Effects of CpG-oligodeoxynucleotides and dexamethasone on airway remodeling and expression of MMP-9 and TIMP-1 in murine model of chronic asthma

AIM: To observe the changes of airway inflammation and remodeling in a murine model of chronic asthma with CpG-oligodeoxynucleotides(CpG ODN) and dexamethasone(DXM) treatments.METHODS: BALB/c mice were sensitized and repeatedly challenged with ovalbumin.Pathological slides were prepared from left lung and stained with hematoxylin-eosin.WAmus(smooth muscle area),Wamuc(mucous area) and WAi(inner wall area) of the airway were measured and standardized by Pbm(basement membrane perimeter). The areas of collagen Ⅰand Ⅲ in the lung tissue were determined by using a Sirius red-polarizing microscopy morphometry method.Expressions of matrix metalloprotease-9(MMP-9) and tissue inhibitor of metalloproteinase-1(TIMP-1) were detected by immunohistochemistry.RESULTS: WAmus/Pbm,WAmuc/Pbm and WAi/Pbm decreased significantly in CpG ODN and DXM treated group when compared with asthma group(P0.05).No statistical significance between CpG ODN and DXM treated group was observed(P0.05).Collagen deposition in asthma group increased more than that in CpG ODN and DXM treated group(P0.05).The expressions of MMP-9 and TIMP-1 were much higher in asthma group than those in CpG ODN and DXM treated group(P0.05).It had no statistical significance between CpG ODN and DXM treated group(P0.05).CONCLUSION: Airway remodeling occurrs in the chronic asthma.Early intervention with steroid or CpG might partially inhibit its process via lowering expressions of MMP-9 and TIMP-1 in chronic asthma.