AIM:To investigate the potential mechanism of neutrophil extracellular traps(NETs)in the pla-centa during the pathogenesis of preeclampsia(PE).METHODS:Differential neutrophil infiltration in PE versus normo-tensive placentas was assessed using placental transcriptome sequencing data.Single-cell sequencing analysis of GSE173193 dataset was conducted to evaluate the expression of NETs formation-related genes in neutrophils from PE pla-centa and control placenta.Immunofluorescence and ELISA were used to measure NETs levels in placental tissues.Fol-lowing NETs generation and treatment of human extravillous trophoblast(EVT)HTR8/Svneo strain with NETs,RNA se-quencing was utilized to identify potential signaling pathways through which NETs regulate trophoblast function.RE-SULTS:Neutrophil infiltration,and expression of NETs formation critical genes,MPO(myeloperoxidase)and ELANE(elastase,neutrophil expressed),in neutrophils were significantly increased in PE placentas compared with controls.The level of NETs was elevated in PE placentas as well.The NETs significantly inhibited the migration of HTR8/Svneo cells.Disrupted F-actin arrangement,aggregate formation,and reduced paxillin expression were observed in NETs-treated HTR8/Svneo cells.Single-cell sequencing analysis revealed that focal adhesion and stress fiber pathways were down-regu-lated in the EVT of PE placenta.CONCLUSION:Neutrophil infiltration and NETs formation were increased in PE.The NETs may inhibit EVT migration by inducing stress fiber disassembly and down-regulating paxillin expression,thereby dis-rupting cytoskeletal organization and focal adhesion formation.

AIM:To investigate the potential mechanism of neutrophil extracellular traps(NETs)in the pla-centa during the pathogenesis of preeclampsia(PE).METHODS:Differential neutrophil infiltration in PE versus normo-tensive placentas was assessed using placental transcriptome sequencing data.Single-cell sequencing analysis of GSE173193 dataset was conducted to evaluate the expression of NETs formation-related genes in neutrophils from PE pla-centa and control placenta.Immunofluorescence and ELISA were used to measure NETs levels in placental tissues.Fol-lowing NETs generation and treatment of human extravillous trophoblast(EVT)HTR8/Svneo strain with NETs,RNA se-quencing was utilized to identify potential signaling pathways through which NETs regulate trophoblast function.RE-SULTS:Neutrophil infiltration,and expression of NETs formation critical genes,MPO(myeloperoxidase)and ELANE(elastase,neutrophil expressed),in neutrophils were significantly increased in PE placentas compared with controls.The level of NETs was elevated in PE placentas as well.The NETs significantly inhibited the migration of HTR8/Svneo cells.Disrupted F-actin arrangement,aggregate formation,and reduced paxillin expression were observed in NETs-treated HTR8/Svneo cells.Single-cell sequencing analysis revealed that focal adhesion and stress fiber pathways were down-regu-lated in the EVT of PE placenta.CONCLUSION:Neutrophil infiltration and NETs formation were increased in PE.The NETs may inhibit EVT migration by inducing stress fiber disassembly and down-regulating paxillin expression,thereby dis-rupting cytoskeletal organization and focal adhesion formation.

Inflammatory caspase-11 senses and is activated by intracellular lipopolysaccharide (LPS) leading to pyroptosis that has critical role in defensing against bacterial infection, whereas its excess activation under pathogenic circumstances may cause various inflammatory diseases. However, there are few known drugs that can control caspase-11 activation. We report here that scutellarin, a flavonoid from Erigeron breviscapus, acted as an inhibitor for caspase-11 activation in macrophages. Scutellarin dose-dependently inhibited intracellular LPS-induced release of caspase-11p26 (indicative of caspase-11 activation) and generation of N-terminal fragment of gasdermin D (GSDMD-NT), leading to reduced pyroptosis. It also suppressed the activation of non-canonical nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome as evidenced by reduced apoptosis-associated speck-like protein containing a CARD (ASC) speck formation and decreased interleukin-1 beta (IL-1β) and caspase-1p10 secretion, whereas the NLRP3-specific inhibitor MCC950 only inhibited IL-1β and caspase-1p10 release and ASC speck formation but not pyroptosis. Scutellarin also suppressed LPS-induced caspase-11 activation and pyroptosis in RAW 264.7 cells lacking ASC expression. Moreover, scutellarin treatment increased Ser/Thr phosphorylation of caspase-11 at protein kinase A (PKA)-specific sites, and its inhibitory action on caspase-11 activation was largely abrogated by PKA inhibitor H89 or by adenylyl cyclase inhibitor MDL12330A. Collectively, our data indicate that scutellarin inhibited caspase-11 activation and pyroptosis in macrophages at least partly via regulating the PKA signaling pathway.