Polyvinyl chloride nanoplastics suppress homology-directed repair and promote oxidative stress to induce esophageal epithelial cellular senescence and cGAS-STING-mediated inflammation

Nanoplastics (NPs), which are characterized by plastic particles smaller than one micrometer, have emerged as pervasive environmental pollutants, raising concerns about their potential toxicity to living organisms. Numerous investigations have highlighted the tendency of NPs to accumulate in organs, resulting in toxic effects. Despite polyvinyl chloride (PVC) being one of the most prevalent NPs, its impact on the esophagus and the associated underlying mechanisms remain largely unknown. In this study, we investigated the impact of PVC NPs on the esophagus and found that PVC NPs exposure induces oxidative stress and elicits DNA damage responses. Further analysis revealed that PVC NPs inhibit the homology-directed repair (HDR) pathway by suppressing the expression of breast cancer susceptibility gene 2 ( BRCA2 ) and growth factor receptor-bound protein 2 ( GRB2 ), resulting in genomic instability. Additionally, the release of free DNA activates cGAS-STING and the downstream NF-κB signaling, elevating inflammatory factors and chemokines, which further leads to cellular senescence. In vivo experiments corroborated these findings, showing that PVC NPs induced oxidative stress, inflammation, and cellular senescence, subsequently impacting mouse behavior. This study contributes novel insights into the health risks associated with PVC NPs exposure and identifies potential therapeutic targets.