The role of RGS12 in differential modulation of G protein versus beta-arrestin signaling downstream of the kappa opioid receptor

RGS12 在 G 蛋白与 kappa 阿片受体下游 β-arrestin 信号传导的差异调节中的作用

• 批准号: 9886591
• 负责人: David P. Siderovski
• 金额: $ 38.07万
• 依托单位: UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-15 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9886591
• 关键词: Ablation; Absence of pain sensation; Acute; Affect; Agonist; American; Amphetamines; Analgesics; Anxiety; Attenuated; Automobile Driving; Autoreceptors; Behavior; Biological Assay; Central Nervous System Diseases; Chronic; Clinical; Clinical Data; Cocaine; Complement; Complex; Corpus striatum structure; Cyclic AMP; Data; Detection; Disease; Dopamine; Dopamine D2 Receptor; Drug Addiction; Excision; Exhibits; Family member; Future; G-Protein-Coupled Receptors; GTP-Binding Protein Regulators; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; Guanosine Triphosphate Phosphohydrolases; Health; Heterotrimeric GTP-Binding Proteins; Human; In Vitro; Individual; Intracellular Signaling Proteins; Knockout Mice; Locomotion; Measures; Mediating; Mental Depression; Molecular; Mouse Strains; Mus; Mutation; Nature; Neurons; Nociception; Opioid Antagonist; Opioid Receptor; Opioid agonist; Outcome; Pathway interactions; Patients; Pattern; Pertussis Toxin; Pharmaceutical Preparations; Pharmacology; Physiological Processes; Population; Protein Family; Proteins; Pruritus; RGS Proteins; Receptor Activation; Receptor Signaling; Regulation; Reporting; Research; Role; Signal Pathway; Signal Transduction; Signaling Protein; Site-Directed Mutagenesis; Spinal; Spinal Cord; Stress; Surface; Testing; Therapeutic; Validation; Ventral Striatum; addiction; base; behavioral outcome; beta-arrestin; chronic pain; chronic painful condition; clinically relevant; cost; dopamine transporter; dysphoria; in vivo; kappa opioid receptors; loss of function mutation; mRNA Expression; member; mu opioid receptors; novel; overexpression; pain relief; painful neuropathy; pre-clinical; preservation; presynaptic; protein activation; psychostimulant; public health relevance; receptor; receptor expression; receptor-mediated signaling; recruit; response; reuptake; side effect; socioeconomics; success; uptake

The kappa opioid receptor (KOR) helps mediate responses to stress, yet is also implicated in developing and/or maintaining health disorders of chronic pain, drug addiction, anxiety and depression. KOR agonists have shown promise in ameliorating these disorders, but are limited by dysphoric side effects. Beneficial effects of KOR agonists (e.g., analgesia) are considered predominantly mediated by G protein signaling, whereas β-arrestin signaling is considered central to their detrimental side effects (e.g., dysphoria). However, the mechanism(s) by which these signals downstream of KOR are regulated are still being elucidated. The Regulators of G protein Signaling are intracellular proteins that accelerate signal termination after G protein-coupled receptor activation. RGS12 is a complex member of this protein family, with at least five different domains that interact with components of both G protein-dependent and -independent signaling pathways. We recently reported that RGS12 is enriched in the ventral striatum (vSTR), and global Rgs12 ablation decreases locomotor responses to dopamine (DA)-modulating psychostimulants. Our data correlate with the augmented DA transporter (DAT) expression and function in the vSTR, but not dorsal striatum (dSTR), seen in RGS12-null mice. Loss of RGS12 (especially as a Gai/o-directed GTPase-accelerating protein) may indirectly increase DAT expression / function by removing negative regulation downstream of KOR, given that KOR agonists are known to increase DAT surface expression and uptake function. Supporting this notion, the augmented DAT function and reduced AMPH-stimulated locomotion caused by RGS12 loss are both reversed following KOR antagonism. We also found elevated KOR expression in the vSTR, but not dSTR, of RGS12-null and β-arrestin2-null mouse strains. RGS12 over-expression augments β-arrestin recruitment to activated KOR – an effect preserved following pertussis toxin-mediated Gi/o inhibition or mutation to the Ga-interacting domains of RGS12, suggesting a G protein-independent mechanism. These findings are consistent with our newest data that RGS12-null mice exhibit attenuated KOR agonist-induced conditioned place aversion, considered β-arrestin-dependent behavior. Collectively, our data highlight a role for RGS12 as a novel, differential regulator of both G protein-dependent and -independent signaling downstream of KOR activation, a regulation that may be exploitable pharmacologically to help shift KOR-mediated signaling to beneficial outcomes and away from detrimental ones. Our first aim is to determine the specific neuronal populations within which RGS12 acts to modulate G protein- dependent and -independent KOR signaling, testing hypotheses that RGS12 operates to modulate KOR and DAT function specifically in KOR- and DAT- expressing CNS neurons, and also operates at the level of the spinal cord. Our second aim is to delineate the molecular determinants that engender selective functional interactions between RGS12 and KOR. Success in pursuit of these two aims will provide key pre-clinical data for considering RGS12 a valid target for future analgesic and anti-addiction therapeutics that engage KOR signal transduction.

