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Neuronal Regulation of Vascular Development and Maturation in the Retina

视网膜血管发育和成熟的神经元调节

基本信息

批准号：
10630239
负责人：
Dritan Agalliu
金额：
$ 45.18万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
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 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10630239
关键词：
Address Affect Angiogenic Factor Basement membrane Blood Vessels Blood-Retinal Barrier Caveolae Cell Death Cell Proliferation Cells Data Defect Development Endothelial Cells Functional disorder GLAST Protein Genetic Glutamate Receptor Glutamates Growth Knowledge Measures Mediating Membrane Proteins Metabolic Molecular Mouse Strains Muller&apos s cell Mus Mutant Strains Mice Nerve Degeneration Neuroglia Neurons Neurotransmitters PECAM1 gene Pathway interactions Permeability Phase Phenotype Photoreceptors Process Regulation Retina Retinal Diseases Role Signal Pathway Signal Transduction Synapses Synaptic Cleft Testing Tight Junctions Tracer Transcript Transducers Transforming Growth Factor beta VEGFA gene angiogenesis aquaporin 4 beta catenin cholinergic cholinergic neuron excitotoxicity extracellular genetic approach glutamatergic signaling imaging approach neurovascular unit notch protein novel novel therapeutic intervention pharmacologic postnatal response retinal angiogenesis sensor single-cell RNA sequencing transcriptomics uptake

项目摘要

PROJECT SUMMARY Reciprocal interactions among neuronal, glial and vascular-associated cells are critical for proper vascular development (angiogenesis) and maturation [establishment of the blood-retina barrier (BRB)] in the early postnatal (P) retina. Although neuronal or glial cell-derived signals that promote angiogenesis and BRB formation2 are emerging, we do not understand how neuronal synaptic activity, in general, and which specific neurotransmitter(s), in particular, contribute to these processes. Nor do we know whether neurotransmitters act directly on endothelial cells (ECs) or indirectly via Müller glia. The superficial vascular plexus develops from P1-P9 during the spontaneous cholinergic wave. In contrast, the deep vascular plexus development and BRB maturation (P10-P14) occur at the end of the cholinergic wave and the onset of both spontaneous and photoreceptor-mediated glutamatergic activity. Transient pharmacological blockade of cholinergic waves delays deep plexus angiogenesis and BRB maturation; however, the role of extracellular glutamate in these processes is unknown. In preliminary studies, we have used two mouse strains to assess the effects of glutamate release on retinal angiogenesis and BRB maturation: a) Vglut1 -/- mice that lack glutamate release in the synaptic cleft and b) Gnat1-/- mice that constitutively release glutamate in the synapse. We have found that neuronal activity-dependent glutamate release is a positive regulator of deep plexus angiogenesis and BRB maturation. These effects are mediated by induction of Norrin in Müller glia and Norrin/b-catenin pathway activation in ECs. Based on these preliminary data, we hypothesize that extracellular glutamate levels are sensed by Müller cells, which in turn operate as transducers to induce expression of angiogenic and BRB- forming factors and promote deep plexus angiogenesis and BRB maturation. We will test this hypothesis in three aims. First, we will examine how modulation of extracellular glutamate levels [Vglut1-/- mice (no glutamate release) and Gnat1-/- mice (high glutamate release)] regulates retinal angiogenesis and structural and functional BRB integrity in the developing retina. We will also examine how glutamatergic and cholinergic activity interact to regulate these processes. Next, we will test whether Müller cells sense extracellular glutamate and respond by inducing expression of angiogenic and barriergenic factors. We will examine Müller cell responses and Norrin expression (an angiogenesis factor) by Müller cells in mice deficient for glutamate release by neurons or uptake by Müller glia. Finally, we will test if activation of Norrin/b-catenin signalling, that promotes angiogenesis and BRB maturation, in ECs can rescue deficits of Vglut1-/- mice. Overall, our studies will provide a novel mechanistic understanding of how glutamatergic synaptic activity regulates development of the deep vascular plexus and BRB maturation in the developing retina and elucidate how glutamate excitotoxicity may affect blood vessels in neurodegenerative retinal diseases.

项目摘要神经元、神经胶质细胞和血管相关细胞之间的相互作用对于正常的血管形成至关重要。早期的发育（血管生成）和成熟[血-视网膜屏障（BRB）的建立] 出生后（P）视网膜。虽然神经元或神经胶质细胞来源的信号，促进血管生成和BRB 形成2正在出现，我们不了解神经元突触活动，一般来说，神经递质尤其有助于这些过程。我们也不知道神经递质是否直接作用于内皮细胞（EC）或通过Müller胶质细胞间接作用。浅表血管丛由 P1-P9在自发胆碱能波期间。相反，深血管丛的发育和BRB 成熟（P10-P14）发生在胆碱能波的结束和自发和自发波的开始。光感受器介导的光致发光活性。胆碱能波的瞬时药物阻断延迟深丛血管生成和BRB成熟;然而，细胞外谷氨酸在这些中的作用，过程是未知的。在初步研究中，我们使用了两种小鼠品系来评估谷氨酸释放对视网膜血管生成和BRB成熟的影响：a）在视网膜血管生成和BRB成熟中缺乏谷氨酸释放的VEGF 1-/-小鼠，突触间隙和B）在突触中组成性释放谷氨酸的Gnat 1-/-小鼠。我们发现神经元活性依赖性谷氨酸释放是深丛血管生成和BRB的正调节因子成熟这些作用是通过诱导Müller胶质细胞中的Norrin和Norrin/b-catenin途径介导的在EC中激活。基于这些初步数据，我们假设细胞外谷氨酸水平是由Müller细胞感知，Müller细胞反过来作为传感器诱导血管生成和BRB的表达，形成因子，促进深丛血管生成和BRB成熟。我们将测试这个假设，三个目标。首先，我们将研究细胞外谷氨酸水平的调节[VEGF 1-/-小鼠（无谷氨酸）]如何影响细胞外谷氨酸水平。释放）和Gnat 1-/-小鼠（高谷氨酸释放）]调节视网膜血管生成和结构，发育中的视网膜中的功能性BRB完整性。我们还将研究多巴胺能和胆碱能活动相互作用来调节这些过程。接下来，我们将测试Müller细胞是否感知细胞外谷氨酸和响应诱导表达血管生成和屏障形成因子。我们会检查穆勒谷氨酸缺乏小鼠Müller细胞的细胞反应和Norrin表达（血管生成因子）通过神经元释放或通过Müller胶质细胞摄取。最后，我们将测试Norrin/b-连环蛋白信号传导的激活，促进血管生成和BRB成熟，在EC中可以挽救VEGF 1-/-小鼠的缺陷。总的来说，我们的研究将提供一个新的机制了解如何神经元突触活动调节发展，深层血管丛和BRB成熟的发展视网膜，并阐明如何谷氨酸兴奋性毒性可影响神经变性视网膜疾病中的血管。