Development of allosteric HIPK4 inhibitors as non-hormonal male contraceptives

开发变构 HIPK4 抑制剂作为非激素男性避孕药

• 批准号: 10456372
• 负责人: JAMES K CHEN
• 金额: $ 89万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10456372
• 关键词: Development; allosteric; HIPK4; inhibitors; non

Safe, effective, and reversible methods for contraception are necessary to address the 85 million unplanned pregnancies that occur worldwide each year. In addition to the negative impact of these unintended pregnancies on global sustainability, nearly one-fifth of these cases are terminated through unsafe abortions with significant risks to women’s health. Since the invention of “the Pill” in the 1950s, the vast majority of birth control options have been female-directed, including estrogen or progestin treatments, barrier methods, intrauterine devices, and tubal ligation. In contrast, men remain limited to condoms and vasectomy, which have high failure rates and incomplete reversibility, respectively. Pharmacological strategies for male contraception would help achieve parity with current female-directed options. However, hormone-based therapies can lead to metabolic disorders, mood changes, thrombosis, acne, and testicular degeneration. Non-hormonal agents in development such as retinoic acid signaling antagonists, lonidamine derivatives, and bromodomain testis-specific protein inhibitors can also have undesirable on-target side effects. Identifying new regulators of sperm development and function will be necessary to bridge this gap, and druggable testis-specific proteins are especially attractive targets. Our project focuses on one signaling protein that exemplifies this paradigm: HIPK4, a member of the homeodomain-interacting protein kinase family that is expressed in developing sperm. We observe that male mice lacking HIPK4 function are infertile but otherwise appear to have normal development, physiology, and behavior. HIPK4-deficient mice exhibit spermatogenic defects that are consistent with oligoasthenoteratozoospermia, and their misshapen sperm are incompetent for in vitro fertilization. Our investigations further indicate that HIPK4 regulates actin-driven head shaping during spermatid elongation. Our findings underscore the potential of small-molecule HIPK4 inhibitors as non-hormonal male contraceptives, particularly antagonists that target regions outside of the conserved ATP-binding pocket. Toward this goal, we will develop allosteric HIPK4 inhibitors and evaluate their effects on spermiogenesis and male fertility in animal models. The R61 phase of this project will focus on establishing a workflow for identifying and characterizing allosteric HIPK4 antagonists, including a primary protein thermal shift (PTS) assay (R61 Aim 1) and secondary/tertiary assays of inhibitor potency and selectivity (R61 Aim 2). We will also develop in silico and crystallographic protocols for studying the structural basis of HIPK4 inhibition (R61 Aim 3). After completing these milestones, we will pursue the R33 phase of this project, which includes a large-scale, high-throughput PTS screen for allosteric HIPK4 inhibitors (R33 Aim 1) and hit-to-lead optimization through medicinal chemistry and structure-based design (R33 Aim 2). We will then evaluate HIPK4 antagonists in animal models to determine their safety, efficacy, and reversibility as male contraceptives (R33 Aim 3).

需要安全、有效和可逆的避孕方法来解决 8500 万人的问题 除了这些意外怀孕的负面影响之外，世界各地每年都会发生意外怀孕。 怀孕对全球可持续性的影响，其中近五分之一是通过不安全堕胎终止的 自 20 世纪 50 年代发明“避孕药”以来，绝大多数妇女的健康都面临着重大风险。 控制选择是针对女性的，包括雌激素或孕激素治疗、屏障方法、 相比之下，男性仍然仅限于使用避孕套和输精管结扎术。 分别是高故障率和不完全可逆性。 男性避孕药理学策略将有助于实现与当前女性主导的药理学策略的平等 然而，基于激素的疗法可能导致代谢紊乱、情绪变化、血栓形成、痤疮、 和睾丸变性正在开发中，例如视黄酸拮抗剂信号传导， 氯尼达明衍生物和溴结构域睾丸特异性蛋白抑制剂也可能具有不良的靶向作用 需要确定精子发育和功能的新调节因子来弥补这一差距。 我们的项目重点关注一种信号传导。 体现这一范例的蛋白质：HIPK4，同源结构域相互作用蛋白激酶家族的成员 我们观察到缺乏 HIPK4 功能的雄性小鼠不育，但 HIPK4 缺陷小鼠在其他方面似乎具有正常的发育、生理和行为。 与少弱精子症一致的生精缺陷，其畸形精子是 我们的研究进一步表明 HIPK4 调节肌动蛋白驱动的头部。 精子细胞伸长过程中的成形。 我们的研究结果强调了小分子 HIPK4 抑制剂作为非激素男性的潜力 避孕药，特别是针对保守 ATP 结合袋之外区域的拮抗剂。 为了实现这一目标，我们将开发变构 HIPK4 抑制剂并评估其对精子发生和发育的影响。 该项目的 R61 阶段将重点关注建立雄性生育力动物模型的工作流程。 识别和表征变构 HIPK4 拮抗剂，包括主要蛋白质热位移 (PTS) 我们还将进行抑制剂效力和选择性的二级/三级测定（R61 Aim 1）和二级/三级测定（R61 Aim 2）。 开发用于研究 HIPK4 抑制的结构基础的计算机和晶体学协议（R61 Aim 3）。 完成这些里程碑后，我们将继续该项目的 R33 阶段，其中包括大规模、 高通量 PTS 筛选变构 HIPK4 抑制剂 (R33 Aim 1) 并通过点击到先导优化 然后我们将评估 HIPK4 拮抗剂的药物化学和基于结构的设计（R33 目标 2）。 动物模型以确定其作为男性避孕药的安全性、有效性和可逆性（R33 目标 3）。