PMID: Ecotoxicol Environ Saf. 2021 Nov 16 ;228:112998. Epub 2021 Nov 16. PMID: 34798361 Abstract Title: Fine particulate matter exposure exacerbated nasal mucosal damage in allergic rhinitis mice via NLRP3 mediated pyroptosis. Abstract: BACKGROUND: The incidence of nasal allergy/allergic rhinitis (AR) is rising worldwide, which has become a serious public health problem. Epidemiological studies point that exposure to environmental PMis closely linked to AR aggravation, however, the exactly mechanism is not clear. This study was performed to reveal molecular mechanisms of PM-induced AR deterioration.METHODS: Morphology and element analysis of PMwas examined by scanning electron microscopy (SEM) and Energy Dispersive Spectrometer (EDS). A total of 24 female C57BL/6 mice were divided into three groups (control group, AR group, and PM+ AR group, each group contains 8 mice). Mice from AR group and PM+ AR group were intraperitoneally injected with OVA suspension (0.004% OVA+3% aluminum hydroxide) on days 1, 7, and 14. 0.2 mL /kg B.W. for sensitization; then the same mice were intranasal instilled with 5% OVA solution daily for 7 days to established AR mice model (each nostril for 10 μl, day 15-21). The mice were intranasal instilled PBS (control group and AR group, each nostril for 10 μl) or PM(AR + PMgroup, 4.0 mg/kg b.w., each nostril for 10 μl) at the same way from day 23-29. The nasal symptoms were evaluated after the last instillation of PM. Pathological changes and ultrastructure of nasal mucosa were observed by HE staining and SEM. Goblet cells hyperplasia was performed by Periodic acid-Schiff (PAS) staining. NLRP3, Caspase-1, GSDMD and IL-1β protein expression were assessed by immunohistochemical (IHC) staining.RESULTS: Exposure to PMaggravated rhinitis symptom, promoted the secretion of serum IgE level and destroyed ultrastructural of nasal mucosa. Interestingly, NLRP3, Caspase-1 GSDMD and IL-1β protein expression were obviously elevated. NLRP3 /Capase-1/ GSDMD meditated cell pyroptosis participated in the process of AR exacerbation. However, macrophage is not the main effector cell.CONCLUSION: PMexposure induces aggravation of allergic rhinitis, which is related to NLRP3 inflammasome meditated caspase-1 activation and cell pyroptosis in nasal mucosal.
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