Mitochondria and Reactive Oxygen Species
Francesco Addabbo, Monica Montagnani, Michael S. Goligorsky
F
radical emission.” This review is focused on one component
of the noxious mitochondrial pathway: reactive oxygen species (ROS) from a mitochondrial perspective, which has
previously been extensively reviewed.4 Therefore, we shall
present the most recent findings but periodically offer historical perspective.
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ascination by the mitochondria, “the colonial posterity of
migrant prokaryocytes, probably primitive bacteria that
swam into ancestral precursors of our eukaryotic cells and
stayed there,”1 stems from the above-mentioned nebulous
endosymbiotic theory of their origin, as well as from the
growing realization of a very special role that they play in the
pathogenesis of diverse diseases.
These organelles generate energy primarily in the form of
the electrochemical proton gradient (⌬␮H⫹), which fuels
ATP production, ion transport, and metabolism.2 Generation
of this universal energy currency, ⌬␮H⫹, occurs through the
series of oxidative reactions conducted by the respiratory
chain complexes at the ion-impermeable, almost cholesterolfree inner membrane. Reduced nicotinamide adenine dinucleotide represents the entry point to the complex I (reduced
nicotinamide adenine dinucleotide:ubiquinone reductase),
whereas the reduced ubiquinol enters the respiratory chain in
the complex III (ubiquinol:cytochrome c [cyt-c] reductase) to
reduce cyt-c, the electron carrier to the complex IV, cyt-c
oxidase. Each of these steps generates ⌬␮H⫹ by electrogenic
pumping of protons from the mitochondrial matrix to the
intermembrane space and is coupled to electron flow, thus
generating the electric membrane potential of ⫺180 to ⫺220
mV and a pH gradient of 0.4 to 0.6 U across the inner
mitochondrial membrane resulting in the negatively charged
matrix side of the membrane and alkaline matrix. Ultimately,
accumulated ⌬␮H⫹ is converted into the influx of protons
into the matrix driving ATP synthesis or protein transport. In
addition, these end points are necessary for the execution of
2 major enzymatic metabolic pathways within the mitochondrial matrix: the tricarboxylic acid (TCA) oxidation cycle and
the fatty acid ␤-oxidation pathway. This intricate system
fueling cellular functions is as elegant as it is vulnerable:
practically every component of the system, from the electron
transport chain complexes to the permeability properties of
the membranes, is a target for various noxious stimuli, some
of which can be generated within mitochondria themselves.
The list of these noxious stimuli is too long to be recounted
here, and the interested reader may refer to a recent excellent
review.3 These ancestral oxygen-using proteobacterial invaders carried with them into eukaryotic cells not only evolutionary benefits but also potential side reactions, most dangerous of which are “exothermic oxygen combustion and free
Mitochondrial ROS and Actions
Mitochondrial ROS Generation
Mitochondrial respiration is the major source of ROS, with
0.2% of oxygen consumed being normally converted into
superoxide in a quiescent state.5 Unless adequately detoxified, superoxide causes mitochondrial oxidative stress and
may contribute to the decline in mitochondrial functions; this
general scenario is associated with a wide variety of pathologies. The transfer of electrons to oxygen, generating superoxide, is more likely when these redox carriers are abundantly
charged with electrons and the potential energy for transfer is
high, as reflected by a high mitochondrial membrane potential. Conversely, ROS generation is decreased when available
electrons are few and potential energy for the transfer is low.
