Body weight and food intake measurements

Body weight measurements for WT and N221D PC1/3 males and females were started at the age of ∼4 weeks. At age 12 weeks, mice were first acclimated to single housing with normal chow. At age 13 weeks, mice were weighed (to ensure that their body weights were stable from the prior week), then transferred to a fresh cage and provided with a preweighed amount of food (20 pellets, or ∼80 to 100 g per mouse). After 1 week, at age 14 weeks, the mice were weighed and the remaining food was measured to calculate the daily food intake. Mice were then given ad libitum food. At age 15 weeks, the body composition was measured by nuclear magnetic resonance (NMR), and a fasting-refeeding experiment was performed starting at 4:00 pm. Daily food intake was measured, and mice were weighed. After 48 hours, mice were subjected to 18-hour fasting. Following this fast, mice were weighed, provided with three pellets of food, and food intake was measured at 1, 2, 4, and 24 hours. Mice were weighed after refeeding, and then again provided with ad libitum food during the weekend. At age 16 weeks, an oral glucose tolerance test (GTT) was performed after a 5-hour fast. Two days later, mice were killed by decapitation under isoflurane anesthesia and whole-trunk blood was collected (36). All dissections were performed at midday.