Regulatory role of ginsenoside Rp1, a novel ginsenoside derivative, on CD29-mediated cell adhesion

In this study, we examined the regulatory role of G-Rp1 on cell adhesion events mediated by β1-integrins (CD29). Using a U937 cell-cell adhesion assay, we found that exogenous G-Rp1 downregulates CD29 activation in a dose-dependent manner, whereas G-Rg3 did not cause the same effect. However, G-Rp1 increased cell-fibronectin adhesion comparable to cytochalasin B, an actin cytoskeleton disruptor. Furthermore, G-Rp1 also blocked the rearrangement of actin at sites of cell-cell contact, indicating that the actin cytoskeleton may be a target of G-Rp1 action. Interestingly, G-Rp1 suppressed dephosphorylation of vasodilator-stimulated phosphoprotein (VASP) at Ser-157, known to be an actin cytoskeleton modulatory protein. These results suggest that G-Rp1 may act as a novel regulator of CD29-mediated cell adhesion events, which are involved in numerous pathological symptoms.