Aging of myelinating glial cells predominantly affects lipid metabolism and immune response pathways

In order to uncover the biological processes affected in glial cells by aging, we analyzed microarray gene expression of the Schwann cell-rich mouse sciatic nerve at 17 time-points throughout life, from day of birth until senescence. In addition, we combined these data with the microarray gene expression data of myelin 56 day-old mouse mutants carrying deletions of either Pmp22, SCAP or Lpin1. Seven mice were dissected per developmental or aging time-point. Both sciatic nerves were isolated from each mouse and tissues were pooled per time-point to extract total RNA. For the mutants and their wild-type littermates, sciatic nerves were dissected from three mice per genotype. Tissues were not pooled, which generated triplicates per genotype. Total RNA was extracted, purified and quality-controlled. For each condition, 300 ng of total RNA was used to synthesize cRNA using the Illumina TotalPrep RNA amplification kit (Ambion). The cRNA was then quantified, quality controlled and hybridized to the MouseWG-6 v1 expression Beadchips (Illumina) according to the manufacturer's instructions.为揭示衰老对胶质细胞影响的生物学过程，我们分析了富含施万细胞（Schwann cell）的小鼠坐骨神经在终生17个时间点的基因芯片表达数据，采样覆盖从出生当日直至衰老阶段。此外，我们将该数据集与携带Pmp22、SCAP或Lpin1基因缺失的56日龄髓鞘相关小鼠突变体的基因芯片表达数据进行整合。每个发育或衰老时间点均解剖7只小鼠，每只小鼠分离双侧坐骨神经，按时间点合并组织以提取总RNA。对于突变体及其野生型同窝对照，每个基因型取3只小鼠的坐骨神经，不进行组织合并，因此每个基因型设置3次生物学重复。总RNA提取完成后，依次进行纯化与质量质控。每个实验条件均取300 ng总RNA，使用Illumina TotalPrep RNA扩增试剂盒（Ambion）合成互补RNA（cRNA）。随后对cRNA进行定量、质控，并按照制造商说明书将其与MouseWG-6 v1表达微珠芯片（Illumina）进行杂交。