Microsomal prostaglandin E synthase-1 is overexpressed in inflammatory bowel disease: Evidence for involvement of the transcription factor Egr-1 Academic Article uri icon

Overview

MeSH Major

  • DNA-Binding Proteins
  • Immediate-Early Proteins
  • Inflammatory Bowel Diseases
  • Intramolecular Oxidoreductases
  • Microsomes
  • Transcription Factors

abstract

  • Microsomal prostaglandin E synthase-1 (mPGES-1) catalyzes the conversion of cyclooxygenase-derived prostaglandin (PG) H(2) to PGE(2). Increased amounts of mPGES-1 were detected in inflamed intestinal mucosa from patients with inflammatory bowel disease (IBD). Treatment with tumor necrosis factor (TNF)-alpha stimulated mPGES-1 transcription in human colonocytes, resulting in increased amounts of mPGES-1 mRNA and protein. The inductive effect of TNF-alpha localized to the GC box region of the mPGES-1 promoter. Binding of Egr-1 to the GC box region of the mPGES-1 promoter was enhanced by treatment with TNF-alpha. Notably, increased Egr-1 expression and binding activity were also detected in inflamed mucosa from IBD patients. Treatment with TNF-alpha induced the activities of phosphatidylcholine-phospholipase C (PC-PLC) and protein kinase (PK) C and enhanced NO production. A pharmacological approach was used to implicate PC-PLC --> PKC --> NO signaling as being important for the induction of mPGES-1 by TNF-alpha. TNF-alpha also enhanced guanylate cyclase activity and inhibitors of guanylate cyclase activity blocked the induction of mPGES-1 by TNF-alpha. YC-1, an activator of guanylate cyclase, induced mPGES-1. Overexpressing a dominant negative form of PKG blocked TNF-alpha-mediated stimulation of the mPGES-1 promoter. Taken together, these results suggest that overexpression of mPGES-1 in IBD is the result of Egr-1-mediated activation of transcription. Moreover, TNF-alpha induced mPGES-1 by stimulating PC-PLC --> PKC --> NO --> cGMP --> PKG signal transduction pathway.

publication date

  • March 26, 2004

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1074/jbc.M312972200

PubMed ID

  • 14722058

Additional Document Info

start page

  • 12647

end page

  • 58

volume

  • 279

number

  • 13