Expression Of RELMβ In COPD Rats Lung Tissue And Correlation With IL-8, IL-10and TNF-α

Objective To explore the expression of RELMβ in the rats lung of smoking induced chronicobstructive pulmonary disease (COPD) model,and analyze its correlation with IL-8、IL-10andTNF-α in Bronchoalveolar lavage fluid (BALF) and serum,further to study the potential role ofRELMβinthe airway remodeling and pathogenesis of COPD。Methods70specific pathogen-free male Wistar rats, with medium weight of180g of6week-old,were randomly divided to normal control groups and COPD model groups by randomnumber table.They were7subgroups with5rats in every group,including to defferent weeks.12cigarettes were burned twice a day to contaminate the rats, lasted for2weeks,4weeks,8weeks,12weeks,16weeks,20weeks and24weeks respectively to construct COPD model; the normalcontrol group was unexposed to pollutants，housed under the equivalent condition.Took recordsof weight,the rats were euthanized by exsanguination,blood, and lung tissues were removed,BALF was gathered from left lung. Hmatoxylin and eosin stained the specimen for pathologystudy. Enzyme linked immunosorbent assay technical detecteing the expression of IL-8, IL-10and TNF-α in BALF and serum.Western bloting technic detecting the expression of RELMβ inthe lung tissue.Data was stored and analyzed via software SPSS13.0for windows.Results(1)Compared with the normal group,the COPD group rats gained weight slowly， withsignifinatly decreased weightbetween4-24w group(P<0.01).(2) Scarcely pathological change in lung tissue from control group was observed,reversely,thepathological change in COPD group occured on4w group, significantly from16w group to24wgroup. Compared with normal control groups, bronchiolo-alveolar attachmentdestruction,airway wall thickening, epithelial detachment, inflammatory cell infiltration, luminanarrowing, increased airway smooth muscle mass, fusion of pulmonary alveole andneovascularisation in rat lung tissue in COPD groups were observed.(3) Western blot analysis and immunohistochemical sections showed the expression of RELMβincreaseing gradually in COPD group，obviously experssed in20and24weeks group.(4) The expression of IL-8in serum of model rats increased from4-24w group, there was statistical significant (P＜0.05);IL-8from BALF elevated in COPD groups compared withnomoral groups (P<0.05) except the2w and4w group. IL-10in serum of model rats decreaseddamaticly between12-24w, the difference was statistical significant (P＜0.05)；IL-10in BALFof model rats decreased between12-24w, the difference was statistically significant except the2w，4w and8w group(P＜0.05). Compared with normal group, TNF-α in serum of COPD ratswas elevated between8-24weeks (P<0.05); TNF-α in BALF of COPD rats started increasefrom4w group(P<0.01） and was obviously elevted from8w to24w group (P<0.01).(5) Expression of RELMβ had positive correlation with IL-8and TNF-α both in serum (r＝0.926，0.819，both P<0.05)and BALF (r＝0.817，0.931，both P<0.05),while negative correlationwith IL-10both in serum and BALF(r＝-0.891，-0.864，both P<0.05).Conclusions RELMβ was overexpression in COPD rats lung tissue compared with normalcontrol group,in posistive correlation with the level of IL-8and TNF-α both in serum andBALF,while negative correlation with IL-10both in serum and BALF.，indicated that RELMβas a mediator of inflammation playing an important role in airway inflammation and airwayremodeling.