Positive Allosteric Modulators as PET Imaging Ligans for mGluR4

作为 mGluR4 PET 成像配体的正变构调节剂

基本信息

批准号：
9358362
负责人：
ANNA-LIISA BROWNELL
金额：
$ 64.56万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-30 至 2021-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9358362
关键词：
Academia Affect Affinity American Anti-HIV Agents Antiparkinson Agents Binding Binding Proteins Binding Sites Biological Biological Availability Blood Blood Volume Brain Brain imaging Cell Line Cells Central Nervous System Diseases China Clinical Trials Computer Simulation Data Development Diagnostic Disease Dopamine Dose Drug Compounding Drug Design Drug Kinetics Equilibrium Evaluation Fluorine Future GRM5 gene Germany Glutamates Goals Health Care Costs Human Image India Industry International Investigation Investigational New Drug Application Japan Kinetics Knockout Mice Label Lead Letters Ligands Location Magnetic Resonance Imaging Medical Metabolic Metabolism Modeling Neurodegenerative Disorders Neurons Parkinson Disease Pathology Pathway interactions Penetration Pharmaceutical Preparations Pharmacology Physiological Plasma Positron-Emission Tomography Primates Process Property Publications Publishing Radiation Radiolabeled Rattus Research Resolution Series Site Structure Synapses System Testing Therapeutic Therapeutic Uses Time Toxicology Tracer Transformed Cell Line Treatment Cost Work base computational chemistry cross reactivity drug development drug discovery gamma-Aminobutyric Acid imaging study in vivo in vivo imaging interest metabotropic glutamate receptor 4 nervous system disorder neural circuit neurotransmission neurotransmitter release novel therapeutic intervention positive allosteric modulator pre-clinical presynaptic presynaptic neurons radiotracer receptor receptor function theories therapeutic target usability

项目摘要

ABSTRACT: Half a million Americans suffer from Parkinson’s disease (PD) and the incurring health cost is $6 billion in a year. There are several other neurological disorders with extremely high cost for treatment, but in this context the focus is on the disorders, which have strong connection to glutamate neurotransmission. Presynaptic location of mGlu4 makes them important contributors for glutamate neurotransmission since glutamate as well as dopamine is released from the presynaptic site of the neuron and activation of mGlu4 can inhibit the release of neurotransmitters such as glutamate and GABA and thus balance neurotransmission through direct and indirect pathways in PD. Several recent publications propose especially mGlu4 as therapeutic target for different neurological diseases including PD. We have extensively investigated positive allosteric modulators (PAMs) as PET imaging ligands for mGlu4. We investigated also biological activity of the developed compounds using pharmacological MRI approaches. These studies opened a new way to characterize compounds and explore their usability for therapeutic purposes. We have synthetized 32 different compounds based on two different chemo-types of the mGlu4 PAMs. Six of these compounds have been characterized with in vivo studies as PET imaging ligands for mGlu4. The main limitation in our developed ligands has been fast washout and metabolism, even though binding affinities have been decent. We also developed specific cell lines to express mGlu4 and the cell studies have been fundamental in ligand characterization to determine the structure-affinity relationship (SAR) of our experimental PAMs and determine co-operative relationship between endogenous glutamate binding to orthosteric binding sites and affinity of allosteric modulators. These approaches are radically different from classical approach in which orthosteric ligands compete with endogenous ligands at the same binding site. Based on the pioneering work and worldwide interest we are looking for to develop especially fluorine-18 labeled positive allosteric imaging ligands for mGlu4 allowing medical applications and distribution of the ligands. Precisely, in Aim 1 we are proposing to synthesize two F-18 labeled lead compounds from the N- phenylpicolinamide- and thiazolopyrazole-based mGlu4 PAMs to study their imaging efficacy, Bmax, selectivity, brain penetration, pharmacokinetics, metabolic stability and other properties. In Aim 2 we will synthesize new series of eight fluorine-containing N-phenylpicolinamide derivatives and twelve fluorine- containing thiazolopyrazole derivatives for SAR analyses. This effort will be supported by computational chemistry. Two best compounds will be selected for the development as PET imaging ligands for mGlu4. In Aim 3 we will conduct in vivo characterization of these ligands using mGlu4 knockout mice, rat and primate models with an ultimate goal to validate the best compound for human studies and obtain IND approval.

摘要： 50 万美国人患有帕金森病 (PD)，由此产生的健康成本为其他几种神经系统疾病的治疗费用每年高达 60 亿美元，但在这种情况下，重点是与谷氨酸有密切关系的疾病 mGlu4 的突触前位置使其成为谷氨酸的重要贡献者。神经传递，因为谷氨酸和多巴胺从神经元的突触前位点释放 mGlu4的激活可以抑制谷氨酸和GABA等神经递质的释放，从而最近的几篇出版物提出通过直接和间接途径平衡帕金森病的神经传递。尤其是 mGlu4 作为包括 PD 在内的不同神经系统疾病的治疗靶点。研究了正变构调节剂（PAM）作为 mGlu4 的 PET 成像配体。使用药理学 MRI 方法研究开发的化合物的生物活性。我们开辟了一种表征化合物并探索其治疗用途的新方法。基于两种不同化学类型的 mGlu4 PAM 合成了 32 种不同的化合物（其中 6 种）。这些化合物已通过体内研究作为 mGlu4 的主要 PET 成像配体进行表征。我们开发的配体的局限性是快速冲洗和代谢，即使结合亲和力我们还开发了表达 mGlu4 的特定细胞系，并且细胞研究已经完成。配体表征的基础，以确定我们的结构亲和关系（SAR）实验 PAM 并确定内源性谷氨酸结合到这些方法与变构调节剂的正构结合位点和亲和力完全不同。正位配体与内源配体在同一结合位点竞争的经典方法。基于开创性工作和全世界的兴趣，我们正在寻求开发特别是氟 18 mGlu4 的标记正变构成像配体允许医学应用和分布准确地说，在目标 1 中，我们建议从 N- 合成两种 F-18 标记的先导化合物。基于苯基吡啶酰胺和噻唑并吡唑的 mGlu4 PAM 研究其成像功效、Bmax、在目标 2 中，我们将研究选择性、脑渗透性、药代动力学、代谢稳定性和其他特性。合成新系列八种含氟N-苯基吡啶酰胺衍生物和十二种氟吡啶酰胺衍生物含有用于 SAR 分析的噻唑并吡唑衍生物这项工作将得到计算的支持。将选择两种最佳化合物作为 mGlu4 的 PET 成像配体进行开发。目标 3 我们将使用 mGlu4 敲除小鼠、大鼠和灵长类动物对这些配体进行体内表征模型的最终目标是验证用于人体研究的最佳化合物并获得 IND 批准。