Pre-eclampsia related TLR2/4 signaling activates NOX2/4 to induce oxidative stress and ferroptosis in trophoblasts

Abstract Pre-eclampsia (PE) is a pregnancy-related complication which is closely related to the malfunction of trophoblasts. Oxidative stress and ferroptosis have been recognized as detrimental factors linked with trophoblast dysfunction. Nevertheless, the signaling pathways dictating the oxidative stress and ferroptosis in placental tissues of PE patients are unclear. In this study, we investigated the roles of Toll-like receptor (TLR) signaling in PE-induced ferroptosis in the placenta tissues and explored the therapeutic potential of targeting TLR signaling in the animal model of PE. The expression levels of TLR2/4 and MAPK signaling activation were compared in the placental tissues between healthy controls and PE patients. The role of TLR2/4 and MAPK signaling in ischemia-induced ferroptosis was investigated in the trophoblasts with hypoxia/re-oxygenation (H/R) induction. TLR and NADPH Oxidase (NOX) inhibitors were applied in the rat model of PE to evaluate the therapeutic potential. We found the upregulation of TLR2/4 and the over-activation of MAPK signaling in the placental tissues of PE patients and in the H/R induced trophoblasts. Inhibiting TLR2/4 expression reduced MAPK signaling and improved trophoblast functions after H/R induction. TLR2/4 signaling dependent NOX2 and NOX4 upregulation contributed to the oxidative stress and ferroptosis in trophoblasts upon H/R induction. In the rat model of PE, inhibiting TLR2/4 and NOX activity prevented ferroptotic events in the placental tissues. Collectively, our findings suggest that TLR2/4-dependent oxidative stress and ferroptosis may undermine the function of trophoblasts in the PE placenta, and targeting TLR signaling-mediated ferroptosis could serve as an intervention strategy of PE.