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Major depressive disorder (MDD) involves peripheral low-grade pro-inflammatory activity. This multi-biomarker case-control study characterises the proinflammatory status in MDD beyond C-reactive protein (CRP) and Interleukin (IL)-6 levels through investigating concomitant alterations of immunoregulatory biomolecules. In 20 female MDD patients and 24 non-depressed women, circulating levels of CRP, IL-6, cortisol, selected endocannabinoids (ECs; anandamide [AEA], 2-arachidonylglycerol [2-AG]), and N-acylethanolamines (NAEs), as well as circulating cell-free mitochondrial DNA (ccf-mtDNA) were measured. We found higher serum CRP and plasma AEA levels in MDD and a positive association of CRP and AEA levels with current depressive symptoms. Blood levels of cortisol, ccf-mtDNA, 2-AG, and NAEs did depend on MDD diagnosis nor correlated with the severity of current depressive symptoms. CRP correlated positively with AEA, and AEA showed positive associations with 2-AG and NAE levels. In this study, female MDD outpatients with mild to moderate disorder severity did not substantially differ from non-depressed controls in the resting levels of multiple immunoregulatory markers in peripheral blood. Instead of investigating resting levels, future research on the role of inflammatory activity in MDD should focus on investigating the reactivity of pathways modulating the immune system upon exposure to physical and psychosocial stressors.

Small noncoding microRNAs (miRNA) regulate the expression of target mRNAs by repressing their translation or orchestrating their sequence-specific degradation. In this study, we investigated miRNA and miRNA target gene expression patterns in melanoma to identify candidate biomarkers for early and progressive disease. Because data presently available on miRNA expression in melanoma are inconsistent thus far, we applied several different miRNA detection and profiling techniques on a panel of 10 cell lines and 20 patient samples representing nevi and primary or metastatic melanoma. Expression of selected miRNAs was inconsistent when comparing cell line–derived and patient-derived data. Moreover, as expected, some discrepancies were also detected when miRNA microarray data were correlated with qPCR-measured expression levels. Nevertheless, we identified miRNA-200c to be consistently downregulated in melanocytes, melanoma cell lines, and patient samples, whereas miRNA-205 and miRNA-23b were markedly reduced only in patient samples. In contrast, miR-146a and miR-155 were upregulated in all analyzed patients but none of the cell lines. Whole-genome microarrays were performed for analysis of selected melanoma cell lines to identify potential transcriptionally regulated miRNA target genes. Using Ingenuity pathway analysis, we identified a deregulated gene network centered around microphthalmia-associated transcription factor, a transcription factor known to play a key role in melanoma development. Our findings define miRNAs and miRNA target genes that offer candidate biomarkers in human melanoma. Cancer Res; 70(10); 4163–73. ©2010 AACR.

Supplementary Figure 1 from Signatures of MicroRNAs and Selected MicroRNA Target Genes in Human Melanoma

Supplementary Figure 2 from Signatures of MicroRNAs and Selected MicroRNA Target Genes in Human Melanoma

Supplementary Table 1 from Signatures of MicroRNAs and Selected MicroRNA Target Genes in Human Melanoma

Evidence for a genetic influence on psychological treatment outcome so far has been inconsistent, likely due to the focus on candidate genes and the heterogeneity of the disorders treated. Using polygenic risk scores (PRS) in homogenous patient samples may increase the chance of detecting genetic influences. A sample of 342 phobic patients treated either for clinically relevant dental fear (n = 189) or other (mixed) phobic fears (n = 153) underwent highly standardized exposure-based CBT. A brief five-session format was used to treat dental fear, whereas longer multi-session treatments were used with the mixed-fear cohort. PRS were calculated based on large genetic studies of Neuroticism, Educational Attainment (EA), Intelligence, and four psychopathology domains. We compared PRS of post-treatment and follow-up remitters and non-remitters and regressed PRS on fear reduction percentages. In the dental fear cohort, EA PRS were associated with treatment outcomes, i.e. drop-out, short- and long-term remission state, fear reduction, and attendance of subsequent dental appointments. In the mixed fear treatment cohort, no gene effects were observable. Results indicate the importance of EA-related traits for outcomes following brief, but not long, standardized exposure-based CBT. Such use of PRS may help inform selection and tailoring of treatments.

Cell-free mitochondrial DNA (cf-mtDNA) is a marker of inflammatory disease and a predictor of mortality, but little is known about cf-mtDNA in relation to psychobiology. A systematic review of the literature reveals that blood cf-mtDNA varies in response to common real-world stressors including psychopathology, acute psychological stress, and exercise. Moreover, cf-mtDNA is inducible within minutes and exhibits high intra-individual day-to-day variation, highlighting the dynamic regulation of cf-mtDNA levels. We discuss current knowledge on the mechanisms of cf-mtDNA release, its forms of transport ("cell-free" does not mean "membrane-free"), potential physiological functions, putative cellular and neuroendocrine triggers, and factors that may contribute to cf-mtDNA removal from the circulation. A review of in vitro, pre-clinical, and clinical studies shows conflicting results around the dogma that physiological forms of cf-mtDNA are pro-inflammatory, opening the possibility of other physiological functions, including the cell-to-cell transfer of whole mitochondria. Finally, to enhance the reproducibility and biological interpretation of human cf-mtDNA research, we propose guidelines for blood collection, cf-mtDNA isolation, quantification, and reporting standards, which can promote concerted advances by the community. Defining the mechanistic basis for cf-mtDNA signaling is an opportunity to elucidate the role of mitochondria in brain-body interactions and psychopathology.

