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Published on: January 30, 2018
Mineral trioxide aggregate (MTA) inhibits osteoclastogenesis and osteoclast activation through calcium and aluminum
Taia Maria Berto Rezende1,2,3, Antônio Paulino Ribeiro Sobrinho4, Leda Quercia Vieira5
1Programa de Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil. taiambr@gmail.com.
Objective:
To evaluate the effect(s) of mineral trioxide aggregate (MTA) on in vitro RANKL-mediated osteoclast-dependent bone resorption events and the influence of Ca2+ and Al3+ on the osteoclastogenesis inhibition by MTA.
Materials And Methods:
Two types of osteoclast precursors, RAW 264.7 (RAW) cell line or bone marrow cells (obtained from BALB/c mice and stimulated with recombinant (r) macrophage colony stimulation factor (M-CSF), were stimulated with or without recombinant (r) activator of nuclear kappa B ligand (RANKL), in the presence or absence of MTA for 6 to 8 days. White Angelus MTA and Bios MTA (Angelus, Londrina, Paraná, Brazil) were prepared and inserted into capillary tubes (direct contact surface = 0.50 mm2 and 0.01 mm2). Influence of MTA on these types of osteoclast precursors was measured by the number of differentiated tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (RAW and bone marrow cells), TRAP enzyme activity (RAW cells), cathepsin K gene expression (RAW cells), and resorptive pit formation (RAW cells) by mature osteoclasts. Besides, RAW cells were also stimulated with Ca2+ and Al3+ to evaluate the influence of these ions on MTA anti-osteoclastogenic potential.
Results:
In bone marrow and RAW cells, the number of TRAP-positive mature osteoclast cells induced by rRANKL was significantly inhibited by the presence of MTA compared with control rRANKL stimulation without MTA (p < 0.05), along with the reduction of TRAP enzyme activity (p < 0.05) and the low expression of cathepsin K gene (p < 0.05). In contrast, to control mature osteoclasts, the resorption area on dentin was significantly decreased for mature osteoclasts incubated with MTA (p < 0.05). rRANKL-stimulated RAW cells treated with Ca2+ and Al3+ decreased the number of osteoclasts cells. Besides, the aluminum oxide was the dominant suppressor of the osteoclastogenesis process.
Conclusions:
MTA significantly suppressed RANKL-mediated osteoclastogenesis and osteoclast activity and, therefore, appears able to suppress bone resorption events in periapical lesions. This process might be related to Ca2+ and Al3+ activities.
Clinical Relevance:
MTA is an important worldwidely acknowleged biomaterial. The knowledge about its molecular activities on osteoclasts might contribute to improving the understanding of its clinical efficacy.
Insights
Mineral trioxide aggregate (MTA) inhibits osteoclast formation and activity, suggesting it can reduce bone resorption in periapical lesions. Calcium and aluminum ions may contribute to MTA's anti-osteoclastogenic effects.
Area of Science:
- Biomaterials Science
- Cell Biology
- Oral Biology
Background:
- Mineral trioxide aggregate (MTA) is a widely used biomaterial in endodontics.
- Osteoclast-dependent bone resorption is a key process in periapical lesions.
Purpose of the Study:
- To investigate the in vitro effects of MTA on osteoclast-mediated bone resorption.
- To determine the influence of calcium (Ca2+) and aluminum (Al3+) ions on MTA's inhibition of osteoclastogenesis.
Main Methods:
- Osteoclast precursors (RAW 264.7 cell line and mouse bone marrow cells) were stimulated with RANKL in the presence or absence of MTA.
- Assays included TRAP-positive multinuclear cell counting, TRAP enzyme activity, cathepsin K gene expression, and resorptive pit formation.
- RAW cells were also treated with Ca2+ and Al3+ to assess their impact on MTA's anti-osteoclastogenic potential.
Main Results:
- MTA significantly inhibited RANKL-induced osteoclast differentiation and activity, reducing TRAP-positive cells, TRAP enzyme activity, and cathepsin K expression.
- MTA significantly decreased the resorption area on dentin by mature osteoclasts.
- Calcium and aluminum ions reduced osteoclast numbers, with aluminum oxide being a dominant suppressor of osteoclastogenesis.
Conclusions:
- MTA effectively suppresses RANKL-mediated osteoclastogenesis and activity, indicating its potential to inhibit bone resorption in periapical lesions.
- The anti-osteoclastogenic effects of MTA may be attributed to the actions of Ca2+ and Al3+ ions.
- Understanding MTA's molecular mechanisms on osteoclasts can enhance comprehension of its clinical efficacy.
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