Source: WASHINGTON STATE UNIVERSITY submitted to
PIGMENTED POTATO RESTORES GUT EPITHELIAL HEALTH IMPAIRED BY OBESITY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
Reporting Frequency
Annual
Accession No.
1014924
Grant No.
2018-67017-27517
Project No.
WNP03129
Proposal No.
2017-06996
Multistate No.
(N/A)
Program Code
A1341
Project Start Date
Mar 1, 2018
Project End Date
Feb 28, 2022
Grant Year
2018
Project Director
Zhu, M.
Recipient Organization
WASHINGTON STATE UNIVERSITY
240 FRENCH ADMINISTRATION BLDG
PULLMAN,WA 99164-0001
Performing Department
School of Food Science
Non Technical Summary
Obesity is a worldwide epidemic and is associated with serious health problems. The latter include impairment of gut barrier function, or "leaky gut", which is responsible for a number of diseases including gut inflammatory diseases and food allergies. Thus, there is an urgency to improve gut barrier function impaired due to obesity. Dietary polyphenols are known for their potent beneficial effects on health including gut epithelial health despite poorly defined mechanisms. As a staple food, potatoes can be an excellent source of dietary polyphenols. While white potatoes contain a modest amount of polyphenols, pigmented potatoes have high levels of chlorogenic acid and anthocyanins, both of which activate AMP-activated protein kinase (AMPK). We hypothesize that polyphenols of pigmented potato improve intestinal epithelial integrity and barrier function impaired by obesity via activating AMPK and associated signaling. We will use a whole food approach by feeding potatoes with different polyphenol contents to obese mice, in conjunction with genetically modified mouse and in vitro cell cultures for mechanistic exploration. The knowledge gained from these studies will promote the consumption of potato, benefiting a critical industry in Northwest. In addition, such knowledge can lead to novel dietary guidelines to prevent or mitigate gut health problems associated with obesity, thus generating large societal impacts.
Animal Health Component
100%
Research Effort Categories
Basic
70%
Applied
30%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7021310101050%
7021310102030%
7021310103020%
Goals / Objectives
Obesity affects more than one-third of the US population and is known to induce inflammation and impair intestinal epithelial development. Gut epithelium forms the largest, most critical and highly selective barrier in our body. Disturbances of intestinal barrier function allow the transmission of macromolecules and bacteria across the epithelial barrier, inducing inflammation and abnormal immune responses, which in turn further disrupt gut epithelial integrity and barrier function, forming a vicious cycle. Thus, it is vital to develop strategies that can protect or re-establish gut barrier function; however, our understanding of molecular mechanisms linking diet to epithelial barrier function remains rudimentary. Polyphenols are a large heterogeneous group of compounds occurring in plant foods, known for their preventive or therapeutic effects on metabolic diseases including obesity. Potatoes are one of the most widely consumed staple foods in the U.S. Pigmented potato contains high levels of both chlorogenic acid (CGA) and anthocyanins; however their relative contribution to gut epithelial health is unclear. AMP-activated protein kinase (AMPK) is as a master regulator of energy metabolism. Our preliminary studies showed that AMPK regulates intestinal epithelial cell differentiation and barrier function. These studies imply that AMPK may be a key mediator for the beneficial effects of potato polyphenols on gut epithelium. Our central hypothesis is that polyphenols of pigmented potato improve intestinal epithelial integrity impaired by obesity via activating AMPK and associated signaling. To test our central hypothesis, we will pursue two interrelated aims:Aim 1. Determine the impact of potato polyphenols on AMPK activation and gut epithelial development impaired due to obesity.Aim 2. Evaluate the mediatory role of AMPK in linking potato polyphenols to gut epithelial development and integrity.
Project Methods
Aim 1. Determine the impact of potato polyphenols on AMPK activation and gut epithelial development impaired due to obesity. We will use our unique potato cultivars, a white potato with low polyphenols, a pigmented potato (Purple Pelisse) rich in CGA and anthocyanins, and its corresponding CGA deficient potato. The diet-induced obesity mice model will be used in this study. This model mimics the typical Western diet and is very relevant to obesity in humans. Male C57BL/6J mice will be randomized to receive control diet (D12450J, Research Diets) with 10% energy from fat (CON) or an obesogenic diet (D12492, Research Diets) with 60% energy (OBE) for two months to develop obesity. Then, mice in the obesogenic group will be further separated into four treatments. As a result, there are five treatments: 1) Con diet without potato; 2) OBE without potato; 3) OBE+10% white potato; 4) OBE+10% purple potato; and 5) OBE+10% CGA deficient purple potato. Ten mice per dietary group will be used. Dietary potato treatments will last for 10 weeks. To avoid the potentially confounding effects of sex, only male mice will be used in the study. Fecal samples will be collected for gut microbiota pyrosequencing to comprehensively examine overall changes of gut microbiota. The intestinal barrier function will be measured using fluorescein isothiocyanate (FITC)-labeled dextran. Gut structure will also be analyzed by histological and immunohitochemical analysis. The phosphorylation of AMPK and related signaling pathways associated with epithelial renewal and differentiation will be further assessed. We expect that obesity will result in impaired epithelial cell differentiation and migration, and defective gut barrier function, which will be mitigated by dietary pigmented potatoes supplementation. In addition, we expect that CGA and anthocyanins in pigmented potato act together to activate AMPK and exert beneficial effects on epithelial health.Aim 2. Examine the mediatory role of AMPK in linking potato polyphenols to gut epithelial development and integrity. We will use epithelial cell cultures and AMPK conditional knockout mice to test the regulatory role of AMPK in linking potato polyphenols and gut epithelial health. Human colonic epithelial Caco-2 cells transfected with EGFP (CON), AMPK constant active (AMPKα WT) or AMPKα dominant negative constructs (K45R) will be treated with different amounts of Purple Pelisse polyphenol extract. The protein and mRNA level of intestinal epithelial differentiation markers and transcription factors and barrier functions will be analyzed. We expect that the promoting effects of polyphenols on epithelial differentiation will be blunted in AMPK deficient cells, demonstrating a mediatory role of AMPK. In addition, we plan to knockout AMPK specifically in intestinal epithelial cells using a double transgenic mice obtained by crossing AMPK floxed mice with Lgr5-Cre mice. Lgr5 is an exclusive marker of the intestinal epithelial stem cells. We expect that purple potato is effective in improving gut health in AMPK normal mice, but not in AMPK KO mice, showing the necessity of AMPK in mediating the beneficial effects of potato.

