Prevention of arthritis-induced bone erosion by inhibiting osteoclast differentiation by the haloanilide, N-Methyl Dichloropropionaniline

我们正在研究一种新的治疗急性关节炎的方法，该方法基于细胞内的共同途径。 渗入破坏骨骼和关节的物质。炎症性关节炎每年使成千上万的人致残。它发生了 在儿童和成人中，在创伤和感染后，但大多数病例是特发性的。数百万成年人与 慢性类风湿关节炎，具有相似的特征。炎症性关节炎通常需要有严重副作用的治疗。 在后来的关节炎中，骨侵蚀是一个主要问题，导致严重的疼痛和虚弱。有没有小的 专用于治疗关节炎骨侵蚀的分子药物。我们发现破骨细胞的成熟是 通过阻断钙释放激活的钙通道被抑制，称为ORAI。Orai拮抗剂N-甲基- 3，4-二氯丙基苯胺(N-MeDCPA)抑制破骨细胞成熟，强烈抑制胶原蛋白合成。 在小鼠中诱发关节炎(CIA)，即使在关节炎症状可测量之后。我们建议 用N-MeDCPA药理抑制CRAC通道可防止关节炎刺激引起的骨侵蚀 没有重大不良反应。 我们假设，ORAI通道介导的钙信号调节破骨细胞的最终分化， 对T细胞的相关作用可能加强了急性关节炎患者的骨骼和关节的保护。我们预计它的毒性 在免疫系统成熟的动物中，当治疗数周时，N-MeDCPA水平较低。我们建议 全面的药代动力学和毒代动力学测试以及钙的机械实验 信号、免疫学和骨骼生物学专业知识。 第一阶段-目标1：药物配方、给药途径优化和ORAI特异性。vt.N- MeDCPA是脂溶性的。这一目标将定义一种合适的纳米颗粒(NP)或脂质体配方。 MeDCPA用于静脉注射或口服。药物血药浓度与易用性/便利性和有效性将 被评估。 阶段I-目标2：-使用CIA模型完成N-MeDCPA的剂量-反应研究。拥有 证明N-MeDCPA可以预防有症状的小鼠的骨侵蚀和抑制炎症， 这一目标的重点将是确定其对照标准CIA措施、关节炎指数、骨侵蚀、 使用优化的剂量方案，按微CT计算的体积和炎症(肿胀)。 第二阶段-目标1：N-MeDCPA在非GLP和GLP下的药理学和毒理学评价 体外和体内条件。一套广泛的测试将由合同研究机构进行 (CRO)根据与ExesaLibero的合同(见Covance的支持函)。 第二阶段-目的2：确定N-MeDCPA的治疗潜力。对证明N- MeDCPA将提高护理/生活质量的标准，是对两性同等有效性的确认 使用SKG小鼠，测定其细胞特异性，检查N-MeDCPA的潜在免疫毒性 未被CRO覆盖，并探索N-甲基二氯丙烷与 其他目前的非生物治疗，例如甲氨蝶呤。我们还将研究其对人体细胞的体外影响。 避免了啮齿动物与人类生理差异的陷阱。 第二阶段-目的3：评估N-MeDCPA的特异性和作用机制。我们将对行动进行评估 N-MeDCPA对单核细胞向破骨细胞分化的影响，并研究其可能的副作用 成骨细胞及其对离子通道的特异性。 作为骨侵蚀治疗药物的N-MeDCPA的开发有望防止生命- 改变与类风湿性关节炎相关的虚弱，有效且毒性低。

We are working on a new approach to treating acute arthritis based on a common pathway in the cellular infiltrates that damage bones and joints. Inflammatory arthritis disables thousands of people each year. It occurs in children and adults, after trauma and infections but most cases are idiopathic. Millions of adults live with chronic RA, which has similar features. Inflammatory arthritis often requires treatments with serious side effects. Later in arthritis, bone erosion is a major problem that causes severe pain and debilitation. There is no small molecule drug available to specifically treat arthritic bone erosion. We show that osteoclast maturation is suppressed by blocking a calcium-release activated calcium channel, called Orai. A Orai antagonist, N-methyl- 3,4-dichloropropionaniline (N-MeDCPA), suppressed osteoclast maturation and strongly suppressed collagen- induced arthritis (CIA) in mice, even after symptoms of arthritis were measureable. We propose that pharmacologically suppressing CRAC channels with N-MeDCPA will prevent bone erosion due to arthritic stimuli without major adverse effects. We hypothesize that Ca2+ signals mediated by Orai channels modulate final differentiation of osteoclasts, and that related effects on T cells might reinforce bone and joint sparing in acute arthritis. We expect toxicity of N-MeDCPA to be low when treatment is for several weeks in animals with mature immune systems. We propose comprehensive pharmacokinetic and toxicokinetic testing in addition to mechanistic experiments with Ca2+ signaling, immunology, and bone biology expertise. Phase I - AIM 1: - Drug formulation, route of administration optimization and Orai specificity. N- MeDCPA is lipid soluble. This aim will define a suitable nanoparticle (NP) or liposome formulation of N- MeDCPA for parenteral or oral administration. Drug blood levels versus ease/convenience and effectiveness will be assessed. Phase I – AIM 2: - Complete the dose-response studies of N-MeDCPA using the CIA model. Having demonstrated that N-MeDCPA can prevent bone erosion and arrest inflammation in symptomatic mice, the emphasis of this aim will be to define its effect against the standard CIA measures, arthritic index, bone erosion, volume by µCT and inflammation (swelling) using the optimized dosing regimen. Phase II - AIM 1: Pharmacology and toxicology assessment of N-MeDCPA under non-GLP and GLP conditions in vitro and in vivo. An extensive suite of tests will be performed by a contract research organization (CRO) under contract with ExesaLibero (see letter of support from Covance). Phase II - AIM 2: Determine the therapeutic-potential of N-MeDCPA. Critical to demonstrating that N- MeDCPA will improve the standard of care/quality of life, is confirmation of equal effectiveness in both sexes using SKG mice, determining its cellular specificity, checking for potential immunotoxicity of N-MeDCPA in tests not covered by the CRO and exploring possible additive/synergistic effects of N-MeDCPA in combination with other current non-biological treatments, e.g., methotrexate. We will also study the in vitro effects on human cells to avoid the pitfall of rodent-human physiological differences. Phase II - AIM 3: Assess the specificity and mechanism of action of N-MeDCPA. We will assess the action of the N-MeDCPA on monocyte differentiation to osteoclasts, and investigate the possible side effects on osteoblasts and its specificity for ion channels. The development of N-MeDCPA as a drug for treatment of bone erosion promises to prevent the life- changing debilitation associated with RA, effectively with low toxicity.