Abstract
The aim of this study was to investigate the relationship between osteoporosis and osteoarthritis by analyzing the DNA methylation in osteoporosis and osteoarthritis. The cancellous bone specimens were collected from a total of 12 hospitalized patients and divided into the osteoporosis group (OA), the osteoarthritis group (OP), the osteoporosis combined with osteoarthritis group (OA & OP), and the normal control group (N). The cancellous bone specimens of each group were detected and the differences in gene expression profiles by the MeDIP-chip technique were compared. Compared with Group OA & OP, the methylation levels in Group OA and Group OP were statistically higher, P < 0.05. In the microarray analysis, a total of 1,222 sites occurred hypermethylation. The analysis targeting the differentially expressed genes between Group OA & OP and Group N revealed that group OA and group OP had 4 common genes: PPIL3, NIF3L1, SMTN, and CALHM2. The level of genomic methylation is lower in the patients with osteoporosis and/or osteoarthritis. The common difference between osteoarthritis and osteoporosis is reflected in some specific promoters, which may participate in the processes of diseases through different pathways.