Regulation of Toll-like receptor 4-associated MD-2 in intestinal epithelial cells: A comprehensive analysis

Arunan S. Vamadevan, Masayuki Fukata, Elizabeth T. Arnold, Lisa S. Thomas, David Hsu, Maria T Abreu

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

The intestinal epithelium maintains a state of controlled inflammation despite continuous contact with Gram-negative commensal bacteria and lipopolysaccharide (LPS) on its luminal surface. Recognition of LPS by the Toll-like receptor (TLR) 4/MD-2 complex results in pro-inflammatory gene expression and cytokine secretion in intestinal epithelial cells (IECs). We have shown that IECs express low levels of MD-2 and TLR4 and are poorly responsive to LPS. In this study, we did a comprehensive analysis to understand the immune-mediated and epigenetic mechanisms by which IECs down-regulate MD-2 expression. Expression of MD-2 and TLR4 mRNA was examined in human inflammatory bowel disease and intestinal epithelial cell lines (T84, HT-29, Caco-2). Nuclear factor-KB transcriptional activation was used as a measure of LPS responsiveness. Intestinal epithelial cells in patients with inflammatory bowel disease exhibited increased expression of MD-2 and TLR4 mRNA. Lipopolysaccharide responsiveness in IECs was polarized to the basolateral membrane. Bisulfite sequencing of the MD-2 promoter demonstrated methylation of CpG dinucleotides. Inhibition of methylation by 5-azacytidine and histone de-actylation by trichostatin A, two forms of epigenetic silencing, resulted in increased mRNA expression of MD-2 in IECs. These results demonstrate various molecular mechanisms by which IECs down-regulate MD-2 and, thereby, protect against dysregulated inflammation to commensal bacteria in the intestinal lumen,

Original languageEnglish
Pages (from-to)93-103
Number of pages11
JournalInnate Immunity
Volume16
Issue number2
DOIs
StatePublished - Apr 1 2010

Fingerprint

Toll-Like Receptor 4
Epithelial Cells
Lipopolysaccharides
Inflammatory Bowel Diseases
Epigenomics
Messenger RNA
Methylation
trichostatin A
Down-Regulation
Intestinal Secretions
Inflammation
Azacitidine
Intestinal Mucosa
Gram-Negative Bacteria
Histones
Transcriptional Activation
Cytokines
Bacteria
Gene Expression
Cell Line

Keywords

  • Histone de-acetylation
  • Intestinal epithelial cells
  • Lipopolysaccharide
  • MD-2
  • Methylation
  • Toll-like receptor 4 (TLR4)

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology
  • Immunology
  • Microbiology
  • Infectious Diseases

Cite this

Regulation of Toll-like receptor 4-associated MD-2 in intestinal epithelial cells : A comprehensive analysis. / Vamadevan, Arunan S.; Fukata, Masayuki; Arnold, Elizabeth T.; Thomas, Lisa S.; Hsu, David; Abreu, Maria T.

In: Innate Immunity, Vol. 16, No. 2, 01.04.2010, p. 93-103.

Research output: Contribution to journalArticle

Vamadevan, Arunan S. ; Fukata, Masayuki ; Arnold, Elizabeth T. ; Thomas, Lisa S. ; Hsu, David ; Abreu, Maria T. / Regulation of Toll-like receptor 4-associated MD-2 in intestinal epithelial cells : A comprehensive analysis. In: Innate Immunity. 2010 ; Vol. 16, No. 2. pp. 93-103.
@article{3e88215f360841399257c298c5dca0f8,
title = "Regulation of Toll-like receptor 4-associated MD-2 in intestinal epithelial cells: A comprehensive analysis",
abstract = "The intestinal epithelium maintains a state of controlled inflammation despite continuous contact with Gram-negative commensal bacteria and lipopolysaccharide (LPS) on its luminal surface. Recognition of LPS by the Toll-like receptor (TLR) 4/MD-2 complex results in pro-inflammatory gene expression and cytokine secretion in intestinal epithelial cells (IECs). We have shown that IECs express low levels of MD-2 and TLR4 and are poorly responsive to LPS. In this study, we did a comprehensive analysis to understand the immune-mediated and epigenetic mechanisms by which IECs down-regulate MD-2 expression. Expression of MD-2 and TLR4 mRNA was examined in human inflammatory bowel disease and intestinal epithelial cell lines (T84, HT-29, Caco-2). Nuclear factor-KB transcriptional activation was used as a measure of LPS responsiveness. Intestinal epithelial cells in patients with inflammatory bowel disease exhibited increased expression of MD-2 and TLR4 mRNA. Lipopolysaccharide responsiveness in IECs was polarized to the basolateral membrane. Bisulfite sequencing of the MD-2 promoter demonstrated methylation of CpG dinucleotides. Inhibition of methylation by 5-azacytidine and histone de-actylation by trichostatin A, two forms of epigenetic silencing, resulted in increased mRNA expression of MD-2 in IECs. These results demonstrate various molecular mechanisms by which IECs down-regulate MD-2 and, thereby, protect against dysregulated inflammation to commensal bacteria in the intestinal lumen,",
keywords = "Histone de-acetylation, Intestinal epithelial cells, Lipopolysaccharide, MD-2, Methylation, Toll-like receptor 4 (TLR4)",
author = "Vamadevan, {Arunan S.} and Masayuki Fukata and Arnold, {Elizabeth T.} and Thomas, {Lisa S.} and David Hsu and Abreu, {Maria T}",
year = "2010",
month = "4",
day = "1",
doi = "10.1177/1753425909339231",
language = "English",
volume = "16",
pages = "93--103",
journal = "Innate Immunity",
issn = "1753-4259",
publisher = "SAGE Publications Ltd",
number = "2",

