Fast & fuelious: the malate-aspartate shuttle in brown adipocyte lipid metabolism

Brown adipose tissue (BAT) produces heat in response to cold exposure, for which it relies on the coordination of aerobic and anaerobic metabolism. However, how reaction intermediates connect these two essential pathways is unclear. In this issue of The FEBS Journal, Veliova et al., report that the malate-aspartate shuttle (MAS) supports norepinephrine-induced lipolysis in brown adipocytes. Disruption of MAS during adrenergic activation impairs lipolysis without reducing respiration. These findings indicate that cytosolic redox balance influences thermogenic metabolism. By linking NAD+ regeneration to lipid metabolism, the study highlights the MAS as an important node coordinating metabolism, redox balance, and thermogenesis.