Hydrogen sulfide stimulates lipid biogenesis from glutamine that is dependent on the mitochondrial NAD(P)H pool.

Mammalian cells synthesize HS from sulfur-containing amino acids and are also exposed to exogenous sources of this signaling molecule, notably from gut microbes. As an inhibitor of complex IV in the electron transport chain, HS can have a profound impact on metabolism, suggesting the hypothesis that metabolic reprogramming is a primary mechanism by which HS signals. In this study, we report that HS increases lipogenesis in many cell types, using carbon derived from glutamine rather than from glucose. HS-stimulated lipid synthesis is sensitive to the mitochondrial NAD(P)H pools and is enabled by reductive carboxylation of α-ketoglutarate. Lipidomics analysis revealed that HS elicits time-dependent changes across several lipid classes, e.g., upregulating triglycerides while downregulating phosphatidylcholine. Direct analysis of triglyceride concentration revealed that HS induces a net increase in the size of this lipid pool. These results provide a mechanistic framework for understanding the effects of HS on increasing lipid droplets in adipocytes and population studies that have pointed to a positive correlation between cysteine (a substrate for HS synthesis) and fat mass.