Project description:Early life social experiences are believed to confer persistent effects on individual’s biology and subsequent functioning and health. Using a diverse, longitudinal community sample of 178 children, we show that three different types of early life social experience: family income, parental education, and family psychosocial adversity, each predict DNA methylation within buccal epithelial cells. Each predictor was significantly associated with DNA methylation within a unique set of genomic CpG sites, with income showing the greatest number of associations. Findings were independently verified using pyrosequencing. Our results provide evidence for longitudinal associations between early life social environment and variation in DNA methylation during childhood, after adjusting for genetic ancestry and self-reported ethnic minority status. Gene ontology analyses of top, differentially methylated CpG sites point to genes serving immune and developmental regulation functions, suggesting potential pathways for the biological embedding of early life stress and its association with later development and health.
Project description:Epigenetics is emerging as an attractive mechanism to explain the persistent genomic embedding of early-life experiences. Tightly linked to chromatin, which packages DNA into chromosomes, epigenetic marks primarily serve to regulate the activity of genes. DNA methylation is the most accessible and characterized component of the many chromatin marks that constitute the epigenome, making it an ideal target for epigenetic studies in human populations. Here, using peripheral blood mononuclear cells collected from a community-based cohort stratified for early-life socioeconomic status, we measured DNA methylation in the promoter regions of more than 14,000 human genes. Using this approach, we broadly assessed and characterized epigenetic variation, identified some of the factors that sculpt the epigenome, and determined its functional relation to gene expression.We found that the leukocyte composition of peripheral blood covaried with patterns of DNA methylation at many sites, as did demographic factors, such as sex, age, and ethnicity. Furthermore, psychosocial factors, such as perceived stress, and cortisol output were associated with DNA methylation, as was early-life socioeconomic status. Interestingly, we determined that DNA methylation was strongly correlated to the ex vivo inflammatory response of peripheral blood mononuclear cells to stimulation with microbial products that engage Toll-like receptors. In contrast, our work found limited effects of DNA methylation marks on the expression of associated genes across individuals, suggesting a more complex relationship than anticipated This cohort consist of genomic DNA extracted from 94 PBMC DNA samples, bisulphite converted and hybridized, along with 5 technical replicates to the Illumina Infinium HumanMethylation27 Beadchip v1.2 for genome wide DNA methylation profiling.
Project description:Epigenetics is emerging as an attractive mechanism to explain the persistent genomic embedding of early-life experiences. Tightly linked to chromatin, which packages DNA into chromosomes, epigenetic marks primarily serve to regulate the activity of genes. DNA methylation is the most accessible and characterized component of the many chromatin marks that constitute the epigenome, making it an ideal target for epigenetic studies in human populations. Here, using peripheral blood mononuclear cells collected from a community-based cohort stratified for early-life socioeconomic status, we measured DNA methylation in the promoter regions of more than 14,000 human genes. Using this approach, we broadly assessed and characterized epigenetic variation, identified some of the factors that sculpt the epigenome, and determined its functional relation to gene expression.We found that the leukocyte composition of peripheral blood covaried with patterns of DNA methylation at many sites, as did demographic factors, such as sex, age, and ethnicity. Furthermore, psychosocial factors, such as perceived stress, and cortisol output were associated with DNA methylation, as was early-life socioeconomic status. Interestingly, we determined that DNA methylation was strongly correlated to the ex vivo inflammatory response of peripheral blood mononuclear cells to stimulation with microbial products that engage Toll-like receptors. In contrast, our work found limited effects of DNA methylation marks on the expression of associated genes across individuals, suggesting a more complex relationship than anticipated
Project description:The serotonin transporter (5-HTT) gene-linked polymorphic region has been suggested to play a modulatory role in mediating the effects of early-life stress on psychopathology rendering carriers of the low-expression short (s)-allele more vulnerable to environmental adversity in later life. Here we analyzed the effects of prenatal stress (PS), 5-Htt genotype, and an interactin of both on DNA methylation in the hippocampi of female C57BL/6 mice. Here, we applied Methylated DNA ImmunoPrecipitation (MeDIP) in a maternal restraint stress paradigm to perform a global promoter DNA methylation screen: Hippocampal DNA of wild type and 5-Htt +/- mice in stressed and control environments were analyzed to define genotype- (G) and environment-dependent (E) as well as GxE-interactive effects on promoter DNA methylation in the brain region, where marked effects were expected. MeDIP-based promoter DNA methylation screen
Project description:Research shows that children who are reared in households with low socioeconomic status are more vulnerable to heart disease, respiratory infection, and some cancers when they reach adulthood. This study conducted transcriptional profiling of PBMC in healthy adults who were low vs. high in early-life SES to explore the long-lasting genomic effects of early experience. Keywords: life stress, gene expression, inflammation, socioeconomic status Samples from 30 adults with low early-life SES and 30 adults with high early-life SES
Project description:Social anxiety disorder (SAD) is a psychiatric disorder characterized by extensive fear in social situations. Multiple genetic and environmental factors are known to contribute to its pathogenesis. One of the main environmental risk factors is early life adversity (ELA). Evidence is emerging that epigenetic mechanisms such as DNA methylation might play an important role in the biological mechanisms underlying SAD and ELA. To investigate the relationship between ELA, DNA methylation, and SAD, we performed an epigenome-wide association study for SAD and ELA examining DNA from whole blood of a cohort of 143 individuals using DNA methylation arrays. We identified two differentially methylated regions (DMRs) associated with SAD located within the genes SLC43A2 and TNXB. As this was the first epigenome-wide association study for SAD, it is worth noting that both genes have previously been associated with panic disorder. Further, we identified two DMRs associated with ELA within the SLC17A3 promoter region and the SIAH3 gene and several DMRs that were associated with the interaction of SAD and ELA. Of these, the regions within C2CD2L and MRPL28 showed the largest difference in DNA methylation. Lastly, we found that two DMRs were associated with both the severity of social anxiety and ELA, however, neither of them was found to mediate the contribution of ELA to SAD later in life. Future studies are needed to replicate our findings in independent cohorts and to investigate the biological pathways underlying these effects.
