Figure 1
From: mTORC1 is Required for Brown Adipose Tissue Recruitment and Metabolic Adaptation to Cold
Cold exposure promotes mTORC1 activity in BAT through the sympathetic nervous system.
Mice were either kept at thermoneutrality (warm; 30 °C) or exposed to cold (10 °C) during 2 weeks. Acute cold exposure (6-hour at 10 °C) was performed following 2 weeks at thermoneutrality. (A) Gene expression of Pgc1a and Ucp1 in BAT (n = 8 for warm; n = 5 for acute cold; n = 8 for chronic cold; mean +/− SEM; ANOVA; *P < 0.05; ***P < 0.001). (B) (Left) Representative pictures of BAT collected from mice kept at thermoneutrality or exposed to cold for 2 weeks. (Right) BAT weight measured from the same animals (n = 14–22; mean +/− SEM; t-test; ***P < 0.001). (C) Representative H&E staining of representative BAT collected from mice kept at thermoneutrality or in cold for 2 weeks. (D) (Left) Total DNA content (n = 7–8; mean +/− SEM; t-test; *P < 0.05) and (right) mtDNA content measured in mice kept in warm or cold for 2 weeks. (n = 8; mean +/− SEM; t-test; ***P < 0.05). (E) Western blots performed on BAT collected from mice following warm or acute cold exposure. Mice were fasted during the cold exposure (6-hour period). (F) Western blots performed on BAT collected from mice following warm or acute cold exposure. A group of cold-exposed mice received an acute intraperitoneal injection of rapamycin (2 mg/kg) one-hour prior to the cold exposure (6-hour period). (G) Western blots performed on BAT collected from mice following warm or chronic cold exposure. Mice were fasted during the last 6 hours. (H) Representative pictures of unilateral BAT denervation. (Left) Sham mice kept at thermoneutrality, (middle) unilateral BAT denervation following acute cold or (right) chronic cold exposure. (I) BAT lobe weight following unilateral BAT denervation (n = 8 for Sham-Warm; n = 5 for acute cold; n = 10 for chronic cold; mean +/− SEM; Two-way ANOVA; ***P < 0.001 vs. Sham-Warm lobe; ###P < 0.001 vs. Innervated lobe). (J) Western blots performed on BAT collected from mice with unilateral BAT denervation. Mice were fasted during the last 6 hours. Each mouse was its own control. In this panel, (I) refers to the innervated lobe and and (D) refers to the denervated lobe. All gels have been run under the same experimental conditions.
