Research of bone formation signaling in osteoblast

成骨细胞中骨形成信号的研究

基本信息

批准号：
17590961
负责人：
KAJI Hiroshi
金额：
$ 1.86万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590961/
关键词：
oateoblast TGF-beta Smad Menin bone formation parathyroid hormone Mineralization 細胞分化

项目摘要

1 We examined the effects of parathyroid hormone (PTH), the putative potent bone forming reagent, on Smad3 and beta-catenin in osteoblastic cells. PTH and Smad3 induced the expression of beta-catenin. These actions of PTH were through both cAMP and calcium/protein kinase C systems. Moreover, PTH enhanced the transcriptional activity induced by beta-catenin. This PTH-Smad3-beta-catenin signal seemed to be associated with anti-apoptotic effects of PTH in osteoblasts. 2 We have clarified the significance of Smad3 in bone formation. Smad3 suppressed the differentiation into osteoblasts induced by bone morphogenetic protein-2 in mouse mesenchymal ST-2 cells. On the other hand, in mouse osteoblastic MC3T3-E1 cells, the induction of Smad3 on ALP activity and type I collagen expression decreased during differentiation, but the effects of Smad3 on the expressions of Runx2 and osteocalcin converted to induction from suppression during differentiation. Smad3 modulated the expression of other mineralization-related factors. 3 DNA microarray analysis with 45000 genes were performed between control and Smad3-overexpressed MC3T3-E1 cells treated with Erk1/2 inhibitor. The significance of several putative bone formation-related genes including known and unknown genes is being analyzed at the present. The expression vectors of unknown genes were made and their functions are investigated in osteoblasts. 4 MC3T3-E1 cells, which overexpressed Smad7, an inhibitory Smad, were developed. Smad7 suppressed proliferation, differentiation, the production of bone matrix proteins and mineralization in osteoblasts. Moreover, PTH induced the expression of Smad7, suggesting that Smad7 may be the target of the inhibition of bone formation.

1我们检查了甲状旁腺激素（PTH），假定的有效骨形成试剂，对成骨细胞中Smad3和β-catenin的影响。 PTH和SMAD3诱导β-catenin的表达。 PTH的这些作用均通过cAMP和钙/蛋白激酶C系统。此外，PTH增强了β-catenin引起的转录活性。这种PTH-SMAD3-β-catenin信号似乎与成骨细胞中PTH的抗凋亡作用有关。 2我们已经阐明了SMAD3在骨形成中的重要性。 SMAD3抑制了小鼠间充质ST-2细胞中骨形态发生蛋白-2诱导的成骨细胞的分化。另一方面，在小鼠成骨细胞MC3T3-E1细胞中，SMAD3对ALP活性和I型胶原蛋白表达的诱导在分化过程中降低，但是SMAD3对Runx2和骨钙蛋白表达的影响在分化过程中转化为从抑制中转化为诱导的诱导。 SMAD3调节了其他与矿化相关因素的表达。 3在用ERK1/2抑制剂处理的对照和SMAD3过表达的MC3T3-E1细胞之间进行了45000基因的DNA微阵列分析。目前正在分析几种推定的骨形成基因（包括已知和未知基因）的重要性。制作了未知基因的表达载体，并在成骨细胞中研究了其功能。开发了4个MC3T3-E1细胞，过表达Smad7（一种抑制性SMAD）。 SMAD7抑制了扩散，分化，骨基质蛋白的产生和成骨细胞中的矿化。此外，PTH诱导了SMAD7的表达，这表明SMAD7可能是抑制骨形成的靶标。