Enhanced cellular therapy for neonatal stroke

项目摘要 新生儿中风是死亡和残疾的一个重要原因，由多种细胞死亡途径引起 和功能障碍的症状。对这一角色的认识不足 局部缺血-再灌注损伤是早期脑缺血最常见的原因， 中风血管生成和神经元再生发生在密切相关的，与旁分泌因子支持 神经元-内皮细胞相互作用对于修复至关重要。调节这种神经血管生态位可能是一种 是改善新生儿缺血性脑损伤预后的潜在靶点。基于细胞的疗法 已经成为CNS疾病的一种有希望的治疗方法，尽管修复机制已经被证明是有效的。 争议间充质干细胞（MSC）在血管形成中发挥作用，并分泌促血管生成因子。 生长因子，表达许多生长因子受体，并且可以优先分化成能够 在受伤后重建新血管。MSC治疗已显示出改善组织学和功能 缺血性损伤后，即使治疗延迟，但它只是部分修复。修改 MSC以增强对神经血管单位的影响的方式可能提供额外的益处。 我们的总体目标是确定延迟细胞治疗的再生和修复机制 通过关注受伤大脑的血管反应来治疗新生儿中风。在目标1中，我们将测试 假设MSC预暴露于EPO将增强血管生成和血管重塑， 新生大鼠局灶性缺血-再灌注损伤的发生率高于MSC或EPO单独治疗。在目标2中，我们将 阐明这种改良的细胞疗法通过使用多种技术在多大程度上调节长期修复 量化细胞命运、大体组织学和长期感觉运动和认知结果。在目标3中，我们 将定义特定下游信号通路对血管生成和缺血后修复的作用- 再灌注损伤和细胞治疗。这将确定关键的，可修改的途径， 血管生成在发育中的大脑和以下局灶性损伤，这可以进一步研究，以提高长期- 定期维修。我们的主要假设是，延迟用EPO预处理的MSC治疗将促进 血管生长和重塑，增加神经发生，并改善长期组织学和功能 新生儿中风后的结果。这将为早期脑梗死的常见原因提供一种晚期治疗选择。 损伤，诊断往往被延误。

PROJECT SUMMARY Neonatal stroke is an important cause of death and disability, resulting from multiple pathways of cell death and dysfunction that evolve over a prolonged period of time. There is insufficient knowledge regarding the role of angiogenesis in the response to focal ischemia-reperfusion injury that is the most common cause of early stroke. Angiogenesis and neuronal repopulation occur in close proximity, with paracrine factors supporting neuron-endothelial cell interactions that are critical for repair. Modulating this neurovascular niche may be a potential target for enhancing outcomes after ischemic brain injury in the newborn period. Cell-based therapies have emerged as a promising treatment for CNS disease, although the mechanism of repair has been controversial. Mesenchymal stem cells (MSC) play a role in vascular formation and secrete pro-angiogenic factors, express a number of growth factor receptors, and may preferentially differentiate into cells capable of building new blood vessels after injury. MSC treatment has been shown to improve histological and functional outcomes after ischemic injury, even when therapy was delayed, but it is only partially reparative. Modifying MSC in a way that enhances effects on the neurovascular unit may provide additional benefit. Our overall objective is to determine the mechanism of regeneration and repair with delayed cellular therapy for neonatal stroke by focusing on the vascular response in the injured brain. In Aim 1, we will test the hypothesis that MSC pre-exposed to EPO will enhance angiogenesis and vascular remodeling following neonatal focal ischemia-reperfusion injury in the rat more than MSC or EPO therapy alone. In Aim 2, we will clarify to what extent this modified cellular therapy modulates long-term repair by using a number of techniques to quantify cell fate, gross histology and long-term sensorimotor and cognitive outcomes. Finally, in Aim 3, we will define the roles of specific downstream signaling pathways on angiogenesis and repair following ischemia- reperfusion injury and cellular therapy. This will determine critical, modifiable pathways important for angiogenesis in the developing brain and following focal injury, which can be further studied to enhance long- term repair. Our primary hypothesis is that delayed treatment with MSC pretreated with EPO will promote vascular growth and remodeling, increase neurogenesis, and improve long-term histological and functional outcomes after neonatal stroke. This will provide a late treatment option for a common cause of early brain injury, where diagnosis is often delayed.