Regulation of fatty acid trafficking in liver by thioesterase superfamily member 1
Publication Type | Academic Article |
Authors | Desai A, Alves-Bezerra M, Ozdemir C, Bare CJ, Li Y, Hagen SJ, Cohen DE |
Journal | J Lipid Res |
Volume | 59 |
Issue | 2 |
Pagination | 368-379 |
Date Published | 12/05/2017 |
Abstract | Thioesterase superfamily member 1 (Them1) is an acyl-CoA thioesterase that is highly expressed in brown adipose tissue, where it functions to suppress energy expenditure. Lower Them1 expression levels in the liver are upregulated in response to high-fat feeding. Them1-/- mice are resistant to diet-induced obesity, hepatic steatosis, and glucose intolerance, but the contribution of Them1 in liver is unclear. To examine its liver-specific functions, we created conditional transgenic mice, which, when bred to Them1-/- mice and activated, expressed Them1 exclusively in the liver. Mice with liver-specific Them1 expression exhibited no changes in energy expenditure. Rates of fatty acid oxidation were increased, whereas hepatic VLDL triglyceride secretion rates were decreased by hepatic Them1 expression. When fed a high-fat diet, Them1 expression in liver promoted excess steatosis in the setting of reduced rates of fatty acid oxidation and preserved glycerolipid synthesis. Liver-specific Them1 expression did not influence glucose tolerance or insulin sensitivity, but did promote hepatic gluconeogenesis in high-fat-fed animals. This was attributable to the generation of excess fatty acids, which activated PPARα and promoted expression of gluconeogenic genes. These findings reveal a regulatory role for Them1 in hepatocellular fatty acid trafficking. |
DOI | 10.1194/jlr.M081455 |
PubMed ID | 29208699 |
PubMed Central ID | PMC5794430 |