Medaka (Oryzias latipes) Embryo as a Model for the Screening of Compounds That Counteract the Damage Induced by Ultraviolet and High-Energy Visible Light.

Marián Merino,Ana Sánchez-Sánchez,José Mullor

doi:10.3390/ijms21165769

Abstract

Continuous overexposure to sunlight increases its harmful effects on the skin. For this reason, there is a growing need to characterize economic models more representative of the negative effects and counteracting responses that irradiation causes on human skin. These models will serve for the screening of protective compounds against damage caused by ultraviolet (UV) and high energy visible light (HEV). Therefore, two common in vitro models employed for sunlight irradiation studies, namely human keratinocyte HaCat culture and reconstructed human epidermis (RHE), were compared with the medaka fish embryo model, traditionally used in other scientific disciplines. Using suberythemal doses of UVA and HEV to determine the level of Reactive Oxygen Species (ROS) generation and thymine dimers formed by UVB, we show that medaka embryo responds with a lower damage level, more comparable to human skin, than the other two models, probably due to the protective mechanisms that work in a complete organism. In the same way, the protective effects of antioxidant compounds have the greatest effect on medaka embryos. Taken together, these findings suggest that medaka embryos would be a good alternative in vitro model for sunlight effect studies, and for the screening of molecules with counteracting capacity against the damage caused by UV and HEV.

Highlights

Ultraviolet (UV) radiation from the sun is a natural source of energy with proven benefits for humans, such as the production of Vitamin D in the skin triggered by UVB light (290–320 nm), which is important for normal bone formation
To determine the effect of UVB irradiation on generating DNA damage by measuring the thymine dimers accumulation, HaCat cells, reconstructed human epidermis (RHE), and fish embryos were exposed to a total dose of 0.04 J/cm2
Results indicated that UVB irradiation significantly induced DNA lesions in the form of thymine dimers compared to non-irradiated controls

Summary

Introduction

Ultraviolet (UV) radiation from the sun is a natural source of energy with proven benefits for humans, such as the production of Vitamin D in the skin triggered by UVB light (290–320 nm), which is important for normal bone formation. UV radiation can be very harmful causing serious skin problems, such as skin burns, oxidative stress imbalance, inflammation, immune alterations, or DNA damage [2]. One of the main contributors to skin photoaging is the formation of ROS that induce oxidative stress. UV radiation contains less of the 10% of solar radiation, whereas visible light (400–700 nm) comprises around 43%, and has been reported as an important ROS producer in the skin, contributing to signs of premature photoaging due to the oxidative stress imbalance [5]. New man-made sources of visible light are widely present in our lives due to technological evolution, such as screens of electronic devices or LED lighting, that contribute to skin damage [6]

Methods

Results

Conclusion