The blockade of neuropilin-2 as a new therapeutic principle in arthritis

在类风湿性关节炎(以及结肠炎)中，我们观察到炎症组织中交感神经纤维的排斥。高浓度的交感神经递质具有抗炎作用。因此，它们的丢失可能会加剧炎症。在之前的工作中，在DFG的资助下，我们能够确定交感神经纤维排斥的两个可能原因，即所谓的神经排斥因子：它们是来自人类滑膜巨噬细胞和成纤维细胞的信号素3C(SEMA3C)和胎盘生长因子(PlGF)。与骨性关节炎或创伤对照组相比，类风湿关节炎患者SEMA3C的表达显著增加。已知SEMA3C、PlGF和VEGF165都能与交感神经末梢上的异位神经排斥因子受体Neuropilin-2结合。因此，仅阻断一种特定的神经排斥因子在体内可能没有任何效果(冗余)。本项目的主要目标是中和NeuroPilin-2，并研究这一重要受体在体外和体内的抑制作用。除了在人和小鼠的组织中产生用于免疫组织化学的神经毛细蛋白-2抗体外，还将产生一种可溶的神经毛细蛋白-2 Fc融合构建体。这种FC融合结构的中和效果将在神经生长试验中进行测试。这一结构将进一步用于关节炎的动物模型。在这项关节炎研究的延伸中，我们将展示神经纤维排斥在皮肤伤口愈合和右旋糖胺硫酸盐诱导的小鼠结肠炎中的影响。

In rheumatoid arthritis (and also in colitis) we observed repulsion of sympathetic nerve fibres in inflamed tissue. Sympathetic neurotransmitters in high concentrations exert antiinflammatory effects. Thus, their loss probably aggravates inflammation. In previous work, funded by the DFG, we were able to identify two probable causes of repulsion of sympathetic nerve fibres, so-called nerve repellent factors: These are semaphorin 3C (SEMA3C) and placental growth factor (PlGF) from human synovial macrophages and fibroblasts. Expression of SEMA3C is significantly increased in patients with rheumatoid arthritis as compared to osteoarthritis or trauma controls. It is known that SEMA3C, PlGF, and VEGF165 all bind the promiscuous nerve repellent factor receptor neuropilin-2 on sympathetic nerve terminals. Thus, blockade of only one particular nerve repellent factor may be without any effect in vivo (redundancy). It is the main goal in this project to neutralise neuropilin-2, and to study the effects of inhibition of this important receptor in vitro and in vivo. Besides the generation of antibodies against neuropilin-2 for immunohistochemistry in human and murine tissue, a soluble neuropilin-2 Fc-fusion construct will be generated. The neutralising effect of this Fc-fusion construct will be tested in the nerve outgrowth assay. This construct will be further used in an animal model of arthritis. In extension of this study in arthritis, we will demonstrate the impact of nerve fibre repulsion in cutaneous wound healing and dextrane sulphate - induced colitis in mice.