The role of microRNAs in autoimmune diseases with skin involvement.

MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression by binding to the 3' untranslated region (UTR) of target messenger RNAs (mRNAs), which leads to the degradation or translational repression of their target mRNAs. Previous research on miRNAs has revealed a new paradigm of gene regulations and pathways involved in the pathogenesis of autoimmune disorders and malignant diseases. The roles of miRNAs in cellular processes, including cell differentiation, proliferation, apoptosis and immune functions, are not clearly understood. MiRNAs are easily detected in a variety of sources, including tissues, serum and other body fluids, and this make them a good biological sample for pathogenic studies and disease biomarker development. This review encompasses the current understanding of the roles of miRNAs in autoimmunity and the cellular and molecular mechanisms of miRNAs in various autoimmune diseases (AIMDs). Specifically, we focus on the target genes of miRNAs and the biological processes associated with autoimmune diseases with skin involvement, including systemic lupus erythematosus, psoriasis, systemic sclerosis, Behcet's disease and dermatomyositis. In addition, the diagnostic and therapeutic relevance of miRNAs that are involved in autoimmunity are elucidated to provide information for clinical implications.