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ERK5 activation is essential for osteoclast differentiation.

Amano S, Chang YT, Fukui Y - PLoS ONE (2015)

Bottom Line: Therefore, activation of ERK5 is required for the induction of c-Fos.These events were confirmed in experiments using M-CSF-dependent bone marrow macrophages.Taken together, the present results show that activation of the MEK5/ERK5 pathway with M-CSF is required for osteoclast differentiation, which may induce differentiation through the induction of c-Fos.

View Article: PubMed Central - PubMed

Affiliation: Division of Microbiology and Immunology, Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Keyakidai, Sakado City, Japan.

ABSTRACT
The MEK/ERK pathways are critical for controlling cell proliferation and differentiation. In this study, we show that the MEK5/ERK5 pathway participates in osteoclast differentiation. ERK5 was activated by M-CSF, which is one of the essential factors in osteoclast differentiation. Inhibition of MEK5 by BIX02189 or inhibition of ERK5 by XMD 8-92 blocked osteoclast differentiation. MEK5 knockdown inhibited osteoclast differentiation. RAW264.7D clone cells, which are monocytic cells, differentiate into osteoclasts after stimulation with sRANKL. ERK5 was activated without any stimulation in these cells. Inhibition of the MEK5/ERK5 pathway by the inhibitors also blocked the differentiation of RAW264.7D cells into osteoclasts. Moreover, expression of the transcription factor c-Fos, which is indispensable for osteoclast differentiation, was inhibited by treatment with MEK5 or ERK5 inhibitors. Therefore, activation of ERK5 is required for the induction of c-Fos. These events were confirmed in experiments using M-CSF-dependent bone marrow macrophages. Taken together, the present results show that activation of the MEK5/ERK5 pathway with M-CSF is required for osteoclast differentiation, which may induce differentiation through the induction of c-Fos.

No MeSH data available.


Related in: MedlinePlus

The formation of TRAP (+) MNCs in 4B12 cells was inhibited by BIX02189 and XMD8-92.(A) 4B12 cells were cultured with 10 ng/ml M-CSF and 10 ng/ml sRANKL in the presence or absence of BIX02189. After 7 days, the cells were fixed and stained to detect TRAP. (B) An experiment similar to A was conducted with XMD8-92. (C) The inhibition of ERK5 (left panel) or ERK1, 2 (right panel) phosphorylation by BIX02189 was examined by Western blot analysis. (D) The cell viabilities during the experiments were analyzed. Cells were incubated with the drugs for one day. Similar results were obtained in three independent experiments.
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pone.0125054.g002: The formation of TRAP (+) MNCs in 4B12 cells was inhibited by BIX02189 and XMD8-92.(A) 4B12 cells were cultured with 10 ng/ml M-CSF and 10 ng/ml sRANKL in the presence or absence of BIX02189. After 7 days, the cells were fixed and stained to detect TRAP. (B) An experiment similar to A was conducted with XMD8-92. (C) The inhibition of ERK5 (left panel) or ERK1, 2 (right panel) phosphorylation by BIX02189 was examined by Western blot analysis. (D) The cell viabilities during the experiments were analyzed. Cells were incubated with the drugs for one day. Similar results were obtained in three independent experiments.

Mentions: As mentioned above, 4B12 cells differentiate into osteoclasts in the presence of M-CSF and sRANKL. We tested the effects of the MEK5/ERK5 pathway inhibitors BIX02189 and XMD8-92 on osteoclast differentiation using 4B12 cells. BIX02189 and XMD8-92 inhibited the formation of TRAP (+) MNCs (Fig 2A and 2B). BIX02189 inhibited the phosphorylation of ERK5 but not of ERK1/2 (Fig 2C). The doses of BIX02189 and XMD8-92 had no effect on the cell viability of 4B12 cells (Fig 2D). As anticipated, TRAP activity in 4B12 cells stimulated with M-CSF and sRANKL was reduced in response to the treatment with BIX02189 or XMD8-92 (Fig 3A and 3B). The TRAP activity was partially inhibited by BIX02189 and was completely inhibited by XMD8-92.


