[Advances in epigenetic markers of dermatomyositis/polymyositis]

Idiopathic inflammatory myopathy (IIM) is a rare group of autoimmune diseases, characterized by chronic muscle weakness, muscle fatigue and infiltration of single nuclear cells in skeletal muscle. Its subtypes include dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and immune-mediated necrotizing myositis (IMNM), and the most common subtypes are DM and PM. PM is an autoimmune disease mainly manifested by muscle damage. When the skin is involved, it is called DM. The incidence of IIM was relatively low, which was 1.16-19 per million people/year, but the mortality was high and the prognosis was poor. The pathogenesis of IIM is still unclear. Previous studies suggest that both immune and non-immune mechanisms are involved in its pathogenesis, especially cellular and humoral immunity. In recent years, researchers have conducted a number of studies on the pathogenesis of IIM, especially in the study of DM/PM with the application of high-throughput biometrics. Epigenetics is a discipline that refers to the genetic phenomena of DNA methylation spectrum, chromatin structure state and gene expression spectrum transferred between cells without any changes in DNA sequence, including DNA methylation, chromatin modification and non-coding RNA changes. A large number of studies have shown that epigenetic modification plays an important role in many diseases, especially in cancer. Recent studies have also found a series of epigenetic markers related to the occurrence and development of DM/PM, mainly in the aspect of non-coding RNA changes, such as miR-10a, miR-206, etc. And there has also been some research on DNA methylation. However, no studies have been reported on whether chromatin modification is involved in the pathogenesis of DM/PM. The pathogenesis of DM/PM is complex and diverse. With the development of research, certain microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) may become biological markers for the early diagnosis of DM/PM. Therefore, this paper mainly expounds the research progress of the biomarkers of DM/PM from the aspect of epigenetics.