|Sun, Xiaofei - Washington State University|
|Du, Min - Washington State University|
|Navarre, Duroy - Roy|
|Zhu, Mei-jun - Washington State University|
Submitted to: Molecular Nutrition and Food Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/19/2017
Publication Date: 11/28/2017
Citation: Sun, X., Du, M., Navarre, D.A., Zhu, M. 2017. Purple potato extract promotes intestinal epithelial differentiation and barrier function by activating AMP-activated protein kinase. Molecular Nutrition and Food Research. 62(4).
Interpretive Summary: An abnormal intestinal epithelium, also called leaky gut, is associated with many diseases, including inflammatory bowel disease, metabolic syndrome, and autoimmune disorders. Scientists at Washington State University and the USDA-ARS in Prosser, WA examined the effect of extracts from high polyphenol purple potatoes on a tissue culture cell line and in a gut model. The potato extracts were found to strengthen the gut intestinal barrier, and this improvement was mediated through a protein known as AMPK. This work provides new insights into the mechanism responsible for the beneficial role of plant polyphenolic compounds in intestinal barrier function, and the findings suggest that purple potato consumption could be used as a supportive dietary therapeutic strategy for improving gut epithelial health.
Technical Abstract: Perturbation of the gut epithelial barrier function induces inflammation and other health problems that originate in the gut. Purple potato contains a high content of polyphenolic compounds known for beneficial effects. The objective of this study was to evaluate the effect of purple potato extract (PPE) on intestinal differentiation and barrier function, and explore its underlying mechanism using Caco-2 cells and ex vivo cultured gut tissues. PPE increased transepithelial electrical resistance and decreased FITC-dextran paracellular flux in Caco-2 cells, which were associated with strengthened intestinal epithelial differentiation in both Caco-2 cells and ex vivo guts. Furthermore, PPE treatment enhanced AMP-activated Protein Kinase (AMPK) activity, concomitant with increased expression of CDX2, a key transcriptional factor regulating intestinal epithelial differentiation. Knocking down AMPK using CRISPR/Cas9 system abolished the positive effects of PPE on intestinal epithelial differentiation and barrier function, in junction with reduced expression of CDX2. In conclusion, PPE improved gut epithelial differentiation and barrier function via activating AMPK.