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

我们研究了成骨细胞/骨细胞因子45(OF 45)在大鼠下颌骨发育过程中的原位定位。在细胞培养过程中，我们还检测了转录因子和成骨细胞相关蛋白Of 45、牙本质基质蛋白1(Dmp1)、骨钙素(OC)、骨涎蛋白(BSP)和骨桥蛋白(OPN)的基因表达，不仅在原代大鼠成骨样细胞(如分化中的胎鼠颅骨细胞(FRCC)和原代大鼠基质骨髓细胞(SBMC))中，而且在两种不同分化阶段的克隆性大鼠成骨细胞系Rob-C26和Ros 17/2.8细胞中，有或没有强大的糖皮质激素地塞米松(Dex)或骨形态发生蛋白2(BMP-2)。这些实验结果得出了以下结论。1.of45mrna由成熟的成骨细胞瞬时表达，随后在骨骼的成骨过程中由骨细胞表达，该蛋白是一种重要的标记…。更多的骨细胞表型，很可能参与了骨细胞功能的调节。2.地塞米松诱导FRCC中的Runx2和Osterix mRNAs后，可能会激活成骨细胞标志基因，如OC和BSP mRNAs，以产生骨特异性基质，该基质随后变为矿化。因此，地塞米松在体外可能通过诱导Runx2和Osterix基因的表达来促进肾细胞癌的成骨分化和矿化。3.与Dmp1、OC、BSP和OPN相比，Dex对SBMC中of45基因的表达有较强的诱导作用。4.在ROS 17/2.8细胞中，转录因子(AJ18、Osterix和Dlx5)和蛋白(碱性磷酸酶、OC、BSP和OPN)的基因表达受Dex的调控，并与矿化有关，即使在有或没有Dex的情况下也是如此。5.AJ18和Runx2mRNAs在ROB-C26细胞中的表达受骨形态发生蛋白-2和转化生长因子-β1的调控，二者对AJ18mRNAs的表达有不同的影响，但在成骨细胞分化过程中对Runx2mRNAs的表达有很强的刺激作用。较少

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