Influence of bisphosphonates on oral implantology: Sodium alendronate and zoledronic acid enhance the synthesis and activity of matrix metalloproteinases by gingival fibroblasts seeded on titanium

Naringenin and proanthocyanidins pre-treatment decreases synthesis and activity of gelatinases induced by zoledronic acid in a dental implant surface in vitro model

OBJECTIVE

To assess the effects of pre-treatment with proanthocyanidins (PA) flavonoids, from grape seed extract, and synthetic naringenin (NA) on the synthesis of matrix metalloproteinases (MMPs) gelatinases and their tissue inhibitors (TIMPs), as well as the gelatinolytic activity of MMPs by human gingival fibroblasts (HGF) and osteoblasts (Ob) exposed to zoledronic acid (ZA) in a dental implant surface in vitro model.

DESIGN

The highest non-cytotoxic concentrations of NA and PA were determined for HGF (10 μg/mL; defined by previous study) and Ob (0.5 μg/mL; defined by prestoBlue assay). Then, HFG and Ob were individually seeded onto titanium discs, and after 24 h, cells were pre-treated (or not) with NA or PA, followed (or not) by exposure to ZA. Next, MMP-2, MMP-9, TIMP-1, TIMP-2 synthesis (ELISA), and gelatinolytic activity (in situ zymography) was evaluated. Data were analyzed by one-way ANOVA and Tukey tests (α = 0.05).

RESULTS

ZA treatment increased the synthesis (p < 0.05) and activity of MMPs; flavonoids pre-treatment controlled ZA-induced gelatinolytic effects, down-regulating MMPs synthesis (p < 0.05) and activity by HGF and Ob. For HGF, NA and PA pre-treatment did not up-regulate TIMP synthesis after ZA exposure (p > 0.05); for Ob, TIMP-2 was up-regulated (p < 0.05) by flavonoids, followed by ZA.

CONCLUSIONS

NA and PA pre-treatment provides interesting results in the modulation of ZA deleterious effects, down-regulating MMP-2 and MMP-9 synthesis and activity by HGF and Ob and up-regulating TIMP-2 by Ob.

Chemotherapy drugs and inflammatory cytokines enhance matrix metalloproteinases expression by oral mucosa cells

OBJECTIVE

Oral mucositis (OM), the most common side effect of cancer therapy, is associated with pro-inflammatory cytokines and matrix metalloproteinases (MMPs) increased expression. Although there are approaches for OM management, none is infallible, thus, elucidation of molecular events related to OM etiopathogenesis may improve current therapeutic strategies. This study assessed the influence of pro-inflammatory cytokines and chemotherapy drugs on MMPs expression and synthesis by oral mucosa cells.

DESIGN

Human gingival fibroblasts (HGF) were exposed to different concentrations of methotrexate (MTX) and 5-fluorouracil (5-FU); subsequentially, cell viability, nitric oxide and interleukin(IL)-6 production were evaluated to select the concentration of these drugs that could stimulate inflammatory phenotype without cytotoxic effects. Then, HGF and primary gingival keratinocytes (PGK) were subjected to different stimuli: culture medium (negative control), tumor necrosis factor-alpha (TNF-α - positive control), IL-6, IL-8, MTX, and 5-FU for 3, 6, 12, and 24 h. Next, gene expression and synthesis of MMP-2 and MMP-9 by HGF and MMP-3 by PGK were assessed.

RESULTS

At 6 h, MMP-2 synthesis increased 60 % after exposure to TNF-α and MTX, 40 % after IL-6, and 15 % after IL-8. At 12 h, MMP-9 synthesis increased 15 % after exposure to TNF-α, while MMP-3 synthesis increased 30 % after TNF-α, and 10 % after IL-8. TNF-α-treated groups presented increased gene expression of all MMPs evaluated. IL-8 and 5-FU increased MMP-2 and MMP-3 expression, while IL-6 and MTX augmented MMP-2 expression.

CONCLUSIONS

The chemotherapy drugs and cytokines investigated up-regulated MMPs expression by oral mucosa cells, which may lead to OM establishment and severity.