Inflammation

, Volume 28, Issue 6, pp 345–353

Enteropathogenic Escherichia coli Outer Membrane Proteins Induce iNOS by Activation of NF-κB and MAP Kinases

  • Vasantha Malladi
  • Manjula Puthenedam
  • Peter H. Williams
  • Arun Balakrishnan
Article

DOI: 10.1007/s10753-004-6645-8

Cite this article as:
Malladi, V., Puthenedam, M., Williams, P.H. et al. Inflammation (2004) 28: 345. doi:10.1007/s10753-004-6645-8

Abstract

Enteropathogenic Escherichia coli (EPEC) infects the human intestinal epithelium and is a major cause of infantile diarrhea in developing countries. Nitric oxide (NO) is an important modulator of intestinal inflammatory response. The aim of the present study was to investigate whether EPEC outer membrane proteins (OMPs) up regulate epithelial cell expression of inducible nitric oxide synthase (iNOS) and to examine the role of NF-κB and MAP kinases (MAPK) on nitrite production. iNOS mRNA expression was assessed by RT-PCR. Nitrite levels were measured by Griess reaction. NF-κB activation by OMPs was evaluated by EMSA and immunoblotting was done to detect MAPK activation. EPEC OMP up regulated iNOS, induced nitrite production and NF-κB and MAPK were activated in caco-2 cells. The nitrite levels decreased when NF-κB and MAPK inhibitors were used. Thus, EPEC OMPs induce iNOS expression and NO production through activation of NF-κB and MAPK.

Keywords

EPECiNOSnitric oxideouter membrane proteinNF-κBMAP kinase

Copyright information

© Springer Science + Business Media, Inc. 2004

Authors and Affiliations

  • Vasantha Malladi
    • 1
  • Manjula Puthenedam
    • 1
  • Peter H. Williams
    • 2
  • Arun Balakrishnan
    • 1
  1. 1.Centre for BiotechnologyAnna UniversityChennaiIndia
  2. 2.Department of Microbiology and ImmunologyUniversity of LeicesterUK