Project description:Prenatal adversity or stress can have long-term consequences on developmental trajec-tories and health outcomes. Although the biological mechanisms underlying these effects are poorly understood, epigenetic modifications, such as DNA methylation, have the potential to link early-life environments to alterations in physiological systems, with long-term functional impli-cations. We investigated the consequences of two prenatal insults, prenatal alcohol exposure (PAE) and food-related stress, on DNA methylation profiles of the rat brain during early devel-opment. As these insults can have sex-specific effects on biological outcomes, we analyzed epige-nome-wide DNA methylation patterns in prefrontal cortex, a key brain region involved in cogni-tion, executive function, and behavior, of both males and females. We found sex-dependent and sex-concordant influences of these insults on epigenetic patterns. These alterations occurred in genes and pathways related to brain development and immune function, suggesting that PAE and food-related stress may reprogram neurobiological/physiological systems partly through central epigenetic changes, and may do so in a sex-dependent manner. Such epigenetic changes may re-flect the sex-specific effects of prenatal insults on long-term functional and health outcomes and may have important implications for understanding possible mechanisms underlying fetal alco-hol spectrum disorder and other neurodevelopmental disorders.
Project description:Given the salient role of early-life adversity (ELA) and the resulting biological embedding in disease risk, there is a critical need to understand the mechanisms operating at multiple levels of analysis in order to promote effective clinical treatments and intervention efforts for survivors. An example for such an effort could be to utilize models of dynamic cellular markers as individual-level factors to account for variation in intervention response and clinical outcomes. Results of this study will lead to new knowledge about specific gene expression pathways in response to stress, and whether the response is moderated by previous exposure to early adversity, shorter telomere length (a marker of cellular aging) and self-report mental-health measures. Thus, the long-term effects of this study will advance our understanding on stress-related transcriptomic changes that play a downstream role in disease susceptibility and accelerated aging, with the goal of targeting specific pathways and genes for potential intervention studies and pharmacological treatments to reverse the effects of exposure to early adversity. For example, considering high failure rates for depression treatments, and in order to tailor individual interventions, identifying objective changes in stress-induced gene expression may help to predict intervention efficacy in clinical and non-clinical settings, as seen, for example, in breast and leukemia cancers. Thus, findings will have a range of impacts for basic science, intervention studies and clinical practice that will influence treatments to match the specific cellular processes operating within an individual.
Project description:Given the salient role of early-life adversity and the resulting biological embedding in disease risk, there is a critical need to understand the mechanisms operating at multiple levels of analysis in order to promote effective clinical treatments and intervention efforts for survivors. An example for such an effort could be to utilize models of dynamic cellular markers as individual-level factors to account for variation in intervention response and clinical outcomes. Results of this study will lead to new knowledge about specific gene expression pathways in response to stress, and whether the response is moderated by previous exposure to early adversity, shorter telomere length (a marker of cellular aging) and self-report mental-health measures. Thus, the long-term effects of this study will advance our understanding on stress-related transcriptomic changes that play a downstream role in disease susceptibility and accelerated aging, with the goal of targeting specific pathways and genes for potential intervention studies and pharmacological treatments to reverse the effects of exposure to early adversity. For example, considering high failure rates for depression treatments, and in order to tailor individual interventions, identifying objective changes in stress-induced gene expression may help to predict intervention efficacy in clinical and non-clinical settings, as seen, for example, in breast and leukemia cancers. Thus, findings will have a range of impacts for basic science, intervention studies and clinical practice that will influence treatments to match the specific cellular processes operating within an individual.