The expression and significance of metalloproteinase in the calciflc aortic valve / 中国综合临床

ABSTRACT

Objective To study the expression and significance of metalloproteinase 2(MMP-2)and tisse inhibitor of metalloproteinase(TIMP-2 ) in the degenerative calcific aortic valve.Methods 15 calcific and 10 non-calcific aortic valve acquired through aortic valve replacement.were studied by immunohistochemistry for MMP-2 and TIMP-2.Morphologic changes were observed by light and transmission electron microscopic.Results The expression of MMP-2 and TIMP-2 in calcific group were significantly higher than in non-calcific group(P<0.01).Positive cells were mostly localized subendothelial and the extracellular matrix.Control valves exhibited very weak staining of MMP-2 and TIMP-2 mostly localized in the extracelluar matrix.Various degree of endothelial damage and interstitial calcification were observed.Conculsion The expression of MMP-2 and TIMP-2 may play an important role in the calcific aortic valve.They may be involved not only in matrix degradation but also in matrix remodeling.The mecha-nism of regulation and activation remain to be elucidated.