Chronic Stress Destabilizes Ectoplasmic Specialization Dynamics in the Rat Testis via Downregulating the Focal Adhesion Kinase-Associated Protein Complex.

Prolonged stress adversely affects male reproductive health, with infertility affecting millions of couples worldwide due to lifestyle and mental health factors. Chronic unpredictable stress (CUS) has been shown to induce testicular dysfunction via blood-testis barrier (BTB) disruption. The BTB, maintained by ectoplasmic specialisations (ES), is regulated by β1-integrin and phosphorylated focal adhesion kinase (FAK)-associated proteins. Still, the impact of prolonged stress on these regulators has not been fully explored. This study investigated CUS-induced testicular damage over extended durations. Sprague-Dawley rats were exposed to CUS for 8, 14, or 18 weeks, with respective controls (n = 6/group). Depressive behaviour was confirmed by increased anhedonia, anxiety-like behaviour, and corticosterone levels, alongside decreased exploratory activity. Sperm count, motility, morphology, and chromatin integrity were significantly reduced, particularly in the 14- and 18-week CUS groups. FSH, LH, and testosterone levels were also decreased in all CUS-exposed groups. Western blot analysis revealed marked reductions in BTB markers, 11β-HSD, and irisin, with increased testicular apoptosis. Disruption of pFAK (Tyr397) signaling destabilized the apical ES, while reduced pFAK (Tyr407) expression and decreased levels of p-Akt, p-mTOR, and phospho-p70S6 kinase loosened tight junctions. Overall, prolonged CUS exerted cumulative adverse effects on male reproductive function, with both the magnitude and duration of stress critically influencing severity. These findings elucidate the mechanism by which chronic stress compromises BTB integrity and impairs spermatogenesis, highlighting the progressive nature of stress-induced reproductive dysfunction.