Abstract
It was recently reported that the mitochondrial protein cytochrome c is required for the induction of apoptosis, and that the overexpression of Bcl- 2 caused increased retention of this apoptogenic factor by mitochondria. Several cellular toxins, including H2O2, tBOOH and Ca++, induce the Mitochondrial Permeability Transition (MPT); we tested the possibility that MPT is an intracellular sensor of toxicity that results in the release of cytochrome c. We observe that the release of eytochrome c from purified mitochondria is stimulated by the classical inducers of MPT, and is inhibited by the classical inhibitor of MPT, cyclosporin A (CsA). After induction of MPT, mitochondrial supernatants gained the activity to induce cleavage of caspase 3 (CPP32) in cytosolic extracts, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and was cancelled by immunodepletion of cytochrome c from the supernatants. After induction of MPT, mitochondrial supernatants mixed with or without cytosolic extract gained the activity to ladder nuclei, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and cancelled by immunodepletion of cytochrome c from the supernatants. These results demonstrate that the induction of MPT causes release of cytochrome c from mitochondria, which is required for the hallmarks of cytosolic and nuclear apoptosis, caspase 3 activation and nuclear laddering, and identify the MPT as a potential intracellular sensor of oxidants and other toxins, and as a target for the pharmacological inhibition of apoptosis.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 624-631 |
| Number of pages | 8 |
| Journal | Free Radical Biology and Medicine |
| Volume | 24 |
| Issue number | 4 |
| DOIs | |
| State | Published - Mar 1 1998 |
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Keywords
- Apoptosis
- Cytochrome c
- Free radical
- Mitochondria
- Permeability transition
ASJC Scopus subject areas
- Medicine(all)
- Toxicology
- Clinical Biochemistry
Cite this
Induction of the mitochondrial permeability transition causes release of the apoptogenic factor cytochrome C. / Yang, Joy C.; Cortopassi, Gino A.
In: Free Radical Biology and Medicine, Vol. 24, No. 4, 01.03.1998, p. 624-631.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Induction of the mitochondrial permeability transition causes release of the apoptogenic factor cytochrome C
AU - Yang, Joy C.
AU - Cortopassi, Gino A
PY - 1998/3/1
Y1 - 1998/3/1
N2 - It was recently reported that the mitochondrial protein cytochrome c is required for the induction of apoptosis, and that the overexpression of Bcl- 2 caused increased retention of this apoptogenic factor by mitochondria. Several cellular toxins, including H2O2, tBOOH and Ca++, induce the Mitochondrial Permeability Transition (MPT); we tested the possibility that MPT is an intracellular sensor of toxicity that results in the release of cytochrome c. We observe that the release of eytochrome c from purified mitochondria is stimulated by the classical inducers of MPT, and is inhibited by the classical inhibitor of MPT, cyclosporin A (CsA). After induction of MPT, mitochondrial supernatants gained the activity to induce cleavage of caspase 3 (CPP32) in cytosolic extracts, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and was cancelled by immunodepletion of cytochrome c from the supernatants. After induction of MPT, mitochondrial supernatants mixed with or without cytosolic extract gained the activity to ladder nuclei, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and cancelled by immunodepletion of cytochrome c from the supernatants. These results demonstrate that the induction of MPT causes release of cytochrome c from mitochondria, which is required for the hallmarks of cytosolic and nuclear apoptosis, caspase 3 activation and nuclear laddering, and identify the MPT as a potential intracellular sensor of oxidants and other toxins, and as a target for the pharmacological inhibition of apoptosis.
AB - It was recently reported that the mitochondrial protein cytochrome c is required for the induction of apoptosis, and that the overexpression of Bcl- 2 caused increased retention of this apoptogenic factor by mitochondria. Several cellular toxins, including H2O2, tBOOH and Ca++, induce the Mitochondrial Permeability Transition (MPT); we tested the possibility that MPT is an intracellular sensor of toxicity that results in the release of cytochrome c. We observe that the release of eytochrome c from purified mitochondria is stimulated by the classical inducers of MPT, and is inhibited by the classical inhibitor of MPT, cyclosporin A (CsA). After induction of MPT, mitochondrial supernatants gained the activity to induce cleavage of caspase 3 (CPP32) in cytosolic extracts, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and was cancelled by immunodepletion of cytochrome c from the supernatants. After induction of MPT, mitochondrial supernatants mixed with or without cytosolic extract gained the activity to ladder nuclei, and this gain of activity was inhibited by CsA pretreatment of mitochondria, and cancelled by immunodepletion of cytochrome c from the supernatants. These results demonstrate that the induction of MPT causes release of cytochrome c from mitochondria, which is required for the hallmarks of cytosolic and nuclear apoptosis, caspase 3 activation and nuclear laddering, and identify the MPT as a potential intracellular sensor of oxidants and other toxins, and as a target for the pharmacological inhibition of apoptosis.
KW - Apoptosis
KW - Cytochrome c
KW - Free radical
KW - Mitochondria
KW - Permeability transition
UR - http://www.scopus.com/inward/record.url?scp=0032031920&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032031920&partnerID=8YFLogxK
U2 - 10.1016/S0891-5849(97)00367-5
DO - 10.1016/S0891-5849(97)00367-5
M3 - Article
C2 - 9559874
AN - SCOPUS:0032031920
VL - 24
SP - 624
EP - 631
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
SN - 0891-5849
IS - 4
ER -