Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
Dental Stem Cell Biology Research Unit, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand.
Sci Rep. 2022 Nov 8;12(1):19021. doi: 10.1038/s41598-022-21479-8.
The self-organizing potential of induced pluripotent stem cells (iPSCs) represents a promising tool for bone tissue engineering. Shear stress promotes the osteogenic differentiation of mesenchymal stem cells, leading us to hypothesize that specific shear stress could enhance the osteogenic differentiation of iPSCs. For osteogenesis, embryoid bodies were formed for two days and then maintained in medium supplemented with retinoic acid for three days, followed by adherent culture in osteogenic induction medium for one day. The cells were then subjected to shear loading (0.15, 0.5, or 1.5 Pa) for two days. Among different magnitudes tested, 0.5 Pa induced the highest levels of osteogenic gene expression and greatest mineral deposition, corresponding to upregulated connexin 43 (Cx43) and phosphorylated Erk1/2 expression. Erk1/2 inhibition during shear loading resulted in decreased osteogenic gene expression and the suppression of mineral deposition. These results suggest that shear stress (0.5 Pa) enhances the osteogenic differentiation of iPSCs, partly through Cx43 and Erk1/2 signaling. Our findings shed light on the application of shear-stress technology to improve iPSC-based tissue-engineered bone for regenerative bone therapy.
诱导多能干细胞（iPSCs）的自组织潜能代表了一种很有前途的骨组织工程工具。切应力促进间充质干细胞的成骨分化，这使我们假设特定的切应力可以增强 iPSCs 的成骨分化。为了成骨，先将类胚体形成两天，然后在补充维甲酸的培养基中维持三天，然后在成骨诱导培养基中进行贴壁培养一天。然后，将细胞在 0.15、0.5 或 1.5 Pa 的切应力下处理两天。在所测试的不同幅度中，0.5 Pa 诱导最高水平的成骨基因表达和最大的矿化沉积，对应于连接蛋白 43（Cx43）和磷酸化 Erk1/2 表达的上调。在切应力加载过程中抑制 Erk1/2 会导致成骨基因表达降低和矿化沉积受到抑制。这些结果表明，切应力（0.5 Pa）增强了 iPSCs 的成骨分化，部分是通过 Cx43 和 Erk1/2 信号传导。我们的发现为应用切应力技术来改善基于 iPSC 的组织工程骨以进行再生骨治疗提供了思路。
