Ling G, Chadwick C A, Berne B, Potten C S, Pontén J, Pontén F
Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala, Sweden.
Acta Derm Venereol. 2001 May;81(2):81-6. doi: 10.1080/00015550152384173.
A cellular p53 response, DNA repair enzymes and melanin pigmentation are important strategies utilized by skin keratinocytes against impairment caused by ultraviolet radiation (UVR). In this study a double-immunofluorescence technique was used to investigate UVR-induced thymine dimers and p53 protein simultaneously. Four healthy volunteers were irradiated on both sides of their buttock skin with a single dose of solar-simulating UVR. One side was pretreated with a topical sunscreen. Biopsies from different time-points were immunostained for visualization of thymine dimers, p53 and proliferation. One single physiological dose of UVR generated widespread formation of thymine dimers throughout the epidermis 4h after irradiation. The level of thymine dimers decreased over time and was followed by a p53 response in the same cells. A late proliferative response was also found. The formation of thymine dimers, the p53 response and the late proliferative response were partially blocked by topical sunscreen. Large inter-individual differences in the kinetics of thymine dimer formation and repair as well as in the p53 response were evident in both sunscreen-protected and unprotected skin.
细胞的p53反应、DNA修复酶和黑色素沉着是皮肤角质形成细胞抵御紫外线辐射（UVR）所致损伤的重要策略。在本研究中，采用双免疫荧光技术同时检测UVR诱导的胸腺嘧啶二聚体和p53蛋白。对4名健康志愿者的臀部皮肤两侧给予单剂量模拟阳光的UVR照射。一侧预先外用防晒霜。在不同时间点取活检组织进行免疫染色，以观察胸腺嘧啶二聚体、p53和增殖情况。单次生理剂量的UVR照射后4小时，整个表皮广泛形成胸腺嘧啶二聚体。胸腺嘧啶二聚体水平随时间下降，随后同一细胞出现p53反应。还发现了晚期增殖反应。外用防晒霜可部分阻断胸腺嘧啶二聚体的形成、p53反应和晚期增殖反应。在使用防晒霜保护和未保护的皮肤中，胸腺嘧啶二聚体形成和修复的动力学以及p53反应均存在明显的个体间差异。
