Fructose and follistatin potentiate acute MASLD during complete hepatic insulin resistance
Related Experiment Video
Updated: Jan 10, 2026

Mouse Model of Metabolic Dysfunction-Associated Steatotic Liver Disease with Fibrosis
Published on: July 18, 2025
Rongya Tao1, Oliver Stöhr1, Ozlem Tok2
1Division of Endocrinology Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
Abstract:
MASLD (metabolic-associated steatotic liver disease) and MASH (steatohepatitis) are closely associated with hepatic IR (insulin resistance) and T2D. Regardless, insulin-stimulated hepatic lipogenesis is considered essential for MASLD development, as mouse models of complete hepatic IR become diabetic without MASLD when fed high-fat diets. Challenging this notion, we found that male LDKO mice lacking hepatic insulin receptor substrates acutely developed MASLD if fed a fructose-enriched "MASH diet" (GAN) or high-fructose diet. Fructose potentiated hepatic re-esterification of abundant circulating fatty acids in LDKO mice, evidenced by excess 13C incorporation into the glycerol backbone-but not fatty acid chains-of hepatic triacylglyceride after gavage with [U13C]fructose. Suppressing adipose lipolysis in LDKO mice by inactivating hepatic Fst (Follistatin) prevented acute MASLD, whereas over-expressing Fst in wild-type mouse liver accelerated GAN-promoted MASLD/MASH. Compatibly, higher serum FST levels among Tübingen Diabetes Family Study participants clustered with increased adipose IR and greater hepatic triacylglyceride accumulation.
Insights
Metabolic-associated steatotic liver disease (MASLD) can develop without insulin resistance, driven by fructose metabolism. Follistatin (FST) promotes MASLD by increasing hepatic fat accumulation, even without insulin signaling.
Area of Science:
- Hepatology
- Metabolic Syndrome
- Endocrinology
Background:
- Metabolic-associated steatotic liver disease (MASLD) and steatohepatitis (MASH) are linked to hepatic insulin resistance (IR) and type 2 diabetes (T2D).
- Hepatic lipogenesis stimulated by insulin is traditionally considered crucial for MASLD development.
Purpose of the Study:
- To investigate the role of fructose metabolism and insulin signaling in MASLD pathogenesis.
- To challenge the established notion that insulin-stimulated hepatic lipogenesis is essential for MASLD development.
Main Methods:
- Utilized male liver-direct knockout (LDKO) mice lacking hepatic insulin receptor substrates.
- Administered fructose-enriched diets (MASH diet/GAN or high-fructose diet).
- Traced hepatic triacylglyceride synthesis using [U-13C]fructose and assessed the impact of Follistatin (Fst) manipulation on MASLD development.
Main Results:
- LDKO mice developed acute MASLD when fed fructose-enriched diets, despite complete hepatic IR.
- Fructose enhanced hepatic re-esterification of circulating fatty acids in LDKO mice.
- Inactivating hepatic Fst prevented MASLD in LDKO mice, while Fst overexpression accelerated MASLD/MASH in wild-type mice.
- Elevated serum FST levels correlated with increased adipose IR and hepatic triacylglyceride accumulation in human study participants.
Conclusions:
- Insulin-stimulated hepatic lipogenesis is not essential for MASLD development.
- Fructose metabolism plays a critical role in promoting MASLD, particularly in the context of hepatic insulin resistance.
- Follistatin (FST) acts as a key mediator in MASLD pathogenesis by potentiating hepatic fat accumulation.
More Related Videos
07:03Author Spotlight: Establishing MASLD Cell Models for Investigating Disease Mechanisms and the Lipid-Lowering Effects of Koumiss
Published on: July 19, 2024
08:32Studying the Hypothalamic Insulin Signal to Peripheral Glucose Intolerance with a Continuous Drug Infusion System into the Mouse Brain
Published on: January 4, 2018
Related Concept Videos
Oral Hypoglycemic Agents: Biguanides and Glitazones
Insulin: The Receptor and Signaling Pathways
Oral Hypoglycemic Agents: α-Glucosidase Inhibitors
Acarbose and miglitol are...
Glucagon-like Receptor Agonists
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are...
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...