BDE-47 Alters Surface Glycans and microRNA Cargo of Macrophage-Derived Vesicle Subpopulations Modulating EV-Mediated Senescence Signaling

Background Extracellular vesicles (EVs) are key mediators of intercellular communication, and their molecular cargo and surface properties can be profoundly influenced by external stimuli. In the context of inflammation, immune cells increase EV release to regulate immunity and metabolism. We previously demonstrated that the widespread environmental pollutant BDE-47 modulates macrophage innate immune responses through inflammasome inhibition and EVs biogenesis. In the present study, we investigated how BDE-47 exposure influences the heterogeneity of EVs released by THP-1 M(LPS) macrophages by characterizing their physical properties and surface markers. We also assessed the impact of BDE-47 on the microRNA cargo of different EV subtypes and investigated EVs functional role in modulating senescence-associated processes in heterologous LNCaP target cells Methods EV populations were isolated from BDE-47-treated THP-1 M(LPS) macrophages by differential centrifugation, allowing the separation of small (sEVs) and large EVs (lEVs). Their size, concentration, and surface characteristics were assessed through NTA, DLS, Western blotting, and lectin-binding assays, while EV-associated miRNAs were profiled by microarray. Pathway enrichment analysis was conducted to identify key biological pathways altered due to EVs treatment. The downstream effects of different subtypes of EVs (sEVs ^BDE−47 and lEVs ^BDE−47 ) were evaluated on LNCaP cells by BrdU incorporation and β-galactosidase senescence assays. In addition, transcriptional and Western Blot analyses were performed to investigate the expression of genes involved in cell cycle regulation. Results Our results show that BDE-47 does not alter EV size but profoundly reshapes their molecular identity. Specifically, we observed changes in glycan surface expression and a selective modulation of miRNA sorting in both sEVs and lEVs. Bioinformatic analysis revealed a distinct BDE-47–associated EV-miRNA signature linked to the regulation of cell cycle checkpoint pathways. Functional assays further demonstrated that sEVs ^BDE−47 and lEVs ^BDE−47 differentially influence proliferation, induction of senescence, and the expression of p16 and p21 genes in LNCaP cells. Conclusions Our findings highlight EVs as central targets and mediators of pollutant-induced cellular effects, unveiling a novel mechanism by which environmental contaminants interfere with EV-mediated communication and influence the behaviour and functions of recipient cells.