Korean J Intern Med.  2018 Jan;33(1):81-90. 10.3904/kjim.2015.409.

Infection of human intestinal epithelial cells by invasive bacteria activates NF-κB and increases ICAM-1 expression through NOD1

• Shin WG
• Park BJ
• Lee SJ
• Kim JG

• KMID: 2411512
• DOI: http://doi.org/10.3904/kjim.2015.409

Abstract

BACKGROUND/AIMS
Nucleotide-binding oligomerization domain 1 (NOD1) is required for primary intestinal epithelial cells (IECs) to respond to natural mucopeptides secreted by gram-negative bacteria. Infection of human IECs with invasive bacteria up-regulates intercellular adhesion molecule-1 (ICAM-1) expression. However, the role of NOD family members in host defense has been largely unknown. The aim of this study was to determine whether there is a functional role for NOD1 in the up-regulation of ICAM-1 expression in invasive bacteria-infected IECs.
METHODS
ICAM-1 mRNA expression was compared between controls, Caco-2 or HT29 cells transfected with an empty vector, and IECs stably transfected with a dominant-negative (DN) NOD1. Expression was compared using qualitative reverse transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, and flow cytometry after infection with enteroinvasive Escherichia coli O29:NM or Shigella flexneri. Nuclear factor kB (NF-κB) activation was determined by electrophoretic mobility shift assays.
RESULTS
DN NOD1 significantly inhibited the up-regulation of ICAM-1 expression in response to an enteroinvasive bacterial infection. The Caco-2 cells transfected with DN NOD1 manifested marked inhibition of NF-kB activation in response to E. coli O29:NM infection.
CONCLUSIONS
Signaling through NOD1 may play an essential role in neutrophil trafficking following infection with enteroinvasive bacteria.

Keyword

Intercellular adhesion molecule-1; NOD1 protein; Escherichia coli; Shigella flexneri

MeSH Terms

Bacteria*
Bacterial Infections
Caco-2 Cells
Electrophoretic Mobility Shift Assay
Epithelial Cells*
Escherichia coli
Flow Cytometry
Gram-Negative Bacteria
HT29 Cells
Humans*
Intercellular Adhesion Molecule-1*
Neutrophils
NF-kappa B
Polymerase Chain Reaction
Reverse Transcription
RNA, Messenger
Shigella flexneri
Up-Regulation
Intercellular Adhesion Molecule-1
NF-kappa B
RNA, Messenger