The oxytocin receptor gene (OXTR) is of interest when investigating the effects of early adversity on DNA methylation. However, there is heterogeneity regarding the selection of the most promising CpG sites to target for analyses. The goal of this study was to determine functionally relevant clusters of CpG sites within the OXTR CpG island in 113 mother-infant dyads, with 58 of the mothers having experienced childhood maltreatment (CM). OXTR DNA methylation and gene expression was analyzed in peripheral/umbilical blood mononuclear cells. Different complexity reduction approaches were used to reduce the 188 CpG sites into clusters of co-methylated sites. Furthermore, associations between OXTR DNA methylation (cluster- and site-specific level) and OXTR gene expression and CM were investigated. Results showed that, first, CpG sections differed strongly regarding their statistical utility for research of individual differences in DNA methylation. Second, cluster analyses and Partial Least Squares (PLS) suggested two clusters consisting of intron1/exon2 and the protein-coding region of exon 3, respectively, as most strongly associated with outcome measures. Third, cross-validated PLS regression explained 7% of variance in CM, with low cross-validated variance explained for the prediction of gene expression. Fourth, very high mother-child correspondence was observed in correlation patterns within the identified clusters, but only modest correspondence outside these clusters. This study characterized the DNA methylation landscape of the OXTR CpG island by highlighting clusters of CpG sites that show desirable statistical properties and predictive value. We provide a Companion Web Application to guide future studies in their choice of CpG sites.

Antenatal synthetic glucocorticoid (sGC) treatment is a potent modifier of the hypothalamic-pituitary-adrenal (HPA) axis. In this context, epigenetic modifications are discussed as potential regulators explaining how prenatal exposure to GCs might translate into persistent changes of HPA axis “functioning”. The purpose of this study was to investigate whether DNA methylation and gene expression profiles of stress-associated genes (NR3C1; FKBP5; SLC6A4) may mediate the persistent effects of sGC on cortisol stress reactivity that have been previously observed. In addition, hair cortisol concentrations (hairC) were investigated as a valid biomarker of long-term HPA axis activity. This cross-sectional study comprised 108 term-born children and adolescents, including individuals with antenatal GC treatment and controls. From whole blood, DNA methylation was analyzed by targeted deep bisulfite sequencing. Relative mRNA expression was determined by RT-qPCR experiments and qBase analysis. Acute stress reactivity was assessed by the Trier Social Stress Test (TSST) measuring salivary cortisol by ELISA and hairC concentrations were determined from hair samples by liquid chromatography coupled with tandem mass spectrometry. First, no differences in DNA methylation and mRNA expression levels of the stress-associated genes between individuals treated with antenatal sGC compared to controls were found. Second, DNA methylation and mRNA expression levels were neither associated with cortisol stress reactivity nor with hairC. These findings do not corroborate the belief that DNA methylation and mRNA expression profiles of stress-associated genes (NR3C1; FKBP5; SLC6A4) play a key mediating role of the persistent effects of sGC on HPA axis functioning.

DNA methylation patterns can be responsive to environmental influences. This observation has sparked interest in the potential for psychological interventions to influence epigenetic processes. Recent studies have observed correlations between DNA methylation changes and therapy outcome. However, most did not control for changes in cell composition. This study had two aims: first, we sought to replicate therapy-associated changes in DNA methylation of commonly assessed candidate genes in isolated monocytes from 60 female patients with post-traumatic stress disorder (PTSD). Our second, exploratory goal was to identify novel genomic regions with substantial pre-to-post intervention DNA methylation changes by performing whole-genome bisulfite sequencing (WGBS) in two patients with PTSD. Equivalence testing and Bayesian analyses provided evidence against physiologically meaningful intervention-associated DNA methylation changes in monocytes of PTSD patients in commonly investigated target genes (NR3C1, FKBP5, SLC6A4, OXTR). Furthermore, WGBS yielded only a limited set of candidate regions with suggestive evidence of differential DNA methylation pre- to post-therapy. These differential DNA methylation patterns did not prove replicable when investigated in the entire cohort. We conclude that there is no evidence for major, recurrent intervention-associated DNA methylation changes in the investigated genes in monocytes of patients with PTSD.

