Epidemiological studies have demonstrated that fine particulate matter (PM2.5) is associated with adverse obstetric and postnatal metabolic health outcomes, but the mechanism remains unclear. This study aimed to investigate the toxicological pathways by which PM2.5 damaged placental trophoblasts in vivo and in vitro. We confirmed that PM2.5 induced adverse gestational outcomes such as increased fetal mortality rates, decreased fetal numbers and weight, damaged placental structure, and increased apoptosis of trophoblasts. Additionally, PM2.5 induced dysfunction of the trophoblast cell line HTR8/SVneo, including in its proliferation, apoptosis, invasion, migration and angiogenesis. Moreover, we comprehensively analyzed the transcriptional landscape of HTR8/SVneo cells exposed to PM2.5 through RNA-Seq and observed that PM2.5 triggered overexpression of pathways involved in oxidative stress and mitochondrial apoptosis to damage HTR8/SVneo cell biological functions through CYP1A1. Mechanistically, PM2.5 stimulated KLF9, a transcription factor identified as binding to CYP1A1 promoter region, which further modulated the CYP1A1-driven downstream phenotypes. Together, this study demonstrated that the KLF9/CYP1A1 axis played a crucial role in the toxic progression of PM2.5 induced adverse pregnancy outcomes, suggesting adverse effects of environmental pollution on pregnant females and putative targeted therapeutic strategies.

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disease mediated by antiphospholipid antibodies (aPL), characterized by miscarriage, pre-mature birth caused by pre-eclampsia, intrauterine growth restriction, and other pregnancy complications. Neutrophil extracellular traps (NETs) consist of chromatin scaffolds coated with histones, proteases, granules, and cytosolic proteins. Here, we have observed increased levels of NETs in both human OAPS placental tissues and animal models, accompanied by apoptosis increases. In vitro, NETs induce a decrease in trophoblasts proliferation and an increase in apoptosis. In addition, NETs induce oxidative stress and mitochondrial reactive oxygen species (mtROS) production, upregulation of fission-associated mitochondrial proteins coupled with reduced fusion-associated protein levels. It also led to a rise in BNIP3 and autophagy-related protein expressions, along with an increase in autophagosomal numbers. Moreover, mtROS scavenging or knockdown strategies targeting BNIP3 effectively attenuated mitophagic activation alongside trophoblast apoptosis induction. Furthermore, upregulation of BNIP3 expression was evident in placentas from both APS murine models and human OAPS cases. These results suggest that aPL-induced NETs trigger BNIP3-mediated mitophagy, elevate ROS production, induce apoptosis in trophoblasts, and thereby exacerbate placental damage, with implications for our understanding of the pathogenesis of OAPS and devising novel treatment strategies.

Chorioamnionitis (CAM), as a common intrauterine infectious disease, is the leading cause of premature birth, stillbirth, neonatal infection and sepsis. The formyl peptide receptor 2 (FPR2) is a member of GPCRs widely distributed in a variety of tissues and is associated with many inflammatory diseases. With the discovery of FPR2 in human placenta, the possibility of exploring the function of FPR2 in obstetrics is evolving. The Resolvin D1 (RvD1) plays an important role in the resolution of inflammation by combining with FPR2. In this study, we evaluated the role of FPR2 and RvD1 in CAM, not only in the human placenta but also in mouse models. The expression of FPR2 increased in the placenta of CAM patients and the downstream PPARγ/NF‐κB signalling changed accordingly. Moreover, Fpr2^−/− mice were highly susceptible to LPS, displaying a worse CAM symptom, compared with WT mice. By establishing a model of trophoblast inflammation in vitro, it was confirmed that RvD1 rescued the effect of LPS on inflammation by combining with FPR2 and its downstream PPARγ/NF‐κB pathway. Otherwise, RvD1 improved the preterm labour in a mouse model of CAM induced by LPS. Altogether, these findings show that RvD1 alleviated the inflammation of trophoblast in vivo and in vitro through FPR2/PPARγ/NF‐κB pathway, suggesting RvD1/FPR2 might be a novel therapeutic strategy to alleviate CAM.

