title: Pectin from Prunus domestica L. induces proliferation of IEC-6 cells through the alteration of cell-surface heparan sulfate on differentiated Caco-2 cells in co-culture.
abstract: Dietary fiber intake provides various physiological and metabolic effects for human health. Pectin, a water-soluble dietary fiber, induces morphological changes of the small intestine in vivo. However, the molecular mechanisms underlying pectin-derived morphological alterations have not been elucidated. Previously, we found that pectin purified from Prunus domestica L. altered the sulfated structure of cell-surface heparan sulfate (HS) on differentiated Caco-2 cells via fibronectin and α5β1 integrin. In this study, we investigated the biological significance of the effect of pectin on HS in differentiated Caco-2 cells. An in vitro intestinal epithelium model was constructed by co-culture of differentiated Caco-2 cells and rat IEC-6 cells, which were used as models of intestinal epithelium and intestinal crypt cells, respectively. We found that pectin-treated differentiated Caco-2 cells promoted growth of IEC-6 cells. Real-time RT-PCR analysis and western blotting showed that relative mRNA and protein expression levels of Wnt3a were upregulated by pectin treatment in differentiated Caco-2 cells. Analysis by surface plasmon resonance spectroscopy demonstrated that pectin-induced structural alteration of HS markedly decreased the interaction with Wnt3a. However, depression in the secretion of Wnt3a from Caco-2 cells by anti-Wnt3a antibody did not affect the proliferation of IEC-6 cells in co-culture system. These observations indicated that pectin altered the sulfated structure of cell-surface HS to promote secretion of Wnt3a from differentiated Caco-2 cells and Wnt3a indirectly stimulated the proliferation of IEC-6 cells.
authors.affiliation: United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Nishida
authors.forename: Kazuma
authors.initials: K
authors.lastname: Murata
authors.forename: Kazuya
authors.initials: K
authors.lastname: Oshima
authors.forename: Chihiro
authors.initials: C
authors.lastname: Itoh
authors.forename: Kohji
authors.initials: K
authors.lastname: Kitaguchi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kanamaru
authors.forename: Tomio
authors.initials: T
authors.lastname: Yabe
mesh_terms: D000818:Animals; D018938:Caco-2 Cells / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006497:Heparan Sulfate / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism; D010368:Pectins / Q000494:pharmacology*; D000068242:Prunus domestica / Q000737:chemistry*; D051381:Rats; D020349:Surface Plasmon Resonance; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism; D060509:Wnt3A Protein / Q000378:metabolism
chemical_list: D006497:Heparan Sulfate; D010368:Pectins; D051153:Wnt Proteins; D060509:Wnt3A Protein; C555510:WNT3A protein, human