Two distinct pathways leading to nuclear apoptosis.
Apaf-1(-/-) or caspase-3(-/-) cells treated with a variety of apoptosis inducers manifest apoptosis-associated alterations including the translocation of apoptosis-inducing factor (AIF) from mitochondria to nuclei, large scale DNA fragmentation, and initial chromatin condensation (stage I). However, when compared with normal control cells, Apaf-1(-/-) or caspase-3(-/-) cells fail to exhibit oligonucleosomal chromatin digestion and a more advanced pattern of chromatin condensation (stage II). Microinjection of such cells with recombinant AIF only causes peripheral chromatin condensation (stage I), whereas microinjection with activated caspase-3 or its downstream target caspase-activated DNAse (CAD) causes a more pronounced type of chromatin condensation (stage II). Similarly, when added to purified HeLa nuclei, AIF causes stage I chromatin condensation and large-scale DNA fragmentation, whereas CAD induces stage II chromatin condensation and oligonucleosomal DNA degradation. Furthermore, in a cell-free system, concomitant neutralization of AIF and CAD is required to suppress the nuclear DNA loss caused by cytoplasmic extracts from apoptotic wild-type cells. In contrast, AIF depletion alone suffices to suppress the nuclear DNA loss contained in extracts from apoptotic Apaf-1(-/-) or caspase-3(-/-) cells. As a result, at least two redundant parallel pathways may lead to chromatin processing during apoptosis. One of these pathways involves Apaf-1 and caspases, as well as CAD, and leads to oligonucleosomal DNA fragmentation and advanced chromatin condensation. The other pathway, which is caspase-independent, involves AIF and leads to large-scale DNA fragmentation and peripheral chromatin condensation.
Susin
S A
SA
Centre National de la Recherche Scientifique, UMR1599, Institut Gustave Roussy, F-94805 Villejuif, France.
Daugas
E
E
Ravagnan
L
L
Samejima
K
K
Zamzami
N
N
Loeffler
M
M
Costantini
P
P
Ferri
K F
KF
Irinopoulou
T
T
Prévost
M C
MC
Brothers
G
G
Mak
T W
TW
Penninger
J
J
Earnshaw
W C
WC
Kroemer
G
G
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology*; D051033:Apoptosis Inducing Factor; D053477:Apoptotic Protease-Activating Factor 1; D018053:Arsenites / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology; D003574:Cytochrome c Group / Q000235:genetics / Q000378:metabolism; D053938:DNA Fragmentation; D003851:Deoxyribonucleases / Q000235:genetics / Q000378:metabolism; D005047:Etoposide / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008845:Microinjections; D008928:Mitochondria / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
C494829:AIFM1 protein, human; C506592:APAF1 protein, human; D000970:Antineoplastic Agents; C506593:Apaf1 protein, mouse; D051033:Apoptosis Inducing Factor; D053477:Apoptotic Protease-Activating Factor 1; D018053:Arsenites; D003574:Cytochrome c Group; D005420:Flavoproteins; D005456:Fluorescent Dyes; D008565:Membrane Proteins; C494830:AIFM1 protein, mouse; D011506:Proteins; D011994:Recombinant Proteins; D005047:Etoposide; D003851:Deoxyribonucleases; C109663:caspase-activated deoxyribonuclease; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; C015001:arsenite; D002945:Cisplatin