Mitochondrial enzymes known to generate ROS through the
leak of electrons to molecular oxygen include the electrontransport chain (ETC) complexes I, II, and III6 – 8; the TCA
cycle enzymes aconitase 2 and ␣-ketoglutarate dehydrogenase9; pyruvate dehydrogenase and glycerol-3-phosphate dehydrogenase10,11; dihydroorotate dehydrogenase; the monoamine oxidases A and B12,13; and cytochrome b5 reductase.4
One of the major drawbacks of the previous work in this
field was considered to be the lack of in vivo data on ROS
production. Therefore, perhaps the most notable breakthrough in the field is related to the recent demonstration of
the kinetics of superoxide production in mitochondria of
living cells or organs.14 In cultured excitable and nonexcitable
cells transfected with a circularly permuted yellow fluorescence protein, a novel biosensor of superoxide that is unaffected by hydrogen peroxide, peroxynitrite, hydroxyl radical,
or NO, investigators detected fluorescence flashes arising
from individual or a group of functionally coupled mitochondria. Flashes of superoxide production peaked in 3.5 seconds
and dissipated with a half-time of 8.6 seconds, occurred
randomly, and the frequency and amplitude were reduced by
Received January 31, 2009; first decision February 18, 2009; revision accepted April 3, 2009.
From the Departments of Medicine and Pharmacology (F.A., M.S.G.), Renal Research Institute, New York Medical College, Valhalla; and the
Department of Pharmacology and Human Physiology (F.A., M.M.), University of Bari Medical School, Bari, Italy.
Correspondence to Michael S. Goligorsky, Renal Research Unit, Department of Medicine and Pharmacology, New York Medical College, 95
Grasslands Rd, Valhalla, NY 10595. E-mail Michael㛭[email protected]
(Hypertension. 2009;53:00-00.)
© 2009 American Heart Association, Inc.
Hypertension is available at http://hyper.ahajournals.org
DOI: 10.1161/HYPERTENSIONAHA.109.130054
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a superoxide dismutase (SOD) mimetic or by a superoxide
scavenger tiron.14 These superoxide flashes were triggered by
the transient openings of mitochondrial permeability transition
pores (mPTPs) but were unrelated to Ca⫹⫹ sparks. Transient
mPTP-initiated superoxide flashes required functional ETC
and were ATP dependent. Superoxide flashes coincided with
transient dissipation of mitochondrial membrane potential,
matrix acidosis, and mitochondrial swelling. Anoxia or mild
hypoxia decreased the frequency of superoxide flashes in
cardiac myocytes, suggesting that elevated ROS levels found
under these conditions originate extramitochondrially or are
attributed to the defective antioxidant defense. However, on
reoxygenation (the period of enhanced vulnerability of the
cells), superoxide flash activity increased, and adenosine
preconditioning treatment prevented it. This description of
quantal, stochastic, and transient superoxide flashes driven by
the flickers of mPTPs in quiescent cells should profoundly
change the current interpretation of such events as being
necessarily pathological, emphasizing the role of graded
spatiotemporary ROS production in the normal processes of
cell signaling via kinases, phosphatases, channels, and transporters, as well as maintenance of ROS scavenging and
detoxifying systems. In addition, these discoveries feed into
the deeper appreciation of the complexity of mitochondrial
ROS production. Integrating these studies into the broad
canvas of the existing knowledge will represent the next
challenge. Clearly, the bidirectional effects of ROS generated
in the cytosol on mitochondria and ROS generated in mitochondria on cytosolic systems will receive additional details.
Furthermore, the concept of ROS-induced ROS release involving induction of the mitochondrial permeability transition15 is further supported by these new studies.14
Another powerful source of mitochondrial ROS production
is represented by the mitochondrial NO synthase (NOS).16 In
hepatocytes and cardiomyocytes,17 NOS is localized inside
mitochondria, whereas in endothelial cells it is docked via the
autoinhibitory domain to the cytoplasmic face of the outer
mitochondrial membrane.17 Physiological production of NO
by the enzyme is credited with the minute-to-minute regulation of cyt-c oxidase activity: elevated NO reduces cyt-c
oxidase activity by S-nitrosylation of cysteine residues of
complex IV and complex I.16 –20 In the uncoupled state,
endothelial NOS (eNOS) generates superoxide anion.21 Uncoupling of O2 reduction from NO synthesis does not require
homodimer dissociation and monomerization of the enzyme,
rather, it occurs as a result of the substrate and tetrahydrobiopterin deficiency, resulting in the preferential generation
of superoxide over NO, enhanced generation of peroxynitrite
with further depletion of tetrahydrobiopterin oxidation to
dihydrobiopterin, and reduced NO levels. Apart from multitude of pathological states leading to the uncoupling of
eNOS, eg, in states of endothelial dysfunction, partial uncoupling occurs in the eNOS Glu298Asp polymorphism.22
Mitochondrial Antioxidant Defense Systems
Mitochondria are equipped with an impressive array of enzymatic and nonenzymatic antioxidant defense systems posed to
detoxify the ROS generated by the reactions described above.
