Roles Of Matrix Metalloproteinase In The Extracellular Matrix Remodeling Of Airways In Rat COPD Models

Objective: (1) to establish chronic obstructive pulmonary disease (COPD) rat modelsby smoking and smoking as well as intratracheal instillation lipolysaccharide (LPS) respectively, and observe its histopathological changes, lung function, blood gas exchange and morphologic characteristic of the airway extracellular matrix remodeling. (2) The hydroxyproline level in the bronchial lung tissue was measured and its correlation with lung function (FEy0 3/FVC, airway resistance) was carried out in order to evaluate the role of extracellular matrix remodeling in the airflow obstruction. (3) The role of matrix metalloproteinase (MMPs) and its tissue inhibitor of metalloproteinase (TIMPs) in the airway extracellular matrix remodeling of CQPD were mainly investigated. (4) to observe the role of N-acetylcysteine (NAC) which can scavenge oxygen free radicals, inhibitor of protein kinase C (LI7) and TGF- ~ monoclonal antibody(TB21) in regulation of MIVIPs/TIMPs and their influence to the extracellular matrix remodeling of the airway wall. Method: 1. 78 male wistar rat were randomly divided into 6 groups: (1) the healthy control groups: breed 4 weeks and 12 weeks respectively, each of the group 12 rats, (2) model group 1:12 rats, the rats were received instillation of 200 i-~ g LPS at the lth and 14th day of the experiment respectively. Rats were exposed to the 5% smoke concentration in the chamber (72L) for 0.5h every morning lasted 4 weeks. (3) model 5 grouP II: l2 rats, Ras were only eXPosed to the smoke as meniioned above and lastCd3 months. The COPD rat models were established as saxne as model grOuP I in thefOllowhg 3 grouPs: (4) NAC grouP: l2 rats, the rats were instil1ed into the stomachNAC 50mg/kg before they eXPosed to the cigarette smoke excePt the lth and l4th day(5)H7 grouP: l0 rats, the rats received 0.2mg of H7 through the tail veins at lth andl4th day after intracheal instillation of LPS, (6)TGF- D monoclonal anibody grouP. 7rats, flVe days ds each intracheal instillation of LPS, the rats received 0.5mg of TB2lthrough the tail veins reSPectively 2.The models of lung fUnction were measured bymeans of "calculator for small animal lung function". 3. The blood gas exchange wasalso measured. 3.The area of ePithelial layer, smooth muscle layer nd lamina Propriain bronchi were measured by means of image analyzer 4.The hydroxyProline level inbrOnchial lUng tissue was measured and anaysis its relationshiP wtth lUng function.5.The flbroblasts and lyInPhocytes of lamina propria in bronchi and macroPhages inalveolar were couthed in oil microscope. 6.The mRNA eXPression of MMP-9, wn-2and TIMP-l were determined by RT-PCR. 7.The enZyme activities of wns wereexamined by gelatin SDS-PAGE. 8.The protein eXPression and localization of MMP-2,Mmp-9, TIMP-l, TGF- P I recePtor and TGF- D II recePtor were observed bydriuno-histoMical technology 9. Collagen staining were carried oni by sPecialstAning.ResuIt: 1. The rat model grouP I and II have the corn-mon pathological changes ofchronic bronchitis and obsmictive eInPhysema. It shows that the proliferation ofepitheial ce1l, smooth musc1e cell and fibroblaSt, ePithelial layer rising into the driens,goblet cell and mucus gland significanly increased, muus accUmulation in lumens,and lMhocytes infiltrating the airway wa1l, macroPhages in alveolar weresignificantiy increased. Quantiies of alveolar macrophages phagocyting smokegranules were observed near bronchi and arteroles especiaIly model grouP II. 2.FEV0,NVC wer much lower and its Rs, R were signficanly increased in the modelgrouP I and MVV FEV,,NVC were significantiy decreased in model grOuP IIcomPared those dri their control grouP...