Molecular mechanisms of programmed necrosis in the ischemic retina

缺血性视网膜程序性坏死的分子机制

基本信息

批准号：
10672428
负责人：
Dmitry V Ivanov
金额：
$ 38.38万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10672428
关键词：
Ablation Accidents Affect Animal Model Apoptosis Apoptotic Attention Binding Biochemical Biological CASP8 gene Caspase Cell Death Cell Survival Cell membrane Cells Clinical Complex DNA Damage Data Deubiquitination Event Failure Feedback Functional disorder Genetic Induction of Apoptosis Inflammatory Response Injury Ischemia Literature MAPK8 gene Mediating Mediator Membrane Mitochondria Molecular Molecular Conformation NADPH Oxidase Necrosis Neurons Osmosis Oxidative Stress Pathway interactions Patients Poly(ADP-ribose) Polymerases Polymerase Production Proteins Published Comment Publishing Quality of life Reactive Oxygen Species Reperfusion Injury Reperfusion Therapy Research Respiration Retina Retinal Degeneration Retinal Ganglion Cells Role Signal Transduction Swelling TNF gene Techniques Testing Time Tumor Necrosis Factor Receptor Ubiquitination Vision Visual impairment cell type experimental study functional status multicatalytic endopeptidase complex neurotoxic novel therapeutic intervention oxidative DNA damage prevent response retinal damage retinal ischemia retinal neuron retinal stimulation

项目摘要

PROJECT SUMMARY Retinal ischemia-reperfusion (IR) injury is a common cause of visual impairment worldwide, affecting both patients' quality of life and functional status. Retinal ganglion cell (RGC) survival is critical for vision. However, these retinal neurons are exquisitely sensitive and many of them undergo necrosis and apoptosis after IR. Since RGC apoptosis is executed by programmed mechanisms and can be regulated, significant attention has been given to this type of cell death. At the same time, RGC necrosis did not receive nearly enough consideration, because it was viewed as an accidental and unregulated cellular event. We now know that necrosis, like apoptosis, can be executed by programmed mechanisms. This form of necrotic cell death is called necroptosis. Our published data and literature indicate that RGC necroptosis contributes to IR-induced retinal injury through direct loss of RGCs and induction of associated inflammatory responses. Therefore, since RGC necroptosis is executed by programmed mechanisms and can be regulated, this field of research is of great importance. However, the signaling cascades, which regulate IR-induced RGC necroptosis, still remain unknown. The long-term objective of this project is to identify the signaling cascades that regulate RGC necroptosis after IR. Based on our published data, preliminary studies and published literature, we proposed a molecular mechanism of IR-induced RGC necroptosis. We suggested that IR-induced Tnf signaling in RGCs facilitates formation of a positive-feedback loop for the sustained production of reactive oxygen species (ROS), which promotes poly (ADP-ribose) polymerase 1 (Parp1) over-activation due to significant oxidative DNA damage. Significant Parp1 over-activation in RGCs mediates ATP depletion, leading to subsequent energy failure, which results in cellular dysfunction and eventually in loss of RGC membrane integrity (necrosis). We will employ a wide range of biochemical, molecular and cell biological techniques as well as animal models to verify the proposed molecular mechanism of IR-induced RGC necroptosis in hypothesis-driven mechanistic experiments outlined in the following specific aims: 1) to test the hypothesis that Tnf signaling promotes IR- induced RGC necroptosis; 2) to test the hypothesis that IR-induced RGC necroptosis is promoted by formation of a positive-feedback loop for sustained ROS production in a Tnf signaling-dependent manner; 3) to test the hypothesis that RGC necroptosis is a result of ATP depletion caused by Parp1 over-activation after IR. Thus, since treatment for IR is limited in part because of a lack of understanding of the molecular events leading to RGC death, a greater understanding of RGC necroptosis after IR will lead to new therapeutic strategies for this important and difficult to treat condition.

项目概要视网膜缺血再灌注（IR）损伤是全世界视力障碍的常见原因，影响患者的生活质量和功能状态。视网膜神经节细胞 (RGC) 的存活对于视力至关重要。然而，这些视网膜神经元非常敏感，其中许多神经元在红外线照射后会发生坏死和凋亡。由于RGC细胞凋亡是通过程序化机制执行并且可以调节，因此引起了人们的广泛关注已被给予这种类型的细胞死亡。与此同时，RGC坏死没有得到足够的考虑，因为它被视为意外且不受监管的细胞事件。我们现在知道坏死与细胞凋亡一样，可以通过程序机制执行。这种形式的坏死性细胞死亡是称为坏死性凋亡。我们发表的数据和文献表明，RGC 坏死性凋亡有助于 IR 诱导的 RGC 的直接损失和相关炎症反应的诱导导致视网膜损伤。因此，自从 RGC 坏死性凋亡是通过程序化机制执行的并且可以调节，该研究领域是非常重要。然而，调节 IR 诱导的 RGC 坏死性凋亡的信号级联反应仍然存在未知。该项目的长期目标是确定调节 RGC 的信号级联 IR后坏死性凋亡。根据我们已发表的数据、初步研究和已发表的文献，我们提出了 IR诱导RGC坏死性凋亡的分子机制。我们认为 IR 诱导的 RGC 中的 Tnf 信号传导促进正反馈回路的形成，以持续产生活性氧（ROS），由于 DNA 显着氧化，可促进聚 (ADP-核糖) 聚合酶 1 (Parp1) 过度激活损害。 RGC 中 Parp1 显着过度激活介导 ATP 耗竭，导致随后的能量消耗失败，导致细胞功能障碍并最终导致 RGC 膜完整性丧失（坏死）。我们将采用广泛的生化、分子和细胞生物学技术以及动物模型来在假设驱动的机制中验证所提出的 IR 诱导 RGC 坏死性凋亡的分子机制实验概述了以下具体目标：1) 检验 Tnf 信号传导促进 IR-的假设诱导RGC坏死性凋亡； 2) 检验IR诱导的RGC坏死性凋亡是通过形成促进的假设以 Tnf 信号依赖方式持续产生 ROS 的正反馈回路； 3）测试假设 RGC 坏死性凋亡是 IR 后 Parp1 过度激活导致 ATP 耗尽的结果。因此，因为 IR 的治疗受到限制，部分原因是缺乏对导致 IR 的分子事件的了解 RGC 死亡，对 IR 后 RGC 坏死性凋亡的更深入了解将带来新的治疗策略重要且难以治疗的病症。