Inhibition of human vascular smooth muscle cell migration and proliferation by beta-cyclodextrin tetradecasulfate

Smooth muscle cell migration and proliferation are important regulatory processes in the development of intimal thickening after vascular injury. beta-cyclodextrin tetradecasulfate, an orally active synthetic heparin mimic, is effective in inhibiting rabbit aortic smooth muscle cell proliferation in vitro and in limiting restenosis in an experimental angioplasty restenosis model in rabbits (Hermann et al., 1993). However, its effects on migration are unknown, as are its effects on human vascular smooth muscle cell biology in general. Using a Transwell assay system, we demonstrated a dose dependent inhibition of human vascular smooth muscle cell random migration for beta-cyclodextrin tetradecasulfate with half maximal inhibition between 100-500 micrograms/ml and 85 +/- 1% inhibition at 10(3) micrograms/ml (P < .001, n = 4). At this latter concentration, inhibition of migration was also demonstrable using a linear under-agarose assay, where the mean velocity for beta-cyclodextrin tetradecasulfate-treated cells (8 +/- 2 microns/h, +/- S.E.) was significantly less than for control cells (21 +/- 4, P < .01), but equaled that of control cells 48 h after drug withdrawal (21 +/- 1, P = NS). Single cell analysis over 17 h using time lapse video microscopy revealed significant inhibition of total migration pathway distance for beta-cyclodextrin tetradecasulfate-treated smooth muscle cells compared with control smooth muscle cells (0.40 +/- 0.03 mm vs. 0.73 +/- 0.03, P < .01). We also demonstrated a dose-dependent inhibition of serum-induced proliferation by beta-cyclodextrin tetradecasulfate in both cultured human umbilical vein and coronary artery smooth muscle cells. To assess whether beta-cyclodextrin tetradecasulfate had any direct cellular toxicity, we measured the release of intracellular LDH at 6 or 24 h. At 10(3) micrograms/ml or less, there was no increase in LDH release compared with untreated cultures. Thus, beta-cyclodextrin tetradecasulfate may be an effective agent in inhibiting intimal thickening after vascular injury by limiting both smooth muscle cell migration and proliferation.