The expression of transcriptional factors and non-collagenous proteins in the differentiation of bone cells.

我们研究了原位定位成骨细胞/骨细胞因子45（OF 45）mRNA在骨形成过程中在发育大鼠下颌骨。在细胞培养过程中，不仅在原代大鼠成骨样细胞如分化的胎鼠颅骨细胞（FRCC）和原代大鼠骨髓基质细胞（SBMC）中，而且在存在或不存在有效的合成糖皮质激素地塞米松（Dex）或骨形态发生蛋白2（BMP-2）的情况下，在具有不同分化阶段的两种克隆大鼠成骨细胞系ROB-C26和ROS 17/2.8细胞中也是如此。这些实验结果得到以下结论。1.OF45 mRNA在成骨细胞中瞬时表达，在成骨细胞中表达，在成骨过程中，OF 45蛋白是成骨细胞的重要马克标志。 ...更多信息 r的骨细胞表型和最有可能参与调节骨细胞的功能。2. Dex对FRCC中Runx 2和Osterix mRNA的诱导可能随后激活成骨细胞标志物基因，如OC和BSP mRNA，以产生随后矿化的骨特异性基质。因此，Dex可能通过诱导Runx 2和Osterix基因的表达促进FRCC的成骨分化和矿化。3.与Dmp 1、OC、BSP和OPN相比，Dex对SBMC中OF 45基因表达的诱导作用更强。4. ROS 17/2.8细胞中转录因子（AJ18、Osterix和Dlx 5）和蛋白质（碱性磷酸酶、OC、BSP和OPN）的基因表达受Dex的控制，并且即使在存在或不存在Dex的情况下也与矿化相关地改变。5. ROB-C26细胞中AJ18和Runx 2 mRNA的表达受BMP-2和TGF-β1的调控，BMP-2和TGF-β1对AJ18 mRNA的表达有不同的影响，但在成骨细胞分化过程中均能有效刺激Runx 2 mRNA的表达。少

We examined in situ localization of osteoblast/osteocyte factor 45 (OF45) mRNA during bone formation in developing rat mandible. Gene expression of the transcription factors and oseoblast-related proteins such as OF45,dentin matrix protein 1(Dmp1), osteocalcin(OC), bone sialoprotein(BSP) and osteopontin(OPN) was also examined during cell culture not only in primary rat osteoblast-like cells such as differentiating fetal rat calvarial cells(FRCC) and primary rat stromal bone marrow cells(SBMC), but also in two clonal rat osteoblastic cell lines with different stages of differentiation, ROB-C26 and ROS 17/2.8 cells in the presence or absence of a potent, synthetic glucocorticoid dexamethasone(Dex) or bone morphogenetic protein 2(BMP-2). These experimental results obtained the following conclusions. 1.OF45 mRNA is transiently expressed by mature osteoblasts and subsequently expressed by osteocytes throughout ossification in the skeleton and this protein represents to be an important marke … More r of the osteocyte phenotype and most likely participates in regulating osteocyte function. 2.Induction of Runx2 and Osterix mRNAs in FRCC by Dex may be followed by activation of osteoblast marker genes such as OC and BSP mRNAs to produce a bone-specific matrix that subsequently becomes mineralized. Thus, it is likely that Dex may promote osteoblastic differentiation and mineralization of FRCC by inducing the expression of Runx2 and Osterix genes in vitro. 3.Gene expression of OF45 in SBMC is induced strongly by Dex when compared with that of Dmp1,OC, BSP and OPN. 4.The gene expression of the transcription factors (AJ18,Osterix and Dlx5) and the proteins (alkaline phosphatase, OC, BSP and OPN) in ROS 17/2.8 cells is under the control of Dex and is altered associated with mineralization even in the presence or absence of Dex. 5.The expression of AJ18 and Runx2 mRNAs in ROB-C26 cells is under the control of BMP-2 and TGF-β1, both of which exert different effects on AJ18 mRNA expression, but are potent stimulators of Runx2 mRNA expression during osteoblast differentiation. Less