Effects of glucose on biochemical immune responses and hepatic gene expression in common carp, Cyprinus carpio L

Glucose metabolism is a key biological process in animals, as it is related to multiple activities including immune response and diseases. In this study, we focused on serum parameter changes and hepatic gene expression to explore the immune response to glucose injection. We performed serum analysis and high-throughput sequencing analysis in the liver of common carp (Cyprinus carpio L). The serum GLU and albumin were up-regulated by glucose injection. The transcriptome analysis showed that the categories of response to external stimulus in GO category, PPAR-signalling pathway, complement and coagulation cascades pathways in KEGG analysis were enriched in genes that were differently expressed between the glucose injection group and the control group. Among these pathways, redox-regulatory protein FAM213A-like, extracellular superoxide dismutase [Cu-Zn]-like and putative natural resistance-associated macrophage protein (NRAMP) were up-regulated by glucose stimulation. The 25-hydroxyvitamin D-1 alpha hydroxylase, vitamin D 25-hydroxylase and natterin-3-like were significantly down-regulated by glucose injection. The present study is the first report of serum and hepatic transcriptome changes in common carp in response to glucose increase in serum. The obtained data provide valuable clues for future efforts into understanding the connection between the energy metabolism and the immune system.