title: Lactobacillus plantarum ameliorates colonic epithelial barrier dysfunction by modulating the apical junctional complex and PepT1 in IL-10 knockout mice.
abstract: Probiotics are efficacious in the treatment of inflammatory bowel disease. However, the precise mechanisms remain unknown. To determine whether probiotic Lactobacillus plantarum (LP) ameliorates colonic epithelial barrier dysfunction present in interleukin-10 knockout (IL-10⁻(/)⁻) mice, IL-10⁻(/)⁻ and wild-type mice received LP or the vehicle for 4 wk. Colitis was assessed by histological scores and clinical manifestation, and gut paracellular permeability was measured by Ussing chamber. Oligopeptide transporter 1 (PepT1)-mediated transepithelial transport was evaluated by measuring the plasma cephalexin concentration. The expression and distribution of apical junctional complex (AJC) proteins and PepT1 were determined by Western blotting and immunofluorescence and their mRNA by reverse transcriptase-PCR. Spontaneous colitis was observed in all IL-10⁻(/)⁻ mice in which paracellular permeability was increased, in conjunction with decreased expression and redistribution of zonula occludens-1, occludin, claudin-1, and β-catenin. PepT1 expression was increased, accompanied with an enhanced cephalexin transport. Colonic epithelial barrier dysfunction was further confirmed by increased bacterial translocation and proinflammatory cytokine production. Treatment with LP decreased colonic paracellular permeability with restoration of expression and distribution of AJC proteins and partially prevented PepT1 expression and cephalexin transport in IL-10⁻(/)⁻ mice. Moreover, treatment with LP also prevented bacterial translocation and proinflammatory cytokine production in IL-10⁻(/)⁻ mice. Results from this study indicated that treatment with LP may ameliorate colonic epithelial barrier dysfunction in IL-10⁻(/)⁻ mice, by modulating the AJC- and PepT1-mediated transepithelial transport.
authors.affiliation: Dept. of General Surgery, Affiliated Sixth People's Hospital, Shanghai Jiao Tong Univ., People's Republic of China.
authors.forename: Hong-Qi
authors.initials: HQ
authors.lastname: Chen
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Yu-Kun
authors.initials: YK
authors.lastname: Zhou
authors.forename: Tong-Yi
authors.initials: TY
authors.lastname: Shen
authors.forename: Zhao-Xin
authors.initials: ZX
authors.lastname: Chu
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Hang
authors.forename: Yan-Qun
authors.initials: YQ
authors.lastname: Jiang
authors.forename: Huan-Long
authors.initials: HL
authors.lastname: Qin
mesh_terms: D000818:Animals; D001692:Biological Transport; D003092:Colitis / Q000517:prevention & control; D003106:Colon / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology; D007249:Inflammation / Q000378:metabolism; D016753:Interleukin-10 / Q000235:genetics* / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000503:physiopathology*; D048191:Lactiplantibacillus plantarum; D051379:Mice; D018345:Mice, Knockout; D000074011:Peptide Transporter 1; D027981:Symporters / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000074011:Peptide Transporter 1; C489941:Slc15a1 protein, mouse; D027981:Symporters; D016753:Interleukin-10