Tyro3受体酪氨酸激酶在类风湿关节炎单核/巨噬细胞调控机制中的研究

Rheumatoid arthritis(RA) is a chronic autoimmune disease with articular cartilage and joint destruction characterized by over-activiation of immune cells such as monocytes/macrophages, release of inflammatory cytokines leading to immune disbalance and multi-articular involvement. As one of the sub-members of TAM family receptor tyrosine kinases, Tyro3 receptor tyrosine kinase are pleiotropic inhibitiors in regulating immune effector of monocytes/macrophages by negative feedback loop, participating in the molecular mechanisms in autoimmune disease. In our study, Tyro3 KO mice are used to explore the regulatory mechanisms of Tyro3 TK signaling pathway on monocyte/macrophage differentiation and joint destruction. Plasmid transfection and siRNA interference will be performed to study the regulating role of Tyro3TK on the differentiation of monocytes/macrophages cell lines, release of cytokines and destruction of bone or cartilage. We will also compare the expression patterns of Tyro3 receptor tyrosine kinase on monocytes/macrophages in circulating blood, synovial fluid and synovium, and analyze the correlation between Tyro3 TK expression and clinical features in RA. In summary, this study will explore the regulatory function of Tyro3 receptor tyrosine kinase on monocytes/macrophages by molecular, cellular and animal model. The results may provide new evidence for selectively targeting it for RA therapies.

类风湿关节炎（RA）是一种以关节软骨与骨侵蚀病变为主要特征的慢性自身免疫病，发病过程中伴有单核/巨噬细胞等免疫细胞的过度活化和炎症因子释放，导致机体免疫失衡及多关节损伤。研究提示，Tyro3受体酪氨酸激酶（TK）是TAM TK亚家族成员之一，可通过负反馈调节单核/巨噬细胞的免疫效应，参与自身免疫病的发生。本课题将利用Tyro3TK基因敲除小鼠，探讨Tyro3TK对体内、外单核/巨噬细胞亚群分化及骨破坏中的调控作用及其机制；应用质粒转染和siRNA技术，探讨Tyro3TK对单核/巨噬细胞亚群的免疫调节及破骨细胞形成的影响；比较Tyro3TK在外周血、滑液及滑膜组织病理中单核/巨噬细胞亚群的表达差异，分析其与RA临床表型的关系；进而从分子水平、细胞水平及动物模型三个层面探讨在RA发病中Tyro3TK对单核/巨噬细胞亚群中的调控机制，为探索RA新的治疗靶点提供前期实验依据。

【研究背景】Tyro3受体酪氨酸激酶是TAM受体酪氨酸激酶（Tyro3/Axl/Mer Receptor Tyrosine Kinase, TAMTK）受体亚家族的成员之一。单核/巨噬细胞在RA发病过程中发挥重要作用。研究提示，Tyro3TK可通过负反馈调节单核/巨噬细胞的免疫效应，参与自身免疫病的发生。【研究内容】1.可溶性Tyro3受体酪氨酸激酶在类风湿关节炎中的临床意义。2.Tyro3受体酪氨酸激酶在类风湿关节炎滑膜病理损伤的相关性研究。3. Tyro3受体酪氨酸激酶在类风湿关节炎成纤维样滑膜细胞中的作用。4.Tyro3受体酪氨酸激酶在类风湿关节炎单核/巨噬细胞亚群中的表达及作用。5.Tyro3受体酪氨酸激酶在类风湿关节炎骨破坏中的作用。6.Tyro3TK在血清诱导关节炎模型小鼠发病中的作用。【研究结果】1.sTyro3TK水平在RA血清中明显升高，且与RA的肿胀关节数、压痛关节数及Sharp评分等多项临床指标呈正相关趋势。2.RA患者滑液、滑膜组织及滑膜成纤维细胞Tyro3TK表达升高，可能与参与RA的发病。3.Tyro3TK在RA患者经典型单核/细胞亚群表面升高，并可通过促进RA破骨细胞的形成导致RA发病。4. Tyro3TK可能通过促进RAFLS迁移和侵袭，促进RAFLS所介导的CD4+T细胞向Th1和Th17细胞的分化参与到RA的发病。5.利用Tyro3TK基因敲除小鼠，发现Tyro3TK可促进血清诱导关节炎小鼠发病。【科学意义】本研究为探讨RA发病机制提供了新的思路，也为针对Tyro3受体酪氨酸激酶的靶向性治疗提供了基础研究的依据，具有一定的应用前景。