Acute Fasting Induces Expression of Acylglycerophosphate Acyltransferase (AGPAT) Enzymes in Murine Liver, Heart, and Brain

Abstract

During fasting, cells increase uptake of non-esterified fatty acids (NEFA) and esterify excess into phosphatidic acid (PtdOH), the common precursor of both triacylglycerols and phospholipids, using acylglycerophosphate acyltransferases/lysophosphatidic acid acyltransferases (AGPAT/LPAAT). Knowledge of the regulation of AGPAT enzymes is important for understanding fasting adaptations. Total RNA was isolated from liver, heart, and whole brain tissue of C57BL/6J mice fed ad libitum, or fasted for 16 h. Following fasting, induction of Agpat2, 3, 4, and 5 was observed in the liver, Agpat2 and 3 in heart tissue, and Agpat1, 2, and 3 in whole brain tissue. As a result, the relative abundance profile of the individual homologues within specific tissues was found to be significantly altered depending on the nutritive state of the animal. These data demonstrate tissue-specific effects of fasting on the regulation of different Agpat that are implicated in supporting unique downstream glycerolipid synthesis pathways.