[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.