泡型包虫病的相关研究提供良好的模拟环境。多房棘球蚴感染早期肝脏的纤维化可能与α-SMA相关。

Objective To establish a mouse model with Echinococcus multilocular(E.m)infection,and dynamically study on the changes in early-stage liver fibrosis.Methods A total of 40 C57BL/6 mice were divided into experimental group with 25 mice and control group with 15 mice.The E.m Protoscolex suspension was injected through portal vein for the experimental group,while the normal saline solution was injected through its portal vein for the control group.The specimens were taken on 1,2,3,4 and 8 weeks after the infection.The Histopathological changes were observed by Hematoxylin-Eosin staining(H&E),and the fibrosis degree of liver tissue was studied by Sirius-Red staining,and moreover,α-SMA expression was showed by immunohistochemical staining.Results In the experimental group,the number of lesions with worms showed a time-dependent decrease,and meanwhile the amount of granulomas appeared an increase;the inflammatory lesions did not change significantly,and there were no significant signs of the E.m infection in spleen and kidney tissues;Sirius-Red staining demonstrated,collagen deposition in the control group was mainly around the bile duct and blood vessels,however,in the experimental group,the deposition was mainly around the lesion and the degree of fibrosis became more serious time-dependently.There was fewα-SMA expression by immunohistochemical staining in the control group,and mostly granulomatous areas around the metacercariae and fibroblasts in the experimental group,in addition,theα-SMA expression increased over the time after the E.m infection.Conclusion The animal model of E.m infection via portal vein can provide a better simulation environment for the further study of the hepatic alveolar echinococcosis.Hepatic fibrosis may be associated with theα-SMA expression at the early-stage of E.m infection.