title: Fatty acid ethyl esters induce intestinal epithelial barrier dysfunction via a reactive oxygen species-dependent mechanism in a three-dimensional cell culture model.
abstract: OBJECTIVE
  Evidence is accumulating that ethanol and its oxidative metabolite, acetaldehyde, can disrupt intestinal epithelial integrity, an important factor contributing to ethanol-induced liver injury. However, ethanol can also be metabolized non-oxidatively generating phosphatidylethanol and fatty acid ethyl esters (FAEEs). This study aims to investigate the effects of FAEEs on barrier function, and to explore the role of oxidative stress as possible mechanism.
  
  
  METHODS
  Epithelial permeability was assessed by paracellular flux of fluorescein isothiocyanate-conjugated dextran using live cell imaging. Cell integrity was evaluated by lactate dehydrogenase release. Localization and protein levels of ZO-1 and occludin were analyzed by immunofluorescence and cell-based ELISA, respectively. Intracellular oxidative stress and cellular ATP levels were measured by dichlorofluorescein and luciferase driven bioluminescence, respectively.
  
  
  RESULTS
  In vitro, ethyl oleate and ethyl palmitate dose dependently increased permeability associated with disruption and decreased ZO-1 and occludin protein levels, respectively, and increased intracellular oxidative stress without compromising cell viability. These effects could partially be attenuated by pretreatment with the antioxidant, resveratrol, pointing to the role of oxidative stress in the FAEEs-induced intestinal barrier dysfunction.
  
  
  CONCLUSIONS
  These findings show that FAEEs can induce intestinal barrier dysfunction by disrupting the tight junctions, most likely via reactive oxygen species-dependent mechanism.
authors.affiliation: Top Institute Food and Nutrition TIFN, Wageningen, The Netherlands.
authors.forename: Elhaseen
authors.initials: E
authors.lastname: Elamin
authors.forename: Ad
authors.initials: A
authors.lastname: Masclee
authors.forename: Kati
authors.initials: K
authors.lastname: Juuti-Uusitalo
authors.forename: Sven
authors.initials: S
authors.lastname: van Ijzendoorn
authors.forename: Freddy
authors.initials: F
authors.lastname: Troost
authors.forename: Harm-Jan
authors.initials: HJ
authors.lastname: Pieters
authors.forename: Jan
authors.initials: J
authors.lastname: Dekker
authors.forename: Daisy
authors.initials: D
authors.lastname: Jonkers
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D018938:Caco-2 Cells; D018929:Cell Culture Techniques; D002463:Cell Membrane Permeability / Q000187:drug effects; D000431:Ethanol / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000503:physiopathology*; D008954:Models, Biological; D062793:Occludin / Q000378:metabolism; D009829:Oleic Acids / Q000378:metabolism / Q000633:toxicity*; D018384:Oxidative Stress; D010169:Palmitic Acids / Q000378:metabolism / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: C568985:OCLN protein, human; D062793:Occludin; D009829:Oleic Acids; D010169:Palmitic Acids; D017382:Reactive Oxygen Species; D013267:Stilbenes; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D000431:Ethanol; D000255:Adenosine Triphosphate; C007680:ethyl palmitate; D000077185:Resveratrol; C033180:ethyl oleate