Rho-Kinase Inhibition Affects Morphology and Migration of Dental Pulp Cells

Objective: To investigate the role of the Rho-GTPase and its downstream target Rho-kinase (ROCK) in morphological characteristic and migration ability of human dental pulp cells (DSCs). Methods: Human DPCs were isolated from one donor and cultured. We studied how the inhibition of ROCK affected human DPCs' morphology by using 10 to 100Mmol/L of Y27632, a Rho-kinase inhibitor, and evaluated visually by confocal laser scanning microscopy (CLSM). Using a transwell chamber system, the migration of human DPCs was examined by using 10Mmol/L of Y27632. The activation of GTP-loaded GTPase was evaluated by GST pull-down assays and western blot analysis. Results: ROCK inhibition led to morphologic and cytoskeleton alterations characterized by an increase in the number and length of cell processes, increased membrane ruffling, and collapse of actin stress fibers. Furthermore, Human DPCs migration was increased by ROCK inhibition (t-test, n=6/gp p<0.01). Using a Rac-GTP pull-down assay and western blot analysis, we showed that Rac1, a member of the Rho family of GTPases, was activated as a consequence of ROCK inhibition. Conclusions: Inhibition of ROCK affects morphological characteristics, the actin microfilamentous system, and cell migration ability of DPCs. These alterations in cell migration are associated with the activation of Rac1.