NO/p38 MAPK/OPG 信号通路在骺板生长发育中诱导软骨细胞凋亡和促进MSC成骨分化的作用机制研究

The osteoblasts and osteoclasts process in the growth of Epiphyseal plate mainly concentrated in epiphyseal plate calcification growth band, which related to the dynamic balance among the apoptosis of epiphyseal cartilage, osteoblasts (OB) from bone marrow stromal cells (MSC), as well as osteoclast (OC) from monocytes. Nitric oxide (NO) plays an important role in the growth of epiphyseal plate, which participates in the apoptosis of epiphyseal plate through the p38 MAPK pathway, induced bone marrow stromal cell osteogenic differentiation by OPG, and involved in monocyte differentiation to osteoclasts by NF-kB pathway. The current study tries to investigate the mechanism of NO in the epiphyseal plate, OB from MSC, as well as OC from monocytes study the role and the molecular mechanism of NO/p38 MAPK / OPG pathway in MSC osteogenic differentiation and the process of monocytes to osteoclast differentiation. Epiphyseal chondrocytes in vitro osteoclast-induced OB / OC culture experiments to certificate the direct and indirect regulation role and related molecular mechanism of NO/OPG/NF-kB in chondrocyte apoptosis, OB and OC differentiation. Therefore, this study is of great significance in development of the epiphyseal plate line disease （KBD）and development and mechanisms of a variety of metabolic bone disease.

基于骺板生长发育中的钙化带涉及到骺软骨细胞凋亡、源自骨髓基质干细胞（MSC）的成骨细胞(OB)和源自单核细胞的破骨细胞(OC)间的动态平衡；一氧化氮（NO）通过p38 MAPK途径参与骺板软骨细胞凋亡、通过OPG诱导MSC成骨分化和通过NF-kB途径参与单核细胞破骨分化等，但目前的研究未能明确揭示NO在骺板生长发育中的作用机制。本课题以大鼠骺板生长发育障碍模型及骺软骨细胞、MSC、OB和OC为研究对象，采用细胞培养、干细胞诱导分化和基因沉默等技术，系统研究NO在骺板软骨细胞凋亡中的作用机制，研究NO/p38 MAPK/OPG信号通路在MSC成骨分化和单核细胞破骨分化过程中发挥的调节作用及其分子机制；阐明NO/OPG/NF-kB对软骨细胞凋亡、OB和OC分化的直接和间接调控作用及相关分子机制，为大骨节病（KBD）等骺板发育性疾病的研究提供思路。

基于骺板生长发育中的钙化带涉及到骺软骨细胞凋亡、源自骨髓基质干细胞（MSC）的成骨细胞(OB)和源自单核细胞的破骨细胞(OC)间的动态平衡。本研究发现一氧化氮（NO）通过OPG诱导MSC成骨分化，NO通过NF-kB/p38 MAPK途径参与单核细胞破骨分化。因此，本实验发现，在骺板生长发育中，NO/p38 MAPK/OPG信号通路通过促进MSC成骨分化来和促进单核细胞向破骨细胞分化调控骺板生长。.ON/OPG促进大鼠MSC成骨增殖和分化研究。从大鼠股骨分离骨髓基质干细胞，培养并成功传代和鉴定，成功培养大鼠骨髓基质干细胞.本实验发现OPG能促进大鼠骨髓基质干细胞的增殖，并能促进大鼠骨髓基质干细胞活性及分化。本实验发现NO/OGP通过eNOS介导刺激大鼠骨髓基质干细胞的增殖及向成骨细胞分化。.NO/NF-Kb/p38 MAPK通路在单核细胞向破骨细胞分化中作用研究。本实验成功培养单核细胞，成功诱导单核细胞向破骨细胞分化。本实验发现NO对体外培养的单核细胞有促进向破骨细胞分化的作用。研究发现NO通过NF-kB/p38 MAPK介导单核细胞向破骨细胞分化。.因此，NO是骺板成骨过程中的重要调节因子，对骺板软骨细胞、成骨细胞和破骨细胞均具有一定的调节作用。对NO在骺板成骨中的确切作用机制的深入研究，可为各种骨骼生长发育性疾病提供理论基础。