Nonenzymatic components of the system include hydrophilic
and lipophilic radical scavengers, eg, cyt-c, ␣-tocopherol, ascorbic acid, reduced coenzyme Q10, and glutathione. Enzymatic
components include manganese SOD,23 catalase, glutathione
peroxidase, and phospholipid hydroperoxide glutathione peroxidase (reduces hydroperoxide groups on phospholipids,
lipoproteins, and cholesteryl esters),24 as well as enzymes
involved in the reduction of oxidized forms of small antioxidant molecules, eg, glutathione reductase; responsible for the
maintenance of protein thiols, eg, thioredoxin reductase; or
glutaredoxin reductases and peroxiredoxin.25 The regeneration of glutathione by glutathione reductase and reduced
thioredoxin 2 by thioredoxin reductase depends on NADPH.
For all of these enzymes, mutations in their corresponding
genes have been associated with idiopathic cardiomyopathy,
neurological diseases, impaired glucose metabolism, and
cancer.26 –28 In structurally and functionally intact mitochondria, antioxidant defense capacity balances ROS generation,
limiting net ROS availability. Decreased antioxidant defense
capacity is a prerequisite for increased net ROS production
and oxidative stress.
ROS Targets in Mitochondria (Lipids
and Proteins)
ROS instability and inability to permeate lipid membranes
usually provide an effective shield against propagating damage. However, through reactions with polyunsaturated fatty
acids, they generate lipid hydroperoxides and ␣ , ␤ unsaturated aldehydes, eg, 4-hydroxy-2-nonenal, which are
highly electrophilic, stable, readily propagating between cellular compartments, and capable of reacting with proteins and
nucleic acids.29 This chain reaction of lipid peroxidation
accounts for the role played by ROS in the pathogenesis of
atherosclerosis, ischemia/reperfusion injury, and stressinduced premature senescence.
Aconitase-2
Aconitase-2 (ACO-2) is a mitochondrial enzyme that catalyzes the isomerization of citrate to isocitrate in the Krebs
cycle. It is an Fe-S containing protein. The structural predilection of the Fe-S center in ACO-2 to ROS and peroxynitrite30 may, in part, explain its selective vulnerability. ACO-2
has been found previously to be specifically targeted by
oxidative damage during aging.31 Prolonged exposure of
mitochondria to oxidants results in disassembly of the [4Fe4S]2⫹ cluster, carbonylation, and degradation of the enzyme,32 potentially establishing the link between oxidative
stress and enzyme inactivation, as detected during cardiac
ischemia/reperfusion injury,33 and an eventual reduction in
ACO-2 abundance. In a recent study, we established a novel
animal model of asymptomatic normotensive endothelial
dysfunction by pharmacologically uncoupling eNOS and
identified inhibition of the Krebs cycle and reduction in
mitochondrial mass as its early manifestations.21
Specifically, a proteome-wide screen of microvasculature
using 2D electrophoresis and mass spectroscopy revealed
that, in animals treated with subpressor doses of NG-monomethyl-L-arginine (L-NMMA), 2 mitochondrial enzymes,
ACO-2 and enoyl coenzyme A (CoA) hydratase-1 (ECHS-1),
were depleted in the microvasculature, affecting the Krebs
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cycle and leading to the accumulation of lactate. Pharmacological uncoupling of eNOS resulting in enhanced generation
of superoxide anion, rather than a complete inhibition of its
activity, was found responsible for this phenotype. Considering the uncoupling of eNOS and enhanced mitochondrial
generation of ROS (as judged by the MitoSox fluorescence in
the case of L-NMMA treatment), it is conceivable that the
combination of oxidative stress and reduced NO bioavailability culminates in a unique proteomic profile: reduced mitochondrial mass and selective depletion of ⱖ2 key enzymes of
the Krebs cycle, ACO-2 and ECHS-1. The decrease in
ACO-2 should inhibit the Krebs cycle. The excess pyruvate is
converted to lactate by lactate dehydrogenase, as is the case in
L-NMMA-treated mice. In addition, inhibition of the Krebs
cycle is compounded by the depletion of ECHS-1, which
