Human Post-Mortem Pathology (in-situ Hyb etc.)

人类死后病理学（原位杂交等）

• 批准号: 7167302
• 负责人: GRAZYNA RAJKOWSKA
• 金额: $ 22.72万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7167302
• 关键词: age difference; aging; cell morphology; cell sorting; human tissue; immunocytochemistry; in situ hybridization; innervation; interneurons; major depression; messenger RNA; microglia; neurons; pathologic process; postmortem; prefrontal lobe /cortex; protein localization; receptor expression; serotonin; serotonin receptor

Major depressive disorder (MDD) is characterized by reductions in the density and size of neuronal and glial cells in prefrontal cortex. We find these cellular changes to be age-dependent as younger depressed show prominent reductions in the density of glial cells (astrocytes), whereas older depressed have marked reductions in the density of pyramidal (presumably glutamate) neurons and calbindin-immunoreactive interneurons (mostly co-localizing GABA). Since, astrocytes regulate concentration of glutamate, an excess of which is neurotoxic, we propose that an early deficit in astrocytes in MDD could lead to an increase in the extracellular concentration of glutamate and to a reduction in pyramidal and GABA neurons later in life. Hence, there may be imbalances in GABA/glutamate homeostasis that are consistent with neuroimaging studies revealing changes in levels of GABA and glutamate in MDD which are reversible with antidepressant (SSRI) treatment. Cortical neurons are regulated in complex ways by serotonin acting (at least) at serotonin- 1A and -2A receptors located on these neurons and astrocytes. Pathology in ascending serotoninergic axons and postsynaptic receptors may be related to the activity, number and size of glutamate and/or GABA neurons and astrocytes in MDD. To date, there have been no studies on the expression or localization of serotonin receptors on specific cortical cell types in depression. The overall hypothesis is that in depression there will be age-dependent reductions in the density of astrocytes, glutamate pyramidal neurons and GABA interneurons, and that the expression of regulatory serotonin-1A and -2A receptors on these cells will be altered. These cell reductions will also be correlated with an age-related loss of serotonin innervation in prefrontal layers. To test these hypotheses, we will directly identify and quantify the packing density of astrocytes and glutamate and GABA neurons expressing mRNA for specific proteins (Aim 1). Moreover, we will assess the integrity of the serotonin system regulators (postsynaptic receptors and presynaptic axons) of prefrontal cells by estimating the proportion of cell types expressing mRNA for serotonin-1 A and -2A receptors (Aim 2), and the density of serotonin axons expressing the serotonin transporter (Aim 3). Double in situ hybridization, immunohistochemistry and 3-D cell counting techniques will be used in the same postmortem tissue sampled from the prefrontal cortex of younger and older subjects with MDD and non-depressed controls as used in our cell counting studies. This project will identify the cellular substrates of glutamate, GABA and serotonin interactions in the cortex and their potential role in the etiology, pathophysiology and age-related progression of depression. It may also reveal novel targets for preventing depressive illness and better antidepressant drug treatment.

重度抑郁症（MDD）的特征是神经元和神经胶质细胞的密度和大小减少， 前额叶皮层的细胞我们发现这些细胞变化是年龄依赖性的， 神经胶质细胞（星形胶质细胞）密度显著降低，而老年抑郁症患者的神经胶质细胞（星形胶质细胞）密度显著降低。 锥体（推测是谷氨酸）神经元和钙结合蛋白免疫反应性神经元的密度减少 中间神经元（主要是共定位GABA）。因为星形胶质细胞调节谷氨酸的浓度， 其中之一是神经毒性的，我们认为MDD中星形胶质细胞的早期缺陷可能导致 细胞外浓度的谷氨酸和减少锥体和GABA神经元以后的生活。 因此，可能存在GABA/谷氨酸稳态失衡，这与神经影像学一致。 研究揭示了MDD中GABA和谷氨酸水平的变化，这是抗抑郁药可逆的 （SSRI）治疗。皮质神经元以复杂的方式受到血清素的调节（至少）作用于血清素- 1A和-2A受体位于这些神经元和星形胶质细胞上。上行性肾上腺素能神经病理学 轴突和突触后受体可能与谷氨酸和/或GABA的活性、数量和大小有关 神经元和星形胶质细胞。到目前为止，还没有关于 抑郁症中特定皮质细胞类型的5-羟色胺受体。 总的假设是，在抑郁症中， 星形胶质细胞、谷氨酸锥体神经元和GABA中间神经元的表达， 这些细胞上的5-羟色胺-1A和-2A受体将被改变。这些细胞减少也将与 与年龄有关的前额叶5-羟色胺神经支配的丧失。为了验证这些假设，我们将 直接识别和量化星形胶质细胞和表达谷氨酸和GABA神经元的堆积密度， 特异性蛋白质的mRNA（Aim 1）。此外，我们将评估血清素系统调节剂的完整性， （突触后受体和突触前轴突）的前额叶细胞的细胞类型的比例估计 表达5-羟色胺-1A和-2A受体的mRNA（Aim 2），以及5-羟色胺轴突的密度 表达5-羟色胺转运体（Aim 3）。双原位杂交、免疫组化和三维 细胞计数技术将用于从前额叶皮层取样的相同死后组织中， 在我们的细胞计数研究中使用的年轻和老年MDD受试者和非抑郁对照。 这个项目将确定谷氨酸，GABA和血清素相互作用的细胞底物， 皮质及其在抑郁症的病因学、病理生理学和年龄相关进展中的潜在作用。它 也可能揭示预防抑郁症和更好的抗抑郁药物治疗的新靶点。