Microbial-mediated blood-brain barrier development at the intersection of the gut-brain axis

项目摘要/摘要 血脑屏障(BBB)是控制循环血液之间相互作用的直接界面。 和中枢神经系统(CNS)。目前的肠道-脑轴研究表明，肠道和大脑之间的联系 微生物组和中枢神经系统发挥作用，但在很大程度上绕过了决定是否或什么微生物的血脑屏障 介质将进入中枢神经系统，对大脑功能产生影响。这些潜在影响的另一个方面 循环微生物因子是直接影响血脑屏障成分的因素。早产代表着越来越多的 长期的早产相关神经发育缺陷给医疗保健和社会带来的负担。 败血症、坏死性小肠结肠炎和围产期脑损伤等疾病都与高风险相关。 神经发育不良的结果，并与生物失调有关，从而使新生儿 微生物组是改善发展成果的目标.在这项提案中，我们的目标是测试总体 与早产相关的早期生物失调导致血脑屏障受损的假说 发育和功能，并对大脑发育和神经结果有长期影响。我们 将利用已建立的灵芝小鼠转基因方法作为实验平台。三 将利用与临床相关的微生物群落来评估血脑屏障的发展。 从出生前到出生后早期的肠道微生物区系：1)低早产儿的群落 出生后发育；2)母亲确诊为绒毛膜羊膜炎的早产儿的社区；3) 社区从足月健康的婴儿开始。此外，嗜酸乳杆菌和嗜酸乳杆菌的组合 婴儿双歧杆菌将按母体给药，作为优化血脑屏障发育和 功能。血脑屏障完整性，血脑屏障紧密连接的时间发展，组件和运输系统 表型标记将被检查。此外，神经元发育和白质成熟在 将调查不同的发展阶段以及青少年时期的行为。16S rRNA基因 对人类捐赠者、转基因水坝和后代的粪便样本进行测序将用于 确定微生物群落的特征，以确定与BBB相关的不同微生物种类/模式 功能变化。这项研究的新知识将是1)证明早产微生物 社区可以影响BBB的发育和神经学结果，从胚胎阶段到 出生后阶段；2)在血脑屏障成分中确定目标(S)，其中微生物介体具有 具体影响；3)确定与血脑屏障发育和功能相关的微生物标记。此外， 通过测试益生菌在改善微生物组特征、血脑屏障功能和神经学方面的效果 结果，我们将确定一种基于微生物组的治疗方案，可用作潜在的有效方案 减少早产儿神经发育缺陷的策略。

PROJECT SUMMARY/ABSTRACT The blood-brain barrier (BBB) is the direct interface that governs the interaction between the circulating blood and central nervous system (CNS). Current gut-brain axis research has made the association between the gut microbiome and CNS functions but largely bypasses the BBB which determines whether or what microbial mediators will enter CNS to have impacts on brain functions. Another aspect of the potential impacts of these circulating microbial factors is the direct impact on BBB components. Preterm birth represents an increasing burden for healthcare and society due to long term prematurity-associated neurodevelopmental deficits. Morbidities such as sepsis, necrotizing enterocolitis, and perinatal brain injuries are all associated with high risk for poor neurodevelopmental outcomes and have been associated with dysbiosis thus making the neonatal microbiome a target to improve developmental outcomes. In this proposal, we aim to test the overall hypothesis that early dysbiosis associated with preterm birth contributes to compromised blood-brain barrier development and functions, and has long term effects on brain development and neurological outcomes. We will utilize an established gnotobiotic mouse transfaunation method as the experimental platform. Three clinically relevant microbial communities will be utilized to evaluate BBB development under the influence of gut microbiota from prenatal stages to the early postnatal period: 1) Communities from preterm infants with low postnatal growth; 2) Communities from preterm infants born to a mother with confirmed chorioamnionitis; 3) Communities from full term healthy infants. In addition, the combination of Lactobacillus acidophilus and Bifidobacterium infantis will be maternally administrated as a strategy to optimize BBB development and function. BBB integrity, temporal development of BBB tight junction, components and transporter systems with phenotypical markers will be examined. Furthermore, neuronal development and white matter maturation at different developmental stages will be investigated as well as behaviors at a juvenile age. 16S rRNA gene sequencing of fecal samples of human donors, the transfaunated dams and offspring will be used to characterize the microbial communities to determine the distinct microbial species/pattern associated with BBB functional changes. The novel knowledge from this study will be 1) demonstrating that preterm microbial communities can influence BBB development and neurological outcomes from the embryonic stage to the postnatal period; 2) identifying the target(s) within the BBB components where microbial mediators have specific effects; 3) identifying microbial markers associated with BBB development and functions. Furthermore, by testing the efficacy of probiotics in improving microbiome characteristics, BBB function and neurological outcomes, we will identify a microbiome-based therapeutic option that can be used as a potential effective strategy to reduce neurodevelopmental deficits in preterm infants.