Low-level laser irradiation enhances BMP-induced osteoblast differentiation by stimulating the BMP/Smad signaling pathway

Shizu Hirata, Chiaki Kitamura, Hidefumi Fukushima, Ikuo Nakamichi, Yoshimitsu Abiko, Masamichi Terashita, Eijiro Jimi

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Low-level laser irradiation (LLLI) has been shown to induce bone formation and osteoblast differentiation both in vivo and in vitro. However, the molecular mechanism by which LLLI stimulates osteoblast differentiation is still unclear. The aim of the present study was to examine whether Ga-Al-As laser irradiation could enhance BMP2-induced alkaline phosphatase (ALP) activity in C2C12 cells. Laser irradiation at 0.5 W for 20 min enhanced BMP2-induced ALP activity. Laser treatment alone did not affect ALP activity. To exclude the effect of pH or temperature changes during irradiation, we shortened the exposure time to 2 min, with various levels of laser power. At 2.5 W, irradiation stimulated BMP2-induced ALP activity but not cell proliferation, whereas 1 or 5 W laser power did not induce any significant effects. Irradiation stimulated BMP2-induced phosphorylation of Smad1/5/8 and BMP2 expression, but had no effect on the expression of inhibitory Smads 6 and 7, BMP4, or insulin-like growth factor 1. Laser irradiation enhanced Smad-induced Id1 reporter activity as well as expression of bone morphogenetic protein (BMP)-induced transcription factors such as Id1, Osterix, and Runx2. Laser irradiation also stimulated BMP-induced expressions of type I collagen, osteonectin, and osteocalcin mRNA, markers of osteoblasts. This enhancement of BMP2-induced ALP activity and Smad phosphorylation by laser irradiation was also observed in primary osteoblasts. These results suggest that LLLI accelerates the differentiation of BMP-induced osteoblasts by stimulating the BMP/Smad signaling pathway.

Original languageEnglish
Pages (from-to)1445-1452
Number of pages8
JournalJournal of Cellular Biochemistry
Volume111
Issue number6
DOIs
Publication statusPublished - Dec 15 2010

Fingerprint

Bone Morphogenetic Proteins
Osteoblasts
Laser beam effects
Lasers
Alkaline Phosphatase
Phosphorylation
Irradiation
Osteonectin
Osteocalcin
Cell proliferation
Somatomedins
Collagen Type I
Bone
Transcription Factors
Osteogenesis
Messenger RNA
Cell Proliferation

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Low-level laser irradiation enhances BMP-induced osteoblast differentiation by stimulating the BMP/Smad signaling pathway. / Hirata, Shizu; Kitamura, Chiaki; Fukushima, Hidefumi; Nakamichi, Ikuo; Abiko, Yoshimitsu; Terashita, Masamichi; Jimi, Eijiro.

In: Journal of Cellular Biochemistry, Vol. 111, No. 6, 15.12.2010, p. 1445-1452.

Research output: Contribution to journalArticle

Hirata, Shizu ; Kitamura, Chiaki ; Fukushima, Hidefumi ; Nakamichi, Ikuo ; Abiko, Yoshimitsu ; Terashita, Masamichi ; Jimi, Eijiro. / Low-level laser irradiation enhances BMP-induced osteoblast differentiation by stimulating the BMP/Smad signaling pathway. In: Journal of Cellular Biochemistry. 2010 ; Vol. 111, No. 6. pp. 1445-1452.
@article{2d7ef1d80b9243bd95adc9d2c5a69d8d,
title = "Low-level laser irradiation enhances BMP-induced osteoblast differentiation by stimulating the BMP/Smad signaling pathway",
abstract = "Low-level laser irradiation (LLLI) has been shown to induce bone formation and osteoblast differentiation both in vivo and in vitro. However, the molecular mechanism by which LLLI stimulates osteoblast differentiation is still unclear. The aim of the present study was to examine whether Ga-Al-As laser irradiation could enhance BMP2-induced alkaline phosphatase (ALP) activity in C2C12 cells. Laser irradiation at 0.5 W for 20 min enhanced BMP2-induced ALP activity. Laser treatment alone did not affect ALP activity. To exclude the effect of pH or temperature changes during irradiation, we shortened the exposure time to 2 min, with various levels of laser power. At 2.5 W, irradiation stimulated BMP2-induced ALP activity but not cell proliferation, whereas 1 or 5 W laser power did not induce any significant effects. Irradiation stimulated BMP2-induced phosphorylation of Smad1/5/8 and BMP2 expression, but had no effect on the expression of inhibitory Smads 6 and 7, BMP4, or insulin-like growth factor 1. Laser irradiation enhanced Smad-induced Id1 reporter activity as well as expression of bone morphogenetic protein (BMP)-induced transcription factors such as Id1, Osterix, and Runx2. Laser irradiation also stimulated BMP-induced expressions of type I collagen, osteonectin, and osteocalcin mRNA, markers of osteoblasts. This enhancement of BMP2-induced ALP activity and Smad phosphorylation by laser irradiation was also observed in primary osteoblasts. These results suggest that LLLI accelerates the differentiation of BMP-induced osteoblasts by stimulating the BMP/Smad signaling pathway.",
author = "Shizu Hirata and Chiaki Kitamura and Hidefumi Fukushima and Ikuo Nakamichi and Yoshimitsu Abiko and Masamichi Terashita and Eijiro Jimi",
year = "2010",
month = "12",
day = "15",
doi = "10.1002/jcb.22872",
language = "English",
volume = "111",
pages = "1445--1452",
journal = "Journal of Cellular Biochemistry",
issn = "0730-2312",
publisher = "Wiley-Liss Inc.",
number = "6",

