Functional role of satellite glial cells in axon regeneration

卫星胶质细胞在轴突再生中的功能作用

基本信息

批准号：
10061654
负责人：
Valeria Cavalli
金额：
$ 45.37万
依托单位：
WASHINGTON UNIVERSITY
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：
2019-12-01 至 2022-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10061654
关键词：
Adult Affect Afferent Neurons Attention Axon Biological Models Biology Brain Candidate Disease Gene Cell Differentiation process Cells Coculture Techniques Communication Complex Cues Data Embryo Enzymes Ethers Fatty Acids Fatty-acid synthase Gene Expression Gene Expression Profile Generations Genes Genetic Genetic Transcription Goals Human Immunofluorescence Immunologic Impairment In Situ Hybridization Inflammation Injury Link Lipids Molecular Molecular Profiling Mus Natural regeneration Nerve Regeneration Neuraxis Neuroglia Neurons Nociception Pain Palmitic Acids Pathologic Peripheral Peripheral Nerves Peripheral Nervous System Diseases Phospholipids Physiology Plasmalogens Play Process Property Recovery of Function Regenerative capacity Regenerative response Research Research Proposals Role Schwann Cells Sensory Signal Pathway Signal Transduction Speed Spinal Ganglia Structure System Testing Time axon growth axon injury axon regeneration base central nervous system injury chemotherapy chronic pain experimental study functional outcomes human model in vivo injured innovation lipid metabolism lipidomics live cell imaging mature animal mouse model nerve injury nerve repair nervous system disorder neuronal cell body novel marker novel therapeutics painful neuropathy peripheral nerve regeneration regenerative repaired response satellite cell sciatic nerve injury single cell sequencing single-cell RNA sequencing virtual

项目摘要

ABSTRACT Identifying strategies to increase the speed and extent of axon regeneration is important for central nervous system injuries, where axon regeneration usually fails. In contrast, peripheral sensory neurons with cell body in dorsal root ganglia can switch to a regenerative state after axon injury to promote regeneration and functional recovery. Studies on the effect of nerve injury on sensory neurons have revealed multiple neuronal intrinsic signaling mechanisms that promote axon regeneration. However, virtually nothing is known about the contribution of satellite glial cells (SGC) that envelop the neuronal soma in the nerve repair process. A better understanding of the role of SGC is important and highly significant. In this proposal, we outline experiments to uncover the transcriptional changes elicited in SGC following nerve injury and establish the mechanisms by which SGC contribute to sensory neurons' regenerative abilities. SGC form a sheath that completely surround sensory neurons, resulting in each neuron together with its satellite cell sheath constituting a discrete functional unit. We know that SGCs are altered structurally and functionally under pathological conditions associated with chronic pain and communication between sensory neurons and SGC plays a critical role in nociception. Based on our preliminary studies, we have now reason to believe that SGC play a previously unrecognized role in peripheral nerve regeneration. We will reveal the transcriptional profile of SGC in response to nerve injury using single cell sequencing approaches and determine if SGC subtypes exist. We will use human DRG to determine the transcriptional profile of human SGC and their role in axon growth using co-culture approaches. These experiments will allow us to reveal if findings made in the mouse model system are predictive of the physiology of human neurons. We have also established a neuron-SGC co-culture system that allows us to visualize and quantify how SGC envelop sensory neuron soma and determine SGC's role in sensory axon growth and regeneration. Finally, we will build on our findings that SGC upregulate genes related to lipid metabolism after injury to test if de novo fatty acid synthesis in SGC affect gene expression and axon regeneration following nerve injury. We will focus on Fatty acid synthase (Fasn), the key enzyme in de novo fatty acid synthesis, which we found is upregulated in SGC after nerve injury. Fasn synthesizes palmitic acid, which is the substrate for the synthesis of more complex fatty acids, such as ether linked phospholipids (including plasmalogens). Plasmalogens are enriched in the brain and play important roles in cell signaling and differentiation and are implicated in neurological disorders. We will use genetic and lipidomics approaches to determine how lipid metabolism in SGC contribute to the axon regeneration process. Through these experiments, we will uncover the contribution of SGC and plasmalogens to nerve injury and their functional role in axon regeneration.

抽象的确定提高轴突再生速度和范围的策略对于中枢神经非常重要系统损伤，轴突再生通常失败。相反，具有细胞体的外周感觉神经元背根神经节在轴突损伤后可以切换到再生状态，以促进再生和功能恢复。神经损伤对感觉神经元影响的研究揭示了多种神经元促进轴突再生的内在信号机制。然而，人们对此几乎一无所知卫星胶质细胞（SGC）在神经修复过程中包裹神经元胞体的贡献。更好的了解 SGC 的作用非常重要且意义重大。在这个提案中，我们概述了实验揭示神经损伤后 SGC 引起的转录变化并建立机制 SGC 有助于感觉神经元的再生能力。 SGC 形成一个完全包围感觉神经元的鞘，导致每个神经元与它的卫星细胞鞘构成一个离散的功能单元。我们知道 SGC 的结构发生了改变在与慢性疼痛和感觉之间的交流相关的病理条件下发挥功能神经元和 SGC 在伤害感受中起着至关重要的作用。根据我们的初步研究，我们现在有理由相信 SGC 在周围神经再生中发挥着以前未被认识到的作用。我们将揭晓使用单细胞测序方法研究 SGC 响应神经损伤的转录谱确定是否存在 SGC 亚型。我们将使用人类 DRG 来确定人类的转录谱 SGC 及其在使用共培养方法的轴突生长中的作用。这些实验将使我们能够揭示是否小鼠模型系统中的发现可以预测人类神经元的生理学。我们还有建立了神经元-SGC 共培养系统，使我们能够可视化和量化 SGC 包膜的方式感觉神经元胞体并确定 SGC 在感觉轴突生长和再生中的作用。最后，我们将基于我们的发现，即 SGC 上调损伤后与脂质代谢相关的基因，以测试是否从头发生脂肪 SGC 中的酸合成影响神经损伤后的基因表达和轴突再生。我们将重点关注脂肪酸合酶 (Fasn) 是脂肪酸从头合成的关键酶，我们发现它在神经损伤后的SGC。 Fasn 合成棕榈酸，棕榈酸是合成更多物质的底物复杂的脂肪酸，例如醚连接的磷脂（包括缩醛磷脂）。缩醛磷脂丰富在大脑中，在细胞信号传导和分化中发挥重要作用，并与神经系统有关失调。我们将使用遗传和脂质组学方法来确定 SGC 中的脂质代谢如何有助于轴突再生过程。通过这些实验，我们将揭示 SGC 和缩醛磷脂对神经损伤及其在轴突再生中的功能作用。