Mechanism of hydroxychloroquine in the treatment of obstetric antiphospholipid syndrome by inhibiting NETs-induced trophoblast pyroptosis.

Neutrophil extracellular traps (NETs) play a crucial role in the adverse pregnancy outcomes associated with obstetric antiphospholipid syndrome (OAPS). However, the mechanism by which NETs lead to placental dysfunction is unclear. Hydroxychloroquine (HCQ) represents a first-line therapy for refractory OAPS, yet data on its pharmacological effects are limited. Therefore, we investigated the protective function of HCQ and the pathological process of NETs in OAPS in relation to cell pyroptosis. The anti-β2GPI antibody induced significant NETs formation. Antiphospholipid antibody-induced NETs (aPL-NETs) induced significant in vivo and in vitro trophoblast pyroptosis and inflammatory cytokine release, which were improved following the administration of NET degradation agent DNaseI. Furthermore, mitochondrial reactive oxygen species were involved in aPL-NETs-induced trophoblast pyroptosis. HCQ significantly alleviated the trophoblast pyroptosis induced by aPL-NETs. Mechanistically, HCQ inhibited the abnormal activation of MAPK and NF-κB signaling pathways in trophoblast cells and promoted the expression of antioxidants. Our findings provide novel insights into the pyroptotic role of NETs in OAPS pathogenesis and reveal the potential therapeutic targets of HCQ, confirming its pharmacological effects. Furthermore, we suggest that oxidative stress is an important mediator of NETs involvement in OAPS placental dysfunction, providing theoretical support for follow-up studies.