IGF2BP3-mediated m6A modification of RASGRF1 promoting joint injury in rheumatoid arthritis [RIP-seq]
With the deepening of epigenetic research, more and more studies have shown that N6- methyladenosine (m6A) is closely related to the occurrence and development of rheumatoid arthritis (RA), but the specific mechanism still needs to be further elucidated. In the study, we collected synovial tissues from normal controls and patients with OA or RA. The levels of m6A and inflammation were analyzed by immunofluorescence and western blot. The role of IGF2BP3 in cell proliferation and inflammatory activation was explored using transfection and RNA immunoprecipitation assays. IGF2BP3-/- mice were established, which were used to construct a mouse model of arthritis by transferring serum from adult arthritis K/BxN mice. Histological analysis and micro-CT were performed to determine joint damage. m6A level was markedly increased in RA patients and mouse models, and the expression of IGF2BP3 was upregulated in RA and related to inflammatory markers. IGF2BP3 played an important part in RA-fibroblast-like synoviocytes (FLS) by promoting cell proliferation, migration, invasion, inflammatory cytokine release, and inhibiting autophagy. In addition, IGF2BP3 inhibited autophagy to reduce the production of ROS, thereby decreasing inflammatory activation in macrophages. More importantly, RASGRF1-mediated mTORC1 activation played a crucial role in the ability of IGF2BP3 to promote cell proliferation and inflammatory activation. Based on the arthritis model of IGF2BP3-/- mice, IGF2BP3 knockdown Inhibited RA-FLS proliferation and inflammatory infiltration, and further improved RA joint injury. Our study revealed the important role of IGF2BP3 in RA progression. The targeted inhibition of IGF2BP3 reduced cell proliferation and inflammatory activation and limited RA development in a mouse model of arthritis, providing a potential strategy for RA therapy. Overall design: RIP-seq of synovial tissue in OA or RA patients