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:Social anxiety disorder is characterized by a persistent and abnormal fear and avoidance of social situations, but available treatment options are rather unspecific. Using an established mouse social fear conditioning (SFC) paradigm, we profiled gene expression and chromatin alterations after acquisition and extinction of social fear within the septum, a brain region important for social fear and social behaviors. We validated coding and non-coding RNAs and found specific isoforms of the long non-coding RNA Meg3 to be regulated depending on the success of social fear extinction. In vivo knockdown of specific Meg3 isoforms in conditioned mice resulted in impaired social fear extinction, as revealed by lower social investigation levels at the end of the extinction training, accompanied with increased baseline activity of the PI3K/AKT signaling pathway. Using ATAC-Seq and CUT&RUN, we characterized alterations in chromatin level after social fear extinction and identified Auts2 and Dclk3 as potential targets of Meg3.
Project description:Social interactions are critical components for the survival of mammalian biology and evolution. Dysregulation of social behavior often leads to psychopathologies such as social anxiety disorder, which is characterized by an intense fear and avoidance of social situations. Using the social fear conditioning (SFC) paradigm, we analyzed expression levels of miR-132-3p and miR-124-3p within the septum, a brain region essential for social behavior and fear, after acquisition and extinction of social fear. Functional in vivo approaches using pharmacology, functional inhibition of miR-132-3p, viral miR-132 overexpression and shRNA-mediated knockdown of miR-132-3p within oxytocin receptor positive neurons confirmed septal miR-132-3p to be involved in social fear extinction and the oxytocin-mediated reversal of social fear. Moreover, Argonaute-RNA-co-immunoprecipitation-microarray analysis and further target mRNA quantification, depicted growth differentiation factor-5 (GDF-5) to be involved in miR-132-3p-mediated regulation of social fear extinction. Local application of GDF-5 resulted in impaired social fear extinction, an effect which seems to be mediated by miR-132-3p. In summary, we show that septal miR-132-3p is functionally involved in social fear extinction learning and oxytocin-mediated reversal of social fear.
Project description:Prospective epidemiological studies found that generalized anxiety disorder (GAD) can impair immune function and increase risk for cardiovascular disease or events. Mechanisms underlying the physiological reververations of anxiety, however, are still elusive. Hence, we aimed to investigate molecular processes mediating effects of anxiety on physical health using blood gene expression profiles of 546 community participants. Of these, 179 met the status of controls and 157 cases of anxiety.
Project description:Social anxiety disorder (SAD) is a psychiatric disorder characterized by severe fear in social situations and avoidance of these. Multiple genetic as well as environmental factors contribute to the etiopathology of SAD. One of the main risk factors for SAD is stress, especially during early periods of life (early life adversity; ELA). ELA leads to structural and regulatory alterations contributing to disease vulnerability. This includes the dysregulation of the immune response. However, the molecular link between ELA and the risk for SAD in adulthood remain largely unclear. Evidence is emerging that long-lasting changes of gene expression patterns play an important role in the biological mechanisms linking ELA and SAD. Therefore, we conducted a transcriptome study of SAD and ELA performing RNA sequencing in peripheral blood samples. Analyzing differential gene expression between individuals suffering from SAD with high or low levels of ELA and healthy individuals with high or low levels of ELA, 13 significantly differentially expressed genes (DEGs) were identified with respect to SAD whilst no significant differences in expression were identified with respect to ELA. The most significantly expressed gene was MAPK3 (p=0.003) being upregulated in the SAD group compared to control individuals. In contrary, weighted gene co-expression network analyses (WGCNA) identified only modules significantly associated with ELA (p≤0.05), not with SAD. Furthermore, analyzing interaction networks of the genes from the ELA-associated modules and the SAD-related MAPK3) revealed complex interactions of those genes. Gene functional enrichment analyses indicate a role of signal transduction pathways as well as inflammatory responses supporting an involvement of the immune system in the association of ELA and SAD. In conclusion, we did not identify a direct molecular link between ELA and adult SAD by transcriptional changes. However, our data indicate an indirect association of ELA and SAD mediated by the interaction of genes involved in immune-related signal transduction.
Project description:A cohort of adolescents and young adults took part in this longitudinal 5-year follow-up study. We selected four groups of subjects from the same community sample carefully paired by age and gender: (1) Typically Developing Adolescent (n=14); (2) Incident Anxiety Disorder (n=11); (3) Persistent Anxiety Disorder (n=14); (4) Remittent Anxiety Disorder (n=8).
Project description:Social stress mouse models were used to simulate human post-traumatic stress disorder (PTSD). C57B/6 mice exposed to SJL aggressor mice exhibited behaviors accepted as PTSD-in-mouse phenotype: 'frozen' motion, aggressor's barrier avoidance, startled jumping, and retarded locomotion. Transcripts in spleen, blood and hemi-brain of stressed and control C57B/6 mice were analyzed using Agilent's mouse genome-wide arrays. C57B6 mice were exposed to SJL aggressor mice for periods of 5 days and 10 days (6 hours each day) to induce anxiety/stress which parallels to PTSD in human. Organs, blood and brain regions were collected after 24 hours and 1.5 week of post 5 days social defeat period; and 24 hour and 6 weeks post 10 days social stress period.
Project description:Social stress mouse models were used to simulate human post-traumatic stress disorder (PTSD). C57B/6 mice exposed to SJL aggressor mice exhibited behaviors accepted as PTSD-in-mouse phenotype: 'frozen' motion, aggressor’s barrier avoidance, startled jumping, and retarded locomotion. Transcripts in hippocampus, amygdala, medial prefrontal cortex, ventral striatum (nucleus acumbens), septal region, corpus striatum, hemi-brain, blood, spleen and heart of stressed and control C57B/6 mice were analyzed using Agilent’s mouse genome-wide arrays. C57B6 mice were exposed to SJL aggressor mice for periods of 5 days and 10days (6 hours each day) to induce anxiety/stress which parallels to PTSD in human Organs, blood and brain regions were collected after 24 hours and 1.5 week of post 5 days social defeat period; and 24 hour and 6 weeks post 10 days social stress period.