Exposure to acute stress has been shown to result in a shift from declarative toward non-declarative learning, presumably mediated by brain mineralocorticoid receptors (MRs). In this study, we aimed to replicate and extend these findings by investigating the role of stress-associated cortisol secretion on learning behavior. Furthermore, we explored the influence of a well-characterized common single nucleotide polymorphism of the MR gene (rs2070951; minor allele frequency: 49.3%) previously shown to influence MR expression and HPA axis activity. Healthy males (n = 74) were exposed to the Trier Social Stress Test or a control condition prior to performing a probabilistic classification task (Weather Prediction Task). The use of a non-declarative learning strategy continuously increased over the course of the learning task after stress exposure, but leveled in the control condition. The shift toward a non-declarative strategy in the stress group was associated with better learning performance. Higher pre-stress cortisol levels favored the adoption of a non-declarative learning strategy. rs2070951 C/C-carriers in contrast to G-allele carriers exhibited a larger secretion of cortisol under stress. Furthermore, control participants homozygous for the C-allele adopted a non-declarative learning strategy less often than stressed participants, whereas the choice of strategy was independent of stress in G-allele carriers. The failure to switch strategies resulted in poorer performance, suggesting a beneficial effect of stress in dependence of MR variation. Consistent with previous findings, the results provide further support for cortisol as a driving force in coordinating the competition between multiple memory systems under stress.

Prenatal exposure to endocrine disrupting chemicals can interfere with development, and has been associated with social-cognitive functioning and adverse health outcomes later in life. Exposure-associated changes of DNA methylation (DNAm) patterns have been suggested as a possible mediator of this relationship. This study investigated whether prenatal low-dose exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) is associated with altered DNAm patterns across the genome in a Western urban-industrial population. In 142 mother-infant pairs from the Duisburg Birth Cohort Study, PCBs and PCDD/Fs levels were quantified from maternal blood during late pregnancy and associated with DNAm levels in cord blood using the Illumina EPIC beadchip. The epigenome-wide association studies (EWAS) identified 32 significantly differentially methylated positions (DMPs) and eight differentially methylated regions (DMRs) associated with six congeners of PCB and PCDD in females or males (FDRs < 0.05). DMPs and DMRs mapped to genes involved in neurodevelopment, gene regulation, and immune functioning. Weighted gene correlation network analysis (WGCNA) showed 31 co-methylated modules (FDRs < 0.05) associated with one congener of PCDF levels in females. Results of both analytical strategies indicate that prenatal exposure to PCBs and PCDD/Fs is associated with altered DNAm of genes involved in neurodevelopment, gene expression and immune functioning. DNAm and gene expression levels of several of these genes were previously associated with EDC exposure in rodent models. Follow-up studies will clarify whether these epigenetic changes might contribute to the origin for adverse mental and health outcomes.

DNA methylation patterns can be responsive to environmental influences. This observation has sparked interest in the potential for psychological interventions to influence epigenetic processes. Recent studies have observed correlations between DNA methylation changes and therapy out-come. However, most did not control for changes in cell composition from pre- to post-therapy. This study had two aims: first, we sought to replicate therapy-associated changes in DNA methylation of commonly assessed candidate genes in isolated monocytes from 60 female patients with post-traumatic stress disorder (PTSD) using targeted deep bisulfite sequencing (DBS). Our second, exploratory goal was to identify novel genomic regions with substantial pre-to-post intervention DNA methylation changes by performing whole-genome bisulfite sequencing (WGBS) in two patients with PTSD and three patients with anorexia nervosa (AN) before and after intervention. Equivalence testing and Bayesian analyses provided evidence against physiologically meaningful intervention associated DNA methylation changes in monocytes of PTSD patients in commonly investigated target genes (NR3C1, FKBP5, SLC6A4, OXTR). Furthermore, WGBS yielded only a limited set of candidate regions with suggestive evidence of differential methylation pre- to post-therapy. These differential methylation patterns did not prove replicable when investigated in the entire cohort. We conclude that there is no evidence for major, recurrent intervention-associated DNA methylation changes in the investigated genes in monocytes of patients with either PTSD or AN.Author SummaryMany mental health problems have developmental origin, and epigenetic mechanisms have been proposed to explain the link between stressful or adverse experiences and subsequent health outcomes. More recently, studies have begun to examine whether psychological therapies might influence or even reverse supposedly acquired DNA methylation marks. Correlations between response to therapy and DNA methylation changes in peripheral tissue have been reported; however, these results might be confounded by differences in cell composition between time points and not reflect true DNA methylation changes. Here, we attempted to replicate previous reported results in a homogenous cell population (monocytes) and further to identify novel intervention-responsive regions in the whole genome in patients with post-traumatic stress disorder (PTSD) and anorexia nervosa (AN).Our results showed that the improvement in symptomatology in PTSD and AN patients was not reflected in changes in DNA methylation in monocytes, neither in the previously studied candidate genes nor in the regions identified by whole-genome bisulfite sequencing. This study provides evidence against DNA methylation changes in peripheral tissue following therapy, and we suggest that previous findings are most likely explained by differences in cell composition.

Animal-fMRI is a powerful method to understand neural mechanisms of cognition, but it remains a major challenge to scan actively participating small animals under low-stress conditions. Here, we present an event-related functional MRI platform in awake pigeons using single-shot RARE fMRI to investigate the neural fundaments for visually-guided decision making. We established a head-fixated Go/NoGo paradigm, which the animals quickly learned under low-stress conditions. The animals were motivated by water reward and behavior was assessed by logging mandibulations during the fMRI experiment with close to zero motion artifacts over hundreds of repeats. To achieve optimal results, we characterized the species-specific hemodynamic response function. As a proof-of-principle, we run a color discrimination task and discovered differential neural networks for Go-, NoGo-, and response execution-phases. Our findings open the door to visualize the neural fundaments of perceptual and cognitive functions in birds—a vertebrate class of which some clades are cognitively on par with primates., Functional magnetic resonance imaging (fMRI) is a powerful method to understand neural mechanisms of cognition but imaging of small animals can be challenging. The authors present an event-related fMRI platform to visualize the neural fundaments of perceptual and cognitive functions in awake birds.

