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

基本信息

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
项目类别：
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

项目摘要

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.

抽象的视网膜神经节细胞（RGC）是眼睛和大脑之间的唯一连接。他们特别容易退化，其损伤和死亡会导致青光眼、糖尿病等疾病的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并不集中于专门拯救 RGC，但减轻疾病进展的明显驱动因素。例如，当前青光眼治疗的重点是降低升高的眼压 (IOP)，但对大多数患者无效的患者。此外，许多青光眼患者也有 RGC 变性，但 IOP 并未升高。因此，新在退行性疾病中保护 RGC 的治疗是一个重要的未满足的临床需求。虽然 RGC 细胞死亡会导致视力丧失，即使在严重的退行性疾病中，RGC 死亡也是不完全的受影响的患者和稳健的动物模型。了解一些 RGC 本身如何持续退化条件可以为新治疗策略的制定提供信息。为了确定本地应对策略，我们将直接观察单个 RGC 在变性之前和过程中的细胞特征，重点关注细胞稳态。我们已经建立了基因编码的纵向体内 2 光子成像 RGC 中的生物传感器可在单一 RGC 分辨率下重复直接观察能量和 Ca2+ 稳态在很长一段时间内。这种方法允许通常需要任一端的测量点样本采集、从多个视网膜汇集 RGC，或两者兼而有之；模糊人口的限制异质性和个体细胞动力学。我们将表征能量和 Ca2+ 的基线异质性稳态以及轴突损伤后的动态，并将这些测量值与 RGC 直接相关生存或死亡。体内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研究。我们的初步数据表明，小鼠在视神经挤压中原生存活的 RGC 具有能量和 Ca2+ 稳态的显着特征，可以在诱导变性之前将其与整个 RGC 群体区分开来。这些结果强烈地表明稳态设定点会影响严重退化模型中的 RGC 生存结果。更远，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 RGC 使用基因过度表达或抑制干预来模拟弹性 RGC 的特性。这样做我们可以验证我们的观察结果是相关的还是因果关系。因此，我们提案的目标是：彻底定义存活良好的 RGC 的稳态指纹；确定轴切术是如何诱导的退化会影响存活良好的 RGC 与存活不良的 RGC 的稳态；并翻译这个信息投入到保护 RGC 的干预措施中，否则 RGC 就会退化。综合我们的实验将确定并验证保护 RGC 的新方法。