Increased Expression of the p-STAT3/IL-17 Signaling pathway in patients with Dermatomyositis.

OBJECTIVE To explored the roles of phosphorylated signal transduction and activator of transcription 3 (p-STAT3) and IL (interleukin) -17 in patients with dermatomyositis (DM). METHODS A total of 20 DM patients and 12 healthy controls were enrolled. The Flow cytometry combined with counting was used to detect the numbers of Th17 cells. Western blotting and immunohistochemistry was used to examine the muscle levels of p-STAT3 and IL-17, and serum levels of IL-17 were measured by enzyme-linked immunosorbent assays. RESULTS Muscle p-STAT3 and IL-17 levels, the numbers of Th17 cells, and serum IL-17 levels were markedly increased in DM. p-STAT3 and IL-17 were co-expressed in the muscle of DM patients. The p-STAT3 levels correlated with the number of Th17 cells as well as muscle and serum IL-17 levels. The correlations of the p-STAT3 level with elevated levels of transaminases, myocardial enzymes, and the health assessment questionnaire score were significantly positive, while the correlation with manual muscle testing-8 was significantly negative. A receiver operating characteristic curve indicated good predictive value of p-STAT3 for the occurrence of DM. CONCLUSION The increased p-STAT3/IL-17 signaling pathway activation in DM patients may induce muscle inflammation and necrosis, and it may be a potential target for DM.