Role of Arginase 1 in Retinal Ischemia Reperfusion Injury

精氨酸酶 1 在视网膜缺血再灌注损伤中的作用

• 批准号: 10828178
• 负责人: Abdelrahman Fouda
• 金额: $ 4.37万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10828178
• 关键词: ARG2 gene; Anabolism; Arginine; Blindness; Data; Diabetic Retinopathy; Disease; Enzymes; Genetic Transcription; Glaucoma; Goals; HDAC3 gene; Infiltration; Inflammation; Inflammatory; Inflammatory Response; Investigational Drugs; Knowledge; Laboratory Finding; Macrophage; Mediating; Mission; Mitochondria; Mus; Myelogenous; Myeloid Cells; NOS2A gene; Nitric Oxide; Nitric Oxide Synthase; Ornithine; Ornithine Decarboxylase; Oxidative Stress; Paper; Pathway interactions; Polyamines; Protein Isoforms; Publishing; Putrescine; Reperfusion Injury; Research Support; Retina; Retinal Diseases; Retinopathy of Prematurity; Role; Therapeutic; Translating; Up-Regulation; Vision Disorders; arginase; chromatin modification; inhibitor; ischemic injury; neuroprotection; neurovascular; neurovascular injury; new therapeutic target; novel; parent grant; protective effect; public health relevance; research study; retinal ischemia; vein occlusion

Abstract of the parent grant R00EY029373: Retinal ischemia is a major cause of vision loss in common retinal disease conditions including diabetic retinopathy, glaucoma, retinopathy of prematurity, and vein occlusion. This project aims to define the mechanisms of retinal ischemic injury and identify new therapeutic targets. We have previously demonstrated the involvement of the arginase enzyme in retinal neurovascular diseases. Arginase has two isoforms. Building upon the lab's finding that the mitochondrial isoform, arginase 2 (A2), has a deleterious role in retinal ischemia-reperfusion (IR) injury, we developed a project focusing on the neurovascular protective role of the cytosolic isoform arginase 1 (A1). Our recently published papers shows a neuroprotective role of A1 expression in myeloid cells. Arginase competes with nitric oxide synthase (NOS) for their common substrate L-arginine. Nitric oxide (NO) produced by inducible NOS (iNOS) causes neurovascular degeneration. We predict that A1 upregulation in myeloid cells limits iNOS-derived nitrative and oxidative stress and reduces inflammation through its downstream metabolites ornithine and putrescine. Putrescine is the precursor of polyamines and it is formed from ornithine by ornithine decarboxylase (ODC, the rate-limiting enzyme in polyamine biosynthesis). These metabolites have been shown to promote reparative myeloid cells through chromatin modification. In line with this, our preliminary data show that histone deacetylase (HDAC) 3 is increased in the absence of A1 in both IR-injured retinas and stimulated macrophages. HDAC3 is essential for macrophage inflammatory gene transcription and it has been shown to suppress A1 expression. Herein, We propose a novel suppressive effect of A1 on HDAC3. Our central hypothesis predicts that myeloid A1 protects against retinal IR injury through ODC-mediated suppression of HDAC3. We will be using mice with myeloid-specific deletion of A1, ODC and HDAC3, as well as the investigational drug, BCT-100 (a PEGylated form of arginase 1), together with primary macrophages isolation and treatment with inhibitors for HDAC3 or arginase downstream enzyme, ODC. Our goal is to achieve the following objectives: First) Determine the effect of manipulating the arginase pathway on myeloid cells infiltration / activation in retinal IR injury and the therapeutic potential of BCT- 100. Second) Describe the cross talk between the arginase pathway and HDAC3 and determine whether A1 in myeloid cells mediates its protective effect through suppression of HDAC3. Third) Determine the role of myeloid specific deletion of HDAC3 on macrophage inflammatory response and retinal neurovascular injury.

家长补助金 R00EY029373 的摘要： 视网膜缺血是常见视网膜疾病中视力丧失的主要原因，包括 糖尿病视网膜病变、青光眼、早产儿视网膜病变和静脉阻塞。该项目旨在 明确视网膜缺血性损伤的机制并确定新的治疗靶点。 我们之前已经证明精氨酸酶参与视网膜 神经血管疾病。精氨酸酶有两种同工型。基于实验室的发现 线粒体亚型精氨酸酶 2 (A2) 在视网膜缺血再灌注 (IR) 中具有有害作用 损伤，我们开发了一个项目，重点关注细胞质的神经血管保护作用 同工型精氨酸酶 1 (A1)。我们最近发表的论文显示了 A1 的神经保护作用 在骨髓细胞中表达。精氨酸酶与一氧化氮合酶 (NOS) 竞争它们的共同点 底物L-精氨酸。诱导型一氧化氮合酶 (iNOS) 产生的一氧化氮 (NO) 会导致神经血管疾病 退化。我们预测骨髓细胞中 A1 的上调限制了 iNOS 衍生的硝化和 氧化应激并通过其下游代谢物鸟氨酸和减少炎症 腐胺。腐胺是多胺的前体，由鸟氨酸通过鸟氨酸形成 脱羧酶（ODC，多胺生物合成中的限速酶）。这些代谢物 已被证明可以通过染色质修饰促进骨髓细胞的修复。符合 我们的初步数据表明，组蛋白脱乙酰酶 (HDAC) 3 在缺乏 A1 存在于红外线损伤的视网膜和刺激的巨噬细胞中。 HDAC3 对于巨噬细胞至关重要 炎症基因转录，并​​已被证明可以抑制 A1 表达。在此，我们 提出 A1 对 HDAC3 的新抑制作用。我们的中心假设预测骨髓细胞 A1 通过 ODC 介导的 HDAC3 抑制来防止视网膜 IR 损伤。我们将会 使用具有 A1、ODC 和 HDAC3 骨髓特异性缺失的小鼠，以及研究中的 药物 BCT-100（精氨酸酶 1 的聚乙二醇化形式），以及初级巨噬细胞分离 以及用 HDAC3 或精氨酸酶下游酶 ODC 抑制剂进行治疗。我们的目标是 实现以下目标：第一）确定操纵精氨酸酶途径的效果 视网膜 IR 损伤中骨髓细胞浸润/激活的影响以及 BCT- 的治疗潜力 100. 第二）描述精氨酸酶途径和 HDAC3 之间的串扰并确定 骨髓细胞中的 A1 是否通过抑制 HDAC3 介导其保护作用。第三） 确定 HDAC3 的骨髓特异性缺失对巨噬细胞炎症反应的作用 和视网膜神经血管损伤。