Regulation of Calcium Signaling in Retinal Ganglion Cells after Nerve Injury

神经损伤后视网膜神经节细胞钙信号传导的调节

• 批准号: 8278451
• 负责人: NICHOLAS C. BRECHA
• 金额: --
• 依托单位: VA GREATER LOS ANGELES HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8278451
• 关键词: Affect; Animal Model; Apoptosis; Axon; Axotomy; Blast Injuries; Blindness; Blunt Trauma; Calcium Signaling; Cell Death; Cell Survival; Cells; Characteristics; Clinical; Complex; Craniocerebral Trauma; Development; Disease; Electrophysiology (science); Eye; Eye Injuries; Eye diseases; Face; Free Radicals; Frequencies; Functional disorder; General Population; Genes; Glaucoma; Gliosis; Goals; Head; Health; Healthcare; Hour; Image; Immune; Immunohistochemistry; Injury; Investigation; Knowledge; Lead; Ligation; Mediating; Membrane; Modeling; Mus; Nerve; Nerve Crush; Neurotransmitters; Optic Nerve; Optic Nerve Injuries; Optic Nerve Transections; Optics; Physiological; Program Reviews; Property; Proteins; Recovery; Regulation; Reporting; Retina; Retinal; Retinal Ganglion Cells; Role; Signal Transduction; Small Interfering RNA; Staging; Stroke; Structure; Swelling; Testing; Trauma; Traumatic Brain Injury; Up-Regulation; Vascular Diseases; Veterans; Vision; Visual; Visual impairment; Western Blotting; cell injury; channel blockers; chronic pain; effective therapy; ganglion cell; injured; nerve injury; novel; novel strategies; novel therapeutic intervention; optic nerve disorder; patch clamp; prevent; public health relevance; research study; response; sciatic nerve; tool; treatment strategy; vector; voltage

DESCRIPTION (provided by applicant): Ocular and traumatic brain injuries (TBI) from blunt trauma or blast injury to the head occur with high frequency on the battlefield, and they are often accompanied by multiple visual dysfunctions, acuity loss and blindness in one or both eyes. Optic neuropathies are characterized by primary injury to the optic nerve, and loss of ganglion cells and their axons. Ganglion cell death is mediated in part by excessive intracellular Ca2+ ([Ca2+]i) loads following injury. Consistent with this finding is the enhancement of retinal ganglion cell survival after optic nerve crush with the administration of Ca2+ channel antagonists, which inhibit both L- and T-type Ca2+ currents, and reduce secondary ganglion cell death. The rationale underlying the proposed studies is that reduction of ganglion cell intracellular Ca2+ levels by regulation of Ca2+ channel activity may be an important component of protective strategies for the treatment of retinal injury. Suppression of excessively elevated [Ca2+]i in ganglion cells would provide a temporal window for ganglion cell survival and axonal recovery following injury. Proposed studies will test the hypothesis that suppression of elevated [Ca2+]i following nerve injury enhances ganglion cell survival. Specific aim 1 will define the signaling role of L- and T-type Ca2+ channels, and their accessory proteins (23 and 124) in mouse retinal ganglion cells. Experiments will determine a) the expression of L- and T-type Ca2+ channels and their accessory proteins by ganglion cells, and b) characterize the physiological and biophysical properties of L- and T-type Ca2+ currents of ganglion cells. Specific aim 2 will test the hypothesis that ganglion cell Ca2+ signaling is dysregulated immediately following and several days after optic nerve crush or transection. Investigations will determine if there are short (12 and 24 hours)- and long (10 and 20 days)-term alterations of a) the expression of L- and T-type, and 23 and 124 Ca2+ channel subunits by ganglion cells, and b) membrane mechanisms that mediate Ca2+ currents and signaling in ganglion cells following optic nerve injury. Specific aim 3 will test the hypothesis that Ca2+ channel antagonists and small interfering RNA (siRNA) antisense Ca2+ channel subunit vectors regulate Ca2+ signaling, and enhance ganglion cell survival after optic nerve injury. Investigations will determine if a) the L- and T-type Ca2+ channel antagonist, lomerizine, and b) antisense T-type (CaV3.1 and CaV3.2), and 23 and 124 Ca2+ channel subunit siRNA vectors, modulate Ca2+ signaling and enhance ganglion cell survival following optic nerve injury. Proposed studies will elucidate Ca2+ signaling in normal and injured ganglion cells, and develop novel approaches for controlling elevated intracellular Ca2+ following nerve injury, which will enhance ganglion cell survival, a key step in saving vision. These studies are consistent with the health-related goals of the Veterans Adminstration to develop highly effective and novel treatments for eye injury and disease. PUBLIC HEALTH RELEVANCE: Project Narrative Traumatic brain injury (TBI) is a common casualty in the battlefield. Ocular trauma frequently occurs with TBI, which results in visual impairments, including acuity loss and blindness often due to optic nerve and retina injury. This Merit Review application will test the hypothesis that suppression of elevated intracellular Ca2+ induced by nerve injury enhances ganglion cell survival, a key step in saving vision. Planned studies will use animal models of ocular nerve injury and test novel strategies for controlling Ca2+ signaling using Ca2+ channel antagonists and antisense siRNAs for Ca2+ channels to reduce ganglion cell loss, thus setting the stage for developing new therapeutic approaches to ameliorate ocular damage and vision. These investigations are consistent with the health-related goals of the Department of Veteran Affairs to develop highly effective treatments for eye injuries and disease, and to prevent impaired vision and blindness.

