Osteocytes play an important role to modulate the bone remodeling and are also known as terminally differentiated cells originated from the osteoblast precursor cells, but its differentiation mechanism remains unclear. Since an efficient in vitro method to evoke the osteocyte differentiation from the osteoblast precursor cells has not been established, we conducted the comparative gene expression analysis for mouse pre-osteoblast MC3T3-E1 cells in order to elucidate the key factors to induce the osteocyte differentiation from the pre-osteoblast cells. In this study, we prepared four different culture environments by modulating their cell-substrate interaction and cell–cell interaction; (i) low and (ii) high cell density on the adhesive culture models, and (iii) low and (iv) high cell density on the non-adhesive floating culture models. By comparing these conditions in terms of cell-substrate and cell–cell interaction, we showed that the elimination of cell-substrate interaction under non-adhesive floating culture greatly up-regulated the gene expression of osteocyte markers in the pre-osteoblast cells. Moreover, the presence of moderate cell–cell interaction in the non-adhesive spheroid culture further enhanced the up-regulation of osteocyte markers for the pre-osteoblast cells. The results altogether suggest the most appropriate culture environment to induce the in vitro osteocyte differentiation of pre-osteoblast cells.

骨细胞在调节骨重塑中起重要作用，也称为起源于成骨细胞前体细胞的终末分化细胞，但其分化机制尚不清楚。由于一个有效的体外从成骨细胞前体细胞诱导骨细胞分化的方法尚未建立，我们对小鼠前成骨细胞 MC3T3-E1 细胞进行了比较基因表达分析，以阐明诱导前成骨细胞向骨细胞分化的关键因素. 在这项研究中，我们通过调节细胞-底物相互作用和细胞-细胞相互作用制备了四种不同的培养环境；(i) 粘附培养模型上的低和 (ii) 高细胞密度，以及 (iii) 非粘附性漂浮培养模型上的低和 (iv) 高细胞密度。通过在细胞-底物和细胞-细胞相互作用方面比较这些条件，我们表明，在非粘附性漂浮培养下消除细胞 - 底物相互作用大大上调了前成骨细胞中骨细胞标志物的基因表达。此外，在非粘性球体培养物中存在适度的细胞 - 细胞相互作用进一步增强了前成骨细胞的骨细胞标志物的上调。结果完全表明最合适的培养环境来诱导前成骨细胞的体外骨细胞分化。