MiR-124 Inhibits Lipid Deposition in Mouse Liver by Targeting the Trib3/Hnf4α Pathway

Area of Science:

• Molecular Biology
• Hepatology
• Metabolic Diseases

Background:

• Non-alcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by disrupted lipid homeostasis in the liver.
• Current therapeutic options for NAFLD are limited, necessitating the identification of novel regulatory pathways and targets.
• Previous research indicated miR-124's role in inhibiting adipogenesis and its association with altered lipid profiles.

Purpose of the Study:

• To investigate the function of miR-124 in hepatic lipid metabolism.
• To elucidate the molecular mechanism underlying miR-124's regulation of liver fat accumulation.
• To explore the potential of the miR-124 pathway as a therapeutic strategy for NAFLD.

Main Methods:

• Utilized in vitro models of hepatocyte lipid deposition and overexpression/inhibition of miR-124.
• Analyzed gene expression related to fatty acid metabolism, including uptake, synthesis, oxidation, and lipolysis.
• Employed miR-124 promoter knockout mice to validate findings in vivo and identified Tribbles homolog 3 (Trib3) and hepatocyte nuclear factor 4α (Hnf4α) as key players.

Main Results:

• miR-124 expression was found to be downregulated in a lipid deposition model.
• Overexpression of miR-124 suppressed lipid deposition by modulating genes involved in fatty acid metabolism and VLDL secretion.
• miR-124 directly targets Trib3, negatively regulating its expression and subsequently upregulating Hnf4α, a critical factor for lipid homeostasis. Conversely, miR-124 inhibition exacerbated steatosis.

Conclusions:

• The miR-124/Trib3/Hnf4α axis represents a novel regulatory pathway in hepatic lipid metabolism.
• Dysregulation of this axis contributes to lipid accumulation in the liver.
• Targeting the miR-124 pathway holds promise for developing new therapeutic interventions for NAFLD.