Concurrent ozone and high temperature exacerbates nasal epithelial barrier damage in allergic rhinitis mice: Insights from the nasal transcriptome and nasal microbiota.

The global ambient temperature has been rising in recent decades and high temperature is usually accompanied by ozone (O) pollution. Environmental change is an underlying factor for the increased prevalence of respiratory allergic disease. However, the potential mechanisms are complex and remain elusive. This study was performed to reveal toxic effects and molecular mechanisms of O or/and high temperature induced allergic rhinitis (AR) deterioration. The results indicated that O and high temperature co-exposure exacerbated rhinitis symptoms, destroyed ultrastructure of nasal mucosa and down-regulated the expression of nasal epithelial barrier structural proteins ZO-1 and occludin. Moreover, the levels of total protein and lactate dehydrogenase (LDH) in nasal lavage fluid and the levels of IL-1β and TNF-α in serum also exhibited a significant upward trend. Transcriptomic analysis revealed that immune and inflammatory signaling pathways such as IL-17 signaling pathway was involved in the combined toxicity of O and high temperature. Microbiome examination showed that Prevotella and Elizabethkingia were linked to nasal injury. What's more, spearman correlation analysis revealed correlations among nasal microbiota dysbiosis, inflammation and injury. To sum up, the present study assessed the combined toxicity of O and high temperature and found potential mechanisms, which provided important experimental evidence for making preventive intervention strategies and protecting vulnerable populations.