title: Probiotic-derived polyphosphate enhances the epithelial barrier function and maintains intestinal homeostasis through integrin-p38 MAPK pathway.
abstract: Probiotics exhibit beneficial effects on human health, particularly in the maintenance of intestinal homeostasis in a complex manner notwithstanding the diversity of an intestinal flora between individuals. Thus, it is highly probable that some common molecules secreted by probiotic and/or commensal bacteria contribute to the maintenance of intestinal homeostasis and protect the intestinal epithelium from injurious stimuli. To address this question, we aimed to isolate the cytoprotective compound from a lactobacillus strain, Lactobacillus brevis SBC8803 which possess the ability to induce cytoprotective heat shock proteins in mouse small intestine. L. brevis was incubated in MRS broth and the supernatant was passed through with a 0.2-µm filter. Caco2/bbe cells were treated with the culture supernatant, and HSP27 expression was evaluated by Western blotting. HSP27-inducible components were separated by ammonium sulfate precipitation, DEAE anion exchange chromatography, gel filtration, and HPLC. Finally, we identified that the HSP27-inducible fraction was polyphosphate (poly P), a simple repeated structure of phosphates, which is a common product of lactobacilli and other bacteria associated with intestinal microflora without any definitive physiological functions. Then, poly P was synthesized by poly P-synthesizing enzyme polyphosphate kinase. The synthesized poly P significantly induced HSP27 from Caco2/BBE cells. In addition, Poly P suppressed the oxidant-induced intestinal permeability in the mouse small intestine and pharmacological inhibitors of p38 MAPK and integrins counteract its protective effect. Daily intrarectal administration of poly P (10 µg) improved the inflammation grade and survival rate in 4% sodium dextran sulfate-administered mice. This study, for the first time, demonstrated that poly P is the molecule responsible for maintaining intestinal barrier actions which are mediated through the intestinal integrin β1-p38 MAPK.
authors.affiliation: Frontier Laboratories of Value Creation, Sapporo Breweries Ltd., Yaizu, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Segawa
authors.forename: Mikihiro
authors.initials: M
authors.lastname: Fujiya
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Konishi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ueno
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Shigyo
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kohgo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018938:Caco-2 Cells; D003092:Colitis / Q000378:metabolism / Q000517:prevention & control; D003106:Colon / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression / Q000187:drug effects; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D019012:Integrin beta1 / Q000378:metabolism; D016023:Integrins / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects; D052196:Levilactobacillus brevis / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010539:Permeability / Q000187:drug effects; D011122:Polyphosphates / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D019936:Probiotics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D055551:HSP27 Heat-Shock Proteins; D019012:Integrin beta1; D016023:Integrins; D011122:Polyphosphates; D048051:p38 Mitogen-Activated Protein Kinases