[Involvement of heparanase in human abdominal aortic aneurysm].
ABSTRACT To determine whether heparanase might participate the formation of abdominal aortic aneurysms (AAA) and explore a novel pathogenesis for it.
Total RNA was extracted from 20 tissue samples of human infrarenal abdominal aortic aneurysm (AAA) and 5 samples of normal aorta (NA), all resected in operation, and 5 samples of primary hepatocellular carcinoma. Northern blot was used to evaluate the expression of heparanase. Immunohistochemistry and computer-assisted image analysis were used to assess the expression of heparanase and its substrate heparan sulfate proteoglycan protein (HSGP) and microvessel hyperplasia.
Semi-quantitative analysis showed that the expression of heparanase in AAA was significantly higher than that in normal abdominal aorta (P < 0.01), but equivalent to that in primary hepatocellular carcinoma (P > 0.05). However, the expression of HSPG was lowered in AAA and was significantly negatively correlated with the expression of heparanase and microvessel density. Both of heparanase and HSPG were mainly located in adventitia and intima of AAA walls.
Heparanase participates in the structure damage and remodeling of abdominal aorta at matrix level, which contributes to AAA formation.