Transcriptome analysis provides novel insights into the function of PI3K/AKT pathway in maintaining metabolic homeostasis of Chinese perch muscle

Abstract

Skeletal muscle exhibits significant dynamism and plasticity over the fish life cycle. However, the molecular mechanism of dynamic regulation of metabolic homeostasis in fish skeletal muscle remains unclear. PI3K/AKT signaling plays a central role in cellular physiology by mediating growth factor signals during organismal growth and critical cellular processes. In order to reveal the role of PI3K/AKT signaling pathway in metabolic regulation of Chinese perch muscle, Illumina sequencing technology was preformed to mine the alterations of muscle transcriptome under PI3K inhibitor (LY294002) treatment. Total 619 unigenes were identified as significantly differentially expressed genes (DEGs) between the control and LY294002 treatment groups. Functional enrichment analysis revealed that DEGs were mostly associated with metabolic homeostasis, such as Biosynthesis of amino acids, Glycolysis/gluconeogenesis, Glycerolipid metabolism process. Furthermore, the histological section analysis showed that the spaces between muscle fibers in LY294002 injection group were increased and the cytoplasmic contents were reduced, which was consistent with the characteristics of muscle atrophy. Together with the results, it was suggested that the PI3K/AKT signaling pathway plays a crucial role in maintaining the balance of metabolism in fish muscle, which in turn ensures normal muscle physiology and growth. In addition, this study could provide a direction for the future research of elucidating the molecular mechanisms of metabolic homeostasis of PI3K/AKT signaling in fish muscle.