Identifying and leveraging strategies of inherently resilient retinal neurons to treat degeneration

识别和利用固有弹性视网膜神经元的策略来治疗退化

• 批准号: 10446816
• 负责人: Philip Raymond Williams
• 金额: $ 39.01万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10446816
• 关键词: Affect; Animal Model; Axon; Axotomy; Biological Assay; Biosensor; Blindness; Brain; Caliber; Cell Death; Cell Energetics; Cell Survival; Cells; Cessation of life; Clinical; Coping Skills; Data; Degenerative Disorder; Development; Diabetic Neuropathies; Diabetic Retinopathy; Disease; Disease Progression; Endoplasmic Reticulum; Eye; Fingerprint; Foundations; Gene Expression; Genes; Glaucoma; Goals; Heterogeneity; Homeostasis; Human; Image; Individual; Intervention; Maintenance; Measurement; Measures; Metabolic; Metabolism; Mitochondria; Modeling; Mus; Nature; Nerve Crush; Nerve Degeneration; Neurons; Optic Nerve; Optic Nerve Glioma; Optic Nerve Injuries; Optic Neuritis; Outcome; Pathway interactions; Patients; Pharmacology; Phenotype; Physiologic Intraocular Pressure; Population; Population Heterogeneity; Production; Property; Proteins; Regulation; Repression; Research; Resolution; Rest; Retina; Retinal Ganglion Cells; Role; Source; Testing; Therapeutic Agents; Time; Translating; Trauma; Vision; age related neurodegeneration; axon injury; cell type; experimental study; human disease; human model; imaging approach; improved; in vivo; in vivo imaging; knock-down; legally blind; neuron loss; novel; novel strategies; novel therapeutics; optic nerve disorder; overexpression; preservation; prevent; resilience; response; retinal ganglion cell degeneration; retinal neuron; sample collection; sight restoration; survival outcome; trait; treatment strategy; two-photon

ABSTRACT Retinal ganglion cells (RGCs) are the sole connection between the eye and the brain. They are particularly susceptible to degeneration, and their damage and death leads to vision loss in conditions like glaucoma, diabetic retinopathy, optic nerve glioma, and optic neuritis. Most treatments for these diseases are not focused on specifically rescuing RGCs, but on relieving apparent drivers of disease progression. For example, current glaucoma treatments focus on reducing elevated intraocular pressure (IOP), but are not effective in the majority of patients. Further, many glaucoma patients also have RGC degeneration without IOP elevations. Thus, new treatments to preserve RGCs in degenerative diseases represent an important unmet clinical need. Although RGC cell death leads to vision loss, RGC death in degenerative conditions is incomplete even in severely affected patients and robust animal models. Understanding how some RGCs natively persist in degenerative conditions can inform the development of new treatment strategies. To identify native coping strategies, we will directly observe cellular traits of individual RGCs prior to and during the course of degeneration, focusing on cellular homeostasis. We have established longitudinal, in vivo, 2-photon imaging of genetically encoded biosensors in RGCs to directly observe energetic and Ca2+ homeostasis at single RGC resolution repeatedly over a protracted period of time. This approach allows for measurements that would normally require either end point sample collection, pooling of RGCs from multiple retinae, or both; limitations that obscure population heterogeneity and individual cell dynamics. We will characterize baseline heterogeneity of energetic and Ca2+ homeostasis, along with dynamics following axon injury and directly relate these measurements with RGC survival or death. Mechanisms of homeostasis are highly relevant to a range of degenerative diseases but have yet to be thoroughly investigated in models of RGC degeneration. Our preliminary data indicate that mouse RGCs that natively survive optic nerve crush have salient features of energetic and Ca2+ homeostasis that can be distinguished from the RGC population as a whole prior to induction of degeneration. These results strongly suggest that homeostatic set-points influence RGC survival outcomes in a severe degeneration model. Further, we will conduct experiments to preserve RGCs in optic nerve crush models by manipulating these pathways to mimic the properties of resilient RGCs using both gene overexpression or repression interventions. Doing so we can validate which of our observations are correlative or causative. The goals of our proposal are thus to: more thoroughly define the homeostatic fingerprint of well surviving RGCs; determine how axotomy induced degeneration impinges on homeostasis of well-surviving versus poorly-surviving RGCs; and translate this information into interventions that preserve RGCs that would otherwise degenerate. Taken together our experiments will identify and validate new approaches towards protection of RGCs.

摘要 视网膜神经节细胞(RGC)是眼睛和大脑之间唯一的连接。他们特别是 容易退化，在青光眼、糖尿病等情况下，它们的损伤和死亡会导致视力丧失 视网膜病变、视神经胶质瘤和视神经炎。这些疾病的大多数治疗方法都没有集中在 特别是拯救RGC，但缓解疾病进展的明显驱动因素。例如，Current 青光眼治疗侧重于降低升高的眼压，但在大多数情况下并不有效 病人的数量。此外，许多青光眼患者也有RGC变性，但眼压没有升高。因此，新的 在退行性疾病中保存RGC的治疗代表着一个重要的未得到满足的临床需求。虽然 RGC细胞死亡导致视力丧失，退行性条件下的RGC死亡即使在严重的情况下也是不完全的 受影响的患者和健壮的动物模型。了解一些视网膜节细胞如何天生坚持退行性变 病情可以为新的治疗策略的发展提供信息。为了确定本地应对策略，我们将 直接观察单个视网膜节细胞在退变前和退变过程中的细胞特性，重点是 细胞动态平衡。我们已经建立了基因编码的纵向、活体、双光子成像 RGC细胞中的生物传感器可直接观察能量和钙离子在单一RGC分辨率下的稳态 在很长一段时间内。这种方法允许测量通常需要两端的任何一端 点样本采集，从多个视网膜汇集RGC，或两者兼而有之；模糊人群的限制 异质性和个体细胞动力学。我们将表征高能和钙离子的基线非均质性 轴突损伤后的动态平衡和动态平衡，这些测量与RGC直接相关 生死存亡。动态平衡机制与一系列退行性疾病高度相关，但 尚未在RGC变性模型中进行彻底的研究。我们的初步数据显示，老鼠 在视神经挤压中存活下来的视网膜神经节细胞具有能量和钙离子稳态的显著特征，可以 在被诱导退化之前，从整个RGC群体中区分出来。这些结果有力地证明了 提示在严重退变模型中，内环境平衡设定点影响RGC的生存结果。此外， 我们将进行实验，通过操纵这些通路来保存视神经挤压模型中的视网膜节细胞 使用基因过度表达或抑制干预来模仿有弹性的视网膜节细胞的特性。这样做，我们 可以验证我们的观察结果中哪些是相关的或有因果关系的。因此，我们建议的目标是：更多 彻底确定存活良好的视网膜节细胞的动态平衡指纹；确定轴突切断术如何诱导 退化影响存活良好和存活不良的视网膜节细胞的内稳态； 将信息转化为干预措施，以保存原本会退化的区域GC。把我们的 实验将确定和验证保护RGC的新方法。