Transcriptome and metabolite profiling reveals the mechanism of hepatic lipid metabolism during fasting in chicken

Objective: Since the liver is key to poultry lipid metabolism and fasting models are widely used in studying animal nutrition metabolism, this study used fasting to explore chicken liver lipid metabolism characteristics, providing a basis for poultry lipid metabolism research.Methods: RNA-seq and metabolomics were combined to analyze 72-hour fasting effects on chicken liver lipid metabolism. Key lipid metabolism-related genes and metabolites were identified, with their mechanisms explored via RNAi and Oil Red O staining.Results: Metabolomics identified 648 differential metabolites, including 8 (e.g., Arachidonoyl amine) with levels 160-fold higher than controls. Transcriptomics found 849 differentially expressed genes (DEGs), 78 involved in lipid metabolism; Protein–protein interaction analysis revealed hub genes like EHHADH. Transcriptome-metabolome correlation analysis showed 101 DEGs correlated with 99 metabolites, with EHHADH associated with 54 metabolites (the most) and linked to 2-methylcrotonoyl-CoA and 5 pathways via KEGG Markup Language. Fasting upregulated EHHADH, whose overexpression/interference altered mRNA levels of Fabp7, Plin2, ACACA, FASN, PPARα, as well as cholesterol/triglyceride levels. EHHADH overexpression reduced LMH cell lipid deposition, while interference increased it, indicating its role in reducing lipid deposition.Conclusion: Fasting significantly alters chicken liver lipid metabolism, and EHHADH helps reduce liver lipid deposition.