Fiche publication
Date publication
avril 2012
Journal
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Auteurs
Membres identifiés du Cancéropôle Est :
Mme KOEBEL Pascale
,
Dr BEFORT Katia
,
Dr DARCQ Emmanuel
Tous les auteurs :
Darcq E, Befort K, Koebel P, Pannetier S, Mahoney MK, Gaveriaux-Ruff C, Hanauer A, Kieffer BL
Lien Pubmed
Résumé
It has been established that mu opioid receptors activate the ERK1/2 signaling cascade both in vitro and in vivo. The Ser/Thr kinase RSK2 is a direct downstream effector of ERK1/2 and has a role in cellular signaling, cell survival growth, and differentiation; however, its role in biological processes in vivo is less well known. Here we determined whether RSK2 contributes to mu-mediated signaling in vivo. Knockout mice for the rsk2 gene were tested for main morphine effects, including analgesia, tolerance to analgesia, locomotor activation, and sensitization to this effect, as well as morphine withdrawal. The deletion of RSK2 reduced acute morphine analgesia in the tail immersion test, indicating a role for this kinase in mu receptor-mediated nociceptive processing. All other morphine effects and adaptations to chronic morphine were unchanged. Because the mu opioid receptor and RSK2 both show high density in the habenula, we specifically downregulated RSK2 in this brain metastructure using an adeno-associated-virally mediated shRNA approach. Remarkably, morphine analgesia was significantly reduced, as observed in the total knockout animals. Together, these data indicate that RSK2 has a role in nociception, and strongly suggest that a mu opioid receptor-RSK2 signaling mechanism contributes to morphine analgesia at the level of habenula. This study opens novel perspectives for both our understanding of opioid analgesia, and the identification of signaling pathways operating in the habenular complex.
Mots clés
Analgesics, Opioid, pharmacology, Analysis of Variance, Animals, Behavior, Animal, drug effects, Drug Tolerance, genetics, Habenula, drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Morphine, pharmacology, Morphine Dependence, drug therapy, Motor Activity, drug effects, Naloxone, pharmacology, Narcotic Antagonists, pharmacology, Nociception, drug effects, Pain Measurement, drug effects, RNA, Small Interfering, genetics, Ribosomal Protein S6 Kinases, 90-kDa, deficiency, Signal Transduction, drug effects, Transduction, Genetic
Référence
Neuropsychopharmacology. 2012 Apr;37(5):1288-96
