The role of TNF-alpha and its receptors in the production of beta-1,4 galactosyltransferase I and V mRNAs by rat primary astrocytes

J Mol Neurosci. 2007;33(2):155-62. doi: 10.1007/s12031-007-0033-4.

Abstract

Glycosylation is one of the most important post-translational modifications. It is clear that the single step of beta-1,4-galactosylation is performed by a family of beta-1, 4-galactosyltransferases (beta-1,4-GalTs), and that each member of this family may play a distinct role in different tissues and cells. beta-1,4-GalT I and V are involved in the biosynthesis of N-linked oligosaccharides. beta-1,4-GalT I and V mRNAs are present in control astrocytes and affected by TNF-alpha and lipopolysaccharide (LPS) stimuli. In this study, we examined the regulatory mechanisms of tumor necrosis factor-alpha (TNF-alpha)-affected production of beta-1,4-GalT I and V mRNAs. We show here that cultured astrocytes express TNF-alpha receptor 1 (TNFR1) and increased slightly after exposure to LPS. TNF-alpha and TNFR2 are not detected in control astrocytes and upregulated significantly with LPS stimulation and that activation of these receptors by TNF-alpha affects expressions of beta-1,4-GalT I and V mRNAs. In addition, we observed that not only exogenous TNF-alpha but also TNF-alpha produced by astrocytes affected beta-1,4-GalT I and V mRNAs production in astrocytes. These results suggest that an autocrine loop involving TNF-alpha contributes to the production of beta-1,4-GalT I and V mRNA in response to inflammation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / cytology
  • Astrocytes / physiology*
  • Cells, Cultured
  • Galactosyltransferases* / genetics
  • Galactosyltransferases* / metabolism
  • Lipopolysaccharides / metabolism
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Tumor Necrosis Factor, Type I / genetics
  • Receptors, Tumor Necrosis Factor, Type I / metabolism*
  • Receptors, Tumor Necrosis Factor, Type II / genetics
  • Receptors, Tumor Necrosis Factor, Type II / metabolism*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Lipopolysaccharides
  • RNA, Messenger
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Tumor Necrosis Factor-alpha
  • Galactosyltransferases
  • beta-1,4-galactosyltransferase I
  • beta-1,4-galactosyltransferase V