Proteomic analysis of glutamine-treated human intestinal epithelial HCT-8 cells under basal and inflammatory conditions

Glutamine (Gln) promotes intestinal growth and maintains gut structure and function, especially in situations of injury and during inflammation. Several mechanisms could contribute to Gln protective effects on gut. Proteomics enable us to characterize differentially expressed proteins in tissues in response to modifications of the biological or nutritional environment. Gln effects on the human intestinal epithelial HCT-8 cell line proteome were assessed under basal and proinflammatory conditions. The 2-DE gels were obtained and compared. Proteins were identified by MS and using databases. About 1200 spots were detected in both 2- and 10-mM Gln concentrations. Under basal conditions, 24 proteins were differentially expressed in response to Gln. Half of these proteins were implicated in protein biosynthesis or proteolysis and 20% in membrane trafficking. Under proinflammatory conditions, 27 proteins were up- or down-regulated by Gln 10 mM. From these proteins, 40% were involved in protein biosynthesis or proteolysis, 16% in membrane trafficking, 8% in cell cycle and apoptosis mechanisms and 8% in nucleic acid metabolism. This study provides the first holistic picture of proteome modulation by Gln in a human enterocytic cell line under basal and proinflammatory conditions, and supports further evaluation of nutritional modulation of intestinal proteome in humans.