Progress 03/01/20 to 02/28/21

Outputs
Target Audience:Scientific community and commodity groups Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three PhD students had been receiving training through this project. This project also provides training opportunities for a visiting professor and one undergraduate student. How have the results been disseminated to communities of interest?Peer-reviewed publications, meeting abstracts and presentations. What do you plan to do during the next reporting period to accomplish the goals?We will be continuing our research efforts on studying the beneficial effects of purple potatoes on gut health and exploring underlying mechanisms.

Impacts
What was accomplished under these goals? Perturbation of gut epithelial barrier function is a central pathogenic factor for gut inflammation and associated disorders, which are becoming common due to intake of western high fat diet and the prevalence of obesity. Purple potatoes contain a high level of beneficial polyphenolic compounds, which are hypothesized to have anti-obesity effects through improving gut barrier function, suppressing inflammation, and preventing dysbiosis. We previously reported that polyphenol-rich purple potato extract enhances intestinal epithelial differentiation and improves gut barrier function, which reduces gut inflammation associated with a high-fat diet. We further found that AMP-activated protein kinase has a mediatory role. In mice, dietary purple potatoes ameliorated inflammation and symptoms of colitis in interleukin-10-deficient mice associated with the improved gut structure and goblet cell abundance. Gut microbiota is recognized as a crucial factor contributing to inflammatory intestinal disease. Associated with improved gut epithelial health, dietary purple potato supplementation restored gut microbiota dysbiosis in interleukin-10-deficient mice. Specifically, purple potato supplementation increased Firmicutes, a predominant phylum in gut microbiota, and bloomed Bifidobacteriaceae, Porphyromonadaceae, and Lachnospiraceae-Ruminococcaceae family, both of which are decreased in individuals with intestinal inflammatory disease and colitis. Metabolic dysregulation has been increasingly implicated in the incidence of intestinal inflammatory disease. Intestinal epithelial cells have a very high metabolic rate and control the anaerobic state of the intestinal lumen, which in turn contributes to microbial homeostasis and dysbiosis. Alpha-ketoglutarate, as an intermediate of the Krebs cycle, is a significant source of energy for epithelial cells of the gastrointestinal tract. We found that alpha-KG supplementation suppressed inflammation and the Wnt signaling pathway, improved epithelial structure, and enhanced M1 to M2 macrophage polarization, which was associated with strengthened intestinal barrier function and enhanced glycolytic to oxidative metabolic transition.

