Fibrinogen-mediated mechanisms of preterm infant brain injury

纤维蛋白原介导的早产儿脑损伤机制

• 批准号: 10201774
• 负责人: MARK A PETERSEN
• 金额: $ 20.01万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10201774
• 关键词: ACVR1 gene; Alzheimer' s Disease; Area; Binding; Biological Assay; Blood - brain barrier anatomy; Blood Proteins; Blood Vessels; Blood coagulation; Bone Morphogenetic Proteins; Brain; Cell Maturation; Cells; Cellular Assay; Chronic; Cicatrix; Co-Immunoprecipitations; Cytoplasmic Granules; Data; Deposition; Development; Developmental Disabilities; Environment; Event; Failure; Fibrinogen; Fibrinogen Receptors; Funding; Gene Expression Profile; Goals; Growth; Hemorrhage; Hypoxia; Impairment; In Vitro; Institutes; Integrins; Intraventricular Injections; Knockout Mice; Knowledge; Label; Ligands; Link; Mediating; Modeling; Molecular; Multiple Sclerosis; Mutant Strains Mice; Myelin; Neonatal Brain Injury; Nerve Degeneration; Nervous system structure; Neuraxis; Neurologic; Neurons; Oligodendroglia; Pathologic; Pathology; Pathway interactions; Pharmacology; Physicians; Premature Birth; Premature Infant; Preterm brain injury; Proteins; Reporter; Research; Risk; Role; Scientist; Signal Transduction; Signaling Protein; Site; Slice; Testing; Therapeutic; Time; Traumatic injury; Work; activin A; base; blood-brain barrier disruption; bone morphogenetic protein receptors; cell transformation; central nervous system injury; defined contribution; design; experience; in vivo; infant brain injury; inhibitor/antagonist; injured; intraventricular hemorrhage; myelination; neonatal brain; neonatal mice; nerve stem cell; nervous system disorder; neurodevelopment; neurogenesis; neuroinflammation; neurovascular; new therapeutic target; newborn brain injury; novel; oligodendrocyte progenitor; prevent; progenitor; progenitor system; receptor; repaired; response; skills; stem cells; therapeutic target; thrombotic; transcriptome; transcriptome sequencing; treatment strategy; two photon microscopy

PROJECT SUMMARY/ABSTRACT Preterm infant brain injury is often associated with blood-brain barrier (BBB) disruption and altered maturation of the central nervous system (CNS) progenitor cells required for normal brain development and myelination. The molecular signals in the injured microenvironment that inhibit CNS progenitor maturation are not fully known. Thus, no therapeutic options are available to prevent the developmental disabilities associated with preterm birth. BBB disruption alters the CNS progenitor niche by allowing blood proteins into the CNS. Fibrinogen, a blood coagulation protein, crosses a leaky BBB and is a key contributor to neuroinflammation, glial scar formation, neurodegeneration, and inhibition of CNS repair. We hypothesize that fibrinogen is a critical component of the microenvironment in preterm infant brain injury that inhibits CNS progenitor cell maturation to impair brain growth and myelination. Our preliminary studies show: (1) neonatal mice subjected to chronic hypoxia display prominent cerebellar pathology that includes fibrinogen deposition, myelination deficits, and impaired cerebellar growth; (2) Intraventricular injection of fibrinogen in neonatal mice disrupts cerebellar development in vivo; (3) Fibrinogen activates the bone morphogenetic protein (BMP) receptor activin A receptor type I (ACVR1) in oligodendrocyte progenitor cells (OPCs) to inhibit OPC maturation and myelination, (4) Fibrinogen inhibits neurogenesis from neuronal progenitor cells in vitro. Our specific aims will test our working model, whereby fibrinogen deposition after BBB disruption induces ACVR1-mediated BMP signaling in CNS progenitor cells to inhibit neurogenesis and myelination leading to abnormal neurodevelopment. In Aim 1, we will define the contribution of fibrinogen to preterm infant brain injury in vivo using fibrinogen mutant mice. In Aim 2, we will identify the cellular mechanisms that contribute to preterm infant brain injury at sites of fibrinogen deposition using in vivo two-photon microscopy (2PM). In Aim 3, we will determine the molecular mechanism of fibrinogen-induced activation of ACVR1 using in vitro binding and cellular assays. These studies will reveal the molecular link between BBB disruption and failure of CNS progenitor cell maturation in preterm infant brain injury. My goal is to become an independent physician- scientist and leader in the field of newborn brain injury. To continue my progress towards this goal, I will build upon the expertise of the Gladstone Institutes and UCSF to expand my research skills in the following areas: (1) in vivo 2PM to study the dynamic cellular responses to BBB disruption and fibrinogen deposition in the neonatal brain, (2) RNA-sequencing and transcriptome analysis to identify fibrinogen-mediated mechanisms of extrinsic inhibition, and (3) binding assays and inhibitor studies to discover novel fibrinogen receptors on CNS progenitor cells. The knowledge and experience gained from this proposal will allow me to compete for R01 funding focused on therapeutics that target the inhibitory microenvironment in preterm infant brain injury.

