Glucocorticoid resistance remodels liver lipids and prompts lipogenesis, eicosanoid, and inflammatory pathways

Area of Science:

• Biochemistry
• Molecular Biology
• Metabolic Diseases

Background:

• Glucocorticoid receptor beta (GRβ) is known to induce hepatic steatosis.
• GRβ inhibits the primary glucocorticoid receptor alpha (GRα), leading to glucocorticoid resistance.

Purpose of the Study:

• To investigate the specific effects of GRβ on hepatic lipid classes and molecular species.
• To understand the role of GRβ in regulating lipids that contribute to metabolic dysfunction.

Main Methods:

• Adenovirus-mediated overexpression of GRβ (GRβ-Ad) and a control vector (Vec-Ad) in mice.
• Analysis of liver lipid profiles using liquid chromatography-mass spectrometry (LC-MS).
• Assessment of gene expression related to lipogenesis, eicosanoid synthesis, and inflammation.

Main Results:

• GRβ overexpression significantly altered the hepatic lipidome, with notable increases in monoacylglycerides and cholesterol esters.
• GRβ-Ad mice exhibited increased gene expression in lipogenesis, eicosanoid synthesis, and inflammatory pathways.
• These molecular changes correlate with GRβ-induced hepatic fat accumulation.

Conclusions:

• GRβ plays a critical role in regulating hepatic lipid metabolism and promoting fat accumulation.
• GRβ-induced glucocorticoid resistance is linked to significant changes in lipid species and metabolic pathways.
• Targeting GRβ may offer novel therapeutic approaches for managing hepatic steatosis and related metabolic disorders.