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

我们正在研究一种基于细胞中共同途径的治疗急性关节炎的新方法 渗透损害骨骼和关节。炎症性关节炎每年导致数千人残疾。它发生 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。数以百万计的成年人与 慢性RA也有类似的特征。炎症性关节炎通常需要具有严重副作用的治疗。 在关节炎后期，骨侵蚀是导致严重疼痛和虚弱的主要问题。没有小 可用于专门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（称为 Orai）来抑制。 Orai 拮抗剂，N-甲基- 3,4-二氯丙苯胺（N-MeDCPA），抑制破骨细胞成熟并强烈抑制胶原蛋白- 即使在可测量到关节炎症状后，仍可在小鼠中诱导关节炎（CIA）。我们建议 用 N-MeDCPA 药理学抑制 CRAC 通道将防止关节炎刺激引起的骨侵蚀 无重大不良影响。 我们假设 Orai 通道介导的 Ca2 信号调节破骨细胞的最终分化， 对 T 细胞的相关影响可能会加强急性关节炎中骨和关节的保护。我们预计毒性 当免疫系统成熟的动物接受数周治疗时，N-MeDCPA 较低。我们建议 除了 Ca2 机械实验之外，还进行全面的药代动力学和毒代动力学测试 信号传导、免疫学和骨生物学专业知识。 第一阶段 - 目标 1： - 药物配方、给药途径优化和 Orai 特异性。 N- MeDCPA 是脂溶性的。该目标将定义合适的 N-纳米颗粒 (NP) 或脂质体制剂 MeDCPA 用于肠胃外或口服给药。药物血液浓度与易用性/便利性和有效性的关系将 进行评估。 I 期 – AIM 2： - 使用 CIA 模型完成 N-MeDCPA 的剂量反应研究。拥有 证明 N-MeDCPA 可以防止有症状小鼠的骨侵蚀并抑制炎症， 这一目标的重点是确定其对中央情报局标准措施、关节炎指数、骨质侵蚀、 使用优化的给药方案通过 µCT 测量体积和炎症（肿胀）。 II 期 - AIM 1：非 GLP 和 GLP 下 N-MeDCPA 的药理学和毒理学评估 体外和体内条件。合同研究组织将进行一系列广泛的测试 （CRO）与 ExesaLibero 签订合同（参见科文斯的支持信）。 II 期 - 目标 2：确定 N-MeDCPA 的治疗潜力。对于证明 N- 至关重要 MeDCPA 将提高护理标准/生活质量，证实两性具有同等效力 使用 SKG 小鼠，确定其细胞特异性，在测试中检查 N-MeDCPA 的潜在免疫毒性 CRO 未涵盖，并探索 N-MeDCPA 与 其他当前的非生物治疗，例如甲氨蝶呤。我们还将研究对人体细胞的体外影响 以避免啮齿动物与人类生理差异的陷阱。 第二阶段 - 目标 3：评估 N-MeDCPA 的特异性和作用机制。我们将评估行动 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。 N-MeDCPA 作为治疗骨侵蚀的药物的开发有望预防生命- 改变与 RA 相关的衰弱，有效且低毒性。

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.