Metabolomic Alterations in Mammary Glands from Pubertal Mice Fed a High-Fat Diet

Dietary malpractice is a risk factor for obesity. This study tested the hypothesis that consumption of a high-fat diet alters mammary metabolome in pubertal mice. We performed untargeted metabolomic analysis of primary metabolism on mammary glands from pubertal mice fed the AIN93G standard diet or a high-fat diet (HFD) for 3 weeks. We identified 97 metabolites for statistical comparisons. The HFD altered the amino acid metabolism considerably. This included elevated expression of branched-chain amino acids, non-essential amino acids (aspartic acid and glutamic acid), and methionine sulfoxide (oxidized methionine) and an alteration in the aminoacyl-tRNA biosynthesis pathway. Furthermore, elevations of fumaric acid and malic acid (both are citrate cycle intermediates) and glyceric acid (its phosphate derivatives are intermediates of glycolysis) in HFD-fed mice suggest an acceleration of both citrate cycle and glycolysis. Lower expression of glycerol, oleic acid, and palmitoleic acid, as well as decreased mammary expression of genes encoding lipid metabolism (Acaca, Fads1, Fasn, Scd1, and Srebf1) in HFD-fed mice indicate an attenuated lipid metabolism in the presence of adequate dietary fat. In conclusion, consumption of the HFD for 3 weeks alters metabolic profile of pubertal mammary glands. This alteration may affect mammary development and growth in pubertal mice.