Human perlecan immunopurified from different endothelial cell sources has different adhesive properties for vascular cells.

Perlecan, a major heparan sulfate proteoglycan of vascularized tissues, was immunopurified from media conditioned by human endothelial cells of both arterial and venous origin. The heparan sulfate moiety of perlecan from cultured arterial cells differed in amount and/or composition from that produced by a transformed cell line of venous origin. Both forms of perlecan bound basic fibroblast growth factor with Kd approximately 70 nM. In ELISA experiments, perlecan and its protein core bound to various extracellular matrix components in a manner that was strongly influenced by the format of the assay. Human vascular smooth muscle cells and human endothelial cells adhered to perlecan-coated surfaces, and both cell types adhered better to the venous cell-derived than to the arterial cell-derived perlecan. Removal of the heparan sulfate chains abolished this difference and increased the ability of both types of perlecan to adhere vascular cells. Denaturation of perlecan and its protein core also rendered each of them more adhesive, indicating the presence of conformation-independent adhesion determinants in the polypeptide sequence. Their location was investigated using recombinant perlecan domains. Overall, our results represent the first demonstration of human perlecan acting as an adhesive molecule for human vascular cells and suggest that it may play a role in vascular wound healing.