Increased susceptibility of annexin-A1 null mice to nociceptive pain is indicative of a spinal antinociceptive action of annexin-A1.
Br J Pharmacol
; 154(5): 1135-42, 2008 Jul.
Article
em En
| MEDLINE
| ID: mdl-18469846
ABSTRACT
BACKGROUND AND PURPOSE:
Annexin-A1 (ANXA1), a glucocorticoid-regulated protein, mediates several of the anti-inflammatory actions of the glucocorticoids. Previous studies demonstrated that ANXA1 is involved in pain modulation. The current study, using ANXA1 knockout mice (ANXA1-/-), is aimed at addressing the site and mechanism of the modulatory action of ANXA1 as well as possible involvement of ANXA1 in mediating the analgesic action of glucocorticoids. EXPERIMENTALAPPROACH:
The acetic acid-induced writhing response was performed in ANXA1-/- and wild-type (ANXA1+/+) mice with spinal and brain levels of prostaglandin E2 (PGE2) examined in both genotypes. The effect of the ANXA1 peptomimetic Ac2-26 as well as methylprednisolone on the writhing response and on spinal cord PGE2 of ANXA1+/+ and ANXA1-/- was compared. The expression of proteins involved in PGE2 synthesis, cytosolic phospholipase A2 (cPLA2) and cyclooxygenases (COXs), in the spinal cord of ANXA1+/+ and ANXA1-/- was also compared. KEYRESULTS:
ANXA1-/- mice exhibited a significantly greater writhing response and increased spinal cord levels of PGE2 compared with ANXA1+/+ mice. Ac2-26 produced analgesia and reduced spinal PGE2 levels in ANXA1+/+ and ANXA1-/- mice, whereas methylprednisolone reduced the writhing response and spinal PGE2 levels in ANXA1+/+, but not in ANXA1-/- mice. The expression of cPLA2, COX-1, COX-2 and COX-3 in spinal cord tissues was upregulated in ANXA1-/-compared with ANXA1+/+. CONCLUSIONS AND IMPLICATIONS We conclude that ANXA1 protein modulates nociceptive processing at the spinal level, by reducing synthesis of PGE2 by modulating cPLA2 and/or COX activity. The analgesic activity of methylprednisolone is mediated by spinal ANXA1.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dor
/
Medula Espinal
/
Anexina A1
/
Analgésicos
Limite:
Animals
Idioma:
En
Revista:
Br J Pharmacol
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Reino Unido