Modulation of vascular human endothelial and rat smooth muscle cell growthby a fucosylated chondroitin sulfate from echinoderm

Fucosylated chondroitin sulfate is a glycosaminoglycan extracted from the s ea cucumber Ludwigothurea grisea. This polysaccharide has the same structur e as a mammalian chondroitin sulfate but some of the glucuronic acid residu es display sulfated fucose branches. Anticoagulant and antithrombotic prope rties of fucosylated chondroitin sulfate have already been described. In or der to further investigate its potential(-) therapeutic use as an antithrom botic agent, we studied its effect on vascular smooth muscle cell (SMC) pro liferation and endothelial cell proliferation, migration and Tissue Factor Pathway Inhibitor (TFPI) release. The experiments were performed on SMC fro m rat thoracic aorta and on human umbilical vein endothelial cell (HUVEC) i n culture with or without added fibroblast growth factors (FGF-1 and FGF-2) . Our results showed that: (i) fucosylated chondroitin sulfate had a strong inhibitory effect on SMC proliferation (IC50 = 10 +/- 5 mu g/ml) and (ii) no effect on HWEC proliferation and migration assays, in the absence of exo genous FGF, while heparin had inhibitory effects; (iii) fucosylated chondro itin sulfate (10 mu g/ml) enhanced FGF-1 and FGF-2 induced HUVEC proliferat ion by 45% (145.4 +/- 7.2%) and 27% (126.9 +/- 4.2%), respectively; (iv) on FGF-induced HUVEC migration, fucosylated chondroitin sulfate (10 mu g/ml) had a strong enhancing effect with FGF-1, +122% (222.2 +/- 15.8%), three ti mes higher than that of heparin, and a lower enhancing effect with FGF-2, 43% (142.7 +/- 4.6%), whereas heparin had no effect; (v) fucosylated chondr oitin sulfate stimulated TFPI release, mainly on the free form, +98% (198.2 +/- 25.%). In addition, the structural features of the polysaccharide asso ciated with its biological activity were resolved using chemically modified fucosylated chondroitin sulfates. Sulfated fucose branches groups are esse ntial to the potentiating effect of the polysaccharide on HUVEC proliferati on and migration. Surprisingly, removal of fucose branches from the fucosyl ated chondroitin sulfate did not abolish TFPI release. Finally, partial red uction of the glucuronic acid carboxyl groups limited the potentiating effe ct on HUVEC proliferation and migration but did not affect TFPI release. In conclusion, this fucosylated chondroitin sulfate from invertebrate origin reveals useful properties for an antithrombotic agent: inhibition of SMC pr oliferation, enhancement of endothelium wound repair and TFPI release. Thes e properties on vascular cells, associated with a low bleeding tendency and an antithrombotic activity, strongly suggest its potential use as a new th erapeutic agent in arterial thrombosis and restenosis, with a more favorabl e effect than heparin.