Sensory Cross-Activation in Bowel Dysfunction

肠功能障碍中的感觉交叉激活

• 批准号: 10533810
• 负责人: Liya Qiao
• 金额: $ 48.36万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-15 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10533810
• 关键词: Adverse effects; Afferent Neurons; Affinity; Affinity Chromatography; Animal Model; Animals; Axon; Bladder; Blood - brain barrier anatomy; Brain-Derived Neurotrophic Factor; Calcitonin Gene-Related Peptide; Calcium; Cells; Central Nervous System; Chief Cell; Clozapine; Coculture Techniques; Colon; Data; Development; Disease; Event; Functional disorder; Ganglia; Gender; Generations; Genetic; Genetic Transcription; Genotype; Goals; Human; Hyperactivity; Hypersensitivity; In Vitro; Inflammation; Inflammatory Bowel Diseases; Intestines; Ion Channel; Irritable Bowel Syndrome; Measures; Mechanics; Mediating; Mediator; Messenger RNA; Modality; Molecular; Mus; N-Methyl-D-Aspartate Receptors; Nerve; Neuroglia; Neurons; Neuropeptides; Neurotrophic Tyrosine Kinase Receptor Type 2; Organ; Oxides; Pain; Pathway interactions; Patients; Peripheral; Permeability; Pharmaceutical Preparations; Process; Proteins; Proteolipids; Proteomics; Regulation; Role; Sensory; Spinal; Spinal Cord; Spinal Ganglia; System; Testing; Tissues; Vertebral column; Visceral; central sensitization; clinically relevant; comorbidity; designer receptors exclusively activated by designer drugs; experience; experimental study; glial activation; in vivo; insight; neurochemistry; novel; pain processing; paracrine; remote location; screening; sexual dimorphism; side effect; therapeutic development; therapeutic target

PROJECT SUMMARY It is a common occurrence in human that pain is perceived at a remote location away from the diseased organ. This is also true with bowel dysfunction. Patients with inflammatory bowel diseases (IBD) and/or irritable bowel syndrome (IBS) often experience bladder hyperactivity and somatic pain. Understanding the peripheral mechanisms of pain generation and sensory cross-sensitization helps development of therapeutic approaches with minimum central adverse effects to treat pain comorbidity. Peripheral glial cells are gaining increased recognition for their roles in modulating sensory neuron activity. Satellite glial cells (SGCs) of dorsal root ganglia (DRG) reside around sensory neurons and connect sensory neurons through SGC networks. Using Cre-based expression of hM3Dq to activate glial cells by clozapine-N-oxide (CNO), we show that activation of glial cells leads to an enhanced calcitonin gene-related peptide (CGRP) release to the spinal cord, an essential process in spinal central sensitization. Activation of glial cells also facilitates hypersensitivity of the colon, urinary bladder and hind paw in mice. In DRG, TrkB.T1 is expressed by SGCs but not neurons. Calcium (Ca2+) activity is a common pathway mediated by hM3Dq and TrkB.T1 in SGCs. Importantly, using a unique SGC- sensory neuron co-culture system we show that activation of SGCs mediated by TrkB.T1 leads to activation of adjacent sensory neurons that participate in pain processing. We therefore hypothesize that TrkB.T1 mediates glia-neuron interaction and participates in sensory neuron cross-activation and cross-organ sensitization. To test this hypothesis, we will use mice with inducible conditional TrkB.T1 deletion (TrkB.T1cKO) from peripheral glia mainly from SGCs and mice with hM3Dq or hM4Di expression in peripheral glia. We will perform molecular and functional analysis of colon-bladder sensory neuron cross-activation and cross-organ sensitization in these unique mouse lines (Aim 1). The functional roles of TrkB.T1 in SGCs are to increase the levels of Ca2+ to promote gliotransmitter release. We have identified a number of glial mediators that are regulated by TrkB.T1 in SGCs through proteomic screening and transcriptional analysis. We will characterize TrkB.T1-mediated gliotransmission and gliotransmitter-facilitated sensory neuron activation in the context of cross-organ sensitization (Aim 2). Central sensitization not only contributes to colon-bladder cross-sensitization but also underlies viscero-somatic cross-sensitization. We therefore will examine whether TrkB.T1-mediated SGC- sensory neuron crosstalk contributes to CGRP central release and leads to viscero-somatic cross-sensitization (Aim 3). Throughout the three aims, we will use more than one animal models and apply in vivo and in vitro approaches for functional and mechanistic studies. Interestingly, our preliminary data show that TrkB.T1 is sexually dimorphic. We therefore will perform our experiments in both genders. We anticipate revealing the role of TrkB.T1 in glia-neuron interaction to provide insights in understanding the development of cross-organ sensitization and suggest therapeutic targets.

项目摘要 人类很常见的情况是，在远离患病的偏远位置会感知疼痛 器官。肠功能障碍也是如此。炎症性肠病（IBD）和/或易怒的患者 肠综合征（IBS）经常经历膀胱多动症和躯体疼痛。了解外围 疼痛产生和感觉交叉敏化的机制有助于发展治疗方法 具有最小的中心不良反应来治疗疼痛合并症。外围神经胶质细胞的增加增加 识别其在调节感觉神经元活性的作用。背根的卫星神经胶质细胞（SGC） 神经节（DRG）围绕感官神经元，并通过SGC网络连接感觉神经元。使用 基于CRE的HM3DQ表达通过氯氮平-N-氧化物（CNO）激活神经胶质细胞，我们表明激活的激活 神经胶质细胞导致降钙素基因相关肽（CGRP）释放到脊髓，这是必不可少的 脊柱中央敏化的过程。神经胶质细胞的激活还促进了结肠的超敏反应， 小鼠的膀胱膀胱和后爪。在DRG中，TRKB.T1由SGC表示，而不是神经元表达。钙（CA2+） 活性是SGC中HM3DQ和TRKB.T1介导的常见途径。重要的是，使用独特的SGC- 感觉神经元共培养系统我们表明，由TRKB.T1介导的SGC的激活导致激活 参与疼痛处理的邻近感觉神经元。因此，我们假设trkb.t1介导 胶质神经元的相互作用并参与感觉神经元交叉激活和跨器官敏化。到 检验此假设，我们将使用外围的有条件trkb.t1删除（trkb.t1cko）使用小鼠 GliA主要来自外周神经胶质中的SGC和HM3DQ或HM4DI表达的小鼠。我们将执行分子 在这些中，结肠叶片的感觉神经元交叉激活和跨器官敏化的功能分析 独特的鼠标线（AIM 1）。 trkb.t1在SGC中的功能作用是将Ca2+的水平提高到 促进胶质递升释放。我们已经确定了许多受TRKB.T1调节的神经胶质介质 通过蛋白质组学筛选和转录分析在SGC中。我们将表征trkb.t1介导的 在跨器官的背景下 灵敏度（目标2）。中央敏化不仅有助于结肠叶片交叉敏感性，而且有助于 基础内脏跨敏化。因此，我们将检查TRKB.T1介导的SGC-是否 感觉神经元串扰有助于CGRP中心释放，并导致内脏跨敏化 （目标3）。在这三个目标中，我们将使用多个动物模型，并在体内和体外应用 功能和机械研究的方法。有趣的是，我们的初步数据表明trkb.t1是 性二态。因此，我们将在两个性别中进行实验。我们预计会揭示 trkb.t1在胶质神经元相互作用中的作用，以提供理解跨器官发展的见解 敏化并提出治疗靶标。