槟榔碱激活非经典Wnt信号通路促进EndMT诱发口腔黏膜下纤维性变的研究

Oral submucous fibrous (OSF) is a chronic, occult oral potentially malignant disorder with genetic predisposition, and can be caused by chewing betel nut in which Acrecoline is the main substance. The mechanism of pathogenesis for OSF is still not well-understood, and thus far there have been no effective strategy for prevention and treatment.The endothelial-mesenchymal transition (EndMT) is known to be involved in the transformation of vascular endothelial cells to mesenchymal cells. EndMT has been shown to occur in various pathologic conditions. In the process of fibrosis, EndMT promotes myofibroblast activation and ECM deposition.We recently found that Wnt5a, a ligand for alternative Wnt pathways, was highly expressed in OSF tissue;Arecoline was found to promote Wnt5a expression in endothelial cells in vitro and impact on fate of endothelial cells. Therefore,we hypothesize that arecoline initiates EndMT by activating the alternative Wnt pathways in vascular endothelial cells, resulting in EndMT, which leads to submucous fibrous. In this proposal we will focus on the bridge molecule Gal12/13, which is both a central element in the alternative Wnt pathway and a downstream molecule in M receptor pathway that Arecoline binds. Using molecular and cellular techniques, the underlying mechanism of Arecoline mediated EndMT and OSF will be explored; the polymorphisms the gens involved in the process will be determined using Targeted Next Generation Sequencing to reveal the OSF genetic susceptibility. The success of this project will provide experimental basis for effective strategies in prevention and treatment of OSF.

口腔黏膜下纤维性变(OSF)是一种由于咀嚼槟榔引起的慢性、隐匿性的口腔潜在恶性疾病，具有遗传易感性，目前尚不明确其具体的发病机制，且无有效的防治方法。EndMT是内皮细胞向间质特性转化的细胞学过程，在纤维化过程中，其促进肌成纤维细胞激活和ECM沉积。我们近期发现非经典Wnt通路配体Wnt5a在OSF组织中高表达，体外槟榔碱促进内皮细胞Wnt5a表达并调节内皮细胞的转归，提示槟榔碱通过激活非经典Wnt通路启动血管内皮细胞EndMT，进而诱发口腔黏膜下纤维性变。本项目将研究槟榔碱通过非经典Wnt通路调控内皮细胞转归的作用，阐明槟榔碱激活非经典Wnt通路、非经典Wnt信号通路诱导血管内皮细胞EndMT的分子机制。最后利用靶向基因测序评价机制中特定基因的多态性与OSF遗传易感性之间的关系。从而为阐明槟榔碱诱发OSF的新的分子机制，寻求OSF新的分子靶点和有效的防治方案提供基础。

口腔黏膜下纤维性变(OSF)是一种由于咀嚼槟榔引起的慢性、隐匿性的口腔潜在恶性疾病，目前尚不明确其具体的发病机制，且无有效的防治方法。前期实验证明在OSF中存在微血管障碍，管周内皮细胞发生内皮间质转化（EndMT），可能是OSF发病的重要原因。本项目围绕OSF的发病机制进行了比较系统完整的研究，从其致病因子槟榔碱入手，关注微血管病变与OSF发病的关系，首次提出YAP在OSF的发生发展中起重要作用，槟榔碱刺激导致ROS的增加，进而激活内质网应激相关的PERK通路，导致YAP的活化。而YAP的活化同时又促进PERK通路的激活，形成增强YAP效应的正反馈机制，活化的YAP向细胞核内转移，与TEAD结合发挥转录因子的功能，诱导内皮间质转化（EndMT）相关基因表达，促进胶原分泌，导致ECM的积累。同时，成功构建了OSF的小鼠模型，使用维替泊芬（VP）进行干预，首次提出VP可以阻断槟榔碱诱发EndMT，可能作为治疗OSF的潜在靶向药物。研究成果为 OSF、器官组织纤维化的临床治疗寻找新的治疗途径和分子靶点提供理论依据。