The mediating role of KITLG DNA methylation in the association between childhood adversity and cortisol stress reactivity does not replicate in monocytes.

Adverse childhood experiences such as maltreatment or neglect are associated with mental health problems in adulthood. Changes in the regulation of the psychological and physiological stress reaction, mediated via epigenetic modifications, are discussed as potential mechanisms. This study aimed to replicate the role of DNA methylation of the KITLG gene in mediating the association between childhood adversity and stress-induced cortisol reactivity in a sample of adults reporting childhood adversity and a matched control group (N = 60). DNA was extracted from purified CD14+ monocytes and genome-wide DNA methylation was assessed with the 450k BeadChip for targeted replication and exploratory analyses. As previously reported, childhood adversity was associated with significantly lower cortisol reactivity to stress. We could neither replicate the association between KITLG DNA methylation and cortisol stress reactivity nor the association with childhood adversity. Moreover, DNA methylation of the target CpG (cg27512205) was not associated with KITLG mRNA expression in monocytes. Exploratory analyses of array-wide DNA methylation patterns showed no significant results for individual sites after correction for multiple testing - neither in association with childhood trauma nor with adult cortisol stress reactivity. The analysis of differentially methylated regions (DMRs) revealed two significant regions which both mapped to non-coding genes in the association with cortisol stress reactivity. The mediating role of DNA methylation of the KITLG locus in the association between childhood adversity and cortisol stress reactivity could not be replicated in monocytes. In addition to differences in investigated tissue, reasons for non-replication might include differences between samples in age, ethnicity, trauma severity, and cortisol reactivity.

Oxytocin administration and emotion recognition abilities in adults with a history of childhood adversity.

Adverse childhood experience such as neglect or abuse can lead to long-term deficits in emotion processing abilities. Animal studies indicate that oxytocin production and/or sensitivity are influenced by variation in early nurturing experiences. The goal of this study was to test whether emotion recognition abilities and empathy might be improved via intranasal oxytocin administration in adults with a history of childhood maltreatment. We assessed a total of 80 healthy participants, half with and half without a history of childhood adversity. Participants performed the Reading the Mind in the Eyes Test (RMET) and an emotion recognition task under 24 IU intranasal oxytocin and placebo, using a double-blind crossover study design. In the first of two sessions, both groups profited equally form oxytocin administration and showed greater accuracy under oxytocin compared to placebo in the RMET (p = .049). In the emotion recognition task, only the early adversity group benefited significantly from oxytocin administration in the first session (p = .035), mainly due to more accurate recognition of angry and fearful facial expression. Our findings show that emotion processing abilities might be improved via oxytocin administration in adults reporting adverse childhood experiences.

Altered Stress-Induced Regulation of Genes in Monocytes in Adults with a History of Childhood Adversity.

Exposure to serious or traumatic events early in life can lead to persistent alterations in physiological stress response systems, including enhanced cross talk between the neuroendocrine and immune system. These programming effects may be mechanistically involved in mediating the effects of adverse childhood experience on disease risk in adulthood. We investigated hormonal and genome-wide mRNA expression responses in monocytes to acute stress exposure, in a sample of healthy adults (n=30) with a history of early childhood adversity, and a control group (n=30) without trauma experience. The early adversity group showed altered hypothalamus-pituitary-adrenal axis responses to stress, evidenced by lower ACTH and cortisol responses. Analyses of gene expression patterns showed that stress-responsive transcripts were enriched for genes involved in cytokine activity, cytokine-cytokine receptor interaction, chemokine activity, and G-protein coupled receptor binding. Differences between groups in stress-induced regulation of gene transcription were observed for genes involved in steroid binding, hormone activity, and G-protein coupled receptor binding. Transcription factor binding motif analysis showed an increased activity of pro-inflammatory upstream signaling in the early adversity group. We also identified transcripts that were differentially correlated with stress-induced cortisol increases between the groups, enriched for genes involved in cytokine-cytokine receptor interaction and glutamate receptor signaling. We suggest that childhood adversity leads to persistent alterations in transcriptional control of stress-responsive pathways, which-when chronically or repeatedly activated-might predispose individuals to stress-related psychopathology.