How does the fibrotic scar regulate repair following neuroinflammation?

纤维化疤痕如何调节神经炎症后的修复？

• 批准号: 9759713
• 负责人: Cayce Elizabeth Dorrier
• 金额: $ 3.79万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759713
• 关键词: Ablation; Affect; American; Area; Astrocytes; Axon; Blood Vessels; Brain Injuries; Cell Lineage; Cell Proliferation; Cell model; Cells; Central Nervous System Diseases; Chronic; Cicatrix; Collagen; Cues; Disease; Disease Progression; Experimental Autoimmune Encephalomyelitis; Extracellular Matrix Proteins; Fibroblasts; Fibrosis; Ganciclovir; Genes; Goals; Growth; Histologic; Human; Immune; Immune system; In Vitro; Infiltration; Injury; Knock-out; Lead; Learning; Lesion; Molecular; Motor; Multiple Sclerosis; Multiple Sclerosis Lesions; Mus; Myelin; Myelin Sheath; Neuraxis; Neurons; Onset of illness; Outcome; Pathway interactions; Patients; Peripheral; Pharmaceutical Preparations; Play; Process; Production; Proliferating; Recombinants; Recovery; Reporting; Role; Signal Transduction; Simplexvirus; Site; Smad Proteins; Spinal Cord; Spinal cord injury; Symptoms; Testing; Therapeutic; Thymidine Kinase; Time; Tissues; Transforming Growth Factor beta; Trauma; Traumatic CNS injury; Up-Regulation; brain tissue; disability; human tissue; in vitro Model; in vivo; inhibitor/antagonist; injured; insight; migration; mouse model; myelination; neuroinflammation; novel therapeutics; oligodendrocyte lineage; prevent; remyelination; repaired; seal; single cell sequencing; therapeutic target; tissue regeneration; tissue repair; transcriptome sequencing

Project Summary Multiple sclerosis (MS) is a neuroinflammatory disease of the central nervous system in which the body’s immune system attacks the myelin sheath that surrounds and insulates the axons of neurons. In many cases this myelin is not repaired by oligodendrocyte lineage cells leading to long term disability. One hypothesis as to why myelin is not repaired is that there is a physical barrier preventing oligodendrocyte lineage cells from interacting with axons and repairing the damaged myelin. Following spinal cord injury, a scar forms around the site of trauma and seals off the injured and inflamed tissue. The scar consists of an outer glial scar made up of reactive astrocytes and an inner fibrotic scar made of extracellular matrix proteins. The glial scar has been studied extensively as a potential therapeutic target for CNS trauma, but much less is known about the origins and role of the fibrotic scar. In MS, the glial scar has also been characterized, and fibrosis in human tissue reported, but the role of a fibrotic scar has not been investigated. To test for the presence of a fibrotic scar in neuroinflammatory lesions, mice were induced with experimental autoimmune encephalomyelitis (EAE), which leads to the formation of neuroinflammatory demyelinated lesions and is used as a mouse model of MS. An extensive fibrotic scar was present in the lesioned tissue that remained for months following symptom onset and arose from the proliferation of collagen-expressing fibroblasts. Nothing is known about the role this fibrotic scar plays in repair following neuroinflammatory lesion formation and the signals that activate scar formation. The goal of this project is to define the role of the fibrotic scar in repair following neuroinflammatory lesion formation and the molecular mechanisms that cue its formation, with the hopes of identifying potential therapeutics to manipulate the scar in vivo. The hypothesis to be tested is that the fibrotic scar that forms following EAE induction prevents repair and forms through TGFβ pathway activation in fibrotic cells. First, the role of the scar in EAE repair in vivo will be determined by preventing the fibrotic scar from forming through the ablation of dividing fibrotic cells following EAE induction. To determine if TGFβ pathway activation is necessary for scar formation, a fibroblast- specific Cre mouse line will be used to conditionally knockout key signaling TGFβ pathway genes prior to scar formation. Additionally, to study how TGFβ signaling regulates the proliferation, collagen production and migration of CNS fibroblasts, recombinant TGFβ and pathway inhibitors will be added to a primary, in vitro cell model.

项目概要 多发性硬化症 (MS) 是一种中枢神经系统的神经炎症性疾病，其中身体的免疫系统受到影响 系统攻击包围并隔离神经元轴突的髓鞘。在许多情况下，这种髓磷脂 不被少突胶质细胞谱系细胞修复，导致长期残疾。关于为什么髓磷脂 未修复的原因是存在物理屏障，阻止少突胶质细胞谱系细胞与 轴突并修复受损的髓磷脂。脊髓损伤后，创伤部位周围会形成疤痕 并封闭受伤和发炎的组织。该疤痕由外层神经胶质疤痕组成，该疤痕由反应性物质组成 星形胶质细胞和由细胞外基质蛋白组成的内部纤维化疤痕。神经胶质疤痕已被研究 广泛作为中枢神经系统创伤的潜在治疗靶点，但对其起源和作用知之甚少 纤维化疤痕。在多发性硬化症中，神经胶质疤痕也得到了表征，并且报道了人体组织中的纤维化，但是 纤维化疤痕的作用尚未得到研究。测试神经炎症中是否存在纤维化疤痕 损伤，小鼠被诱导实验性自身免疫性脑脊髓炎（EAE），这导致 神经炎性脱髓鞘病变的形成，并用作多发性硬化症的小鼠模型。广泛的纤维化 疤痕存在于病变组织中，在症状出现后持续数月，并且是由 表达胶原蛋白的成纤维细胞的增殖。关于这种纤维化疤痕的作用尚不清楚 修复神经炎症病变形成和激活疤痕形成的信号。此举的目标 该项目的目的是确定纤维化疤痕在神经炎症病变形成后修复中的作用以及 提示其形成的分子机制，希望能够找到潜在的治疗方法来操纵 体内的疤痕。待检验的假设是 EAE 诱导后形成的纤维化疤痕可防止 通过激活纤维化细胞中的 TGFβ 途径进行修复和形成。一、疤痕在体内EAE修复中的作用 将通过消融分裂的纤维化细胞来防止纤维化疤痕形成来确定 EAE诱导后。为了确定 TGFβ 通路激活是否是疤痕形成所必需的， 特定的 Cre 小鼠品系将用于在之前有条件地敲除关键信号转导 TGFβ 通路基因 到疤痕形成。此外，研究 TGFβ 信号如何调节增殖、胶原蛋白生成 CNS 成纤维细胞、重组 TGFβ 和途径抑制剂的迁移将被添加到初级、体外 细胞模型。