DNA methylation analysis is increasingly used in stress research. Available methods are expensive, laborious and often limited by either the analysis of short CpG stretches or low assay sensitivity. Here, we present a cost-efficient next generation sequencing-based strategy for the simultaneous investigation of multiple candidate genes in large cohorts. To illustrate the method, we present analysis of four candidate genes commonly assessed in psychoneuroendocrine research: Glucocorticoid receptor (NR3C1), Serotonin transporter (SLC6A4), FKBP Prolyl isomerase 5 (FKBP5), and the Oxytocin receptor (OXTR).DNA methylation standards and DNA of a female and male donor were bisulfite treated in three independent trials and were used to generate sequencing libraries for 42 CpGs from the NR3C1 1F promoter region, 83 CpGs of the SLC6A4 5’ regulatory region, 5 CpGs located in FKBP5 intron 7, and additional 12 CpGs located in a potential enhancer element in intron 3 of the OXTR. In addition, DNA of 45 patients with borderline personality disorder (BPD) and 45 healthy controls was assayed. Multiplex libraries of all samples were sequenced on a MiSeq system and analyzed for mean methylation values of all CpG sites using amplikyzer2 software.Results indicated excellent accuracy of the assays when investigating replicates generated from the same bisulfite converted DNA, and very high linearity (R2> 0.9) of the assays shown by the analysis of differentially methylated DNA standards. Comparing DNA methylation between BPD and healthy controls revealed no biologically relevant differences.The technical approach as described here facilitates targeted DNA methylation analysis and represents a highly sensitive, cost-efficient and high throughput tool to close the gap between coverage and precision in epigenetic research of stress-associated phenotypes.

Handedness is a complex trait influenced by both genetic and non-genetic factors. Asymmetries of DNA methylation and gene expression in the developing foetus are thought to underlie its development. However, its molecular epigenetics are not well understood. We collected buccal cells from adult left- and right-handers (n = 60) to investigate whether epigenetic biomarkers of handedness can be identified in non-neuronal tissue. We associated DNA methylation in promoter regions of candidate genes with handedness direction. Results indicate that DNA methylation of genes asymmetrically expressed in the foetal brain or spinal cord might play a role within such a multifactorial model. Moreover, we provide tentative evidence that birth stress might be a factor that affects DNA methylation in NEUROD6, a gene that is asymmetrically expressed in foetal brains.

Objective According to the Interpersonal Psychological Theory of Suicide, capability for suicide comprises two dimensions: fearlessness about death and elevated pain tolerance. The short (S) allelic variant of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) has repeatedly been associated with more violent and lethal suicide methods and lethality of suicide attempts. The current study aimed to investigate whether 5-HTTLPR allelic variants are associated with fearlessness about death and pain tolerance/persistence and whether it moderates the relationship between childhood maltreatment and acquired capability for suicide. Method A cohort of 208 inpatients hospitalized due to a recent suicide attempt or severe suicidal ideation was genotyped for the 5-HTTLPR and assessed for childhood maltreatment. Subjective pain tolerance and fearlessness about death as well as objective pain persistence was assessed using a pressure algometer. Results Fearlessness about death, pain tolerance, and pain persistence did not differ between 5-HTTLPR genotypes. However, there was a significant correlation between self-reported childhood maltreatment and fearlessness about death that emerged exclusively in homozygous S-allele carriers. Conclusion Results suggest that there are no "high-risk"-alleles that generally increase capability for suicide. However, in terms of future suicide-related behaviors exposure to childhood maltreatment events could exert a particularly negative influence on homozygous S-allele carriers by increasing their fearlessness about death.

Transcriptional memory describes an ancient and highly conserved form of cellular learning that enables cells to benefit from recent experience by retaining a mitotically inheritable but reversible memory of the initial transcriptional response when encountering an environmental or physiological stimulus. Herein, we will review recent progress made in the understanding of how cells can make use of diverse constituents of the epigenetic toolbox to retain a transcriptional memory of past states and perturbations. Specifically, we will outline how these mechanisms will help to improve our understanding of skeletal muscle plasticity in health and disease. We describe the epigenetic road map that allows skeletal muscle fibers to navigate through training-induced adaptation processes, and how epigenetic memory marks can preserve an autobiographical history of lifestyle behavior changes, pathological challenges, and aging. We will further consider some key findings in the field of exercise epigenomics to emphasize major challenges when interpreting dynamic changes in the chromatin landscape in response to acute exercise and training.

