Targeting Na,K-ATPase alpha4 for male contraception

靶向 Na,K-ATPase α4 的男性避孕

• 批准号: 10031740
• 负责人: V GUSTAVO BLANCO
• 金额: $ 54.49万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10031740
• 关键词: ATPase inhibitory protein; Affect; Affinity; Animals; Antihistamines; Appearance; Area; Binding; Binding Proteins; Biochemical; Biological; Biological Availability; Biological Markers; Cell membrane; Cells; Characteristics; Chemicals; Clinical; Clinical Research; Contraceptive Agents; Contraceptive methods; Data; Drug Kinetics; Drug Targeting; Effectiveness; Epididymis; Ethers; Female; Fertility; Fertilization in Vitro; Future; Germ Cells; Gland; Goals; Human; Hyperactive behavior; In Vitro; Infertility; Investigational Drugs; Ions; Knockout Mice; Lead; Male Contraceptive Agents; Male Infertility; Maximum Tolerated Dose; Meiosis; Membrane Potentials; Metabolic; Metabolism; Mus; Mutation; Na(+)-K(+)-Exchanging ATPase; Oral; Oral Contraceptives; Ouabain; Partner in relationship; Permeability; Ph+ ALL; Pharmaceutical Chemistry; Pharmacology; Pilot Projects; Plasma; Population; Property; Protein Isoforms; Proteins; Public Health; Research; Safety; Series; Site; Solubility; Source; Specificity; Sperm Capacitation; Sperm Motility; Sperm Tail; Spermatogenesis; Sterility; Surface; System; Testing; Testis; Toxic effect; Validation; Woman; absorption; analog; base; birth control; cell motility; druggable target; efficacy study; experimental study; extracellular; improved; in silico; in vivo; inhibitor/antagonist; male; male fertility; men; molecular size; monolayer; novel; pre-clinical; preclinical study; progenitor; programs; reproductive tract; reversible contraceptive; scaffold; scale up; side effect; small molecule; sperm cell; sperm function; unintended pregnancy; virtual screening

PROJECT SUMMARY / ABSTRACT The rapidly growing world population and the high rate of unintended pregnancies make contraception a need and a priority for any public health program. While several contraceptive methods, with varying efficacy are currently available for women, a more comprehensive approach to birth control requires extending contraception to males. However, a safe, effective and reversible contraceptive for men is still unavailable. An attractive approach to develop male contraceptives consists in targeting proteins that are specifically expressed in sperm and are required for sperm fertility. We have shown that Na,K-ATPase α4 (NKAα4), a plasma membrane ion transporter which exchanges cytoplasmic Na+ for extracellular K+, is a validated target for male contraception. NKAα4 is uniquely expressed in testis male germ cells after meiosis, is particularly abundant in the sperm flagellum, and is critical for sperm function. Deletion of NAKα4 in mice results in complete sterility of only the male but not the female animals. NKAα4 is essential for sperm motility and sperm capacitation. Its activity maintains sperm intracellular Na+ levels ([Na+]i) and several vital sperm parameters, including membrane potential (Vm), intracellular Ca+2 ([Ca2+]i) and pH. From a biochemical standpoint, NKAα4 has a particularly high affinity for ouabain, the specific inhibitor of Na,K-ATPase. We took advantage of this property to specifically target NKAα4 and block its function to achieve male infertility. We synthesized a series of small molecule compounds, which can selectively bind to the high ouabain affinity site of NKAα4. Some of these compounds inhibit NKAα4 and affect sperm motility both in vitro and after administration to mice. This provides strong evidence for the suitability of NKAα4 as a pharmacological target and our compounds as agents that can be used for the control of male fertility. However, before NKAα4 inhibitors can be moved forward into their application as male contraceptives, it is necessary that their efficacy, drug-target interaction, biomarkers for their in vitro and vivo specificity, side effects, mechanisms of action and pharmacokinetic parameters are identified and optimized for future clinical use. We will test this in two aims. In specific aim 1, we will develop compounds with the capacity to selectively inhibit NKAα4 and block sperm function, which will be ready for testing in mice. Then, during specific aim 2, we will perform studies to obtain preclinical validation to advance the NKAα4 inhibitors as male contraceptives. A series of rigorous approaches from the medicinal chemistry and biological areas will be used to identify the compounds which will have the characteristics that will be necessary for male contraception. This research will be essential to fulfill the highly desired unmet goal of obtaining a non-hormonal pharmacological agent that could be used as an oral, reversible agent for the control of male fertility.

项目概要/摘要 世界人口的迅速增长和意外怀孕的高发生率使得避孕成为一种 任何公共卫生计划的需求和优先事项。虽然避孕方法有多种，但效果各异 目前可供女性使用，但更全面的节育方法需要延长 男性避孕。然而，目前还没有一种安全、有效、可逆的男性避孕药具。一个 开发男性避孕药的一个有吸引力的方法在于针对特定的蛋白质 在精子中表达，是精子生育能力所必需的。我们已经证明 Na,K-ATP 酶 α4 (NKAα4) 将细胞质 Na+ 交换为细胞外 K+ 的质膜离子转运蛋白是经过验证的靶标 用于男性避孕。 NKAα4 在减数分裂后的睾丸雄性生殖细胞中独特表达，特别是 精子鞭毛中含量丰富，对精子功能至关重要。小鼠中 NAKα4 的缺失导致 仅雄性动物完全不育，雌性动物不完全不育。 NKAα4 对于精子活力和精子至关重要 获能。其活性维持精子细胞内 Na+ 水平 ([Na+]i) 和几个重要的精子参数， 包括膜电位 (Vm)、细胞内 Ca+2 ([Ca2+]i) 和 pH。从生化角度来看，NKAα4 对 Na,K-ATP 酶的特异性抑制剂哇巴因 (ouabain) 具有特别高的亲和力。我们利用了这一点 特异性靶向NKAα4并阻断其功能以实现男性不育。我们合成了一系列 小分子化合物，可以选择性地结合NKAα4的哇巴因高亲和力位点。一些 这些化合物抑制 NKAα4 并影响体外和小鼠给药后的精子活力。这 为 NKAα4 作为药理学靶点的适用性以及我们的化合物作为 可用于控制男性生育能力的药物。然而，在 NKAα4 抑制剂可以被移动之前 推进其作为男性避孕药的应用，有必要确定其功效、药物-靶标相互作用、 生物标志物的体外和体内特异性、副作用、作用机制和药代动力学 确定并优化参数以供将来的临床使用。我们将在两个目标上对此进行测试。在具体目标1中， 我们将开发能够选择性抑制NKAα4并阻断精子功能的化合物，这将 准备好在小鼠身上进行测试。然后，在具体目标 2 期间，我们将进行研究以获得临床前验证 推进 NKAα4 抑制剂作为男性避孕药的发展。一系列严格的医学方法 化学和生物领域将用于鉴定具有以下特征的化合物： 是男性避孕所必需的。这项研究对于实现高度期望的未实现目标至关重要 获得可用作口服、可逆性药物的非激素药物制剂 控制男性生育能力。