The Effect And Expression Of Calcium-binding Protein S100A8 And S100A9 On Rats Alveolar Macrophage With Chronic Obstructive Pulmonary Disease

Objective:In order to explore the role and the expression of calcium-binding protein S100A8 and S100A9 in the alveolar macrophage of Chronic Obstructive Pulmonary Disease(COPD)rats.Methods: 12 wistar rats were randomly divided into normal control group and COPD group.COPD model was established by exposing the rats to cigarette smoke and injected lipopolysaccharide(LPS)in bronchus for one month.The pathological changes of the lung tissue of both groups rats were observed under light microscope,and then the pulmonary mean linear intercept(MLI),mean alveolar number(MAN)and proportion(PAA)were analyzed by image analysis system.Total cells counts and the proportions of alveolar macrophages,lymphocytes,neutrophils,in BALF of two groups rats were examined by Wright's staining methods.Rat alveolar macrophages from the control group and COPD group were isolated in vivo and cultured,and then challenged with different concentrations of S100A8 and S100A9 protein for 6 hours and 24 hours.The levels of IL-6,IL-8 and TNF-? in the supernatants were measured by ELISA.The methods in situ hybridization technique and immunohistochemical method were used to observed The expression of S100A8/A9 protein,S100A8 and S100A9 mRNA of alveolar macrophages cultured in vitro.Results:(1)Compared with the control group,the lung tissue of theCOPD rats appeared the typical pathological changes of COPD,and the MLI and PAA in COPD group were higher than the normal,while MAN was just on the contrary(P<0.05).(2)Total cell counts and all the inflammatory cells in BALF of COPD rats were significantly higher than those of the normal(P<0.05).The absolute value of the alveolar macrophages were increased the most obvious.(3)Observed by in situ hybridization technique,the S100A8 and S100A9 mRNA mainly expressed in the cytoplasm and membrane of the rat alveolar macrophage.Stastistical analysis shows that the expression of S100A8 and S100A9 mRNA in alveolar macrophages of COPD rats were up-regulated signifcantly(P<0.05).(4)Observed by immunohistochemistry,the S100A8/A9 protein mainly expressed in cytoplasm and membrane of the rat alveolar macrophage too.Stastistical analysis shows that,compared with the control group,the levels of S100A8/A9 protein in alveolar macrophages from COPD rats were also up-regulated significantly(P<0.05).(5)S100A8 and S100A9 stimulated IL-6,IL-8 and TNF-? release from alveolar macrophages of the normal and COPD rats time-dependently and dose-dependently.The levels of IL-6,IL-8 and TNF-?were higher in alveolar macrophages of the COPD group than those of the control group at the same time and dose of S100A8 and S100A9.Compared with the same dose of S100A8 and S100A9 stimulus rat alveolar macrophage.When S100A8 deal with two groups of rats alveolar macrophages,the concentration of IL-8 and TNF-a in the supernatant were higher than S100A9,when it deals with two groups of rats alveolar macrophages in the same condition.(P < 0.05);While higher dose S100A8 stimulates the COPD and normal rat alveolar macrophage,the leveal of IL-6also was higher than S100A9 when it stimulates two groups of rats alveolarmacrophages to secrete the quantity of IL-6(P < 0.05).Conclusion:(1)Cigarette smoke daily and injecting LPS in bronchus can establish a rat COPD model.(2)The expression of S100A8/A9 protein,S100A8 and S100A9 mRNA in rat alveolar macrophages of COPD were higher than the normal control group.(3)S100A8 and S100A9 increased IL-6,IL-8 and TNF-a levels in the supernatant of alveolar macrophages of rats in concentration-dependent and time-dependent.(4)S100A8 and S100A9 stimulate alveolar macrophages of COPD rats to produce IL-6,IL-8 and TNF-a increase more significantly than normal rats alveolar macrophages.(5)S100A8 stimulate rat alveolar macrophages to secrete IL-6,IL-8 and TNF-a increased obviously stronger than S100A9.