Gene networks specific for innate immunity define post-traumatic stress disorder.

Area of Science:

• Genomics
• Immunology
• Psychiatry

Background:

• Molecular mechanisms underlying Post-Traumatic Stress Disorder (PTSD) are not fully understood.
• Previous studies used limited, cross-sectional approaches, missing a systems-level view of gene behavior.

Purpose of the Study:

• To apply an unsupervised gene-network approach to prospective transcriptomic data for identifying molecular signatures of PTSD.
• To investigate gene expression patterns pre- and post-deployment in U.S. Marines to understand PTSD development and resilience.

Main Methods:

• Whole-transcriptome RNA-Seq was performed on peripheral blood leukocytes from U.S. Marines (N=188) pre- and post-deployment.
• Unsupervised co-expression network analysis identified gene modules associated with PTSD.
• Findings were validated in an independent cohort (N=96).

Main Results:

• A co-expression module, over-expressed both pre- and post-deployment, showed signatures of PTSD development, enriched for innate immune and Type-I/II interferon signaling pathways.
• This immune-related module was replicated in an independent dataset, confirming its role in PTSD pathophysiology.
• A second module, associated with trauma exposure, indicated PTSD resilience signatures and over-expressed genes in hemostasis and wound healing, suggesting chronic stress impairs wound repair.

Conclusions:

• Innate immune and interferon signaling pathways are implicated in the causal pathophysiology of PTSD.
• The hemostatic system may serve as a clinical indicator for chronic stress and its impact on wound healing.
• These findings offer potential for early PTSD detection and preventative interventions.