title: Glutamine and arginine improve permeability and tight junction protein expression in methotrexate-treated Caco-2 cells.
abstract: OBJECTIVE
  Chemotherapy induces an increase of intestinal permeability that is partially related to an alteration of tight junction proteins, occludin and zonula occludens-1 (ZO-1). Protective effects of glutamine on intestinal barrier function have been previously shown but the effects of other amino acids remained poorly documented. Thus, we aimed to evaluate the effects of nine amino acids on intestinal permeability during methotrexate (MTX) treatment in Caco-2 cells.
  
  
  METHODS
  Caco-2 cells were incubated in culture medium supplemented with glutamine, arginine, glutamate, leucine, taurine, citrulline, glycine, histidine or cysteine during 24 h and then treated with MTX (100 ng/ml). The dose of each amino acid was 16.6 fold the physiological plasma concentrations. Barrier function was assessed by transepithelial electrical resistance (TEER), FITC-dextran paracellular flux, occludin and ZO-1 expression and localization. Signaling pathways were also studied.
  
  
  RESULTS
  Only glutamine, glutamate, arginine and leucine reversed the decrease of TEER observed after MTX treatment (P < 0.05). Interestingly, the addition of 6-diazo-5-oxo-1-norleucine, an inhibitor of glutaminase, blunted the effect of glutamine on MTX-treated cells (P < 0.05). Glutamine and arginine combination restored TEER and FITC-dextran flux to a similar extent than glutamine alone. In addition, pretreatment of Caco-2 cells with glutamine and arginine, alone or combined, differently limited the decrease of ZO-1 and occludin expression (P < 0.05) and the alteration of their cellular distribution, through c-Jun N-terminal kinase (JNK), Extracellular signal-regulated kinase (ERK) and nuclear factor kappa B (NF-κB) pathways.
  
  
  CONCLUSIONS
  Glutamine prevented MTX-induced barrier disruption in Caco-2 cells. Arginine also had protective effects but in a lesser extent. The effect of glutamine and arginine should be evaluated in vivo.
authors: INSERM Unit 1073, Rouen University, Rouen, France; Institute for Research and Innovation in Biomedicine, Rouen University, Rouen, France.
authors: Stéphanie
authors: S
authors: Beutheu
authors: Ibtissem
authors: I
authors: Ghouzali
authors: Ludovic
authors: L
authors: Galas
authors: Pierre
authors: P
authors: Déchelotte
authors: Moïse
authors: M
authors: Coëffier
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000737:chemistry; D001120:Arginine / Q000378:metabolism* / Q000627:therapeutic use; D018938:Caco-2 Cells; D019587:Dietary Supplements; D020895:Enterocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005493:Folic Acid Antagonists / Q000009:adverse effects / Q000737:chemistry; D005765:Gastrointestinal Agents / Q000378:metabolism / Q000627:therapeutic use; D005973:Glutamine / Q000378:metabolism* / Q000627:therapeutic use; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008727:Methotrexate / Q000009:adverse effects / Q000037:antagonists & inhibitors*; D052016:Mucositis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D019384:Nucleic Acid Synthesis Inhibitors / Q000009:adverse effects / Q000737:chemistry; D062793:Occludin / Q000096:biosynthesis* / Q000378:metabolism; D010539:Permeability / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015854:Up-Regulation / Q000187:drug effects; D062826:Zonula Occludens-1 Protein / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D005493:Folic Acid Antagonists; D005765:Gastrointestinal Agents; D019384:Nucleic Acid Synthesis Inhibitors; C568985:OCLN protein, human; D062793:Occludin; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D005973:Glutamine; D001120:Arginine; D008727:Methotrexate
keywords: 6-diazo-5-oxo-1-norleucine; Arg; Arginine; Chemotherapy; Cit; Cys; DON; ERK; Gln; Glu; Glutamine; Gut barrier; His; IκBα; JNK; Leu; MTX; NF-κB; Signaling pathways; TEER; TJ; Tau; ZO; Zonula occludens; arginine; c-Jun N-terminal kinase; citrulline; cysteine; extracellular signal-regulated kinase; glutamate; glutamine; gly; glycine; histidine; inhibitor of kappa B factor; leucine; methotrexate; nuclear factor kappa B; taurine; tight junctions; transepithelial resistance