TDCIPP induces placental dysfunction and fetal growth restriction via oxidative stress-mediated PINK1/Parkin mitophagy.

Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate flame retardant increasingly linked to reproductive toxicity, yet its placental toxic mechanisms remain unclear. This study demonstrates that TDCIPP exposure disrupts placental homeostasis by inducing oxidative stress, which triggers excessive PINK1/Parkin-mediated mitophagy in both human trophoblasts (HTR-8/SVneo) and pregnant mice. Integrated network toxicology analysis predicted mitochondrial dysfunction and oxidative stress as central pathways, validated by upregulation of ATG5 and HMOX1, downregulation of SOD2, elevated ROS and mitochondrial superoxide, loss of mitochondrial membrane potential, and ultrastructural evidence of mitophagic vacuoles. TDCIPP activated the PINK1/Parkin pathway-evidenced by increased PINK1, Parkin, LC3-II/I, p62, reduced TOMM20, and enhanced Parkin-TOMM20 colocalization-while alternative mitophagy receptors FUNDC1 and BNIP3 remained unaffected. Mechanistically, oxidative stress acted upstream, as N-acetylcysteine (NAC) pretreatment suppressed ROS accumulation and PINK1/Parkin activation. Functionally, TDCIPP impaired trophoblast proliferation, induced apoptosis, and caused fetal growth restriction (FGR) in vivo. Notably, both genetic knockdown of Parkin in vitro and pharmacological inhibition of mitophagy with Mdivi-1 in vivo significantly alleviated trophoblast apoptosis and rescued placental and fetal weights. These findings establish that TDCIPP-induced placental injury is driven by an oxidative stress-PINK1/Parkin-mitophagy axis, revealing dysregulated mitophagy as a pivotal mechanism underlying TDCIPP-associated developmental toxicity and offering new insights into the reproductive risks of environmental flame retardant exposure.