Chen Sigeng, Ryan Daniel A, Dwyer Mary A, Cashman John R
The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
The Human BioMolecular Research Institute, San Diego, CA 92121, USA.
Bone. 2014 Oct;67:109-21. doi: 10.1016/j.bone.2014.06.032. Epub 2014 Jul 3.
Although osteoinductive ceramics can induce osteoblast differentiation in vitro and bone regeneration in vivo, their effects rely solely on the limited number of endogenous stem cells. More recently, ceramic carriers seeded with culture-expanded stem cells have been reported as implants capable of in vivo bone formation. However, effective and safe signaling agents that promote cell differentiation to the osteogenic lineage are still needed. In the present report, two osteogenic small-molecules THQ-1a and PP-9 were identified by testing a series of compounds for Runx2 and BMP2 expression in C2C12 cells. Compounds THQ-1a and PP-9 modulated Wnt signaling and enhanced the expression of molecular markers of osteoblast differentiation. To probe the utility of these compounds for use with ceramic cell implants, the effect of THQ-1a and PP-9 on C2C12 cell osteogenic differentiation was investigated in the presence of a tricalcium phosphate (TCP) ceramic. The effect of THQ-1a and PP-9 on markers such as Osteocalcin and Collagen I was significantly increased in the presence of TCP ceramic. Additionally, THQ-1a or PP-9 in the presence of TCP ceramic gave a synergistic increase in alkaline phosphatase activity in the differentiation of C2C12 cells. Taken together, the results suggest an approach to directing cell lineage commitment for bone regeneration by the application of small-molecule osteogenic agents to cells in the presence of osteoinductive ceramics.
尽管骨诱导陶瓷能在体外诱导成骨细胞分化并在体内促进骨再生，但其效果仅依赖于数量有限的内源性干细胞。最近，有报道称接种了经培养扩增的干细胞的陶瓷载体作为植入物能够在体内形成骨组织。然而，仍需要有效且安全的信号分子来促进细胞向成骨谱系分化。在本报告中，通过检测一系列化合物在C2C12细胞中对Runx2和BMP2表达的影响，鉴定出了两种成骨小分子THQ-1a和PP-9。化合物THQ-1a和PP-9调节Wnt信号通路并增强成骨细胞分化分子标志物的表达。为探究这些化合物与陶瓷细胞植入物联合使用的效用，在磷酸三钙（TCP）陶瓷存在的情况下，研究了THQ-1a和PP-9对C2C12细胞成骨分化的影响。在TCP陶瓷存在的情况下，THQ-1a和PP-9对骨钙素和I型胶原蛋白等标志物的影响显著增强。此外，在TCP陶瓷存在的情况下，THQ-1a或PP-9在C2C12细胞分化过程中使碱性磷酸酶活性协同增加。综上所述，这些结果提示了一种通过在骨诱导陶瓷存在的情况下将小分子成骨剂应用于细胞来指导细胞谱系定向分化以促进骨再生的方法。
