泡球蚴感染小鼠肝脏α-SMA和Ⅰ型胶原的表达及其意义

α-SMA and typeⅠcollagen expression in the livers of mice infected with Echinococcus multilocularis

目的探讨α-SMA和Ⅰ型胶原在不同剂量泡球蚴感染C57BL/6小鼠肝脏中的表达及其意义。方法采用门静脉注射法建立泡球蚴感染C57BL/6小鼠模型,分别设假手术(生理盐水)组、低剂量泡球蚴感染组(250个原头蚴)和高剂量泡球蚴感染组(1000个原头蚴),16周后采集小鼠肝脏标本,HE和天狼猩红染色鉴定肝脏纤维化程度,免疫组化法检测ɑ-SMA和Ⅰ型胶原的表达。结果HE染色显示高剂量泡球蚴感染组小鼠肝脏以成囊病灶为主要病理表现,低剂量泡球蚴感染组小鼠肝脏以修复病灶为主;天狼猩红染色显示高剂量泡球蚴感染组小鼠肝脏纤维化阳性面积比值为(32.63±9.24)%,低剂量泡球蚴感染组为(3.48±0.67)%,和假手术组为(0.50±0.17)%,差异有统计学意义(P<0.05)。免疫组化显示α-SMA在高剂量泡球蚴感染组小鼠肝脏中阳性表达面积比值为(10.68±1.18)%,低剂量泡球蚴感染组(2.38±0.35)%,假手术组为(0.36±0.09)%,差异有统计学意义(P<0.01);Ⅰ型胶原在高剂量泡球蚴感染组小鼠肝脏中阳性表达面积比值为(7.93±0.78)%,低剂量泡球蚴感染组为(2.38±0.35)%,假手术组为(0.26±0.08)%,差异有统计学意义(P<0.01)。结论Ⅰ型胶原的表达与泡球蚴感染剂量的增加和小鼠肝脏纤维化程度的加重呈正相关。

Objective To investigate the expression and significance ofα-SMA and typeⅠcollagen in the livers of C57BL/6 mice infected with Echinococcus multilocularis protoscoleces(PSCs).Methods Mice were inoculated with different doses of PSCs via the hepatic portal vein and were divided into three groups,a sham-surgery group(0.9%Nacl),a low-dose group(250 PSCs),and high-dose group(1000 PSCs).Livers of mice were collected 16 weeks after infection.The degree of liver fibrosis was identified using HE and Sirius red staining,and the expression ofα-SMA and typeⅠcollagen was determined immunohistochemically.Results HE staining revealed cystic lesions(the main pathological manifestations of infection)in the livers of mice in the high-dose group,while lesions in the livers of mice in the low-dose group healed.Sirius red staining indicated that the proportion of the area positive for liver fibrosis was 32.63±9.24%in the high-dose group,3.48±0.67%in the low-dose group,and 0.50±0.17%in the sham-surgery group.The proportion of the area positive for liver fibrosis differed significantly(P<0.05).Immunohistochemistry indicated that the proportion of the area positive forα-SMA expression was 10.68±1.18%in the livers of mice in the high-dose group,2.38±0.35%in the low-dose group,and 0.36±0.09%in the sham-surgery group.The proportion of the area positive forα-SMA expression differed significantly(P<0.01).The proportion of the area positive for typeⅠcollagen expression was 7.93±0.78%in the livers of mice in the high-dose group,2.38±0.35%in the low-dose group,and 0.26±0.08%in the sham-surgery group.The proportion of the area positive for type I collagen expression differed significantly(P<0.01).Conclusion The expression of typeⅠcollagen is positively correlated with the dose of PSCs and the increased severity of liver fibrosis in mice infected with E.multilocularis.