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Tian, Q., A. Bravo-Iniguez, Q. Sun, H. Wang, M. Du and M. J. Zhu. 2021. Dietary alpha-ketoglutarate suppressed dextran sulfate sodium induced colitis associated glycolytic metabolism. Molecular Nutrition and Food Research. https://doi.org/10.1002/mnfr.202000936
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Bravo Iniguez, A., and M. J. Zhu. 2020. Hop bioactive compounds in prevention of nutrition-related noncommunicable diseases. Critical Reviews in Food Science and Nutrition, https://doi.org/10.1080/10408398.2020.1767537
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Tian, Q., Z. Xu, X. Sun, J. Deavila, M. Du, and M. J. Zhu. 2020. Grape pomace inhibits colon carcinogenesis by suppressing cell proliferation and inducing epigenetic modifications. Journal of Nutritional Biochemistry, 84:108443.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2021 Citation: Bibi, S., Y. Xue, Y. He, M. Du, B. Chew, D. A. Navarre, and M. J. Zhu. 2021. Dietary purple potato supplementation ameliorates gut inflammation and associated colitis. American Nutrition Society Annual Meeting, Virtual, June 7-10, 2021.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2021 Citation: Sun, Q., D. A. Navarre, M. Du, and M. J. Zhu. 2021. Cooking methods on extractability and bioactivity of polyphenolic compounds in purple potatoes. American Nutrition Society Annual Meeting, Virtual, June 7-10, 2021.
  • Type: Conference Papers and Presentations Status: Submitted Year Published: 2021 Citation: Wang, H., Q. Tian, Z. Xu, A. B. Iniguez, M. Du, and M. J. Zhu. 2021. Metabolomic profiling for the preventive effects of dietary grape pomace against colorectal cancer. American Nutrition Society Annual Meeting, Virtual, June 7-10, 2021.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Tian, Q., Z. Xu, X. Sun, J. Deavila, M. Du, and M. J. Zhu. 2020. Grape pomace inhibits colon carcinogenesis by suppressing cell proliferation and inducing epigenetic modifications in an AOM/DSS mouse model. American Nutrition Society Annual Meeting, Seattle, Washington, June 1-4, 2020.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Tian, Q., M. Du, Z. Xu, and M. J. Zhu. 2020. Sulforaphane protects against DSS-induced acute colitis. American Nutrition Society Annual Meeting, Seattle, Washington, June 1-4, 2020.


Progress 03/01/19 to 02/29/20

Outputs
Target Audience:Scientific community and commodity groups Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two PhD students had been receiving training through this project. This project also provides training opportunities for a postdoc research associate and one undergraduate student. How have the results been disseminated to communities of interest?Peer-reviewed publications, meeting abstracts and presentations. What do you plan to do during the next reporting period to accomplish the goals?We will be continuing our research efforts on studying the beneficial effects of purple potatoes on gut health and exploring underlying mechanisms.

Impacts
What was accomplished under these goals? Perturbation of gut epithelial barrier function is a central pathogenic factor for gut inflammation and associated disorders, which are becoming common due to intake of western high fat diet and the prevalence of obesity. Purple potatoes contain a high level of beneficial polyphenolic compounds, which are hypothesized to have anti-obesity effects through improving gut barrier function, suppressing inflammation and preventing dysbiosis. We previously reported that polyphenol-rich purple potato extract enhances intestinal epithelial differentiation and improves gut barrier function, which reduces gut inflammation associated with high fat diet and further explored the regulatory roles of AMP-activated protein kinase. During the last period, we further studied the beneficial effects of dietary purple potatoes on gut health in vivo. Our studies showed that dietary purple potatoes ameliorated the inflammation and symptom of colitis in interleukin-10-deficient mice associated with improved gut structure and goblet cells. The analyses of gut samples and gut microbiota are ongoing. Additionally, we studied the protective effects of quercetin, a closely related polyphenol widely found in vegetables and fruits, against colonization of pathogenic bacteria in gut epithelium, a major cause of gut inflammation and associated diseases, which showed that polyphenol is beneficial against pathogenic bacteria in the gut inhabitation via interfering integrin β1 and focal adhesion kinase association.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Bibi, S., D. A. Navarre, X. Sun, M. Du, D. B. Rasco, and M. J. Zhu. 2019. Effect of potato consumption on gut microbiome and intestinal epithelial health. American Journal of Potato Research, 2019: 1-7.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: L.F. de Sousa Moraes, X. Sun, M. C. G. Peluzio, and M. J. Zhu. 2019. Anthocyanins /anthocyanidins and colorectal cancer: what is behind the scenes? Critical Reviews in Food Science and Nutrition, 59: 59-71
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wang, H., S. Zhang, Q. Shen, and M. J. Zhu. 2019. A metabolome explanation on beneficial effects of dietary Goji on intestine inflammation. Journal of Functional Food, 53: 109-114.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Zhu, M. J., X. Sun, and M. Du. 2019. AMPK ablation aggravates colorectal tumorigenesis via epigenetic suppression of antioncogenes. Experimental Biology Meeting, Orlando, Florida, April 6-9, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Wang, H., S. Zhang, and M. J. Zhu. 2019. Fecal metabolomic response of IL-10-deficient mice supplemented with Goji. Experimental Biology Meeting, Orlando, Florida, April 6-9, 2019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Xue, Y., M. Du, and M. J. Zhu*. 2019. Raspberry extract prevents Escherichia coli O157:H7-induced NLRP3 inflammasome activation. Journal of Functional Food, 56: 224-231.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Xue, Y., M. Du, and M. J. Zhu. 2019. Escherichia coli O157:H7 attaches to epithelial cells by stabilizing focal adhesions, a process suppressed by quercetin. Frontier Microbiology, 9: 3278.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Zhang, S, Wang, H., and M. J. Zhu. 2019. A sensitive GC/MS detection method for analyzing microbial metabolites short chain fatty acids in fecal and serum samples. Talanta,196: 249-254.


