Effects of tacrolimus on morphology, proliferation and differentiation of mesenchymal stem cells derived from gingiva tissue

Tacrolimus is a 23-membered macrolide lactone with potent immunosuppressive activity that is effective in the prophylaxis of organ rejection following kidney, heart and liver transplantation. Tacrolimus also exerts a variety of actions on bone metabolism. The aim of the present study was to evaluate the effects of different concentrations of tacrolimus on the morphology and viability of human stem cells derived from the gingiva. Gingival-derived stem cells were grown in the presence of tacrolimus at final concentrations ranging from 0.001 to 100 mu g/ml. The morphology of the cells was viewed under an inverted microscope and the cell viability was analyzed using Cell Counting kit-8 (CCK-8) on days 1, 3, 5 and 7. Alizarin Red S staining was used to assess mineralization of treated cells. The control group showed spindle-shaped, fibroblast-like morphology and the shapes of the cells in 0.001, 0.01, 0.1, 1 and 10 mu g/ml tacrolimus were similar to those of the control group. All groups except the 100 mu g/ml group showed increased cell proliferation over time. Cultures grown in the presence of tacrolimus at 0.001, 0.01, 0.1, 1 and 10 mu g/ml were not identified to be significantly different compared with the control at days 1, 3 and 5 using the CCK-8 assays. Increased mineralized deposits were noted with increased incubation time. Treatment with tacrolimus from 0.001 to 1 mu g/ml led to an increase in mineralization compared with the control group. Within the limits of this study, tacrolimus at the tested concentrations (ranging from 0.001 to 10 mu g/ml) did not result in differences in the viability of stem cells derived from gingiva; however it did enhance osteogenic differentiation of the stem cells.