MicroRNAs in pemphigus and pemphigoid diseases

Autoimmune blistering diseases are a heterogenous group of dermatological disorders characterized by blisters and erosions of the skin and/or mucous membranes induced by autoantibodies against structural proteins of the desmosome or the dermal-epidermal adhesion complex including the hemidesmosome. They consist of the two major disease groups, pemphigus and pemphigoid diseases (PPDs). The diagnosis is based on clinical findings, histopathology, direct immunofluorescence, and detection of circulating autoantibodies. The pathogenesis is not fully elucidated, prognostic factors are lacking, and to date, there is no cure for PPDs. MicroRNAs (miRNAs) represent small, non-coding RNAs that play a pivotal role in the posttranscriptional regulation of gene expression. Their dysfunction was highlighted to play a significant role in the pathogenesis of various diseases. Even though a link between miRNAs and autoimmune blistering diseases had been suggested, the research of their involvement in the pathogenesis of PPDs is still in its infancy. miRNAs hold promise for uncovering new layers in the pathogenesis of PPDs, in order to improve diagnosis and also to develop potential therapeutic options. In the current article, we provide an overview regarding current knowledge of miRNAs in terms of complex pathogenesis of PPDs, and, also, their potential role as biomarkers, predictive factors and therapeutic targets.