UV-induced apoptasis and photorepair

UVA(340~400 nm)、UVB(290~320 nm)和UVC(200~290 nm)三个波长的紫外线照射可通过DNA梯带形成诱导OCP13细胞凋亡。各波长UV照射后4h内细胞形态发生改变，但仅UVB或UVC照射后细胞形态发生改变，而UVA照射后细胞形态改变不明显。1)，放线菌酮可抑制紫外线诱导的细胞从底物上脱落。2)紫外光照射后，细胞形态发生扭曲、重排等形态变化的特征。3)，上述形态变化可以通过光修复来避免。4)紫外光照射后，贴附在塑料培养皿和盖片上的细胞形态变化相似。5)，在哺乳动物细胞凋亡过程中被激活的caspase3在紫外线照射后也被高度激活，这一结果表明长波紫外线(UVA)和短波紫外线(UVB和UVC)诱导细胞凋亡的途径不同。UVA诱导的细胞凋亡不是通过CPDS触发的，也不像UVB和UVC诱导的那样需要caspase3活性。

UV radiation from three wavelengths, i.e.UVA (340-400 nm), UVB (290-320 nm) and UVC (200-290 nm), were shown to induce apoptosis in OCP13 cells by DNA ladder formation in cells detached from the plastic dish after irradiation. Morphological changes of the irradiated cells occurred in 4 hours after each wavelength UV.However, the following phenomena only occurred with UVB or UVC irradiation, but not with UVA irradiation. 1), UV-induced detachment of cells from substratum was inhibited with cycloheximide treatment. 2), the characteristic features of the morphological changes after UV irradiation, such as distorted nuclear shape and rearrangement of cells occurred. 3), the morphological changes described above could be evaded by photorepair. 4), the cells attached on both plastic dish and coverslip shows similar morphological changes after UV irradiation. 5), caspase 3, which is activated in apoptosis process in mammalian cells, was also highly activated after UV irradiation.These results indicate a different pathway between long (UVA) and short (UVB and UVC) wavelength UV-induced apoptosis. UVA-induced apoptosis would not be triggered through CPDs or requires caspase 3 activity as UVB and UVC-induced apoptosis.