Role of thyroid hormone homeostasis in obesity-prone and obesity-resistant mice fed a high-fat diet  Shu-Fang Xia, Xiao-Mei Duan, Li-Yue Hao, Li-Ting Li, Xiang-Rong Cheng, Zhen-Xing Xie, Yi Qiao, Li-Rong Li, Xue Tang, Yong-Hui Shi, Guo-Wei Le  Metabolism - Clinical and Experimental  Volume 64, Issue 5, Pages 566-579 (May 2015) DOI: 10.1016/j.metabol.2014.12.010 Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 1 Phenotypes of OP and OR mice fed an HFD. (A) Body weight profiles. Mice were weighed weekly for the 27weeks duration of the study. (B) Cumulative body weight gain. (C) Cumulative food intake (n=35). (D) Cumulative energy intake. (E) Retroperitoneal fat pad mass index (n=8), (F) epididymal fat pad mass index (n=8) and (G) liver mass index (n=8) in LFD, OP and OR mice in the 7th week and 27th week. Samples for body weight and food intake were 70 in the first 7weeks and 35 in the subsequent 20weeks. Data were presented as mean±SEM. LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD; #P<0.05 vs. OP. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 2 Indirect calorimetry in LFD, OP and OR mice in the 7th week and 27th week. (A–D) RER, (E–H) energy expenditure, and (I–L) ambulatory activities. Bar graphs represent mean values during the light and dark cycles. Data were expressed as mean±SEM (n=8). LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD mice; #P<0.05 vs. OP mice. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 2 Indirect calorimetry in LFD, OP and OR mice in the 7th week and 27th week. (A–D) RER, (E–H) energy expenditure, and (I–L) ambulatory activities. Bar graphs represent mean values during the light and dark cycles. Data were expressed as mean±SEM (n=8). LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD mice; #P<0.05 vs. OP mice. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 3 Differences of circulating thyroid hormones, hepatic D1 among LFD, OP and OR mice. Determination of serum T4 (A), T3 (B), hepatic D1 activity (C) and Dio1 relative mRNA expression (D) in normal mice fed an LFD as well as OP and OR mice fed an HFD in the 7th week and 27th week. Data were expressed as mean±SEM (n=8). LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD mice; #P<0.05 vs. OP mice. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 4 Differences of HPT axis function among LFD, OP and OR mice. Determination of serum TSH (A) (n=8); hypothalamic Trh mRNA expression (B) (n=5), D2 activity (C) (n=5) and Dio2 mRNA expression (D) (n=5); pituitary D2 activity (E) (n=5) and Dio2 mRNA expression (F) (n=5), Tsh mRNA expression (G) (n=5); thyroid hormone synthesis related genes (Tshr, Nis, Tpo, Tg) mRNA expression (H and I) (n=8) in normal mice fed an LFD as well as OP and OR mice fed an HFD in the 7th week and 27th week when the mice were sacrificed. Data were expressed as mean±SEM. LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD mice; #P<0.05 vs. OP mice. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions

Fig. 5 Differences of hepatic lipid profiles, histology and thyroid hormone responsive genes expressions among LFD, OP and OR mice. Changes in hepatic TG (A), TC (B) and FFAs (C) in normal mice fed an LFD as well as OP and OR mice fed an HFD in the 7th week and 27th week. (D) Oil-red O stains of paraformaldehyde-fixed liver sections prepared from LFD mice that were fed low-fat diet and OP and OR mice that were fed high-fat diet for 7weeks and 27weeks (bars: 100μm). q-PCR assays of liver RNAs revealed alterations of thyroid hormone target genes expression of mice when they were fed experimental diets for 7weeks (E) and 27weeks (F), respectively (n=8). Data were expressed as mean±SEM. TG, triglycerides; TC, total cholesterol; FFAs, free fatty acids; LFD, low-fat diet; OP, obesity-prone; OR, obesity-resistant. *P<0.05 vs. LFD mice; #P<0.05 vs. OP mice. Metabolism - Clinical and Experimental 2015 64, 566-579DOI: (10.1016/j.metabol.2014.12.010) Copyright © 2015 Elsevier Inc. Terms and Conditions