干细胞可以通过旁分泌改变宿主微环境，促进组织的修复，但是其在牙髓-牙本质再生过程中所发挥的作用尚不清楚。本课题组前期工作发现人根尖牙乳头干细胞的分泌物明显促进牙髓细胞的迁移和成牙本质分化，可能调控牙髓-牙本质的再生。本项目拟从干细胞分泌的角度进行牙髓-牙本质再生的机理研究。探讨参与牙髓-牙本质发育的关键干细胞-人根尖牙乳头干细胞的分泌蛋白质组学，比较其与人骨髓间充质干细胞分泌蛋白的差异。通过对差异蛋白的生物学分析，得到两种不同组织来源干细胞分泌物的成血管功能、神经营养功能、免疫调节功能、趋化功能、牙本质形成功能及抗细胞凋亡功能的参数，为进一步临床扩展应用提供参考。接着，进行人根尖牙乳头干细胞旁分泌在牙髓-牙本质再生中作用的功能性研究，即分泌物对牙髓细胞生物学特性的体外影响及对牙髓-牙本质再生的体内影响，为将来干细胞分泌物的临床应用提供实验依据。

The paracrine effects of growth factors and cytokines secreted from the implanted mesenchymal stem cells (MSCs) may change the microenvironment of the host and promote tissue repairs; however, the paracrine effects of MSCs involved in dentin-pulp regeneration are not clear. Our previous study has proved that the secretome of human dental apical papilla-derived stem cells (hSCAP) significantly enhances mobilization and odontogenic differentiation of human dental pulp cells (hDPC), suggesting that the paracrine effects of hSCAP may promote the tissue repair of dentin-pulp. .In this study, we attempt to elucidate the molecular mechanisms involved in dentin-pulp regeneration from the perspective of secretome. Firstly, we investigated the secretome of human SCAPs using LC-MS/MS analysis and compared the resulting profile to that of BMSCs; with the aim of achieving insights into the functional role of SCAPs secretions and the molecular basis of their actions. Secondly, we plan to evaluate the effects of hSCAP-secretome on hDPC in vitro, and investigate the effects of hSCAP-secretome on dentin-pulp regeneration in vivo.

本研究探索人根尖牙乳头干细胞的分泌蛋白质组学，分析其对牙髓再生的的影响。从人根尖牙乳头干细胞的条件培养液中检测到2046种蛋白，包括分泌参与血管生成、免疫调节、抗细胞凋亡、趋化和神经营养的蛋白。与人骨髓间充质干细胞相比，人根尖牙乳头干细胞分泌的神经因子、趋化因子和参与细胞代谢的蛋白更多，而分泌的胞外基质蛋白更少。在体外，人根尖牙乳头干细胞条件培养液对牙髓细胞增殖无明显影响；促进成牙本质分化，效果强于人骨髓间充质干细胞；促进牙髓细胞的迁移。在体内，人根尖牙乳头干细胞条件培养液促进根管内血管和成牙本质细胞的形成。人根尖牙乳头干细胞分泌多种细胞因子和生长因子，其分泌功能在牙髓-牙本质形成过程中发挥重要作用。其中一部分成果发表在《Stem Cells and Development》杂志，培养了四名博士研究生和三名青年研究骨干。