Child abuse associates with an imbalance of oligodendrocyte-lineage cells in ventromedial prefrontal white matter

• Published in: Molecular psychiatry 2018-10, Vol.23 (10), p.2018-2028
• Main Authors: Tanti, A, Kim, J J, Wakid, M, Davoli, M-A, Turecki, G, Mechawar, N
• Format: Article
• Language: English
• Subjects: Adult; Adult Survivors of Child Abuse - psychology; Adverse Childhood Experiences; Analysis; ASCL1 protein; Basic Helix-Loop-Helix Transcription Factors - physiology; Behavioral Sciences; Biological Psychology; Brain; Brain - pathology; Cell Lineage; Child abuse; Child abuse & neglect; Female; Fluorescent antibody technique; Humans; Immunoblotting; Immunofluorescence; Male; Medicine; Medicine & Public Health; Mental depression; Mental disorders; Middle Aged; Myelin; Myelin Sheath - metabolism; Neural networks; Neuroimaging; Neurology; Neurosciences; Oligodendrocytes; Oligodendroglia - drug effects; Oligodendroglia - pathology; Pharmacotherapy; Phenotypes; Prefrontal Cortex - pathology; Prevalence studies (Epidemiology); Psychiatry; Psychological aspects; Risk factors; Stem Cells - metabolism; Substantia alba; Suicidal behavior; Suicide; Suicide - psychology; Suicides & suicide attempts; White Matter - pathology; Young Adult
• ISSN: 1359-4184; 1476-5578
• DOI: 10.1038/mp.2017.231

Child abuse (CA) is a major risk factor for depression, and strongly associates with suicidal behavior during adulthood. Neuroimaging studies have reported widespread changes in white matter integrity and brain connectivity in subjects with a history of CA. Although such observations could reflect changes in myelin and oligodendrocyte function, their cellular underpinnings have never been addressed. Using postmortem brain samples from depressed suicides with or without history of CA and matched controls (18 per group), we aimed to characterize the effects of CA on oligodendrocyte-lineage (OL) cells in the ventromedial prefrontal white matter. Using immunoblotting, double-labeling immunofluorescence and stereological estimates of stage-specific markers, we found that CA is associated with increased numbers of mature myelinating oligodendrocytes, accompanied by decreased numbers of more immature OL cells. This was paralleled by an increased expression of transcription factor MASH1, which is involved in the terminal differentiation of the OL, suggesting that CA may trigger an increased maturation, or bias the populations of OL cells toward a more mature phenotype. Some of these effects, which were absent in the brain of depressed suicides with no history of CA, were also found to recover with age, suggesting that changes in the balance of the OL may reflect a transient adaptive mechanism triggered by early-life adversity. In conclusion, our results indicate that CA in depressed suicides is associated with an imbalance of the OL in the ventromedial prefrontal white matter, an effect that could lead to myelin remodeling and long-term connectivity changes within the limbic network.