Mechanism Of Cold Stimuli Aggravating Allergic Rhinitis In An Ovalbumin-induced Mouse Model Via TRPM8 Channels

Objective:To investigate the effects of cold air on upper airway inflammation and hyperresponsiveness in allergic rhinitis mice and its underlying mechanism.Methods:The mice were randomly divided into control group,allergic rhinitis group,OVA+cold stimuli group and OVA+ cold +TRPM8 antagonist(RQ-00203078)intervention group,with 6 mice in each group.Allergic rhinitis model was challenged with ovalbumin(OVA).The control group was replaced by normal saline,the OVA+ cold group was given cold stimuli for 4h daily on the basis of OVA sensitization,and the OVA+ cold stimuli + RQ-00203078 intervention group was given OVA+ cold stimuli and RQ-00203078 intragastric administration for 7 days.Twenty-four hours after the last challenge the mice were sacrificed.The nasal mucosa of mice was taken for routine HE staining to observe the local pathological changes of nasal mucosa.The expression of TRPM8 in nasal mucosa of mice were observed by immunohistochemistry.The levels of OVA-specific immunoglobulin E(OVA-s Ig E)in serum were detected by ELISA.The levels of inflammatory factors IL-4,IL-5,IL-33 and TSLP in nasal mucosa were detected by PCR.Results:AR group,OVA+ cold stimuli group,OVA+ cold stimuli+ RQ-00203078 intervention group mice models were finished successfully.HE staining showed that the infiltration of eosinophils in AR group and cold stimuli group was reduced in RQ-00203078 group compared with AR group.Immunohistochemical staining showed that TRPM8 was strongly expressed in nasal epithelium in OVA + cold stimuli group,and moderately expressed in RQ-00203078 intervention group.ELISA results showed that the levels of serum OVA-s Ig E in AR group,OVA+cold stimuli group and RQ-00203078 intervention group were higher than those in control group,but there was no significant difference among the three groups.The results of PCR showed that the levels of Th2 cytokines and proinflammatory cytokines in AR group and OVA+ cold stimuli group were significantly higher than those in control group,and the levels of Th2 cytokines and proinflammatory cytokines in RQ-00203078 intervention group were lower than those in OVA+ cold stimuli group.Conclusion:In this study,the AR mouse model was established by OVA sensitization and challenge.After cold stimuli,the local and systemic inflammatory response of nasal mucosa in AR mice was aggravated.After the intervention of RQ-00203078,the inflammatory response was alleviated,and the difference was statistically significant.The results showed that cold stimulation could aggravate the inflammation of nasal mucosa in AR mouse model.Treatment of AR mouse model with RQ-00203078 showed that the substance could alleviate local inflammation of nasal mucosa to some extent.These results suggest that cold stimuli may play a pro-inflammatory role through TRPM8,and this effect can be blocked by antagonists,and the specific mechanism needs further study.