Kappa阿片受体（KOR）有助于调解对压力的反应，但在开发和/或 维持慢性疼痛，吸毒，焦虑和抑郁的健康障碍。 kor激动剂已经表明 有望改善这些疾病，但受烦躁的副作用的限制。 Kor的有益影响 激动剂（例如，镇痛）被认为主要是由G蛋白信号传导介导的，而β-arrestin 信号传导被认为是其有害副作用（例如吞咽困难）的核心。但是，机制 通过调节这些信号的这些信号仍在阐明。监管机构 G蛋白信号传导是细胞内蛋白，在G蛋白偶联受体后加速信号终止 激活。 RGS12是该蛋白质家族的复杂成员，至少有五个不同的域相互作用 具有G蛋白依赖性和非依赖性信号通路的成分。我们最近报道了 RGS12富含腹侧纹状体（VSTR），全局RGS12消融逐渐下降的运动反应 多巴胺（DA） - 调节心理刺激剂。我们的数据与增强的DA转运蛋白（DAT）相关 在VSTR中的表达和功能，但没有背侧纹状体（DSTR），请参见RGS12-NULL小鼠中的表达和功能。 RGS12的损失 （特别是作为GAI / O指导的GTPase加速蛋白）可能会间接增加DAT表达 /功能 鉴于众所周知，Kor Agonists会增加DAT 表面表达和吸收功能。支持此概念，增强的DAT功能并降低 在Kor拮抗作用后，由RGS12损失引起的AMPH刺激的运动均逆转。我们也是 发现RGS12-NULL和β-arrestin2-null小鼠菌株的VSTR中的Kor表达升高，但没有DSTR。 RGS12过表达增强β-arrestin募集到激活的kor - 这是保留的效果。 百日咳毒素介导的GI/O抑制作用或对RGS12的GA相互作用域的突变，表明A G蛋白非依赖性机制。这些发现与我们的最新数据一致RGS12-NULL小鼠 呼气减弱了kor激动剂引起的条件厌恶，被认为是β-arrestin依赖性行为。 总的来说，我们的数据突出了RGS12作为G蛋白依赖性的新型差异调节剂的作用 和 - 非依赖性信号传导下游的kor激活，该法规可能是可利用的 在药理上，有助于将KOR介导的信号转移到有益结果，并远离有害结果。 我们的第一个目的是确定RGS12调节G蛋白的特定神经元种群。 依赖性和独立的KOR信号传导，测试RGS12可调节Kor和的假设 DAT功能专门在kor和Dat-表达CNS神经元中，并且在脊柱的水平上运行 绳索。我们的第二个目的是描述产生选择性功能相互作用的分子决定素 在RGS12和Kor之间。追求这两个目标的成功将提供关键的临床前数据 RGS12一个有效的镇痛和抗添加疗法的有效靶标，可吸引KOR信号转导。