Bone-protective functions of netrin 1 protein

Kenta Maruyama, Takahiko Kawasaki, Masahide Hamaguchi, Motomu Hashimoto, Moritoshi Furu, Hiromu Ito, Takao Fujii, Naoki Takemura, Thangaraj Karuppuchamy, Takeshi Kondo, Takumi Kawasaki, Masahiro Fukasaka, Takuma Misawa, Tatsuya Saitoh, Yutaka Suzuki, Mikaël M. Martino, Yutaro Kumagai, Shizuo Akira

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25 Citations (Scopus)


Netrin 1 was initially identified as an axon guidance factor, and recent studies indicate that it inhibits chemokine-directed monocyte migration. Despite its importance as a neuroimmune guidance cue, the role of netrin 1 in osteoclasts is largely unknown. Here we detected high netrin 1 levels in the synovial fluid of rheumatoid arthritis patients. Netrin 1 is potently expressed in osteoblasts and synovial fibroblasts, and IL-17 robustly enhances netrin 1 expression in these cells. The binding of netrin 1 to its receptor UNC5b on osteoclasts resulted in activation of SHP1, which inhibited VAV3 phosphorylation and RAC1 activation. This significantly impaired the actin polymerization and fusion, but not the differentiation of osteoclast. Strikingly, netrin 1 treatment prevented bone erosion in an autoimmune arthritis model and age-related bone destruction. Therefore, the netrin 1-UNC5b axis is a novel therapeutic target for bone-destructive diseases.
Original languageEnglish
Pages (from-to)23854-23868
Number of pages15
JournalJournal of Biological Chemistry
Issue number46
Publication statusPublished - 11 Nov 2016

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