Schizophrenia patients have a higher probability of altered structural and functional differences between the left and right hemisphere. Schizotypy as its nonclinical manifestation has been related to a higher incidence of non-right-handedness and atypical right-hemispheric language dominance. It has been suggested that genes involved in cilia function might link brain asymmetry and neurodevelopmental disorders. We assessed DNA methylation in the promoter regions of seven candidate genes involved in cilia function and psychiatric disorders from buccal cells and investigated their association with schizotypy and language lateralization in 60 healthy adults. Moreover, we determined microstructural properties of the planum temporale in a subsample of 52 subjects using neurite orientation dispersion and density imaging (NODDI). We found a significant association between schizotypy and DNA methylation in the AHI1 promoter region. Moreover, AHI1 DNA methylation significantly predicted language lateralization and asymmetry in estimated planum temporale neurite density. Finally, stronger leftward asymmetry in estimated neurite density was associated with a more pronounced right ear advantage (left hemisphere dominance) in the forced-right condition of the dichotic listening task, measuring attentional modulation of language lateralization. Our results are in line with a shared molecular basis of schizotypy and functional hemispheric asymmetries that is based on cilia function.

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.

Handedness and language lateralization are the most investigated phenotypes among functional hemispheric asymmetries, i.e. differences in function between the left and the right half of the human brain. Both phenotypes are left hemisphere-dominant, while investigations of the molecular factors underlying right hemisphere-dominant phenotypes are less prominent. In the classical line bisection task, healthy subjects typically show a leftward attentional bias due to a relative dominance of the right hemisphere for visuospatial attention. Based on findings of variations in dopamine-related genes affecting performance in the line bisection task, we first tested whether DNA methylation in non-neuronal tissue in the promoter regions of \(\it DBH\), \(\it SLC6A3\), and \(\it DRD2\) are associated with line bisection deviation. We replicated the typical behavioral pattern and found an effect of DNA methylation in the DBH promoter region on line bisection deviation in right-aligned trials. A second exploratory analysis indicated that an overall DNA methylation profile of genes involved in dopamine function predicts line bisection performance in right-aligned trials. Genetic variation in dopamine-related genes has been linked to attention deficit hyperactivity disorder (ADHD), a neurodevelopmental trait associated with rightward attentional bias. Overall, our findings point towards epigenetic markers for functional hemispheric asymmetries in non-neuronal tissue not only for left hemisphere-dominant, but also for right hemisphere-dominant phenotypes.

Previous research has associated genetic variations of the oxytocin receptor with individual differences in human social behavior. Specifically, homozygous carriers of the G-allele of the single nucleotide polymorphism rs53576 have been reported to display more trust, empathy, and prosocial behavior and were less sensitive toward stress and maltreatment during childhood when compared to A-allele carriers. With regard to Borderline Personality Disorder (BPD), a psychiatric condition that is often associated with the experience of childhood adversity, it has been suggested that A-allele carriers are more vulnerable to developing psychopathological signs and symptoms. In the present study we investigated whether childhood trauma, as assessed by the Childhood Trauma Questionnaire (CTQ), affects empathy for somatic and psychological pain, and how this is moderated by genotype, in a sample of 302 individuals (148 of whom were diagnosed with BPD). We found a three-way interaction between genotype, group and pain condition. Posthoc comparisons revealed that patients with BPD carrying at least one A-allele, rated psychological pain as more intense compared to controls, whereas no difference between groups emerged in GG homozygotes. Moreover, a moderating effect of genotype appeared on the impact of childhood trauma on empathy for psychological pain. In addition, a positive correlation of CTQ scores and empathy appeared only in A-allele carriers (GA + AA), independent of diagnosis. Together, A-allele carriers, especially those with BPD, seemed to be responsive to the impact of adversity on empathy-for-pain, while GG homozygotes were not, which is compatible with the idea of differential susceptibility.

There is considerable interindividual variation in response to psychotherapeutical intervention. In order to realize the long-term goal of personalised treatment approaches, it is important to identify behavioural and biological moderators and mediators of treatment responses. Here, we tested the predictive value of experimental fear extinction efficacy as well as the role of genetic variation of the serotonin transporter gene for the outcome of a fear-exposure treatment. A discriminative fear conditioning paradigm was conducted in 159 adults highly fearful of spiders, dental surgeries or blood, injuries and injections. Participants were genotyped for the long (L) and short (S) allelic variant of the serotonin transporter gene linked polymorphic region (5HTTLPR) and treated with a highly standardized exposure-based one-session treatment. Participants' subjective fear was assessed during experimental fear conditioning and extinction. Furthermore, subjective phobic fear was assessed at pre-, post and at 7 months follow-up treatment assessment. A threat-biased contingency learning pattern characterized by exaggerated fear responses to the CS− was associated with larger initial subjective fear reduction immediately following the large-group treatment, p = .03. There were no learning pattern-associated differences in subjective fear at 7-month follow-up. The odds of homozygous s-allele carriers to display a threat-biased contingency learning pattern were 3.85 times larger compared to l-allele carriers, p = .01. Fear-recovery in homozygous S-allele carriers at follow-up assessment, p = .01, emerged regardless of the experimental fear acquisition pattern. Our results suggest the homozygous S-allele carriers are biologically biased towards ignoring safety signals in threat-related situations. Short-term, this response pattern might be positively related to the outcome of exposure treatments, potentially due to increased responding to safe context conditions or a stronger violation of threat expectancies. However, alterations in inhibiting the response to cues formerly signalling threat evidenced for S-allele carriers can have negative impact on exposure success.

