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Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages.

Nabeshi H, Yoshikawa T, Akase T, Yoshida T, Tochigi S, Hirai T, Uji M, Ichihashi K, Yamashita T, Higashisaka K, Morishita Y, Nagano K, Abe Y, Kamada H, Tsunoda S, Itoh N, Yoshioka Y, Tsutsumi Y - Nanoscale Res Lett (2011)

Bottom Line: The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects.Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles.These results indicated that nSP did not cause differentiation of osteoclasts.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. tomoaki@phs.osaka-u.ac.jp.

ABSTRACT
Amorphous silica nanoparticles (nSP) have been used as a polishing agent and/or as a remineralization promoter for teeth in the oral care field. The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects. Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles. However, tartrate-resistant acid phosphatase (TRAP) activity and the number of osteoclast cells (TRAP-positive multinucleated cells) were not changed by nSP treatment in the presence of receptor activator of nuclear factor κB ligand (RANKL) at doses that did not induce cytotoxicity by silica particles. These results indicated that nSP did not cause differentiation of osteoclasts. Collectively, the results suggested that nanosilica exerts no effect on RANKL-induced osteoclast differentiation of RAW264.7 cells, although a detailed mechanistic examination of the nSP70-mediated cytotoxic effect is needed.

No MeSH data available.


Related in: MedlinePlus

Effect of silica particles on the RANKL-induced TRAP activity in RAW264.7 cells. RAW264.7 cells were incubated with 10 μg/ml silica particles and 30 ng/ml RANKL for 5 days. TRAP activity was calculated relative to the negative controls (medium without RANKL). Data are expressed as the mean ± SD (n = 3).
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Figure 2: Effect of silica particles on the RANKL-induced TRAP activity in RAW264.7 cells. RAW264.7 cells were incubated with 10 μg/ml silica particles and 30 ng/ml RANKL for 5 days. TRAP activity was calculated relative to the negative controls (medium without RANKL). Data are expressed as the mean ± SD (n = 3).

Mentions: In order to investigate the effects of nanosilica on osteoclast differentiation in RAW264.7 cells, TRAP activity, which is a known indicator of osteoclast differentiation, was measured. TRAP activity levels of RANKL (which is a key molecule in osteoclast differentiation)-treated RAW264.7 cells were significantly increased compared to non-treated RAW264.7 cells (Figure 2). On the other hand, TRAP activity levels of RAW264.7 cells treated with RANKL and silica particles were almost equal to those of cells treated with RANKL alone. An analysis comparing TRAP activities between nSP70, nSP300 and mSP1000 did not reveal significant size-dependent changes (Figure 2). Furthermore, the number of TRAP-positive multinucleated cells were tallied as a measure of osteoclast differentiation by RANKL and silica particle treatment. As a result of TRAP staining, RAW264.7 cells treated by RANKL alone or by RANKL with silica particles were almost all TRAP positive (Figure 3). The number of TRAP-positive multinucleated cells indicated no significant differences following each silica particle treatment, although nSP70-treated RAW264.7 cells tended to have an increased number of TRAP-positive multinucleated cells compared to cells treated with RANKL alone (Figure 4). These results suggested that none of the silica particle sizes used in this study induced effects on osteoclast differentiation of RAW264.7 cells at the doses given.


Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages.

Nabeshi H, Yoshikawa T, Akase T, Yoshida T, Tochigi S, Hirai T, Uji M, Ichihashi K, Yamashita T, Higashisaka K, Morishita Y, Nagano K, Abe Y, Kamada H, Tsunoda S, Itoh N, Yoshioka Y, Tsutsumi Y - Nanoscale Res Lett (2011)

Effect of silica particles on the RANKL-induced TRAP activity in RAW264.7 cells. RAW264.7 cells were incubated with 10 μg/ml silica particles and 30 ng/ml RANKL for 5 days. TRAP activity was calculated relative to the negative controls (medium without RANKL). Data are expressed as the mean ± SD (n = 3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211885&req=5

Figure 2: Effect of silica particles on the RANKL-induced TRAP activity in RAW264.7 cells. RAW264.7 cells were incubated with 10 μg/ml silica particles and 30 ng/ml RANKL for 5 days. TRAP activity was calculated relative to the negative controls (medium without RANKL). Data are expressed as the mean ± SD (n = 3).
Mentions: In order to investigate the effects of nanosilica on osteoclast differentiation in RAW264.7 cells, TRAP activity, which is a known indicator of osteoclast differentiation, was measured. TRAP activity levels of RANKL (which is a key molecule in osteoclast differentiation)-treated RAW264.7 cells were significantly increased compared to non-treated RAW264.7 cells (Figure 2). On the other hand, TRAP activity levels of RAW264.7 cells treated with RANKL and silica particles were almost equal to those of cells treated with RANKL alone. An analysis comparing TRAP activities between nSP70, nSP300 and mSP1000 did not reveal significant size-dependent changes (Figure 2). Furthermore, the number of TRAP-positive multinucleated cells were tallied as a measure of osteoclast differentiation by RANKL and silica particle treatment. As a result of TRAP staining, RAW264.7 cells treated by RANKL alone or by RANKL with silica particles were almost all TRAP positive (Figure 3). The number of TRAP-positive multinucleated cells indicated no significant differences following each silica particle treatment, although nSP70-treated RAW264.7 cells tended to have an increased number of TRAP-positive multinucleated cells compared to cells treated with RANKL alone (Figure 4). These results suggested that none of the silica particle sizes used in this study induced effects on osteoclast differentiation of RAW264.7 cells at the doses given.

Bottom Line: The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects.Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles.These results indicated that nSP did not cause differentiation of osteoclasts.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. tomoaki@phs.osaka-u.ac.jp.

ABSTRACT
Amorphous silica nanoparticles (nSP) have been used as a polishing agent and/or as a remineralization promoter for teeth in the oral care field. The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects. Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles. However, tartrate-resistant acid phosphatase (TRAP) activity and the number of osteoclast cells (TRAP-positive multinucleated cells) were not changed by nSP treatment in the presence of receptor activator of nuclear factor κB ligand (RANKL) at doses that did not induce cytotoxicity by silica particles. These results indicated that nSP did not cause differentiation of osteoclasts. Collectively, the results suggested that nanosilica exerts no effect on RANKL-induced osteoclast differentiation of RAW264.7 cells, although a detailed mechanistic examination of the nSP70-mediated cytotoxic effect is needed.

No MeSH data available.


Related in: MedlinePlus