血管和神经化促进组织工程骨形成的机制研究

Vascularization and innervation play important roles in the development and function of bone tissues. The synergies of blood vessels and nerves are certainly required for the reconstruction of tissue engineering bone, which will be applied for the repair of segmental bone defects. However there is still lack of a perfect method for the development of vascularized and neuralized tissue engineered bone. Furthermore, the related mechanism is also unclear. In the previous studies, we are the first group in the world to construct vascularized tissue engineered bone in large animals and primates in vivo successfully. Meanwhile, we are the first group in the world to demonstrate that the implantation of vascular bundles and sensory nerve shared similar effect in promoting the innervation of tissue engineered bone as well as bone regeneration. The signaling pathways of OPG/RANK/RANKL were found to have some regulating effects on the above phenomena. To reveal the underlying mechanism the following research will be carried out in this project. (1) Dynamic observation of single or synergy effects of vascularization and innervation on the formation caused by tissue engineered bone. (2) The relationship between key molecules in the OPG/RANK/RANKL pathway and formation as well as mineralization of bone tissues after vascularization and innervation. (3) The observation of osteogenic effect of vascularized and neuralized tissue engineered bone by blocking or upward the expression of key factors in the OPG/RANK/RANKL pathway. The implementation of this project will provide important theoretical basis for the reconstruction of contribute to tissue engineered bone and other tissue engineered tissues or organs.

血管、神经在组织器官发育、生长和修复等生物学过程发挥重要的支配与调节作用。在构建用于大段骨缺损修复的组织工程骨过程中无疑需要血管、神经产生协同效应。然而血管、神经化促进组织工程骨发挥成骨作用的机制尚不明确。在前期工作中，本课题组率先在大动物及灵长动物体内成功构建血管化组织工程骨，同时首次证实血管束植入与感觉神经植入具有同等的神经化作用和相似的促成骨效果。相关结果提示血管和神经化的促成骨作用可能与OPG/RANK/RANKL信号通路的调控有关。为此，本项目拟深层次开展相关研究:（1）血管、神经化对组织工程骨成骨单一和协同作用的动态观察：（2）血管、神经化后OPG/RANK/RANKL通路相关分子的表达水平变化与骨形成和矿化的关系；（3）通过阻断和上调通路的相关因子表达，观察血管、神经化后组织工程骨成骨效果的变化。本课题的实施将可为组织工程骨以及其他组织工程化组织、器官的构建提供重要理论依据。

血管和神经在机体组织和器官的发育、代谢、修复过程中发挥着难以替代的支配和调节作用。课题组前期研究证实血管束植入与感觉神经植入具有同等的神经化作用和相似的促成骨效果。本课题深入研究血管神经化的协同作用及机制，为实现组织工程骨血管和神经同步构建提供重要的立论依据和实验基础。在课题实施过程中，以标书内容为指导，不断引进新技术，完善课题设计（调整了上述实施计划6-9条的研究内容），首次证实血管化改善缺损部位微环境，阐明其调控种子细胞命运转归的作用机制；发现了一种新的感觉神经肽Cyp40，揭示了感觉神经对破骨细胞的直接调控作用；验证血管神经联合移植对组织工程骨形成具有协同促进作用。