Increased functional coupling of the mu opioid receptor in the anterior insula of depressed individuals.
Fiche publication
Date publication
avril 2021
Journal
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Auteurs
Membres identifiés du Cancéropôle Est :
Dr LUTZ Pierre-Eric
Tous les auteurs :
Lutz PE, Almeida D, Filliol D, Jollant F, Kieffer BL, Turecki G
Lien Pubmed
Résumé
The mu opioid receptor (MOR) is a G protein-coupled receptor that plays an essential role in reward and hedonic processes, and that has been implicated in disorders such as depression and addiction. Over the last decade, several brain imaging studies in depressed patients have consistently found that dysregulation of MOR function occurs in particular in the anterior insular cortex, an important brain site for the perception of internal states and emotional regulation. To investigate molecular mechanisms that may underlie these effects, here we assessed genetic polymorphisms, expression, and functional G-protein coupling of MOR in a large post-mortem cohort (N = 95) composed of depressed individuals who died by suicide, and healthy controls. Results indicated that depression, but not comorbid substance use disorder or acute opiate consumption, was associated with increased MOR activity. This effect was partly explained by a specific increase in expression of the inhibitory alpha G-protein subunit GNAI2. Consistent with previous neuroimaging studies, our findings support the notion that enhanced endogenous opioidergic tone in the anterior insula may buffer negative affective states in depressed individuals, a mechanism that could potentially contribute to the antidepressant efficacy of emerging opioid-based medications.
Mots clés
Analgesics, Opioid, Brain, metabolism, Cerebral Cortex, diagnostic imaging, Emotions, GTP-Binding Protein alpha Subunit, Gi2, metabolism, Humans, Receptors, Opioid, mu, genetics
Référence
Neuropsychopharmacology. 2021 04;46(5):920-927