Sustained release of Smac/DIABLO from mitochondria commits to undergo UVB-induced apoptosis.

摘要: Apoptotic response of keratinocytes to UVB irradiation has physiological significance on photocarcinogenesis. Here, we show that the sustained release Smac/DIABLO from mitochondria is an important event for onset apoptosis in exposed irradiation. In human keratinocyte HaCaT cells, at 500 J/m2, but not 150 induces apoptosis. Significant activations caspases-9 and -3, slight activation caspase-7 were observed only J/m2 irradiated cells. Correspondingly, cleavage PARP, a substrate caspases-3 -7, was detected cells UVB, J/m2. However, with both irradiation, cytochrome c, activator caspase-9 via formation apoptosome, released cytosol same extent. contrast, significant amounts are level XIAP decreased. These results suggest extent efflux determinant whether cell will undergo or survival.