Effects Of Smoke Cessation On Expressions Of Nuclear Factor-κB And E-selectin In Smoking Rat Lung Tissue

Objective:To study the relationship between smoking as well as smoke cessation and lung inflammation of chronic obstructive pulmonary disease (COPD) though researching affects of smoking and smoke cessation on expression of nuclear factor-κB (NF-κB) and E-selectin in rat model of smoking.Methods:Thirty-two Wistar rats were randomly divided into the control group, low-does smoking group,high-does smoking group and smoke cessation group,there are eight in every group. Rat smoking device was in accordance with Xu sanlin smoking device. Establish low-does smoking group though breaking in cigarette smoke for 20 weeks, breaking cigarette twice a day and breathing five cigarettes every time,breathing cigarette for six days in a week.Establish high-does smoking group though breaking in cigarette smoke for 20 weeks, breaking cigarette twice a day and breathing ten cigarettes every time,breathing cigarette for six days in a week. Establish smoke cessation group through breathing in cigarette smoke for 20 weeks, breaking cigarette twice a day and breathing ten cigarettes every time,breathing cigarette for six days in a week and breaking away from smoke for 10 weeks. Observe the histopathology change and detect the expressions of NF-kB and E-selectin of rats using immunohistochemistry and hybridization in situ respectively.Results:1 Histopathology change The alveolar structure of the control group is normal and continuous, small bronchial glands have no inflammatory cell infiltration, alveolar wall is integral, and high-does smoking group,low-does smoking group and smoke cessation group exist in varying degrees of alveolar wall thinning or rupture,such as alveolar structure disorder, respiratory bronchiole of the existence of cystic dilatation, alveolar structure integration into the wall and infiltration of a large number of mononuclear cells and lymphocyte, ciliated epithelial broken off, reduction the number of cilia, peaking in the high-does smoking group.2 The expression of NF-κB mRNA and protein level in bronchial endothelial cells The expression of NF-κB mRNA and protein level in bronchial endothelial cells of low-does smoking group (0.41±0.01,0.40±0.01),high-does smoking group (0.43±0.01,0.41±0.04) and smoke cessation group(0.39±0.01,0.37±0.03)was significantly increased compared to that of the control group (0.29±0.03,0.28±0.02) (P<0.05); the expression of NF-κB mRNA and protein level in bronchial endothelial cells of low-does smoking group and smoke cessation group was significantly lower than high-does smoking group (P＜0.05)3 The expression of E-selectin mRNA and protein level in vascular endothelial cells The expression of E-selectin mRNA and protein level in vascular endothelial cells of low-does smoking group (0.38±0.02,0.43±0.05),high-does smoking group (0.42±0.01,0.52±0.03) and smoke cessation group (0.36±0.01,0.47±0.05) was significantly increased compared to that of the control group (0.01±0.04,0.02±0.04) (P<0.05); the expression of E-selectin mRNA and protein level in vascular endothelial cell of low-does smoking group and smoke cessation group was significantly lower than high-does smoking group (P＜0.05)4 The expressions of E-selectin mRNA and protein level have direct correlation with NF-κB mRNA and protein level The expression of E-selectin mRNA and protein level have direct correlation with the expression of NF-κB mRNA and protein level (r=0.80,r =0.89,P<0.01)Conclusion:Smoking can result in the high expressions of NF-κB mRNA and protein level in airway endothelial cells and E-selectin mRNA and protein level in vascular endothelial cell of rat model,both of them have direct correlation. The expression level increases with the augmentation of smoking quantity and decreases after smoke cessation. It means smoke cessation can relieve airway inflammation but cannot eliminate the change. Smoking cessation is effective measure of preventing and controlling COPD.