| First Author | Yang J | Year | 2008 |
| Journal | Eur J Immunol | Volume | 38 |
| Issue | 6 | Pages | 1598-609 |
| PubMed ID | 18421790 | Mgi Jnum | J:136303 |
| Mgi Id | MGI:3795846 | Doi | 10.1002/eji.200737650 |
| Citation | Yang J, et al. (2008) The 4-1BB ligand and 4-1BB expressed on osteoclast precursors enhance RANKL-induced osteoclastogenesis via bi-directional signaling. Eur J Immunol 38(6):1598-609 |
| abstractText | The 4-1BB is a costimulatory molecule similar to the receptor activator of NF-kappaB ligand (RANKL), both of which are key factors for the differentiation of osteoclasts and are expressed mainly by activated T cells. The 4-1BB shares common signaling pathways with RANK, suggesting a potential role in osteoclastogenesis. In this study, the role of 4-1BB and 4-1BB ligand (4-1BBL) in osteoclastogenesis was investigated using 4-1BB(-/-) and 4-1BB(+/+) mice. Osteoclast precursors normally express 4-1BB and 4-1BBL after exposure to RANKL, which was confirmed by semi-quantitative RT-PCR and flow cytometry. The 4-1BB(-/- )mice had a slightly increased bone mass accompanied by a reduced osteoclastogenic ability of 4-1BB(-/-) bone marrow-derived macrophages (BMM) ex vivo. In addition, 4-1BB(-/-) BMM demonstrated hypophosphorylation of JNK and p38 and decreased induction of c-Fos in response to RANKL stimulation. Retroviral transduction of wild-type as well as partial-length 4-1BB, which lacks TNF receptor-associated factor 2-binding sites for signaling, restored the osteoclastogenic ability of 4-1BB(-/-) BMM. Furthermore, both recombinant 4-1BB and 4-1BBL enhanced RANKL-induced osteoclastogenesis by 4-1BB(+/+) BMM and the induction of c-Fos and NFATc1.Together, these results indicate that 4-1BBL and 4-1BB expressed on osteoclast precursors enhance RANKL-induced osteoclastogenesis via bi-directional signaling, findings that may delineate the complex nature of the 4-1BBL and 4-1BB interaction.Supporting Information for this article is available at www.wiley-vch.de/contents/jc_2040/2008/37650_s.pdf. |
