Study of roles of receptor tyrosine kinases in regulating osteoclast function.

受体酪氨酸激酶在调节破骨细胞功能中的作用研究。

基本信息

批准号：
09470393
负责人：
KUMEGAWA Masayoshi
金额：
$ 5.12万
依托单位：
Meikai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

This project was undertaken to elucidate the mechanism for regulation of osteoclast function at molecular level. To address the aim, we first needed a pure population of functional osteoclasts, and succeeded in developing a new method for isolation of mature osteoclasts. Using the isolated osteoclasts, we focused on elucidating the roles of receptor tyrosine kinases in the regulation of osteoclastic function. In this study, we cloned eight receptor tyrosine kinases, including fibroblast growth factor receptor-1(FGFR-1),Tyro3, vascular epithelial growth factor receptors(Fit-1 and Flk-1), insulin receptor, c-fms, and c-met, expressed on mature osteoclasts. Besides these receptor tyrosine kinases, we also detected some receptor serine/threonine kinases such as a subtype of prostaglandin (PG) E2 receptor, EP4 and Bone morphogenetic receptors (BMPR-IA and BMPR-II) in osteoclasts. We found the signaling through FGFR-1,Tyro3, and VEGF receptors stimulated the osteoclastic bone resorption and/or the osteoclast survival. These receptors associated with c-src, FAK, P13K, and 42/44p MAPKs to express the stimulatory effects. On the other hand, PGE2 inhibited the osteoclastic bone-resorbing activity through the EP4 receptor coupled with Gs-protein, whereas BMP-2 stimulated the activity through its receptors/Smads. Thus, mature osteoclasts express many receptor tyrosine kinases as well as serine/threonine kinase receptors on their plasma membranes to regulate their functions, and these results provide us a lot of insights to understand the regulatory mechanism for osteoclast.

该项目是为了阐明在分子水平上调节破骨细胞功能的机制。为了解决目标，我们首先需要纯粹的功能性破骨细胞，并成功地开发了一种新的分离成熟破骨细胞的方法。使用分离的破骨细胞，我们专注于阐明受体酪氨酸激酶在调节破骨碎裂功能中的作用。在这项研究中，我们克隆了八个受体酪氨酸激酶，包括成纤维细胞生长因子受体1（FGFR-1），TYRO3，血管上皮生长因子受体（FIT-1和FLK-1），胰岛素受体，C-FMS，C-FMS和C-MET，在成熟的骨质上表达。除了这些受体酪氨酸激酶外，我们还检测到一些受体丝氨酸/苏氨酸激酶，例如前列腺素（PG）E2受体，EP4和骨形态发生受体（BMPR-IA和BMPR-II）的亚型。我们发现通过FGFR-1，TYRO3和VEGF受体的信号刺激了整骨骨吸收和/或破骨细胞的存活。这些与C-SRC，FAK，P13K和42/44p MAPK相关的受体以表达刺激作用。另一方面，PGE2通过EP4受体与GS-蛋白质结合的EP4受体抑制了破骨骨质的活性，而BMP-2通过其受体/SMAD刺激了活性。因此，成熟的破骨细胞表达许多受体酪氨酸激酶以及其质膜上的丝氨酸/苏氨酸激酶受体以调节其功能，这些结果为我们提供了很多见解，以了解骨质细胞的调节机制。