In-vitro-Studie zum Einfluss verschiedener Immunsuppressiva auf Gesamt- und Lebendzellzahl, Zelldurchmesser und Menge an Prokollagen Typ I gingivaler Fibroblasten

Abstract

Due to the decreasing number of organ transplants, their tolerability gains greater significance for affected patients. Therefore, these patients are permanently depended on taking immunosuppressive drugs, which have numerous side effects. One of those side effects most commonly encountered in dental treatment, is gingival enlargement. In this study, we thus analysed the effect of three prevalent immunosuppressants (cyclosporine, tacrolimus and sirolimus) as singular factors on fibroblasts representing the dominant celltype in the gingiva. In order to evaluate the potential of these immunosuppressants, embryonic gingival mice were treated in different concentrations of cyclosporine, tacrolimus and sirolimus. In addition, exposure times were altered and two control groups were applied. In the first step of the present study design, the different concentrations within one immunosuppressant were compared to each other and to the control groups. In a second step, the three immunosuppressants were compared to each other with regard to selected concentrations. In detail, we tested the effect of the immunosuppressants on the number of cells and the viability, the cell diameter and the amount of procollagen type I. Number of cells, viability and cell diameter were explored using the cell counter CASY® Modell TT (Roche Diagnostics GmbH, Roche Applied Science, Penzberg, Deutschland). Procollagen-type- I was determined using an ELISA (Mouse Procollage Type I C-Terminal Propeptide, BlueGene Biotech Co, Shanghai, China). Our results show that sirolimus has a significant negative effect on the number of cells and the viability after an exposure time of 48 and 72 hours (p < 0,05). For cyclosporine and tacrolimus our data indicate no effect on the number of cells and their viability (p > 0,05). The comparison between the three immunosuppressants with regard to selected concentrations revealed a significant difference between the sirolimus group and the two other immunosuppressants after an exposure time of 48 und 72 hours (p < 0,05). The number of cells and the viability of sirolimus treated cells were both significantly lower as compared to the other two immunosuppressants. Comparing cyclosporine treated cells with tacrolimus treated ones, no significant difference was found for both parameters (p > 0,05). The statistical analysis of the cell diameter and procollagen type I rarely showed significant effects. Neither the comparison of different concentrations within one immunosuppressant, nor contrasting the three immunosuppressants for selected concentrations indicated any statistically significant effect. Only the cells treated with 150 ng/Well cyc! 77 losporine showed a significant increase in cell diameter compared with one control group (DMSO-control) after an exposure time of 48 hours (p = 0,0347). Overall, the results do not support the hypothesis assuming a positive effect of the tested immunosuppressants on the number of cells, the viability, the cell diameter and the amount of procollagen type I. In the present study design the immunosuppressants do not show the potential to change embryonic gingival mice fibroblasts leading to the clinical picture of gingival enlargement as singular factors. This may indicate that several different factors are needed to induce gingival enlargement as reflected in the multifactorial model of Seymour and Smith (1991). As a conclusion, future studies should contribute to a better understanding of singular influencing factors on gingival fibroblasts in order to prevent immunocompromised patients from drug-induced gingival enlargement and the resulting consequences for their dental treatment.