Port-Lougarre Yannick, Voegeli Guillaume, Vileno Bertrand, Giménez-Arnau Elena
Institut de Chimie, UMR 7177, CNRS, Université de Strasbourg, Strasbourg, France.
Photochem Photobiol. 2025 Mar-Apr;101(2):275-281. doi: 10.1111/php.14010. Epub 2024 Aug 27.
Photoallergic contact dermatitis is a skin disease caused by combined exposure to photoreactive chemicals and sunlight. Exposure to allergens and the risk of skin sensitization is an essential regulatory issue within the industry. Yet, only few non-validated assays for photoallergy assessment exist as the pathogenesis is not fully deciphered. Improving such assays and/or developing new ones require an understanding of the chemical mechanisms involved. The first key event in the photosensitization process, namely chemical binding of the photoallergen to endogenous proteins, is thought to proceed via photo-mediated radicals arising from the photoallergen. Moreover, the mechanism of action of these radicals if formed in the epidermis is not known and far from being unraveled. We present here an original proof-of-concept methodology to probe radical generation from allergens in contact with photoexposed skin, using electron paramagnetic resonance and spin trapping in a reconstructed human epidermis model mimicking real-life exposure scenarios.
光变应性接触性皮炎是一种因同时接触光反应性化学物质和阳光而引起的皮肤病。接触过敏原以及皮肤致敏风险是该行业内一个至关重要的监管问题。然而，由于发病机制尚未完全阐明，目前仅有少数未经验证的光过敏评估检测方法。改进此类检测方法和/或开发新的检测方法需要了解其中涉及的化学机制。光致敏过程中的第一个关键事件，即光变应原与内源性蛋白质的化学结合，被认为是通过光变应原产生的光介导自由基进行的。此外，这些自由基在表皮中形成后的作用机制尚不清楚，远未被揭示。在此，我们提出一种原创的概念验证方法，利用电子顺磁共振和自旋捕获技术，在模拟实际暴露场景的重建人表皮模型中，探测与光暴露皮肤接触的过敏原产生自由基的情况。
