DIFFERENTIAL-EFFECTS OF FIBRONECTIN-DERIVED OLIGOPEPTIDES ON THE ATTACHMENT OF RABBIT LENS EPITHELIAL-CELLS IN-VITRO

Among the Arg-Gly-Asp (RGD)-containing sequences that are known to be cell-binding domains of fibronectin, 500 mu g/ml of Arg-Gly-Asp-Ser (R GDS) and Gly-Arg-Gly-Asp-Ser showed 100% inhibition of the attachment of cultured lens epithelial cells (TOTL-86 cells), when they were adde d to culture medium and coincubated with the cells for 24 h whereas RG D at concentrations of 500, 1,000 and 2,000 mu g/ml had no such activi ty. After 48 h of cocultivation of 800, 400 or 200 mu g/ml of RGDS wit h TOTL-86 cells, the percentage of floating cells was 100, 30.1 or 11. 1%, respectively. After 144 h of cocultivation with RGDS, the percenta ge of floating cells was 1.6, 2.4 or 1.9%, respectively, indicating th at RGDS was not cytotoxic to lens epithelial cells. However, replacing the medium with fresh medium containing new RGDS peptide resulted in floating of cells. We also studied the inhibitory effect of two other amino acid sequences that are found in cell-binding sites of the fibro nectin molecule: Glu-Ile-Leu-Asp-Val-Pro-Ser-Thr (EILDVPST) and Arg-Gl u-Asp-Val (REDV). At 500 and 1,000 mu g/ml, respectively, neither EILD VPST nor REDV has an inhibitory effect on the attachment of TOTL-86 ce lls, while RGDS at a concentration of 500 mu g/ml completely inhibited the attachment of the cells in 24 h of incubation.