Targeting of Alpha7 nAChR for therapeutic effects

靶向 Alpha7 nAChR 以获得治疗效果

基本信息

批准号：
10331721
负责人：
ROGER L PAPKE
金额：
$ 45.68万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-05-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10331721
关键词：
Acute Agonist Allosteric Site Alzheimer&apos s Disease Amines Ammonium Animal Model Anti-Cholinergics Anti-Inflammatory Agents Arthritis Asthma Binding Binding Sites Biochemical Biological Biological Assay Brain Cells Central Nervous System Diseases Charge Choline Chronic inflammatory pain Cognition Cognition Disorders Cognitive Conotoxin Data Disease Dose Drug Kinetics Electrophysiology (science)Family Female GTS-21 Hyperalgesia Immune system In Vitro Inflammation Inflammatory Injury Ion Channel Leukocytes Ligand Binding Ligands Measures Mechanics Mediating Mediator of activation protein Medicine Microglia Microscopic Modeling Molecular Molecular Conformation Motivation Mus Neuroglia Neurons Neuropathy Neurotransmitters New Agents Nicotine Nicotinic Receptors Nitrogen Oral Administration Output Pain Pathway interactions Penetration Peripheral Pharmaceutical Preparations Pharmacology Phase Process Production Property Proteins Regulation Schizophrenia Sepsis Series Signal Transduction Site Structure-Activity Relationship Sulfonium Compounds Testing Therapeutic Therapeutic Effect Thromboplastin Time Tissues Work allodynia alpha-bungarotoxin receptor base cell type chronic constriction injury chronic neuropathic pain chronic pain conditioned place preference cytokine desensitization design effectiveness testing experience extracellular gene product improved in vivo in vivo Model in vivo evaluation inflammatory pain male mutant neuroinflammation novel novel drug class pain model pain reduction painful neuropathy pharmacophore positive allosteric modulator prototype receptor receptor function response scaffold screening therapeutic target

项目摘要

The nicotinic acetylcholine receptor (nAChR) a7 subtype has numerous properties that distinguish it from other nAChRs, including activation by both the neurotransmitter ACh and the ubiquitous tissue factor choline, a feature that may be associated with its important functional expression in both neuronal and non-neuronal cells, including cells of the immune system. Expressed in such diverse tissues, a7 nAChR are also recognized as potentially important therapeutic targets for diverse indications including CNS disorders like Alzheimer's disease and schizophrenia, as well as peripheral disorders, especially inflammatory diseases and pain. Traditionally, study of a7 and other nAChRs has focused on ligands that activate or antagonize the receptor's ion channel; however, it has recently been shown that the best drugs for treating the peripheral disorders through the cholinergic anti-inflammatory pathway (CAP) may preferentially induce the alternative conformational states associated with ion channel desensitization. Consistent with the hypothesis that the selective targeting of a7 receptors for peripheral disorders requires qualitatively different drugs from those for CNS disorders, cells that mediate a7 control of inflammation do not have a7 receptors with activatible ion channels, possibly due to the co-expression of other gene products that limit ion channel function and confer distinct pharmacological profiles for a7 function in those cells. We have used electrophysiological, biochemical, and molecular biological approaches to determine how the multiple conformational states of a7 are selectively regulated by ligands, and we have used positive allosteric modulators (PAMs) to identify novel molecules that we characterized as silent agonists. These silent agonists are weak partial agonists in regards to channel activation but effective activators of CAP. Additionally, our studies of allosteric activators (ago- PAMs) and mutant receptors that cannot be activated by ACh or other orthosteric agonists has led to the identification of an allosteric agonist binding site and a new class of ligands that are PAM-dependent channel activators that also activate CAP. One aim will be to further characterize allosteric activators working with the structural scaffolds that we have identified, which include both potent small ligands and MrIC conotoxin. The conotoxin and mutants thereof will provide a template for the design of additional small ligands. We will also develop new ligands based on a novel sulfonium-based agonist that lacks a charged nitrogen and should have good brain penetration for indications of neuro-inflammatory pain and disease. We will test our new ligands and previously identified reference compounds in cell-based assays for the regulation of cytokine production and mediators of signal transduction that are relevant to inflammatory disease and pain. Data on the reference compounds will help define a target profile for new compounds. New compounds with desired cytokine profiles and good predicted pharmacokinetic properties will be moved forward into animal models of neuropathic and inflammatory pain. We will also test hypotheses related to accessory proteins that may differentially regulate a7 function in different cell types. We will then directly evaluate their efficacy in vivo for reducing pain from inflammation. These studies will allow us to test our core hypothesis that the therapeutic targeting of a7 for specific indications relies on identifying ligands that discriminate between channel-dependent and channel- independent signaling modes.

烟碱乙酰胆碱受体（NACHR）A7亚型具有许多区别于其他特性 NACHR，包括神经递质ACH和无处不在的组织因子胆碱的激活，A 可能与其在神经元和非神经元中的重要功能表达相关的功能细胞，包括免疫系统的细胞。在如此多样化的组织中，A7 NACHR也被识别作为包括CNS疾病（如阿尔茨海默氏症）的不同指示的潜在重要治疗靶标疾病和精神分裂症，以及周围疾病，尤其是炎症性疾病和疼痛。传统上，对A7和其他NACHR的研究集中在激活或拮抗受体的配体上离子通道；但是，最近已经显示出治疗周围疾病的最佳药物通过胆碱能抗炎途径（CAP）可以优先引起替代方案与离子通道脱敏相关的构象状态。与假设一致 A7受体的选择性靶向外周疾病需要与药物不同的药物。 CNS疾病，介导A7控制炎症的细胞没有具有活化离子的A7受体通道，可能是由于其他基因产物的共表达，这些基因产物限制了离子通道函数并授予这些细胞中A7功能的不同药理谱。我们使用了电生理学，生化和分子生物学方法来确定A7多构象状态如何由配体选择性调节，我们使用阳性变构调节剂（PAM）来识别新颖我们将其描述为沉默激动剂的分子。这些沉默的激动剂是弱的局部激动剂。引导激活但有效的CAP激活剂。此外，我们对变构激活剂的研究（AGO- PAMS）和无法被ACH或其他直角激动剂激活的突变受体已导致鉴定变构激动剂结合位点和新的依赖PAM依赖性通道的配体激活帽的激活器。一个目的是进一步表征与我们已经鉴定出的结构支架，包括有效的小配体和MRIC结合毒素。这结合毒素及其突变体将为设计其他小配体设计模板。我们也会基于缺乏带电的氮的新型激动剂开发新的配体，应具有良好的脑穿透性，以表明神经炎症性疼痛和疾病的适应症。我们将测试我们的新配体并以前鉴定的基于细胞的调节细胞因子产生的参考化合物以及与炎症性疾病和疼痛有关的信号转导介体。参考数据化合物将有助于定义新化合物的目标配置文件。带有所需细胞因子曲线的新化合物良好的预测药代动力学特性将转移到神经性动物模型和炎症性疼痛。我们还将测试与辅助蛋白有关的假设，这些假设可能会差异调节 A7在不同的单元格中功能。然后，我们将直接评估它们在体内减轻疼痛的疗效炎。这些研究将使我们能够检验我们的核心假设，即A7的治疗靶向具体的指示依赖于识别区分依赖通道和通道的配体独立的信号模式。