Transcriptomic and Metabolomic Analysis Reveals the Impact of Autophagy Regulation on Purine Content in Mutton

Background: Excessive purine intake increases the risk of hyperuricemia and gout. This study investigates the relationship between purine content in mutton and meat quality traits and explores the regulatory mechanism of purine metabolism through transcriptomic and metabolomic analyses. Methods: Thirty-six-month-old hybrid sheep (Australian White × Small-tail Han) were selected. Purine content and meat quality traits, including inosine monophosphate (IMP), intramuscular fat (IMF), shear force, pH, cooking loss, and meat color, were measured. Transcriptomic sequencing and metabolomic analysis were performed on muscle samples with high (3895.70 ± 107.03 mg/kg) and low (2751.72 ± 175.29 mg/kg) purine contents (n = 6 per group). Differentially expressed genes were validated by quantitative PCR and Western blot. In vivo autophagy regulation experiments were performed on mice using rapamycin (activator) and chloroquine (inhibitor). Results: No significant correlation was found between purine content and meat quality traits, suggesting that reducing purine content does not negatively affect mutton quality. An autophagy-related gene, LAPTM5 (lysosomal-associated protein transmembrane 5), was identified as a key gene negatively regulating purine content. In vivo autophagy regulation experiments demonstrated that autophagy affects purine metabolism by modulating key enzymes such as xanthine dehydrogenase (XDH) and hypoxanthine-guanine phosphoribosyltransferase 1 (HPRT). Conclusions: This study reveals the role of autophagy in regulating purine metabolism through the key enzymes XDH and HPRT, providing new insights for improving mutton quality in the future.