Allosteric Modulators of Dopamine Transporter as Therapeutic Agents for NeuroAIDS

项目总结 全世界有超过3700万人感染了人类免疫缺陷病毒(HIV)， 仍然是一个全球性的公共卫生问题。尽管广泛使用抗逆转录病毒疗法(ART)，但高达 70%的HIV阳性患者患有统称为HIV相关的认知和行为缺陷 神经认知障碍(手)，目前没有治疗选择。会聚的线条 有证据表明，HIV-1转录反式激活因子(TAT)蛋白在导致 手部神经毒性和认知功能障碍。HIV-1 Tat通过与关键分子相互作用发挥神经毒性作用 蛋白质，如中枢神经系统(CNS)中的单胺转运体。失调性疾病 手部的多巴胺(DA)神经传递是通过TAT蛋白与DA直接相互作用而发生的 转运蛋白(DAT)是维持DA动态平衡所必需的，也是可卡因的靶标。虽然大多数艺术 不能有效穿越血脑屏障，TAT诱导的DA水平增加加速病毒复制 大脑。此外，滥用毒品，如可卡因，会加剧神经损伤。我们出版的作品 已证明TAT对DAT的抑制作用是通过TAT与变构结合位点(S)结合介导的。 DAT，而不是通过与DA摄取部位相互作用。这为解决以下问题的新方法提供了基础 问题是开发化合物以变构机制减弱TAT与DAT的结合。我们最近 对DAT的小分子变构配体的研究表明，这些化合物能够减弱 TAT介导的对DAT的影响，从而为开发治疗干预措施提供了潜在的机会 手的治疗。本文提出的研究努力是探索TAT-DAT中断的假说 与DAT的小分子变构配体的相互作用，在最小程度上破坏正常的DA摄取，将 预防手部神经认知功能障碍的治疗潜力。我们研究的主要目标是 优化先导化合物并在动物模型中进行概念验证药理研究。对这件事 最后，本研究的具体目标是：(1)设计和合成新型变构 具有改进的物理化学性质和药代动力学性质的配体用于硅胶性质预测和 与DAT-TAT复杂模型的计算对接研究，(2)表征了变构相互作用 体外与人DAT结合鉴定物化性能改善的优化化合物 可用于缓解TAT诱导的DAT功能障碍，以及(3)确定所选药物的疗效 减轻TAT介导的认知障碍的化合物和可卡因在诱导性TAT中的奖赏效应 体内转基因小鼠。这项合作工作涉及具有互补医学专业知识的研究人员。 化学，药物设计，生化和行为学研究，长期目标是开发药物治疗 HIV阳性患者的手部治疗。

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.