[Tacrolimus down-regulates the mRNA levels of IL-17 and IL-23 in the muscle tissues of mice with experimental autoimmune myositis].

Objective: To measure the expression levels of interleukin-17( IL-17) and IL-23 mRNAs in the muscle tissue of the mice with experimental autoimmune myositis( EAM),and investigate the impact of tacrolimus( TAC) treatment on the mRNA levels of IL-17 and IL-23 and its therapeutic effect in EAM mice.

Methods: Fifteen female BALB / c mice were divided randomly into three groups,a normal control group,an EAM model group and a TAC-treated group. HE staining was used to observe the pathological changes for evaluating muscle inflammation of EAM mice. The expression levels of IL-17 and IL-23 mRNAs in the muscle tissues were measured by real-time fluorescence quantitative PCR. Then the correlations between the pathological changes and the expressions of IL-17 and IL-23 mRNAs were analyzed by Pearson methods.

Results: Compared with the normal controls,the mRNA levels of IL-17 and IL-23 were significantly up-regulated in the EAM model group,and they were down-regulated obviously after TAC treatment. Moreover,the mRNA levels of IL-17 and IL-23 had a significantly positive correlation with the pathological score of the muscle tissues. Compared with the EAM model group,the pathological score of the muscle tissues decreased in the TAC-treated group.

Conclusion: TAC can down-regulate mRNA levels of IL-17 and IL-23 in the EAM mice.