Low‐energy red light‐emitting diode irradiation enhances osteogenic differentiation of periodontal ligament stem cells by regulating miR‐146a‐5p

Abstract Aims The study aimed to investigate the role of miR‐146a‐5p in osteogenesis of hPDLSCs irradiated with low‐energy red LEDs. Methods After irradiation with 5 J/cm 2 red LED, miR‐146a‐5p expression was detected by real‐time quantitative polymerase chain reaction (RT‐qPCR), and osteogenic markers expression was determined by RT‐qPCR and Western blotting. Alkaline phosphatase (ALP) activity was assessed by ALP staining, and mineralization was assessed by Alizarin Red staining, respectively. Lentiviral vectors were designed to regulate miR‐146a‐5p expression. Dual‐luciferase reporter assay was performed to confirm the targeted relationship between miR‐146a‐5p and MAPK1. Short hairpin RNA (shRNA) was used to regulate MAPK1 expression. Results RT‐qPCR and western blotting revealed that 5 J/cm 2 irradiation elevated the levels of the osteogenic markers osterix (OSX) and bone sialoprotein (BSP) in hPDLSCs. miR‐146a‐5p is downregulated in hPDLSCs under the low‐energy red LED light irradiation. miR‐146a‐5p underexpression markedly promoted the osteogenic potential of hPDLSCs. miR‐146a‐5p targeted MAPK1. 5 J/cm 2 red LED irradiation rescued the inhibitory effects of upregulated miR‐146a‐5p on osteogenic differentiation, and the positive influence of red LED irradiation could be reversed by downregulated MAPK1. Conclusion These findings confirm that miR‐146a‐5p is involved in the effect of LED irradiation on the osteogenic differentiation of hPDLSCs by targeting MAPK1. Red LED irradiation may be a potential clinical adjunct therapy for periodontal regeneration.