Low-intensity photobiomodulation at 632.8 nm increases tgfβ3, col2a1, and sox9 gene expression in rat bone marrow mesenchymal stem cells in vitro

Abstract

The high incidence of cartilage destructions, as well as the social and economic importance of this pathology attracted great interest to the problem. At the present time, some data are available about the 632.8 nm low-intensity laser photobiomodulation positive effect on the cartilage tissue proliferation. The effect of this wavelength laser irradiation on the mesenchimal stem cell (MSC) differentiation in the chondrogenic direction was studied. The main aim of this work was to assess the low-intensity photobiomodulation effect on chondrogenesis. In this experiment, the cell model was used to compare the photobiomodulation and cytokine Tgfβ3 (transforming growth factor β 3) effects. Bone marrow MSCs were isolated from Wistar rats and cultured for the third passage. Chondrogenic effects of low-intensity He-Ne laser photobiomodulation and cytokine Tgfβ3 (10 ng/μL) were analyzed and compared after 21 days. The radiation source was the standard LGN-208 helium-neon (He-Ne) laser (632.8 nm, 1.7 mWt). Irradiation was performed cyclically for 15 min with 45-min pauses. The increase of the responsible for chondrogenesis (col2a1, tgfβ3, and sox9) main gene expression under the photobiomodulation at 632.8 nm was evaluated in comparison with Tgfβ3 effect. The tgfβ3, col2a1, and sox9 gene expression increase was obtained in two experimental groups: using the laser photobiomodulation and cytokine Tgfβ3 effect. Gene expression levels of tgfβ3, col2a1, and sox9 were measured using real-time polymerase chain reaction (RT-PCR) according to the -ΔΔCt method. It was found that the responsible for chondrogenesis genes expression (tgfβ3, col2a1, sox9) increased under the action of specific laser photobiomodulation during the observation period (from 0 to 21 days). The chondrogenic differentiation effect under the laser irradiation is less significant than Tgfβ3 cytokine effect.

Keywords: Chondrogenesis; Low-intensity laser radiation; col2a1; sox9 gene expression; tgfβ3.