Biomarkers in Adult Dermatomyositis: Tools to Help the Diagnosis and Predict the Clinical Outcome

Figure 2

Targets and the simplified downstream effects of their autoantibodies encountered during dermatomyositis. (a) MDA5 recognizes the long double-strand RNA leading through the RIG1-MDA5 pathway to the cleavage of the mitochondrial antiviral signaling protein (MAVS), the nuclear translocation of NF-κB, and the production of type I interferon. (b) Transfer RNA (tRNA) (Jo-1, PL-7, PL-12, EJ, OJ, KS, Zo, and Ha) helps the ribosome-recruiting aminoacyl to the site of translation. (c) Small ubiquitin-like modifier-activating enzymes (SAEs) are members of an enzyme complex leading to the SUMOylation of targeted proteins leading to either their translocation to the nucleus or the inhibition of transcription. (d) Mi-2 is a component of the nucleosome remodeling deacetylase complex (NuRD) which actively deacetylates histones leading to the compaction of chromatin and subsequently to the inhibition of transcription. (e) The nuclear matrix protein 2, which localizes in the promyelocytic leukemia (PML) nuclear bodies, binds to mRNA in the nucleus and can subsequently lead to RNA metabolism inhibition. Transcription intermediary factor family antigens have been deliberately omitted in this figure due to their broad mechanism of action.

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