Glucocorticoid-induced leucine zipper \u201cquantifies\u201d stressors and increases male susceptibility to PTSD

Maya A Lebow,Tanja Jovanovic,Michael Tsoory,Alicia K Smith,Dorin Holzman-Karniel,Bekh Bradley,Elisabeth B Binder,Divya Mehta,Shifra Ben-Dor,Shosh Gil,Mariana Schroeder,Alon Chen,Kerry J Ressler

doi:10.1038/s41398-019-0509-3

Abstract

Post-traumatic stress disorder (PTSD) selectively develops in some individuals exposed to a traumatic event. Genetic and epigenetic changes in glucocorticoid pathway sensitivity may be essential for understanding individual susceptibility to PTSD. This study focuses on PTSD markers in the glucocorticoid pathway, spotlighting glucocorticoid-induced leucine zipper (GILZ), a transcription factor encoded by the gene Tsc22d3 on the X chromosome. We propose that GILZ uniquely “quantifies” exposure to stressors experienced from late gestation to adulthood and that low levels of GILZ predispose individuals to PTSD in males only. GILZ mRNA and methylation were measured in 396 male and female human blood samples from the Grady Trauma Project cohort (exposed to multiple traumatic events). In mice, changes in glucocorticoid pathway genes were assessed following exposure to stressors at distinct time points: (i) CRF-induced prenatal stress (CRF-inducedPNS) with, or without, additional exposure to (ii) PTSD induction protocol in adulthood, which induces PTSD-like behaviors in a subset of mice. In humans, the number of traumatic events correlated negatively with GILZ mRNA levels and positively with % methylation of GILZ in males only. In male mice, we observed a threefold increase in the number of offspring exhibiting PTSD-like behaviors in those exposed to both CRF-inducedPNS and PTSD induction. This susceptibility was associated with reduced GILZ mRNA levels and epigenetic changes, not found in females. Furthermore, virus-mediated shRNA knockdown of amygdalar GILZ increased susceptibility to PTSD. Mouse and human data confirm that dramatic alterations in GILZ occur in those exposed to a stressor in early life, adulthood or both. Therefore, GILZ levels may help identify at-risk populations for PTSD prior to additional traumatic exposures.

Highlights

Post-traumatic stress disorder (PTSD) is a debilitating disorder that develops after exposure to a traumatic event[1,2,3] in 7–12% of the population who eventually develop long-term symptomology, with a higher prevalence in females than males[4]
A correlation was demonstrated between CAP score and reduced glucocorticoid-induced leucine zipper (GILZ) mRNA levels (P = 0.0160), Supplementary Fig. 1a)
Male PTSD patients have reduced circulating blood GILZ mRNA levels and increased methylation, which significantly correlated with the number of lifetime traumatic events experienced from childhood to adulthood

Summary

Introduction

Post-traumatic stress disorder (PTSD) is a debilitating disorder that develops after exposure to a traumatic event[1,2,3] in 7–12% of the population who eventually develop long-term symptomology, with a higher prevalence in females than males[4]. Experiment 2: CRF-inducedPNS in late gestation increases the likelihood to exhibit PTSD-like behaviors following exposure to adulthood trauma in male mice

Results

Conclusion