Wirkung von Blaulicht auf humane Hautzellen

During wound healing skin fibroblasts play a pivotal role in synthesis and remodelling of the dermal extracellular matrix. An impaired physiological elimination of activated fibroblasts or myo-fibroblasts from scar tissue via apoptosis correlates with the development of hypertrophic scars and keloids. In the present study we examined a new fibroblast-specific light-based mechanism of apoptosis induction. Incubation of human skin fibroblasts with Interferon-gamma (IFN-γ) at physiological concentrations did not exhibit any toxic effects. Exposure of human skin fibroblasts to intensive blue light (420 nm and up to 80 J/cm2) had no significant effects on fibroblasts viability as detected by Neutral-Red-staining. Interestingly, blue light-challenge of IFN-γ-preincubated cell fibroblast cultures significantly induced apoptosis as revealed by condensed chromatin and fragmented nuclei. Interestingly, analogue experiments with IFN-γ-preincubated and irradiated keratinocyte cultures did not show any significant effects on viability. Therefore, we postulate that IFN-γ and blue light represent an effective fibroblast-specific apoptosis-inducing mechanism when both stimuli are used synergistically. Both stimuli are used in dermatological harmless range; thus, the described mechanism provides a powerful tool for therapy or prophylaxis of scar and keloid formation.