In vitro effects of photobiomodulation on cell migration and gene expression of ALP, COL-1, RUNX-2, and osterix in cementoblasts

The aim of this study was to evaluate the effects of photobiomodulation (PBM) on cell migration and alkaline phosphatase (ALP), type I collagen (Col-1), runt-related transcription factor 2 (RUNX-2), and Osterix (OSX) gene expression in a cementoblast culture (OCCM-30), in a microenvironment mimicking an injury on the cementoblast layer, such as it occurs during root resorption. For this, OCCM-30 cells were cultured in 6-well plates and the following parameters were assayed: (1) migration by scratch assay and ALP, Col-1, Runx2, and Osx by real-time PCR. PBM was performed in two protocols using a LED device emitting light at 660 nm (± 30 nm). OCCM-30 cementoblasts were grown and divided into four groups: (1) negative control; (2) positive control (scratch); (3) scratch + PBM with a total energy of 36 J and energy density 1.6 J/cm 2 ; and (4) scratch + PBM with a total energy of 72 J and energy density of 3.2 J/cm 2 . Data were statistically analyzed, with the level of significance set at 5%. Cementoblasts migrated from the edge of the scratch toward the center, and the wound closed after 24 h, with the PBM3.2J/cm 2 group showing the higher cell migration compared with the other groups at 2 h, 6 h, 8 h, and 13 h ( p < 0.05). The control and PBM1.6J/cm 2 groups showed similar levels of cell migration, with no significant differences ( p > 0.05). PBM3.2J/cm 2 group exhibited greater ALP, Col-1, OSX, and RUNX2 in comparison with the other experimental groups ( p < 0.05). Similar levels of all genes evaluated were observed between the PBM1.6J/cm 2 group and the positive control group ( p > 0.05). In conclusion, our findings support the effectiveness of photobiomodulation on cementoblast migration and gene expression, which may contribute to the formation of a new cementum layer.