[The expression of the type I interferon system in muscle and lung of autoimmune myositis rat model]

To investigate the expression levels of the type I IFN system in muscle and lung of experimental autoimmune myositis (EAM) model and to evaluate whether the type I IFN system associates with the pathogenesis of the EAM model in rats.

The EAM model was established to determine creatine kinase (CK) in blood serum. The pathology of muscle and lung tissue was examined by hematoxylin-eosin staining. The concentration of type I IFN system mRNA in muscle and lung tissue was detected by real-time PCR.

The concentration of CK in model group [(209.17 ± 91.95) IU/L] was significantly higher than that of two control groups (P < 0.05). The scores of muscle and lung in EAM model were significantly higher than that of control groups (all P < 0.05). The expression levels of the type I IFN system in muscle of EAM model were significantly higher than that of control groups (all P < 0.05). The expression levels of the type I IFN system in muscle with EAM model were positively correlated with CK and the scores of muscle (all P < 0.05). The expression levels of IFNα, IFNβ, IFNαR1, signal transducer and activator of transcription 1 (STAT1), myxovirus resistance protein 1 (MX1) in lung of EAM model were significantly higher than those of control groups (P < 0.05), but not seen in INF-induced protein with tetratricopeptide repeats 1 (IFIT1) and IFN-stimulated gene 15 (ISG15). The expression levels of IFNα, IFNβ, IFNαR1, STAT1 and MX1 in lung with EAM model were positively correlated with the scores of lung pathology (all P < 0.05).

The type I IFN system probably played a crucial role in the pathogenesis and the pathology of muscle and lung of EAM model.