title: Infection of human intestinal epithelial cells by invasive bacteria activates NF-κB and increases ICAM-1 expression through NOD1.
abstract: 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.
  
  
  
  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 enteroinvasiveEscherichia coliO29:NM orShigella flexneri. Nuclear factor kB (NF-κB) activation was determined by electrophoretic mobility shift assays.
  
  
  
  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 toE. coliO29:NM infection.
  
  
  
  Signaling through NOD1 may play an essential role in neutrophil trafficking following infection with enteroinvasive bacteria.
authors.affiliation: Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Woon Geon
authors.initials: WG
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Bum Joon
authors.initials: BJ
authors.lastname: Park
authors.affiliation: Department of Dentistry, Seoul National University School of Dentistry, Seoul, Korea.
authors.forename: Sung Joong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Jae Gyu
authors.initials: JG
authors.lastname: Kim
mesh_terms: D018938:Caco-2 Cells; D004847:Epithelial Cells / Q000378:metabolism* / Q000382:microbiology*; D004926:Escherichia coli; D019073:HT29 Cells; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007422:Intestines / Q000166:cytology* / Q000382:microbiology; D016328:NF-kappa B / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology; D053474:Nod1 Signaling Adaptor Protein / Q000502:physiology*; D012763:Shigella flexneri
chemical_list: D016328:NF-kappa B; C119067:NOD1 protein, human; D053474:Nod1 Signaling Adaptor Protein; D018799:Intercellular Adhesion Molecule-1
keywords: Escherichia coli; Intercellular adhesion molecule-1; NOD1 protein; Shigella flexneri