描述（由申请人提供）： 从钝性创伤或爆炸损伤到头部的眼部和创伤性脑损伤（TBI）在战场上以高频出现，并且通常伴随着多种视觉功能障碍，一只或两只眼睛中的敏锐性丧失和失明。视神经病的特征是视神经的一级损伤以及神经节细胞及其轴突的丧失。受伤后的细胞内Ca2+（[Ca2+] i）负荷过多，部分是由过度细胞内Ca2+（[Ca2+] I）介导的。与这一发现一致的是视神经挤压后视网膜神经节细胞存活的增强，并抑制了L型和T型Ca2+电流，并减少继发性神经节细胞死亡。提出的研究的基本原理是，通过调节Ca2+通道活性来降低神经节细胞内Ca2+水平可能是治疗视网膜损伤的保护策略的重要组成部分。在神经节细胞中抑制过高的[Ca2+] I的抑制作用将为神经节细胞存活和受伤后轴突恢复提供一个时间窗口。拟议的研究将检验以下假设：神经损伤后抑制[Ca2+] I升高会增强神经节细胞的存活。特定的目标1将定义L-和T型Ca2+通道的信号传导作用，以及其在小鼠视网膜神经节细胞中的辅助蛋白（23和124）。实验将确定a）神经节细胞的L-和T型Ca2+通道及其辅助蛋白的表达，b）表征神经节细胞L-和T型Ca2+电流的生理和生物物理特性。特定的目标2将检验以下假设：神经节细胞Ca2+信号在接下来的几天和横切后几天都失调。调查将确定是否存在短（12和20天）和长（10天和20天） - a）L-和T型的表达，以及通过神经节细胞的23和124 Ca2+通道亚基，b）膜机制，这些机制介导了光静脉损伤后神经节细胞中CA2+电流和信号传导的膜机制。具体目标3将检验以下假设：Ca2+通道拮抗剂和小的干扰RNA（siRNA）反义CA2+通道亚基载体调节Ca2+信号传导，并在视神经损伤后增强神经节细胞存活。研究将确定a）L-和T型Ca2+通道拮抗剂，Lomerizine和b）反义T型（CAV3.1和Cav3.2）以及23和124 Ca2+通道亚基siRNA载体，调节CA2+ CA2+信号传导和增强神经节细胞的生存后，可调节ca2+ sirna siRNA。拟议的研究将阐明正常和受伤的神经节细胞中的Ca2+信号传导，并开发出神经损伤后控制升高细胞内Ca2+的新方法，这将增强神经节细胞的存活，这是节省视力的关键步骤。这些研究与退伍军人守卫的健康相关目标是一致的，以开发针对眼部损伤和疾病的高效和新颖的治疗方法。 公共卫生相关性： 项目叙事创伤性脑损伤（TBI）是战场上常见的伤亡。 TBI经常发生眼部创伤，这会导致视觉障碍，包括敏锐度丧失和失明，通常是由于视神经和视网膜损伤。该优点审查的应用将检验以下假设：神经损伤引起的细胞内Ca2+抑制升高会增强神经节细胞的存活，这是节省视力的关键步骤。计划的研究将使用眼神经损伤的动物模型和测试新策略，以使用Ca2+通道拮抗剂和CA2+通道的反义siRNA来控制Ca2+信号传导，以减少神经节细胞的损失，从而为开发新的治疗方法奠定了阶段，以改善眼部损害和视力。这些调查与退伍军人事务部与健康相关的目标是一致的，以开发针对眼部伤害和疾病的高效治疗，并防止视力和失明受损。