Irradiation with blue light-emitting diode enhances osteogenic differentiation of stem cells from the apical papilla

• DOI: 10.1007/s10103-020-02995-3
• Publication Date: 2020-03-16T03:02:31Z
• Authors: Yaoyao Yang; Tingting Zhu; Yan Wu; Chunxia Shu; Qiang Chen; Juan Yang; Xiang Luo; Yao Wang
• Keywords: 0301 basic medicine; Extracellular Matrix Proteins; Sialoglycoproteins; Stem Cells; Osteocalcin; Cell Differentiation; Dentinogenesis; Alkaline Phosphatase; Phosphoproteins; 3. Good health; 03 medical and health sciences; Gene Expression Regulation; Osteogenesis; Humans; Calcium; Dental Papilla; Cells, Cultured; Cell Proliferation

This study aimed to evaluate the effects of low-energy blue LED irradiation on the osteogenic differentiation of stem cells from the apical papilla (SCAPs). SCAPs were derived from human tooth root tips and were irradiated with 0 (control group), 1 J/cm2, 2 J/cm2, 3 J/cm2, or 4 J/cm2 blue light in osteogenic induction medium. Cell proliferation was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Osteogenic differentiation activity was evaluated by monitoring alkaline phosphatase (ALP), alizarin red staining, and real-time polymerase chain reaction (RT-PCR). The results of the MTT assay indicated that SCAPs in the LED groups exhibited a lower proliferation rate than those in the control group, and there were statistically differences between the 2 J/cm2, 3 J/cm2, and 4 J/cm2 groups and the control group (P < 0.05). The results of the ALP and alizarin red analyses showed that blue LED promoted osteogenic differentiation of the SCAPs. And 4 J/cm2 blue light upregulates the expression levels of the osteogenic/dentinogenic genes ALP, dentin sialophosphoprotein (DSPP), dentin matrix protein-1 (DMP-1), and osteocalcin (OCN) in SCAPs. Our results confirmed that low-energy blue LED at 1 J/cm2, 2 J/cm2, 3 J/cm2, and 4 J/cm2 could inhibit the proliferation of SCAPs and promotes osteogenic differentiation of SCAPs. Further in vitro studies are required to explore the mechanisms of the effects by low-energy blue LED.