Comprehensive analysis of bone formation and its application

本研究主要探讨以下问题。1)成骨细胞分化调控因子分析；2)间充质干细胞的建立与表征；3)骨组织的进化变化。本研究结果如下：1)成骨细胞分化调控因子分析a)我们建立runx2缺陷细胞系，通过其他转录因子如Dlx5和Msx2，证实BMP-2在这些细胞中诱导成骨细胞分化。b)CCN3 （NOV）通过与BMP和Notch信号通路相互作用抑制成骨细胞分化。c)我们揭示了Msx2在成骨细胞分化中的重要作用。2)间充质干细胞的建立与表征a)从人错构瘤中建立间充质干细胞，并表征其向多种间充质细胞的分化能力；b)从人骨肉瘤细胞系中建立多能间充质细胞系，其向成骨细胞、软骨细胞和脂肪细胞的分化能力不同；c)我们研究了多能间充质细胞的分化能力。结果表明，CCN3能抑制成骨细胞的分化。3)骨组织的进化变化)我们证明，与哺乳动物相比，青蛙长骨的软骨内成骨明显延迟。这是由于带状刺猬在青蛙中的表达谱与印度刺猬在小鼠长骨中的表达谱不同所致。b)建立了分离青蛙肌肉细胞和软骨细胞的细胞培养方法。c)我们比较了青蛙和小鼠的骨再生过程。与小鼠相比，骨再生过程明显延迟。d)我们研究了蛙类骨骼是否在钙储层中起重要作用，认为蛙类骨骼不会参与钙储层。这些结果将为建立骨再生和骨质疏松症的新疗法提供重要信息。少

We investigate the following issues in this research. 1)Analyses of regulatory factors of osteoblast differentiation, 2)Establishment and characterization of mesenchymal stem cells, 3)Evolutional changes of skeletal tissues. Results in this study is as follow.1)Analyses of regulatory factors of osteoblast differentiationa)We established runx2-deficient cell lines, and demonstrate that osteoblast differentiation is induced by BMP-2 in these cells by using other transcription factors such as Dlx5 and Msx2. b)CCN3 (NOV) inhibits osteoblast differentiation by interacting with BMP and Notch signaling pathways. c)We revealed the important role of Msx2 in osteoblast differentiation.2)Establishment and characterization of mesenchymal stem cellsa)We established mesenchymal stem cells from human hamartoma, and characterized their differentiation potencies into various mesenchymal cells, b)We established multipotent mesenchymal cell lines form human osteosarcoma cell lines, which exhibited differ … More entiation potential into osteoblasts, chondrocytes, and adipocytes, c)We investigated the differentiation potential of multipotent KUSA cells, which were isolated from murine bone marrow, and revealed that CCN3 inhibits osteoblast differentiation in this cell line.3)Evolutional changes of skeletal tissuesa)We demonstrated that endochondral ossification is delayed prominently in frog long bones, compared with that in mammals. This was caused by the different expression profiles of Banded Hedgehog in frog, compared with expression profiles of Indian Hedgehog in mouse long bones. b)We established cell culture methods for muscle and chondrocytes isolated frogs. c)We compared the bone regeneration process between frog and mouse. Bone regeneration process was extremely delayed, compared with that of mouse. d)We investigated whether bones in frogs play important role in calcium reservoir, and suggested that the bones in frogs will not be involved in calcium reservoir.These results will provide important information to establish new therapies for bone regeneration and osteoporosis. Less