芦荟大黄素和吡喹酮联合治疗对血吸虫肝纤维化小鼠TGF-β/Smad通路的影响

Effects of combined use of aloeemodin and praziquantel on the transforming growth factor-β/Smad pathway in mice with schistosomiasis-induced liver fibrosis

目的:探讨芦荟大黄素和吡喹酮的联合治疗对血吸虫肝纤维化小鼠TGF-β/Smad通路的影响.方法:80只小鼠随机分为4组.前3组每只小鼠感染日本血吸虫尾蚴25条.感染8wk后,第一组小鼠以吡喹酮500mg/(kg·d)治疗2d(吡喹酮组),第2组小鼠以吡喹酮500mg/(kg·d)治疗2d后用芦荟大黄素0.3mg/(kg·d)治疗8wk(吡喹酮+芦荟大黄素组),第3组不作任何治疗(实验对照组),第4组小鼠作为正常对照.第16周末处死小鼠留取肝脏组织,应用HE染色法、RT-PCR法和免疫组织化学染色法观察、分析各组小鼠肝脏病理改变与Smad2mRNA、Smad7mRNA、TGF-β1、TIMP-1、Ⅰ型胶原及Ⅲ型胶原的表达变化.结果:芦荟大黄素治疗后血吸虫肝纤维化程度减轻,肝组织中Smad2mRNA、TGF-β1、TIMP-1、Ⅰ型胶原、Ⅲ型胶原的表达明显低于实验对照组和吡喹酮组(q=6.20,4.38;q=6.22,4.41;q=6.30,4.52;q=6.25,4.44;q=6.29,4.48,P<0.01或0.05);肝组织中Smad7mRNA的表达,明显高于实验对照组和吡喹酮组(q=6.32,4.62,P<0.01或0.05).结论:芦荟大黄素可通过降低肝组织中TGF-β1、TIMP-1、Ⅰ型胶原、Ⅲ型胶原的表达,抑制Smad2基因的表达,促进Smad7的表达发挥抗肝纤维化作用.

AIM：To investigate the effects of combined use of aloeemodin and praziquantel on the transforming growth factor-β （TGF-β）/Smad pathway in mice with schistosomiasis-induced liver fibrosis. METHODS：Eighty mice were randomly divided into four groups：normal control group,infec-tion group,praziquantel treatment group,and praziquantel and aloeemodin treatment group. Mice in the infection group and the two treatment groups were infected with 25 Schistosoma japonicum cercariae. Eight weeks after infection,mice in the praziquantel treatment group were treated with praziquantel at a dose of 500 mg/（kg·d） for two days,while those in the praziquantel and aloeemodin treatment group were treated with praziquantel at the same dose for the same duration followed by treatment with aloeemodin at a dose of 0.3 mg/（kg·d） for 8 weeks. At week 16,all mice were sacrif iced to take liver tissue samples. Hematoxylin and eosin staining was performed to observe changes in hepatic histopathology. Reverse transcription-polymerase chain reaction （RT-PCR） was used to detect the expression of Smad2 and Smad7 mRNAs in the liver. Immunohistochemical staining was performed to detect the expression of TGF-β1,TIMP-1,and type Ⅰ and Ⅲ collagen in liver tissue. RESULTS：Aloeemodin treatment relieved the degree of hepatic fibrosis. The expression levels of Smad2 mRNA and TGF-β1,tissue inhibitor of metalloproteinases-1 （TIMP1）,and type Ⅰ and Ⅲ collagen proteins in liver tissue were significantly lower in the praziquantel and aloeemodin treatment group than in the infection group and the praziquantel treatment group （q = 6.20 and 4.38,6.22 and 4.41,6.30 and 4.52,6.25 and 4.44. and 6.29 and 4.48,respectively; all P〈0.01 or 0.05）. In contrast,the expression level of Smad7 mRNA was significantly higher in the praziquantel and aloeemodin treatment group than in the infection group and the praziquantel treatment group （q = 6.32 and 4.62,respectively; P〈0.01 and 0.05,respectively）. CONCLUSION：Aloeemodin exerts anti-fibrotic effects perhaps through downregulation of the expression of Smad2 mRNA and TGF-β1,TIMP1,and type Ⅰ and Ⅲ collagen proteins,and upregulation of the expression of Smad7 mRNA.