Clues from the intestinal mucus proteome of Atlantic salmon to counter inflammation

Intestinal inflammation in Atlantic salmon was studied by profiling the intestine mucus proteome, employing isobaric tags for relative and absolute quantification and 2D LC-MS/MS approach. Two fish groups were fed soy saponin-containing (inflammation inducer, SO) or devoid (CO) diets for 36 days. Two more fish groups were fed each of the aforementioned diets with a health additive (CP, SP). Inflammation characteristics in the intestine were milder in the SP-fed fish compared to the SO-fed fish, based on histology results. The fish that had intestinal inflammation (SO) was characterised by alterations of many proteins. Based on the enriched KEGG pathways and GO terms of the SO vs CO comparison pathways such as phagosome and lipid binding were affected due to upregulation of protein like Integrin beta 2 precursor, Coronin 1A, Cathepsin S precursor, Vesicle-trafficking protein, and Neutrophil cytosol factors. On the other hand, the SP group had fewer inflammation characteristics and altered proteins; this fish group had higher abundance of protein linked to the pathways aminoacyl-tRNA biosynthesis and ribosome due to the higher abundance of many large and small subunit of ribosomes. The alteration of Glycogen phosphorylase and Glutamin synthetase could also have alleviated intestinal inflammation in the SP group. Elevating the abundance of ribosomal proteins, aminoacyl-tRNA ligases, and lowering the abundance of Glycogen phosphorylase and Glutamine synthetase could be effective to alleviate intestinal inflammation. The proteins described here can be exploited to alleviate intestinal inflammation in fish and higher vertebrates.