Supplementary Material for: Cross-species convergence of brain transcriptomic and epigenomic findings in posttraumatic stress disorder: A systematic review

Introduction: Posttraumatic stress disorder (PTSD) is a complex multifactorial disorder influenced by the interaction of genetic and environmental factors. Analyses of epigenomic and transcriptomic modifications may help to dissect the biological factors underlying the gene-environment interplay in PTSD. To date, most human PTSD epigenetics studies have used peripheral tissue, and these findings have complex and poorly-understood relationships to brain alterations. Studies examining brain tissue may help characterize the brain-specific transcriptomic and epigenomic profiles of PTSD. In this review, we compiled and integrate brain-specific molecular findings of PTSD from humans and animals. Methods: A systematic literature search according to the PRISMA criteria was performed to identify transcriptomic and epigenomic studies of PTSD, focusing on brain tissue from human postmortem samples or animal-stress paradigms. Results: Gene- and pathway-level convergence analyses revealed PTSD-dysregulated genes and biological pathways across brain regions and species. A total of 243 genes converged across species, 17 of them significantly enriched for PTSD. Chemical-synaptic transmission and signaling by G-protein-coupled receptors (GPCRs) were consistently enriched in across -omics and species. Discussion: Our findings point out dysregulated genes highly replicated across PTSD studies in humans and animal models and suggest a potential role for the corticotropin-releasing hormone/orexin pathway in PTSD’s pathophysiology. Further, we highlight current knowledge gaps and limitations and recommend future directions to address them.