Decreased Bone Volume and Bone Mineral Density in the Tibial Trabecular Bone Is Associated with Per2 Gene by 405 nm Laser Stimulation

International Journal of Molecular Sciences

Yeong-Min Yoo¹  Myung-Han Lee²  Ji Hyung Park¹  Dong-Hyun Seo¹  Sangyeob Lee¹  Byungjo Jung¹  Han Sung Kim¹  Kiho Bae² 

[1] Department of Biomedical Engineering, Yonsei-Fraunhofer Medical Device Laboratory, Yonsei University, Wonju, Gangwon-do 26493, Korea;Division of Biological Science and Technology, Yonsei University, Wonju, Gangwon-do 26493, Korea;

关键词: tibia;    trabecular bone;    Per2;    ALP;    Runx;    low-level laser therapy;    minimally invasive laser needle system;   

DOI  :  10.3390/ijms161126028

来源: mdpi

【 摘 要 】

Low-level laser therapy/treatment (LLLT) using a minimally invasive laser needle system (MILNS) might enhance bone formation and suppress bone resorption. In this study, the use of 405 nm LLLT led to decreases in bone volume and bone mineral density (BMD) of tibial trabecular bone in wild-type (WT) and Per2 knockout (KO) mice. Bone volume and bone mineral density of tibial trabecular bone was decreased by 405 nm LLLT in Per2 KO compared to WT mice at two and four weeks. To determine the reduction in tibial bone, mRNA expressions of alkaline phosphatase (ALP) and Per2 were investigated at four weeks after 405 nm laser stimulation using MILNS. ALP gene expression was significantly reduced in the LLLT-stimulated right tibial bone of WT and Per2 KO mice compared to the non-irradiated left tibia (p < 0.001). Per2 mRNA expression in WT mice was significantly reduced in the LLLT-stimulated right tibial bone compared to the non-irradiated left tibia (p < 0.001). To identify the decrease in tibial bone mediated by the Per2 gene, levels of runt-related transcription factor 2 (Runx2) and ALP mRNAs were determined in non-irradiated WT and Per2 KO mice. These results demonstrated significant downregulation of Runx2 and ALP mRNA levels in Per2 KO mice (p < 0.001). Therefore, the reduction in tibial trabecular bone resulting from 405 nm LLLT using MILNS might be associated with Per2 gene expression.

【 授权许可】

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© 2015 by the authors; licensee MDPI, Basel, Switzerland.