项目总结/摘要 早产儿脑损伤通常与血脑屏障（BBB）破坏和成熟改变有关 中枢神经系统（CNS）的祖细胞需要正常的大脑发育和髓鞘形成。 损伤微环境中抑制CNS祖细胞成熟的分子信号并不完全表达。 知道的因此，没有治疗选择可用于预防与以下相关的发育障碍： 早产。BBB破坏通过允许血液蛋白进入CNS来改变CNS祖细胞生态位。 纤维蛋白原是一种凝血蛋白，穿过渗漏的血脑屏障，是神经炎症的关键因素， 神经胶质瘢痕形成、神经变性和CNS修复抑制。我们假设纤维蛋白原是一种 早产儿脑损伤微环境中抑制CNS祖细胞的关键成分 成熟损害脑生长和髓鞘形成。我们的初步研究表明：（1）新生小鼠受 慢性缺氧显示突出的小脑病理，包括纤维蛋白原沉积，髓鞘形成 缺陷，以及小脑生长受损;（2）新生小鼠脑室内注射纤维蛋白原会破坏 （3）纤维蛋白原激活骨形态发生蛋白（BMP）受体激活素 在少突胶质细胞祖细胞（OPC）中抑制OPC成熟的I型受体（ACVR 1）， （4）纤维蛋白原抑制神经元前体细胞的神经发生。我们的具体目标将 测试我们的工作模型，其中血脑屏障破坏后纤维蛋白原沉积诱导ACVR 1介导的BMP CNS祖细胞中的信号传导以抑制神经发生和髓鞘形成，导致异常的 神经发育在目的1中，我们将确定纤维蛋白原在早产儿脑损伤中的作用 使用纤维蛋白原突变小鼠。在目标2中，我们将确定导致早产的细胞机制。 使用体内双光子显微镜（2PM）在纤维蛋白原沉积部位观察婴儿脑损伤。在目标3中，我们 使用体外结合确定纤维蛋白原诱导ACVR 1活化的分子机制， 细胞分析。这些研究将揭示血脑屏障破坏与中枢神经系统衰竭之间的分子联系 早产儿脑损伤中的祖细胞成熟我的目标是成为一名独立的医生- 新生儿脑损伤领域的科学家和领导者。为了继续朝着这个目标前进，我将建立 在格拉德斯通研究所和加州大学旧金山分校的专业知识，以扩大我在以下领域的研究技能： (1)在体内2PM研究动态细胞反应BBB破坏和纤维蛋白原沉积在 新生儿脑，（2）RNA测序和转录组分析，以确定纤维蛋白原介导的机制， 外源性抑制，以及（3）结合试验和抑制剂研究，以发现CNS上的新型纤维蛋白原受体 祖细胞从这个建议中获得的知识和经验将使我能够竞争R 01 资金集中在针对早产儿脑损伤抑制性微环境的治疗上。