catalyzes the second step of ␤-oxidation in fatty acid metabolism, the process by which fatty acids in the form of
acyl-CoA are processed in mitochondria and/or peroxisomes
to generate acetyl-CoA, the entry molecule for the Krebs
cycle. Our recent studies provide evidence that no detectable
tissue hypoxia develops in this model using subpressor doses
of L-NMMA.34 Importantly, this indicates that the observed
switch to glycolytic metabolism in the face of relative
normoxia makes this metabolic profile similar to the Warburg
effect, the phenomenon of preferential glycolysis in tumor
cells35 (vide infra). In this context, the role of NO appears to
be complex. Acute actions of NO result in “metabolic hypoxia”
by inhibition of mitochondrial electron transport. Chronic uncoupling of NOS, on the other hand, confers the same end result
through selective depletion of ACO-2 and ECHS-1. We advocate, therefore, that inhibition of the Krebs cycle may herald the
development of endothelial dysfunction.
Cardiolipin-Cyt c and Apoptosis
An anionic phospholipid of the inner mitochondrial membrane (IMM) enriched at contact sites with the outer mitochondrial membrane, cardiolipin, represents another prime
target of oxidative stress. Under normal conditions, cardiolipin “fixes” cyt-c to the IMM. Oxidation of the highly
unsaturated acyl chains of cardiolipin reduces its binding
affinity for cyt-c and liberates it from the IMM. This event, in
conjunction with permeabilization of the outer mitochondrial
membrane by proapoptotic members of the Bcl-2 family of
proteins, results in the release of cyt-c into the cytosol,
formation of apoptosome, and activation of the caspase
cascade culminating in apoptosis.36 Interestingly, contact
sites between the outer mitochondrial membrane and IMM
also contain hexokinases II and III, bound to the cytoplasmic
face of the voltage-dependent anion channel.37 In this
voltage-dependent anion channel– bound state, hexokinases
prevent cyt-c release from mitochondria, thus conferring an
antiapoptotic effect. This bound state of hexokinases also
supports the coupling of intramitochondrial and extramitochondrial metabolism via efficient adenine nucleotide exchange; dissociation of hexokinases from mitochondria promotes uncoupling of mitochondrial metabolism from the cell
requirements and facilitates apoptosis.38
Mitochondria and ROS
3
Consequences of Mitochondrial
Oxidative Stress
Oxidative Stress-Mediated Autophagy
The role of mitochondria in cells commitment to caspasedependent programmed cell death is well established, whereas
insights into caspase-independent mechanisms of cell death
emerged recently. Autophagy is one of the defense mechanisms protecting cells against oxidative stress. It is a regulated lysosomal pathway involved in the degradation and
recycling of oxidized proteins and damaged organelles in the
aging cells.39 – 41 There is accumulating evidence that autophagic processing of damaged or excessive organelles, eg,
peroxisomes, endoplasmic reticula, and mitochondria, can
occur in response to ROS.42,43 Excessive ROS in quiescent
mitochondria pose the risk to this organelle and to the
viability of the cell through opening of mitochondrial membrane channels, including the mPTP and the inner membrane
anion channel,44 leading to the collapse of mitochondrial
membrane potential and further transient increase in ROS
generation by the electron transfer chain.14 These events may
result in autophagy, apoptosis, or necrosis.44
In a recent report, Chen et al45 have demonstrated that
complex I inhibitor rotenone and complex II inhibitor thenoyl
trifluoroacetone induce ROS-mediated autophagy, contributing to cell death in transformed and cancer cell lines. By
contrast, in primary astrocytes, rotenone and thenoyl trifluoroacetone failed to induce autophagy. This suggests that the
inhibition of mitochondrial ETC selectively induces autophagic cell death, mediated by ROS, in immortalized and cancer
cells. These findings led the authors to indicate that the
inhibition of the mitochondrial ETC can specifically induce
autophagic cell death in cancer cells but not in other cell
types, providing a new potential target to fight cancer cells.
