Role of ryanodine receptor dysfunction after spinal cord injury

兰尼碱受体功能障碍在脊髓损伤后的作用

• 批准号: 10515284
• 负责人: Helen M Bramlett
• 金额: --
• 依托单位: JAMES J PETERS VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10515284
• 关键词: Affect; Aging; American; Animal Model; Area; Atrophic; Behavioral; Binding; Calcium; Collaborations; Contusions; Coupling; Data; Deterioration; Disseminated Malignant Neoplasm; Dissociation; Drug usage; Fatigue; Fiber; Force of Gravity; Functional disorder; Gait; Hand; Hindlimb; Impairment; Individual; Injury; Intervention; Knock-out; Knowledge; Lead; Lesion; Link; Locomotion; Longevity; Modeling; Motor; Motor Neurons; Mus; Muscle; Muscle Contraction; Muscle Weakness; Muscle function; NADH oxidase; Outcome; Oxides; Paralysed; Pharmaceutical Preparations; Pharmacologic Substance; Pharmacology; Physiological; Production; Quality of Care; Quality of life; Reactive Oxygen Species; Recovery of Function; Rehabilitation therapy; Research Personnel; Resistance; Role; Ryanodine Receptor Calcium Release Channel; Ryanodine Receptors; Sarcoplasmic Reticulum; Skeletal Muscle; Source; Spinal Cord; Spinal Cord Contusions; Spinal Cord transection injury; Spinal cord injury; Testing; Thoracic spinal cord structure; Time; United States Department of Veterans Affairs; Ursidae Family; Veterans; Weight; Work; arm; conditional knockout; disability; effective therapy; experience; experimental study; gait examination; improved; improved functioning; inhibitor; muscle strength; neuromuscular function; novel; oxidation; prevent; response; small molecule; treatment effect

Muscles paralyzed by spinal cord injury (SCI) atrophy extensively, are weaker, fatigue more quickly and generate lower specific tension (force produced per unit of cross-sectional area), such that they generate less force in response to maximal motor neuron activation. For individuals with motor-incomplete lesions, interventions that improve specific force and/or fatigue resistance would be obvious opportunities to improve function. A newly recognized cause of impaired specific force production is oxidation/nitrosylation of ryanodine receptors (RyR) which results in dissociation of calstabin and spontaneous opening of RyR thereby impairing RyR gating; the ultimate physiological effect of RyR dysfunction is diminished force of muscle contraction and lower muscle endurance. Small molecules such as S107 bind oxidized/nitrosylated RyR and improve specific force by as much as 50%. Our preliminary data demonstrates extensive oxidation/nitrosylation of RyR in muscle after SCI thus implicating RyR dysfunction in reduced specific force production and endurance of paralyzed muscle after SCI. These changes in RyR are associated with increased expression of NADH oxidase 4 (Nox4) which is a potent source of reactive oxygen species (ROS) that has been linked to RyR. A direct link between Nox4 and oxidation/nitrosylation of RyR is supported by findings that binding of Nox4 to RyR is also increased in muscle after SCI. The overarching objectives of this application are to test the possibility that administration of S107 or a Nox4 inhibitor after SCI will improve skeletal muscle specific tension and endurance, and hence function, and to investigate the role of Nox4 in oxidation/nitrosylation of RyR in skeletal muscle after SCI. Aim 1. To determine the role of elevated Nox4 expression in the oxidation/nitrosylation of RyR in muscle after spinal cord transection. Hypothesis: oxidation/nitrosylation of RyR after SCI results from increased expression and activity of Nox4. Approach. Aim 1A. We will compare SCI and sham-operated groups over time after a spinal cord transection at various times between 1 and 56 days after SCI. We will examine the temporal relationships between oxidation/nitrosylation of RyR and dissociation of calstabin from RyR with changes in Nox4 expression. Aim 1B: Effects of a conditional knockout of Nox4 in skeletal muscle on muscle strength, specific force, fatigue, RyR oxidation after SCI will be determined. Aim 1C: We will compare muscle force production, specific force, fatigue, RyR oxidation/nitrosylation and binding of RyR to calstabin between spinal cord transected mice treated with a Nox4 inhibitor or vehicle. Aim 2) To test the effects of S107 on muscle force production and RyR-calstabin binding interactions after spinal cord transection. Hypothesis: administration of S107 will improve muscle specific force and endurance and increase calstabin binding to RyR but will not alter RyR oxidation/nitrosylation. Approach: We will compare muscle specific force, endurance, binding of calstabin to RyR, and RyR oxidation/nitrosylation between SCI groups administered S107 or vehicle. Aim 3. To A) determine whether S107 or a Nox4 inhibitor improves functional recovery after a contusion SCI. Hypothesis: S107 or a Nox4 inhibitor improves functional recovery in a graded contusion model of mid-thoracic SCI in mice. Approach: Following a mild, moderate or severe contusion spinal cord injury, mice will be treated with the most effective drug (either S107 or GKT137831) from Aims 1 and 2 or vehicle. Effects of the treatment on locomotor function and gait will be determined. Expected Outcomes and Benefits to Veterans. Knowledge gained from such studies may result in new pharmacologic or rehabilitation treatments to improve function after SCI.

