Chronic CeA CRF overexpression on gene expression in PVN CRF-expressing cells

项目简介：许多重性抑郁症（MOD）患者的下丘脑垂体肾上腺（HPA）轴过度活跃。这种功能障碍在治疗成功后恢复正常，可能是治疗背后的共性。新的治疗方法应该针对HPA轴过度活跃的来源：可能是来自室旁下丘脑（PVN）的促肾上腺皮质激素释放因子（CRF）失调。PVN的活性受许多边缘结构的协调调节，其中一个或多个边缘结构的可塑性可能导致PVN CRF输出增强和随后的HPA轴功能障碍。一个可能的罪魁祸首是中央杏仁核（CeA），这是另一个表达高浓度CRF的区域，被认为是介导应激诱导行为的。本研究的目的是确定(1)除了行为影响外，CeA慢性增加的CRF驱动是否会重现与抑郁症状相关的内分泌变化；(2)CeA中慢性过度表达CRF是否会导致PVN CRF神经元的基因表达变化，并与所观察到的内分泌和行为中断相关。慢病毒载体将在成年动物CeA中表达CRF的神经元（LVCRFp3.OCRF）中过表达CRF。通过创建转基因小鼠，使表达CRF的细胞也表达绿色荧光蛋白（GFP），可以很容易地识别表达CRF的细胞。这些细胞可以通过荧光活化细胞分选分离出来，并进行基因表达分析，以比较基础条件下或CeA中长期过表达CRF后PVN和CeA中CRF和非CRF表达的细胞。预计慢性CeA CRF过表达将导致HPA轴过度活跃，这至少可以部分解释PVN CRF细胞的基因表达变化。与公共卫生相关：慢性CRF升高可能引发一系列改变基因表达和内分泌信号的事件，最终导致抑郁症状。CRF由许多脑结构释放，但这些区域中CRF之间的关系尚不完全清楚，因为以前的技术无法模拟慢性CRF升高。利用先进的技术，将一个区域的CRF过表达，然后将另一个区域的CRF细胞分离出来，以确定可能与观察到的内分泌和行为改变相关的基因表达变化。

DESCRIPTION (provided by applicant): Project Summary: The hypothalamic pituitary adrenal (HPA) axis is hyperactive in many patients with major depressive disorder (MOD). This dysfunction normalizes with successful treatment and may be a commonality behind treatments. Novel treatments should target the source of HPA axis hyperactivity: presumably dysregulated corticotropin releasing factor (CRF) from the paraventricular hypothalamus (PVN). PVN activity is regulated by the coordination of numerous limbic structures and plasticity in one or more of these regions may cause enhanced PVN CRF output and subsequent HPA axis dysfunction. One likely culprit is the central amygdala (CeA), another region expressing high concentrations of CRF and thought to mediate stress- induced behavior. The Aims of the present research are to determine (1) if, in addition to behavioral effects, chronic increased CRF drive from the CeA reproduces endocrine changes associated with depressive symptoms and (2) if chronically overexpressing CRF in the CeA results in gene expression changes in PVN CRF neurons that correlate with the observed endocrine and behavioral disruptions. A lentiviral vector will overexpress CRF in CRF-expressing neurons (LVCRFp3.OCRF) in the CeA of adult animals. CRF-expressing cells will be easily identifiable by creating a transgenic mouse in which CRF- expressing cells also express green fluorescent protein (GFP). These cells can be isolated via fluorescence activated cell sorting and subjected to gene expression analysis to compare the CRF and non CRF- expressing cells in the PVN and CeA under basal conditions or after chronically overexpressing CRF in the CeA. It is expected that chronic CeA CRF overexpression will result in HPA axis hyperactivity that can be explained at least partially by gene expression changes in PVN CRF cells. Relevance to Public Health: Chronic elevations in CRF may initiate a chain of events altering gene expression and endocrine signaling and eventually leading to symptoms of depression. CRF is released by numerous brain structures but the relationship between CRF in these regions is incompletely understood because previous technology has been unable to mimic chronic CRF elevations. Using superior techniques, CRF will be overexpressed in one region and then CRF cells in another region will be isolated to identify gene-expression changes that may correlate with observed endocrine and behavioral alterations.