Comprehensive gene expression analyses of the rat prefrontal cortex after oxysterol treatment
Comprehensive gene expression analyses of the rat prefrontal cortex after oxysterol treatment
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DOI：
10.1111/jnc.12142
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发表时间：
2013-02
影响因子：
4.7
通讯作者：
S. Loke;Kazuhiro Tanaka;W. Ong
中科院分区：
文献类型：
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作者：
S. Loke;Kazuhiro Tanaka;W. Ong
7β -羟基胆固醇（7β - HC）和7 -酮胆固醇（7 - KC）等氧甾醇与神经退行性疾病的病理生理有关。本研究旨在探讨氧化甾醇对大鼠前额叶皮质（PFC）基因表达的影响。将7β - HC、7 - KC或胆固醇注射到大鼠PFC，并在注射后24小时从该脑区提取RNA并进行分析。微阵列分析鉴定出1365个基因，其表达受到7β‐HC和7‐KC的影响。其中，下调基因多于上调基因。通路分析表明，下调基因参与碳水化合物代谢、细胞信号传导和核酸代谢；其中大部分编码G蛋白偶联受体（gpcr）。所选基因的表达通过实时定量PCR进行验证。Western blots证实在‐7β‐HC治疗后1天催产素受体（Oxtr）下调。免疫组织化学分析显示Oxtr在pfc神经元中有定位，电镜下发现Oxtr在轴突末端有免疫反应性。总之，这些发现为氧化甾醇发挥其病理生理作用的分子机制提供了见解，并表明增加的氧化甾醇可能通过抑制gpcr的转录来影响突触功能。
Oxysterols such as 7β‐hydroxycholesterol (7β‐HC) and 7‐ketocholesterol (7‐KC) have been linked to the pathophysiology of neurodegenerative diseases. This study was carried out to examine the effect of oxysterols on global gene expression in the rat prefrontal cortex (PFC). 7β‐HC, 7‐KC, or cholesterol was injected into the rat PFC and RNA was extracted from this brain region at 24‐h post‐injection and analyzed. Microarray analyses identified 1365 genes, whose expressions were affected by both 7β‐HC and 7‐KC. Among these, down‐regulated genes outnumbered up‐regulated genes. Pathway analysis showed that down‐regulated genes had roles in carbohydrate metabolism, cell signaling and nucleic acid metabolism; and the majority of these encode G‐protein coupled receptors (GPCRs). Expression of selected genes were validated by quantitative real‐time PCR. Western blots confirmed down‐regulation of oxytocin receptor (Oxtr) at 1 day post‐7β‐HC treatment. Immunohistochemical analysis showed localization of Oxtr in neurons of the PFC. Electron microscopy identified the presence of Oxtr‐immunoreactivity in axon terminals. Together, these findings provide insights into molecular mechanisms through which oxysterols could exert their pathophysiological effects, and suggest that increased oxysterols may affect synaptic function by transcriptional repression of GPCRs.