Using Oligo Array Analysis to Determine Genes of Importance in the Meninges and Associated Vasculature Function and their Sensitivity to Amphetamine Toxicity. Rattus norvegicus

Oligo array analysis with bioinformatics tools identified genes with very high expression levels in the meninges, arachnoid and pial membranes, and associated vasculatures (MAV) which are potentially important and unique to these tissues functional capabilities in rat. It was also determined if these genes were more sensitive to expression changes after a neurotoxic exposure to environmentally induced hyperthermia (EIH) or amphetamine (AMPH). Gene expression in the MAV was compared to the neuronal rich tissues of the striatum and parietal cortex. In controls, 1,116 genes differed by more than 5-fold when comparing MAV to both striatum and parietal cortex. Genes specifically identified with the blood-brain barrier (BBB) were also expressed at high levels indicating they may help form tight junctions in MAV. The more than 300 genes having a 15-fold or greater expression in MAV compared to striatum and cortex were deemed of potential uniqueness and importance to MAV function. Many of these genes are abundant in different types of epithelial tissue and function in binding, transport or metabolism of ions and solute, and may help MAV regulate cerebrospinal fluid. Many others with high expressions are involved in immune system function possibly serving to facilitate lymphocyte and macrophage trafficking in vasculature and cerebrospinal fluid. Genes in MAV with a higher expression (relative to striatum and cortex) were affected in greater numbers than expected by EIH and AMPH. Many expression increases evoked by AMPH and EIH in MAV relate to reactive oxidative stress and inflammation. However, AMPH induced more robust alterations in the expression of genes related to ion/solute transport (Slc15a1), lipid metabolism (Fst), bacterial infection (Lbp) and oddly pancreatitis (Reg3a, Reg3b). Expression of the BBB-related genes Sox18 and Cldn5 decreased in all regions with AMPH and EIH but even more so in MAV. Esam increased with AMPH in all regions while Angpt2 was only affected in striatum and parietal cortex. It is not known how these changes affect MAV, striatum or parietal cortex tight junction function/BBB and integrity. Overall design: Gene expression patterns in MAV were compared to two regions of brain (striatum and parietal cortex) to identify genes important to MAV function and determine whether their expressions were sensitive to a neurotoxic exposure to amphetamine.

本研究采用生物信息学工具开展寡核苷酸芯片（Oligo array）分析，在大鼠脑膜、蛛网膜与软脑膜及其相关脉管系统（meninges, arachnoid and pial membranes, and associated vasculatures，以下简称MAV）中鉴定出一批高表达基因，这类基因或对该组织独特的功能特性具有重要意义。本研究同时探究了这些基因在经历环境诱导性高热(EIH)或苯丙胺(AMPH)神经毒性暴露后，其表达变化是否更为敏感。研究比较了MAV与神经元富集组织（纹状体、顶叶皮层）的基因表达谱。对照组中，相较于纹状体与顶叶皮层，MAV中有1116个基因的表达差异超过5倍。血脑屏障(BBB)特异性相关基因同样在MAV中高表达，提示这些基因或参与构建MAV的紧密连接结构。相较于纹状体与皮层，MAV中表达量高出15倍以上的300余个基因，被认为是MAV功能特异性与重要性的潜在标志基因。其中多数基因在多种上皮组织中富集，功能涉及离子与溶质的结合、转运或代谢，或参与MAV对脑脊液的调控过程。另有大量高表达基因参与免疫系统功能，可能介导淋巴细胞与巨噬细胞在脉管系统及脑脊液中的迁移过程。相较于纹状体与皮层，MAV中表达量更高的基因受EIH与AMPH暴露影响的数量超出预期。AMPH与EIH诱导的MAV基因表达上调多与活性氧应激及炎症反应相关。但AMPH可更显著地改变与离子/溶质转运(Slc15a1)、脂质代谢(Fst)、细菌感染(Lbp)以及意外关联的胰腺炎相关基因(Reg3a、Reg3b)的表达。血脑屏障相关基因Sox18与Cldn5在所有受检脑区（含MAV）中均因AMPH与EIH暴露出现表达下调，且在MAV中的下调程度更为显著。Esam基因的表达在所有受检脑区中均随AMPH暴露上调，而Angpt2的表达变化仅见于纹状体与顶叶皮层。目前尚不清楚这些表达变化如何影响MAV、纹状体或顶叶皮层的紧密连接功能、血脑屏障完整性与稳态。总体实验设计：本研究通过比较MAV与两处脑区（纹状体、顶叶皮层）的基因表达模式，旨在筛选对MAV功能具有关键作用的基因，并明确这些基因的表达是否对苯丙胺神经毒性暴露具有敏感性。