Microglia Mediated Inflammation in the Diabetic Retina

小胶质细胞介导的糖尿病视网膜炎症

基本信息

批准号：
10460458
负责人：
Astrid E Cardona
金额：
$ 36.08万
依托单位：
UNIVERSITY OF TEXAS SAN ANTONIO
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10460458
关键词：
Acute Angiogenic Factor Anti-Inflammatory Agents Behavior Binding Blindness Blood Vessels Cell Adhesion Molecules Cell surface Cells Characteristics Chronic Clinical Deposition Diabetes Mellitus Diabetic Retinopathy Diabetic mouse Disease Endotoxemia Event Fibrin Fibrinogen Fractalkine Goals Human Hyperglycemia Immunotherapy Inflammation Inflammatory Integral Membrane Protein Interleukin-1 Knockout Mice Knowledge Laboratories Lesion Link Maintenance Mediating Membrane Microglia Modeling Mus Neuroglia Neurons Oxidative Stress Pathology Pathway interactions Peripheral Phenotype Play Precipitation Prevention Process Production Property Proteins Regulation Retina Retinal Diseases Retinal Ganglion Cells Role Signal Pathway Signal Transduction Single Nucleotide Polymorphism Testing Therapeutic Tissues Up-Regulation Variant Vascular Endothelial Cell Vascular Endothelial Growth Factors Vascular Permeabilities Wild Type Mouse adeno-associated viral vector cell injury chemokine cytokine design diabetic diabetic patient genetic approach insight mouse model neuron loss novel oxidative damage prevent receptor reconstitution recruit relating to nervous system response retinal damage systemic inflammatory response treatment strategy

项目摘要

Project Summary In the diabetic retina disruption of fractalkine (FKN) signaling induces fibrin(ogen) deposition, increased production of IL-1 by microglia, vascular and neuronal damage. But, how FKN and its receptor, CX3CR1, regulate microglia activation and retinal pathology is unknown. In humans, two single nucleotide polymorphisms in the CX3CR1 locus (hCX3CR1-I249/M280) that show defective binding to FKN, play a key role in inflammation during diabetes. Induction of diabetes in a mouse model expressing the human CX3CR1- I249/M280 revealed accelerated neuronal loss in the retina, and systemic inflammation caused microglial clustering and upregulation of pro-inflammatory cytokines. Thus, the FKN/CX3CR1 signaling pathway plays an under-appreciated role in diabetic retinopathy (DR), perhaps via inflammatory processes. However, there is a gap in knowledge regarding the exact relationship among FKN/CX3CR1 signaling, microglial activation and cell damage (neuronal and vascular) in a diabetic host in which hyperglycemia and repeated episodes of systemic inflammation occur. The central hypothesis is that FKN is neuroprotective in DR by blocking microglia activation and the subsequent vascular permeability and inflammatory changes that are characteristics of DR. The following specific aims will test the mechanism by which sustained microglial activation by fibrin(ogen) potentiates neuronal and vascular endothelial cell damage. Utilizing experimental mouse models of diabetes combined with systemic endotoxemia the following specific aims are proposed. Specific Aim 1. Determine the role of microglia in the initiation and progression of diabetic retinopathy. This aim will test the hypothesis that FKN binds to CX3CR1 polarizing microglia towards an anti- inflammatory pathway early in disease. Therefore, a) microglia depletion in diabetic mice at acute and chronic stages of disease, and b) peripheral fibrin(ogen) depletion will be used, to demonstrate that 1) dysregulated microglia in response to fibrin(ogen) induce pro-inflammatory actions and oxidative damage that contribute to neuronal damage and 2) that regulation of microglia activation can be harnessed to prevent vision loss. Specific Aim 2. Determine the neuroprotective effects of soluble FKN to mitigate microglia activation and rescue neuronal and vascular damage. FKN is expressed on neurons as a transmembrane protein, acting as a membrane-bound adhesion molecule (mFKN) or as a soluble protein (sFKN) upon cleavage from cell surfaces. Adeno-associated viral vectors will be used to express sFKN or mFKN in neurons to test the hypothesis that pathways that enhance FKN signaling via its soluble domain are neuroprotective and will prevent vision loss. Approaches will be implemented to also determine the synergistic effect of sFKN and anti- fibrin approaches to prevent vision loss in mice lacking CX3CR1 or expressing the human CX3CR1I249/M280 variant.

项目概要在糖尿病视网膜中，fratalkine (FKN) 信号的破坏会诱导纤维蛋白（原）沉积，增加小胶质细胞、血管和神经元损伤产生 IL-1 但是，FKN 及其受体 CX3CR1 是如何产生的。在人类中，调节小胶质细胞激活和视网膜病理学的两个单核苷酸尚不清楚。 CX3CR1 位点 (hCX3CR1-I249/M280) 中显示与 FKN 结合缺陷的多态性发挥着关键作用在表达人类 CX3CR1- 的小鼠模型中诱导糖尿病。 I249/M280显示视网膜神经元损失加速，全身炎症导致小胶质细胞因此，FKN/CX3CR1 信号通路发挥着重要作用。其在糖尿病视网膜病变 (DR) 中的作用尚未得到充分认识，可能是通过炎症过程实现的。关于 FKN/CX3CR1 信号传导、小胶质细胞激活和糖尿病宿主的细胞损伤（神经元和血管），其中高血糖和反复发作核心假设是 FKN 通过阻断小胶质细胞对 DR 具有神经保护作用。激活以及随后的血管通透性和炎症变化是 DR 的特征。以下具体目标将测试纤维蛋白（原）持续激活小胶质细胞的机制利用糖尿病实验小鼠模型增强神经元和血管内皮细胞损伤。结合全身性内毒素血症，提出以下具体目标。具体目标 1. 确定小胶质细胞在糖尿病发生和进展中的作用该目标将检验 FKN 与 CX3CR1 极化小胶质细胞结合以抗视网膜病变的假设。因此，a) 急性和慢性糖尿病小鼠的小胶质细胞耗竭。疾病阶段，以及 b) 将使用外周纤维蛋白（原）消耗，以证明 1) 失调小胶质细胞对纤维蛋白（原）的反应诱导促炎作用和氧化损伤，从而导致神经元损伤；2）可以利用小胶质细胞激活的调节来预防视力丧失。具体目标 2. 确定可溶性 FKN 减轻小胶质细胞激活的神经保护作用并挽救神经元和血管损伤 FKN 在神经元上表达为跨膜蛋白，作为膜结合粘附分子 (mFKN) 或在裂解后作为可溶性蛋白 (sFKN) 腺相关病毒载体将用于在神经元中表达 sFKN 或 mFKN 以测试假设通过其可溶性结构域增强 FKN 信号传导的途径具有神经保护作用，并且将将实施一些方法来确定 sFKN 和抗视力丧失的协同效应。纤维蛋白方法可预防缺乏 CX3CR1 或表达人类 CX3CR1I249/M280 的小鼠视力丧失变体。