胰岛素样生长因子1（IGF-1）是牙齿发育过程中的关键分子，参与多种牙源性干细胞的分化调控，但其调控机制仍不清楚。本课题拟在前期IGF-1调控牙源性干细胞定向分化研究的基础上，围绕IGF-1/MAPK信号通路，系统地研究在IGF-1诱导的牙源性间充质干细胞分化过程中，hsa-let-7c对靶基因IGF-1R的转录后调控机制以及hsa-let-7c/IGF-1R调控轴对IGF-1/MAPK通路相关信号分子、下游转录因子（AP-1、RUNX2）、矿化相关因子、干细胞归巢和组织修复的分子调控作用，以期阐明hsa-let-7c/IGF-1R调控轴在IGF-1介导的牙源性间充质干细胞分化和再生过程中的作用机制。研究成果有助于揭示牙源性间充质干细胞的定向分化及“归巢”的分子调控机制，从而为牙源性干细胞功能改建、促进相关组织再生研究提供新思路，为IGF-1及牙源性干细胞介导的牙组织工程研究奠定理论基础。

Insulin-like growth factor 1 (IGF-1) is a key molecule in the tooth development and regulates the differentiation of several types of dental stem cells (DSCs). However, its modulation mechanism is still unclear. Based on our previous work in IGF-1 mediated differentiation of dental stem cells and the classical IGF-1/MAPK pathway, we will thoroughly investigate the effects of microRNA hsa-let-7c on its target gene IGF-1R, and evaluate the effects of hsa-let-7c/IGF-1R axis on IGF-1/MAPK pathway-related signals, downstream transcription factors (AP-1 and RUNX2), mineralization-related markers, stem cell homing capacity as well as tissue repair during IGF-1 mediated differentiation of dental mesenchymal stem cells in order to elucidate the modulation of hsa-let-7c/IGF-1R axis in the differentiation and regeneration of dental mesenchymal stem cells induced by IGF-1. These upcoming results will facilitate the understanding of the molecular mechanism during the committed differentiation and homing of dental mesenchymal stem cells, highlight a novel approach to the functional modification of dental stem cells and related tissue regeneration, and ultimately provide the theoretical evidence for IGF-1/DSCs mediated tooth engineering.