Evidence of decreased gap junction coupling between astrocytes and oligodendrocytes in the anterior cingulate cortex of depressed suicides.
Fiche publication
Date publication
novembre 2019
Journal
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
Auteurs
Membres identifiés du Cancéropôle Est :
Dr LUTZ Pierre-Eric
Tous les auteurs :
Tanti A, Lutz PE, Kim J, O'Leary L, Théroux JF, Turecki G, Mechawar N
Lien Pubmed
Résumé
Glial dysfunction is a major pathophysiological feature of mood disorders. While altered astrocyte (AS) and oligodendrocyte-lineage (OL) functions have been associated with depression, the crosstalk between these glial cell types has never been assessed in that context. AS are potent regulators of myelination, in part through gap junction (GJ) channels formed by the heterotypic coupling of AS-specific (Cx30 and Cx43) and OL-specific (Cx32 and Cx47) connexins. This study therefore aimed at addressing the integrity of AS/OL coupling in the anterior cingulate cortex (ACC) of depressed suicides. Using immunofluorescence and confocal imaging, we characterized the distribution of Cx30 and mapped its expression onto OL somas, myelinated axons, and brain vasculature in postmortem brain samples from depressed suicides (N = 48) and matched controls (N = 23). Differential gene expression of key components of the GJ nexus was also screened through RNA-sequencing previously generated by our group, and validated by quantitative real-time PCR. We show that Cx30 expression localized onto OL cells and myelinated fibers is decreased in deep cortical layers of the ACC in male-depressed suicides. This effect was associated with decreased expression of OL-specific connexins, as well as the downregulation of major connexin-interacting proteins essential for the scaffolding, trafficking, and function of GJs. These results provide a first evidence of impaired AS/OL GJ-mediated communication in the ACC of individuals with mood disorders. These changes in glial coupling are likely to have significant impact on brain function, and may contribute to the altered OL function previously reported in this brain region.
Mots clés
Astrocytes, metabolism, Connexin 30, metabolism, Connexins, metabolism, Depressive Disorder, metabolism, Gyrus Cinguli, metabolism, Humans, Nerve Fibers, Myelinated, metabolism, Oligodendroglia, metabolism, Suicide, Completed, psychology
Référence
Neuropsychopharmacology. 2019 11;44(12):2099-2111