组蛋白修饰在黄韧带骨化中表观遗传机制研究

Ossification of ligamentum flavum (OLF) is a common disorder of unknown etiology,although many factors have all been suggested as playing a possible pathogenetic role in the new bone growth characterizing OLF. However, up to now, the molecular mechanisms and therapies of OLF is still a difficult question in basic and clinics fields. Our research group, according to the pilot studies of clinic and pathology, discovers that the abnormal mechanical stress distribution and hyperleptinemia are thought to be important factors in the genesis and progression of OLF. To further investigate the molecular mechanism of OLF, we found Histone modification play important role and improve the progress of OLF..To clarify the function of Histone modification in ossification of ligament flavum, we will examine the expression relationships between the histone modification and osteogenic genes in OLF and non-OLF. And by using acitivitor or inhibitor of Histone modification, we will explore what kind or type of histone modification pathways were required in ossification processes in human ligament flavum cells, and which gene or genes play the critical role in this process,thus,we will clarify epigenetic mechanism of histone modification pathway in OLF. So on the basis of our studies in OLF, we will provide a solid experimental foundation for clinics to find a new idea to solve the OLF.

黄韧带骨化（OLF）的发病机制、早期诊治一直是脊柱外科的棘手难题之一。.本课题组前一国家自然基金项目以易感因素和易感基因为切入点，发现：局部应力和高.Leptin 血症是OLF 发病的重要原因，进一步探索其机制后发现组蛋白甲基化可以促进黄韧带细胞成骨分化，在OLF 发病过程中起重要作用。本课题拟进一步探索组蛋白甲基化在OLF 发病过程中作用的分子机制；观察组蛋白甲基化和甲基转移酶在正常黄韧带组织和OLF 患者的黄韧带组织及细胞中的表达与成、抑骨基因表达的相关性，并通过在人黄韧带细胞中应用信号通路抑制剂或激动剂，探索上述过程的启动环节、下游事件、不同事件间的相互关系及调控机制，从而揭示组蛋白甲基化信号通路的活化促进黄韧带细胞成骨分化的分子机制,最终为寻找临床治疗OLF 的新方法提供理论和实验依据。

黄韧带骨化（OLF）是胸椎管狭窄的主要病理因素，发病机制尚不明确。我们成功使用rhBMP2诱导建立大鼠OLF动物模型，并发现组蛋白修饰可能参与调控骨化的发生。随后，我们通过对OLF患者血液样本外显子测序及易感基因验证，证明由单核苷酸突变引起的BMP-2基因上调表达可能是引起胸椎OLF发病的病理机制之一。此外，我们继续完善黄韧带细胞培养模型，并对进行相应的分子生物学研究，先后发现长节段OLF患者的韧带细胞成骨分化潜能更强；组蛋白去乙酰化酶5和9在骨化的黄韧带细胞中表达明显下调；MiR-199b-5p通过靶向调控JAG1和Notch信号通路抑制黄韧带细胞成骨分化；MiR-132-3p通过抑制多个成骨相关基因调控黄韧带细胞成骨分化等，这些重要的结果进一步揭示了组蛋白修饰促进黄韧带细胞成骨分化的分子机制，为寻找临床治疗OLF 的新方法提供理论依据。