}

TY - JOUR

T1 - Low-level laser irradiation enhances BMP-induced osteoblast differentiation by stimulating the BMP/Smad signaling pathway

AU - Hirata, Shizu

AU - Kitamura, Chiaki

AU - Fukushima, Hidefumi

AU - Nakamichi, Ikuo

AU - Abiko, Yoshimitsu

AU - Terashita, Masamichi

AU - Jimi, Eijiro

PY - 2010/12/15

Y1 - 2010/12/15

N2 - Low-level laser irradiation (LLLI) has been shown to induce bone formation and osteoblast differentiation both in vivo and in vitro. However, the molecular mechanism by which LLLI stimulates osteoblast differentiation is still unclear. The aim of the present study was to examine whether Ga-Al-As laser irradiation could enhance BMP2-induced alkaline phosphatase (ALP) activity in C2C12 cells. Laser irradiation at 0.5 W for 20 min enhanced BMP2-induced ALP activity. Laser treatment alone did not affect ALP activity. To exclude the effect of pH or temperature changes during irradiation, we shortened the exposure time to 2 min, with various levels of laser power. At 2.5 W, irradiation stimulated BMP2-induced ALP activity but not cell proliferation, whereas 1 or 5 W laser power did not induce any significant effects. Irradiation stimulated BMP2-induced phosphorylation of Smad1/5/8 and BMP2 expression, but had no effect on the expression of inhibitory Smads 6 and 7, BMP4, or insulin-like growth factor 1. Laser irradiation enhanced Smad-induced Id1 reporter activity as well as expression of bone morphogenetic protein (BMP)-induced transcription factors such as Id1, Osterix, and Runx2. Laser irradiation also stimulated BMP-induced expressions of type I collagen, osteonectin, and osteocalcin mRNA, markers of osteoblasts. This enhancement of BMP2-induced ALP activity and Smad phosphorylation by laser irradiation was also observed in primary osteoblasts. These results suggest that LLLI accelerates the differentiation of BMP-induced osteoblasts by stimulating the BMP/Smad signaling pathway.

AB - Low-level laser irradiation (LLLI) has been shown to induce bone formation and osteoblast differentiation both in vivo and in vitro. However, the molecular mechanism by which LLLI stimulates osteoblast differentiation is still unclear. The aim of the present study was to examine whether Ga-Al-As laser irradiation could enhance BMP2-induced alkaline phosphatase (ALP) activity in C2C12 cells. Laser irradiation at 0.5 W for 20 min enhanced BMP2-induced ALP activity. Laser treatment alone did not affect ALP activity. To exclude the effect of pH or temperature changes during irradiation, we shortened the exposure time to 2 min, with various levels of laser power. At 2.5 W, irradiation stimulated BMP2-induced ALP activity but not cell proliferation, whereas 1 or 5 W laser power did not induce any significant effects. Irradiation stimulated BMP2-induced phosphorylation of Smad1/5/8 and BMP2 expression, but had no effect on the expression of inhibitory Smads 6 and 7, BMP4, or insulin-like growth factor 1. Laser irradiation enhanced Smad-induced Id1 reporter activity as well as expression of bone morphogenetic protein (BMP)-induced transcription factors such as Id1, Osterix, and Runx2. Laser irradiation also stimulated BMP-induced expressions of type I collagen, osteonectin, and osteocalcin mRNA, markers of osteoblasts. This enhancement of BMP2-induced ALP activity and Smad phosphorylation by laser irradiation was also observed in primary osteoblasts. These results suggest that LLLI accelerates the differentiation of BMP-induced osteoblasts by stimulating the BMP/Smad signaling pathway.

UR - http://www.scopus.com/inward/record.url?scp=78649761287&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78649761287&partnerID=8YFLogxK

U2 - 10.1002/jcb.22872

DO - 10.1002/jcb.22872

M3 - Article

C2 - 20830741

AN - SCOPUS:78649761287

VL - 111

SP - 1445

EP - 1452

JO - Journal of Cellular Biochemistry

JF - Journal of Cellular Biochemistry

SN - 0730-2312

IS - 6

ER -