Fig 2: The effects of Astragaloside IV (AST) on lipolysis, lipase and respiratory quotient (RQ) in ageing mice. (A) The release of glycerol from visceral adipose tissue of mice in each group. (B) The phosphorylation status and the total protein levels of HSL and ATGL of visceral adipose tissue of mice in each group detected by Western blot. (C) The average weekly change in respiratory quotient (RQ) at 9 weeks after AST administration. The results are expressed as mean ± SD, *p < 0.05, # p < 0.05 vs ageing group (n = 10)

Fig 3: r-sFNDC5 induced the browning and lipolysis of 3T3-L1 adipocytes. The biological activity of purified r-sFNDC5 was assessed in differentiated 3T3-L1 adipocytes. (A) 3T3-L1 preadipocytes were treated with various concentrations of r-sFNDC5 for the indicated times, and cell viability was assessed using a CCK-8 assay. The data are expressed as OD values at 450 nm. After fully differentiating, mature 3T3-L1 adipocytes were treated with r-sFNDC5 (20 nM and 50 nM) for 8 h. Then, the relative mRNA levels of browning genes (B) and lipolysis genes (C) were measured by RT–qPCR, and (D, E) western blotting was performed for UCP-1 and HSL. ß-actin expression was used as a control. (F) Representative 3T3-L1 adipocytes immunostained for UCP-1 (green) and nuclei (blue) after r-sFNDC5 (50 nM) treatment for 24 h or 4 days. White arrows indicate UCP-1-positive cells. Images were taken using a confocal fluorescence microscope. (G) ATP levels measured in lysates of 3T3-L1 adipocytes treated with 20-100 nM r-sFNDC5 for 4 days. ATP concentrations were normalized to protein content and control. Each experiment was repeated three times. Values are the mean ± SEM. *P < 0.05, **P < 0.01 and ***P < 0.001 vs. control.

Fig 4: The function comparison of r-sFNDC5 and r-irisin in the 3T3-L1 adipocytes. After fully differentiated, 3T3-L1 adipocytes were treated with r-sFNDC5 (20 nM) or r-irisin (20 nM) for 8 h. (A) Relative mRNA levels of browning genes, (B) mitochondrial biogenesis, and (C) lipid metabolism were measured by RT–qPCR. (D) The contents of UCP-1 and HSL were measured using western blotting. ß-actin expression was used as a control. The asterisk (*) above the bar denotes statistically significant differences in mRNA levels calculated relative to the control, while the hash (#) denotes statistically significant differences calculated between the irisin and sFNDC5 groups. Each experiment was repeated three times. Values are the mean ± SEM. *P < 0.05 vs. control, #P < 0.05 vs. irisin.

Fig 5: Influence of PN supplementation in the diet of sows from 85 d of gestation to parturition on the protein expression of key enzymes for lipid metabolism in liver of neonatal piglets. Data are presented as mean ± SEM, n = 3. Statistical significance was were set at *P < 0.05. AKT = protein kinase B; P-AKT = phosphorylated protein kinase B; HSL = hormone-sensitive lipase; P-HSL = phosphorylated HSL; SREBP-1c = sterol regulatory element binding transcription factor 1c; CYP27A1 = cytochrome P450 family 27 subfamily a member 1; GADPH = glyceraldehyde-3-phosphate dehydrogenase; PN = pyrimidine nucleoside.