The effects of low-level Er:YAG laser irradiation on proliferation and calcification of primary osteoblast-like cells isolated from rat calvaria

ABSTRACT: A number of reports showed that photo-bio-modulation by various lasers has favorable biological effects on cells. However, the effects of low-level Er:YAG laser irradiation on osteoblasts remain unclear. The purpose of this study was to evaluate the effects on proliferation and osteogenic differentiation of primary osteoblast-like cells by low-level Er:YAG laser irradiation. Osteoblast-like cells isolated from the calvariae of 3–5-day-old Wistar rats were irradiated by Er:YAG laser at energy fluences of 2.2, 3.3, or 4.3 J/cm2, respectively. After irradiation, cell surface temperature was measured and cell proliferation was evaluated by flow cytometry. Calcification was evaluated by measuring the Alizarin red S staining area after 7-day-culture with osteoinductive medium. Gene expressions in non-irradiated and laser-irradiated cells were evaluated by qPCR at 3, 6, and 12 hours after irradiation. Microarray analysis was performed to comprehensively evaluate gene expressions of non-irradiated cells and irradiated cells at 3.3 J/cm2 at 6 hours after irradiation. No pronounced increase of cell surface temperature was induced by low-level Er:YAG laser irradiation, and the Er:YAG laser irradiation did not affect osteoblast-like cell proliferation. Osteoblast-like cell calcification was significantly increased 7 days after Er:YAG laser irradiation at 3.3 J/cm2. Bglap expression was significantly increased in cells irradiated at 3.3 J/cm2 at 6 hours post-irradiation. Microarray analysis showed that irradiation at 3.3 J/cm2 caused up-regulation of inflammation-related genes and down-regulation of Wisp2. Gene set enrichment analysis also clarified enrichment of inflammation-related gene sets and Notch signaling pathway. In conclusion, Low-level Er:YAG laser irradiation enhanced calcification of primary osteoblast-like cells via enhanced Bglap expression and enriched Notch signaling pathway.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE146098 | GEO | 2022/02/28

REPOSITORIES: GEO