Allosteric Modulators of Dopamine Transporter as Therapeutic Agents for NeuroAIDS

项目摘要 全世界有3700多万人感染了人类免疫缺陷病毒， 仍然是一个全球公共卫生问题。尽管广泛使用抗逆转录病毒疗法（ART）， 70%的艾滋病毒阳性个体患有认知和行为缺陷，统称为艾滋病毒相关性 神经认知障碍（HAND），目前没有治疗选择。汇聚的线条 有证据表明，HIV-1转录反式激活因子（达特）蛋白在引起HIV-1感染中起着至关重要的作用。 神经毒性和认知障碍。HIV-1达特通过与关键的神经细胞相互作用发挥其神经毒性， 蛋白质，如中枢神经系统（CNS）中的单胺转运蛋白。的失调 HAND中的多巴胺（DA）神经传递通过达特蛋白与DA的直接相互作用发生 转运蛋白（DAT）对于维持DA稳态至关重要，也是可卡因的靶点。虽然大多数艺术 不能有效地穿过血脑屏障，Tat诱导的DA水平的增加加速了病毒的复制， 大脑此外，可卡因等滥用药物会加剧神经损伤。我们已发表的作品 已经证明了Tat诱导的DAT抑制是通过达特与细胞表面的变构结合位点的结合介导的， DAT，而不是通过与DA摄取位点相互作用。这为一种新的方法提供了基础， 通过开发化合物以减弱达特通过变构机制与DAT的结合来解决问题。我们最近 用DAT的小分子变构配体进行的研究表明，这些化合物能够减弱 Tat介导的DAT效应，从而提供了一个潜在的机会，开发治疗干预， 手的治疗。本文提出的研究努力是探索Tat-DAT的破坏 与DAT的小分子变构配体的相互作用，对正常DA摄取的破坏最小， 预防HAND神经认知功能障碍的治疗潜力。我们研究的主要目的是 优化先导化合物并在动物模型中进行概念验证药理学研究。本 最后，本论文的具体目标是：（1）设计合成新型的变构化合物， 使用计算机模拟性质预测具有改进的物理化学和药代动力学性质的配体， 计算对接研究与DAT-Tat复杂的模型，（2）表征的变构相互作用的 化合物与人DAT在体外鉴定具有改善的物理化学性质的优化化合物 可用于减轻Tat诱导的DAT功能障碍，以及（3）确定所选药物的功效。 化合物在减弱Tat介导的认知缺陷和可卡因在诱导型达特中的奖励作用中的作用 体内转基因小鼠。这种合作努力涉及具有医学领域互补专业知识的研究人员 化学，药物设计，生物化学和行为研究，长期目标是开发药物， 艾滋病病毒阳性患者的手牵手的治疗。

PROJECT SUMMARY More than 37 million people are living with Human Immunodeficiency Virus (HIV) infection worldwide which continues to be a global public health problem. Despite the widespread use of antiretroviral therapy (ART), up to 70% of HIV-positive individuals suffer from cognitive and behavioral deficits collectively known as HIV-associated neurocognitive disorders (HAND), for which no therapeutic options are currently available. Converging lines of evidence indicate that the HIV-1 transactivator of transcription (Tat) protein plays a crucial role in causing neurotoxicity and cognitive impairment in HAND. HIV-1 Tat exerts its neurotoxicity through interaction with crucial proteins, such as the monoamine transporters in the central nervous system (CNS). The dysregulation of dopamine (DA) neurotransmission in HAND occurs through direct interaction of Tat protein with the DA transporter (DAT) which is essential for maintaining DA homeostasis and a target of cocaine. While most ARTs cannot efficiently cross the blood-brain barrier, Tat-induced increase in DA levels accelerates viral replication in the brain. Moreover, drugs of abuse, such as cocaine, exacerbate neurological impairments. Our published work has demonstrated that Tat-induced inhibition of DAT is mediated by binding of Tat to allosteric binding site(s) on DAT, not by interacting with the DA uptake site. This provides a basis for a novel approach to address the problem by developing compounds to attenuate Tat binding to DAT by an allosteric mechanism. Our recent studies with small molecule allosteric ligands of DAT reveal that these compounds are capable of attenuating Tat-mediated effects on DAT, thus providing a potential opportunity to develop therapeutic interventions for the treatment of HAND. The research effort proposed herein is to explore the hypothesis that disruption of Tat-DAT interactions with small molecule allosteric ligands of DAT, with minimal disruption of normal DA uptake, will have therapeutic potential for prevention of neurocognitive dysfunction in HAND. The primary goal of our research is to optimize lead compounds and perform proof-of-concept pharmacological studies in animal models. To this end, the specific aims to be pursed in the proposed effort are to: (1) design and synthesize novel allosteric ligands with improved physicochemical and pharmacokinetic properties using in silico property predictions and computational docking studies with DAT-Tat complex models, (2) characterize the allosteric interaction of the compounds with human DAT in vitro to identify optimized compounds with improved physicochemical properties that can be used to alleviate Tat-induced dysfunction of DAT, and (3) determine the efficacy of selected compounds in attenuating Tat-mediated cognitive deficits and rewarding effects of cocaine in inducible Tat transgenic mice in vivo. This collaborative effort involves investigators with complementary expertise in medicinal chemistry, drug design, and biochemical and behavioral studies with the long-term goal of developing drugs for the treatment of HAND in HIV-positive patients.