JQ1 Alleviates Liver Damage In Schistosoma Japonicum-infected Mice And Inhibiting Th1 Immune Response

Objective: Liver damage caused by schistosomia infection can lead to serious diseases such as hepatic fibrosis and cirrhosis,while the balance of Th1/Th2 disease response plays an important role in schistosomia infection.This paper mainly explores whether the small molecule compound JQ1 can inhibit the of Schistosoma japonicum by inhibiting Th1 immune response by Jak-STAT.Methods: The mice were randomly divided into three groups(normal group,DMSO-control group,JQ1-treated group),nine in each group.The DMSO-n control group and the JQ1-treated group were infected with 20±2 Schistosoma japonicum,and the two experimental groups were treated with Praziquantel(300 mg/kg/d)for two days in six weeks after infection,after two days of rest,followed by JQ1 treatment begins treated(50 mg/kg/d)for two weeks,while the DMSO-control group injected an equal amount of DMSO-10% β-cyclodextrin.After successful anesthesia and execution of mice,the weight of each mice and weight of liver and spleen were recorded,and then the liver and spleen index of mice was compared;the transcription factor T-bet,pSTAT4 and cytokine IFN-γ content of Th1 cells in mice liver granuloma cells were detected by flow cytometry(FCM)method.The mRNA level of Th1 related factors in liver tissue of mice was detected by real-time fluorescence quantitative PCR(qPCR);the granuloma and fibrosis of different groups were detected by HE staining and Sirius Red staining then statistically analyzed;After stimulation with Jurkat cells plus IL-12,Western-blot assays(JQ1,500 nM/1 μM)were used to detect the expression of pSTAT4/STAT4 and pJak2/Jak2 protein;finally,by inducing differentiation of Th1 cells,tern-blot assays(JQ1,250 nM/500 nM)were used to detect the expression of pSTAT4/STAT4 and pJak2/Jak2 protein.Results: The liver fibrosis model of Schistosoma japonicum in C57 mice was successfully constructed.The liver index and spleen index of mice treated with JQ1 were significantly lower than those of DMSO solvent control group(P < 0.05).Flow cytometry analysis showed that JQ1 treatment group was compared with solvent control.For the group,the ratio of Th1 cells decreased significantly(P < 0.05),and the mean fluorescence intensity of pSTAT4 decreased significantly(P < 0.05).qPCR results showed that the mRNA of Th1 related factor(T-bet,IFN-γ)in JQ1 treatment group was significantly decreased(P < 0.001,P < 0.05);HE staining showed significant improvement in liver granuloma in mice treated with JQ1(P < 0.05);Sirius red staining and hydroxyproline detection showed JQ1 treatment group The fibrosis of mice was significantly improved(P < 0.01).After Jurkat cells were stimulated with IL-12 and treated with JQ1,the results of immunoblotting showed that pJak2 and pSTAT4 decreased with increasing drug concentration(P < 0.05).There was no significant change in Jak2 and STAT4(P > 0.05).The results of Western blotting of Th1 cells showed that pJak2 and pSTAT4 decreased with increasing drug concentration(P < 0.05),and total Jak2 and STAT4 did not change significantly(P > 0.05).Conclusion: The liver fibrosis model of C57 mice caused by Schistosoma japonicum infection was successfully constructed.The experimental analysis showed that the liver indexes of the mice in the JQ1 treatment group were significantly better than those in the solvent control group,indicating that it inhibited the activity of Th1 cells.The mechanism is to inhibit the level of Jak-STAT phosphorylation in Th1 cells.Further cellular experiments have also demonstrated that JQ1 reduces the activity of the Jak-STAT pathway.