Abstract
BACKGROUND: Ozone (O(3)) pollution disrupts pulmonary circadian rhythms, yet the molecular mechanisms remain elusive. The Notch signaling pathway, critical for lung homeostasis, may crosstalk with the circadian clock system. OBJECTIVE: This study elucidates the role of the Notch signaling pathway in O(3)-induced lung circadian rhythm disruption. METHODS: C57BL/6J mice were acutely exposed to O(3) (1.0 ppm, 3 h). Lung tissues were collected 24 h post exposure. Transcriptome sequencing coupled with GSEA identified dysregulated pathways; IHC and RT-qPCR validated core genes; GEO dataset (GSE58244) reanalysis assessed Notch3/4 knockout effects. RESULTS: O(3) activated Notch signaling (NES = 1.85, FDR = 0.034) and disrupted the circadian pathway (NES = 1.84, FDR = 0.029), downregulating Bmal1 while upregulating Per2/3 and Notch3/4 (p < 0.05). Strong correlations (r > 0.8) existed between core genes of both pathways. Notch3/4 knockout exacerbated circadian disruption in a time-dependent manner upon O(3) exposure. CONCLUSION: O(3) induces lung circadian disruption via Notch3/4 activation, which provides novel mechanistic insights into pollutant-induced lung injury.