Language lateralization is one of the most prominent examples of functional hemispheric asymmetries. Previous studies indicate a significant contribution of factors not related to DNA sequence variation on the development of language lateralization, but the molecular processes underlying this relation are unclear. The Brandler-Paracchini model of hemispheric asymmetries assumes that genes involved in the establishment of ciliogenesis and bodily asymmetries also affect functional hemispheric asymmetries. Thus, genes implicated in this model represent a key target for epigenetic modulation of language lateralization. Here, we analyzed DNA methylation in the KIAA0319 (a gene involved in dyslexia and ciliogenesis) promoter region to investigate whether epigenetic markers of language lateralization can be identified in non-neuronal tissue. We found sex-specific effects of DNA methylation in single CpG sites on language lateralization in the forced-left (FL) and the forced-right (FR), but not on language lateralization in the non-forced (NF) condition of the dichotic listening task. These findings suggest that DNA methylation patterns in the KIAA0319 promoter region might be associated with cognitive control processes that are necessary to perform well in the forced-attention conditions. Furthermore, the assumption of an association between genes involved in ciliogenesis and the ontogenesis of functional hemispheric asymmetries is supported.

Background: Methodological problems of existing research, such as the application of unstandardized treatments in heterogeneous samples, has hampered clear conclusions about the extent and direction to which allelic variation of the serotonin transporter gene-linked polymorphic region (5- HTTLPR) is associated with a differential response to psychological treatment. The present study aimed to investigate the effects of the 5-HTTLPR genotype on treatment outcome under highly standardized environmental conditions. Methods: We treated 222 medication-free adults highly fearful of spiders, dental surgeries or blood, injuries and injections with a highly standardized exposure-based 1-session treatment and genotyped them for the 5-HTTLPR. Participants' subjective fear was assessed before, immediately after treatment and at 7 months of follow-up. Results: There were no differences between 5-HTTLPR genotypes in treatment outcome effects at the immediate posttreatment assessment. However, we observed a highly significant genotype × treatment effect (p = 0.004) at the 7-month follow-up. Fear levels of homozygous S allele carriers differed from those heterozygous (p = 0.026) and homozygous (p = 0.012) for the L allele. Compared to posttreatment assessment, LL allele carriers exhibited a further fear decrease at the follow-up assessment. In contrast, SS allele carriers displayed a strong return of fear. Conclusions: Results suggest that genetic variation of the serotonin transporter is associated with differential stability of inhibitory learning processes, potentially reflecting heightened susceptibility for context-related processes that facilitate a return of fear in S allele carriers. If replicated, results suggest the 5-HTTLPR might represent a biomarker for the long-term outcome of brief exposure-based fear treatments and might inform genotype-based selection of psychotherapeutic interventions.

Hypothalamic-pituitary-adrenal (HPA) axis function is disrupted in institutionally-deprived children - reduced morning cortisol, flattened diurnal slope and blunted reactivity persist even after successful adoption into positive family environments. Here we test whether such effects persist into adulthood. Cortisol release across the day (sampled at awakening, 30 and 45min later, and at four points across the day) was investigated in young adult adoptees who had lived in severe deprivation for up to 43 months in early childhood in Ceaușescu's Romanian orphanages and a comparison group of non-deprived UK adoptees (Total N=57; mean age=24±0.9years). The mediating role of cortisol levels on adult mental health was examined using data from standardized clinical assessments. Cortisol profiles were disrupted in the Romanian adoptees who experienced more than 6 months deprivation marked by a striking absence of the cortisol awakening response (CAR) and a significantly flatter cortisol curve until 1h 15min after awakening. Whereas institutional deprivation was associated with both cortisol secretion and emergence of emotional problems in young adulthood, path analysis revealed no evidence for a mediating role of CAR disruption in the sub-sample studied here. The results are in line with findings of HPA axis hypo-functionality following early adverse experience and provide strong evidence for long-term programming effects of HPA axis function through experience of institutional deprivation.

Handedness is the most pronounced behavioral asymmetry in humans. Genome-wide association studies have largely failed to identify genetic loci associated with phenotypic variance in handedness, supporting the idea that the trait is determined by a multitude of small, possibly interacting genetic and non-genetic influences. However, these studies typically are not capable of detecting influences of rare mutations on handedness. Here, we used whole exome sequencing in a Turkish family with history of consanguinity and overrepresentation of left-handedness and performed quantitative trait analysis with handedness lateralization quotient as a phenotype. While rare variants on different loci showed significant association with the phenotype, none was functionally relevant for handedness. This finding was further confirmed by gene ontology group analysis. Taken together, our results add further evidence to the suggestion that there is no major gene or mutation that causes left-handedness.

