An interneuronal signaling network governs the fate of retinal ganglion cells after optic nerve injury

神经元间信号网络控制视神经损伤后视网膜神经节细胞的命运

• 批准号: 10379365
• 负责人: PAUL ALLEN ROSENBERG
• 金额: $ 50.16万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10379365
• 关键词: Acute; Amacrine Cells; Axon; Back; Brain; Cell Death; Cell Survival; Cell physiology; Cells; Data; Event; Exocytosis; Eye; Failure; Female; Gene Deletion; Generations; Genetic; Glaucoma; Glutamate Transporter; Glutamates; Goals; Guidelines; Human; Immunohistochemistry; Injury; Inner Plexiform Layer; Interneurons; Knowledge; Link; MAP Kinase Modules; Mediating; Metallothionein; Microspheres; Mitogen-Activated Protein Kinases; Modeling; Molecular; Muller' s cell; Mus; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; NR1 NMDA receptor; Natural regeneration; Nature; Nerve Crush; Nerve Degeneration; Neurons; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Optic Disk; Optic Nerve; Optic Nerve Injuries; Pathway interactions; Pear; Pharmacology; Phospho-Specific Antibodies; Phosphorylation; Physiology; Plasma; Play; Population; Potassium Channel; Presynaptic Terminals; Process; Production; Publishing; Receptor Activation; Receptor Inhibition; Recovery; Regenerative capacity; Reporting; Research; Retina; Retinal Ganglion Cells; Role; Sex Differences; Signal Pathway; Signal Transduction; Site; Source; Synapses; System; Testing; Traumatic Nerve Injury; Traumatic injury; United States National Institutes of Health; Up-Regulation; Visual; Work; Zinc; axon injury; axon regeneration; base; cell type; central nervous system injury; chelation; experimental study; extracellular; ganglion cell; genetic approach; improved; indium arsenide; inhibitor; injured; insight; ischemic injury; male; mouse model; nerve damage; nerve injury; neuron loss; novel; operation; optic nerve regeneration; p38 Mitogen Activated Protein Kinase; presynaptic; protein activation; regenerative; retinal damage; therapy development; trafficking; voltage

Project Summary The retina and optic nerve have been widely studied for insights into factors that suppress or promote cell survival and axon regeneration after CNS injury. Following injury to the optic nerve, retinal ganglion cells (RGCs), the pro- jection neurons of the eye, cannot regenerate their axons and begin to die after a few days. Despite the development of treatments that improve RGC survival and/or axon regeneration, levels of visual recovery achieved to date remain modest, underscoring the need to better understand the mechanisms that produce cell death and regenerative failure. We recently reported (Li et al., PNAS, 2017, ref. 1) that optic nerve injury leads to a rapid elevation of mobile/free zinc (Zn2+) in synaptic terminals of amacrine cells, followed by exocytosis and Zn2+ accumulation within RGCs; and that Zn2+ chelation leads to long-term survival of many RGCs and considerable axon regeneration. Our preliminary data indicate that the mechanisms underlying Zn2+ elevation involve a previously unknown, multi-cellular network that utilizes non-classical signaling mechanisms and that ultimately determines the fate of RGCs. This network ap- pears to involve phosphorylation of a K+ channel in RGCs by a signal conveyed up the injured axons; retrograde sig- naling between injured RGCs and interneurons (or Muller glia) via elevation of extracellular K+, causing reversal of the glutamate transporter GLT-1 and glutamate efflux; this in turn activates NMDA receptors, leading to Ca2+ entry, activation of neuronal nitric oxide (NO) synthase-1 (NOS1), and NO-mediated liberation of Zn2+ from metal- lothionein(s). This sequence is based on preliminary results using pharmacological inhibitors and immunohistochem- istry, but precise knowledge of the specific cell types and signals involved remains to be established. Based on the observation that NOS1- mediated NO generation lies directly upstream of Zn2+ liberation, Aims 1 and 2 will work back from this point to identify the cellular populations and signals that link optic nerve damage to RGC death. Aim 1 will test the hypothesis that glutamate efflux from bipolar or Mueller cells (via reversal of the glutamate transporter GLT-1) and activation of NMDA receptors on NOS1-positive amacrine cells lie directly upstream of NO generation. Aim 2 will test the hypothesis that the further upstream steps involve activation of a MAP kinase cascade and/or Ca2+ signaling in injured RGCs, leading to phosphorylation and activation of potassium channels (and possibly other channels) in RGCs, causing an elevation of extracellular K+ that leads to a reversal of the normal operation of glu- tamate transporters in bipolar or Mueller cells. Aim 3 will test the hypothesis that this pathway contributes to RGC death in a mouse model of glaucoma. In keeping with NIH guidelines, the proposed studies will use both male and female mice in a key experiment to determine whether sex differences exist in the signaling pathway we have un- covered that might provide further insights into the mechanisms underlying cell death and regenerative failure. These studies will define a novel multi-cellular signaling network in the retina that regulates the viability and regenerative capacity of RGCs after optic nerve injury and perhaps in glaucoma.

