Photobiological and thermal effects of photoactivating UVA light doses on cell cultures
Photobiological and thermal effects of photoactivating UVA light doses on cell cultures
复制标题
DOI：
10.1039/b616979a
复制
发表时间：
2007-06-01
影响因子：
3.1
通讯作者：
Monroe, W. Todd
中科院分区：
文献类型：
--
作者：
Forman, Julianne;Dietrich, Marilyn;Monroe, W. Todd
虽然近紫外光已被广泛用于光激活细胞中的荧光团和笼状化合物，但人们对这种光的长期生物效应知之甚少。 UVA (315-400 nm) 光活化光已在短期细胞研究中得到充分表征，目前正以更高剂量用于控制较长持续时间的现象（例如基因表达）。使用膜联蛋白V-Cy5/碘化丙啶凋亡流式细胞术测定HeLa细胞对高达23.85 J cm(-2)的UVA光剂量的反应。与以较高密度接种的细胞相比，以低密度接种的细胞具有更高的凋亡和坏死百分比，并且也更容易受到 UVA 损伤。确定了两种不同的市售UVA光源诱导50%细胞凋亡和死亡的剂量（剂量（1/2））：GreenSpot光固化系统为7.6 J cm(-2)，BlakRay灯为2.52 J cm(-2)。所有测试的 BlakRay 剂量均具有显着的细胞反应，而来自 GreenSpot 光源的剂量低于 1.6 J cm(-2) 则未发现显着的细胞反应。使用温度控制和测量系统来确定 UVA 源的直接加热，以及曝光期间冷却细胞培养物对最大限度减少细胞损伤的影响。 BlakRay 曝光期间的冷却显着降低了坏死细胞的百分比，但 GreenSpot 光激活期间的冷却没有显着差异。细胞对不同强度的相似 UVA 剂量的反应差异表明，在光活化研究中，应将光持续时间与总剂量和热条件一起考虑。
While near-ultraviolet light has been widely used to photoactivate fluorophores and caged compounds in cells, little is known of the long-term biological effects of this light. UVA (315-400 nm) photoactivating light has been well characterized in short-term cell studies and is now being employed in higher doses to control longer-duration phenomena (e.g. gene expression). Annexin V-Cy5/propidium iodide apoptosis flow cytometry assays were used to determine responses of HeLa cells to doses of UVA light up to 23.85 J cm(-2). Cells seeded at low densities had higher percentages of apoptosis and necrosis and were also more susceptible to UVA damage than cells seeded at higher densities. The dose to induce apoptosis and death in 50% of the cells (dose(1/2)) was determined for two different commercially available UVA light sources: 7.6 J cm(-2) for the GreenSpot photocuring system and 2.52 J cm(-2) for the BlakRay lamp. All BlakRay doses tested had significant cellular responses, whereas no significant cellular responses were found for doses below 1.6 J cm(-2) from the GreenSpot light source. A temperature control and measurement system was used to determine direct heating from the UVA sources and also the effect that cooling cell cultures during photoexposure has on minimizing cell damage. Cooling during the BlakRay photoexposure significantly reduced the percentage of necrotic cells, but there was no significant difference for cooling during photoactivation with the GreenSpot. Differences in cell responses to similar UVA doses of different intensities suggest that photoduration should be considered along with total dose and thermal conditions in photoactivation studies.