Lateralization is a fundamental principle of nervous system organization but its molecular determinants are mostly unknown. In humans, asymmetric gene expression in the fetal cortex has been suggested as the molecular basis of handedness. However, human fetuses already show considerable asymmetries in arm movements before the motor cortex is functionally linked to the spinal cord, making it more likely that spinal gene expression asymmetries form the molecular basis of handedness. We analyzed genome-wide mRNA expression and DNA methylation in cervical and anterior thoracal spinal cord segments of five human fetuses and show development-dependent gene expression asymmetries. These gene expression asymmetries were epigenetically regulated by miRNA expression asymmetries in the TGF-β signaling pathway and lateralized methylation of CpG islands. Our findings suggest that molecular mechanisms for epigenetic regulation within the spinal cord constitute the starting point for handedness, implying a fundamental shift in our understanding of the ontogenesis of hemispheric asymmetries in humans. DOI: http://dx.doi.org/10.7554/eLife.22784.001

Background Clear recognition of the damaging effects of poverty on early childhood development has fueled an interest in interventions aimed at mitigating these harmful consequences. Psychosocial interventions aimed at alleviating the negative impacts of poverty on children are frequently shown to be of benefit, but effect sizes are typically small to moderate. However, averaging outcomes over an entire sample, as is typically done, could underestimate efficacy because weaker effects on less susceptible individuals would dilute estimation of effects on those more disposed to respond. This study investigates whether a genetic polymorphism of the serotonin transporter gene moderates susceptibility to a psychosocial intervention. Methods and findings We reanalyzed data from a randomized controlled trial of a home-visiting program delivered by community health workers in a black, isiXhosa-speaking population in Khayelitsha, South Africa. The intervention, designed to enhance maternal-infant attachment, began in the third trimester and continued until 6 mo postpartum. Implemented between April 1999 and February 2003, the intervention comprised 16 home visits delivered to 220 mother–infant dyads by specially trained community health workers. A control group of 229 mother–infant dyads did not receive the intervention. Security of maternal-infant attachment was the main outcome measured at infant age 18 mo. Compared to controls, infants in the intervention group were significantly more likely to be securely attached to their primary caregiver (odds ratio [OR] = 1.7, p = 0.029, 95% CI [1.06, 2.76], d = 0.29). After the trial, 162 intervention and 172 control group children were reenrolled in a follow-up study at 13 y of age (December 2012–June 2014). At this time, DNA collected from 279 children (134 intervention and 145 control) was genotyped for a common serotonin transporter polymorphism. There were both genetic data and attachment security data for 220 children (110 intervention and 110 control), of whom 40% (44 intervention and 45 control) carried at least one short allele of the serotonin transporter gene. For these 220 individuals, carrying at least one short allele of the serotonin transporter gene was associated with a 26% higher rate of attachment security relative to controls (OR = 3.86, p = 0.008, 95% CI [1.42, 10.51], d = 0.75), whereas there was a negligible (1%) difference in security between intervention and control group individuals carrying only the long allele (OR = 0.95, p = 0.89, 95% CI [0.45, 2.01], d = 0.03). Expressed in terms of absolute risk, for those with the short allele, the probability of secure attachment being observed in the intervention group was 84% (95% CI [73%, 95%]), compared to 58% (95% CI [43%, 72%]) in the control group. For those with two copies of the long allele, 70% (95% CI [59%, 81%]) were secure in the intervention group, compared to 71% (95% CI [60%, 82%]) of infants in the control group. Controlling for sex, maternal genotype, and indices of socioeconomic adversity (housing, employment, education, electricity, water) did not change these results. A limitation of this study is that we were only able to reenroll 49% of the original sample randomized to the intervention and control conditions. Attribution of the primary outcome to causal effects of intervention in the present subsample should therefore be treated with caution. Conclusions When infant genotype for serotonin transporter polymorphism was taken into account, the effect size of a maternal-infant attachment intervention targeting impoverished pregnant women increased more than 2.5-fold when only short allele carriers were considered (from d = 0.29 for all individuals irrespective of genotype to d = 0.75) and decreased 10-fold when only those carrying two copies of the long allele were considered (from d = 0.29 for all individuals to d = 0.03). Genetic differential susceptibility means that averaging across all participants is a misleading index of efficacy. The study raises questions about how policy-makers deal with the challenge of balancing equity (equal treatment for all) and efficacy (treating only those whose genes render them likely to benefit) when implementing psychosocial interventions. Trial Registration Current Controlled Trials ISRCTN25664149, In light of genetic information Barak Morgan and colleagues re-analyze data from a randomized controlled trial to explore the genetic susceptibility to a psychosocial intervention., Author summary Why was this study done? It has been shown that individuals with the short form of a gene involved in nerve signaling in the brain are generally sensitive, or “susceptible,” to psychosocial interventions (i.e., they benefit), whereas individuals with the long form of the gene are insensitive, or “nonsusceptible,” deriving little benefit from the same intervention. This study was conducted to investigate whether such a gene × intervention interaction was present in a previously conducted randomized controlled home-visiting intervention trial designed to increase levels of secure maternal-infant attachment at 18 mo of age in a population in South Africa. What did the researchers do and find? Genotyping revealed that 40% of the study sample (n = 89) carried at least one short allele of the serotonin transporter gene, while 60% of the sample (n = 131) carried two long alleles of this gene. We reanalyzed the original maternal-infant attachment results and found that the increase in secure attachment found for the intervention in the original trial (odds ratio = 1.7, effect size d = 0.29) was almost entirely attributable to children with the short form of the gene (odds ratio = 3.86, effect size d = 0.75). For children not carrying the short allele, there was no significant increase in secure attachment with the intervention (odds ratio = 0.95, effect size d = 0.03). Children carrying the short form of the gene whose mothers received the intervention were 3.86 times more likely to be securely attached at 18 mo (84% were secure) than children carrying the short form whose mothers did not receive the intervention (58% were secure). Among children without the short form, the number who were securely attached did not differ based on whether their mothers received the intervention (71% were secure) or not (70% were secure). What do these findings mean? These results indicate the importance of genetic differences when considering the efficacy of psychosocial interventions aimed at improving developmental outcomes in children living in the context of socioeconomic adversity. The findings also raise complex questions regarding spending limited resources implementing costly interventions on individuals who may not benefit because of their genetic makeup and who may comprise the majority of the population (60% in this case), but where these same interventions may nevertheless confer large benefit for a subgroup of genetically susceptible individuals (40% in this case).