Progress 03/01/18 to 02/28/19

Outputs
Target Audience:Scientific community and commodity groups Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two PhD students had been receiving training through this project. This project also provides training opportunities for a postdoc research associate and one undergraduate student. How have the results been disseminated to communities of interest?Peer-reviewed publications, meeting abstracts and presentations. What do you plan to do during the next reporting period to accomplish the goals?We will be continuing our research efforts on studying the beneficial effects of purple potato on gut health and exploring underlying mechanisms.

Impacts
What was accomplished under these goals? Proper intestinal barrier is essential for health, which is maintained by a delicate balance of epithelial proliferation and differentiation. Perturbation of gut epithelial barrier function induces inflammation and other health problems that originated from the gut. Purple potato contains a high level of beneficial polyphenolic compounds. During the past year, we have been conducting studies on the beneficial effects of polyphenol extracted from purple potato on intestinal barrier function and explore its underlying mechanism. We found that purple potato extract (PPE) increased transepithelial electrical resistance and decreased FITC-dextran paracellular flux in epithelial cells, which were associated with strengthened intestinal epithelial differentiation in intestinal epithelial cells and ex vivo cultured gut. Furthermore, PPE treatment enhanced AMP-activated protein kinase (AMPK) activity, concomitant with the increased expression of CDX2, a key transcriptional factor regulating intestinal epithelial differentiation. Knocking out AMPK using CRISPR/Cas9 system abolished the positive effects of PPE on intestinal epithelial differentiation and barrier function, in junction with the reduced expression of CDX2. Data collectively indicated that PPE improved gut epithelial differentiation and barrier function via activating AMPK. Butyrate, a gut microbial metabolite, is known for its beneficial effects for intestinal epithelial health. We found that butyrate suppresses proliferation, potentiates differentiation and induces apoptosis in human colonic epithelial cells via enhancing α-ketoglutarate-dependent DNA demethylation of mismatch repair genes. Data points to a close link among dietary polyphenols, gut microbial metabolites, and epigenetic modifications associated with intestinal health.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zhu, M. J., and M. Du. 2018. Purple potato polyphenols target AMPK to improve gut epithelial health. 2018 Innovations in Food Science and Human Nutrition. Rome, Italy, September 13-15th, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zhu, M. J. 2018. Polyphenols and associated AMPK activation in management of inflammatory bowel disease. 2018 World Gastroenterology & Hepatology Conference, Rome, Italy, September 10-12th, 2018.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Sun, X., M. Du, D. A. Navarre and M. J. Zhu. 2018. Purple potato extract promotes intestinal epithelial differentiation and barrier function by activating AMP-activated protein kinase. Molecular Nutrition and Food Research, 62:1700536.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Sun, X., X. Fu, M. Du, and M. J. Zhu. 2018. Ex vivo gut culture for tracing gut epithelial development. Open Biology, 8: 170256.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Sun, X., and M. J. Zhu. 2018. Butyrate inhibits indices of colorectal carcinogenesis via enhancing ?-ketoglutarate-dependent DNA demethylation of mismatch repair genes. Molecular Nutrition Food Research, 62: 1700932.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Kang, Y., Y. Guan, S. Zhang, C. Ross, M. J. Zhu. 2018. Goji berry modulates gut microbiota and alleviates colitis in IL-10-deficient mice. Molecular Nutrition Food Research, 62: 1800535
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Zhu, M. J., X. Sun, X. Fu, and M. Du. 2018. AMPK in regulation of apical junctions and barrier function of intestinal epithelium. Tissue Barriers, 6: 1-13.
  • Type: Book Chapters Status: Published Year Published: 2018 Citation: Zhu, M. J. 2018. Dietary polyphenols, gut microbiota and intestinal epithelial health. In Nutritional and Therapeutic Interventions for Diabetes and Metabolic Syndromes. Page 295-314. Edited by Debasis Bagchi and Sreejayan Nair. 2nd eds. CRC press, Talyor & Francis.