项目摘要 人们对视网膜和视神经进行了广泛的研究，以了解抑制或促进细胞存活的因素 和CNS损伤后轴突再生。在视神经损伤后，视网膜神经节细胞（RGC）， 眼睛的投射神经元不能再生它们的轴突，并且开始在几天后死亡。尽管开发 在改善RGC存活和/或轴突再生的治疗中，迄今为止达到的视觉恢复水平仍然是 适度，强调需要更好地了解产生细胞死亡和再生失败的机制。 我们最近报道（Li et al.，PNAS，2017年，参考文献1）视神经损伤导致移动的/自由的快速升高 锌（Zn 2+）在无长突细胞的突触末梢中，随后是胞吐作用和RGCs内的Zn 2+积累;以及 Zn 2+螯合导致许多RGC的长期存活和相当大的轴突再生。我们的初步 数据表明，Zn 2+升高的机制涉及一个以前未知的多细胞网络， 其利用非经典信号传导机制并最终决定RGC的命运。网络AP- 梨涉及通过受损轴突传递的信号磷酸化RGCs中的K+通道;逆行信号， 通过升高细胞外K+，在受损的RGCs和中间神经元（或Muller胶质细胞）之间发生naling，导致 谷氨酸转运蛋白GLT-1和谷氨酸外流;这反过来激活NMDA受体，导致Ca 2+进入， 激活神经元型一氧化氮合酶-1（NOS 1），以及NO介导的Zn 2+从金属- 碘硫蛋白该序列是基于使用药理学抑制剂和生物化学的初步结果， 虽然如此，但有关特定细胞类型和信号的精确知识仍有待建立。基于 观察到NOS 1介导的NO产生直接位于Zn 2+释放的上游，目标1和2将起作用 从这一点回来，以确定视神经损伤与RGC死亡之间的细胞群和信号。目的 1将检验谷氨酸从双极或Mueller细胞流出（通过谷氨酸转运蛋白的逆转）的假设， GLT-1）和NOS 1阳性无长突细胞上NMDA受体的激活直接位于NO产生的上游。 目的2将检验进一步的上游步骤涉及MAP激酶级联的激活和/或 受损RGC中的Ca 2+信号传导，导致钾通道的磷酸化和激活（以及可能的其他 通道），引起细胞外K+的升高，导致glu- 双极或Mueller细胞中的tamate转运蛋白。目标3将检验这一通路对RGC有贡献的假设 青光眼小鼠模型中的死亡。为了与NIH的指导方针保持一致，拟议的研究将使用男性和 在一个关键的实验中，雌性小鼠，以确定性别差异是否存在于信号通路中，我们没有， 覆盖，可能提供进一步的见解，细胞死亡和再生失败的机制。这些 研究将确定一种新的多细胞信号网络在视网膜调节的活力和再生， 视神经损伤后RGCs的能力，可能在青光眼。

项目成果

Neuronal Loss of the Glutamate Transporter GLT-1 Promotes Excitotoxic Injury in the Hippocampus.

• DOI: 10.3389/fncel.2021.788262
• 发表时间: 2021
• 期刊: Frontiers in cellular neuroscience
• 影响因子: 5.3
• 作者: Rimmele TS;Li S;Andersen JV;Westi EW;Rotenberg A;Wang J;Aldana BI;Selkoe DJ;Aoki CJ;Dulla CG;Rosenberg PA
• 通讯作者: Rosenberg PA