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.

项目摘要视网膜缺血再灌注（IR）损伤是全球视觉障碍的常见原因，两者都影响患者的生活质量和功能状况。视网膜神经节细胞（RGC）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IR后发生坏死和凋亡。由于RGC凋亡是通过编程机制执行的，并且可以受到调节，因此非常关注被赋予了这种类型的细胞死亡。同时，RGC坏死的接收不够考虑因素，因为它被视为意外和不受管制的细胞事件。我们现在知道坏死，例如凋亡，可以通过编程机制执行。这种坏死细胞死亡的形式是称为坏死性。我们发表的数据和文献表明RGC坏死作用有助于IR诱导通过直接丧失RGC和相关炎症反应的诱导，视网膜损伤。因此，自从 RGC坏死作用是通过编程机制执行的，可以受到调节，这一研究领域是非常重视。然而，调节IR诱导的RGC坏死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的信号传导级联 IR后坏死性。根据我们发布的数据，初步研究和发表的文献，我们提出了一个 IR诱导的RGC坏死的分子机制。我们建议IR诱导的RGC中的TNF信号传导促进形成一个正反馈回路，以持续产生活性氧（ROS），由于明显的氧化DNA而促进聚（ADP-核糖）聚合酶1（PARP1）过度激活损害。 RGC中的显着PARP1过度激活介导ATP耗竭，导致随后的能量失败，导致细胞功能障碍，最终导致RGC膜完整性丧失（坏死）。我们将采用多种生化，分子和细胞生物学技术以及动物模型验证在假设驱动的机理中IR诱导的RGC坏死的拟议分子机制在以下特定目的中概述的实验：1）测试TNF信号促进IR-的假设诱导RGC坏死性； 2）检验以下假设，即通过形成促进IR诱导的RGC坏死作用以TNF信号依赖性方式进行持续ROS产生的阳性反馈回路； 3）测试假设RGC坏死性是IR后PARP1过度激活引起的ATP耗竭的结果。因此，由于对IR的治疗受到限制，部分原因是缺乏对分子事件的了解 RGC死亡，对IR后的RGC坏死病有更多的了解，将导致新的治疗策略重要且难以治疗状况。