SIRT3 and obesity due to melanocortin 4 receptor deficiency: Here our results showed that BAT regional endothelium-specific Sirt3 loss not only resulted in vascular rarefaction but also promoted BAT whitening and obesity progression, emphasizing a critical role of BAT endothelial cells in modulating overall metabolism and suggesting that endothelial SIRT3 could be an efficient therapeutic target in modulating angiogenesis and adiposity.