后纵韧带骨化症（OPLL）是脊柱外科常见疾病，脊髓严重受压可导致四肢瘫痪及大小便失禁，危害巨大。申请人在前期国家自然基金资助下发现了一系列OPLL特异性致病相关的调控性RNA分子，然而这些分子的如何启动、如何相互作用以及如何导致病变进展仍未明确。近年来随着对微环境调控认识的不断深入，信号分子除了在细胞内发挥作用外，还可通过微囊泡旁分泌的形式改变局部微环境、作用于周围细胞，进而促进疾病发展。课题组在前期对OPLL韧带组织来源细胞外微囊泡进行高通量RNA测序分析后，发现直径100纳米左右的外泌体中含有OPLL致病相关microRNA分子，说明外泌体可能是OPLL细胞微环境的主要构建者。因此，本项目拟针对OPLL来源外泌体对韧带细胞成骨分化影响进行系统研究，通过体外及在体研究验证其对OPLL形成及发展的作用机制，为今后基于外泌体的靶向治疗研究提供重要理论基础。

Ossification of Posterior Longitudinal Ligament (OPLL), as one of the most common diseases in spinal surgery, can lead to quadriplegia and incontinence in patients, and is a serious disease that endangers the health of patients. In previous studies, with the support of successive national natural funds, we have found a group of OPLL-specific pathogenic microRNA molecules, but how these molecules play roles in the onset and progression of the disease is not clear. In recent years, with the deepened understanding of the regulation of microenvironment, these signaling molecules can play a role in the peripheral cells caused by the local microenvironment changes in the form of microencapsulation secretion, thus promoting the development of the disease. In the previous researches, a high-throughput RNA sequencing analysis was carried out for OPLL ligament tissue derived extracellular vesicles, and it was found that the secretion of microvesicles with a diameter of about 100 nm contained a large number of OPLL pathogenic related microRNA molecules, and may be the take an active part in the development of OPLL. Therefore, this project intends to study the effect of OPLL derived microvesicles or exosomes on the osteogenesis differentiation of ligament cells, and to verify the mechanism of its action on the formation and development of OPLL through in vitro and in vivo research, and to provide an important theoretical basis for the future research of targeted therapy.