Circular RNAs (circRNAs) are a novel class of non-coding RNAs, which are more stable than linear RNAs for their closed circular structure by covalent bond. CircRNAs exist in a large variety of cells and regulate the expressions of target genes. Moreover, circRNAs are closely related to various diseases and have a potential value as biomarkers and prognostic markers clinically. In this article, the classification and biological functions of circRNA molecules (including being as microRNA sponges, regulating gene transcription, regulating RNA binding protein and the potential translation function) are summarized, and the latest research progress of circRNAs in rheumatoid arthritis is reviewed.
Immune-mediated necrotizing myopathy (IMNM) is a type of autoimmune myopathy characterized by relatively severe proximal weakness with high serum muscle enzyme levels, myofiber necrosis with minimal inflammatory cell infiltrate on muscle biopsy, and infrequent extra-muscular involvement. The mechanism of necrotizing myopathy remains unclear. The new European Neuromuscular Centre criteria divides IMNM into three distinct subtypes according to different autoantibodies, which reminds us antibodies may be involved in the pathogenesis of IMNM and different subtypes may have different pathogenesis. This review summarizes the current understanding of the pathogenesis of IMNM.