Insulin promotes LTP in mice by switching the energy substrate preference of astrocytes to fatty acids [Mus]

A total of 46,202 transcripts were detected from RNA extracts from Mus musculus hippocampus. Genes were filtered by setting the minimum FPKM value to log2, followed by a parametric statistical test to identify differentially expressed genes. Within 15 min of insulin administration, 181 transcripts were upregulated and 55 were downregulated. At this early time-point, genes with altered expression were almost exclusively related to neuronal functions. Within 1h following insulin treatment, a similar number of transcripts (173) were upregulated and the expression of three-fold more genes (140) were downregulated. At this time-point, 12 genes associated with the release of lipids and fatty acids were increased. Within 6h following intranasal insulin administration, the number of transcripts with elevated expression remained similar (164), but the number of genes with reduced expression declined to 77. At this time point the genes with elevated expression were largely relate to lipid metabolism. These data demonstrate that insulin delivered directly to the brain produces a rapid, robust, and time-dependent modification in gene expression related to lipid metabolism. Effect of Insulin exposure in the regulation of lipid metabolism in the brain

本研究从小鼠（Mus musculus）海马体的RNA提取物中共检测到46202个转录本。通过将最低FPKM值设为log2对基因进行筛选，随后采用参数统计检验方法鉴定差异表达基因。在胰岛素给药后15分钟内，共有181个转录本上调、55个转录本下调。该早期时间节点下，表达改变的基因几乎全部与神经元功能相关。在胰岛素处理后1小时，上调的转录本数量相仿（173个），而下调的基因数量则达140个，较15分钟时的下调基因数增加两倍有余（约为其时的三倍）。此时，共有12个与脂质及脂肪酸释放相关的基因表达上调。在鼻内给予胰岛素后6小时内，表达上调的转录本数量仍相近（164个），但表达下调的基因数量则降至77个。该时间节点下，表达上调的基因主要与脂质代谢相关。上述数据表明，直接向脑部递送胰岛素可快速、强效且呈时间依赖性地改变与脂质代谢相关的基因表达。
胰岛素暴露对脑部脂质代谢调控的影响