外泌体是细胞主动释放介导细胞间物质与信息传递的囊泡状小体。申请者在上一个面上项目的支持下，发现炎性刺激下成牙本质细胞除了利用细胞内自噬机制参与损伤修复之外，还可增加外泌体释放。因此提出科学假说：“炎性成牙本质细胞来源的外泌体介导的细胞间信号传导在成牙本质细胞炎性损伤修复中发挥作用。” 本项目拟从以下方面开展工作：(1)明确炎性微环境中成牙本质细胞外泌体的分泌模式；(2) 利用共培养模型及外泌体示踪技术明确外泌体在炎性成牙本质细胞损伤修复中的作用；(3)利用中通量芯片筛选，生物信息学分析结合生物学验证，明确炎性微环境下成牙本质细胞源性外泌体中主要与成牙本质细胞生存及牙髓间充质干细胞成牙本质向分化相关的蛋白及miRNA；(4) 构建成牙本质细胞特异性外泌体分泌缺陷小鼠，探讨外泌体调控成牙本质细胞炎性损伤修复的体内机制。本项目的开展将进一步加深对炎性微环境中成牙本质细胞损伤修复分子机制的理解。

Exosome is a kind of extracellular microvesicles, which plays an important role in intercellular communication. Our primary study had demonstrated that the inflamed odontoblasts not only take advantage of autophagic flux, but also increase the numbers of exosomes under the inflammatory stimulation. We proposed the hypothesis that the inflamed-odontoblast-derived exosomes (IOD-Exo) might participate in the survival of the injured odontoblasts and odontogenic differentiation of the dental pulp mesenchymal stem cells（DPMSC）. This project includes four parts. Firstly, we will detect and quantify exosomes from human caries and pulpitis samples compared with the counterparts. Secondly, we will establish in vitro co-culture system to confirm the biological role of IOD-Exo in the survival of odontoblasts and differentiation of DPMSC. The secretion and uptake of IOD-Exo will be tracing by time-lapse confocal microscope. Thirdly, we will identify the major enriched miRNA and protein of IOD-Exo which related to cell survival of odontoblasts and differentiation of DPMSC. MiRNA microarray and antibody array will be used following biological validation. Finally, we will investigate the role of IOD-Exo in the survival of injured odontoblast and odontogenic differentiation of DPMSC in vivo. Rab11a odontoblast conditional knock-out mice and experimental dental pulp injury model will be generated. In summary, the accomplishment of this project might help to elucidate the role of intercellular communication conducted by exosomes in inflamed odontoblast reparation.