[Cardiovascular pathology of Marfan syndrome].
In Marfan syndrome, mutations of the fibrillin gene lead to various cardiovascular lesions, such as aortic root dilatation, aortic dissection, and floppy mitral or aortic valve. Disorganization and fragmentation of elastic fibers, characteristic histologic findings of cardiac valves and aortas in Marfan syndrome, are similar to the changes of elastic fibers in non-Marfan dissected aortas and idiopathic floppy valves. Immunohistochemical study using antielastin antibody showed even and diffuse staining pattern in finely disrupted elastic fibers, which could result from either immaturity and incomplete cross-linking or proteolytic damage. Ultrastructurally, decrease of the microfibrils and round-shaped expansion of the amorphous components of elastic fibers were observed. These features, resembled those of the elastic fibers in animals treated with inhibitor of lysyl oxidase, suggest the abnormality of elastogenesis in Marfan syndrome. Recently, the changes in the activity of the matrix metalloproteinases are thought to be responsible for the damage to the elastic fibers in Marfan syndrome. However, these changes are also found in the idiopathic floppy valves. Further investigations are necessary to distinguish the pathogenesis between idiopathic cardiovascular disorders and cardiovascular lesions in Marfan syndrome.
Tamura
Koichi
K
Division of Surgical Pathology, Nippon Medical School Hospital, Tokyo, Japan.
D001011:Aorta / Q000473:pathology / Q000601:surgery; D002319:Cardiovascular System / Q000473:pathology*; D000071837:Fibrillins; D006351:Heart Valves / Q000473:pathology / Q000601:surgery; D006801:Humans; D008382:Marfan Syndrome / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008840:Microfilament Proteins / Q000235:genetics; D009154:Mutation
D000071837:Fibrillins; D008840:Microfilament Proteins; D020782:Matrix Metalloproteinases