SHED聚合体外泌体转运miR-26a介导相关级联通路诱导血管形成参与全牙髓再生的作用机制研究

课题组首次建立基于乳牙牙髓干细胞聚合体（SA）移植的年轻恒牙全牙髓再生方法，成果发表于Science Translational Medicine，但发现对于成熟恒牙的疗效不甚理想。前期发现SA分泌的外泌体（SA-exosomes）可以显著提升牙髓再生的效能和血管形成量，而其中的miR-26a含量明显增高。基于以往研究基础，我们推测外泌体转运miR-26a介导PTEN/PI3K/AKT级联通路诱导血管形成促进全牙髓再生，但其具体机制尚不清楚。故本项目拟采用外泌体示踪、MicroRNA调控等方法，建立成熟恒牙全牙髓再生模型，观察SA-exosomes的作用模式，检测miR-26a对血管形成的影响，分析miR-26a调控植体细胞分化的分子机制，评估优化聚合体用于牙髓再生的功效，以期阐明SA-exosomes转运miR-26a促进血管形成的作用机理，建立更高效的成熟恒牙全牙髓再生治疗方法。

We have previously established a method of regenerating full-length dental pulp based on SHED aggregate (SA), and have successfully carried out clinical trial in the patients with pulp necrosis of immature incisors after traumatic dental injuries. Some of the results were newly published in Science Translational Medicine. However, previous studies found that the above methods are not ideal for mature teeth. Our study found that SA-exosomes could play a major role in the angiogenesis during full-length dental pulp regeneration, in which mir-26a has risen observably. Base on the previous researches, we infer that exosomes could transfer mir-26a to mediate the PTEN/PI3K/AKT cascade effect on the angiogenesis during full-length dental pulp regeneration, but the specific regulation mechanism is still not clear. So in this study, we want to firstly established the model of full-length dental pulp regeneration in mature teeth based on SA transplantation, and secondly to observe the endocytosis patterning of SA-exosomes in implant cell using the specific tracer technique, and then to test the effect of miR-26a on angiogenesis using MicroRNA intervention methods, and further to analyze the regulation mechanism of miR-26a-mediated cascades, finally to evaluate the regeneration efficiency of modified SA transplantation. We wish to elucidate the regulation mechanism that exosomes transfer mir-26a to mediate the related cascade effect on the angiogenesis during full-length dental pulp regeneration, and to establish the more efficient method of full-length dental pulp regeneration for the endodontic diseases of mature teeth.