Purpose: The dysfunction of trophoblast during inflammation plays an important role in PE. Formyl peptide receptor 2 (FPR2) plays crucial roles in the development of inflammation-associated disease. This present study aimed to explore the effect of FPR2 on a trophoblast cellular model of preeclampsia. Methods: The expression of FPR2 in placenta was detected by immunohistochemical staining and western blotting. Transfection of siRNA was used to knockdown FPR2 in HTR-8/SVneo cells. Inflammatory cytokines were detected by ELISA. CCK8, Transwell, wound healing, FACS and tube formation assays were performed to observe the abilities of cell proliferation, migration, invasion, apoptosis and angiogenesis. Western blotting was implemented to clarify that NF-κB signaling pathway was downstream of FPR2. Results: The expression levels of FPR2 were higher in placental tissues of patients with PE. Knockdown of FPR2 expression by siFPR2 or inhibition of its activity by WRW4 decreased the release of proinflammatory cytokines in HTR8/SVneo cells treated with LPS. Knockdown of FPR2 expression or inhibition of its activity further reversed the LPS-induced attenuation of the proliferation, migration, invasion and angiogenesis and increase in apoptosis in HTR8/SVneo cells. Moreover, the NF-κB signaling pathway was activated in both placental tissues of patients with PE and LPS-treated HTR8/SVneo cells. However, the activation was attenuated when FPR2 was knocked down or inhibited. Conclusion: Suppression of FPR2 expression alleviated the effects of inflammation induced by LPS on trophoblasts via the NF-κB signaling pathway, which provided a novel and potential strategy for the treatment of PE.

Purpose: PE is a pregnancy-specific syndrome and one of the main causes of maternal, fetal, and neonatal mortality. PRDX1 is an antioxidant that regulates cell proliferation, differentiation, and apoptosis. The aim of this study is to investigate the effect of PRDX1 on the regulation of trophoblast function by affecting autophagy and oxidative stress in preeclampsia.Methods: Western blotting, RT-qPCR, and immunofluorescence were used to examine the expression of PRDX1 in placentas. PRDX1-siRNA was transfected to knockdown PRDX1 in HTR-8/SVneo cells. The biological function of HTR-8/SVneo cells was detected by wound healing, invasion, tube formation, CCK-8, EdU, flow cytometry, and TUNEL assays. Western blotting was used to detect the protein expression of cleaved-Caspase3, Bax, LC3II, Beclin1, PTEN, and p-AKT. DCFH-DA staining was used to detect ROS levels by flow cytometry.Results: PRDX1 was significantly decreased in placental trophoblasts in PE patients. Following the exposure of HTR-8/SVneo cells to H₂O₂, PRDX1 expression was significantly decreased, LC3II and Beclin1 expression was notably increased, and ROS level was also markedly increased. PRDX1 knockdown impaired migration, invasion, and tube-formation abilities and promoted apoptosis, which was accompanied by an increased expression of cleaved-Caspase3 and Bax. PRDX1 knockdown induced a significant decrease in LC3II and Beclin1 expression, along with an elevated p-AKT expression and a decreased PTEN expression. PRDX1 knockdown increased intracellular ROS levels, and NAC attenuated PRDX1 knockdown-induced apoptosis.Conclusion: PRDX1 regulated trophoblast function through the PTEN/AKT signaling pathway to affect cell autophagy and ROS level, which provided a potential target for the treatment of PE.

As a type of two-dimensional nanomaterial, black phosphorus (BP) has attracted considerable interest for applications in various fields. Despite its advantages, including biodegradability and biocompatibility, recent studies have shown that BP exhibits cytotoxicity in different types of cells. However, no studies have investigated the effects of BP exposure during pregnancy. Herein, we first investigated the effect of gestational exposure to BP nanoparticles (BPNPs) in a mouse model. Our findings indicated that BPNPs exposure restricted fetal growth and hindered placental development. In HTR8/SVneo trophoblast cells, BPNPs inhibited cell proliferation, migration, and invasion and caused apoptosis in a dose-dependent manner. Furthermore, BPNPs induced intracellular reactive oxygen species (ROS) overproduction and extensive mitochondrial damage. We further demonstrated that BPNPs promoted mitophagy via the PINK1/Parkin signaling pathway. Parkin siRNA knockdown rescued BPNPs-induced trophoblast dysfunction, while ROS inhibition attenuated BPNPs-induced cytotoxicity by reducing mitochondrial damage. Finally, treatment with mdivi-1, a mitophagy inhibitor, mitigated mitochondrial membrane potential reduction, excessive mtROS production, and the resulting trophoblast dysfunction. In vivo model investigation indicated that the application of mdivi-1 ameliorated embryonic resorption and fetal growth by alleviating placental damage. In summary, gestational exposure to BPNPs impairs fetal growth by inducing placental trophoblast dysfunction through ROS-regulated, PINK1/Parkin-dependent mitophagy.