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.

Research across species has shown that the neuropeptide oxytocin plays a key role in the regulation of social cognition and behavior. It is important for attachment, social exploration, and social recognition, as well as anxiety and stress-related behaviors. Based on oxytocin administration studies and measurements of peripheral oxytocin levels, it has been suggested that signaling of oxytocin is impaired in mental disorders associated with social deficits, including autism, borderline personality disorder, and social anxiety disorder. There are several factors influencing interindividual differences in social-cognitive abilities and differences in the susceptibility to psychiatric disorders, including variability in genes involved in oxytocin signaling. In addition to sequence variation, interindividual differences might in part be explained by variation in epigenetic processes influencing gene expression. Here, we provide an overview of the functional organization and epigenetic regulation of the murine and human oxytocin receptor gene.

The practice of doping threatens fair competition in sports. With the very recent reports on successful gene therapies for several diseases, the likelihood for abuse of gene transfer techniques in elite sports is rapidly increasing. It is therefore very important to develop valid detection techniques for transgenic DNA (tDNA) with ultimate sensitivity and specificity. To date, three slightly different procedures have been reported to reliably detect tDNA with sufficiently high sensitivity. Two utilize a real-time PCR-based approach and one uses a primer-internal, intron-spanning PCR approach (spiPCR). The specificity and sensitivity of these techniques, however, is still a matter of debate. Based on spiPCR, here we present a novel one-tube nested PCR approach that minimizes the chances for cross-contamination and shows increased sensitivity compared to non-nested PCR techniques. To further reduce the occurrence of false-positives based on cross-contamination, a multi-functional 19bp extended erythropoietin standard (EPO) was cloned which can be easily differentiated from transgenic EPO DNA (tEPO) and can be used as an internal or external positive control in PCR-based applications. We found that one-tube nested PCR is superior in terms of sensitivity and specificity compared to conventional PCR, and shows similar sensitivity compared to real-time based PCR assays. Although it did not reach sensitivity of spiPCR, the one-tube nested PCR technique described here is less laborious, less expensive and much faster than spiPCR. This technique might therefore be useful as a pre-screening tool for gene doping in the future. Copyright © 2012 John Wiley & Sons, Ltd.

Gene doping--or the abuse of gene therapy--will continue to threaten the sports world. History has shown that progress in medical research is likely to be abused in order to enhance human performance. In this review, we critically discuss the progress and the risks associated with the field of erythropoietin (EPO) gene therapy and its applicability to EPO gene doping. We present typical vector systems that are employed in ex vivo and in vivo gene therapy trials. Due to associated risks, gene doping is not a feasible alternative to conventional EPO or blood doping at this time. Nevertheless, it is well described that about half of the elite athlete population is in principle willing to risk its health to gain a competitive advantage. This includes the use of technologies that lack safety approval. Sophisticated detection approaches are a prerequisite for prevention of unapproved and uncontrolled use of gene therapy technology. In this review, we present current detection approaches for EPO gene doping, with a focus on blood-based direct and indirect approaches. Gene doping is detectable in principle, and recent DNA-based detection strategies enable long-term detection of transgenic DNA (tDNA) following in vivo gene transfer.

Over the course of the past decade, technical progress has enabled scientists to investigate genome-wide RNA ex- pression using microarray platforms. This transcriptomic approach represents a promising tool for the discovery of basic gene expression patterns and for identification of cellular signalling pathways under various conditions. Since doping substances have been shown to influence mRNA expression, it has been suggested that these changes can be detected by screening the blood transcriptome. In this review, we critically discuss the potential but also the pitfalls of this application as a tool in doping research. Transcriptomic approaches were considered to potentially provide researchers with a unique gene expres- sion signature or with a specific biomarker for various physiological and pathophysiological conditions. Since transcriptomic approaches are considerably prone to biological and technical confounding factors that act on study subjects or samples, very strict guidelines for the use of transcriptomics in human study subjects have been developed. Typical field conditions associ- ated with doping controls limit the feasibility of following these strict guidelines as there are too many variables counteracting a standardized procedure. After almost a decade of research using transcriptomic tools, it still remains a matter of future techno- logical progress to identify the ultimate biomarker using technologies and/or methodologies that are sufficiently robust against typical biological and technical bias and that are valid in a court of law. Copyright © 2011 John Wiley & Sons, Ltd.