The association between knee synovial methylation and knee osteoarthritis in different ethnic populations from different altitude

Abstract

Abstract Objective: To determine genome-wide DNA methylation profiles of knee cartilage from patients with osteoarthritis (OA) at different altitudes. Method: Twenty-four synovial tissue samples were selected. OA synovial tissue samples were obtained from 10 Tibetan OA patients at high altitude and 8 Han OA patients at low altitude. Six normal synovial tissue samples were used as the control group. Illumina Methylation Analyzer package was employed for identifying differentially methylated CpG sites.GO, Pathway and disease annotation enrichment analysis were performed for differential genes corresponding to differential methylation sites. Results: In high-altitude osteoarthritis patients and normal controls, 413 methylation differential sites were associated with osteoarthritis, including 92 hypermethylated sites and 321 hypomethylated sites. In low-altitude osteoarthritis patients and normal controls, 723 methylation differential loci were associated with osteoarthritis, including 436 hypermethylated loci and 297 hypomethylated loci. There were 60 different loci in patients with osteoarthritis at different altitudes. Conclusions: This multistage study identified an interferon-inducible gene interaction network associated with OA and highlighted the importance of gene in OA pathogenesis. The results enhanced our understanding of the important role of DNA methylation in pathology of OA.