title: Characterization of in vitro effects of patulin on intestinal epithelial and immune cells.
abstract: The intestinal mucosa is the first biological barrier encountered by natural toxins, and could possibly be exposed to high amounts of dietary mycotoxins. Patulin (PAT), a mycotoxin produced by Penicillium spp. during fruit spoilage, is one of the best known enteropathogenic mycotoxins able to alter functions of the intestine (Maresca et al., 2008). This study evaluated the effects of PAT on barrier function of the gut mucosa utilizing the intestinal epithelial cell model Caco-2, and scrutinized immunomodulatory effects using human peripheral blood mononuclear cells (PBMC) and human blood monocyte-derived dendritic cells (moDCs) as test systems. PAT exposure reduced Caco-2 cell viability at concentrations above 12μM. As expected, the integrity of a polarized Caco-2 monolayer was affected by PAT exposure, as demonstrated by a decrease in TER values, becoming more pronounced at 50μM. No effects were detected on the expression levels of the tight junction proteins occludin, claudin-1 and claudin-3 at 50μM. However, the expression of zonula occludens-1 (ZO-1) and myosin light chain 2 (MLC2) declined. Also, levels of phospho-MLC2 (p-MLC2) increased after 24h of exposure to 50μM of PAT. T cell proliferation was highly sensitive to PAT with major effects for concentrations above 10nM of PAT. The same conditions did not affect the maturation of moDC. PAT causes a reduction in Caco-2 barrier function mainly by perturbation of ZO-1 levels and the phosphorylation of MLC. Low doses of PAT strongly inhibited T cell proliferation induced by a polyclonal activator, but had no effect on the maturation of moDC. These results provide new information that strengthens the concept that the epithelium and immune cells of the intestinal mucosa are important targets for the toxic effects of food contaminants like mycotoxins.
authors.affiliation: Food and Nutrition Department, National Institute of Health Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal; IIFA, Universidade de Évora, Palácio do Vimioso, Largo Marquês de Marialva, Apartado 94, 7002-554 Évora, Portugal; Centre for Environmental and Marine Studies, CESAM, University of Aveiro, Aveiro, Portugal. Electronic address: ricardo.assuncao@insa.min-saude.pt.
authors.forename: R
authors.initials: R
authors.lastname: Assunção
authors.affiliation: Food and Nutrition Department, National Institute of Health Dr. Ricardo Jorge, Av. Padre Cruz, 1649-016 Lisboa, Portugal; Centre for Environmental and Marine Studies, CESAM, University of Aveiro, Aveiro, Portugal. Electronic address: paula.alvito@insa.min-saude.pt.
authors.forename: P
authors.initials: P
authors.lastname: Alvito
authors.affiliation: Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Post Box 5003, NO-1430 Aas, Norway. Electronic address: charlotte.kleiveland@nmbu.no.
authors.forename: C R
authors.initials: CR
authors.lastname: Kleiveland
authors.affiliation: Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Post Box 5003, NO-1430 Aas, Norway. Electronic address: tor.lea@nmbu.no.
authors.forename: T E
authors.initials: TE
authors.lastname: Lea
mesh_terms: D018938:Caco-2 Cells; D024722:Cardiac Myosins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D005516:Food Microbiology; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects*; D018994:Myosin Light Chains / Q000378:metabolism; D010365:Patulin / Q000378:metabolism / Q000633:toxicity*; D010407:Penicillium / Q000378:metabolism; D010539:Permeability; D010766:Phosphorylation; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D013997:Time Factors; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D018994:Myosin Light Chains; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; C107184:myosin light chain 2; D010365:Patulin; D024722:Cardiac Myosins
keywords: Immune effects; Intestinal mucosa; Patulin; Phosphorylation; Tight junctions