LncRNA DANCR调控miR-216a/c-Cbl轴在牙髓防御修复中的作用研究

促进牙髓细胞（DPCs）成牙本质向分化是牙髓牙本质复合体再生的关键。本人已发表论文与预实验结果发现：在DPCs成牙本质向分化及牙髓组织修复性反应中，lncRNA DANCR表达下调，如高表达，则可阻遏Wnt/β-catenin通路抑制DPCs分化；DANCR与miR-216a结合，且在分化过程中呈负相关，而miR-216a靶向沉默c-Cbl，后者抑制Wnt通路。因此我们提出：DANCR可竞争性结合miR-216a，解除对c-Cbl的靶向沉默，进而抑制Wnt通路调控DPCs成牙本质向分化。本项目拟进一步运用RIP、报告基因等技术分析DANCR/miR-216a/c-Cbl的相互关系，探讨这种竞争调控模式对下游Wnt通路及DPCs成牙本质向分化的生物学效应；采用裸鼠皮下移植实验，阐明敲低DANCR对DPCs成牙本质向分化及牙髓牙本质复合体形成的促进作用，为牙髓防御修复研究及转化应用提供新思路。

Enhanced odontoblast differentiation of human dental pulp cells (DPCs) is considered a keystone in dentin-pulp complex formation. In our published paper and preliminary studies, we identified lncRNA DANCR was downregulated during the differentiation process of DPCs and the reparative response of dental pulp, while overexpression of DANCR suppressed odontoblast differentiation of DPCs by inhibiting Wnt/β-catenin signaling. Notably, we further provided evidence that DANCR could competitively bind to miR-216a and there was a negative correlation between DANCR and miR-216a expression during the differentiation process. Moreover, recent studies reported that c-Cbl, the target gene of miR-216a, inactivated Wnt signaling pathway. Therefore, we hypothesized that DANCR may act as a competing endogenous RNA to bind miR-216a, then stabilize c-Cbl protein translation, thereby inhibiting Wnt signaling pathway and odontoblast differentiation. In this grant, we will utilize RIP and luciferase reporter to explore the relationship among DANCR/miR-216a/c-Cbl, and clarify the significance of this event in regulation of Wnt signaling and the odontoblast differentiation of DPCs. Moreover, the effect of DANCR downexpression in DPCs differentiation and dental pulp-dentin complex formation will be accessed through in vivo experiment, which will be conducted by transplanting root segments subcutaneously into immune deficiency mice. Our results will provide new ideas for further study and clinical translation of the reparative response of dental pulp.