Quit Smoking Effects Of Smoking Rat Airway Epithelial Nuclear Factor-kappa B, Matrix Metalloproteinase-9 And Matrix Metalloproteinase Tissue Inhibitor Of Metalloproteinase-1 Expression

Objective To investigate the effects of smoking and smoking cessation on airway inflammation and remodeling in chronic obstructive pulmonary diseases through detecting mRNA and protein expressions of nuclear factor-κB(NF-κB), cell matrix metalloproteinase-9 (MMP-9) and cellulartissue inhibitor of metalloproteinase-1(TIMP-1) in airway epithelial cells of smoking and smoking cessation rats.Method Twenty-four male Wistar rats were randomly divided into control group,smoking group and smoking cessation group,eight in each group.Hybridization in situ and immunohistochemistry were used to detect mRNA and protein expressions of NF-κB,MMP-9 and TIMP-1 in airway epithelial cells of rats.Results (1) Compared with control group (0.29±0.06; 0.29±0.06), mRNA and protein expressions of NF-κB in smoking group (0.45±0.04; 0.41±0.03) and smoking cessation (0.40±0.05; 0.37±0.03) were higher (all P< 0.05). The mRNA expressions and protein expressions of NF-κB in smoking cessation group were lower than those in smoking group (all P< 0.05). (2) Compared with control group (0.30±0.06; 0.30±0.06), mRNA and protein expressions of MMP-9 in smoking group (0.52±0.03; 0.51±0.07) and smoking cessation group (0.38±0.03; 0.33±0.02)were higher (all P< 0.05). The mRNA expressions and protein expressions of MMP-9 in smoking cessation group were lower than those in smoking group (all P< 0.05). (3)Compared with control group (0.26±0.04; 0.26±0.04), mRNA and protein expressions of TIMP-1 in smoking group (0.49±0.05; 0.37±0.03) and smoking cessation group (0.42±0.04; 0.35±0.03) were higher (all P< 0.05).The mRNA expressions and protein expressions of TIMP-1 in smoking cessation group were lower than those in smoking group (all P< 0.05). (4)Compared with control group (1±0.02; 1±0.02),MMP-9/ TIMP-1 mRNA and protein expressions were larger than one in smoking group (1.07±0.14; 1.37±0.19) and less than one in smoking cessation group (0.92±0.13 0.94±0.10) (all P< 0.05). (5) The mRNA and protein expressions of NF-κB and MMP-9 were positively correlation (r=0.87,0.66, all P< 0.05).Conclusion In airway epithelial cells of smoking rats, mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 increase and MMP-9/TIMP-1 is larger than one.After stopping smoking, mRNA and protein expressions of NF-κB, MMP-9 and TIMP-1 decrease, and MMP-9/TIMP-1 is less than one. This experiment explains that smoking can cause the airway inflammation and remodeling, smoking cessation can reduce airway inflammation and remodeling.