PRGF exerts a cytoprotective role in zoledronic acid-treated oral cells.

Abstract

Bisphosphonates-related osteonecrosis of the jaw (BRONJ) is a common problem in patients undergoing long-term administration of highly potent nitrogen-containing bisphosphonates (N-BPs). This pathology occurs via bone and soft tissue mechanism. Zoledronic acid (ZA) is the most potent intravenous N-BP used to prevent bone loss in patients with bone dysfunction. The objective of this in vitro study was to evaluate the role of different ZA concentrations on the cells from human oral cavity, as well as the potential of plasma rich in growth factors (PRGF) to overcome the negative effects of this BP. Primary human gingival fibroblasts and primary human alveolar osteoblasts were used. Cell proliferation was evaluated by means of a fluorescence-based method. A colorimetric assay to detect DNA fragmentation undergoing apoptosis was used to determine cell death, and the expression of both NF-κB and pNF-κB were quantified by Western blot analysis. ZA had a cytotoxic effect on both human gingival fibroblasts and human alveolar osteoblasts. This BP inhibits cell proliferation, stimulates apoptosis, and induces inflammation. However, the addition of PRGF suppresses all these negative effects of the ZA. PRGF shows a cytoprotective role against the negative effects of ZA on primary oral cells. At present, there is no definitive treatment for bisphosphonates-related osteonecrosis of the jaw (BRONJ), being mainly palliatives. Our results revealed that PRGF has a cytoprotective role in cells exposed to zoledronic acid, thus providing a reliable adjunctive therapy for the treatment of BRONJ pathology.