Tetrabromobisphenol A-bis(2,3-dibromopropyl ether) impairs Postnatal Testis Development in Mice: The Microtubule Cytoskeleton as a Sensitive Target.

Abstract

Tetrabromobisphenol A-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE), a widely used flame retardant, has been frequently detected in various environmental compartments, but its health hazard remains largely unknown. Here, we investigated the adverse effects of TBBPA-BDBPE (50 and 1000 μg/kg/day) on postnatal testis development in CD-1 mice and the underlying mechanism. Following the first week of maternal exposure, neonatal mice in the high-dose group exhibited reduced seminiferous tubule area, fewer Sertoli cells and germ cells, and damaged microtubules in Sertoli cells; even microtubule damage was also observed in the low-dose group. When exposure extended to adulthood, male offspring in the high-dose group presented more remarkable alterations in reproductive parameters, including reduced sperm count; in the low-dose group, microtubule damage was also observable, along with blood-testis barrier impairment. Further molecular docking analysis and tubulin polymerization assay indicated that TBBPA-BDBPE could interact with tubulin and disrupt its polymerization. Moreover, we observed attenuated microtubules in mouse Sertoli cells in vitro (TM4) following TBBPA-BDBPE treatment, suggesting that TBBPA-BDBPE impaired testis development possibly by interfering with tubulin dynamics. This study not only highlights the male reproductive hazard of TBBPA-BDBPE but also greatly improved the understanding of the molecular mechanism for male reproductive toxicity of chemicals.