Fig. 3: Elevated release of xanthine and hypoxanthine in response to obesity by adipocytes is limited by autophagy.
From: Autophagy acts as a brake on obesity-related fibrosis by controlling purine nucleoside signalling
A, B Concentration of serum xanthine and hypoxanthine in WT mice were fed NCD or HFD for 10, 30 or 60 weeks (A) or WT and Atg7Ad mice fed with HFD for 16 weeks (B). n = 5 (HFD60, B-WT), 6 (B-Atg7Ad), 8 (HFD10, HFD30, NCD10) and 9 (NCD30, NCD60) mice. C Relative abundance of nucleosides released by gWAT adipocytes isolated from WT and Atg7Ad mice following HFD feeding for 16 weeks and measured in metabolomics analysis. n = 3 mice. D Concentration of xanthine and hypoxanthine released from gWAT adipocytes cultured over 24 h ex vivo. Adipocytes were isolated as in (C). n = 5 (WT) and 6 (Atg7Ad) mice. E Correlation analysis of the level of autophagy flux in gWAT and concentration of xanthine and hypoxanthine released from gWAT adipocytes as in (D). Western blot analysis of autophagy flux was calculated as (LC3-II (Inh) – LC3-II (Veh)). n = 9 mice. F Concentration of xanthine and hypoxanthine as in (D) treated with either PBS or 10 µM forodesine, a purine nucleoside phosphorylase (PNP) inhibitor. n = 6 mice. G Concentration of xanthine and hypoxanthine released from gWAT explants cultured overnight ex vivo and treated with either DMSO or 20 µM Q-VD-OPh, a pan-caspase inhibitor. n = 5 (Atg7Ad) and 6 (WT) mice. H Concentration of xanthine and hypoxanthine after treatment of gWAT explants with DMSO or 10 µM staurosporine (STS), an apoptosis inducer, for 24 h ex vivo. n = 11 mice. I Concentration of released xanthine and hypoxanthine from gWAT explants after cell lysis with 0.1 % Triton-X for 1 h before the end of incubation. n = 4 mice. Data are presented as mean ± SD. Dots represent individual biological replicates. Data are representative (D, I) or merged from 2 to 3 independent experiments (A, B, E–H). Statistical analysis by two-way ANOVA with Tukey multi comparisons (A), Mann–Whitney test (B), unpaired t-test (D), Pearson R correlation analysis (E), Fisher test (F) or Šídák multi comparisons test (I).
