Depot-specific adaption of adipose tissue for different exercise approaches in high-fat diet/streptozocin-induced diabetic mice

FIGURE 1. Experimental design diagram. In phase 2, the HFD/STZ mice were kept on a high-fat diet, and the control mice were kept on a normal diet.

FIGURE 2. The effects of exercise training on the body composition (A) Weight change during 12 weeks of dietary intervention. (B) Fasting blood glucose was measured 1 week after 12 weeks of high-fat diet intervention followed by intraperitoneal injection of STZ. (C–E) Body composition of mice in control and HFD/STZ groups after exercise intervention. n = 9. All data are presented as mean ± SD. vs. control group: #p < 0.05, ##p < 0.01, ###p < 0.001; vs. sedentary group: **p < 0.01, ***p < 0.001; vs. HIIT group: &p < 0.05, &&p < 0.01, &&&p < 0.001.

FIGURE 3. The effects of exercise training on adipose tissue morphology and inflammatory factors (A) H&E staining of iBAT, sWAT, and eWAT from control and HFD/STZ mice (magnification: ×200, scale bar:50 μm). Quantification of lipid droplet size in iBAT (B) and adipocyte size in sWAT (C) and eWAT (D). Data were collected from H&E-stained sections of 3 individual mice in each group, 6 fields per mouse, measured by ImageJ software. (E) MCP1 and IL-1β gene expression in iBAT, sWAT and eWAT of control mice and HFD/STZ mice (n = 6 for each group). All data are presented as mean ± SD. vs. control group: # p < 0.05, ### p < 0.001; vs. sedentary group: **p < 0.01, ***p < 0.001; vs. aerobic group: @p < 0.05, @@p < 0.01; vs. HIIT group: &p < 0.05, &&p < 0.01.

FIGURE 4. The effects of exercise training on the expression of mitochondrial-related genes. PGC1α (A), COX4 (B) and COX8B (C) gene expression in iBAT, sWAT and eWAT of control mice and T2DM mice (n = 6 for each group). Values are mean ± SD and the expression of genes is corrected for the housekeeping gene β-actin. vs. control group: ## p < 0.01, ### p < 0.001; vs. sedentary group: *p < 0.05, **p < 0.01, ***p < 0.001; vs. resistance group: $$p < 0.01; vs. aerobic group: @p < 0.05, @@p < 0.01; vs. HIIT group: &p < 0.05, &&p < 0.01, &&&p < 0.001.

FIGURE 5. The effects of exercise training on UCP1 and TMEM26 mRNA level. UCP1 (A) and TEM2M26 (B) gene expression in iBAT, sWAT and eWAT of control mice and HFD/STZ mice (n = 6 for each group). Values are mean ± SD and the expression of genes is corrected for the housekeeping gene β-actin. vs. control group: # p < 0.05, ## p < 0.01, ### p < 0.001; vs. sedentary group: *p < 0.05, **p < 0.01, ***p < 0.001; vs. HIIT group: &p < 0.05, &&p < 0.01.

FIGURE 6. The effects of exercise training on UCP1 protein levels. (A) UCP1 immunofluorescence staining of iBAT, sWAT and eWAT from control and HFD/STZ mice (magnification: ×200, scale bar:50 μm). Western blot analysis and quantification for UCP1 using the total protein isolated from iBAT (B), sWAT (C) and eWAT (D) for control and HFD/STZ mice. The protein content is expressed fold change to the control. All data are normalized to HSP90 and are expressed as mean ± SD (n = 6 for each group). vs. sedentary group: *p < 0.05, **p < 0.01.

FIGURE 7. The effects of exercise training in TH-positive sympathetic nervous terminals. (A) TH immunofluorescence staining of iBAT, sWAT and eWAT from control and HFD/STZ mice, white arrows indicate TH-positive fibers (magnification: ×400, scale bar:50 μm). Western blot analysis and quantification for TH using the total protein isolated from iBAT (B), sWAT (C) and eWAT (D) for control and HFD/STZ mice. The protein content is expressed relative to the control. All data are normalized to HSP90 and are expressed as mean ± SD (n = 6 for each group). *p < 0.05 vs. sedentary group.