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Background Women with antiphospholipid syndrome (APS) or antiphospholipid antibodies (aPLs) are at high risk for obstetric complications, including recurrent pregnancy loss (RPL). However, effective treatments for RPL are lacking. Objective This study aimed to reveal the function and underlying mechanism of hyperoside (Hyp) in RPL associated with antiphospholipid antibodies (aCLs). Methods The pregnant rats ( N = 24) were divided randomly into four groups: normal human-IgG (NH-IgG); aCL-pregnancy loss (aCL-PL); aCL-PL + Hyp (40 mg/kg/day); aCL-PL + low molecular weight heparin (LMWH, 525 μg/kg/day). HTR‐8 cells were treated with 80 μg/mL aCL to establish the cell models of miscarriage. Results In pregnant rats, aCL-IgG injection raised the abortion rate of embryos, while Hyp treatment inhibited the effects. Additionally, Hyp inhibited the platelet activation and uteroplacental insufficiency caused by aCL. In vivo and in vitro experiments further suggested that Hyp suppressed aCL-induced inflammation and apoptosis by downregulating NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-related factors and decreasing apoptotic rates. After aCL administration, Hyp therapy downregulated the expression of purinergic ligand-gated ion channel 7 (P2X7), which is reported to induce cytokine release and apoptosis. Furthermore, we found that the treatment of 3′-O-(4-Benzoyl) benzoyl-ATP (BzATP, an agonist of the P2X7 receptor) reversed the inhibitory effects of Hyp on cell function. Conclusions Hyp exerts protective effects on aCL-induced pregnancy loss by preventing platelet activation-mediated P2X7/NLRP3 pathway. Therefore, Hyp may provide a feasible pharmaceutical strategy for the treatment of RPL.

Anticardiolipin antibody (aCL), an important characterization of antiphospholipid syndrome, shows an intense association with vascular endothelial injury. Hyperoside is a flavonoid extracted from medicinal plants traditionally used in Chinese medicines, displaying anti-inflammatory, anti-cancer, and anti-oxidative properties in various diseases. Recent studies have shifted the focus on the protective effects of hyperoside on vascular endothelial injury. However, little is known about the mechanisms involved. In the present study, we investigated the effect of hyperoside on aCL-induced injury of human umbilical vein endothelial cells (HUVECs) in vitro. Our data illustrated that aCL induced HUVEC injury via inhibiting autophagy. Hyperoside reduced aCL-induced secretion of proinflammatory cytokines IL-1β and IL-8 and endothelial adhesion cytokines TF, ICAM1, and VCAM1 in HUVECs. Additionally, hyperoside activated autophagy and suppressed the mTOR/S6K and TLR4/Myd88/NF-κB signaling transduction pathways in aCL-induced HUVECs. To the best of our knowledge, this is the first study to investigate the effect of hyperoside on aCL-induced injury, as well as offer insights into the involved mechanisms, which is of great significance for the treatment of antiphospholipid syndrome.

Aims Recurrent pregnancy loss (RPL) is one of the most common obstetrical diseases, which is a manifestation of antiphospholipid syndrome (APS) with no effective therapy methods. Autophagy and inflammatory responses both play an important role in the pathogenesis of RPL and hyperoside has been demonstrated to have multifarious bioactivities including enhancing autophagy and anti-inflammation. This study aims to investigate the effect of hyperoside on anticardiolipin (aCL)-IgG fractions-induced pregnancy loss. Main methods In the present study, the effect of hyperoside was evaluated in a rat model of pregnancy loss induced by aCL-IgG fractions isolated from serum of APS patients. The fetuses were counted and the placentas were weighted and the protein expressions of inflammation and autophagy were measured by western blot analysis. Key findings Treatment with hyperoside (40 mg/kg) improved pregnancy outcome manifest as increasing the weight of fetuses and decreasing the fetal resorption rate. In addition, hyperoside treatment downregulated the expressions of phosphorylated mammalian target of rapamycin (mTOR), phosphorylated p70S6 Kinase (S6K) and inhibited the expressions of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and NF-kB p-p65 in pregnancy loss animal models. Significance Hyperoside attenuated pregnancy loss through regulating mTOR/S6K and TLR4/MyD88/NF-kB signaling pathways, which may provide a potential drug candidate for recurrent pregnancy loss therapy.