Fig. 4.

Mice with mutation in eIF2α (Eif2a^S/A) display increased body weight compared with wild-type Eif2a^S/S mice without differences in adipocyte size or serum lipid levels. (a–f) Weight gain, body fat mass, body lean mass, fluid mass, blood glucose and insulin levels. Mice were fed an HFD for 13 weeks and metabolic variables were measured using an NMR-based analyser. Eif2a^S/A (n=12) and Eif2a^S/S (n=7). (g, h) No difference in adipocyte size between genotypes. After HFD for 13 weeks, epididymal fat tissues were obtained for histochemistry and representative images of epididymal fat pads are shown in (g). Scale bar indicates 100 μm. (h) Histogram shows the distribution of adipocyte size. The x-axis represents the logarithm of cell size in pixels, while the y-axis shows the percentage of cells having a given size for each group of mice. White bars, Eif2a^S/S; grey bars, Eif2a^S/A. (i) The number of cells from the SVF of adipose tissues from Eif2a^S/A (n=4) and Eif2a^S/S (n=4) mice at age of 6–8 weeks on a regular diet. (j) Proliferation rate of cells from SVF. Cells from SVF were plated in replicate and the number of cells was counted after 4 days of culture using an automated cell counter. Each suspension was counted twice. The y-axis represents the percentage of the initial cell number. Plasma levels of non-esterified NEFA (k), cholesterol (l) and triacylglycerol (m) after 13 weeks of HFD. Sera from Eif2a^S/A (n=11) and Eif2a^S/S (n=9) mice were collected and measured for NEFA and cholesterol as indicated in methods. (n) Hepatic triacylglycerol levels. Liver samples were collected for analysis after 13 weeks of HFD. (o) Insulin tolerance tests (ITTs). After 13 weeks of HFD, blood glucose levels were measured at the indicated times after insulin injection (0.75 U/kg body weight). Eif2a^S/A (n=12, squares) and Eif2a^S/S (n=9, circles). *p <0.05. BW, body weight