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Updated: Jan 3, 2026

Measurement of Fatty Acid β-Oxidation in a Suspension of Freshly Isolated Mouse Hepatocytes
Published on: September 9, 2021
Liver-derived FGF21 is essential for full adaptation to ketogenic diet but does not regulate glucose homeostasis
Mikiko Watanabe1,2, Garima Singhal1, Ffolliott M Fisher1
1Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02215, USA.
Background:
Fibroblast growth factor 21 (FGF21) is expressed in several metabolically active tissues, including liver, fat, and acinar pancreas, and has pleiotropic effects on metabolic homeostasis. The dominant source of FGF21 in the circulation is the liver.
Objective And Methods:
To analyze the physiological functions of hepatic FGF21, we generated a hepatocyte-specific knockout model (LKO) by mating albumin-Cre mice with FGF21 flox/flox (fl/fl) mice and challenged it with different nutritional models.
Results:
Mice fed a ketogenic diet typically show increased energy expenditure; this effect was attenuated in LKO mice. LKO on KD also developed hepatic pathology and altered hepatic lipid homeostasis. When evaluated using hyperinsulinemic-euglycemic clamps, glucose infusion rates, hepatic glucose production, and glucose uptake were similar between fl/fl and LKO DIO mice.
Conclusions:
We conclude that liver-derived FGF21 is important for complete adaptation to ketosis but has a more limited role in the regulation of glycemic homeostasis.
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