Epididymal glucocorticoid receptors promote intergenerational transmission of paternal stress

Paternal preconception exposures and insults, including stress, dietary challenge and drugs of abuse, can shape offspring health and disease risk outcomes, as evidenced from retrospective human studies and more recent animal models1-16. Mechanistic examination has implicated small noncoding RNA populations in sperm, including microRNA (miRs), as carriers of paternal environmental information that consequently influence offspring development15,17-21. However, the cellular mechanisms by which these paternal signals are relayed to sperm and how they may persist remain unknown. Here, using our previously established paternal stress mouse model we identify caput epididymal epithelial glucocorticoid receptors as crucial upstream mediators of long-lasting germ cell programming. We show that glucocorticoid treatment of caput epididymal epithelial cells results in increased glucocorticoid receptor levels and enduring changes to the miR content of secreted extracellular vesicles (EVs), or epididymosomes, known to interact with sperm and alter their RNA content22,23. Further, significant changes were detected in the caput epididymal histone code long after stress ended, both in vitro and in vivo, as a potential mechanism whereby stress programmed enduring changes to EV miRs. Genetic targeting to reduce caput epididymal epithelial-specific glucocorticoid receptors reversed stress-induced chromatin remodeling and promoted cellular resilience to paternal stress, ultimately rescuing transmission of a stress dysregulated offspring phenotype. Taken together, these studies identify glucocorticoid receptor regulation of EV miRs in the caput epididymis as a key contributor in the intergenerational transmission of paternal environmental stress experiences.