The Effects of Photobiomodulation on MC3T3-E1 Cells via 630 nm and 810 nm Light-Emitting Diode.

BACKGROUND Photobiomodulation (PBM) has been explored as a promising therapeutic strategy to regulate bone cell growth; however, the effects of PBM on osteoblast cell lines remains poorly understood. In addition, as a light source of PBM, the light uniformity of light-emitting diode (LED) devices has not been given enough attention. MATERIAL AND METHODS Here, we sought to investigate the effects of PBM on MC3T3-E1 cells via 630 nm and 810 nm light from a newly designed LED with high uniformity of light. Cell proliferation, flow cytometric analysis, alkaline phosphatase (ALP) staining, ALP activity, Alizarin Red S staining, and quantitative real-time polymerase chain reaction (qRT-PCR) were carried out to assess treatment response. MC3T3-E1 cells were irradiated with LED devices (630±5 nm and 810±10 nm, continuous wave) for 200 seconds at a power density of 5 mW/cm² once daily. RESULTS Increases in cell proliferation and decreases in cell apoptosis were evident following irradiation. ALP staining intensity and activity were also significantly increased following irradiation. Level of mineralization was obviously enhanced in irradiated groups compared with non-irradiated controls. qRT-PCR also showed significant increases in mRNA expression of osteocalcin (OCN) and osteoprotegerin (OPG) in the irradiated groups. CONCLUSIONS Our results showed that LED PBM could promote the proliferation, ALP staining intensity and activity, level of mineralization, gene expression of OCN and OPG of MC3T3-E1 cells, with no significant difference between the 630 nm- and 810 nm-irradiated groups.

MicroRNAs' Involvement in Osteoarthritis and the Prospects for Treatments.

Osteoarthritis (OA) is a chronic disease and its etiology is complex. With increasing OA incidence, more and more people are facing heavy financial and social burdens from the disease. Genetics-related aspects of OA pathogenesis are not well understood. Recent reports have examined the molecular mechanisms and genes related to OA. It has been realized that genetic changes in articular cartilage and bone may contribute to OA's development. Osteoclasts, osteoblasts, osteocytes, and chondrocytes in joints must express appropriate genes to achieve tissue homeostasis, and errors in this can cause OA. MicroRNAs (miRNAs) are small noncoding RNAs that have been discovered to be overarching regulators of gene expression. Their ability to repress many target genes and their target-binding specificity indicate a complex network of interactions, which is still being defined. Many studies have focused on the role of miRNAs in bone and cartilage and have identified numbers of miRNAs that play important roles in regulating bone and cartilage homeostasis. Those miRNAs may also be involved in the pathology of OA, which is the focus of this review. Future studies on the role of miRNAs in OA will provide important clues leading to a better understanding of the mechanism(s) of OA and, more particularly, to the development of therapeutic targets for OA.

Effect of cervus and cucumis peptides on osteoblast activity and fracture healing in osteoporotic bone.

Osteoporosis is associated with delayed and/or reduced fracture healing. As cervus and cucumis are the traditional Chinese treatments for rheumatoid arthritis, we investigated the effect of supplementation of these peptides (CCP) on bone fracture healing in ovariectomized (OVX) osteoporotic rats in vitro and in vivo. CCP enhanced osteoblast proliferation and increased alkaline phosphatase activity, matrix mineralization, and expression of runt-related transcription factor 2 (Runx2), bone morphogenetic protein 4 (BMP4), and osteopontin. In vivo, female Sprague-Dawley rats underwent ovariectomy and the right femora were fractured and fixed by intramedullary nailing 3 months later. Rats received intraperitoneal injections of either CCP (1.67 mg/kg) or physiological saline every day for 30 days. Fracture healing and callus formation were evaluated by radiography, micro-CT, biomechanical testing, and histology. At 12 weeks after fracture, calluses in CCP-treated bones showed significantly higher torsional strength and greater stiffness than control-treated bones. Bones in CCP-treated rats reunified and were thoroughly remodeled, while two saline-treated rats showed no bone union and incomplete remodeling. Taken together, these results indicate that use of CCP after fracture in osteoporotic rats accelerates mineralization and osteogenesis and improves fracture healing.