Specific Autoantibodies and Clinical Phenotypes Correlate with the Aberrant Expression of Immune-Related MicroRNAs in Dermatomyositis

The serum concentrations of miRNAs, miR-23a-3p, miR-23b-3p, miR-146a-5p, miR-146b-5p, and miR-150-5p, were shown to be associated with the immune and inflammatory progressions. We assessed the expressions of these five miRNAs in association with clinical phenotypes and myositis-specific autoantibody-defined subgroups of dermatomyositis (DM).

The results suggest an association between the four immune-related microRNAs and different clinical immune-phenotypes, and this association may regulate the complexity of disease processes through multipathways in DM patients.

The present study included 49 patients with DM and 30 healthy controls. The serum concentrations of miR-23a-3p, miR-23b-3p, miR-146a-5p, miR-146b-5p, and miR-150-5p were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Associations between the serum concentrations of miRNAs and DM clinical immune phenotypes were examined as well.

The serum concentrations of miR-23b-3p, miR-146a-5p, and miR-150-5p were significantly downregulated in DM patients (P < 0.001, P < 0.001, and P = 0.002, respectively), while miR-146b-5p was remarkably upregulated in DM patients compared with healthy controls (P = 0.039). Similarly, the expressions of miR-23b-3p, miR-146a-5p, and miR-150-5p were significantly downregulated in the peripheral blood mononuclear cells (PBMCs) from DM patients. Further study indicated that the serum level of miR-23b-3p was significantly correlated with creatine kinase (CK) (r = -0.286, P = 0.046) and the serum level of miR-146a-5p was evidently correlated with C-reactive protein (CRP) (r = -0.358, P = 0.012). Significant correlations were also observed between the serum levels of miR-146b-5p and CRP (r = -0.347, P = 0.014) and the erythrocyte sedimentation rate (ESR) (r = -0.287, P = 0.046). In addition, the expression level of miR-146b-5p was upregulated in DM complicated by tumors compared with those without tumors (P = 0.001 and P < 0.001, respectively). Especially, miR-150-5p was significantly downregulated in DM patients with anti-MDA5 antibodies and anti-NXP2 antibodies compared with those without (P = 0.017 and P = 0.047, respectively). No significant differences were observed between the four serum microRNAs in patients with and without interstitial lung diseases (all P > 0.05).