Podda M, Traber M G, Weber C, Yan L J, Packer L
University of California Berkeley, Department of Molecular and Cell Biology, 94720-3200, USA.
Free Radic Biol Med. 1998 Jan 1;24(1):55-65. doi: 10.1016/s0891-5849(97)00142-1.
The degree to which antioxidant loss occurs in human skin after UV irradiation is unknown, as is the cascade of events that might occur. We have, therefore, evaluated a tissue culture model of human skin for its usefulness for studying oxidative injury by UV-irradiation. Human skin equivalents, a tissue culture model, were irradiated using a full solar UV spectrum (UVA and UVB, 280-400 nm) (0 to 16.8 J/cm2, 0-12 minimal erythemal dose, MED), then incubated from 1 to 24 h. Ubiquinol was the most UV-light sensitive antioxidant and was depleted by 2.1 J/cm2 (1.5 MED, p < .004); ubiquinone decreased with 4.2 J/cm2 (3 MED, p < .0007). A linear decrease in alpha-tocopherol occurred--approximately 1.7 pmol tocopherol/cm2 surface were destroyed per J/cm2 UV-light. Urate was depleted by irradiation with 8.4 J/cm2 (6 MED), while ascorbate was depleted by 16.8 J/cm2 (12 MED). Cellular protein carbonyls and lactic dehydrogenase (LDH) leakage into the medium were only increased at 1 h incubation following exposure to 16.8 J/cm2 (12 MED). At 24 h incubation, PGE2 was increased in the medium of cells exposed to UV-irradiation at 0.35 J/cm2 (0.25 MED) compared with sham-exposed cells (p < .04); higher UV exposures lead to significant increases in both PGE2 (p < .001) and LDH (p < .001) in the medium. In conclusion, human skin equivalents respond to suberythemal levels of UV-irradiation by increasing production of PGE2; higher levels of UV-irradiation (at least 1 MED) were needed to deplete cellular antioxidants and induce immediately detectable oxidative damage.
紫外线照射后人体皮肤中抗氧化剂损失的程度尚不清楚，可能发生的一系列事件也不清楚。因此，我们评估了一种人体皮肤组织培养模型，以研究其在紫外线照射引起的氧化损伤研究中的有用性。使用全太阳紫外线光谱（UVA和UVB，280 - 400nm）（0至16.8J/cm²，0 - 12最小红斑剂量，MED）照射人体皮肤等效物（一种组织培养模型），然后孵育1至24小时。泛醇是对紫外线最敏感的抗氧化剂，在2.1J/cm²（1.5MED，p <.004）时被消耗；辅酶Q在4.2J/cm²（3MED，p <.0007）时减少。α-生育酚呈线性下降 - 每J/cm²紫外线大约破坏1.7pmol生育酚/cm²表面。尿酸盐在8.4J/cm²（6MED）照射下被消耗，而抗坏血酸在16.8J/cm²（12MED）时被消耗。细胞蛋白羰基和乳酸脱氢酶（LDH）泄漏到培养基中仅在暴露于16.8J/cm²（12MED）后孵育1小时时增加。在孵育24小时时，与假照射细胞相比，暴露于0.35J/cm²（0.25MED）紫外线照射的细胞培养基中PGE2增加（p <.04）；更高的紫外线暴露导致培养基中PGE2（p <.001）和LDH（p <.001）均显著增加。总之，人体皮肤等效物通过增加PGE2的产生来响应亚红斑水平的紫外线照射；需要更高水平的紫外线照射（至少1MED）来消耗细胞抗氧化剂并立即诱导可检测到的氧化损伤。
