RAB AND RHO GTPASES ARE INVOLVED IN SPECIFIC RESPONSE OF PERIODONTAL-LIGAMENT FIBROBLASTS TO MECHANICAL STRETCHING

To investigate the contribution of ras-related signalling molecules to the mechanotransduction process, stretch-sensing human periodontal li gament (PDL) fibroblasts were isolated and cultured in dishes with a f lexible bottom. The cells were stimulated by stretching the bottom of the dishes and membrane fractions were prepared and analysed at the le vel of mapping small GTP-binding proteins by high resolution two-dimen sional gel electrophoresis followed by renaturing transfer and an [alp ha-P-32]GTP-overlay procedure. This analysis revealed that mechanicall y-stretched PDL fibroblasts exhibit complete down-regulation of rhoA a nd induction of rab6, rab17 and a putative member of the rab3 subfamil y in a cell type-specific manner.