SIRT3 and obesity due to melanocortin 4 receptor deficiency: Even though HFD-fed mice had lower SIRT3 expression in the heart, HFD did not further worsen the capillary rarefaction observed in Sirt3-KO hearts, suggesting SIRT3 loss to be one of the pathways implicated in obesity-induced capillary rarefaction and SIRT3′s potential as a therapeutic target in preserving heart capillary density upon obesity [115].