ERK5 activation is essential for osteoclast differentiation.

Amano S, Chang YT, Fukui Y - PLoS ONE (2015)

The formation of TRAP (+) MNCs in 4B12 cells was inhibited by BIX02189 and XMD8-92.(A) 4B12 cells were cultured with 10 ng/ml M-CSF and 10 ng/ml sRANKL in the presence or absence of BIX02189. After 7 days, the cells were fixed and stained to detect TRAP. (B) An experiment similar to A was conducted with XMD8-92. (C) The inhibition of ERK5 (left panel) or ERK1, 2 (right panel) phosphorylation by BIX02189 was examined by Western blot analysis. (D) The cell viabilities during the experiments were analyzed. Cells were incubated with the drugs for one day. Similar results were obtained in three independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401765&req=5

pone.0125054.g002: The formation of TRAP (+) MNCs in 4B12 cells was inhibited by BIX02189 and XMD8-92.(A) 4B12 cells were cultured with 10 ng/ml M-CSF and 10 ng/ml sRANKL in the presence or absence of BIX02189. After 7 days, the cells were fixed and stained to detect TRAP. (B) An experiment similar to A was conducted with XMD8-92. (C) The inhibition of ERK5 (left panel) or ERK1, 2 (right panel) phosphorylation by BIX02189 was examined by Western blot analysis. (D) The cell viabilities during the experiments were analyzed. Cells were incubated with the drugs for one day. Similar results were obtained in three independent experiments.
Mentions: As mentioned above, 4B12 cells differentiate into osteoclasts in the presence of M-CSF and sRANKL. We tested the effects of the MEK5/ERK5 pathway inhibitors BIX02189 and XMD8-92 on osteoclast differentiation using 4B12 cells. BIX02189 and XMD8-92 inhibited the formation of TRAP (+) MNCs (Fig 2A and 2B). BIX02189 inhibited the phosphorylation of ERK5 but not of ERK1/2 (Fig 2C). The doses of BIX02189 and XMD8-92 had no effect on the cell viability of 4B12 cells (Fig 2D). As anticipated, TRAP activity in 4B12 cells stimulated with M-CSF and sRANKL was reduced in response to the treatment with BIX02189 or XMD8-92 (Fig 3A and 3B). The TRAP activity was partially inhibited by BIX02189 and was completely inhibited by XMD8-92.

Bottom Line: Therefore, activation of ERK5 is required for the induction of c-Fos.These events were confirmed in experiments using M-CSF-dependent bone marrow macrophages.Taken together, the present results show that activation of the MEK5/ERK5 pathway with M-CSF is required for osteoclast differentiation, which may induce differentiation through the induction of c-Fos.

View Article: PubMed Central - PubMed

Affiliation: Division of Microbiology and Immunology, Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Keyakidai, Sakado City, Japan.

ABSTRACT
The MEK/ERK pathways are critical for controlling cell proliferation and differentiation. In this study, we show that the MEK5/ERK5 pathway participates in osteoclast differentiation. ERK5 was activated by M-CSF, which is one of the essential factors in osteoclast differentiation. Inhibition of MEK5 by BIX02189 or inhibition of ERK5 by XMD 8-92 blocked osteoclast differentiation. MEK5 knockdown inhibited osteoclast differentiation. RAW264.7D clone cells, which are monocytic cells, differentiate into osteoclasts after stimulation with sRANKL. ERK5 was activated without any stimulation in these cells. Inhibition of the MEK5/ERK5 pathway by the inhibitors also blocked the differentiation of RAW264.7D cells into osteoclasts. Moreover, expression of the transcription factor c-Fos, which is indispensable for osteoclast differentiation, was inhibited by treatment with MEK5 or ERK5 inhibitors. Therefore, activation of ERK5 is required for the induction of c-Fos. These events were confirmed in experiments using M-CSF-dependent bone marrow macrophages. Taken together, the present results show that activation of the MEK5/ERK5 pathway with M-CSF is required for osteoclast differentiation, which may induce differentiation through the induction of c-Fos.

No MeSH data available.


Related in: MedlinePlus