title: Antisecretory factor peptide AF-16 inhibits the secreted autotransporter toxin-stimulated transcellular and paracellular passages of fluid in cultured human enterocyte-like cells.
abstract: Both the endogenous antisecretory factor (AF) protein and peptide AF-16, which has a sequence that matches that of the active N-terminal region of AF, inhibit the increase in the epithelial transport of fluid and electrolytes induced by bacterial toxins in animal and ex vivo models. We conducted a study to investigate the inhibitory effect of peptide AF-16 against the increase of transcellular passage and paracellular permeability promoted by the secreted autotransporter toxin (Sat) in a cultured cellular model of the human intestinal epithelial barrier. Peptide AF-16 produced a concentration-dependent inhibition of the Sat-induced increase in the formation of fluid domes, in the mucosal-to-serosal passage of D-[1-(14)C]mannitol, and in the rearrangements in the distribution and protein expression of the tight junction (TJ)-associated proteins ZO-1 and occludin in cultured human enterocyte-like Caco-2/TC7 cell monolayers. In addition, we show that peptide AF-16 also inhibits the cholera toxin-induced increase of transcellular passage and the Clostridium difficile toxin-induced effects on paracellular permeability and TJ protein organization in Caco-2/TC7 cell monolayers. Treatment of cell monolayers by the lipid raft disorganizer methyl-β-cyclodextrin abolished the inhibitory activity of peptide AF-16 at the transcellular passage level and did not modify the effect of the peptide at the paracellular level.
authors.affiliation: IFR 141 IPSIT, Plateforme Imagerie Cellulaire, Faculté de Pharmacie, Châtenay-Malabry, France Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Nicolas
authors.affiliation: CNRS, UMR 8076 BioCIS, Faculté de Pharmacie, Châtenay-Malabry, France LabEx LERMIT-Laboratory of Excellence in Research on Medication and Innovative Therapeutics, Châtenay-Malabry, France Université Paris-Sud, Faculté de Pharmacie, Châtenay-Malabry, France vanessa.lievin-le-moal@u-psud.fr.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Liévin-Le Moal
mesh_terms: D000595:Amino Acid Sequence; D001692:Biological Transport / Q000187:drug effects; D018938:Caco-2 Cells; D002250:Carbon Radioisotopes; D002772:Cholera Toxin / Q000037:antagonists & inhibitors* / Q000633:toxicity; D020895:Enterocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004768:Enterotoxins / Q000037:antagonists & inhibitors* / Q000633:toxicity; D006801:Humans; D007700:Kinetics; D008353:Mannitol / Q000378:metabolism; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010539:Permeability / Q000187:drug effects; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: D002250:Carbon Radioisotopes; D004768:Enterotoxins; D009479:Neuropeptides; D010455:Peptides; C049628:antisecretory factor; D047392:beta-Cyclodextrins; C035598:enterotoxin, Clostridium; C108732:methyl-beta-cyclodextrin; C533586:peptide AF-16; D008353:Mannitol; D002772:Cholera Toxin