AIM:To investigate osteopontin expression and its association with hepatopathologic changes in BALB/C mice infected with Schistosoma japonicum.METHODS:The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria.Liver samples were obtained from mice sacrif iced at 6,8,10,14,and 18 wk after in-fection.Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining.The expression of osteopontin was determined with im-munohistochemistry,reverse transcription-polymerase chain reaction,and Western blotting.The expressionof α-smooth muscle actin(α-SMA)and transforming growth factor-β1(TGF-β1)were determined by im-munohistochemistry.Correlations of osteopontin ex-pression with other variables(α-SMA,TGF-β1,hepato-pathologic features including granuloma formation and degree of liver f ibrosis)were analyzed.RESULTS:Typical schistosomal hepatopathologic changes were induced in the animals.Dynamic changes in the expression of osteopontin were observed at week 6.The expression increased,peaked at week 10(P<0.01),and then gradually decreased.Positive correla-tions between osteopontin expression and α-SMA(r=0.720,P<0.01),TGF-β1(r=0.905,P <0.01),granu-loma formation(r=0.875,P<0.01),and degree of liver f ibrosis(r=0.858,P<0.01)were also observed.CONCLUSION:Osteopontin may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fi brosis through an un-explored mechanism. AIM: To investigate osteopontin expression and its association with hepatopathologic changes in BALB / C mice infected with Schistosoma japonicum. METHODS: The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria. Liver samples were obtained from mice sacrificed at 6, 8 , 10, 14, and 18 wk after in-fection. Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining. The expression of osteopontin was determined with im-munohistochemistry, reverse transcription-polymerase chain reaction, and Western blotting. Expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were determined by im-munohistochemistry. Corlations of osteopontin ex-pression with other variables (α-SMA, TGF- features including granuloma formation and degree of liver f ibrosis) were analyzed.RESULTS: Typical schistosomal hepatopathologic changes were induced in the animals.Dynamic changes i n expression of osteopontin were observed at week 6. The expression increased, peaked at week 10 (P <0.01), and then gradually decreased. Positive correlations between osteopontin expression and α-SMA (r = 0.720, P <0.01) (R = 0.858, P <0.01) were also observed.CONCLUSION: Osteopontin (r = 0.905, P <0.01) may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fi brosis through an un-explored mechanism.