C57bl 6j control mice

All animal procedures were approved by the University of California Berkeley Animal Care and Use Committee. Cd36^−/− mice on a C57BL/6J background were kindly provided by Dr. Maria Febbraio (Febbraio et al., 1999 (link)). Control C57BL/6J mice (referred to as WT in this paper) were purchased from the Jackson Laboratory. All animal experiments were conducted in 8–20 week-old male mice housed under standard conditions. They were given free access to water and rodent chow (Harlan Teklad #2018). For cold exposure studies, singly caged mice were housed at 4°C for 5 h. Core body temperature was measured rectally using a lubricated thermistor probe (Yellow Springs Instruments) at 30 min intervals. Shivering was determined by attaching a wireless accelerometer (weight=1.5g) to the mouse back and quantified with millisecond resolution in three dimensions for 2 h. For serum analysis, retro-orbital blood was collected from anesthetized mice prior to and following 2.5 and 5 h cold exposure. Serum samples were analyzed for non-esterified fatty acids and glucose using colorimetric kits according to the manufacturer’s protocol (Wako Chemicals).

All animals were housed at constant temperature (20°C–23°C) in 12-hour light/dark cycles with free access to water and standard chow ad libitum (Harlan Teklad Global Diet, catalog 2018, for BALB/cJ mice and FormuLab diet, catalog 5008, from LabDiet for C57BL/6J mice). To induce obesity in C57BL/6J mice, their diet was switched to Harlan Teklad custom high-fat diet (45% calories from fat), catalog TD06415. BALB/cJ Sdc1^−/− mice have been described previously (4 (link), 44 (link)); at the time of study, the control BALB/cJ mice and Sdc1^−/− BALB/cJ mice were age-matched and 8–10 weeks old. C57BL/6J ob/ob mice and C57BL/6J control mice were distributed by the Jackson Laboratory, bred in-house, and imaged when they were 7–11 weeks old. Data shown is from female mice, except for data panels that describe the results of high-fat diet administration, as high-fat diets were administered to male mice.

Inbred BALB/c mice and outbred Swiss Webster mice at 6~8 weeks of age were purchased from Charles River Laboratories. Mice of both genders were used randomly with no notable difference. Eighteen-month-old BALB/c mice (old mice) were purchased from National Institute of Aging (NIA). Irf7−/− mice on C57BL/6J background were a kindly gift of Dr T. Taniguchi, Tokyo University ^{43 (link)} and C57BL/6J control mice were obtained from Jackson Laboratories. MHC II-EGFP mice expressing MHC class II molecule infused into enhanced green fluorescent protein (GFP) were a kindly gift of Drs. Boes and Ploegh, Harvard Medical School ^{23 (link)}. Male Yorkshire pigs at 4 months of age were obtained from the Teaching and Research Resources at Tufts University. The animals were housed in the specific pathogen free animal facilities of Massachusetts General Hospital (MGH) in compliance with institutional, hospital, and NIH guidelines. All studies were reviewed and approved by the MGH Institutional Animal Care and Use Committee.

Male db/db homozygous mice on the C57Bl6/J background and wildtype C57Bl6/J control mice were obtained from Jackson Laboratories (Bar Harbor, Maine, USA) at five weeks of age. Mice were routinely housed four per cage, with the exception that mice used for assessment of food intake and glucose and insulin metabolism were singly housed. After one week of acclimation to the animal facility, mice were injected with metyrapone (Tocris Bioscience; 100mg/kg, IP) every day between 8 and 10AM (lights-on at 7AM) to lower and normalize corticosterone levels. This dose was selected on the basis of previous studies using metyrapone to lower corticosterone levels in db/db mice (Takeshita et al., 2000 (link)). After fourteen days of treatment with metyrapone or vehicle, (n=8) mice from each genotype and drug condition were prepared for various endpoints as shown in Figure 1A.