Expression of syndecan-1 in rabbit neointima following de-endothelialization by a balloon catheter

Enrichment of proteoglycans is prominent in early atherogenesis, contributing not only to SMC migration and proliferation, but also to low density lipoprotein retention. A family of integral cell membrane proteoglycans termed syndecans has recently been recognized. Among syndecans, syndecan-1, the first isolated member, has received most research attention. In this study, we examined the expression of syndecan-1 in rabbit aorta and aortic neointima, developed in response to a balloon catheter-induced de-endothelialization. The tissues were processed for Northern blot analysis, in situ hybridization, immunohistochemical staining and immunoblotting. Our results indicate that in normal aorta, the signal for syndecan-1 is weak. However, arterial injury induces syndecan-1 expression at both mRNA and protein levels. The presence of syndecan-1 in the neointimal tissue is persistent, prominent even at the 12th week after injury. Syndecan positive cells are distributed in the whole layer of the neointima, but are not visible in the underlying media. The presence of syndecan-1 in arterial neointima suggests a novel means of mediating interactions between neointimal cells and various agents, including extracellular matrix components, growth factors and lipoproteins.