Abstract: Objective To explore the different expression of transient receptor potential protein -8 (TRPM8) and related signal transduction mechanism in airway epithelial tissue between the patients with COPD and healthy subjects. Methods The distribution and different levels of TRPM8 protein in human bronchial epithelial was viewed by immunohistochemistry. TRPM8 protein and mRNA were further detected by PCR and Western blot, respectively. The 16HBE human airway epithelial cells were stimulated with cold temperature (18℃). Cells were divided into 5 groups：a control group (incubated at 37℃)，a cold stimulation group, a cold stimulation +BCTC group, a cold stimulation+TRPM8 shRNA group, a cold stimulation+control shRNA group. The relative concentration of intracellular Ca2+ were measured by laser confocal. Results TRPM8 protein was mainly distributed in the membranes of basal cells or small particle cells within the bronchial epithelium. The ratio of integrated optical to area and the levels of TRPM8 mRNA and protein within the bronchial epithelium were significant higher in COPD group when compared with control group（P<0.05）.The relative concentration of intracellular calcium in cold stimulation group was higher than that of control group(P<0.05). BCTC and TRPM8 shRNAreduced intracellular calcium, compared with single cold stimulation group (P<0.05). Conclusion It is possible that up-expression of TRPM8 in subjects with COPD will be coupled with a greater sensitivity to cold than normal subjects.

Key words: Chronic obstructive pulmonary disease, Cold air, Transient receptor potential melastatin cation channels