Nck influences preosteoblastic/osteoblastic migration and bone mass
Nck influences preosteoblastic/osteoblastic migration and bone mass
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DOI：
10.1073/pnas.1518253112
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发表时间：
2015-11
期刊：
影响因子：
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通讯作者：
Smriti Aryal A.C;K. Miyai;Y. Izu;T. Hayata;T. Notomi;M. Noda;Y. Ezura
中科院分区：
文献类型：
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作者：
Smriti Aryal A.C;K. Miyai;Y. Izu;T. Hayata;T. Notomi;M. Noda;Y. Ezura
随着老龄化人口的激增，骨质疏松症是世界范围内的一个主要健康问题。然而，参与骨重建调控的分子仍不完全清楚。NCK(酪氨酸激酶非催化区)是连接细胞骨架和细胞运动的接头分子。我们现在发现，Nck在体外和体内调节细胞迁移，并通过骨形成活动调节骨量。NCK对骨损伤的修复有积极的调节作用。这一发现为理解骨重建提供了独特的见解。成骨细胞系中的细胞迁移，包括成骨前细胞和成骨细胞，已被认为影响骨形成。然而，连接成骨细胞前/成骨细胞迁移和骨形成的分子基础还不完全清楚。NCK(非催化酪氨酸激酶区域，统称为NCK1和NKK2)是调节细胞迁移和细胞骨架结构的信号适配器的一员，但它在成骨细胞系中的功能尚不清楚。因此，我们研究了NCK在这些细胞迁移中的作用。NCK在成骨前细胞/成骨细胞中表达，它的敲除抑制了细胞的迁移、细胞的扩散和对底物的附着。相反，NKK1的过度表达增强了扩散，增加了迁移和附着。在信号方面，NCK双基因敲除抑制了向IGF1(胰岛素样生长因子1)的迁移。在这些细胞中，基于使用抗Nck和抗IRS-1抗体的免疫沉淀实验，Nck 1与IRS-1(胰岛素受体底物1)结合。在体内，NCK基因敲除抑制了DII标记的前成骨细胞/成骨细胞在颅骨缺损处的颗粒扩大。遗传学实验表明，在成骨细胞中有条件地双重缺失Nck-1和Nck-2会导致骨量减少。在这些小鼠中，NCK双重缺乏会抑制体内骨形成速度等骨形成参数的水平。有趣的是，骨吸收参数不受影响。最后，NCK缺乏抑制了骨髓切除后骨损伤的修复。这些结果表明，Nck调节成骨细胞前/成骨细胞迁移和骨量。
Significance Osteoporosis is a major health problem worldwide, as the aging population is soaring. However, molecules involved in the regulation of bone remodeling are still incompletely understood. Nck (noncatalytic region of tyrosine kinase) is an adaptor molecule linking cytoskeleton and cell motility. We now identify that Nck regulates cell migration in vitro as well as in vivo and regulates bone mass via bone formation activity. Nck positively regulates repair of bone injury. This discovery provides a unique insight into the understanding of bone remodeling. Migration of the cells in osteoblastic lineage, including preosteoblasts and osteoblasts, has been postulated to influence bone formation. However, the molecular bases that link preosteoblastic/osteoblastic cell migration and bone formation are incompletely understood. Nck (noncatalytic region of tyrosine kinase; collectively referred to Nck1 and Nck2) is a member of the signaling adaptors that regulate cell migration and cytoskeletal structures, but its function in cells in the osteoblastic lineage is not known. Therefore, we examined the role of Nck in migration of these cells. Nck is expressed in preosteoblasts/osteoblasts, and its knockdown suppresses migration as well as cell spreading and attachment to substrates. In contrast, Nck1 overexpression enhances spreading and increases migration and attachment. As for signaling, Nck double knockdown suppresses migration toward IGF1 (insulin-like growth factor 1). In these cells, Nck1 binds to IRS-1 (insulin receptor substrate 1) based on immunoprecipitation experiments using anti-Nck and anti–IRS-1 antibodies. In vivo, Nck knockdown suppresses enlargement of the pellet of DiI-labeled preosteoblasts/osteoblasts placed in the calvarial defects. Genetic experiments indicate that conditional double deletion of both Nck1 and Nck2 specifically in osteoblasts causes osteopenia. In these mice, Nck double deficiency suppresses the levels of bone-formation parameters such as bone formation rate in vivo. Interestingly, bone-resorption parameters are not affected. Finally, Nck deficiency suppresses repair of bone injury after bone marrow ablation. These results reveal that Nck regulates preosteoblastic/osteoblastic migration and bone mass.