Cellular Behaviors of Perivascular Fibroblasts in Cerebral Ischemia

脑缺血时血管周围成纤维细胞的细胞行为

基本信息

批准号：
10320730
负责人：
Stephanie Bonney
金额：
$ 6.64万
依托单位：
SEATTLE CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10320730
关键词：
Address Animals Apoptosis Behavior Biochemical Blood - brain barrier anatomy Blood Vessels Blood capillaries Brain Brain Injuries Caliber Cells Cerebral Ischemia Characteristics Cicatrix Development Event Extracellular Matrix Fibroblasts Fibrosis Future Goals Health Hypoxia Infarction Inflammation Inflammatory Response Injury Ischemic Stroke Knowledge Label Lesion Location Maintenance Mitogens Molecular Profiling Morphology Mus Nerve Regeneration Neuraxis Nutrient Optics Oxygen Pathway interactions Patient-Focused Outcomes Patients Pericytes Pharmacology Platelet-Derived Growth Factor Play Population Process Proliferating Recovery Recovery of Function Regenerative capacity Resolution Rogaine Role Signal Transduction Site Stroke Testing Therapeutic Time Tissues Transgenic Mice Vascular System Work arteriole base blood-brain barrier function cell behavior cell type central nervous system injury cerebrovascular design experimental study healing imaging approach imaging study improved in vivo in vivo imaging in vivo two-photon imaging migration necrotic tissue neuron loss post stroke regeneration following injury regenerative relating to nervous system response targeted treatment therapy development tissue injury two photon microscopy venule wound healing

项目摘要

Regaining brain function is crucial to improve patient recovery following stroke. An ischemic event in the brain limits oxygen and nutrient supply resulting in neuronal cell death and a robust inflammatory response. Following clearance of the necrotic tissue the lesion undergoes a wound healing processes ultimately resulting in the formation of a fibrotic scar. The fibrotic scar impedes neuronal regeneration thus impacting recovery and function of the damaged tissue. The contributing cell types that promote fibrotic scar formation following stroke are poorly understood. Addressing these gaps in knowledge will allow us to identify the pro-fibrotic cell types and better poise us for testing mechanisms that contribute to fibrosis following CNS injury. Understanding these important aspects of stroke could provide a potential for developing therapeutics aimed at limiting scar formation and supporting neuronal regeneration following stroke. Recent studies have identified Pdgfrβ-expressing cells as the potential pro-fibrotic cell type following CNS injury. The identity of the Pdgfrβ-expressing cells, however, is not clear. Strong evidence points to Pdgfrβ- expressing perivascular fibroblasts (PVFs) as major contributors to the fibrotic scar. On the other hand, Pdgfrβ+ pericytes are also suggested to promote fibrotic scar formation. However, pericytes are generally sensitive to hypoxia and inflammation and likely undergo apoptosis following CNS injury. Based on this, I hypothesize that perivascular fibroblasts are a unique population of perivascular cells in the brain and significantly contribute to the fibrotic scar following cerebral ischemia. Using in vivo two-photon microscopy to simultaneously visualize pericytes and PVFs I will test this hypothesis in two distinct aims. In Aim 1, I will study the topological relation of PVFs to pericytes along the cerebrovascular network, define their morphological characteristics, and test the role of PVFs in vascular stability in the healthy brain. In Aim 2, I will characterize the cellular behaviors of PVFs and pericytes following cerebral ischemia to determine which cell type substantially contributes to the fibrotic scar. I will also pharmacologically inhibit PDGF signaling to determine if this pathway plays a significant role in the activation of PVFs during cerebral ischemia. Together these studies will help to elucidate the pro-fibrotic cell type following stroke in animals and determine if PVFs are important for vascular stability in the healthy brain.

恢复大脑功能对于改善中风后患者的康复至关重要。大脑缺血会限制氧气和营养供应，导致神经元细胞死亡和强烈的炎症反应，坏死组织清除后，病变会经历伤口愈合过程。纤维化疤痕的形成会阻碍神经元再生，从而影响受损组织的恢复和功能，但人们对促进中风后纤维化疤痕形成的细胞类型知之甚少。使我们能够识别促纤维化细胞类型，并更好地测试导致中枢神经系统损伤后纤维化的机制，了解中风的这些重要方面可以为开发旨在限制中风后疤痕形成和支持神经元再生的治疗方法提供潜力。最近的研究已确定 Pdgfrβ 表达细胞是中枢神经系统损伤后潜在的促纤维化细胞类型，但是，尚不清楚 Pdgfrβ 表达细胞的身份。血管周围成纤维细胞（PVF）是纤维化疤痕的主要贡献者，另一方面，Pdgfrβ+周细胞也被认为促进纤维化疤痕形成。然而，周细胞通常对缺氧和炎症敏感，并且可能在中枢神经系统损伤后发生细胞凋亡。因此，我认为血管周围成纤维细胞是大脑中血管周围细胞的独特群体，对脑缺血后的纤维化疤痕有显着贡献。体内双光子显微镜同时可视化周细胞和 PVF 我将在两个不同的目标中测试这一假设，在目标 1 中，我将研究 PVF 与周细胞沿脑血管网络的拓扑关系，定义它们的形态特征，并测试其作用。 PVF 在健康大脑血管稳定性中的作用在目标 2 中，我将描述脑缺血后 PVF 和周细胞的细胞行为，以确定哪些情况。我还将逻辑上抑制 PDGF 信号传导，以确定该通路是否在脑缺血期间的 PVF 激活中发挥重要作用，这些研究将有助于阐明中风后的促纤维化细胞类型。动物并确定 PVF 对健康大脑的血管稳定性是否重要。