Phosphatidylserine induces apoptosis in CHO cells without mitochondrial dysfunction in a manner dependent on caspases other than caspases-1, -3, -8 and -9.
Treatment of Chinese hamster ovary K1 cells with phosphatidylserine (PS) caused typical apoptosis with distinct morphological and biochemical features in a dose- and time-dependent manner. However, unlike camptothecin-induced apoptosis, changes in mitochondrial transmembrane potential were not observed. In addition, cytochrome c release did not occur in PS-induced apoptosis. A pan caspase inhibitor, Z-VAD, significantly inhibited the apoptosis, but inhibitors of caspase-1, -3, -8 and -9 did not. Activities of caspase-1, -3, -8 and -9 were increased by treatment of the cells with camptothecin, but not with PS. These results suggest that PS-induced apoptosis occurs without the collapse of mitochondrial transmembrane potential and without the release of cytochrome c, in a manner independent of caspase-1, -3, -8 and -9.
Miyato
Y
Y
Laboratory of Radiation Biology, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Japan.
Ibuki
Y
Y
Ohyama
H
H
Yamada
T
T
Goto
R
R
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D016466:CHO Cells; D020169:Caspases / Q000378:metabolism*; D006224:Cricetinae; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D008928:Mitochondria / Q000502:physiology*; D010641:Phenotype; D010718:Phosphatidylserines / Q000502:physiology*
D015853:Cysteine Proteinase Inhibitors; D003574:Cytochrome c Group; D010718:Phosphatidylserines; D020169:Caspases