Hydrogen peroxide induces G2 cell cycle arrest and inhibits cell proliferation in osteoblasts.
Anat Rec (Hoboken)
; 292(8): 1107-13, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-19645015
ABSTRACT
Reactive oxygen species (ROSs) are involved in osteoporosis by inhibiting osteoblastic differentiation and stimulating osteoclastgenesis. Little is known about the role and how ROS controls proliferation of osteoblasts. Mammalian target of rapamycin, mTOR, is a central regulator of cell growth and proliferation. Here, we report for the first time that 5-200 microM hydrogen peroxide (H(2)O(2)) dose- and time-dependently suppressed cell proliferation without affecting cell viability in mouse osteoblast cell line, MC3T3-E1, and in human osteoblast-like cell line, MG63. Further study revealed that protein level of cyclin B1 decreased markedly and the percentage of the cells in G(2)/M phase increased about 2-4 fold by 200 microM H(2)O(2) treatment for 24-72 hr. A total of 0.5-5 mM of H(2)O(2) but not lower concentrations (5-200 microM) of H(2)O(2) inhibited mTOR signaling, as manifested by dephosphorylation of S6K (T389), 4E-BP1 (T37/46), and S6(S235/236) in MC3T3-E1 and MG63 cells. Rapamycin, which could inhibit mTOR signaling and cell proliferation, however, did not reduce the protein level of cyclin B1. In a summary, H(2)O(2) prevents cell proliferation of osteoblasts by down-regulating cyclin B1 and inducing G(2) cell cycle arrest. Inhibition of mTOR signaling by H(2)O(2) may not be involved in this process.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Osteoblastos
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Ciclo Celular
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Fase G2
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Proliferação de Células
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Peróxido de Hidrogênio
Limite:
Animals
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Humans
Idioma:
En
Revista:
Anat Rec (Hoboken)
Assunto da revista:
ANATOMIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
China