Effects of zoledronic acid on odontoblast-like cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of the study was to evaluate the effects of a highly potent bisphosphonate, zoledronic acid (ZOL), on cultured odontoblast-like cells MDPC-23. The cells (1.5 x 10(4) cells/cm(2)) were seeded for 48 h in wells of 24-well dished. Then, the plain culture medium (DMEM) was replaced by fresh medium without fetal bovine serum. After 24 h, ZOL (1 or 5 mu M) was added to the medium and maintained in contact with the cells for 24 h. After this period, the succinic dehydrogenase (SDH) enzyme production (cell viability - MTT assay), total protein (TP) production, alkaline phosphatase (ALP) activity, and gene expression (qPCR) of collagen type I (Col-I) and ALP were evaluated. Cell morphology was assessed by SEM. Five mu M ZOL caused a significant decrease in SDH production. Both ZOL concentrations caused a dose-dependent significant decrease in TP production and ALP activity. ZOL also produced discret morphological alterations in the MDPC-23 cells. Regarding gene expression, 1 mu M ZOL caused a significant increase in Col-I expression. Although 5 mu M ZOL did not affect Col-I expression, it caused a significant alteration in ALP expression (ANOVA and Tukey's test, p < 0.05). ZOL presented a dose-dependent cytotoxic effect on the odontoblast-like cells, suggesting that under clinical conditions the release of this drug from dentin could cause damage to the pulpo-dentin complex. (C) 2012 Elsevier Ltd. All rights reserved.585467473Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/54722-1, BP DR 2009/52326-1]FAPESP [2009/54722-1, BP.DR: 2009/52326-1]CNPq [301291/2010-1

Zoledronic acid decreases gene expression of vascular endothelial growth factor and basic fibroblast growth factor by human epithelial cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Delayed wound healing in patients taking bisphosphonates could result from decreased expression of growth factors, which are directly related to cell proliferation and migration. In this study, we evaluated the gene expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bEGF) by epithelial cells exposed to zoledronic acid 5 mu mol for 48 h using real-time polymerase chain reaction. The gene expression of VEGF and bFGF by epithelial cells exposed to zoledronic acid decreased by 34% and 51%, respectively (p=0.0001 and p=0.0001). We conclude that zoledronic acid can decrease the expression of growth factors by epithelial cells. (C) 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.518971973Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/54722-1, BP.DR: 2009/52326-1]CNPq [301029/2010-1

Zoledronic Acid Inhibits Human Osteoblast Activities

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Bisphosphonates are potent inhibitors of bone resorption. These kinds of drugs, which are used for the treatment of osteolytic diseases, have been associated with the occurrence of oral osteonecrosis, especially in patients over 60 years old. Current studies have demonstrated that the cytotoxic effects of bisphosphonates on osteoblasts play an important role in oral osteonecrosis development. Objective:The aim of this study was to evaluate the effect of long-term application of a highly potent bisphosphonate - zoledronic acid (ZA) - on human osteoblasts in vitro. Methods: Human osteoblasts (MG63 cell line) were seeded for 72 h in wells of 24-well plates. The Dulbecco's modified Eagle's medium (DMEM) was then replaced by culture medium without fetal bovine serum (FBS), and the cells were incubated for an additional 24 h, after which ZA was added to the DMEM without FBS and incubated in contact with osteoblasts for 7, 14 or 21 days. Cell viability (CV), total protein production (TPP), alkaline phosphatase (ALP) activity, mineral nodule formation (MNF), and gene expression of ALP and osteocalcin (OCN), as well as cell morphology by scanning electronic microscopy, were evaluated. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests, with a significance level of 5%. Results:The cytotoxic effects of ZA on osteoblasts were characterized by reduction of CV, TPP, ALP and MNF production. In addition, ZA MNF caused a decrease in gene expression of ALP and OCN, as well as intense cell morphology alterations. All these negative effects of ZA were concentration and period dependent. Conclusion: Both concentrations of ZA (1 and 5 mu m) caused cytotoxic effects to osteoblasts which reduced the production and expression of proteins that play an important role in bone matrix synthesis and mineralization. (C) 2013 S. Karger AG, Basel596534541Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/54722-1, BP.DR: 2009/52326-1]CNPq [301291/2010-1

Biostimulatory effects of low-level laser therapy on epithelial cells and gingival fibroblasts treated with zoledronic acid

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Low-level laser therapy (LLLT) has been considered as an adjuvant treatment for bisphosphonate-related osteonecrosis, presenting positive clinical outcomes. However, there are no data regarding the effect of LLLT on oral tissue cells exposed to bisphosphonates. This study aimed to evaluate the effects of LLLT on epithelial cells and gingival fibroblasts exposed to a nitrogen-containing bisphosphonate-zoledronic acid (ZA). Cells were seeded in wells of 24-well plates, incubated for 48 h and then exposed to ZA at 5 mu M for an additional 48 h. LLLT was performed with a diode laser prototype-LaserTABLE (InGaAsP-780 nm +/- 3 nm, 25 mW), at selected energy doses of 0.5, 1.5, 3, 5, and 7 J cm(-2) in three irradiation sessions, every 24 h. Cell metabolism, total protein production, gene expression of vascular endothelial growth factor (VEGF) and collagen type I (Col-I), and cell morphology were evaluated 24 h after the last irradiation. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney tests at 5% significance. Selected LLLT parameters increased the functions of epithelial cells and gingival fibroblasts treated with ZA. Gene expression of VEGF and Col-I was also increased. Specific parameters of LLLT biostimulated fibroblasts and epithelial cells treated with ZA. Analysis of these in vitro data may explain the positive in vivo effects of LLLT applied to osteonecrosis lesions.235Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/54722-1, BP.DR 2009/52326-1]CNPq [301029/2010-1