Impact of Aging and a High-Fat Diet on Adipose-Tissue-Derived Extracellular Vesicle miRNA Profiles in Mice

Figures

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  Figure 1. Metabolic characteristics of young and middle-aged mice fed a normal chow diet (NCD) or a high-fat diet (HFD). In both young and middle-aged mice fed an HFD, body weight (A) and white adipose tissue (WAT) weight (B) were significantly increased compared to mice fed an NCD. However, there was no difference between young mice fed an NCD and middle-aged mice fed an HFD. Fasting plasma insulin levels (C) revealed the same pattern. Glucose tolerance (D) and insulin tolerance tests (E) showed that all mice had impaired glucose control compared to young mice fed an NCD. A comparison of the area under the curve (AUC) of the insulin tolerance test clearly showed differences among groups (F). In (D,E), statistical significances were calculated at each time point based on young mice fed an NCD. The corresponding group colors represent the statistical results of each group compared to young mice fed an NCD in blue: green for young mice fed an HFD, red for middle-aged mice fed an NCD, and purple for middle-aged mice fed an HFD. * indicates p < 0.05, # indicates p < 0.01, and ns indicates no significance. Data are presented as means ± SE.

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  Figure 2. Characteristics of adipose-tissue-derived extracellular vesicles (AT EVs). The protein expression of an extracellular vesicle marker, Flotillin-1, and an adipose tissue marker, FABP4, was measured from AT EVs using Western blotting (A). The size and concentration of AT EVs were evaluated using a nanoparticle tracking analysis system. The x-axis of the graph shows the size range of the particle (0 to 1200 nm),and the red bar marks 500 nm. Each color of the graph indicates each sample tested (n = 3/each group). D10, D50 and D90 values mean percent undersize (B). Data are shown as means ± SE.

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  Figure 3. Four different DE-miRNA analyses and volcano plots of DE-miRNAs of each analysis. Schematic diagram displays four different combinations for analysis; Analysis1: M (middle-aged mice) vs. Y (Young mice)/NCD; Analysis2: M vs. Y/HFD; Analysis3: HFD vs. NCD/Y and Analysis4: HFD vs. NCD/M (A). Volcano plots demonstrate the expression patterns of DE- miRNAs in each analysis; Analysis1 (B), Analysis2 (C), Analysis3 (D), and Analysis4 (E). Dots in red indicate miRNAs with adjusted p-values < 0.05.

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  Figure 4. The anticipated pathways of DE-miRNAs in middle-aged mice fed an HFD compared to young mice fed an HFD (Analysis2: M vs. Y/HFD). Networking analysis of DE-miRNAs of middle-aged mice fed an HFD compared to young mice fed an HFD estimated that IGF1R is inhibited.