Allosteric and orthosteric agonists differentially activate M1 Ach receptors

变构激动剂和正构激动剂不同程度地激活 M1 Ach 受体

• 批准号: 7926925
• 负责人: Gregory Julian Digby
• 金额: $ 5.05万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7926925
• 关键词: Adverse effects; Agonist; Allosteric Site; Alzheimer' s Disease; Animal Model; Antipsychotic Agents; Arrestins; Binding Sites; Biological Assay; Brain; Calcium; Carbachol; Cell Line; Cells; Central Nervous System Diseases; Characteristics; Chemosensitization; Clinical; Cognition; Cognitive; Coupling; Data; Development; Disease; Electrophysiology (science); Event; Functional disorder; Generations; Hippocampus (Brain); Image; Learning; Life; Ligands; MAPK1 gene; Measures; Mediating; Mediator of activation protein; Memory; Modeling; Monitor; Movement; Muscarinic Acetylcholine Receptor; Muscarinics; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Parkinson Disease; Patients; Phospholipase C; Phosphorylation; Plasma Proteins; Play; Production; Proteins; Reporting; Role; Schizophrenia; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Site; Slice; Specificity; Symptoms; Testing; Therapeutic Effect; Time; base; cholinergic; combat; desensitization; imaging modality; improved; neurotransmission; novel; novel therapeutic intervention; patch clamp; receptor; release of sequestered calcium ion into cytoplasm; response; therapeutic target

DESCRIPTION (provided by applicant): A large body of evidence indicates that the Ml muscarinic acetylcholine receptors (mAChRs) play a key role in memory, learning, and control of movement. Consequently, changes in Ml levels and activity have been implicated in pathophysiology of many CNS diseases including Alzheimer's disease. Schizophrenia, and Parkinson's disease. These findings provide a rational basis for the development of novel muscarinic agents that target Ml receptors. Unfortunately, previous compounds developed to selectively activate Ml have failed in clinical development due to lack of true specificity for Ml and adverse effects associated with activation of other mAChR subtypes. To overcome this obstacle, several types of muscarinic agents that target Ml receptors through ectopic sites topographically distinct from that of the orthosteric binding site have been generated. These novel allosteric agents include ectopic agonists TBPB and VU08184670 (AK2) as well as positive allosteric modulator (PAM) VU0238386 (BQCA). Each of these compounds show exquisite subtype selectivity and thus may be novel therapeutic approaches for treatment of symptoms associated with CNS diseases. Interestingly, TBPB, VU08184670 (AK2), and VU0238386 (BQCA) may also have differential effects on different Ml-mediated signaling pathways. This type of ligand-biased agonism is a characteristic of many ligands where they preferentially stimulate a certain repertoire of a receptor's activities. The preferential activation of a subset of a receptor's responses may be beneficial for combating negative symptoms associated with CNS disorders, as they might activate certain cellular responses without activating unneeded ancillary responses. In this proposal, I will use imaging assays to measure M1- mediated generation of IP3 production and p-arrestin recruitment in real time to determine if allosteric agents differentially regulate coupling of Ml receptors to different signaling pathways. I will also use electrophysiology in brain slices to determine if allosteric agents cause persistent Ml-mediated potentiation of NMDA currents. These proposed studies will allow us to ascertain whether allosteric agents elicit unique cellular response profiles when compared to orhtosteric agonists. More importantly, they will allow us to rigorously test the hypothesis that allosteric agents induce ligand-biased signaling at Ml that may be useful for improving therapies for patients suffering from a CNS disorders such as Alzheimer's and Parkinson's disease.

描述（由申请人提供）：大量证据表明，ML毒蕈碱乙酰胆碱受体（MACHR）在记忆，学习和控制运动中起关键作用。因此，ML水平和活动的变化与包括阿尔茨海默氏病在内的许多CNS疾病的病理生理有关。精神分裂症和帕金森氏病。这些发现为靶向ML受体的新型毒蕈碱剂的发展提供了合理的基础。不幸的是，由于缺乏对ML的真实特异性和与其他MACHR亚型激活相关的不良反应，因此为选择性激活ML而开发的化合物在临床开发中已失败。为了克服这一障碍，已经产生了通过异位部位靶向ML受体的几种类型的毒蕈碱剂，从而在地形上与正常结合位点不同。这些新型的变构剂包括异位激动剂TBPB和VU08184670（AK2）以及阳性变构调节剂（PAM）VU0238386（BQCA）。这些化合物中的每一种都表现出精致的亚型选择性，因此可能是治疗与中枢神经系统疾病相关的症状的新型治疗方法。有趣的是，TBPB，VU08184670（AK2）和VU0238386（BQCA）也可能对不同ML介导的信号通路具有不同的影响。这种类型的配体偏见的激动剂是许多配体的特征，它们优先刺激受体活性的某些曲目。受体反应子集的一部分的优先激活可能有益于与中枢神经系统疾病相关的负面症状，因为它们可能会激活某些细胞反应而不会激活不需要的辅助反应。在此提案中，我将使用成像测定实时测量M1介导的IP3产生和P-arrestin募集的生成，以确定变构剂是否差异化了ML受体的偶联ML受体与不同信号通路的耦合。我还将在脑切片中使用电生理学来确定变构剂是否引起ML介导的NMDA电流增强。这些提出的研究将使我们能够确定变构剂与Orhtosteric激动剂相比是否会引起独特的细胞反应谱。更重要的是，它们将使我们能够严格检验以下假设：变构药物在ML处诱导配体有偏见的信号传导，这可能对改善患有CNS疾病的患者（例如阿尔茨海默氏病）和帕金森氏病的患者有用。