Tumor necrosis factor alpha-induced alteration of glycosaminoglycans in cultured vascular smooth-muscle cells.

We studied alteration of glycosaminoglycans (GAGs) induced by recombinant human tumor necrosis factor alpha (rhTNF alpha) in vascular smooth-muscle cells from bovine aorta in a culture system. It was found that rhTNF alpha at 10 ng/ml and below significantly increased the incorporation of [35S]sulfate (35S) but conversely decreased that of [3H]glucosamine (3H) into GAGs in the trypsinate fraction of the cell layer after a 24-h incubation. These results suggested that rhTNF alpha reduced the formation and/or the anchorage of sugar chains in the cell layer but enhanced their sulfation in whole GAG synthesis by the cells. In results, the ratio of 35S to 3H in the GAGs was markedly increased. This increase occurred after 24 h and longer when the cells were treated with 1.0 ng/ml rhTNF alpha. The TNF alpha-induced alteration of the incorporation of both 35S and 3H was completely blocked by anti-rhTNF alpha antibody. Other cytokines including recombinant human interleukin-1 beta and -6, and platelet-derived growth factor failed to alter the ratio of 35S to 3H in the GAGs of the trypsinate fraction of the cell layer. In cultured vascular endothelial cells from bovine aorta, however, rhTNF alpha at 1.0 ng/ml significantly decreased the incorporation of both 35S and 3H into GAGs of both the trypsinate fraction and the medium; the ratio of 35S to 3H was not changed. Characterization of GAGs in vascular smooth muscle cell trypsinate fraction revealed that rhTNF alpha at 10 ng/ml induced (i) no change of the incorporation of 3H in the hyaluronate fraction, (ii) a marked increase in the incorporation of 35S and no change of that of 3H in chondroitin sulfates (A plus C) fraction, (iii) a significant decrease in the incorporation of both 35S and 3H in the heparan sulfate fraction, and (iv) no change of the incorporation of 35S and a marked decrease in that of 3H in the dermatan sulfate fraction. In the medium, rhTNF alpha also induced various changes of GAGs. It was therefore concluded that TNF alpha may have a capacity of inducing a qualitative change of vascular smooth-muscle cell GAGs, which may be involved in the vascular pathology such as atherosclerosis.