Neurotrophin secretion from cultured microglia

J Neurosci Res. 2001 Aug 15;65(4):322-31. doi: 10.1002/jnr.1157.

Abstract

Because microglia have been suggested to produce neurotrophins, we tested this ability in vitro. Rat primary microglia were found to constitutively secrete a limited amount of brain-derived neurotrophic factor (BDNF), but nerve growth factor (NGF) and neurotrophin-3 (NT-3) were undetectable in the conditioned medium. Stimulation of the cells with lipopolysaccharide (LPS) increased BDNF secretion, and induced NGF secretion. As a first step to examine this regulation system, the association of protein kinase C (PKC) was pharmacologically analyzed. A PKC activator, phorbol-12-myristate-13-acetate, enhanced the secretion of BDNF. Pre-treatment of microglia with a PKC inhibitor, bisindolylmaleimide, suppressed LPS-stimulated BDNF secretion as well as the constitutive one. These results suggest that the PKC signaling cascade is closely associated with BDNF secretion. Among PKC isoforms, PKCalpha probably plays a role in BDNF secretion, based on the results of experiments using a specific PKC activator, 1-oleoyl-2-acetyl-sn-glycerol, and a specific PKC inhibitor, Gö 6976, and by immunoblotting. Taken together, these findings suggest that the secretion of BDNF from microglia is regulated through PKCalpha-associated signal transduction mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies
  • Brain-Derived Neurotrophic Factor / analysis
  • Brain-Derived Neurotrophic Factor / immunology
  • Brain-Derived Neurotrophic Factor / metabolism
  • Carbazoles / pharmacology
  • Carcinogens / pharmacology
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Culture Media, Conditioned / pharmacology
  • Diglycerides / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Indoles / pharmacology
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / metabolism
  • Lipopolysaccharides / pharmacology
  • Maleimides / pharmacology
  • Microglia / cytology*
  • Microglia / drug effects
  • Microglia / metabolism*
  • Nerve Growth Factor / analysis
  • Nerve Growth Factor / immunology
  • Nerve Growth Factor / metabolism
  • Nerve Growth Factors / analysis
  • Nerve Growth Factors / immunology
  • Nerve Growth Factors / metabolism*
  • Neurotrophin 3 / analysis
  • Neurotrophin 3 / immunology
  • Neurotrophin 3 / metabolism
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / metabolism
  • Protein Kinase C-alpha
  • Rats
  • Tetradecanoylphorbol Acetate / pharmacology

Substances

  • Antibodies
  • Brain-Derived Neurotrophic Factor
  • Carbazoles
  • Carcinogens
  • Culture Media, Conditioned
  • Diglycerides
  • Enzyme Inhibitors
  • Indoles
  • Isoenzymes
  • Lipopolysaccharides
  • Maleimides
  • Nerve Growth Factors
  • Neurotrophin 3
  • Go 6976
  • 1-oleoyl-2-acetylglycerol
  • Nerve Growth Factor
  • Protein Kinase C
  • Protein Kinase C-alpha
  • bisindolylmaleimide
  • Tetradecanoylphorbol Acetate