Orexin Signaling in the Mouse Cochlea

小鼠耳蜗中的食欲素信号传导

• 批准号: 10598992
• 负责人: DOUGLAS E VETTER
• 金额: $ 23.25万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10598992
• 关键词: AMPA Receptors; Ablation; Adenylate Cyclase; Adult; Anxiety; Attenuated; Behavior; Brain; Cells; Cochlea; Code; Cyclic AMP-Dependent Protein Kinases; Data; Drug usage; Exposure to; Family; Feeding behaviors; Fiber; Functional disorder; Genes; Genetic; Glutamate Receptor; Glutamates; Goals; Growth; Hair Cells; Health; Hearing; Hypothalamic structure; Immune; Immune response; Immunohistochemistry; Individual; Infarction; Inflammation; Inflammatory; Inflammatory Response; Investigation; Ion Channel; Knockout Mice; Knowledge; Ligands; Link; Macrophage; Maintenance; Marketing; Mediating; Metabolic; Mind; Morphology; Mus; Narcolepsy; Nerve Fibers; Neurons; Neuropeptides; Noise; Noise-Induced Hearing Loss; Pain; Pathway interactions; Patients; Peptides; Peripheral; Persons; Pharmaceutical Preparations; Pharmacologic Substance; Physiological; Play; Population; Post-Traumatic Stress Disorders; Predisposition; Process; Proto-Oncogene Proteins c-akt; Pruritus; Recovery; Regulation; Reporting; Research; Risk; Role; Safety; Shapes; Signal Pathway; Signal Transduction; Sleep; Sleep Wake Cycle; Sleeplessness; Spinal Cord; Stains; Stroke; Supporting Cell; Symptoms; Synapses; System; Techniques; Time; Tissues; Wild Type Mouse; Work; age related; aged; antagonist; auditory stimulus; chemokine; cholinergic; cytokine; dorsal horn; drug clearance; experience; genetic manipulation; hearing impairment; hypocretin; immune cell infiltrate; immunoregulation; neural; neurotransmission; neurotransmitter release; noise exposure; novel; null mutation; orexin A; orexin B; permanent hearing loss; postsynaptic; preprohormone; protein expression; receptor; receptor expression; response; sleep abnormalities; sleep pattern; sound; theories; trafficking

The research undertaken for this proposal is significant because it represents the first investigation of the role of Orexin signaling in the cochlea and as such, will result in novel basic knowledge of a new signaling pathway related to cochlear function. We will also define potential safety concerns regarding impacts to hearing health associated with the use of an insomnia drug that is already used by a significant portion of the US population. The Orexins are a family of two peptides that in the brain are exclusively expressed in hypothalamic neurons. Both Orexin receptors, however, are widely dispersed throughout the brain. Defective Orexin signaling has been linked to sporadic nonfamilial narcolepsy, the most common form of narcolepsy, and therefore most research on Orexin signaling targets sleep/wake behavior. Using immunohistochemistry, we show that the Orexin pre-prohormone, both mature Orexins peptides, and their receptors are expressed in the cochlea. We demonstrate that Orexin A/B pre-prohormone gene null mice (thus lacking all Orexin ligands) do not recover ABR thresholds following noise exposures that induce classic TTS in wild type mice. This is a translationally significant finding because Ox1R and Ox2R are targets of Orexin receptor antagonist pharmaceuticals such as Suvorexant (Belsomra®) marketed to treat insomnia. Approximately 30% of adults in the US report symptoms of insomnia and 4% reported prescription sleep aid use in the month prior to a 2013 CDC poll. While sleep aids are meant for brief duration use, they are often used for long periods of time (months to years). This is especially true of aged individuals and those suffering from any of numerous other conditions (PTSD, anxiety, etc.). A major question is whether a latent risk exists in using Orexin-targeting insomnia medications- do these drugs leave patients at risk for hearing dysfunction, especially if taken consistently over time that would result in incomplete clearance of the drug? This work is further translationally relevant because sleep aids are often used by older individuals, who as a population suffer from abnormal sleep patterns/insomnia and also typically are experiencing normal age-related hearing dysfunction. Our goal for this project is to: 1) verify and expand our preliminary data obtained with Orexin ligand nulls by demonstrating which receptor (Ox1R , Ox2R, or both) contribute to the loss of hearing following moderate-level sound exposures; and 2) begin an assessment of the mechanisms underlying the observed dysfunction associated with loss of Orexin signaling. We will use a combination of morphological (immunostaining for afferent synapses under IHCs), physiological (ABRs and DPs), and protein expression (cytokine arrays) analyses to investigate the role of Orexin signaling in maintenance of hearing sensitivity following noise exposures. We will also examine the noise-induced local immune responses of the cochlea by assessing the inflammatory state and numbers of immune cells infiltrating the cochlea following Orexin receptor genetic manipulation and noise exposure.

为该提案进行的研究意义重大，因为它代表了对该角色的首次调查 Orexin信号在耳蜗，因此，将导致一个新的信号通路的新的基础知识 与耳蜗功能有关。我们还将确定对听力健康影响的潜在安全问题 与使用一种已经被相当一部分美国人使用的失眠药物有关。 食欲素是大脑中仅在下丘脑神经元中表达的两种肽的家族。 然而，这两种食欲素受体广泛分布在整个大脑中。有缺陷的食欲素信号 与散发性非家族性发作性睡病有关，发作性睡病最常见的形式，因此大多数 食欲素信号的研究针对睡眠/觉醒行为。使用免疫组织化学，我们表明， 食欲素前激素原（两种成熟食欲素肽）及其受体在耳蜗中表达。我们 证明食欲素A/B前激素原基因缺失小鼠（因此缺乏所有食欲素配体）不恢复 噪声暴露后诱发野生型小鼠典型TTS的ABR阈值。这是一个很好的例子。 重要发现，因为Ox 1 R和Ox 2 R是食欲素受体拮抗剂药物的靶点， Suvorexant（Belsomra®）用于治疗失眠。在美国，大约30%的成年人报告有症状 在2013年CDC民意调查之前的一个月里，4%的人报告了处方睡眠辅助剂的使用。虽然睡眠有助于 是指短暂的持续时间使用，他们经常使用很长一段时间（数月至数年）。这是 尤其是对于老年人和患有许多其他疾病（创伤后应激障碍，焦虑， 等）。一个主要的问题是，使用Orexin靶向失眠药物是否存在潜在风险-这些药物是否 药物会使患者面临听力障碍的风险，特别是如果长期持续服用， 药物清除不完全吗这项工作是进一步的相关性，因为睡眠援助往往是 由老年人使用，他们作为一个群体患有异常的睡眠模式/失眠， 正经历着正常的与年龄相关的听力障碍我们这个项目的目标是：1）验证和扩展 我们通过证明哪种受体（Ox 1 R、Ox 2 R或两者） 导致中度噪声暴露后听力损失;以及2）开始评估 观察到的与食欲素信号丢失相关的功能障碍的潜在机制。我们将使用一个 形态学（IHC下传入突触的免疫染色）、生理学（ABR和 DP）和蛋白质表达（细胞因子阵列）分析，以研究食欲素信号传导在 在噪声暴露后保持听力灵敏度。我们还将研究噪音引起的当地 通过评估炎症状态和浸润的免疫细胞数量来评估耳蜗的免疫应答 Orexin受体基因操作和噪声暴露后的耳蜗。