The Effects Of Methylprednislone On Alveola Septal Apoptosis In Autoimmune Emphysema Of Rats

Objective:To investigate the effects of methyprednislone on the expression of tumoralveolar septal cell apoptosis of autoimmune emphysema rats,Our study is aimed atproviding a theoretical basis of Chronic obstructive pulmonary disease (COPD)pathogenesis and it’s treatment.Methods:Twenty four rats were randomly divided into three groups: normal controlgroup (n=8), model group and intervention group (methylprednisolone sodium succinate).Intraperitoneal injection of primary cultured human umbilical vein endothelial cells wasgiven to establish the autoimmune emphysema models, intervention group was injectedwith methylprednisolone in intraperitoneally for intervention at the meantime, and normalcontrol group was received intraperitoneal injection of adjuvant only. The levels of TNF-αMMP-9,IL-8and VEGF in BALF were measured with ELISA. Pathological changes wereobserved in lung tissues stained by hematoxylin eosin, Mean liner intercept (MLI) andmean alveolar numbers (MAN) were measured. The localization of VEGF and VEGFR-2in lung tissues was detected by immunohistochemical analysis. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) technique was carried out to detectthe alveolar septal cells apoptosis.Results:(1) The MLI was higher in the model group than the normal control group, whilethe MAN was lower in the model group; MLI of the intervention group was lower than themodel group, but the MAN was higher, the difference being significant(P<0.05).(2) Thelevels of TNF-α,MMP-9in BALF of the model group were higher than the normal controlgroup, but the concentration of VEGF in the model group was lower than in the normalcontrol group; The concentrations of TNF-α, MMP-9in BALF of the intervention groupwere lower than the model group, but the VEGF concentration was higher, the differencebeing significant(P <0.05). No differences were found in IL-8concentration between themodel group and the control group (P>0.05).(3) The localization of VEGF and VEGFR-2in lung tissues of the model group was lower than the normal control group; The expression of VEGF,VEGFR-2in lung tissues of the intervention group was higher than inthe model group, the difference being significant (P<0.05).(4) The index (AI) for alveolarseptal cell apoptosis was higher in the model group than the normal control group, but theindex (AI) for alveolar septal cell apoptosis in the intervention group was higher in themodel group, the difference being significant (P<0.05).Conclusion:(1) Higher TNF-α, MMP-9, lower VEGF in BALF and lowerVEGF,VEGFR-2in lung tissues instead of IL-8may cause apoptosis of alveolar septalcells and contribute to the pathogenesis of autoimmune emphysema of rats.(2)Methyprednislone prevents the development of autoimmune emphysema of rats, becauseit may reduce the levels of TNF-a,MMP-9and the index (AI) for alveolar septal cellapoptosis instead of the level of VEGF and VEGFR-2.