MicroRNA Expression in Cutaneous Lupus: A New Window to Understand Its Pathogenesis

The role of miRNAs in the pathogenesis of cutaneous lupus has not been studied.

It was to assess the levels of a selected panel of circulating miRNAs that could be involved in the regulation of the immune response, inflammation, and fibrosis in cutaneous lupus.

It was a cross-sectional study. We included 22 patients with subacute (SCLE) and 20 with discoid (DLE) lesions, and 19 healthy donors (HD). qRT-PCR for miRNA analysis, flow cytometry in peripheral blood, and skin immunohistochemistry were performed to determine the distribution of CD4 T cells and regulatory cells and their correlation with circulating miRNAs.

miR-150, miR-1246, miR-21, miR-23b, and miR-146 levels were downregulated in SCLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE γ ⁺ with miR-1246 in SCLE, whereas CD123⁺/CD196⁺/IDO⁺ cells were positively associated with miR-150 in DLE. In the tissue, CD4⁺/IL-4⁺ and CD20⁺/IL-10⁺ cells were positively associated with miR-21 and CD4⁺/IFN-γ ⁺ with miR-1246 in SCLE, whereas CD123⁺/CD196⁺/IDO⁺ cells were positively associated with miR-150 in DLE. In the tissue, CD4⁺/IL-4⁺ and CD20⁺/IL-10⁺ cells were positively associated with miR-21 and CD4⁺/IFN-β, thyroid hormone, and cancer signaling pathways were shared between miR-21, miR-31, miR-23b, miR-146a, miR-1246, and miR-150.

A downregulation of miR-150, miR-1246, and miR-21 in both CLE varieties vs. HD. miR-150, miR-1246, and miR-21 levels were downregulated in DLE.