BLUE LED LIGHT AFFECTS CYTOCHROME C AND IONIC MEMBRANE CURRENTS IN HUMAN CULTURED KELOID FIBROBLASTS

Aim: the effects of the blue LED light were investigated in human fibroblasts isolated from keloid tissues. We focused our attention on the blue LED light modulation of cell metabolism, proliferation rate and membrane current amplitude. We also investigated the possible involvement in the blue LED light effects of adenosine A2A receptors, which play a crucial role in collagen deposition and wound healing process. Methods: we used a blue LED light emitting in the visible range (410 - 430 nm), on cultured keloid fibroblasts. Five different fluence doses, between 3 and 41 J/cm2 were applied. Cell metabolism, proliferation and cell viability were evaluated by specific biochemical assays, while ionic membrane currents were recorded by patch clamp experiments. Finally, the Cytochrome C redox state was assessed by Raman Spectroscopy. ZM241385, a selective adenosine A2A receptor antagonist, was applied in culture medium 24 hours before irradiation and its effect was estimated measuring cell proliferation. Results / Discussion: the blue LED light decreases both cell metabolism and proliferation of keloid fibroblasts, in a dose-dependent manner. When using a dose of 21.6 J/cm2, it directly affects Cytochrome C, which switches from the oxidized to the reduced form. At the same dose, blue LED light increases outward potassium currents, demonstrating that it might modulates cell cycle. ZM241385 reduces, di per se, fibroblasts proliferation and partly occludes the effects of light exposure on this cells parameter. Conclusion: the blue LED light treatment could be an innovative and non-pharmacological approach in the management of skin fibrosis.