Agpat2, encoding 1-acylglycerol-3-phosphate O-acyltransferase 2, is an intermediate enzyme in triglyceride synthesis [4]. It catalyzes the acylation of lysophosphatidic acid to form phosphatidic acid (PA), a key step in the glycerol-3-phosphate pathway for the synthesis of phospholipids and triacylglycerols [1]. This process is crucial for lipid metabolism and related biological processes. Genetic models, such as gene knockout mouse models, are valuable for studying Agpat2.

In Agpat2 knockout (Agpat2-/-) mice, several significant phenotypes are observed. These mice show severe loss of adipose tissue and fatty liver [2]. When crossed with Ldlr-/-mice, Agpat2-/-Ldlr-/-mice exhibit more severe hyperlipidemia, hyperglycemia, hyperinsulinemia, liver fibrosis, and aggravated atherosclerosis compared to Ldlr-/-mice [2]. Agpat2-/-mice also completely lack both white and interscapular brown adipose tissue (iBAT), and differentiated Agpat2-/-brown adipocytes have fewer lipid-laden cells, lower abundance of key adipogenic transcription factors, increased expression of interferon-stimulated genes, and altered mitochondrial morphology [3]. In addition, adipocytes from Agpat2-/-mice have impaired adipogenesis and fewer caveolae, and abnormal lipid composition without preventing insulin signaling [5]. Postnatal cell death of adipose tissue associated with acute local inflammation leads to lipodystrophy in Agpat2-/-mice, and re-expressing human AGPAT2 in Agpat2-null mice can result in partial regeneration of adipose tissue, indicating the essential role of Agpat2 in adipocyte differentiation [6,7].

In conclusion, Agpat2 is essential for normal lipid metabolism, adipogenesis, and the maintenance of adipose tissue. Studies using Agpat2 KO mouse models have revealed its significant role in diseases such as hyperlipidemia, atherosclerosis, and lipodystrophy. Understanding Agpat2 function provides insights into the mechanisms of these disease conditions and may offer potential therapeutic targets.