Figure 2
IL-25 promotes fat mobilization and reduces lipid accumulation via the alteration of lipid metabolic enzymes in vivo. Mice were fed with HFD or NCD for 3 months, re-grouped and then injected with BSA or IL-25 (1 μg in 100 μl PBS for each mouse) every day for 7 days and then every other day for 16 days at the end of the HFD program. Real-time qPCR was applied to examine the gene expression of lipogenic enzymes, lipolytic enzymes and fatty-acid oxidation proteins in the eWAT or liver. The fold changes were relative to the BSA-treated group after normalization using the 18S rRNA. The data are presented as the mean±s.d. n=5; *P<0.05 versus the NCD group, #P<0.05 versus the HFD group. (a) The level of TG, FFA, HDL and LDL/VLDL in the serum. (b, c) The expression of ATGL in the eWAT (b) and liver (c). Gray scan histograms are presented as the mean±s.d. n=5; *P<0.05 versus the NCD group, #P<0.05 versus the HFD group. (d, g) hematoxylin and eosin staining of the eWAT and liver, and the histogram of adipocyte size and steatosis grade. Adipocyte size was analyzed using the ImageJ software. Two to three images and 15–20 adipocytes per image were applied for the measurement. Slides were photographed at × 40 magnification. (e, h) The level of TG and FFA in the eWAT (e) and liver (h) of mice. (f, i) The mRNA expression of lipogenesis and lipolysis associated genes in the eWAT (f) and liver (i). ATGL, adipose triglyceride lipase; BSA, bovine serum albumin; eWAT, epididymal white adipose tissue; FFA, free fatty acid; HFD, high-fat diet; IL, interleukin; NCD, normal chow diet; PBS, phosphate-buffered saline; qPCR, quantitative real-time PCR; TG, triglyceride.
