Cross-talk between the colon epithelium, colon afferents and sympathetic neurons regulate pain in the normal and inflamed colon

结肠上皮、结肠传入神经和交感神经元之间的串扰调节正常和发炎结肠的疼痛

• 批准号: 10399623
• 负责人: Kathryn Marie Albers
• 金额: $ 45.89万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-05 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10399623
• 关键词: Acute; Afferent Neurons; Biological Assay; Calcium; Calcium Signaling; Chemicals; Chronic; Colon; Colonic inflammation; Communication; Data; Disease; Electric Stimulation; Epithelial; Epithelial Cells; Fiber; Frequencies; Glutamates; Goals; Hypersensitivity; Image; Immune system; Inflammation; Inflammatory Bowel Diseases; Injury; Lead; Limb structure; Measures; Mechanics; Modeling; Motor Neurons; Mus; Nature; Neuromodulator; Neurons; Neurotransmitter Receptor; Neurotransmitters; Norepinephrine; Occupations; Opsin; Organism; Pain; Pain management; Peripheral; Peripheral Nervous System; Pharmacology; Phase; Physiological; Play; Preparation; Process; Proton Pump; Role; Serotonin; Signal Transduction; Sodium Dextran Sulfate; Spinal; Spinal Cord; Stimulus; Stress; Stretching; Sympathetic Ganglia; Symptoms; Synapses; System; Testing; Time; Visceral; Visceral pain; behavioral response; cell type; chronic pain; colorectal distension; dextran sulfate sodium induced colitis; experimental study; neuronal circuitry; novel; patch clamp; response; spinal nerve posterior root

SUMMARY Visceral pain is notoriously difficult to treat, often persisting long after the precipitating injury/disease is no longer evident. In this application we will explore a novel, multicellular peripheral circuit that we hypothesize explains many of the intractable features of chronic, visceral pain. We now know that epithelial-neuronal communication is widespread, with numerous epithelial cell types releasing neuroactive substances (e.g., ATP, ACh, 5HT, glutamate). This is particularly apparent in the colon where we have found that channelrhodopsin (ChR2) -induced activation of colon epithelial cells produces high frequency bursting of colon extrinsic primary afferent neurons (ExPAN’s), phenocopying physiologic stimuli and inducing robust behavioral responses (visceromotor responses (VMR), a validated assay of hypersensitivity). Building on these findings, new surprising data indicate colon epithelium also receives functional input from sympathetic neurons; activation of sympathetic projections to the colon induces large, phase-locked calcium signals in the epithelium. Closing the loop, we found that activation of ExPAN’s via colorectal distension (CRD) induces calcium signals in the post-ganglionic sympathetic neurons projecting to the colon, and that ChR2- induced activation of ExPAN’s induces cFos expression in these same neurons. That this multicellular circuit plays a role in visceral pain is supported further by preliminary data that shows that inflammation (acute and/or chronic) is correlated with increased signaling in all portions of this circuit. Thus, the goal of the proposed experiments is to test the hypothesis that persistent visceral hypersensitivity is due, at least in part, to amplification in an epithelial-ExPAN-sympathetic circuit such that it is possible to treat pain by breaking any limb of this feed-forward circuit (Fig.1). This hypothesis will be tested in 3 aims: Aim 1: Determine if persistent hypersensitivity induced in a model of IBD (DSS (dextran sulfate sodium)) is due to increased epithelial signaling and/or ExPAN excitability, Aim 2: Determine if DSS-induced inflammation increases the ability of ExPANs to activate sympathetic neurons in prevertebral sympathetic ganglion (PrSG) directly (via synapses in PrSG) or indirectly (via a spinal cord circuit) and, Aim 3 Determine the ability of sympathetic neurons to drive activity in epithelial cells in naïve mice and in the DSS model of IBD.

概括 众所周知，内脏疼痛很难治疗，通常在降水损伤/疾病之后持续很长时间 更长的证据。在此应用中，我们将探索一个我们假设的新型多细胞周围电路 解释了慢性内脏疼痛的许多棘手特征。 我们现在知道上皮 - 神经元通信广泛，有许多上皮细胞类型 释放神经活性物质（例如ATP，ACH，5HT，谷氨酸）。这在结肠尤其明显 我们发现通道旋丁蛋白（CHR2）诱导的结肠上皮细胞激活产生高的地方 结肠外部原发性传入神经元（EXPAN）的频率爆发，表观复习生理刺激和 诱导强大的行为反应（内脏运动反应（VMR），对超敏反应的评估）。 在这些发现的基础上，新的惊喜数据表明结肠上皮也从 同情神经元；向结肠激活交感神经项目会诱导大型的，锁定的钙 上皮中的信号。关闭循环，我们发现Expan的通过结直肠扩张（CRD）激活 诱导钙信号在投射到结肠的囊后交感神经元中，并诱导CHR2-- 诱导的EXPAN激活影响了这些相同神经元中的CFOS表达。该多细胞电路 初步数据表明注射（急性和/或 慢性）与该电路的所有部分的信号传导相关。 这是，提出的实验的目的是检验持续内脏的假设 超敏反应至少部分归因于上皮相关电路中的扩增 可以通过打破此馈送前路的任何肢体来治疗疼痛（图1）。这个假设 将在3个目标中进行测试：目标1：确定IBD模型中是否持续性超敏反应（DSS） （硫酸葡萄糖钠）））是由于上皮信号传导和/或扩展性兴奋性的增加，目标2：确定是否是否 DSS诱导的炎症会增加膨胀激活前脊椎的交感神经元的能力 直接（通过PRSG中的突触）或间接（通过脊髓电路），AIM 3 确定交感神经元在幼稚小鼠和DSS中驱动上皮细胞活性的能力 IBD的模型。