骨形态发生蛋白1A型受体介导的信号通路在成骨细胞终末分化中的调节作用  

Bone morphogenetic protein receptor 1A-mediated signaling pathway regulates osteoblast terminal differentiation in vivo

作　　者：李昂[1] 鲍全伟 陈思旭[1] 刘华渝[1] 李俊峰[1] 陈辉[1] 钟孝政[1] 宗兆文[1] 

机构地区：[1]第三军医大学大坪医院野战外科研究所创伤实验室,创伤,烧伤与复合伤国家重点实验室,重庆400042

出　　处：《第三军医大学学报》2016年第15期1717-1721,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金(81271935);创伤;烧伤与复合伤国家重点实验室自主课题(SKLZZ201124);"十二五"科研项目重大项目分课题(AWS11J008)~~

摘　　要：目的观察骨形态发生蛋白1A型受体(bone morphogenetic protein receptor 1A,BMPR1A)介导的信号通路在成骨细胞终末分化中的调节作用。方法使用Lox P/Cre系统,以3.2 kbⅠ型胶原蛋白为启动子,在小鼠成骨细胞中特异性敲除BMPR1A(不含Cre的小鼠记为对照组),采用Von Kossa染色、细胞茜素红染色,扫描电镜观察成骨细胞矿化能力的改变;MASSON染色、天狼星红染色观察成骨细胞胶原合成能力的变化;免疫组化染色、细胞周期检测初步探讨其成骨细胞终末分化阻滞的可能机制。结果 BMPR1A敲除小鼠与对照组小鼠相比:1矿化能力明显下降,且细胞间连接减少,间隙变大;2胶原合成能力减弱,胶原排列不规则;3FGF23与OPN的表达升高,细胞周期的阻滞是成骨细胞终末分化障碍可能的原因。结论 BMPR1A在成骨细胞终末分化中起着至关重要的作用,敲除后可导致小鼠骨矿化减弱,胶原合成能力下降。Objective To investigate the role of bone morphogenetic protein receptor 1A（BMPR1A）- mediated signaling in osteoblast terminal differentiation in vivo. Methods LoxP/Cre system was used to conditionally knock out BMPR1A in osteoblast by cross-breeding Cre mice （3.2 kb collagen I as promoter） with BMPR1A LoxP ＋/＋ mice. Their offsprings lacking active Cre was grouped into control. Von Kossa staining, Alizarin red staining and scanning electron microscopy were carried out to observe the mineralization of osteoblast. Masson staining and sirius red staining were used for evaluation of collagen synthesis ability in osteoblast. Immunohistochemistry staining and cell cycle analysis were employed to mechanistically study terminal differentiation of osteoblast. Results Compared with control group,we found that BMPR1A knockout mice had attenuated bone mineralization associated with decreased intercellular connection and enlarged intercellular gap. Masson staining showed reduced collagen synthesis with irregular collagenic arrangement. In addition, fibroblast growth factor 23 （FGF23） and osteopontin （OPN） were upregulated. Cell cycle analysis found that a large number of osteoblast arrested at G phrase of cell cycle, which partly impeded the terminal differentiation of osteoblast. Conclusion BMPR1A plays an important role in osteoblast terminal differentiation. Knocking out BMPR1A leads to decreased bone mineralization and collagen synthesis.

关 键 词：骨形态发生蛋白1A型受体 成骨细胞 终末分化 矿化 

分 类 号：R322.71[医药卫生—人体解剖和组织胚胎学] R329.24[医药卫生—基础医学]