An osteogenesis-related transcription factor, core-binding factor A1, is constitutively expressed in the chondrocytic cell line TC6, and its expression is upregulated by bone morphogenetic protein-2
An osteogenesis-related transcription factor, core-binding factor A1, is constitutively expressed in the chondrocytic cell line TC6, and its expression is upregulated by bone morphogenetic protein-2
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DOI：
10.1677/joe.0.1650579
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发表时间：
2000-06-01
影响因子：
4
通讯作者：
Noda, M
中科院分区：
文献类型：
--
作者：
Takazawa, Y;Tsuji, K;Noda, M
核心结合因子Al (Cbfa1)，又称Pebp2 α A/AML3，是一种属于矮子结构域基因家族的转录因子。缺乏Cbfa1的小鼠完全不能形成软骨内和膜内的骨，这表明Cbfa1对于成骨是必不可少的，这些小鼠的软骨细胞成熟也紊乱，提示Cbfa1也可能在软骨形成中发挥作用。本研究的目的是检测Pebp2 α A/AML3/Cbfa1在软骨细胞样细胞系TC6中的表达和调控，Northern blot分析表明，Cbfa1 mRNA在TC6细胞中以6.3 kb的信息组成性表达，并且骨形态发生蛋白2 （bone morphogenetic protein-2, BMP2）处理后Cbfa1的表达水平呈时间和剂量依赖性增强。这种作用被RNA聚合酶抑制剂5,6-二氯-1- β -d -核糖呋喃基苯并咪唑阻断，但不被蛋白质合成抑制剂环己亚胺阻断。用Cbfa1多克隆抗体对细胞裂解物进行Western blot分析表明，BMP2处理增加了TC6细胞中Cbfa1蛋白的水平。在TC6细胞中，BMP2处理增强了碱性磷酸酶和I型胶原mRNA的表达，抑制了II型胶原mRNA的表达。除了TC6细胞外，Cbfa1 mRNA也在软骨细胞原代培养物中表达，BMP2处理增强了这些细胞中Cbfa1 mRNA的表达，类似于其对TC6细胞的作用。这些数据表明Pebp2 α A/AML3/Cbfa1基因在软骨细胞样细胞系TC6中表达，并且其表达通过BMP处理而增强。
Core-binding factor Al (Cbfa1), also called Pebp2 alpha A/AML3, is a transcription factor that belongs to the runt-domain gene family. Cbfa1-deficient mice are completely incapable of both endochondral and intramembranous bone formation, indicating that Cbfa1 is indispensable for osteogenesis, Maturation of chondrocytes in these mice is also disorganized, suggesting that Cbfa1 may also play a role in chondrogenesis. The aim of this study was to examine the expression and regulation of Pebp2 alpha A/AML3/Cbfa1 expression in the chondrocyte-like cell line, TC6, Northern blot analysis indicated that Cbfa1 mRNA was constitutively expressed as a 6.3 kb message in TC6 cells and the level of Cbfa1 expression was enhanced by treatment with bone morphogenetic protein-2 (BMP2) in a time- and dose-dependent manner. This effect was blocked by an RNA polymerase inhibitor, 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, but not by a protein synthesis inhibitor, cycloheximide. Western blot analysis of the cell lysates using polyclonal antibody raised against Cbfa1 indicated that BMP2 treatment increased the Cbfa1 protein level in TC6 cells. In TC6 cells, BMP2 treatment enhanced expression of alkaline phosphatase and type I collagen mRNAs but suppressed that of type II collagen mRNA. In addition to TC6 cells, Cbfa1 mRNA was also expressed in primary cultures of chondrocytes and BMP2 treatment enhanced Cbfa1 mRNA expression in these cells similarly to its effect on TC6 cells. These data indicate that the Pebp2 alpha A/AML3/Cbfa1 gene is expressed in a chondrocyte-like cell line, TC6, and its expression is enhanced by treatment with BMP.