How does the fibrotic scar regulate repair following neuroinflammation?

项目摘要 多发性硬化症(MS)是一种中枢神经系统炎症性疾病，在这种疾病中，身体的免疫 系统攻击包围和隔离神经元轴突的髓鞘。在许多情况下，这种髓鞘 不被少突胶质细胞谱系细胞修复会导致长期残疾。关于为什么髓磷脂 没有修复的是有一种物理屏障阻止少突胶质细胞系细胞与 轴突和修复受损的髓鞘。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。疤痕由一层由反应性神经性瘢痕组成的外部胶质疤痕组成。 星形胶质细胞和由细胞外基质蛋白组成的内纤维疤痕。已经对胶质瘢痕进行了研究 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 纤维性疤痕的特征。在多发性硬化症中，胶质瘢痕也有特征，并报告了人类组织的纤维化，但 纤维性瘢痕的作用还没有被研究过。在神经炎性疾病中检测纤维化瘢痕的存在 损伤，用实验性自身免疫性脑脊髓炎(EAE)诱导小鼠，导致 神经炎性脱髓鞘病变的形成和广泛纤维化的小鼠模型 疤痕出现在症状出现几个月后残留的皮损组织中，源于 表达胶原的成纤维细胞的增殖。关于纤维性瘢痕在其中所起的作用，我们一无所知。 神经炎性损伤形成后的修复和激活疤痕形成的信号。这样做的目的是 项目是确定纤维性瘢痕在神经炎性损伤形成后修复中的作用，以及 提示其形成的分子机制，希望确定潜在的治疗方法来操纵 活体内的伤疤。需要检验的假设是，EAE诱导后形成的纤维性瘢痕防止了 纤维化细胞通过转化生长因子β途径的激活修复和形成。第一，瘢痕在EAE体内修复中的作用 将通过消融分裂的纤维细胞来防止纤维瘢痕的形成 在EAE诱导后。为了确定转化生长因子β途径的激活是否对瘢痕形成是必要的，成纤维细胞- 特定的Cre小鼠品系将被用于有条件地敲除转化生长因子β途径的关键信号基因 伤疤的形成。此外，研究转化生长因子β信号对细胞增殖、胶原合成的调节作用。 而中枢神经系统成纤维细胞的迁移、重组转化生长因子β和通路抑制剂将被添加到体外原代培养的 细胞模型。

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.