Circulating miRNA-21-5p role in the development of orbitopathy in Graves disease

Abstract

BackgroundThe pathogenesis of graves orbitopathy (GO) is complex, with genetic predisposition, environmental factors and epigenetic alterations. Understanding the role of epigenetics including noncoding microribonucleic acids (miRNAs) can give a new information about the pathogenesis and clinical features of disease due to the modulatory effects in the immune system, such as miR-21-5p which affect the balance of T-regulatory (Treg)/Th17 cells. This study was designed to evaluate how the circulating miR-21-5p is involved in the development of orbitopathy in Graves disease (GD) and to assess its diagnostic value. MethodsFive ml of blood obtained from seventy five patients with hyperthyroidism with age range (20‐ –50 year). Only forty patients with positive thyroid stimulating hormone receptor antibody (TSHR-Ab) were involved in this study, in addition to forty healthy subjects as a control group. Patients were divided into groups based on the clinical features (goiter or orbitopathy), family history and treatment state. Patients with orbitopathy were divided based on severity and activity of the disease according to European Group on Graves Orbitopathy (EUGOGO) guidelines. The measurement of circulating miR-21-5p expression was done by real time polymerase chain reaction. ResultsThe expression of circulating miR-21-5p in all patient groups is significantly elevated (p < 0.01) compared with controls. Circulating miR-21-5p expression in patients with orbitopathy shows significant elevation (p = 0.050) in comparison with patients without orbitopathy. Results showed that miR-21-5p is positively correlated with levels of TSH, FT3, FT4, and TSHR-Abs. In conclusion, the up-regulation of miR-21-5p in all patient groups indicating that miR-21-5p can help in the diagnosis of GD and its progression to orbitopathy, miR-21-5p also considered an important molecular target for GD therapy.