Targeting BRDT (testis-specific bromodomain) for Male Contraception

项目总结 男性避孕的药理学方法在医学上仍然是一个长期的挑战。近期 我们实验室的研究表明，溴域的小分子抑制剂JQ1和 表观遗传阅读器蛋白的BET亚家族是BRDT的有效抑制因子，观察到的 JQ1的避孕效果是完全可逆的。然而，JQ1是一种PAN-BET抑制剂，因此具有选择性 BRDT抑制剂需要作为安全、有效和可逆的非激素男性避孕药 治疗剂。因此，我们提出了针对生物化学的发现、优化、 避孕效果可逆性的特征、机理理解、体内评估和临床 BRDT抑制剂的翻译。在具体目标1中，我们提出了四个化学平台来发现BRDT选择性 用于男性避孕的溴域抑制剂：1)新的非明显的乙酰赖氨酸模拟物；2) 特异性靶向人类BRDT中的独特残基；3)可选择性地与两者结合的独特配体 BRDT的溴结构域；以及4)设计用于指导选择性降解的双功能小分子 BRDT蛋白。基于结构的药物设计、生化和生物物理研究将用于提高选择性 改进。对于特定目标2，从特定目标1确定的选择性BDRT抑制剂将进一步 通过迭代过程优化BRDT的细胞效力和选择性，这一迭代过程也将涉及体外 测试ADMET的性能。特指目标3将通过体内实验探索这些抑制剂的临床潜力。 男性避孕药的药代动力学研究和临床前评估，包括确定的研究 雄性小鼠的精子发生、生育能力和可逆性。

PROJECT SUMMARY A pharmacologic approach for male contraception remains a longstanding challenge in medicine. Recent research from our laboratories has shown that the small-molecule inhibitor JQ1 of the bromodomain and extraterminal (BET) subfamily of epigenetic reader proteins is a potent inhibitor of BRDT and that the observed contraceptive effect of JQ1 is completely reversible. However, JQ1 is a pan-BET inhibitor and therefore selective BRDT inhibitors are needed that can act as safe, effective, and reversible non-hormonal male contraceptive therapeutic agents. We thus propose research directed at the discovery, optimization, biochemical characterization, mechanistic understanding, in vivo evaluation of contraceptive effect reversibility, and clinical translation of BRDT inhibitors. In Specific Aim 1, we propose four chemical platforms to discover BRDT-selective bromodomain inhibitors for male contraception: 1) novel non-obvious mimetics of acetyl-lysine; 2) inhibitors that specifically target a unique residue in human BRDT; 3) unique ligands that can bind selectivly to both bromodomains of BRDT; and 4) bifunctional small molecules designed to direct selective degradation of the BRDT protein. Structure-based drug design, biochemical, and biophysical studies will be used to drive selectivity improvements. For Specific Aim 2, the selective BDRT inhibitors identified from Specific Aim 1 will be further optimized for cellular potency and selectivity for BRDT through an iterative process that will also involve in vitro testing for ADMET properties. Specific Aim 3 will explore the clinical potential of the inhibitors through in vivo pharmacokinetic studies and pre-clinical evaluation for male contraception, involving definitive studies of spermatogenesis, fertility, and reversibility in male mice.