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

• 批准号: 10707196
• 负责人: ANDREW H MILLER
• 金额: $ 19.56万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 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/10707196
• 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; Experimental Designs; 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; 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; Proton-Translocating ATPases; 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; cohort; cytokine; depressed patient; depressive symptoms; 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; neural circuit; neuroimaging; neurotransmission; neurotransmitter release; nonhuman primate; novel therapeutics; presynaptic; response; reuptake; reward circuitry; risk variant; stem cell model; stem cell technology; technology platform; trafficking; transcriptomics; vesicle transport; vesicular monoamine transporter 2; vesicular release

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.

项目摘要 当前的建议将使用创新的干细胞技术探索炎症的机制 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。据信炎症在约30％的抑郁症患者中起关键的病理生理作用，并且 与对奖励电路的影响相关，导致动机赤字和最终的Anhedonia。阿内多尼亚 是抑郁症的核心和残疾症状，这是全球残疾的主要原因。研究 实验室动物和人类表明，大脑炎症的主要靶标之一是DA 腹侧纹状体，皮层下脑区域，已被证明是独特的。 通过血液脑屏障的破坏，包括白介素（IL）-6在内的炎症介体。体内 非人类灵长类动物和啮齿动物中的微透析表明炎症细胞因子的给药 包括IL-6降低了细胞外DA的可用性和释放，以及人类的神经影像学研究 在炎症性细胞因子干扰素α进行后，证明纹状体DA的周转率降低。 然而，未知的是炎症的特定细胞和分子机制 IL-6等细胞因子破坏DA神经传递。我们的初步发现表明体外IL-6治疗 人类诱导的多能干细胞（HIPSC）衍生的DA神经元（表达IL-6受体）的 降低DA的可用性并下调与突触囊泡相关的途径中的基因表达 功能。这些作用发生在没有细胞毒性的情况下，基因表达的变化是 由Bariticinib逆转，Baricitinib是一种在Emory开发的FDA批准的药物，并阻止IL-6信号传导 抑制Janus激酶1和2。在当前项目中，我们旨在进一步阐明其机制 IL-6使用人IPSC衍生的DA神经元影响DA神经传递。具体来说，我们将确定 IL-6在hipsc衍生的da中存在或不存在bariticinib的情况下对突触囊泡功能的影响 神经元（目标1）。我们将进一步确定IL-6对DRD2基因的替代剪接的影响，该基因在 转弯可以调节DA神经元中的突触囊泡功能（AIM 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，这与替代DRD2相关 剪接。综上所述，拟议的实验将为使用的重要原则证明 干细胞技术揭示了炎症对DA神经传递的影响的机制 关于精神疾病中DA系统缺陷的致病机制的新灯，同时提供 药物开发平台与Emory的药物发现管道保持一致。