Targeting miR-18a sensitizes chondrocytes to anticytokine therapy to prevent osteoarthritis progression.

ABSTRACT: Inflammation participates in the development of OA and targeting inflammatory signaling pathways is a potential strategy for OA treatment. IL-1? is one of the most important inflammatory factors to trigger the activation of NF-?B signaling and accelerate OA progression, whereas OA patients could hardly benefit from inhibiting IL-1? in clinic, suggesting the importance to further explore the details of OA inflammation. We here showed that expression of miR-18a in chondrocytes was specifically induced in response to IL-1? in vitro as well as in rat model of OA during which NF-?B signaling was involved, and that nuclear-translocated p65 directly upregulated miR-18a expression at transcriptional level. Further, increased miR-18a mediated hypertrophy of chondrocytes, resulting in OA degeneration, by targeting TGF?1, SMAD2, and SMAD3 and subsequently leading to repression of TGF-? signaling. And the level of serum miR-18a was positively correlated to severity of OA. Interestingly, other than IL-1?, pro-inflammation cytokines involving TNF? could also remarkably upregulate miR-18a via activating NF-?B signaling and subsequently induce chondrocytes hypertrophy, suggesting a pivotal central role of miR-18a in inflammatory OA progression. Thus, our study revealed a novel convergence of NF-?B and TGF-? signaling mediated by miR-18a, and a novel mechanism underlying inflammation-regulated OA dependent of NF-?B/miR-18a/TGF-? axis. Notably, in vivo assay showed that targeting miR-18a sensitized OA chondrocytes to IL-1? inhibitor as targeting IL-1? and miR-18a simultaneously had much stronger inhibitory effects on OA progression than suppressing IL-1? alone. Therefore, the diagnostic and therapeutic potentials of miR-18a for OA were also revealed.

SUBMITTER: Lian C 

PROVIDER: S-EPMC7609664 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature