Effect of fasting and ketogenic diet on hippocampal astrocytes in vivo

To understand the transcriptional effect of fasting and feeding a ketogenic diet on mouse CNS astrocytes, we performed translating ribosomal affinity purification (TRAP) of mRNAs immunoprecipitated from hippocampus. TRAP mice express a ribosomal epitope tag upon Cre-induced recombination that can be immunoprecipitated following activation. We measured the abundance of actively translating mRNAs from a ribosomal pull-down that came from adult astrocyte (Aldh1l1-Cre)-specific TRAP mice that were subjected to one of three dietary conditions: four weeks of normal chow diet, four weeks of ketogenic diet (high-fat, low-carbohydrate)43, or an 18-hour fast. Immediately following the respective diets, forebrain and hippocampus was harvested from all groups, ribosomes were immunoprecipitated, and actively translating mRNAs in the ribosomes were purified. 11 total samples were analyzed. 4 Fed, 3 Fasted, and 4 Ketogenic diet fed mice.