Intervention Of Mouse STGF-beta RII、sIL-13Rα2Receptor Protein On Cellular Signal Transduction In Hepatic Fibrosis Of Schistosomiasis Japonicum

Objective: Prokaryotic expression and purification of sTGF-β1RII、sIL-13Rα2protein,and to investigate the effects of the protein on its signal transduction pathway in hepaticfibrosis of schistosomiasis japonica in mouse.Methods:Total RNA was extracted from murine3T3cells for amplification of thetarget gene by RT-PCR. We constructed the prokaryotic expression system ofsTGF-β1RII、sIL-13Rα2protein with E. coli BL21. The recombinant protein waspurified by His-bind protein purification kit. Its antigenicity was identified by Westernblot. BALB/C female mice (6-8w,body weight18-22g) were randomly divided intoeight groups (n=6). In addition to the normal control group, each of other groups werechallenged percutaneously with18±2cercariae of Schistosoma japonicum, and weretreated by intraperitoneal injection every other day from wk5to wk6. As follows: A：the normal control group; B：model group (0.5ml of saline/mouse); C：sIL-13Rα2protein low-dose group(50μg/mouse); D：sIL-13Rα2protein high-dose group (100μg/mouse); E：sTGF-β1RII protein low-dose group(2μg/mouse); F：sTGF-β1RII proteinhigh-dose group(20μg/mouse); G：combined treatment group(sTGFβ1RII10μg/mouse +sIL-13Rα275μg/mouse); H：sTGF-β1RII protein low-dose long course(treatment fromwk5to wk8)of group(2μg/mouse). Mice were sacrificed by cervical dislocation on8weeks after infection. Hepatic hydroxyproline (HYP) was detected by alkaline lysis; thearea of egg granuloma and degree of hepatic fibrosis were observed via HE and Massonstainings. Lung HYP was detected by alkaline lysis(A、B、D、Egroup); the degree ofhepatic fibrosis were observed via Masson stainings. The expression of Smads3andSTAT6protein were measured by immunohistochemical staining.Result:The sTGF-β1RII、sIL-13Rα2gene was cloned and expressed in E. coli BL21successfully. The purified recombinant protein showed specific reaction with itsmonoclonal antibody by Western blotting. When8weeks after infected, the level ofHYP、the area of egg granuloma and degree of hepatic fibrosis in each protein treatmentgroup was significantly lower than the model group (P<0.01); There were nostatistically differences between sTGF-β1RII protein high and low dose group、sIL-the13Rα2protein high and low dose group; The level of HYP and degree of hepaticfibrosis in sTGF-β1RII protein low-dose long course of group was significantly lowerthan the low-dose group (P<0.01), but the area of egg granuloma was no statisticallydifferences; There were no statistically differences in improving the degree of fibrosisbetween sIL-13Rα2protein high and low dose group、sTGF-β1RII protein high dosegroup and combined treatment group, while the level of HYP and the area of egggranuloma(P<0.05)、degree of hepatic fibrosis(P<0.01) in sTGF-β1RII protein low-dosegroup was lower than the combined treatment group. There were no statisticallydifferences in the level of HYP and degree of lung fibrosis between the extracted mousegroup; The expression of its Smads3or STAT6in protein treatment group wassignificantly lower than the model group, there were no statistically differences betweenprotein high and low dose group, but the expression of Smads3in sTGF-β1RII proteinlow-dose long course of group was significantly lower than its low-dose group (P<0.01).Conclusion: In this study, we have obtained the anticipated sTGF-β1RII protein andsIL-13Rα2protein, the recombinant protein was confirmed with good antigenicity; Theprotein can reduce hepatic granuloma size of Schistosomiasis japonica、improve thedegree of hepatic fibrosis and lower the expression of the downstream signaling proteinin the corresponding signal transduction pathway, at the same time it does not producelungs fibrosis in mice; Combination therapy is superior to medication alone in theantifibrotic.