Journal of the Japanese Association of Regenerative Dentistry
J Jpn Assoc Regenerative Dent Vol.8(1) pp.1-9
ISSN 1348-9615


Low-energy laser irradiation stimulates the differentiation of human mesenchymal stem cells into osteoblasts via the expression of Cbfa1 and Osx

Masaru YAMAGUCHI1, Machi TAKANO1, Chikako SOMEI2, Yasuhiro TANIMOTO3, Moriyasu WADA2, Kazutaka KASAI1
Department of 1Orthodontics, 2Renascent dentistry, 3Dental biomaterials,
Nihon University School of Dentistry at Matsudo, Chiba, Japan

The aim of this study was to investigate the effects of low-energy laser irradiation on differentiation to osteoblasts of human mesenchymal stem cells (hMSC). Alkaline phosphatase (ALP) activity and osteocalcin release were measured from irradiated-hMSC. The expressions of core binding factor a1 (Cbfa1) and osterix (Osx) were also examined by RT-PCR.
Low-energy laser irradiation (Ga-Al-As semi-conductor laser, output 50 mW) was applied to hMSC for 3 min (9.33 J/cm2/min: 27.99J/cm2), at 24 h intervals during the culture period of 28 days.
The laser irradiation groups showed significantly greater both ALP activity during experimental period and osteocalcin release on days 14 to 28 in comparison with the control group. RT-PCR results also showed that the expressions of Cbfa1 and Osx were up-regulated on days 3 and 7. The present results suggest that low-energy laser irradiation facilitates differentiation to osteoblasts of hMSC via Cbfa1 and Osx expressions.

Keyword: low-energy laser irradiation, human mesenchymal stem cells, osteoblast