}

TY - JOUR

T1 - Regulation of Toll-like receptor 4-associated MD-2 in intestinal epithelial cells

T2 - A comprehensive analysis

AU - Vamadevan, Arunan S.

AU - Fukata, Masayuki

AU - Arnold, Elizabeth T.

AU - Thomas, Lisa S.

AU - Hsu, David

AU - Abreu, Maria T

PY - 2010/4/1

Y1 - 2010/4/1

N2 - The intestinal epithelium maintains a state of controlled inflammation despite continuous contact with Gram-negative commensal bacteria and lipopolysaccharide (LPS) on its luminal surface. Recognition of LPS by the Toll-like receptor (TLR) 4/MD-2 complex results in pro-inflammatory gene expression and cytokine secretion in intestinal epithelial cells (IECs). We have shown that IECs express low levels of MD-2 and TLR4 and are poorly responsive to LPS. In this study, we did a comprehensive analysis to understand the immune-mediated and epigenetic mechanisms by which IECs down-regulate MD-2 expression. Expression of MD-2 and TLR4 mRNA was examined in human inflammatory bowel disease and intestinal epithelial cell lines (T84, HT-29, Caco-2). Nuclear factor-KB transcriptional activation was used as a measure of LPS responsiveness. Intestinal epithelial cells in patients with inflammatory bowel disease exhibited increased expression of MD-2 and TLR4 mRNA. Lipopolysaccharide responsiveness in IECs was polarized to the basolateral membrane. Bisulfite sequencing of the MD-2 promoter demonstrated methylation of CpG dinucleotides. Inhibition of methylation by 5-azacytidine and histone de-actylation by trichostatin A, two forms of epigenetic silencing, resulted in increased mRNA expression of MD-2 in IECs. These results demonstrate various molecular mechanisms by which IECs down-regulate MD-2 and, thereby, protect against dysregulated inflammation to commensal bacteria in the intestinal lumen,

AB - The intestinal epithelium maintains a state of controlled inflammation despite continuous contact with Gram-negative commensal bacteria and lipopolysaccharide (LPS) on its luminal surface. Recognition of LPS by the Toll-like receptor (TLR) 4/MD-2 complex results in pro-inflammatory gene expression and cytokine secretion in intestinal epithelial cells (IECs). We have shown that IECs express low levels of MD-2 and TLR4 and are poorly responsive to LPS. In this study, we did a comprehensive analysis to understand the immune-mediated and epigenetic mechanisms by which IECs down-regulate MD-2 expression. Expression of MD-2 and TLR4 mRNA was examined in human inflammatory bowel disease and intestinal epithelial cell lines (T84, HT-29, Caco-2). Nuclear factor-KB transcriptional activation was used as a measure of LPS responsiveness. Intestinal epithelial cells in patients with inflammatory bowel disease exhibited increased expression of MD-2 and TLR4 mRNA. Lipopolysaccharide responsiveness in IECs was polarized to the basolateral membrane. Bisulfite sequencing of the MD-2 promoter demonstrated methylation of CpG dinucleotides. Inhibition of methylation by 5-azacytidine and histone de-actylation by trichostatin A, two forms of epigenetic silencing, resulted in increased mRNA expression of MD-2 in IECs. These results demonstrate various molecular mechanisms by which IECs down-regulate MD-2 and, thereby, protect against dysregulated inflammation to commensal bacteria in the intestinal lumen,

KW - Histone de-acetylation

KW - Intestinal epithelial cells

KW - Lipopolysaccharide

KW - MD-2

KW - Methylation

KW - Toll-like receptor 4 (TLR4)

UR - http://www.scopus.com/inward/record.url?scp=77952381089&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77952381089&partnerID=8YFLogxK

U2 - 10.1177/1753425909339231

DO - 10.1177/1753425909339231

M3 - Article

C2 - 19710105

AN - SCOPUS:77952381089

VL - 16

SP - 93

EP - 103

JO - Innate Immunity

JF - Innate Immunity

SN - 1753-4259

IS - 2

ER -