Proteomic Analysis of Colon Tissue from Interleukin-10 Gene-Deficient Mice Fed Polyunsaturated Fatty Acids with Comparison to Transcriptomic Analysis

Inflammatory bowel disease (IBD) is characterized by intestinal inflammation and is believed to involve complex interactions between genetic, immunological, and environmental factors. We measured changes in the proteome associated with bacterially induced intestinal inflammation in the interleukin 10 gene-deficient (Il10(-/-)) mouse model of IBD, established effects of the dietary polyunsaturated fatty acids (PUFAs) n-3 eicosapentaenoic acid (EPA) and n-6 arachidonic acid (AA) on protein expression (using oleic acid as a control fatty acid), and compared these changes with previously observed transcriptome changes in the same model. Ingenuity pathways analysis of proteomics data showed bacterially induced inflammation was associated with reduced expression of proteins from pathways of metabolism and digestion/absorption/excretion of nutrients/ions, and increased expression of cellular stress and immune response proteins. Both PUPA treatments showed anti-inflammatory activity; EPA appeared to act via the PPAR alpha pathway, whereas AA appeared to increase energy metabolism and cytoskeletal organization and reduce cellular stress responses, possibly enabling a more robust response to inflammation. While there was agreement between proteomic and transcriptomic data with respect to pathways, there was limited concordance between individual gene and protein data, reflecting the importance of having both gene and protein data to better understand complex diseases such as IBD.