HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (31) Citing Articles via Google Scholar Google Scholar Articles by Ye, D. Articles by Ma, T. Y. Search for Related Content PubMed PubMed Citation Articles by Ye, D. Articles by Ma, T. Y.

INFLAMMATION/IMMUNITY/MEDIATORS

Molecular mechanism of tumor necrosis factor- modulation of intestinal epithelial tight junction barrier

Department of Internal Medicine, University of New Mexico School of Medicine and Albuquerque Veterans Affairs Medical Center, Albuquerque, New Mexico

Submitted 10 July 2005 ; accepted in final form 19 September 2005

A TNF--induced increase in intestinal epithelial tight junction (TJ) permeability has been proposed to be an important proinflammatory mechanism contributing to intestinal inflammation in Crohn's disease and other inflammatory conditions. Previous studies from our laboratory suggested that the TNF--induced increase in intestinal TJ permeability was mediated by an increase in myosin light chain kinase (MLCK) protein expression. However, the molecular mechanisms that mediate the TNF- increase in intestinal TJ permeability and MLCK protein expression remain unknown. The purpose of this study was to delineate the intracellular and molecular mechanisms that mediate the TNF--induced increase in intestinal TJ permeability; using an in vitro intestinal epithelial model system consisting of filter-grown Caco-2 intestinal epithelial monolayers. To examine the molecular mechanisms involved in the TNF- regulation of intestinal TJ barrier, we identified and cloned for the first time a functionally active MLCK promoter region. TNF- treatment of filter-grown Caco-2 monolayers transfected with plasmid vector containing the MLCK promoter region produced an increase in MLCK promoter activity and MLCK transcription. The TNF--induced increase in MLCK transcription corresponded to a sequential increase in MLCK protein expression, MLCK activity, and Caco-2 TJ permeability. The TNF--induced increase in MLCK promoter activity was mediated by NF-B activation, and the inhibition of NF-B activation prevented the TNF--induced increase in promoter activity and the subsequent increase in MLCK protein expression and Caco-2 TJ permeability. The TNF--induced activation of MLCK promoter was mediated by binding of the activated NF-B p50/p65 dimer to the downstream B binding site (–84 to –75) on the MLCK promoter region; deletion of the B binding site prevented the TNF- increase in promoter activity. Additionally, siRNA silencing of NF-B p65 also prevented the TNF- increase in MLCK promoter activity. In conclusion, our findings indicated that the TNF--induced increase in intestinal epithelial TJ permeability was mediated by NF-B p50/p65 binding and activation of the MLCK promoter. NF-B p50/p65 activation of the MLCK promoter then leads to a stepwise increase in MLCK transcription, expression and activity, and MLCK-mediated opening of the intestinal TJ barrier.

Crohn's disease; intestinal permeability; myosin light chain kinase

This article has been cited by other articles:

				K. Kimura, S. Teranishi, and T. Nishida Interleukin-1{beta}-Induced Disruption of Barrier Function in Cultured Human Corneal Epithelial Cells Invest. Ophthalmol. Vis. Sci., February 1, 2009; 50(2): 597 - 603. [Abstract] [Full Text] [PDF]

				W. Fries, C. Muja, C. Crisafulli, S. Cuzzocrea, and E. Mazzon Dynamics of enterocyte tight junctions: effect of experimental colitis and two different anti-TNF strategies Am J Physiol Gastrointest Liver Physiol, April 1, 2008; 294(4): G938 - G947. [Abstract] [Full Text] [PDF]

				K. Lewis, J. Caldwell, V. Phan, D. Prescott, A. Nazli, A. Wang, J. D. Soderholm, M. H. Perdue, P. M. Sherman, and D. M. McKay Decreased epithelial barrier function evoked by exposure to metabolic stress and nonpathogenic E. coli is enhanced by TNF-{alpha} Am J Physiol Gastrointest Liver Physiol, March 1, 2008; 294(3): G669 - G678. [Abstract] [Full Text] [PDF]

				K. Kimura, S. Teranishi, K. Fukuda, K. Kawamoto, and T. Nishida Delayed Disruption of Barrier Function in Cultured Human Corneal Epithelial Cells Induced by Tumor Necrosis Factor-{alpha} in a Manner Dependent on NF-{kappa}B Invest. Ophthalmol. Vis. Sci., February 1, 2008; 49(2): 565 - 571. [Abstract] [Full Text] [PDF]

				S. Skrovanek, M. C. Valenzano, and J. M. Mullin Restriction of sulfur-containing amino acids alters claudin composition and improves tight junction barrier function Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1046 - R1055. [Abstract] [Full Text] [PDF]

				A. T. Blikslager, A. J. Moeser, J. L. Gookin, S. L. Jones, and J. Odle Restoration of Barrier Function in Injured Intestinal Mucosa Physiol Rev, April 1, 2007; 87(2): 545 - 564. [Abstract] [Full Text] [PDF]

				M. A. Boivin, D. Ye, J. C. Kennedy, R. Al-Sadi, C. Shepela, and T. Y. Ma Mechanism of glucocorticoid regulation of the intestinal tight junction barrier Am J Physiol Gastrointest Liver Physiol, February 1, 2007; 292(2): G590 - G598. [Abstract] [Full Text] [PDF]

				W. V. Graham, F. Wang, D. R. Clayburgh, J. X. Cheng, B. Yoon, Y. Wang, A. Lin, and J. R. Turner Tumor Necrosis Factor-induced Long Myosin Light Chain Kinase Transcription Is Regulated by Differentiation-dependent Signaling Events: CHARACTERIZATION OF THE HUMAN LONG MYOSIN LIGHT CHAIN KINASE PROMOTER J. Biol. Chem., September 8, 2006; 281(36): 26205 - 26215. [Abstract] [Full Text] [PDF]