Ghrelin Modulation of CaV 2.2 Channels After Spinal Cord Injury

脊髓损伤后 Ghrelin 对 CaV 2.2 通道的调节

基本信息

批准号：
10750130
负责人：
Hannah J Goudsward
金额：
$ 3.45万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-01 至 2026-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10750130
关键词：
Acute Address Afferent Neurons Animal Model Appetite Stimulants Attenuated Binding Biological Models Calcium Calcium Channel Cells Chemicals Chest Cholecystokinin Chronic Clinical Closure by clamp Coupled Couples Cutaneous Diabetes Mellitus Disease Electrophysiology (science)Fiber Functional disorder Future G-Protein-Coupled Receptors Gastrointestinal Hormones Gastroparesis Genetic Transcription Goals Health Heterotrimeric GTP-Binding Proteins Hormones Imaging Techniques Immunohistochemistry Impairment In Vitro Individual Injury Knowledge Ligands Mechanics Mediating Modeling Molecular Motor Motor output Nerve Neurons Nodose Ganglion Obesity Outcome Pathway interactions Peptides Peripheral Polymerase Chain Reaction Presynaptic Terminals Quality of life Rattus Receptor Activation Reflex action Reporting Reverse Transcription Role Scientist Sensory Signal Pathway Signal Transduction Spinal cord injury Spinal cord injury patients Stimulus Stomach Structure Synapses Techniques Testing Training Vagus nerve structure Work afferent nerve cell motility comorbidity experimental study gastrointestinal ghrelin growth hormone secretagogue receptor improved in vivo innovation insight mimetics motility disorder neuronal cell body neuronal excitability neurotransmitter release patch clamp pre-clinical receptor response social therapeutic target transmission process voltage

项目摘要

Project Summary Gastrointestinal (GI) dysfunction after spinal cord injury (SCI) is a highly prevalent, but significantly understudied comorbidity that negatively impacts quality of life for individuals with SCI. Increasing evidence suggests impaired vagal activity is a primary cause of upper GI dysfunction after injury. Under normal conditions, gastric reflexes are coordinated by the vagus nerve. The vagus nerve contains both afferent fibers that convey sensory information to central structures and efferent fibers that carry motor output needed for gastric contractions. Previous work in our lab has demonstrated that following injury, vagal afferents are significantly less responsive to chemical stimuli, including the gut peptide ghrelin. Ghrelin is an orexigenic hormone that normally serves to decrease vagal afferent activity and increase gastric motility by binding to the growth hormone secretagogue receptor (GHSR1a), a G protein-coupled receptor, expressed along the vagal afferents. The cellular mechanisms underlying ghrelin’s ability to modulate vagal afferent activity in both healthy and disease states have yet to be fully elucidated. This proposal will utilize an animal model of SCI combined with molecular and imaging techniques, in vitro patch-clamp electrophysiology, and in vivo nerve recordings to identify mechanisms underlying the loss of vagal sensitivity post-SCI. The proposed experiments will investigate the central hypothesis that GHSR1a-mediated inhibition of calcium currents is dysregulated in gastric-projecting nodose ganglia neurons after SCI. Based upon our preliminary observations, we will test the hypothesis with two specific aims. Aim 1 will determine the precise mechanism underlying GHSR1a modulation of voltage-gated Ca2+ channels (CaV2.2 or N-type) in gastric-projecting vagal afferent neurons of naïve rats using whole-cell patch- clamp electrophysiology. Aim 2 will utilize immunohistochemistry, single-cell quantitative reverse transcription polymerase chain reaction (qRT-PCR), electrophysiological techniques, and in vivo nerve recordings to identify whether the GHSR1a-mediated effects of ghrelin on N-type Ca2+ channel currents and gastric vagal afferent excitability are dysregulated following SCI. This proposal will provide critical information regarding how changes to GPCR-mediated inhibition of CaV channels impairs gastric vagal afferent activity following injury. In addition, the proposed work will benefit future studies investigating the use of ghrelin mimetics to treat gastric dysmotility associated with a broad range of conditions including SCI, diabetes mellitus, and obesity.

项目摘要脊髓损伤（SCI）后胃肠道（GI）功能障碍是高度普遍的，但显着研究的合并症会对SCI患者产生负面影响。越来越多的证据暗示迷走神经活动受损是受伤后胃肠道功能障碍的主要原因。在正常情况下条件，胃反射由迷走神经协调。迷走神经包含两个传入的纤维将感官信息传达给中央结构和有效的纤维，这些纤维带有胃输出所需的电动机输出收缩。我们实验室的先前工作表明，在受伤后，迷走神经的传入非常明显对化学刺激的反应较小，包括肠道剥离的生长素素。 ghrelin是一种甲龙通常用来减少迷走神经的传入活动，并通过与生长马酮结合来增加胃运动 G蛋白偶联受体（GHSR1A）沿迷走神经传入表示。细胞生长素释放能力在健康和疾病状态下调节迷走神经活动的能力的机制尚未完全阐明。该建议将利用SCI的动物模型与分子和成像技术，体外斑块钳电生理学和体内神经记录以识别机制 SCI后迷走神经敏感性的丧失的根本。提出的实验将研究中央假设GHSR1A介导的钙电流抑制作用在胃突出淋巴结中失调科学后神经元神经元。根据我们的初步观察，我们将用两个特定目标。 AIM 1将确定电压门控CA2+的GHSR1A调制的确切机制使用全细胞斑块 - 夹具电生理学。 AIM 2将利用免疫组织化学，单细胞定量逆转录聚合酶链反应（QRT-PCR），电生理技术和体内神经记录以鉴定 GHSR1A介导的生长素蛋白对N型Ca2+通道电流和胃迷走神经传入的作用是否存在 SCI后，兴奋性失调。该建议将提供有关如何改变的关键信息为了GPCR介导的CAV通道的抑制作用会损害受伤后胃迷走神经活动。此外，拟议的工作将使未来研究的研究有益于使用生长素蛋白模拟物治疗胃不良症的研究与包括SCI，糖尿病和肥胖症在内的广泛疾病有关。