IADR Abstract Archives
Comparison of Two Controls Used in WAB In-vitro Experiments
Objectives: In vitro weight approach based (WAB) loading models have been used for years to elucidate molecular mechanisms of bone remodelling during orthodontic tooth movement. In this model, static compression (CF) is applied by loading cells with a cylinder filled with lead granules placed on a glass-coverslip to assure even force distribution. Two different types of the negative controls have been described in the studies: conventional controls with unloaded cells (CC) and controls with cells covered with a glass-coverslip (GC). Aim of this study was to investigate potential differences between both negative controls concerning cell viability, cell proliferation and gene expression.
Methods: Human primary periodontal ligament fibroblasts were cultured unloaded (CC) or covered with a glass-coverslip only (GC) for 1-6 days. On each day gene expression of cFOS, IL6, and COX2, was examined by qPCR and PGE2 concentrations were measured using ELISA (n=6). The independent-samples Mann-Whitney U test was applied to test significant differences between CC and GC. Cell growth and cell viability were monitored daily.
Results: Increased expression of cFOS (p≤0.016) and COX2 (p≤0.026) was observed in GC group during whole experiment when compared to CC. IL6 in GC showed increased expression on the days 1-3 and 5 (p≤0.010). PGE2 was found at higher concentrations in GC than in CC in all timepoints. Cells viability maintained throughout the experiment in both groups. However, proliferation rate in GC was significantly lower.
Conclusions: Our results show an increased expression of the genes and metabolites related to the mechanosensing (cFOS) and bone remodelling (IL6, COX2, PGE2) in the GC group. We suppose, that the observed differences in gene expression between GC and CC, as well as the differences in the cell proliferation might be related to mechanical stimuli originating from the glass-coverslip. The exact origin and magnitude of this stimuli remains unclear, therefore further examination is required.
Methods: Human primary periodontal ligament fibroblasts were cultured unloaded (CC) or covered with a glass-coverslip only (GC) for 1-6 days. On each day gene expression of cFOS, IL6, and COX2, was examined by qPCR and PGE2 concentrations were measured using ELISA (n=6). The independent-samples Mann-Whitney U test was applied to test significant differences between CC and GC. Cell growth and cell viability were monitored daily.
Results: Increased expression of cFOS (p≤0.016) and COX2 (p≤0.026) was observed in GC group during whole experiment when compared to CC. IL6 in GC showed increased expression on the days 1-3 and 5 (p≤0.010). PGE2 was found at higher concentrations in GC than in CC in all timepoints. Cells viability maintained throughout the experiment in both groups. However, proliferation rate in GC was significantly lower.
Conclusions: Our results show an increased expression of the genes and metabolites related to the mechanosensing (cFOS) and bone remodelling (IL6, COX2, PGE2) in the GC group. We suppose, that the observed differences in gene expression between GC and CC, as well as the differences in the cell proliferation might be related to mechanical stimuli originating from the glass-coverslip. The exact origin and magnitude of this stimuli remains unclear, therefore further examination is required.