Effects of starvation-refeeding on antioxidant status, metabolic function, and adaptive response in the muscle of Cyprinus carpio

Abstract

The starvation-refeeding in fish has garnered significant attention, yet the molecular mechanisms underlying the treatment remain incompletely understood. This study aimed to evaluate the alterations in antioxidant status, metabolic function, and adaptive responses in Cyprinus carpio after starvation-refeeding, and to elucidate the underlying molecular mechanisms of adaptation to starvation using biochemical and transcriptomic analyses. Common carp were divided into two groups: a normal control group (NC) fed a commercial diet for 28 days, and a starvation-refeeding group (SR) experiencing 14 days of starvation followed by 14 days of refeeding. The findings indicated that starvation induced oxidative stress, as evidenced by decreased levels of total antioxidant capacity (T-AOC) and glutathione peroxidase (Gpx), alongside increased levels of glutathione-S-transferase (GST), superoxide dismutase (SOD), and malondialdehyde (MDA). Transcriptome analysis revealed that starvation resulted in the differential expression of 2001 genes, including 1259 upregulated and 742 downregulated genes. These differentially expressed genes (DEGs) were significantly enriched in the biosynthesis of amino acids and fatty acid degradation pathways. Furthermore, pathways associated with adaptive responses, including mitophagy, DNA replication, and protein processing in the endoplasmic reticulum (ER), exhibited marked changes following starvation. Additionally, the FoxO and p53 signaling pathways were involved in regulating the physiological adaptations to cope with starvation. Notably, after 14 days of refeeding, most oxidative stress parameters and gene expression profiles in the muscle of common carp returned to normal values. These findings offer new insights into the mechanisms of starvation stress in fish.