Fig 1.
10,12 CLA (1%) promotes body weight reduction and subcutaneous fat loss.
A. Body weight was measured weekly. B. Total body fat and lean mass were measured after 9 weeks (baseline) and 12+5 weeks of HFHS+test diets. Data are also presented as % body fat mass. C. Representative images of epididymal (EWAT) and inguinal (IWAT) fat pads at sacrifice. D. White adipose tissue (WAT) weights at sacrifice, expressed as percent total body weight. Data are presented as mean ± SEM, n = 10–15 mice/group. *P<0.05 from HFHS control; ^P<0.05 from 0.5% CLA; **P<0.05 from CR.
Fig 2.
Energy expenditure and respiratory quotient are increased by 10,12 CLA.
A. Food intake, B. ambulatory activity, C. heat production, and D. respiratory quotient were measured every 10 minutes for 3 days at baseline (B: 12 weeks on HFHS diet), and again 2- and 6-weeks after initiation of the indicated diets, and presented as the average values. Representations of continuous heat production (C) and respiratory quotient (D) measurements are indicated. Shaded areas indicate the dark cycle. Data are presented as mean ± SEM, n = 8-12/group. #P<0.05 from baseline, *P<0.05 from HFHS control, **P<0.05 from CR.
Fig 3.
10,12 CLA fails to improve glucose metabolism.
A. Fasting blood glucose taken at indicated time points. B. Fasting plasma insulin measured at sacrifice. C-D. Area under the curve (AUC, C) for glucose tolerance test (GTT, D) performed at 10 weeks (baseline) and 12+6 weeks on HFHS+indicated diets. E. Plasma insulin measured at the 30 minute time point during the GTT. F. Insulin tolerance test (ITT) performed at 11 weeks (baseline) and 12+7 weeks on the indicated diets. G-H. Fasting plasma leptin (G) and adiponectin (H) measured at baseline and sacrifice. Data are presented as mean ± SEM, n = 10-15/group. #P<0.05 from baseline, *P<0.05 from HFHS control, **P<0.05 from CR.
Fig 4.
10,12 CLA worsens hepatic triglyceride content.
A. Liver weight expressed as a percentage of total body weight. B-D. Liver triglycerides (TG, B), cholesterol (C) and glycogen (D) were measured, normalized to total protein or liver weight. E. Representative images of liver sections stained with hematoxylin and eosin, scale bar = 400 μm. Data are presented as mean ± SEM, n = 5-15/group. *P<0.05 from HFHS control, **P<0.05 from CR.
Table 1.
Liver gene expression.
Fig 5.
Differential expression of lipid metabolism genes in visceral and subcutaneous depots in response to 10,12 CLA and caloric restriction.
A. Expression of lipid catabolism genes (Cpt1b, Ppara, Ppard) and adipogenic genes (Pparg and Adipoq) from EWAT and IWAT (normalized to HFHS-fed EWAT). B. Representative Western blot for PPARγ, with tubulin used as a loading control. C. L-carnitine levels in EWAT and IWAT. D. Adipocyte size distribution of EWAT (left) and IWAT (right). Data are presented as mean ± SEM, n = 10-15/group. *P<0.05 from HFHS control, #P<0.05 from EWAT, **P<0.05 from CR.
Fig 6.
Inguinal white adipose tissue becomes enriched with alternatively activated macrophages following 10,12 CLA supplementation.
A. Expression of genes representative of macrophages (Mac2), chemotactic factors (Ccl2), inflammation (Tnf), alternatively activated macrophages (Arg1, Egr2), and pro-inflammatory macrophages (Nos2) from EWAT and IWAT (normalized to HFHS-fed EWAT). B. Representative images of Mac2 immunostaining from EWAT and IWAT, scale bar = 300 μm. Percent total Mac2 stained area for EWAT (left) and IWAT (right) shown below. Data are presented as mean ± SEM, n = 10-15/group. *P<0.05 from HFHS control, **P<0.05 from CR.
Fig 7.
10,12 CLA induces the browning of white adipose tissue.
A. Expression of genes associated with browning (Ucp1, Fndc5, Cidea, Adrb3) from EWAT, IWAT, and BAT (normalized to HFHS-fed EWAT). B. Representative images of UCP1 immunostaining from EWAT, IWAT, and BAT, scale bar = 300 μm. Percent total UCP1 stained area for EWAT (left), IWAT (middle), and BAT (right) shown below. Data are presented as mean ± SEM, n = 5-15/group. *P<0.05 from HFHS control, **P<0.05 from CR.
Fig 8.
Cold exposure potentiates 10,12 CLA-induced increases in energy expenditure.
A. After 12+9 weeks on HFHS+indicated diets, a separate group of mice were housed at 5°C for 6 hours and core body temperatures recorded every 10 minutes. B. The change from time = 0 was calculated after 10, 180, and 360 minutes of cold exposure. C-E. Heat production (C), locomotor activity (D) and respiratory quotient (RQ) (E) were measured continuously during an ambient room temperature exposure (22°C for 72 hours, after 8 weeks on test diets) followed by an acute cold exposure (5°C for 6 hours after 9 weeks on test diets). 22°C data in (C-E) are adjusted to reflect only values collected during equivalent time periods as the 5°C exposure. F-H. Food intake (F), heat production (G), and ambulatory activity (H) were measured during the same ambient room temperature exposure (22°C for 72 hours, after 8 weeks on test diets) and again during a chronic moderately cold exposure (14°C for 72 hours, after 10 weeks on test diets). Data are presented as mean ± SEM, n = 4/group. #P<0.05 from 22°C, *P<0.05 from HFHS control.