Epac1-mediated Rap1 activation is not required for the production of nitric oxide in BV2, murine microglial cells.
J Neurosci Res
; 81(1): 38-44, 2005 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-15931667
This study demonstrates that cyclic AMP (cAMP) production is induced by lipopolysaccharide (LPS) stimulation and activates two different pathways in murine BV2 microglial cells. Two principal effector proteins for cAMP are protein kinase A (PKA) and cAMP-responsive guanine nucleotide exchange factor (Epac), a Rap GDP exchange factor. When cells were treated with various cAMP level modulators, nitric oxide (NO) production increased as the result of posttreatment with Type IV phosphodiesterase (PDE4) inhibitor, rolipram or dibutyryl-cAMP (dbcAMP), at 2 hr after LPS stimulation. Intracellular cAMP increased due to LPS stimulation and the cAMP modulators phosphorylate transcription factor CREB, which is enhanced in turn by posttreatment with dbcAMP. In contrast, the Epac-specific cAMP analog 8-(4-chloro-phenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (8CPT-2Me-cAMP) activates Rap1 in the BV2 cells, but does not induce PKA activation, as judged by CREB phosphorylation. NO production was enhanced by posttreatment with dbcAMP but not by treatment with 8CPT-2Me-cAMP. This suggests that LPS-stimulated NO production is mainly PKA-dependent and also that Epac1-mediated Rap1 activation is not required for the induction of NO production.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Microglía
/
AMP Cíclico
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Proteínas de Unión al GTP rap1
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Factores de Intercambio de Guanina Nucleótido
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Óxido Nítrico
Límite:
Animals
Idioma:
En
Revista:
J Neurosci Res
Año:
2005
Tipo del documento:
Article
Pais de publicación:
Estados Unidos