S-nitrosoglutathione reductase GSNOR drives age-related obesity by promoting adipose tissue whitening through de-nitrosation of Beclin-1

Age-related obesity is a growing public health concern linked to various metabolic disorders, yet its underlying mechanisms remain incompletely understood. Here we report that S-nitrosoglutathione reductase (GSNOR), a pivotal denitrosation enzyme, increases in adipose tissue of both male mice and humans from middle-age. GSNOR knockout protects against age-related weight gain and enhances metabolism, whereas adipose-specific GSNOR knock-in mice promotes obesity and metabolic decline. Further investigation reveals that aged GSNOR KO mice maintain higher mitochondrial content and more beige adipocytes, whereas adipose-specific GSNOR overexpression promotes adipose tissue whitening. Mechanistically, GSNOR denitrosates Beclin-1 at cysteine 351 and mutation of this site (Beclin-1C351A) increases autophagy by enhancing Beclin-1 and ATG14 interaction, thereby accelerating beige-to-white adipocyte conversion. Together, our findings reveal that GSNOR regulates adipose tissue remodeling during aging through Beclin-1 S-nitrosation, pointing to a potential therapeutic target for age-related obesity. Age-related obesity is a major health issue with unclear causes. This work reveals that the enzyme GSNOR promotes obesity by reducing mitochondria in fat, leading to tissue “whitening” and identifying it as a potential therapeutic target.