Identification of Key Extracellular Proteins and miRNAs for Use as Diagnostic Biomarkers of Temporomandibular Joint Osteoarthritis

Abstract Background : Temporomandibular joint osteoarthritis (TMJ-OA) is an inflammatory disease that is pathologically characterized by the destruction of cartilage and subchondral bone. During the progression of TMJ-OA, the concentration of some extracellular proteins (EPs) in the synovial fluid are altered in the inflammatory environment. Micro RNAs formed an important epigenetic regulation mode during disease progression, which were secreted by cells by means of vesicles then regulated gene transcription. However, the relationship among these proteins, micro RNAs and inflammation was still unclear. Methods : In this study, bioinformatics tools were used to compare the expression profiles of synovial membranes from human TMJ-OA samples and normal TMJ samples. Results : Four genes, including MMP2, FN1, TIMP1, and APOE were identified as hub EPGs. Four miRNAs were identified as key differentially expressed miRNAs (kDEMs) and formed a miRNA-mRNA network with four hEPGs. Furthermore, after stimulation of chondrocytes and SW982 cells with IL-1β in vitro, the gene and protein expression levels of the hEPGs were increased and the four kDEMs were decreased compared with those in the normal group. Conclusion : The study of differentially expressed EPs and miRNAs in TMJOA is of great significance for clinical diagnosis and treatment.