Bock, Juergen and Liebisch, Gerhard and Schweimer, Joachim and Schmitz, Gerd and Rogler, Gerhard (2007) Exogenous sphingomyelinase causes impaired intestinal epithelial barrier function. WORLD JOURNAL OF GASTROENTEROLOGY, 13 (39). pp. 5217-5225. ISSN 1007-9327,
Full text not available from this repository. (Request a copy)Abstract
AIM: To test the hypothesis that hydrolysis of sphingomyelin to ceramide changes the composition of tight junctions (TJs) with increasing permeability of the intestinal epithelium. METHODS: Monolayers of Caco-2 cells were used as an in vitro model for the intestinal barrier. Permeability was determined by quantification of transepithelial flux and transepithelial resistance. Sphingolipid-rich membrane microdomains were isolated by a discontinuous sucrose gradient and characterized by Western-blot. Lipid content of microdomains was analysed by tandem mass spectrometry. Ceramide was subcellularly localized by immunofluorescent staining. RESULTS: Exogenous sphingomyelinase increased transepithelial permeability and decreased transepithelial resistance at concentrations as low as 0.01 U/mL. Lipid analysis showed rapid accumulation of ceramide in the membrane fractions containing occludin and claudin-4, representing TJs. In these fractions we observed a concomitant decrease of sphingomyelin and cholesterol with increasing concentrations of ceramide. Immunofluorescent staining confirmed clustering of ceramide at the sites of cell-cell contacts. Neutralization of surface ceramide prevented the permeability-increase induced by platelet activating factor. CONCLUSION: Our findings indicate that changes in lipid composition of TJs impair epithelial barrier functions. Generation of ceramide by sphingomyelinases might contribute to disturbed barrier function seen in diseases such as inflammatory, infectious, toxic or radiogenic bowel disease. (C) 2007 WJG. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | TANDEM MASS-SPECTROMETRY; RICH MEMBRANE RAFTS; HIGH-THROUGHPUT QUANTIFICATION; ACID SPHINGOMYELINASE; CROHNS-DISEASE; CERAMIDE; APOPTOSIS; CELLS; PHOSPHATIDYLCHOLINE; CYTOKINES; ceramide; cholesterol; tight-junction; Caco-2 cells; permeability; inflammatory bowel disease |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Innere Medizin I Medicine > Lehrstuhl für Klinische Chemie und Laboratoriumsmedizin |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Dec 2020 07:05 |
| Last Modified: | 02 Dec 2020 07:05 |
| URI: | https://pred.uni-regensburg.de/id/eprint/32065 |
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