CINC-1 as a modulator of blood-brain barrier integrity after neonatal stroke

越来越多的人认识到，出生时中枢神经系统的不成熟影响缺血性损伤和恢复；因此，显然需要制定适合年龄的干预策略。成熟的血脑屏障(BBB)可以精确控制进入或离开大脑的物质。在包括中风在内的许多脑部疾病中，血脑屏障的破坏是导致损伤的重要因素。新出现的数据表明，血脑屏障是在出生时发育起来的，在正常情况下功能有效，但尚不清楚它是如何在生命早期受到脑损伤的影响。我们最近在新生大鼠身上的数据表明，短暂性脑缺血后，血脑屏障对蛋白质的通透性得到保护，尽管细胞因子诱导的中性粒细胞趋化蛋白1(CINC-1)存在显著的瞬时积聚，但中性粒细胞的迁移被阻止。这与成人大脑形成鲜明对比，在成人大脑中，血脑屏障的破坏发生得很早，而且是由趋化因子·驱动的中性粒细胞向缺血再灌流组织的渗透所介导的。我们的目标是10个了解赋予抵抗的机制 新生儿脑缺血后早期血脑屏障的变化及通过研究CINC·L在中性粒细胞迁移和屏障完整性中的作用来进行保护。 因此，我们建议检验这一假说，即CINC-L通过在中风后迅速保持血脑屏障的完整性来保护新生儿的大脑。 我们将确定循环CINC-1是否在新生儿卒中后保护血脑屏障的完整性(目标1)和限制中性粒细胞的激活和迁移(目标2)。研究将在出生后第7天完成局灶性短暂性大脑中动脉(MCA)闭塞大鼠的研究，并在闭塞期间通过扩散加权MRT确定为损伤。 我们将使用几种实验方法，包括流动圆柱法， 系统性CINC·L水平或中性粒细胞水平受到操纵的动物的免疫组织化学、细胞因子复合和核磁共振成像。

It is increasingly recognized that the immaturity of the CNS at birth affects ischemic injury and recovery; thus there is an obvious need to develop age-appropriate strategies for intervention. The mature blood-brain barrier (BBB) allows precise control of substances that enter or leave the brain. In many brain diseases, including stroke, BBB breakdown is an important contributing factor to injury. Emerging data show that the BBB is developed by birth and functions effectively under normal conditions, bul il is unclear how it is affected by brain injury early in life. Our recent data in neonatal rats show that BBB permeability to proteins is preserved following transient cerebral ischemia, and neutrophil transmigration is halted despite the presence of marked transient accumulation of the cytokine-induced neutrophil chemoaUractant protein 1 (CINC-1). This is in stark contrast to the adult brain where disruption of the BBB occurs early and is mediated by chemokine·driven neutrophil infiltration into ischemic-reperfused tissue. Our goal is 10 understand the mechanisms that confer resistance of the BBB following early post-ischemia in neonates and contribu te to protection by studying the role of CINC·l in neutrophlilransmigralion and barrier integrity. We therefore propose to test the hypothesis that CINC-l protects neonatal brain by preserving blood-brain barrier integrity acutely after stroke. We will determine whether circulating CINC-1 protects BBB integrity (Aim 1) and limits neutrophil activation and migration (Aim 2) acutely after neonatal stroke. Studies will be accomplished in postnatal day 7 rats subjected to focal transient middle cerebral artery (MCA) occlusion and identified as injured by diffusion-weighted MRt during occlusion. We will use several experimental approaches, including flow cylometry, immunohistochemistry, cytokine multiplex, and MRi in animals with manipulated systemic CINC·l levels, or manipulated neutrophils.