Synaptic mechanisms underlying the rapid antidepressant properties of the (2R,6R)-hydroxynorketamine metabolite

(2R,6R)-羟基去甲氯胺酮代谢物快速抗抑郁特性的突触机制

• 批准号: 10227667
• 负责人: Lace Marie Riggs
• 金额: $ 1.81万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2022-01-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10227667
• 关键词: Acids; Acute; Adenosine Triphosphate; Adenylate Cyclase; Adverse effects; Affinity; Anesthetics; Antidepressive Agents; Autoreceptors; Bathing; Behavior; Behavioral; Biochemistry; Brain-Derived Neurotrophic Factor; Calcium; Calcium Channel; Cells; Chemosensitization; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Development; Dose; Electrophysiology (science); Fiber; Glutamates; Hippocampus (Brain); Immunohistochemistry; Impairment; In Vitro; Ketamine; Lead; Learning; Long-Term Potentiation; Major Depressive Disorder; Mediating; Mental Depression; N-Methyl-D-Aspartate Receptors; Pathway interactions; Patients; Performance; Pharmacotherapy; Phosphorylation; Photometry; Probability; Process; Production; Property; Protein Kinase; Proteins; Resistance; Risk; Role; Self-Injurious Behavior; Signal Transduction; Slice; Substance abuse problem; Suicide; Synapses; Synapsins; Synaptic Transmission; Testing; Therapeutic; Toxicology; Western Blotting; Work; clinical practice; coping; experimental study; extracellular; improved; in vivo; neuropsychopharmacology; neurotransmitter release; novel; postsynaptic; pre-clinical; presynaptic; receptor; reduce symptoms; symptom treatment; treatment-resistant depression

PROJECT SUMMARY There has been a need to improve depression pharmacotherapies for several decades. Despite this, new treatment advances have been slow to progress, or have failed to reach clinical practice. Perhaps the most impactful advance, has been the discovery that subanesthetic ketamine can rapidly alleviate treatment- resistant major depression. While it is known that ketamine exerts its anesthetic effects through N-methyl-D- aspartate receptor (NMDAR) antagonism, it is unclear as to whether this is its antidepressant mechanism of action. Our lab has previously shown that ketamine is rapidly converted into various metabolites, and at least one of these, (2R,6R)-hydroxynorketamine (HNK), retains the rapid antidepressant-like preclinical properties of ketamine, but lacks its adverse effects given its low affinity to inhibit the NMDAR. My data reveal that (2R,6R)- HNK promotes a rapid potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- mediated synaptic transmission, through a concentration-dependent, NMDAR-independent, and synapse- selective increase in glutamate release probability at Schaffer collateral (SC)-CA1 synapses (Riggs et al., 2019, Neuropsychopharmacology). My preliminary data suggest that the presynaptic effects of (2R,6R)-HNK require protein kinase activity, and presynaptic calcium channel influx. Consistent with this, studies have shown that (2R,6R)-HNK leads to a rapid accumulation of intracellular cyclic adenosine monophosphate (cAMP), which converges with the actions of locally elevated calcium to regulate protein kinase activity. Additionally, the behavioral effects of (2R,6R)-HNK converge with a mechanism downstream of presynaptic glutamate auto- receptors that inhibit the production of cAMP, whereas cAMP triggers the release of brain-derived neurotrophic factor (BDNF), which is also required for (2R,6R)-HNK to exert its behavioral effects. Thus, I hypothesize that (2R,6R)-HNK exerts its rapid synaptic potentiation through an acute increase in cAMP-dependent, presynaptic BDNF-TrkB signaling. I will test this hypothesis with three specific aims, using both ex vivo and in vivo approaches. First, I will use acute slice electrophysiology to determine whether the presynaptic effects of (2R,6R)-HNK are cAMP-dependent, and engages its downstream target, protein kinase A (PKA). Using biochemistry, I will verify changes in post-recording presynaptic cAMP, as well as phosphorylation changes in proteins downstream of PKA, known to actively participate in glutamate release. Second, I will test the role of BDNF-TrkB signaling in the presynaptic actions of (2R,6R)-HNK, and assess phosphorylation changes in TrkB and its presynaptic downstream targets. Lastly, I will use in vivo fiber photometry to determine if (2R,6R)-HNK improves learning in a SC-CA1-dependent task by increasing the strength of synaptic transmission at SC-CA1 synapses in a BDNF-dependent manner. My experiments will test the role of presynaptic signal transduction in the acute mechanism of action of (2R,6R)-HNK, which will advance our understanding of how presynaptic plasticity gives rise to sustained adaptations in synaptic transmission and behavior.

项目摘要 几十年来，有必要改善抑郁症的药物治疗。尽管如此，新的 治疗进展的进展缓慢，或者未能达到临床实践。也许最多 有影响力的进步一直是，氯胺酮可以迅速减轻治疗 - 抵抗重大抑郁症。众所周知，氯胺酮通过N-甲基-D-执行麻醉作用 天冬氨酸接收器（NMDAR）拮抗作用，目前尚不清楚这是否是其抗抑郁机制 行动。我们的实验室以前已经表明，氯胺酮迅速转化为各种代谢物，至少是 其中之一（2R，6R） - 羟基诺甲胺（HNK）保留了快速的抗抑郁药样临床前性能 氯胺酮，但由于其低亲和力抑制NMDAR，但缺乏其不良影响。我的数据表明（2R，6R） - HNK促进了α-氨基-3-羟基-5-甲基-4-异沙唑丙酸受体（AMPAR）的快速增强 - 通过浓度依赖性，独立于NMDAR和突触的介导的突触传播 Schaffer抵押品（SC）-CA1突触的谷氨酸释放概率的选择性增加（Riggs等，2019， 神经心理药理学）。我的初步数据表明（2R，6R）-HNK的突触前作用需要 蛋白激酶活性和突触前钙通道影响。与此一致，研究表明 （2R，6R）-HHNK导致细胞内循环腺苷一磷酸（CAMP）的迅速积累 与局部升高钙调节蛋白激酶活性的作用收敛。另外， （2R，6R）-HHNK的行为影响与突触前谷氨酸自动 - 抑制营地产生的受体，而营地触发了脑衍生的神经营养的释放 因子（BDNF），（2R，6R）-HHNK也需要执行其行为效应。那我假设 （2R，6R）-HHNK通过急剧依赖camp依赖性的急性增加，发挥其快速突触电位 突触前BDNF-TRKB信号传导。我将使用离体和 体内方法。首先，我将使用急性切片电生理学来确定突触前作用是否效果 （2R，6R）-HHNK的依赖性camp依赖性，并参与其下游靶标，蛋白激酶A（PKA）。使用 生物化学，我将验证录制后突触前营地的变化，以及磷酸化的变化 PKA下游的蛋白质，已知会积极参与谷氨酸释放。其次，我将测试 （2R，6R）-HNK的突触前作用中的BDNF-TRKB信号传导和TRKB的评估磷酸化变化 及其突触前的下游靶标。最后，我将使用体内纤维光度法来确定（2R，6R）-HNK是否是否 通过增加SC-CA1的突触传播的强度来改善SC-CA1依赖性任务中的学习 以BDNF依赖性方式突触。我的实验将测试突触前信号转导的作用 （2R，6R）-HNK的急性作用机理，这将提高我们对突触前的理解 可塑性导致突触传播和行为的持续适应。