Abstract
Mitochondrial complex I has previously been shown to release superoxide exclusively towards the mitochondrial matrix, whereas complex III releases superoxide to both the matrix and the cytosol. Superoxide produced at complex III has been shown to exit the mitochondria through voltage dependent anion channels (VDAC). To test whether complex I-derived, mitochondrial matrix-directed superoxide can be released to the cytosol, we measured superoxide generation in mitochondria isolated from wild type and from mice genetically altered to be deficient in MnSOD activity (TnIFastCreSod2 fl/fl). Under experimental conditions that produce superoxide primarily by complex I (glutamate/malate plus rotenone, GM. +. R), MnSOD-deficient mitochondria release ∼4-fold more superoxide than mitochondria isolated from wild type mice. Exogenous CuZnSOD completely abolished the EPR-derived GM. +. R signal in mitochondria isolated from both genotypes, evidence that confirms mitochondrial superoxide release. Addition of the VDAC inhibitor DIDS significantly reduced mitochondrial superoxide release (∼75%) in mitochondria from either genotype respiring on GM. +. R. Conversely, inhibition of potential inner membrane sites of superoxide exit, including the matrix face of the mitochondrial permeability transition pore and the inner membrane anion channel did not reduce mitochondrial superoxide release in the presence of GM. +. R in mitochondria isolated from either genotype. These data support the concept that complex I-derived mitochondrial superoxide release does indeed occur and that the majority of this release occurs through VDACs.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 515-521 |
| Number of pages | 7 |
| Journal | Biochemical and Biophysical Research Communications |
| Volume | 422 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 8 2012 |
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Keywords
- Mitochondria
- Superoxide
- Voltage dependent anion channels
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Cell Biology
- Molecular Biology
Cite this
Complex I generated, mitochondrial matrix-directed superoxide is released from the mitochondria through voltage dependent anion channels. / Lustgarten, Michael S.; Bhattacharya, Arunabh; Muller, Florian L.; Jang, Youngmok C.; Shimizu, Takahiko; Shirasawa, Takuji; Richardson, Arlan; Van Remmen, Holly.
In: Biochemical and Biophysical Research Communications, Vol. 422, No. 3, 08.06.2012, p. 515-521.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Complex I generated, mitochondrial matrix-directed superoxide is released from the mitochondria through voltage dependent anion channels
AU - Lustgarten, Michael S.
AU - Bhattacharya, Arunabh
AU - Muller, Florian L.
AU - Jang, Youngmok C.
AU - Shimizu, Takahiko
AU - Shirasawa, Takuji
AU - Richardson, Arlan
AU - Van Remmen, Holly
PY - 2012/6/8
Y1 - 2012/6/8
N2 - Mitochondrial complex I has previously been shown to release superoxide exclusively towards the mitochondrial matrix, whereas complex III releases superoxide to both the matrix and the cytosol. Superoxide produced at complex III has been shown to exit the mitochondria through voltage dependent anion channels (VDAC). To test whether complex I-derived, mitochondrial matrix-directed superoxide can be released to the cytosol, we measured superoxide generation in mitochondria isolated from wild type and from mice genetically altered to be deficient in MnSOD activity (TnIFastCreSod2 fl/fl). Under experimental conditions that produce superoxide primarily by complex I (glutamate/malate plus rotenone, GM. +. R), MnSOD-deficient mitochondria release ∼4-fold more superoxide than mitochondria isolated from wild type mice. Exogenous CuZnSOD completely abolished the EPR-derived GM. +. R signal in mitochondria isolated from both genotypes, evidence that confirms mitochondrial superoxide release. Addition of the VDAC inhibitor DIDS significantly reduced mitochondrial superoxide release (∼75%) in mitochondria from either genotype respiring on GM. +. R. Conversely, inhibition of potential inner membrane sites of superoxide exit, including the matrix face of the mitochondrial permeability transition pore and the inner membrane anion channel did not reduce mitochondrial superoxide release in the presence of GM. +. R in mitochondria isolated from either genotype. These data support the concept that complex I-derived mitochondrial superoxide release does indeed occur and that the majority of this release occurs through VDACs.
AB - Mitochondrial complex I has previously been shown to release superoxide exclusively towards the mitochondrial matrix, whereas complex III releases superoxide to both the matrix and the cytosol. Superoxide produced at complex III has been shown to exit the mitochondria through voltage dependent anion channels (VDAC). To test whether complex I-derived, mitochondrial matrix-directed superoxide can be released to the cytosol, we measured superoxide generation in mitochondria isolated from wild type and from mice genetically altered to be deficient in MnSOD activity (TnIFastCreSod2 fl/fl). Under experimental conditions that produce superoxide primarily by complex I (glutamate/malate plus rotenone, GM. +. R), MnSOD-deficient mitochondria release ∼4-fold more superoxide than mitochondria isolated from wild type mice. Exogenous CuZnSOD completely abolished the EPR-derived GM. +. R signal in mitochondria isolated from both genotypes, evidence that confirms mitochondrial superoxide release. Addition of the VDAC inhibitor DIDS significantly reduced mitochondrial superoxide release (∼75%) in mitochondria from either genotype respiring on GM. +. R. Conversely, inhibition of potential inner membrane sites of superoxide exit, including the matrix face of the mitochondrial permeability transition pore and the inner membrane anion channel did not reduce mitochondrial superoxide release in the presence of GM. +. R in mitochondria isolated from either genotype. These data support the concept that complex I-derived mitochondrial superoxide release does indeed occur and that the majority of this release occurs through VDACs.
KW - Mitochondria
KW - Superoxide
KW - Voltage dependent anion channels
UR - http://www.scopus.com/inward/record.url?scp=84861938799&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861938799&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2012.05.055
DO - 10.1016/j.bbrc.2012.05.055
M3 - Article
C2 - 22613204
AN - SCOPUS:84861938799
VL - 422
SP - 515
EP - 521
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -