Schistosoma Japonicum Infection On The Expression Of Arg-1 And Fizz-1 Protein In Liver Tissue Of Mice With High Fat Diet

Objective Insulin resistance in C57BL/6J mice was induced by high fat diet, further to investigate the effect on macrophages in liver tissue of C57BL/6J obese mouse selective activation and systemic insulin resistance and the possible mechanism post of Schistosoma japonicum infection. Methods 36 male C57BL/6J mice were randomly assigned into 3 groups: normal control(NC, n=12) group, high-fat diet(HF, n=12) group and high-fat diet with schistosoma japonicum infected(HSj, n=12) group. They were fed with basic diet, high-fat diet group, respectively, and HSj group were infected schistosoma japonicum. Specimen was collected 6 and 12 weeks after high-fat diet, separately. The levels of fasting blood glucose(FBG), fasting plasma insulin(FINS) and homeostasis model assessment index for insulin resistance(HOMA-IR) were detected. Interleukin-6(IL-6)、arginase-1(Arg-1) and found in inflammatory zone-1(Fizz-1) m RNA and proteins were detected by semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) and by Immunohistochemical method. Result l Sixth weeks after infection of Schistosoma japonicum cercariae, the body weight of the mice in HF group and HSj group gained 20% compared with the average body weight in NC group,so the obesity model induced HF diet was established successfully. By the end of twelfth weekend post of infection, the weight of mice in HSj group were lower than that in HF group(P<0.05) and NC group(P<0.05), and NC group lower than that of HF group(P<0.05). l Sixth weekend after being Infected, FBG, FINS and HOMA-IR in HF group and HSj group were significantly higher than those in NC group(P<0.05), and the difference of these indices in HF group and HSj group had no statistical significance(P>0.05).At twelfth weekend, FBG, FINS and HOMA-IR in HF group were significantly higher than those in NC group and HSj group(P<0.05), but there were no significant difference of the above indexes in NC group and HSj group(P>0.05).12 weeks after infection,HOMA-IR and FINS in HF group were significantly higher than at 6 weeks(P<0.05); while FBG increased at the 6th week,the difference was not statistically significant(P>0.05).12 weeks post of infection,FBG, FINS and HOMA-IR in HSj group were significantly lower than at 6th week(P<0.05). l AT the sixth weekend,IL-6 m RNA expression detected by RT-PCR in HSj group and HF group were higher than that in NC group(P<0.05), the expression of IL-6m RNA in HF group was significantly higher than that at the twelfth weekend in NC group and HSj group(P<0.05). Infected over the sixth weekend, Arg-1 m RNA expression in HF group and HSj group was lower than that in NC group(P<0.05), and Arg-1 m RNA expression ranged from low to high as group HF, group NC, group HSj by end of twelfth weekend after infection(P<0.05). At sixth weekend, HF group’s Fizz-1m RNA expression was lower than that of HSj group(P<0.05), nevertheless the expression of Fizz-1m RNA between the two groups was opposite(P<0.05). l Using immunohistochemical method to detect the protein of Fizz-1 and IL-6 expression among NC group, HF group and HSj group,there were no statistical difference(P>0.05) at end of sixth week, and the expression of Arg-1 in HF group was higher than that in group of HSj(P<0.05). The expression of IL-6 in HF group posting infection at twelfth weekend was higher than that in both NC group and HSj group(P<0.05); the expression of Arg-1 in HSj group was the highest,and it was least in HF group(P<0.05), so was the trend of Fizz-1 expression. Conclusion l C57BL/6J mouse model of obesity with characteristics of insulin resistance can be established by high fat diet.l The level of inflammatory cytokine IL-6 secreted by M1 macrophages in liver tissues of obese mouse increased while Arg-1 and Fizz-1 M2 macrophages specific marker reduced. there were M1 macrophages polarization in obese mice with insulin resistance. l Schistosoma japonicum infection in advanced may promote M2 macrophages polarization in liver tissue of obese mice,reduce inflammation of the liver(IL-6), and ameliorate insulin resistance.