Laboratory of Molecular Genetics, Rockefeller University, New York, NY 10065, USA.
Cell Metab. 2013 Oct 1;18(4):596-607. doi: 10.1016/j.cmet.2013.09.002.
Comprehensive transcriptional profiling of glucose-sensing neurons is challenging because of low expression levels of glucokinase (Gck) and other key proteins that transduce a glucose signal. To overcome this, we generated and validated transgenic mice with a neuronal/endocrine-specific Gck promoter driving cre expression and mated them to mice with cre-dependent expression of an EGFP-tagged ribosomal protein construct (EEF1A1-LSL.EGFPL10) that can be used to map and profile cells. We found significant Gck expression in hypothalamic and limbic regions in cells that are activated following administration of glucose or 2-deoxyglucose. Transcriptional profiling from Gck-cre/EEF1A1-LSL.EGFPL10 mice enriched known and previously unknown glucose-sensing populations including neurons expressing growth hormone releasing hormone (GHRH). Electrophysiological recordings show that hypoglycemia activates GHRH neurons, suggesting a mechanistic link between hypoglycemia and growth hormone release. These studies provide a means for mapping glucose-sensitive neurons and for generating transcriptional profiles from other cell types expressing cre in a cell-specific manner.
全面的葡萄糖感应神经元转录谱分析具有挑战性，因为葡萄糖激酶 (Gck) 和其他转导葡萄糖信号的关键蛋白的表达水平较低。为了克服这一困难，我们生成并验证了具有神经元/内分泌特异性 Gck 启动子驱动 cre 表达的转基因小鼠，并将其与具有 cre 依赖性表达 EGFP 标记核糖体蛋白构建体 (EEF1A1-LSL.EGFPL10) 的小鼠交配，该构建体可用于对细胞进行定位和分析。我们发现，在给予葡萄糖或 2-脱氧葡萄糖后被激活的下丘脑和边缘区域的细胞中，Gck 的表达显著。来自 Gck-cre/EEF1A1-LSL.EGFPL10 小鼠的转录谱分析富集了已知和以前未知的葡萄糖感应群体，包括表达生长激素释放激素 (GHRH) 的神经元。电生理记录显示，低血糖激活 GHRH 神经元，提示低血糖和生长激素释放之间存在机制联系。这些研究为绘制葡萄糖敏感神经元图谱以及以细胞特异性方式从其他表达 cre 的细胞类型生成转录谱提供了一种手段。
