Elsevier

Neuroscience Letters

Volume 231, Issue 2, 8 August 1997, Pages 83-86
Neuroscience Letters

Nerve growth factor (NGF) expression in rat microglia is induced by adenosine A2a-receptors

https://doi.org/10.1016/S0304-3940(97)00545-4Get rights and content

Abstract

Microglial response to stimuli is characterized by secretion of both neurotoxic and neurotrophic factors. Various adenosine receptor agonists stimulated the production of nerve growth factor (NGF) in microglia. Using reverse transcription-polymerase chain reaction (RT-PCR)- and ELISA-techniques, we show that the mixed A1- and A2-agonist 5′-(N-ethylcarboxamido)-adenosine (NECA) induces an increase in NGF mRNA expression and NGF protein release. Whereas the A1-specific agonist cyclopentyladenosine (CPA) only minimally affected NGF release, the A2a-specific agonist CGS-21680 triggered the greatest increase in microglial NGF synthesis. Analyzing the selective antagonist (E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylxanthine (EXIP), as well as modulators of the cyclic AMP (cAMP) pathway, we identified an adenosine A2a-receptor-sensitive, cAMP-mediated mechanism of microglial NGF synthesis. Our results indicate that A2a-adenosine receptors modulate microglial neurotrophin expression and release.

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Acknowledgements

This study was supported by the Swiss National Foundation for Scientific Research (Grant 3100-049397.96-1), by Deutsche Forschungsgesellschaft (SFB 505/B1, B5 and Li643/2-1) and by Bundesministerium für Forschung und Technologie/BMFT (Grant 01 KL 9303/1).

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