Photobiomodulation at 660nm promotes collagen synthesis via downregulation of HIF-1α expression without photodamage in human scleral fibroblasts in vitro in a hypoxic environment.

Abstract

The increasing prevalence of myopia is a global public health issue. Because of the complexity of myopia pathogenesis, current control methods for myopia have great limitations. The aim of this study was to explore the effect of photobiomodulation (PBM) on human sclera fibroblasts (HSFs) under hypoxia, in the hope of providing new ideas for myopia prevention and control. Hypoxic cell model was established at 0, 6, 12, and 24h time points to simulate myopia microenvironment and explore the optimal time point. Control, hypoxia, hypoxia plus light, and normal plus light cell models were set up for the experiments, and cells were incubated for 24 or 48h after PBM (660nm, 5J/cm2), followed by evaluation of hypoxia-inducible factor 1α (HIF-1α) and collagen I a1 (COL1A1) proteins using Western blotting and immunofluorescence, and photo damage was detected by CCK-8, scratch test, and flow cytometry assays. We also used transfection technology to further elucidate the regulatory mechanism. The change of target proteins is most obvious when hypoxia lasts for 24h (p < 0.01). PBM at 660nm increased extracellular collagen content (p < 0.001) and downregulated expression of HIF-1α (p < 0.05). This treatment did not affect the migration and proliferation of cells (p > 0.05), and effectively inhibited apoptosis under hypoxia (p < 0.0001). After overexpression of HIF-1α, the effect of PBM was attenuated (p > 0.05). Photobiomodulation at 660nm promotes collagen synthesis via downregulation of HIF-1α expression without photodamage.