Type iia hyperlipoproteinemic sera decrease the synthesis of hyaluronic acid by cultured human aortic smooth muscle cells

Abstract

The synthesis of sulphated glycosaminoglycans (S-GAGs) and hyaluronic acid (HA) by cultured human aortic smooth muscle cells (SMC) was measured in the presence of sera from type IIA hyperlipoproteinemic patients (7 males and 6 females) and their age- and sex-matched controls. Experiments with pooled sera showed that type IIA and control sera differed in their effects on the synthesis of GAGs at high serum concentrations with preincubation times of 24 and 48 h. Therefore, individual sera were tested at 15% with 24 h preincubation. Type IIA sera decreased the synthesis of HA by 21% ( P < 0.001) but had no significant effect on sulphated GAGs. The ratio of sulphated GAGs to HA was higher in the presence of type IIA sera than control sera. The incorporation of thymidine, the number of cells and the amount of DNA did not differ in cultures incubated with type IIA and control sera. Early human and experimental atherosclerotic lesions are known to have an increased sulphated GAGs to HA ratio. Our results suggest that one explanation for the association between type IIA hyperlipoproteinemia and an increased risk for atherosclerosis is the disturbance in the proportions of hyaluronic acid and sulphated GAGs synthesized by arterial SMC.