Acute brain injury and blood-brain barrier dysfunction in cerebral malaria (ABC)

摘要 脑型疟疾(CM)是恶性疟原虫感染引起的急性神经系统并发症。 临床表现为无法唤醒的昏迷。在CM中，几种致病机制相互作用，导致 在四分之一的幸存儿童中观察到典型的神经认知后遗症。感染的红细胞 脑微血管系统中的隔离导致广泛的炎症，内皮细胞激活， 缺氧/缺血损伤、血糖异常、溶血和细胞损伤，导致血脑屏障(BBB) 功能障碍，这可能会相互作用，导致脑损伤。我们发现升高的tau和其他标记物 在CM幸存者中，血液循环中神经元的损伤和相关的持续性神经功能障碍是增加的。 此外，这些脑损伤标志物与参与CM发病机制的因素有关，包括 血糖异常、细胞损伤和内皮/血脑屏障功能障碍。目前尚不清楚的是 红细胞内寄生虫局限于血管间隙，可在不越过血脑屏障的情况下对神经元造成损伤。 因此，迫切需要进行机械论研究，以定义参与 CM的发病机制导致血脑屏障功能障碍和神经元损伤。动物和体外血脑屏障模型已经被 促进我们对CM发病机制的了解的关键，但现有模型的局限性包括：1)物种间 非恶性疟动物模型的可变性，2)缺乏关键成分的内皮单层的使用 脑实质，3)依赖永生化或原代脑微血管内皮细胞(BMECs) 生理上相关的阻隔特性和/或遭受批次之间的可变性。要克服这些障碍 考虑到局限性，我们开发了一种多细胞BBB模型，由人类来源的BMECs、神经元和 星形胶质细胞。使用我们的多细胞血脑屏障模型，我们建议研究神经元损伤并检查 CM发病相关因素与脑损伤生物标志物的相互作用我们将验证 我们的脑损伤生物标记物数据对12岁时接受认知障碍测试的CM儿童进行了跟踪调查。 月份。我们假设IES与BMECs的隔离导致BBB功能障碍和随后的 葡萄糖供应减少和细胞损伤标志物乳酸脱氢酶(LDH)的释放导致 神经元损伤，这是临床CM患者持续性神经功能障碍的预测因素。我们的假设将通过以下方式进行检验 具体目的如下：1)评估缺糖、细胞损伤和血管内皮细胞的影响 体外人源性多细胞血脑屏障模型中神经元损伤的功能障碍，以及2)小组的评估 脑损伤生物标志物在临床CM中作为神经功能障碍的预测因子。完成后，这项工作将建立 我们的人源性多细胞血脑屏障模型作为研究神经元潜在机制的标准 损伤，我们已经证明它是临床CM中持续性神经功能障碍的预测因子。我们的型号有 通过促进新的治疗靶点的研究来改变体外CM神经病理学领域的潜力 预防或减少儿童CM后未来的神经功能障碍。

ABSTRACT Cerebral malaria (CM) is an acute neurologic complication of infection with Plasmodium falciparum malaria that presents clinically as an unarousable coma. In CM, several pathogenic mechanisms interact to cause the characteristic neurocognitive sequelae observed in a quarter of surviving children. Infected erythrocytes sequester in the brain microvasculature leading to widespread inflammation, endothelial activation, hypoxic/ischemic injury, glucose abnormalities, hemolysis and cellular injury, resulting blood-brain barrier (BBB) dysfunction, which may interact to cause brain injury. We have found that elevated tau and other markers of injury to neurons are elevated in blood circulation and associated persistent neurodisability in survivors of CM. Further, these brain injury markers are associated with factors involved in the pathogenesis of CM, including glucose abnormalities, cellular injury, and endothelial/BBB dysfunction. What remains unclear is how intraerythrocytic parasites confined within the vascular space, cause injury to neurons without crossing the BBB. Thus, there is a critical need for mechanistic studies to define interactions between factors involved in the pathogenesis of CM leading to BBB dysfunction and neuronal injury. Animal and in-vitro BBB models have been key in advancing our knowledge of CM pathogenesis but limitations of existing models include: 1) interspecies variability of non-falciparum animal models, 2) use of endothelial monolayers that lack key components of the brain parenchyma, 3) reliance on immortalized or primary brain microvascular endothelial cell (BMECs) that lack physiologically relevant barrier properties and/or suffer from batch-to-batch variability. To overcome these limitations, we have developed a multicellular BBB model comprised of human-derived BMECs, neurons, and astrocytes. Using our multicellular BBB model, we propose to investigate neuronal injury and examine interactions between factors involved in CM pathogenesis and biomarkers of brain injury. And we will validate our brain injury biomarker data in a follow-up cohort of children with CM tested for cognitive impairments at 12- months. We hypothesize that sequestration of IEs to BMECs results in BBB dysfunction and the subsequent decrease of glucose availability and release of cellular injury marker lactate dehydrogenase (LDH) causing neuronal injury, which is a predictor of persistent neurodisability in clinical CM. Our hypothesis will be testing by the following specific aims: 1) evaluation of the impact of glucose deprivation, cellular injury, and endothelial dysfunction on neuronal injury in an in vitro human-derived multicellular BBB model, and 2) evaluation of a panel of brain injury biomarkers as predictors of neurodisability in clinical CM. Upon completion, this work will establish our human-derived multicellular BBB model as the standard for investigating mechanisms underlying neuronal injury, which we have shown to be a predictor of persistent neurodisability in clinical CM. Our model has the potential to transform the field of in-vitro CM neuropathology by facilitating research into new therapeutic targets to prevent or reduce future neurodisability after pediatric CM.