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Using Human iPSC Models to Determine the Mechanism of Inflammation-Induced Disruption of Dopamine Neurotransmission

使用人类 iPSC 模型确定炎症引起的多巴胺神经传递中断的机制

基本信息

批准号：
10575155
负责人：
ANDREW H MILLER
金额：
$ 23.48万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-20 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10575155
关键词：
Address Affect Affinity Alternative Splicing Anhedonia Behavior Biochemistry Blood - brain barrier anatomy Brain Brain region Corpus striatum structure DRD2 gene Data Dopamine Dopamine D2 Receptor Drug Targeting Electrophysiology (science)Exocytosis FDA approved Gene Expression Genetic Risk Goals Human Image Immune Immunofluorescence Immunologic In Vitro Inflammation Inflammation Mediators Inflammatory Interferon-alpha Interleukin 6 Receptor Interleukin-6 JAK1 gene Knowledge Laboratory Animals Life Cycle Stages Light Major Depressive Disorder Measures Mediating Mental Depression Mental disorders Microdialysis Modeling Molecular Molecular Profiling Motivation Names Neurons Neurotransmitters Pathogenicity Pathway interactions Peripheral Pharmaceutical Preparations Play Population Heterogeneity Predisposition Protein Isoforms Proton Pump RNA Splicing Research Resolution Rodent Role Schizophrenia Signal Transduction Signaling Molecule Symptoms Synapses Synaptic Membranes Synaptic Transmission Synaptic Vesicles Testing Toxic effect Untranslated RNA Variant Ventral Striatum Vesicle biomarker discovery brain behavior cohort cytokine depressed patient depressive symptoms design disability disabling symptom dopamine system dopaminergic neuron drug development drug discovery experimental study extracellular gene product gene repression genetic analysis in vivo induced pluripotent stem cell inhibitor innovation interdisciplinary approach neural circuit neuroimaging neurotransmission neurotransmitter release nonhuman primate novel therapeutics presynaptic relating to nervous system response reuptake reward circuitry risk variant stem cell model stem cell technology trafficking transcriptomics vacuolar H+-ATPase vesicle transport vesicular monoamine transporter 2 vesicular release

项目摘要

PROJECT SUMMARY The current proposal will use innovative stem cell technology to explore the mechanism(s) by which inflammation affects dopamine (DA) neurotransmission, with a special focus on inflammation's effects on presynaptic DA vesicles. Inflammation is believed to play a pivotal pathophysiologic role in ~30% of depressed patients and is associated with effects on reward circuitry, leading to motivational deficits and ultimately anhedonia. Anhedonia is a core and disabling symptom of depression, which is the leading cause of disability worldwide. Studies in laboratory animals and humans indicate that one of the major targets of inflammation in the brain is DA in the ventral striatum, a subcortical brain region that has been shown to be uniquely accessible to peripheral inflammatory mediators including interleukin (IL)-6 through disruption in the blood brain barrier. In vivo microdialysis in non-human primates and rodents demonstrate that administration of inflammatory cytokines including IL-6 reduces extracellular DA availability and release, and neuroimaging studies in humans demonstrate reduced striatal DA turnover following administration of the inflammatory cytokine interferon-alpha. What remains unknown, however, are the specific cellular and molecular mechanisms by which inflammatory cytokines such as IL-6 disrupt DA neurotransmission. Our preliminary findings indicate that in vitro IL-6 treatment of human induced pluripotent stem cell (hiPSC)-derived DA neurons (which express IL-6 receptors) directly decreases DA availability and downregulates gene expression in pathways associated with synaptic vesicular function. These effects occurred in the absence of cellular toxicity, and the gene expression changes were reversed by baricitinib, an FDA-approved drug that was developed at Emory and blocks IL-6 signaling through inhibition of Janus Kinases 1 and 2. In the current project, we aim to further elucidate the mechanisms by which IL-6 affects DA neurotransmission using human iPSC-derived DA neurons. Specifically, we will determine the impact of IL-6 on synaptic vesicular function in the presence or absence of baricitinib in hiPSC-derived DA neurons (Aim 1). We will further determine the impact of IL-6 on alternative splicing of the DRD2 gene, which in turn can regulate synaptic vesicular function in DA neurons (Aim 2). These studies will also include DA neurons expressing the depression-associated DRD2 variant rs1076560, which is associated with alternate DRD2 splicing. Taken together, the proposed experiments will provide an important proof of principle for the use of stem cell technology to reveal the mechanisms of inflammation's effects on DA neurotransmission, shedding new light on pathogenic mechanisms underlying DA system deficits in psychiatric disorders, while providing a platform for drug development aligned with Emory's drug discovery pipeline.

项目概要目前的提案将使用创新的干细胞技术来探索炎症的机制影响多巴胺 (DA) 神经传递，特别关注炎症对突触前 DA 的影响囊泡。据信，炎症在大约 30% 的抑郁症患者中发挥着关键的病理生理作用，并且与奖励回路的影响有关，导致动机缺陷并最终导致快感缺乏。快感缺失是抑郁症的核心和致残症状，是全世界致残的主要原因。研究于实验动物和人类表明，大脑炎症的主要目标之一是 DA 腹侧纹状体，一个皮层下的大脑区域，已被证明是外周细胞唯一可访问的区域通过破坏血脑屏障来抑制包括白细胞介素 (IL)-6 在内的炎症介质。体内非人类灵长类动物和啮齿类动物的微透析表明，炎症细胞因子的施用包括 IL-6 会降低细胞外 DA 的可用性和释放，以及人类神经影像学研究证明给予炎性细胞因子干扰素-α后纹状体 DA 周转减少。然而，目前尚不清楚的是炎症发生的具体细胞和分子机制。 IL-6 等细胞因子会破坏 DA 神经传递。我们的初步研究结果表明，体外 IL-6 治疗直接源自人类诱导多能干细胞 (hiPSC) 的 DA 神经元（表达 IL-6 受体）降低 DA 可用性并下调突触小泡相关通路中的基因表达功能。这些效应是在没有细胞毒性的情况下发生的，并且基因表达的变化是 baricitinib 可以逆转这种情况，baricitinib 是 FDA 批准的药物，由埃默里大学开发，通过阻断 IL-6 信号传导 Janus 激酶 1 和 2 的抑制。在当前的项目中，我们的目标是进一步阐明其机制 IL-6 使用人类 iPSC 衍生的 DA 神经元影响 DA 神经传递。具体来说，我们将确定在 hiPSC 衍生的 DA 中存在或不存在巴瑞替尼的情况下 IL-6 对突触小泡功能的影响神经元（目标 1）。我们将进一步确定 IL-6 对 DRD2 基因选择性剪接的影响，这在转可以调节 DA 神经元的突触小泡功能（目标 2）。这些研究还将包括 DA 神经元表达与抑郁症相关的 DRD2 变体 rs1076560，该变体与替代 DRD2 相关拼接。总而言之，所提出的实验将为使用干细胞技术揭示炎症对 DA 神经传递、脱落影响的机制对精神疾病中 DA 系统缺陷的致病机制有了新的认识，同时提供了与埃默里大学的药物发现管道保持一致的药物开发平台。