Fucoidan Prevents RANKL-Stimulated Osteoclastogenesis and LPS-Induced Inflammatory Bone Loss via Regulation of Akt/GSK3?/PTEN/NFATc1 Signaling Pathway and Calcineurin Activity.
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ABSTRACT: Excessive osteoclast differentiation and/or function plays a pivotal role in the pathogenesis of bone diseases such as osteoporosis and rheumatoid arthritis. Here, we examined whether fucoidan, a sulfated polysaccharide present in brown algae, attenuates receptor activator of nuclear factor-?B ligand (RANKL)-stimulated osteoclastogenesis in vitro and lipopolysaccharide (LPS)-induced bone resorption in vivo, and investigated the molecular mechanisms involved. Our results indicated that fucoidan significantly inhibited osteoclast differentiation in RANKL-stimulated macrophages and the bone resorbing activity of osteoclasts. The effects of fucoidan may be mediated by regulation of Akt/GSK3?/PTEN signaling and suppression of the increase in intracellular Ca2+ level and calcineurin activity, thereby inhibiting the translocation of nuclear factor-activated T cells c1 (NFATc1) into the nucleus. However, fucoidan-mediated NFATc1 inactivation was greatly reversed by kenpaullone, a GSK3? inhibitor. In addition, using microcomputer tomography (micro-CT) scanning and bone histomorphometry, we found that fucoidan treatment markedly prevented LPS-induced bone erosion in mice. Collectively, we demonstrated that fucoidan was capable of inhibiting osteoclast differentiation and inflammatory bone loss, which may be modulated by regulation of Akt/GSK3?/PTEN/NFATc1 and Ca2+/calcineurin signaling cascades. These findings suggest that fucoidan may be a potential agent for the treatment of osteoclast-related bone diseases.
SUBMITTER: Lu SH
PROVIDER: S-EPMC6627629 | biostudies-literature | 2019 Jun
REPOSITORIES: biostudies-literature
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