Hepatic lipid accumulation: cause and consequence of dysregulated glucoregulatory hormones

Area of Science:

• Hepatology
• Endocrinology
• Metabolic Syndrome

Background:

• Fatty liver, induced by various factors, causes systemic metabolic dysfunction.
• Hepatic lipid accumulation alters gene expression via peroxisome proliferator-activated receptor (PPAR) ligands, promoting hyperglycemia, hyperlipidemia, and ketosis.
• The hormonal milieu in fatty liver disease involves hyperinsulinemia, hyperglucagonemia, and other imbalances that exacerbate hepatic steatosis.

Purpose of the Study:

• To review the hormonal regulation of four key mechanisms of hepatic lipid accumulation.
• To compare physiological models of fatty liver disease.
• To highlight the role of hepatic steatosis in driving systemic metabolic dysfunction.

Main Methods:

• Review of literature on hormonal regulation of hepatic lipid metabolism.
• Comparison of physiological models of hepatic lipid accumulation.
• Analysis of gene expression changes related to peroxisome proliferator-activated receptor (PPAR) signaling.

Main Results:

• Hepatic lipid accumulation can result from increased fatty acid uptake, increased de novo lipogenesis (DNL), decreased beta-oxidation, or decreased lipid export.
• Hormonal and metabolic changes in fatty liver disease promote hepatic steatosis through various pathways.
• Nonalcoholic fatty liver disease (NAFLD) involves altered hepatic lipid uptake, synthesis, oxidation, and export.

Conclusions:

• Hepatic steatosis is a central driver of systemic metabolic dysfunction across diverse etiologies.
• Understanding the mechanisms of metabolic dysfunction in fatty liver is crucial for identifying therapeutic targets.
• Targeting hormonal regulation of hepatic lipid metabolism may offer intervention points for fatty liver disease.