Calcium phosphate (BCP) ceramic is a promising material in bone regeneration because it was proved biocompatible, osteoconductive, osteoinductive, and effective. Although it manifests favorable characteristics in critical‐sized bone defects repair, the mechanism of its osteoinduction is still unclear. In the present study, we studied the mechanism of ectopic bone formation, with interest in the Notch signaling pathway. BCP ceramics with or without Notch signaling inhibitor RO4929097 were cocultured with bone marrow‐derived stem cells in vitro. The expression of osteogenesis (OPN/Col/Runx2) and Notch signaling pathway‐related genes (Hes1/Jagged/Notch1) were increased in the BCP group compared with the control group without BCP but significantly decreased after adding RO4929097. Furthermore, a higher level of alkaline phosphatase activity was observed in the BCP group compared with RO4929097 and control group separately. For further confirmation, the intramuscularly ectopic implantation models of Beagle dogs were used. Quantitative real‐time polymerase chain reaction showed a similar trend with the in vitro experiment. Histological and histomorphometric analysis indicated that bone formation was delayed by RO4929097. These findings illustrated that the Notch signaling pathway plays a pivotal role in bone formation induced by BCP; Notch signaling pathway may positively influence ectopic bone formation by promoting BMSCs to differentiate toward osteoblasts.

中文翻译：

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缺口信号通路在双相磷酸钙陶瓷诱导的异位骨形成中的意义：初步实验。

磷酸钙 (BCP) 陶瓷是一种很有前途的骨再生材料，因为它被证明具有生物相容性、骨传导性、骨诱导性和有效性。尽管它在临界尺寸的骨缺损修复中表现出良好的特性，但其成骨机制仍不清楚。在本研究中，我们研究了异位骨形成的机制，并对 Notch 信号通路感兴趣。在体外将含有或不含 Notch 信号抑制剂 RO4929097 的 BCP 陶瓷与骨髓干细胞共培养。与没有BCP的对照组相比，BCP组成骨（OPN/Col/Runx2）和Notch信号通路相关基因（Hes1/Jagged/Notch1）的表达增加，但加入RO4929097后显着降低。此外，分别与 RO4929097 和对照组相比，在 BCP 组中观察到更高水平的碱性磷酸酶活性。为了进一步确认，使用了比格犬的肌内异位植入模型。定量实时聚合酶链反应显示出与体外实验相似的趋势。组织学和组织形态计量学分析表明 RO4929097 延迟了骨形成。这些发现说明 Notch 信号通路在 BCP 诱导的骨形成中起关键作用；Notch 信号通路可能通过促进 BMSCs 向成骨细胞分化来积极影响异位骨形成。定量实时聚合酶链反应显示出与体外实验相似的趋势。组织学和组织形态计量学分析表明 RO4929097 延迟了骨形成。这些发现说明 Notch 信号通路在 BCP 诱导的骨形成中起关键作用；Notch 信号通路可能通过促进 BMSCs 向成骨细胞分化来积极影响异位骨形成。定量实时聚合酶链反应显示出与体外实验相似的趋势。组织学和组织形态计量学分析表明 RO4929097 延迟了骨形成。这些发现说明 Notch 信号通路在 BCP 诱导的骨形成中起关键作用；Notch 信号通路可能通过促进 BMSCs 向成骨细胞分化来积极影响异位骨形成。