Roles of Calprotectin in a mouse model of maternal immune activation

摘要 自闭症谱系障碍(Asd)是一种常见的神经发育障碍，目前缺乏基本的 治疗方法。为了开发有效的治疗策略，我们需要了解分子 ASD建立背后的机制。众所周知，怀孕期间的感染会增加 子代发生ASD的可能性；因此，我们一直使用母体免疫激活(MIA) ASD小鼠模型的建立。利用这个模型，我们发现TLR3配体多肌苷：多胞苷 (Poly(I：C))以及病毒可通过胎盘直接激活胎儿边界相关 胎脑脉络丛(CP)内巨噬细胞(BAMS)。此外，我们发现， TLR3-MIA增加CP中BAMS的数量，并增加其S100A8和S100A8的表达 S100A9，它们共同形成一种称为钙保护素的异源二聚体蛋白。由于增加了钙化保护 已知表达与慢性炎症条件有关，我们假设钙保护素 由CP区的BAMS分泌的可能以自分泌的方式增强炎症，还可能 以旁分泌方式干扰神经前体细胞的分化、迁移和增殖 胎儿脑室周围区域的细胞(NPC)。在这个提案中，我们将通过以下方式测试我们的假设 用ELISA法测定TLR3-MIA对脑脊液中钙保护素蛋白水平的影响(目标1)和 在我们的单核TLR3-MIA模型中，通过研究钙保护素如何影响鼻咽癌的动态平衡 RNA-seq(目标2)。如果我们的假设是正确的，这项工作将是朝着开发一种治疗方法迈出的第一步 以胎脑钙保护素为靶点治疗自闭症的策略。

Abstract Autism spectrum disorder (ASD) is a common neurodevelopmental disorder that currently lacks a fundamental approach to treatment. To develop an effective therapeutic strategy, we need to understand the molecular mechanism behind how ASD is established. It is known that infection during pregnancy increases the probability of offspring developing ASD; therefore, we have been using a maternal immune activation (MIA) model of ASD in mice. Using this model, we have found that the TLR3 ligand polyinosinic:polycytidylic acid (Poly(I:C)) as well as virus can pass through the placenta and directly activate fetal border-associated macrophages (BAMs) in the choroid plexus (CP) of the fetal brain. Furthermore, we have discovered that TLR3-MIA increases the number of BAMs in the CP as well as increases their expression of S100a8 and S100a9, which together forms a heterodimeric protein called calprotectin. Since increased calprotectin expression is known to associate with chronic inflammatory conditions, we hypothesize that calprotectin secreted from BAMs in the CP region may enhance inflammation in an autocrine manner and may also function in a paracrine manner to disrupt the differentiation, migration, and proliferation of neural progenitor cells (NPCs) in the periventricular area of the fetal brain. In this proposal, we will test our hypothesis by measuring calprotectin protein levels in the cerebrospinal fluid in response to TLR3-MIA by ELISA (Aim 1) and by investigating how calprotectin may influence NPC homeostasis in our TLR3-MIA model using single-nuclei RNA-seq (Aim 2). If our hypothesis is correct, this work will be a first step toward developing a therapeutic strategy for treating ASD by targeting calprotectin in the fetal brain.