成骨区血管化难是限制组织工程骨用于修复颅颌面骨缺损的关键。我们前期发现成骨成血管双向诱导分化的脂肪间质干细胞(ASCs)共培养后成骨成血管能力显著提高，且SDF-1/CXCR-4在其中起关键作用。高通量测序检测发现双向诱导分化ASCs共培养后Rap1等多个通路被激活。这些被激活的通路大部分受Rap1通路调控。进一步的阻断实验发现SDF-1/CXCR-4与Rap1通路密切相关。基于此，我们提出以下科学假说：双向诱导分化ASCs共培养后成骨成血管能力增强可能由SDF-1/CXCR-4激活Rap1通路进行调控。故本项目拟通过多节点正反向干扰实验体外验证该假说，明确Rap1作用亚型及激活路径，并利用过表达及抑制Rap1作用亚型和激活酶的共培养体系，体内探究SDF-1/CXCR-4介导Rap1通路调控血管化骨组织重建的机制，明确关键靶点，为优化ASCs共培养体系，提高颅颌面骨缺损修复效果提供新思路。

The difficulty of vascularization in osteogenic region is the key to limit the use of tissue engineered bone in repairing cranio-maxillofacial defects. Adipose-derived stem cells (ASCs) are relatively readily available from adipose tissues, which have shown great promise for osteogeneration and vascularization. In our recent studies, we found that co-cultured ASCs showed increased osteogenic and angiogenic differentiation, owing to the regulation of SDF-1/CXCR-4. RNA sequencing (RNA-seq) showed that multiple pathways such as Rap1 pathway were activated after co-culture. It’s worth noting that most of these activated pathways are regulated by the Rap1 pathway. Further blocking experiments showed that SDF-1/CXCR-4 axis was closely related to Rap1 pathway. Based on these, we propose the following hypotheses: the enhancement of osteogeneration and vascularization of co-cultured ASCs may be regulated by the SDF-1/CXCR-4 mediated Rap1 pathway. Therefore, this project is to verify the hypothesis in vitro through multiple nodes interference clarifying the functional Rap1 subtypes and activation pathway, and further utilize ASCs co-culture system which are overexpressing and inhibiting functional Rap1 subtype and activase to explore the mechanism of SDF-1/CXCR-4 mediated Rap1 pathway in the regulation of vascularized bone reconstruction in vivo, hoping to identify the key target point for optimizing ASCs co-culture system and finally improve the effect of cranio-maxillofacial bone reconstruction.