因脊髓损伤(SCI)广泛萎缩而瘫痪的肌肉更虚弱，疲劳更快和 产生较低的比张力(单位横截面面积产生的力)，以便它们产生 对运动神经元的最大激活反应较小的力。对于运动不完全性损伤的患者， 提高比力和/或抗疲劳能力的干预措施显然是提高的机会。 功能。一个新发现的比力产生受损的原因是氧化/亚硝化 Ryanodine受体(RyR)导致钙调蛋白解离和RyR自发开放 从而损害RyR门控；RyR功能障碍的最终生理效应是减弱 肌肉收缩，肌肉耐力下降。小分子如S107结合氧化/亚硝化 RyR，并提高比力高达50%。我们的初步数据显示 脊髓损伤后肌肉中RyR的氧化/亚硝化，从而导致比力降低的RyR功能障碍 脊髓损伤后瘫痪肌肉的产生和耐力。RyR中的这些变化与 NADH氧化酶4(NOX4)的表达增加，这是一个有效的活性氧来源 (ROS)已链接到RyR。NOX4和RyR的氧化/亚硝化之间的直接联系是 研究发现，脊髓损伤后肌肉中NOX4与RyR的结合也增加了。最重要的是 本应用的目的是测试S107或NOX4抑制剂在 脊髓损伤将改善骨骼肌比张力和耐力，从而改善功能，并研究 NOX4在脊髓损伤后骨骼肌氧化/亚硝化RyR中的作用 目的1.确定NOX4表达升高在RyR氧化/亚硝化过程中的作用。 脊髓横断后的肌肉。假设：脊髓损伤后RyR的氧化/亚硝化是由 NOX4的表达和活性增加。接近。目标1 A。我们将比较脊髓损伤和假手术 脊髓横断后不同时间组脊髓损伤后1~56天。我们会 研究RyR的氧化/亚硝化和钙解离之间的时间关系 来自RyR的NOX4表达的变化。目的1B：骨骼中条件基因敲除NOX4的作用 肌肉对脊髓损伤后的肌肉力量、比力、疲劳、RyR氧化作用进行测定。目标1C：我们 将比较肌肉力量产生、比力、疲劳、RyR氧化/亚硝化和RyR结合 用NOX4抑制剂或赋形剂治疗脊髓横断小鼠之间的钙化蛋白。 目的2)检测S107对肌力产生和RyR-calstain结合的影响 脊髓横断后的相互作用。假设：服用S107可以改善肌肉 比力量和耐力，增加钙调蛋白与RyR的结合，但不会改变RyR 氧化/亚硝化。方法：我们将比较肌肉比力、耐力、钙结合蛋白与 S107组和赋形剂组脊髓损伤后RyR、RyR氧化/亚硝化反应。 目的3)确定S107或NOX4抑制剂是否能改善术后功能恢复 脊髓挫伤。假设：S107或NOX4抑制剂可改善分级挫伤的功能恢复 小鼠胸中段脊髓损伤模型的建立。治疗方法：轻、中、重度脊髓挫伤 小鼠将接受AIMS 1和AIMS 2中最有效的药物(S107或GKT137831)或 车辆。治疗对运动功能和步态的影响将被确定。 退伍军人的预期结果和福利。从这种研究中获得的知识可能会导致 新的药物或康复治疗以改善脊髓损伤后的功能。

项目成果

Muscle-restricted Nox4 knockout partially corrects muscle contractility following spinal cord injury in mice.

肌肉限制性 Nox4 敲除可部分纠正小鼠脊髓损伤后的肌肉收缩力。

• DOI: 10.1101/2023.08.04.551985
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Toro,CarlosA;DeGasperi,Rita;Aslan,Abdurrahman;Johnson,Nicholas;Siddiq,MustafaM;Chow,Christine;Zhao,Wei;Harlow,Lauren;Graham,Zachary;Liu,Xin-Hua;Sadoshima,Junichi;Iyengar,Ravi;Cardozo,ChristopherP
• 通讯作者: Cardozo,ChristopherP