Roles of endoplasmic reticulum stress, apoptosis and autophagy in 2,2′,4,4′-tetrabromodiphenyl ether-induced rat ovarian injury

Endocrine disruptor 2,2′,4,4′-tetrabromodiphenylether (PBDE-47) can harm the female reproductive system. Recent studies showed that PBDE-47 neurotoxicity is associated with endoplasmic reticulum stress (ERS); however, the role of ERS in PBDE-47-induced ovarian injury is unclear. New-born female Sprague-Dawley rats were orally exposed to PBDE-47 (1, 5, or 10 mg/kg bw) on postnatal day 10. An additional 10 mg/kg bw PBDE-47 group was given the ERS inhibitor 4-PBA intraperitoneally for three weeks beginning on postnatal day 8. At 2 months of age, PBDE-47 exposure significantly reduced the ovarian coefficients, increased the expression of ERS and autophagy markers, including GRP78, IRE1, Caspase-12, Beclin1, LC3 and P62. In the 10 mg/kg bw PBDE-47 group, PARP and Caspase-3 were markedly activated, indicative of apoptosis. These were accompanied by histopathological damage. Intriguingly, 4-PBA attenuated all these effects. Thus, these results suggest that ERS plays a vital role in PBDE-47-induced ovarian injury by regulating autophagy and apoptosis.