Molecular markers of chronic stress vulnerability/resilience

描述（由申请人提供）：压力在大脑和外周系统中启动一系列生化事件，使生物体能够应对新的和具有挑战性的情况。然而，慢性应激状态的累积效应对大多数生理系统产生负面影响，因为靶细胞长时间暴露于应激介质中。人类的研究发现，指出慢性压力与焦虑症、抑郁症和认知障碍之间存在联系，这些发现已被啮齿类动物的行为观察广泛支持。慢性或长期压力的生理和行为后果取决于个体脆弱性的遗传和环境介质。尽管对压力进行了大量的研究，但脆弱或恢复的分子机制尚不清楚。本提案旨在确定对慢性应激的敏感性和恢复力的分子标记，作为鉴定应激介质的第一步。本研究的目的是：1)在四种不同的近交系大鼠中，确定慢性抑制应激（CRS）范式停止期间和之后，慢性抑制应激的行为后果。选择这些自交系，Wistar Kyoto (WKY), Fisher 344 (F344), Brown Norway （BN）和Lewis (LEW)，是因为它们对慢性应激具有独特的易感性和/或恢复力。采用升高+迷宫（EPM）测试评估慢性应激对焦虑相关行为反应的影响。2)采用假设生成、无偏置的方法——affmetrix DMA微阵列分析，我们将检测四种自交雄性动物的杏仁核和海马两个脑区以及血液中基因表达谱的变化对CRS的响应。将对暴露于以下环境的动物组织进行微阵列分析：1)无应激，这将用于确定基线基因表达。14天的CRS范式，这将告诉我们应激反应的分子标记，以及iii)。停用CRS后10天测定应激后反应标志物。通过对从与焦虑和压力高度相关的两个大脑区域和血液中分离的RNA进行微阵列分析，我们将确定慢性应激源暴露期间和之后这些组织中基因表达的共同特征。具体目标3。通过实时定量RT-PCR确定最有希望的候选标记基因。这项探索性研究将确定在慢性应激反应中特定脑区或血液中单独或同时发生改变的基因。这些情况将使我们能够从血液中确定慢性压力的候选标记物，这些标记物代表了人类遗传物质的可获取来源。

DESCRIPTION (provided by applicant): Stress initiates a cascade of biochemical events in the brain and peripheral systems that enable the organism to cope with novel and challenging situations. However, the cumulative effects of chronic stress states negatively affects most physiologic systems because the target cells are exposed to the stress mediators over a long period of time. Human findings, pointing to a linkage between chronic stress and anxiety disorders, depression and cognitive impairments, have been extensively supported by behavioral observations in rodents. The physiological and behavioral consequences of chronic or prolonged stress depend on genetic and environmental mediators of the individual's vulnerability. The molecular mechanisms of vulnerability or resilience are not known despite the large number of studies investigating stress. This proposal aims to determine the molecular markers of sensitivity and resilience to chronic stress as a first step towards the identification of stress mediators. The aims of this proposal are: Specific Aim 1) Determine the behavioral consequences of chronic restraint stress, during and after the cessation of a chronic restrain stress (CRS) paradigm in four different inbred strains of rats. These inbred strains, the Wistar Kyoto (WKY), Fisher 344 (F344), Brown Norway (BN) and Lewis (LEW), are chosen to represent distinctive susceptibility and/or resilience to chronic stress. The elevated plus-maze (EPM) test will be employed to assess the effect of chronic stress on anxiety-related behavioral responses. Specific Aim 2) Using a hypothesis-generating, unbiased approach, the Affimetrix DMA microarray analysis, we will examine the gene expression profile changes in two brain areas, the amygdale and the hippocampus, and blood of male animals from the four inbred strains in response to CRS. Microarray analysis will be carried out on tissues obtained from animals exposed to: i) No stress, which will serve to determine the baseline gene expression ii.) 14 days of the CRS paradigm, which will inform us on the molecular markers of stress responsivity, and iii.) 10 days after the cessation of CRS to determine markers of post-stress responsivity. By employing microarray analyses of RNA isolated form two brain regions highly relevant to anxiety and stress and from blood, we will determine the common profiles of gene expression in these tissues during and after chronic stressor exposure. Specific Aim 3. Confirm the most promising candidate marker genes by quantitative real-time RT-PCR. This exploratory study will identify genes that are altered solely or concomitantly in specific brain regions or blood in response to chronic stress. These scenarios would allow us to identify candidate markers of chronic stress from the blood representing an accessible source of genetic material in humans.