间充质干细胞（MSCs）具有较强的成骨分化潜能，已成为骨组织工程中最为广泛应用的种子细胞。探讨MSCs成骨分化机制可进一步促进其在骨组织工程中的应用。我们前期研究发现在人骨髓间充质干细胞（hMSCs）中AC132217.4和IGF2表达丰度随着分化程度的增加而增加。AC132217.4干扰和过表达分别抑制和促进了hMSCs的成骨分化和IGF2的表达，表明AC132217.4/IGF2可能参与了hMSCs成骨分化的调节。由此，本课题拟通过研究AC132217.4对hMSCs成骨分化细胞中mRNA, miR的影响，明确AC132217.4对成骨分化的作用机制；同时，通过RNA-pull down，并结合质谱和基因调控等技术，阐明成骨分化过程中调控AC132217.4表达和剪接的上游机制。本项目研究将有助于深入认识hMSCs成骨分化的分子机制，为骨修复与骨组织工程研究提供新的科学理论依据。

Mesenchymal stem cells (MSC) have become the most widely used seed cells for bone tissue engineering as their easy to take, strong self-renewal ability and osteogenic differentiation potential. The study of osteogenic differentiation mechanism of MSCcan further promote its application in bone tissue engineering. Our previous study found that the expression abundance of AC132217.4 and IGF2 in human bone marrow mesenchymal stem cells (hMSCs) increased with the increased osteogenicdifferentiation time. And the interference and overexpression of AC132217.4 inhibited and promoted osteogenic differentiation and IGF2 expression of hMSCs, respectively. It is suggested that AC132217.4may regulate osteogenic differentiation of hMSCs through AC132217.4/ IGF2 singling. On this basis, this study intends to study the effect of AC132217.4 regulation on the mRNA and miRexpression duringhMSCsosteogenic differentiation, and then clarify the mechanism of action of AC132217.4 on osteogenic differentiation. At the same time, we try to elucidate the upstream regulation mechanism of AC132217.4 expression and splicing during osteogenicdifferentiatiothroughby using RNA-pull down, mass spectrometry and gene regulationtechnology. The implementation of this project will gain a deeper understanding of osteogenic differentiation of hMSCs, thereby promoting its application in bone tissue engineering.