Response of a co-culture model of epithelial cells and gingival fibroblasts to zoledronic acid

Abstract

Osteonecrosis of the jaw is an adverse effect of bisphosphonates. While the etiopathogenesis of this condition has been investigated, the interactions and effects of bisphosphonates on oral mucosa cells remain unclear. It is hypothesized that cell culture models, such as co-culture or three-dimensional cell culture models, can provide valuable insight. Therefore, the aim of this study was to evaluate the effects of zoledronic acid (ZA) on epithelial cells and gingival fibroblasts in a co-culture model. Briefly, epithelial cells were seeded on transwell inserts and gingival fibroblasts were seeded in the lower well of 24-well plates. The latter were treated with ZA (5 μM) for 24 or 48 h. Cell viability and synthesis of the inflammatory chemokine, CCL2, were subsequently assessed. Data were subjected to statistical analysis with a 5% significance level. In the presence of ZA, the epithelial cells exhibited significant toxicity in both cell culture models and at both time points. However, greater cytotoxicity was observed in the co-culture model. Greater viability for the gingival fibroblasts was also associated with the co-culture model, and ZA-mediated toxicity was observed for the 48 h time point. ZA promoted a significant increase in CCL2 synthesis in both sets of cells, with greater CCL2 synthesis detected in the gingival fibroblasts. However, this effect was diminished in the co-culture model. Taken together, these results confirm the specific response patterns of the cells seeded in the co-culture model and also demonstrate the protective mechanism that is mediated by epithelial/mesenchymal cell interactions upon exposure to ZA.

Synthetic Calcium Phosphate Ceramics as a Potential Treatment for Bisphosphonate-Related Osteonecrosis of the Jaw

“…Predictably, we observed that ZOL significantly decreased the HGF metabolic activity after 72 h of exposure in a manner dependent of the concentration. Earlier studies also showed ZOL cytotoxicity, not only in HGF [37,55,56,57] but also in oral keratinocytes [58,59], epithelial cells, and other cell types [60].…”

Pathogenesis of medication-related osteonecrosis of the jaw: a comparative study of in vivo and in vitro trials

“…Concentrations of 0.01 to 500 μM of zoledronate, 0.01 to 500 μM of pamidronate, 0.01 to 20 μM of alendronate, and 5 to 500 μM of clodronate and ibandronate were used. 108 , 137 – 140 Table 2 summarizes all studies that evaluated fibroblasts in MRONJ.…”

FAK Shutdown: Consequences on Epithelial Morphogenesis and Biomarker Expression Involving an Innovative Biomaterial for Tissue Regeneration

“…Next, the appropriate cell types for our experiments were chosen. We decided to use primary GFs, since they are easy to harvest and cultivate and have been repeatedly shown to support gingival epithelial morphogenesis in vitro [ 63 ]. Immortalization of GFs is possible in principle, especially with human telomerase reverse transcriptase hTERT, but it is interference-prone, and the cells can undergo senescence after only 30–40 passages (own observation) [ 78 , 81 ].…”

“…In the past, cocultures of GFs and gingival keratinocytes (GKs) proved to be valuable tools to establish organotypic epithelial equivalents of the gingival mucosa, which showed protein expression patterns comparable to the native mucosa [ 26 , 27 , 33 , 63 , 64 , 65 ]. Gingival epithelial morphogenesis, differentiation, as well as integrity are in this regard highly dependent on the presence of the fibroblasts.…”