Elucidation of molecular mechanisms of osteoclastogenesis and its application for bone disease therapy

阐明破骨细胞生成的分子机制及其在骨病治疗中的应用

• 批准号: 16390428
• 负责人: INOUE Jun-ichiro
• 金额: $ 9.15万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390428/
• 关键词: RANK; CD40; TRAF6; osteoclast; NFAT; リウマチ; 骨粗鬆症; 創薬

RANK and CD40 activate NF-kB and MAPKs to similar levels via TRAF6. Even though overexpression of TRAF6 results in osteoclast formation, RANK but not CD40 promotes osteoclastogenesis. To understand the molecular basis for RANK-specific activity in osteoclastogenesis, we created an osteoclast formation system driven by antihuman CD40 antibody-mediated stimulation of a chimeric receptor, h40/mRK, which consists of the extra cellular domain of human CD40 and the transmembrane and cytoplasmic domains of mouse RANK. By introducing mutations into three TRAF6-binding sites of RANK, we found that h40/mRK with a single TRAF6-binding site efficiently induced Ca2+ oscillation and expression of NFATc1, a master switch in osteoclastogenesis, whereas CD40 carrying a single TRAF6-binding site did not. However, expression of CD40 that was approximately 100 times greater than that of h40/mRK resulted in osteoclast formation, indicating that the RANK-TRAF6 signal is more potent than the CD40-TRAF6 signal in terms of NFATc1 activation and osteoclastogenesis. These results suggest that RANK may harbor a specific domain that amplifies TRAF6 signaling. To identify the specific domain, we have introduced various deletion into the cytoplasmic domain of RANK. We found a deletion mutant that can activate NF-kB and MAPKs but can not generate ostesoclasts. The domain missing in this mutant is highly conserved among various species, suggesting that the domain could be critical in TRAF6 activation required for osteoclastogenesis. We are currently focusing on this domain.

RANK和CD40通过TRAF6激活NF-kB和MAPKs到相似的水平。尽管TRAF6的过表达导致破骨细胞的形成，RANK而不是CD40促进破骨细胞的形成。为了了解破骨细胞发生中RANK特异性活性的分子基础，我们创建了一个由抗人CD40抗体介导的嵌合受体h40/mRK驱动的破骨细胞形成系统，h40/mRK由人CD40的细胞外结构域和小鼠RANK的跨膜和胞质结构域组成。通过将突变引入RANK的三个traf6结合位点，我们发现具有单个traf6结合位点的h40/mRK有效地诱导Ca2+振荡和NFATc1的表达，NFATc1是破骨细胞发生的主要开关，而携带单个traf6结合位点的CD40则没有。然而，CD40的表达约为h40/mRK的100倍，导致破骨细胞形成，这表明在NFATc1激活和破骨细胞形成方面，RANK-TRAF6信号比CD40- traf6信号更有效。这些结果表明RANK可能包含一个特定的区域，可以放大TRAF6信号。为了确定特定的结构域，我们在RANK的细胞质结构域中引入了各种缺失。我们发现一个缺失突变体可以激活NF-kB和MAPKs，但不能产生破骨细胞。该突变体中缺失的结构域在不同物种中高度保守，表明该结构域可能对破骨细胞发生所需的TRAF6激活至关重要。我们目前正专注于这个领域。

项目成果

TIFAB inhibits TIFA, TRAF-interacting protein with a forkhead-associated domain

TIFAB 通过叉头相关结构域抑制 TIFA、TRAF 相互作用蛋白

• 发表时间: 2004
• 期刊: Biochem.Biophys.Res.Commun. 317
• 作者: Matsumura;T. et al.
• 通讯作者: T. et al.

Cutting Edge : TNF Receptor-Associated Factor (TRAF) 6 is Essential for Myeloid Differentiation Factor (MyD) 88-Dependent Pathway but Not Toll/IL-1 Receptor Domain-Containing Adaptor Inducing IFN-β (TRIF)-Dependent Pathway in Toll-like Receptor Signaling

最前沿：TNF 受体相关因子 (TRAF) 6 对于骨髓分化因子 (MyD) 88 依赖性途径至关重要，但对于 Toll 中诱导 IFN-β (TRIF) 依赖性途径的含有 Toll/IL-1 受体结构域的接头不是必需的就像受体信号转导

• 发表时间: 2004
• 期刊: J.Immunol. 173
• 作者: Gohda;J. et al.
• 通讯作者: J. et al.

Identification of DRG family regulatory proteins (DFRPs): specific regulation of DRG1 and DRG2

• DOI: 10.1111/j.1365-2443.2005.00825.x
• 发表时间: 2005-02-01
• 期刊: GENES TO CELLS
• 影响因子: 2.1
• 作者: Ishikawa, K;Azuma, S;Inoue, J
• 通讯作者: Inoue, J

RANK-mediated amplification of TRAF6 signaling leads to NFATc1 induction during osteoclastogenesis

• DOI: 10.1038/sj.emboj.7600564
• 发表时间: 2005-02-23
• 期刊: EMBO JOURNAL
• 影响因子: 11.4
• 作者: Gohda, J;Akiyama, T;Inoue, J
• 通讯作者: Inoue, J

Involvement of TNF Receptor-associaetd Factor (TRAF) 6 in IL-25 Receptor Signaling

TNF 受体相关因子 (TRAF) 6 参与 IL-25 受体信号转导

• 发表时间: 2006
• 期刊: J Immunol. 176
• 作者: Maezawa;Y.
• 通讯作者: Y.