Polypeptide SJMHE1 plays a therapeutic role in asthmatic mice by regulating miR-21 and miR-17 expression
This study was designed to explore the therapeutic effect of the Schistosoma japonicum-derived peptide SJMHE1 in asthmatic mice and the roles of microRNA-21(miR-21)and miR-17 in this process.Mice were randomly divided into control group,asthma group,asthma+PBS group,and asthma+SJMHE1 group.Asthma model was induced with the ovalbumin(OVA)in mice.Airway inflammation was assessed by histopathologic sections of mouse lungs;bronchoalveolar lavage fluid(BALF)was sorted and counted,and the expression level of OVA-specific IgE in mouse serum was measured by ELISA;the distribution of T helper(Th)cells was analyzed by flow cytometry.qRT-PCR was used to detect the expression of Th-associated transcription factors and cytokines,the levels of miR-21 and miR-17 in the lungs of mice;Western blot was used to detected the protein expression of phosphorylated signal transducer and activator of transcription 3(p-STAT3)and phosphatase and tensin homolog(PTEN).Compared with the control group,mice in the asthma group demonstrated increases in airway inflammation,eosinophil and neutrophil counts in the BALF,serum IgE expression levels(P<0.001),proportions of Th2 and Th17 cells,expressions of related transcripts and cytokines(P<0.05),expression of miR-21 and miR-17(P<0.001),and expression of p-STAT3,while decreases in proportions of Th1 and Treg cells,expression of related transcripts and cytokines,and expression of PTEN.All indicators mentioned above was reversed in mice of the asthma/SJMHE1 group,as compared with the asthma/PBS group.In conclusion,the peptide SJMHE1 regulates Th1/Th2/Th17/Treg cell balance via miR-21 and miR-17,thus plays a therapeutic role in asthmatic mice.