Objective:To explore the role of matrix metalloproteinase 12 (MMP12) in airway macrophages and pulmonary neu-rogenic substance P ( SP ) in the pathogenesis of asthma by analyzing their relationship in different categories of asthmatic patients.Methods:Twenty patients of asthma remission phase ( remission asthma group ) , twenty ones of mild acute exacerbation asthma (mild asthma group) and twenty healthy adults (normal control group) were included,respectively.After lung function was measured,the numbers of macrophage in induced sputum were counted.The expression levels of MMP12 mRNA and protein in sputum macrophages were detected by quantitative reverse transcription polymerase chain reaction and Western blot.The concentration of sputum SP was assayed by enzyme immunometric assay.Results: ( 1 ) Compared with the subjects in normal control group, forced expiratory volume in 1 second%predicted ( FEV1 ) and forced expiratory flow rates at 50% of the forced vital capacity % predicted ( FEF50 ) were much lower and the numbers of sputum macrophages were much higher in the patients in different asthmatic groups.Compared with the patients in remission asthma group,FEV1 and FEF50 were much lower in the ones in mild asthma group.(2) MMP12 expressions in the macrophages and the concentrations of SP in sputum were significantly increased in the patients in different asthmatic groups compared with those in normal control group;Furthermore,MMP12 and SP in mild asthma group were much higher than in remission asthma.(3) In all patients from different asthmatic groups,mRNA expressions of MMP12 in the macrophages were positively correlated with the levels of sputum SP or the numbers of sputum macrophages,whereas negative correlations between mRNA expressions of MMP 12 and FEV 1 or FEF50 were observed.Conclusion: The regulatory imbalance of macrophages′MMP12 and pulmonary neurogic SP may participate in the pathogenesis of asthma and become the potential targets for asthma therapy.

Objective:To establish a new bile duct injury and repair model in mice by generating bile duct distal stricture and proximal dilatation.Methods:The mice were randomly divided into sham operation group, bile duct stricture (BDS) group and bile duct ligation (BDL) group. The dilated bile duct of BDS mice was injured and then repaired 14 days after the modeling operation. Biochemical markers were detected and histopathological changes were analyzed.Results:14 days after the establishment of the model, the body mass in BDL group was significantly lower than that of the sham group ( P<0.05), while the body mass in BDS group was similar to sham group. Compared with the sham group, the bile duct and gallbladder of the BDS group and BDL group were both prominently dilated, but the sum of the diameters of bile duct and gallbladder in BDS group was significantly smaller than that in the BDL group ( P<0.05). Indocyanine green fluorescence imaging confirmed that biliary tract of BDS group could still drain bile. Serum ALT, AST and TBil levels in the BDS group were slightly higher than those in the sham group (all P<0.05), but significantly lower than those in the BDL group ( P<0.05). Bile ducts of BDS mice were injured by notching and repaired with bile duct path. 30 days after the repairing, HE staining showed that the bile duct epithelium around the patch was arranged in orderliness. Immunohistochemistry confirmed the positive staining of green fluorescent protein (EGFP) and CK19 in those groups. Conclusion:This model of bile duct injury and repair in mice can provide a new model for the study of the mechanism of bile duct injury and repair and the evaluation of tissue engineering bile duct.