title: Sieving characteristics of cytokine- and peroxide-induced epithelial barrier leak: Inhibition by berberine.
abstract: OBJECTIVE
  To study whether the inflammatory bowel disease (IBD) colon which exhibits varying severity and cytokine levels across its mucosa create varying types of transepithelial leak.
  
  
  METHODS
  We examined the effects of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1-β (IL1β) and hydrogen peroxide (H2O2) - singly and in combinations - on barrier function of CACO-2 cell layers. Our focus was on the type (not simply the magnitude) of transepithelial leak generated by these agents as measured by transepithelial electrical resistance (TER) and transepithelial flux of (14)C-D-mannitol, (3)H-Lactulose and (14)C-Polyethylene glycol as radiolabeled probe molecules. The isoquinoline alkaloid, berberine, was then examined for its ability to reduce specific types of transepithelial leak.
  
  
  RESULTS
  Exposure to TNF-α alone (200 ng/mL; 48 h) induced a 50% decrease in TER, i.e., increased leak of Na(+) and Cl(-) - with only a marginal but statistically significant increase in transepithelial leak of (14)C-mannitol (Jm). Exposure to TNF-α + IFN-γ (200 ng/mL; 48 h) + IL1β (50 ng/mL; 48 h) did not increase the TER change (from TNF-α alone), but there was now a 100% increase in Jm. There however was no increase in transepithelial leak of two larger probe molecules, (3)H-lactulose and (14)C-polyethylene glycol (PEG). However, exposure to TNF-α + IFN-γ + IL1β followed by a 5 h exposure to 2 mmol/L H2O2 resulted in a 500% increase in (14)C-PEG leak as well as leak to the luminal mitogen, epidermal growth factor.
  
  
  CONCLUSIONS
  This model of graded transepithelial leak is useful in evaluating therapeutic agents reducing IBD morbidity by reducing barrier leak to various luminal substances.
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: DiGuilio
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Mercogliano
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Jillian
authors.initials: J
authors.lastname: Born
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Brendan
authors.initials: B
authors.lastname: Ferraro
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Julie
authors.initials: J
authors.lastname: To
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Brittany
authors.initials: B
authors.lastname: Mixson
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Allison
authors.initials: A
authors.lastname: Smith
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: Mary Carmen
authors.initials: MC
authors.lastname: Valenzano
authors.affiliation: Katherine M DiGuilio, Christina M Mercogliano, Brittany Mixson, Allison Smith, Mary Carmen Valenzano, James M Mullin, Lankenau Institute for Medical Research, Lankenau Medical Center, Wynnewood, PA 19096, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Mullin
keywords: Berberine; CACO-2; Crohn’s disease; Cytokine; Intestine; Micronutrient; Tight junction; Ulcerative colitis