Alkoxypsoralens, Small Molecule Blockers of the Voltage-Gated Kv1.3 Channel

烷氧基补骨脂素，电压门控 Kv1.3 通道的小分子阻断剂

• 批准号: 7141943
• 负责人: HEIKE WULFF
• 金额: $ 26.24万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7141943
• 关键词: autoimmune disorder; bioengineering /biomedical engineering; cell mediated lymphocytolysis test; contact dermatitis; cytotoxic T lymphocyte; disease /disorder model; drug discovery /isolation; helper T lymphocyte; high performance liquid chromatography; immunosuppression; immunotoxicity; ion channel blocker; kidney transplantation; laboratory rat; longitudinal animal study; mass spectrometry; myasthenia gravis; nanotechnology; nonhuman therapy evaluation; pharmacokinetics; potassium channel; psoralens; psoriasis; small molecule; transplant rejection

DESCRIPTION (provided by applicant): Specific K+ channel modulation offers an enormous potential for the development of new drugs. 1 channel that constitutes an especially promising therapeutic target is the voltage-gated Kv1.3 channel. Homomeric Kv1.3 channels are found in T and B lymphocytes and their expression is up-regulated in terminally differentiated effecter memory T (TEM) cells and class-switched memory B cells suggesting that Kv1.3 blockers should be useful for the treatment of autoimmune diseases such as multiple sclerosis, type-1 diabetes, psoriasis, contact dermatitis, rheumatoid arthritis and myasthenia gravis. This concept has been validated by the demonstration that autoreactive T cells from patients with multiple sclerosis and type-1 diabetes are predominantly Kv1.3-high TEM cells and that the Kv1.3 blocking peptide ShK can treat an animal model of multiple sclerosis. However, despite Kv1.3's obvious therapeutic importance, the pharmaceutical industry has so far been unsuccessful in developing selective and potent small molecule Kv1.3 blockers. With the alkoxypsoralen PAP-1 my laboratory recently identified the first small molecule inhibitor of Kv1.3 that blocks the channel with an EC50 of 2 nM and displays selectivity over the cardiac potassium channel Kv1.5. PAP-1 does not exhibit cytotoxic or phototoxic effects, is negative in the Ames test, potently inhibits the proliferation of human TEM cells and suppresses delayed type hypersensitivity (DTH), a TEM cell mediated reaction, in rats when administered intraperitoneally or orally. PAP-1 therefore, seems to constitute an excellent new tool to further explore Kv1.3 as a target for immunosuppression and could potentially be developed into orally available immunomodulator. With the help of this proposal we intend to thoroughly explore the therapeutic potential of PAP-1. Under Aim-1, we will determine PAP-1's pharmacokinetics and test which effect long-term suppression of memory cells with PAP-1 has on the immune system. Under Aim 2, we will test whether PAP-1 treats allergic contact dermatitis, an animal model for CD8+ T cell mediated skin reactions like psoriasis, and experimental autoimmune myasthenia gravis, a model for the T-cell dependent antibody-mediated autoimmune disease myasthenia gravis. Since TEM cells also play an important role in early and late-stage transplant rejection, we will further test whether PAP-1 can suppress acute and chronic rejection in a rat kidney transplant model (Aim 3). Lay: Potassium channels are proteins that tunnel the cell membrane and conduct potassium ions. 1 of these channels, called Kv1.3, is expressed in white blood cells and has been proposed as a potential new therapeutic target for the treatment of autoimmune diseases. The aims of our proposal are to test a Kv1.3 blocker that we designed in animal models of autoimmune diseases and transplant rejection.

描述（由申请人提供）：特定的 K+ 通道调制为新药的开发提供了巨大的潜力。构成特别有前途的治疗靶点的 1 通道是电压门控 Kv1.3 通道。 T 和 B 淋巴细胞中发现同源 Kv1.3 通道，其表达在终末分化效应记忆 T (TEM) 细胞和类别转换记忆 B 细胞中上调，表明 Kv1.3 阻滞剂应可用于治疗自身免疫性疾病多发性硬化症、1型糖尿病、牛皮癣、接触性皮炎、类风湿性关节炎和重症肌无力等疾病。这一概念已得到证实，即来自多发性硬化症和 1 型糖尿病患者的自身反应性 T 细胞主要是 Kv1.3 高 TEM 细胞，并且 Kv1.3 阻断肽 ShK 可以治疗多发性硬化症动物模型。然而，尽管 Kv1.3 具有明显的治疗重要性，但制药行业迄今为止尚未成功开发出选择性且有效的小分子 Kv1.3 阻滞剂。我的实验室最近通过烷氧基补骨脂素 PAP-1 鉴定出了第一个 Kv1.3 小分子抑制剂，它阻断通道的 EC50 为 2 nM，并对心脏钾通道 Kv1.5 显示出选择性。 PAP-1 不表现出细胞毒性或光毒性作用，Ames 试验呈阴性，腹膜内或口服给药时，可有效抑制人 TEM 细胞的增殖并抑制迟发型超敏反应 (DTH)，这是一种 TEM 细胞介导的反应。因此，PAP-1 似乎是进一步探索 Kv1.3 作为免疫抑制靶点的绝佳新工具，并有可能开发成口服免疫调节剂。借助该提案，我们打算彻底探索 PAP-1 的治疗潜力。在 Aim-1 项下，我们将确定 PAP-1 的药代动力学，并测试 PAP-1 长期抑制记忆细胞对免疫系统的影响。在目标 2 下，我们将测试 PAP-1 是否可以治疗过敏性接触性皮炎（CD8+ T 细胞介导的皮肤反应（如牛皮癣）的动物模型）和实验性自身免疫性重症肌无力（T 细胞依赖性抗体介导的自身免疫性疾病重症肌无力的模型） 。由于TEM细胞在早期和晚期移植排斥反应中也发挥着重要作用，我们将进一步测试PAP-1是否可以在大鼠肾移植模型中抑制急性和慢性排斥反应（目标3）。 Lay：钾通道是穿过细胞膜并传导钾离子的蛋白质。其中一种通道称为 Kv1.3，在白细胞中表达，已被提议作为治疗自身免疫性疾病的潜在新治疗靶点。我们提案的目的是在自身免疫性疾病和移植排斥的动物模型中测试我们设计的 Kv1.3 阻断剂。