ABSTRACT
Objective To investigate the anti-fibrogenesis property and mechanism of short hairpin RNA (shRNA ) targeting heat shock protein 47 (HSP47) in schistosomiasis liver fibrosis mice model . Methods Sixty female BALB/c mice (SPF level) were infected percutaneously with (16 ± 1) Schistosoma japonicum cercariae . Twelve mice which were not infected with Schistosoma japonicum were set as uninfected control .The 60 mice were randomly divided into five groups including 1 mg/kg HSP47-shRNA intervention group ,2 mg/kg HSP47-shRNA intervention group ,4 mg/kg HSP47-shRNA intervention group ,unrelated shRNA intervention group and infected control group ,with 12 mice each group .From 6 to 14 weeks post infection ,mice in HSP47-shRNA intervention groups were intravenously injected with HSP47-shRNA weekly and those in unrelated shRNA intervention group were intravenously injected with 2 mg/kg of unrelated shRNA vector weekly .Survival rate ,liver and spleen in general and liver histology of mice in each group were observed at week 14 which was considered as end of intervention . The expressions of HSP47 mRNA and protein were determined by real-time polymerase chain reaction (PCR) and Western blot .Collagen type Ⅰ ,collagen type Ⅲ ,tissue inhibitor of metalloproteinase-1 (TIMP-1) , matrix metalloproteinase-9 (MMP-9) ,plasminogen activator inhibitor-1 (PAI-1) ,transforming growth factor-β1 (TGF-β1 ) , connective tissue growth factor (CTGF ) , interleukin (IL )-13 and IL-17 at transcriptional level were measured by real-time PCR .Means among groups were compared using student-t test .Results In vivo intervention of HSP47-shRNA mainly localized in hepatic stellate cells of mice . The survival rate of 1 mg/kg ,2 mg/kg and 4 mg/kg HSP47-shRNA intervention groups were 25 .00% , 25 .00% and 33 .33% , respectively .Mice received 4 mg/kg dose of HSP47-shRNA had significantly higher survival rate than the infected controls (χ2 = 4 .168 ,P= 0 .043) .In both 4 mg/kg HSP47-shRNA intervention group and the infected control group , hematoxylin and eosin staining showed chronic granuloma change ,of which ova were wrapped by the spindle-shaped collagen and inflammatory cell infiltrated .The percentage of positive staining for Masson trichrome and sirius red showed the quantity of the collagen deposition was significantly reduced by the HSP 47-shRNA intervention ,compared to the infected control group (t = 3 .191 ,P = 0 .039) .HSP47-shRNA significantly reduced HSP47 expression , and reduced the transcriptional levels of collagen type Ⅰ ,collagen type Ⅲ ,TIMP-1 ,PAI-1 ,TGF-β1 , CTGF ,IL-13 and IL-17 (all P < 0 .01) ,and increased the expression of MMP-9 mRNA ( P < 0 .01) . Conclusion Delivery of shRNA targeting HSP47 to the hepatic schistosomiasis mice model can silence the expression of HSP47 and improve the liver fibrosis .Collagen degradation and related cytokines release through upregulation of MMP-9 and downregulation of PAI-1 may be one of the anti-fibrotic mechanisms in HSP47-shRNA intervention .