BMP-2 promotes differentiation of osteoblasts and chondroblasts in Runx2-deficient cell lines
BMP-2 promotes differentiation of osteoblasts and chondroblasts in Runx2-deficient cell lines
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DOI：
10.1002/jcp.20988
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发表时间：
2007-06-01
影响因子：
5.6
通讯作者：
Yamaguchi, Akira
中科院分区：
文献类型：
--
作者：
Liu, Tingjiao;Gao, Yuhao;Yamaguchi, Akira
为了探讨成骨细胞和成软骨细胞分化的分子机制，我们从Runx 2缺陷的小鼠胚胎中建立了克隆细胞系RD-C6。在基础培养条件下，RD-C6细胞几乎检测不到与成骨细胞和成软骨细胞分化相关的表型，而重组人骨形态发生蛋白-2（rhBMP-2）或腺病毒转导BMP-2可有效诱导该细胞系表达与成骨细胞和成软骨细胞分化相关的mRNA，包括碱性磷酸酶、骨钙素和osterix。Runx 2的转导也诱导这些mRNA在RD-C6细胞中的表达。BMP-2转导增加Msx 2和Dlx 5的mRNA表达水平，但Runx 2转导诱导这些mRNA的表达水平没有显著增加。使用RD-C6细胞与或不与rhBMP-2处理的微阵列分析表明，BMP-2上调66个基因，包括13个转录相关分子，如Id 1，Id 2，Id 4，Hey 1 Smad 6，Smad 7和Msx 2。为了证实RD-C6细胞的骨和软骨形成能力，我们使用含有rhBMP-2的扩散室将RD-C6细胞移植到无胸腺小鼠的腹腔中。RD-C6细胞产生未矿化的软骨，但不产生骨。这些结果表明，BMP-2诱导Runx 2缺陷细胞表达与成骨细胞和成软骨细胞分化相关的标记物，使用Runx 2非依赖性途径，但它未能诱导这些细胞分化成骨形成成骨细胞和成熟软骨细胞。
To investigate the molecular mechanism underlying the differentiation of osteoblasts and chondroblasts, we established a clonal cell lines, RD-C6, from Runx2-deficient mouse embryos. RD-C6 cells expressed almost undetectable levels of phenotypes related to osteoblast and chondroblast differentiation at basal culture condition, whereas treatment with recombinant human bone morphogenetic protein-2 (rhBMP-2) or transduction of BMP-2 by adenovirus effectively induced this cell line to express mRNA related to the differentiation of osteoblasts and chondroblasts including alkaline phosphatase, osteocalcin, and osterix. Transduction of Runx2 also induced the expression of these mRNA in RD-C6 cells. BMP-2 transduction increased expression levels of mRNA for Msx2 and Dlx5, but Runx2 transduction induced no significant increases in expression levels of these mRNA. Microarray analysis using RD-C6 cells with or without rhBMP-2 treatment demonstrated that BMP-2 upregulated 66 genes including 13 transcription-related molecules such as Id1, Id2, Id4, Hey1 Smad6, Smad7, and Msx2. To confirm bone and cartilage formation ability of RD-C6 cells, we transplanted RD-C6 cells into the peritoneal cavity of athymic mice using diffusion chambers with rhBMP-2. RD-C6 cells generated unmineralized cartilage but not bone. These results indicate that BMP-2 induces Runx2-deficient cells to express markers related to osteoblast and chondroblast differentiation using a Runx2-independent pathway, but it failed to induce these cells to differentiate into bone-forming osteoblasts and mature chondrocytes.