The nicotinic acetylcholine receptor agonist (+/-)-epibatidine increases FGF-2 mRNA and protein levels in the rat brain

Brain Res Mol Brain Res. 1999 Dec 10;74(1-2):98-110. doi: 10.1016/s0169-328x(99)00266-1.

Abstract

In a previous work, we showed that acute intermittent nicotine treatment up-regulates the level of fibroblast growth factor-2 (FGF-2) mRNA in brain regions of tel- and mesencephalon of rats suggesting that neuroprotective effect of (-)nicotine may, at least in part, involve an activation of the neuronal FGF-2 signalling. The present experiments were designed to extend the study on the nicotinic receptor mediated up-regulation of FGF-2 mRNA levels to the use of the potent nicotinic acetylcholine receptor (nAChR) agonist (+/-)-epibatidine. The (+/-)-epibatidine treatment led to a strong and long lasting up-regulation of FGF-2 mRNA expression in the cerebral cortex, in the hippocampal formation, in the striatum and in the substantia nigra. This FGF-2 mRNA induction, already statistically significant at 4 h, peaked at 12 h from treatment and was only partially returned towards normal levels at 48 h, the last time point examined. Using Western blot analysis it was found that the epibatidine-induced upregulation of FGF-mRNA is accompaned by an increase of FGF-2 protein level at the 20-h time-interval. These (+/-)-epibatidine effects on FGF-2 expression were antagonized by the non-competitive nAChR antagonist mecamylamine, indicating an involvement of nicotinic receptors. In the same brain areas examined, no changes were observed in the fibroblast growth factor receptor-1 (FGFR-1) mRNA levels, in brain-derived neurotrophic factor (BDNF) and in glial cell line-derived neurotrophic factor (GDNF) mRNA levels. In view of the neurotrophic function of FGF-2, these results, together with previous ones, could further help to understand the molecular mechanisms mediating the previously observed neuroprotective effects of (-)nicotine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Brain / drug effects*
  • Brain / metabolism
  • Brain-Derived Neurotrophic Factor / genetics
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology*
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / metabolism
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism
  • Dose-Response Relationship, Drug
  • Fibroblast Growth Factor 2 / genetics*
  • Fibroblast Growth Factor 2 / metabolism
  • Gene Expression Regulation / drug effects
  • Glial Cell Line-Derived Neurotrophic Factor
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • In Situ Hybridization
  • Mecamylamine / pharmacology
  • Nerve Growth Factors*
  • Nerve Tissue Proteins / genetics
  • Nicotinic Agonists / pharmacology*
  • Nicotinic Antagonists / pharmacology
  • Pyridines / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Specific Pathogen-Free Organisms
  • Time Factors

Substances

  • Brain-Derived Neurotrophic Factor
  • Bridged Bicyclo Compounds, Heterocyclic
  • Gdnf protein, rat
  • Glial Cell Line-Derived Neurotrophic Factor
  • Nerve Growth Factors
  • Nerve Tissue Proteins
  • Nicotinic Agonists
  • Nicotinic Antagonists
  • Pyridines
  • RNA, Messenger
  • Fibroblast Growth Factor 2
  • Mecamylamine
  • epibatidine