Integrated network toxicology and transcriptomics reveal NF-κB signaling as a key mediator of TDCPP-induced inflammatory responses in human microglia

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is a ubiquitous organophosphorus flame retardant linked to neurodevelopmental disorders. However, the molecular cascades driving its neurotoxicity, particularly microglial-mediated neuroinflammation, remain incompletely understood. Here, we applied an integrated systems toxicology strategy combining network toxicology, transcriptomics, and experimental validation to identify key pathways mediating TDCPP-induced neurotoxicity. Initial in silico screening of 14 organophosphorus flame retardants (OPFRs) identified TDCPP as a high-priority candidate with prominent predicted neurotoxicity. Integration of network-predicted pathways with transcriptomic profiles from TDCPP-exposed human microglia (HMC3) identified the NF-κB signaling pathway as a key mediator. Experimental validation confirmed that TDCPP activated the canonical NF-κB pathway, characterized by p65 phosphorylation, IκBα degradation, p65 nuclear translocation, and NFKB1 upregulation. This triggered the transcription of pro-inflammatory mediators (IL6, IL1B, TNF, PTGS2) and a secretome shift involving cytokine surges and compensatory IL-10 release. Pharmacological blockade using BAY 11-7082 and siRNA-mediated knockdown of p65 effectively reversed these pro-inflammatory alterations, establishing a causal link. Collectively, this study demonstrates that TDCPP disrupts microglial homeostasis by hijacking the NF-κB signaling axis. These findings indicate that TDCPP alters microglial immune homeostasis and triggers inflammatory responses, which may serve as a mechanistic link to OPFR-associated neurotoxicity, providing a potential target for mitigation.