Pharmacological validation of adenylyl cyclase 1 as a drug target for chronic pain

慢性疼痛每年给美国造成超过6350亿美元的损失，但患者得不到足够的缓解 从可获得的药物中脱颖而出，并经常对药物产生依赖。这些观察结果突显了 确定作用于独特靶点的治疗慢性疼痛的新药物。遗传学、神经生物学和临床前研究 研究表明，腺酰环化酶1型(AC1)可能提供了新的药物靶点。AC1击倒 与小鼠对照组相比，小鼠(AC1-/-)表现出炎症和神经病理性疼痛的减轻或消失。 使用AC1小分子抑制剂NB001进行的临床前研究表明，NB001可以减轻慢性疼痛 小鼠和大鼠的反应(即炎症反应和神经性反应)。类似地，我们最近已经证明了一个 新型AC1抑制剂ST034307也减轻了小鼠模型中的炎性疼痛。这些研究是一致的 前提是AC1是慢性疼痛抑制剂的新靶点。不幸的是，NB001和ST034307 有阻碍进一步发展的重大问题和责任。为此，我们最近筛选了一部 化学图书馆藏品，使我们能够确定用于开发新型AC1的嘧啶酮支架 抑制剂。根据几个有希望的标准，这个脚手架被优先用于从点击到领先的优化。初步 构效关系研究首次揭示了具有亚微摩尔分子的化合物 AC1的效力，以及相对于密切相关的AC8的选择性。此外，初步的体内研究与领先 化合物在慢性疼痛的动物模型中显示出活性。尽管有这些令人振奋的观察结果，但领先的 化合物的水溶解度极低。我们建议对这一点进行药物化学优化。 支架开发有效和选择性的AC1活性抑制剂，作为下列特定条件下的新探针 目的：特效靶1将用药物化学优化的嘧啶酮支架开发有效 类药物AC1选择性分子探针。具体目标2将确立该药的药理特异性 利用一套体外模型分析方法对探针分子进行检测，并探讨其活性机制。另外， 我们将利用迭代药物化学和药理学进行体内临床前药代动力学试验。 然后，特殊目标3将使用最好的分子来探索AC1抑制剂的体内药理活性 在炎症性疼痛、条件性位置偏爱和阿片类药物戒断的小鼠模型中。在这个结束的时候 研究，我们将为研究界提供具有&lt；100 nm AC1效力的化学探针，&gt；30倍 与其他急性冠脉综合征和相关的中枢神经系统靶点的选择性，以及体内疗效。这些新的探测器将提供必要的 验证AC1作为治疗慢性疼痛的新的安全药物靶点的工具。

Chronic pain costs the US more than $635 billion per year, however, patients fail to receive adequate relief from the available drugs and often become drug-dependent. These observations highlight the importance for identifying new agents acting on unique targets to treat chronic pain. Genetic, neurobiological, and preclinical studies have suggested that adenylyl cyclase type 1 (AC1) may provide that new drug target. AC1 knock out mice (AC1-/-) show reduced or absent inflammatory and neuropathic pain when compared to littermate controls. Preclinical studies with a small molecule inhibitor of AC1, NB001 revealed that NB001 reduced chronic pain responses (i.e. inflammatory and neuropathic) in both mice and rats. Similarly, we have recently shown that a novel AC1 inhibitor, ST034307 also reduced inflammatory pain in a mouse model. These studies are consistent with the premise that AC1 is a new target for inhibitors of chronic pain. Unfortunately, both NB001 and ST034307 have significant issues and liabilities preventing further development. To that end, we have recently screened a chemical library collection that allowed us to identify a pyrimidinone scaffold for the development of novel AC1 inhibitors. This scaffold was prioritized for hit-to-lead optimization based on several promising criteria. Preliminary structure-activity relationship (SAR) studies have revealed for the first time compounds with sub-micromolar potency at AC1, as well as selectivity versus the closely-related AC8. Further, initial in vivo studies with a lead compound reveal activity in an animal model of chronic pain. Despite these promising observations, the lead compounds suffer from extremely low aqueous solubility. We propose medicinal chemistry optimization of this scaffold to develop potent and selective inhibitors of AC1 activity as novel probes under the following Specific Aims: Specific aim 1 will use medicinal chemistry optimization of the pyrimidinone scaffold to develop potent drug-like AC1-selective molecular probes. Specific aim 2 will establish the pharmacological specificity of the probe molecules using a set of in vitro model assays and explore the mechanisms for probe activity. Additionally, we will execute in vivo preclinical pharmacokinetic testing with iterative medicinal chemistry and pharmacology. Specific aim 3 will then use the best molecules to explore the in vivo pharmacological activity of the AC1 inhibitors in a mouse model of inflammatory pain, conditioned place preference, and opioid withdrawal. At the end of this study, we shall provide the research community with chemical probes with < 100 nM AC1 potency, > 30-fold selectivity vs other ACs and related CNS targets, and in vivo efficacy. These new probes will provide essential tools to validate AC1 as a new and safe drug target in the treatment of chronic pain.