The role of fructose-1,6-diphosphate in cell migration and proliferation in an in vitro xenograft blood vessel model of vascular wound healing.
Both smooth muscle cells and endothelial cells play an important role in vascular wound healing. To elucidate the role of fructose-1,6-diphosphate, cell proliferation and cell migration studies were performed with human endothelial cells and rat smooth muscle cells. To mimic blood vessels, endothelial and smooth muscle cells were used in 1:10, 1:5, and 1:1 concentrations, respectively, mimicking large-, mid-, and capillary-sized blood vessels. Cell migration was studied with fetal bovine serum-starved cells. For cell proliferation assay, cells were plated at 30-50% confluency and then starved. The cells were incubated for 48 h with fructose-1,6-diphosphate at (per ml) 10 mg, 1 mg, 500 microg, 250 microg, 100 microg, and 10 microg, pulsed with tritiated-thymidine and incubated with 1 N NaOH for 30 min at room temperature, harvested, and counted. For migration assay, confluent cells were starved, wounded, and incubated for 24 h with same concentrations of fructose-1,6-diphosphate as in proliferation assay. The cells were fixed and counted. Smooth muscle cell proliferation was inhibited by fructose-1,6-diphosphate at 10 mg/ml. In the xenograft models of 1:10, 1:5, and 1:1 fructose-1,6-diphosphate inhibited proliferation at 10 mg/ml. In migration studies 10 mg fructose-1,6-diphosphate per ml was inhibitory to both cell types. In large-, mid-, and capillary-sized blood vessels, fructose-1,6-diphosphate inhibited proliferation of both cell types at 10 mg/ml. At the individual cell level, fructose-1,6-diphosphate is nonstimulatory to proliferation of endothelial cells while inhibiting migration, and it acts on smooth muscle cells by inhibiting both proliferation and migration.