TGF-β1/miR-29b信号轴通过内皮微粒调控静脉畸形非稳态血管形成的研究

Venous malformation (VM) is a common congenital disease associated with vascular development disorders which frequently involves skin and mucosa, and formation of disorganized vascular structures is considered as a pivotal pathological basis of VM. Our research group have previously validated that formation of disorganized vascular structures in VM is closely associated with down-regulation of TGF-β1 in endothelial cells (ECs), but its precise underlying mechanisms remain largely unclear. Moreover, our preliminary data have implicated that there is TGF-β1/miR-29b signaling axis in ECs of VM, which may result in up-regulation of miR-29b; endothelial microparticles (EMPs) can convey miR-29b to perivascular smooth muscle cells, thereby modulating the formation of disorganized vascular structures. Therefore, we hypothesize that TGF-β1/miR-29b signaling axis may regulate formation of disorganized vascular structures in VM via EMPs. To test this hypothesis, the present project is aimed to explore the role of TGF-β1/miR-29b signaling axis in regulating disorganized vascular structures of VM via EMPs and its precise underlying mechanisms, which is realized by multiple level investigation (tissues, cells and microparticles) and various techniques including in situ hybridization, cell co-culture and flow cytometry. Our project may further clarify the pathogenesis of VM, and would provide novel insights into VM treatment.

静脉畸形是一种常累及皮肤和粘膜的血管发育异常性疾病，非稳态血管形成是静脉畸形发生发展的重要病理基础。本课题组前期研究证实，静脉畸形非稳态血管形成与内皮细胞TGF-β1表达下调密切相关，但TGF-β1对非稳态血管形成的调控机制目前尚不明确。本研究前期结果还提示：静脉畸形内皮细胞中存在TGF-β1/miR-29b负向调控信号轴，导致miR-29b表达上升；miR-29b可进一步通过内皮微粒传递至管周平滑肌细胞，调控非稳态血管相关因素。因此我们假设：TGF-β1/miR-29b信号轴可通过内皮微粒调控静脉畸形非稳态血管形成。为验证这一推测，本项目拟从组织-细胞-微粒三个层次，借助原位杂交、细胞共培养和流式细胞术等技术，探究TGF-β1/miR-29b信号轴通过内皮微粒对静脉畸形非稳态血管形成的调控作用及其具体机制。本研究可进一步揭示静脉畸形的发病机制，并为静脉畸形的治疗提供新的思路。

静脉畸形是一种常见的先天性血管发育异常性疾病，其病变随年龄增长逐渐增大，可引起患者容貌畸形和功能障碍，严重时危及患者生命。近年来研究表明内皮细胞生物学异常是静脉畸形发生发展的重要原因，然而其具体机制尚不明确。本项目重点关注静脉畸形发病的重要病理基础——“非稳态血管形成”，围绕内皮细胞TGF-β通路、非稳态血管形成关键因素“细胞外基质”的生物学调控以及内皮微粒展开研究，通过一系列实验，发现了细胞外基质核心成员胶原家族的重要调控分子LOX和miR-21在静脉畸形发展中的重要作用；明确了TGF-β/LOX和TGF-β/Smad3/miR-21通路在静脉畸形硬化治疗中的作用和相关机制；首次揭示了TGF-β/Smad3/miR-21反馈信号环路在静脉畸形非稳态血管形成中的调控作用及其分子机制；明确了TGF-β/miR-29b信号轴可通过内皮微粒调控静脉畸形中细胞外基质沉积和管周细胞间粘附。此外，我们利用稳定表达突变型TIE2的人脐静脉内皮细胞成功构建了裸鼠静脉畸形动物模型，为相关研究提供了重要基础。本项目较系统地阐述了胶原生物学调控、内皮细胞TGF-β通路和内皮微粒在静脉畸形发展中的作用和相关机制，并成功构建了静脉畸形动物模型。以上研究成果对于揭示静脉畸形的发病机制和指导临床治疗具有重要意义。