Fig. 6: GSNOR decreases Beclin-1 S-nitrosation and promotes autophagy.

a Schematic representation of the experimental approach for quantitative S-nitrosation proteome in iWAT from 3-month-old male control and KI mice (n = 3). b Top-ranked S-nitrosation proteins of quantitative S-nitrosation proteome. c Quantitative S-nitrosation proteomic mass showing the identification of the S-nitrosation site at cysteine 351 in Beclin-1 peptides. d Immunoblotting for SNO-Beclin-1 levels in iWAT from 3-month-old male control and KI mice (n = 3 biological replicates). e Immunoblotting for SNO-Beclin-1 levels in iWAT from 11-month-old male WT and KO mice (n = 6 biological replicates). f Immunoblotting for SNO-Beclin-1 levels in iWAT from young and middle-aged male mice (n = 3 biological replicates). g Immunoblotting for P62 protein levels in iWAT from WT and KO mice (n = 3 biological replicates). h Electron micrographs in iWAT from 3-month-old male WT and KO mice harvested at 2 days of cold exposure withdrawal. Red arrows denote autophagosomes, and the letter L denotes lipid droplets. White scale bar, 1 μm. Black scale bar, 200 nm. Images were acquired from 5 random fields per mouse (n = 4 per group). i Immunoblotting for P62 protein levels in iWAT from control and KI mice at 2 days of cold exposure withdrawal (n = 3 biological replicates). Data are represented as mean ± SD; Significance was assessed by unpaired two-tailed Student’s t test (d, e, f, g, i) (*p < 0.05, **p < 0.01, ***p < 0.001). iWAT inguinal white adipose tissue, WT wild-type, KO GSNOR knockout.