Proteome comparisons reveal influence of different dietary proteins on the development of rat jejunum

This study compared proteome profiles and morphological changes of rat jejunum in response to different dietary proteins. Fifty male Sprague-Dawley rats were fed with casein (control), and isolated beef, pork, fish and chicken proteins for 14 days. Proteome analysis, histological observation and PEPT1 quantification of the jejunum were performed. The results indicated that rats fed with chicken proteins had higher PEPT1 mRNA and protein levels (P<0.05) but lower villus height and ratio of villus height to crypt depth (V/C ratio, P<0.05) than those fed with casein and pork protein. Label-free LC-MS/MS indicated that, as compared to casein, intake of chicken protein can regulate oligopeptide transport mainly by upregulating PEPT1 protein expression and reducing dipeptidyl-peptidase activity related to biological oxidation, and can reduce oligopeptide absorption capacity by regulating Hippo signaling pathway. Although intake of beef and fish proteins had no significant effect on PEPT1 expression, they altered several signaling pathways