Correlation Analysis Between Clinical Features And Expression Of Transient Receptor Potential Melastatin 8 In Nasal Epithelial Cells Of Cold Air Sensitive-Asthmatic Patients

OBJECTIVE: To explore the clinical characteristics,expression of transient receptor potential melastatin 8(TRPM8)receptors and inflammatory factors in nasal epithelial cells of asthmatic patients who are sensitive to cold air stimulus.METHODS: Patients were divided into asthma group(7 cases)and normal control group(8 cases).The expression and localization of TRPM8 in the nasal epithelium were examined by immunohistochemistry in two groups.The asthma patients were divided into 2 groups by whether they are sensitive to cold air stimulus(50 cases and 45 cases respectively).All cases finished pulmonary function,fractional exhaled nitric oxide(FeNO)test,Asthma Control Test(ACT),Immunoglobulin E(IgE)and complete blood count.The mRNA expression of TRPM8 and inflammatory cytokines of sensitive to cold group(11 cases)and insensitive to cold group(11 cases)were examined by quantitative reverse transcription polymerase chain reaction(qRT-PCR).Correlation analysis was performed to explore the relationship between TRPM8,inflammatory cytokines and clinical related parameters.RESULTS: The nasal epithelial cells expressed TRPM8,and the expression of TRPM8 in nasal epithelium in asthma group was significantly higher than control group.The scores of ACT,forced expiratory volume in the first second of expiration(FEV1)/forced vital capacity(FVC),percentage of predicted FEV1(FEV1%pred)and FeNO in cold air sensitive group were lower than cold air non-sensitive group(p<0.05).The percentage of blood neutrophils,IgE value and the number of acute exacerbations in the past year in cold air sensitive group were significantly higher than cold air non-sensitive group(p<0.05).No significant difference was detected in the percentage of eosinophils in serum between the two groups(p>0.05).The mRNA levels of TRPM8,interleukin(IL)-6,IL-1β,matrix metalloprotein(MMP)-9 and tumor necrosis factor(TNF)-a increased significantly in cold air sensitive group(p < 0.05).The relative expression level of TRPM8 mRNA is positively related to IL-6,IL-1β,TNF-α and the number of acute exacerbations in the past year,and is negatively related to FEV1/FVC,FEV1%pred and the score of ACT.Conclusion: Asthma patients who are sensitive to cold air stimulus present more susceptible to cold air and perform poorer lung function and more serious inflammatory response than those who are not sensitive to cold air because of the higher expression of TRPM8.Neutrophil phenotype is the most inflammatory phenotype in airway,which is different from the classical asthma.