Therapeutic modulation of calcium- and calciprotein particle-induced NLRP3 inflammasome activation in rheumatoid arthritis

类风湿性关节炎中钙和钙蛋白颗粒诱导的 NLRP3 炎性体激活的治疗调节

• 批准号: 511808976
• 负责人: Professor Dr. Ulf Wagner
• 金额: --
• 依托单位: Bereich Rheumatologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/511808976?language=en
• 关键词: Therapeutic; modulation; calcium; calciprotein; particle

Activation of the NLRP3 inflammasome and subsequent IL-1β release is the most powerful pro-inflammatory mechanism of the innate immune system and has been reported to drive inflammation in numerous pathological scenarios. The calcium sensing receptor is monitoring systemic calcium homeostasis in parathyroid gland and kidney, but it is also strongly expressed in immune cells and has been found to be an important pro-inflammatory mediator in inflammatory diseases. We have reported previously, that calcium-induced signaling via the calcium sensing receptor triggers NLRP3 inflammasome activation in monocytes resulting in the release of high amounts of IL-1β and other Caspase1-dependent cytokines, but also of TNF and IL-6. Recently, we could further elucidate the underlying mechanism by showing, that in the presence of sufficient calcium concentration, calciprotein particles containing phosphate and fetuin A are formed und taken up by monocyte macropinocytosis in a CaSR signaling dependent fashion. Rheumatoid arthritis is one of the most common autoimmune diseases and characterized by a destructive and often debilitating inflammation of small and medium sized joints, and in some patients also of internal organs. Long-term consequences of the disease, in particular in patients with poorly controlled disease activity, include a significantly decreased life expectancy primarily due to an increased frequency of cardiovascular events. In a clinical study, our group could show that ionized calcium induces increased IL-1β responses in monocytes from patients with rheumatoid arthritis, and that RA monocytes take up calciprotein particles at a much higher rate than control monocytes. In this project, we will test various approaches to interfere therapeutically with this pathway, in order to inhibit calcium induced inflammation in RA. First, we will use pharmacologic and genetic methods to inhibit CaSR signaling and investigate the course of autoimmune arthritis under those conditions. In the second approach, arthritic mice will be treated with inhibitors of macropinocytosis in order to modulate the course of arthritis. And thirdly, Cathepsin inhibitors and cathepsin B-deficient mice will be used to investigate lysosomal breakdown of calciprotein particles in arthritis. In addition, we will further investigate the intracellular pathway leading from CPP degradation to NLRP3 activation and IL-1β release. The relevance of each step of this pathway for the initiation and perpetuation of inflammation will be tested using genetic mouse model of arthritis as well as collagen- and collagen-antibody-induced arthritis. At the conclusion of the project, we will have identified the most promising therapeutic approach to the inhibition of calcium induced NLRP3 inflammasome activation in human rheumatoid arthritis.

NLRP 3炎性体的激活和随后的IL-1β释放是先天免疫系统最强大的促炎机制，并且据报道在许多病理情况下驱动炎症。钙敏感受体监测甲状旁腺和肾脏中的全身钙稳态，但它也在免疫细胞中强烈表达，并已被发现是炎性疾病中重要的促炎介质。我们之前已经报道过，通过钙敏感受体的钙诱导的信号传导触发单核细胞中的NLRP 3炎性体活化，导致释放大量的IL-1β和其他Caspase 1依赖性细胞因子，以及TNF和IL-6。最近，我们可以进一步阐明潜在的机制，显示，在足够的钙浓度的存在下，含有磷酸盐和胎球蛋白A的钙蛋白颗粒的形成和采取的单核细胞巨胞饮作用中的CaSR信号依赖的方式。风湿性关节炎是最常见的自身免疫性疾病之一，其特征在于中小型关节的破坏性和经常使人衰弱的炎症，并且在一些患者中还包括内脏器官。该疾病的长期后果，特别是在疾病活动控制不佳的患者中，包括主要由于心血管事件频率增加而导致的预期寿命显著降低。在一项临床研究中，我们的小组可以表明，离子钙诱导类风湿性关节炎患者单核细胞中IL-1β反应增加，RA单核细胞以比对照单核细胞高得多的速率摄取钙蛋白颗粒。在本项目中，我们将测试各种方法来治疗性干扰这一途径，以抑制RA中钙诱导的炎症。首先，我们将使用药理学和遗传学方法来抑制CaSR信号传导，并在这些条件下研究自身免疫性关节炎的过程。在第二种方法中，将用巨胞饮抑制剂治疗关节炎小鼠以调节关节炎的进程。第三，组织蛋白酶抑制剂和组织蛋白酶B缺陷小鼠将用于研究关节炎中钙蛋白颗粒的溶酶体分解。此外，我们将进一步研究从CPP降解到NLRP 3激活和IL-1β释放的细胞内途径。将使用关节炎以及胶原蛋白和胶原蛋白抗体诱导的关节炎的遗传小鼠模型来测试该途径的每个步骤与炎症的起始和持续的相关性。在项目结束时，我们将确定最有前途的治疗方法来抑制钙诱导的NLRP 3炎性小体在人类类风湿性关节炎中的激活。