Another recent finding has demonstrated that apoptosis and
autophagy could be induced by photosensitization of mitochondria or endoplasmic reticula.46 Sasnauskiene et al47 used
low and intermediate energy photodynamic treatments to
stimulate mitochondria ROS production in cultured human
epidermoid carcinoma A-431 cells. The approach used was
based on the visible light excitation of a mitochondrialocalized lipophilic cationic photosensitizer, Safranin O, leading to generation of ROS and oxidative damage of cellular
components. In this study, low energy photodynamic treatment of cells failed to show hallmarks of apoptosis, necrosis,
or senescence, and the detected loss of viability and reduced
proliferation of the cells were ascribed to the enhanced
autophagy.47
Mitochondrial Biogenesis and
“Stress-Response Hormesis”
The former refers to processes regulating mitochondrial mass,
whereas the latter refers to the induction of stress-protective
mechanisms.48 Interestingly, both processes are interconnected. There are emerging data that a nonlethal oxidative
stress may stimulate mitochondrial biogenesis via activation
of leucine zipper transcription factors, nuclear factor-E2–
related factor and ATF4, which regulate the expression of
antioxidant response element– containing genes, eg, glutathi-
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June 2009
one S-transferase, glutathione peroxidase, glutathione reductase (all involved in glutathione biosynthesis and cycling),
and heme oxygenase 1, among others.49 This process is
governed, at least in part, by the mitochondrial ROS stimulating nuclear factor-E2–related factor binding to the promoter region (rich in antioxidant response element motifs) of
the nuclear respiratory factor 1 in the Akt-dependent derepression of nuclear factor-E2–related factor nuclear translocation.50 Activation of nuclear respiratory factor 1 is a
prerequisite for transcriptional activation of mitochondrial
transcription factor A and induction of mitochondrial DNA
(mtDNA) replication/transcription and mitochondrial biogenesis.51,52 Another recently discovered mechanism stimulating
mitochondrial biogenesis in response to the etoposideinduced ataxia telangiectasia mutated– dependent pathway is
attributed to AMP-activated protein kinase activation.53
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Mitochondrial Oxidative Stress in
Pathological Conditions
Warburg Effect Is an Early Manifestation of
Dysfunctional Endothelial Cells
Since Warburg’s discovery of enhanced glucose uptake by
and preferential glycolytic metabolism in tumor cells even
during normoxia (aerobic glycolysis),35 mechanistic explanations of this phenomenon have been offered.54 These include
mutations promoting glycolysis in crucial genes, eg, Ras, Akt
kinase, HIF-1, Myc transcription factor, and loss of the tumor
suppressor protein p53, to name a few.55–58 Therapeutic
implications of these investigations using inhibitors of glycolytic enzymes have been incorporated into the antineoplastic arsenal.59 Thus, the Warburg effect was perceived as a
tumor-specific type of metabolic disturbances.
Our in vivo and in vitro findings in vascular endothelial
cells subjected to elevated levels of L-NMMA or asymmetrical dimethylarginine showed a similar glycolytic switch.21
Using the same model of endothelial dysfunction,34,60 we
have shown that nonpressor doses of NOS inhibitors result in
the upregulation of collagen XVIII and its C-terminal fragment, endostatin; microvascular rarefaction readily detectable
in the renal medulla; and ultrastructural changes in microvascular endothelia but no appreciable degree of hypoxia, as
judged by the lack of pimonidazole retention.34 Yet, microvasculature obtained from these mice showed markedly
depressed expression of the key enzyme of the Krebs cycle,
ACO-2; reduced oxidative phosphorylation; and enhanced
glycolysis, as judged by the accumulation of lactate in the
extracellular fluid and by the inability of cells to survive in
the glucose-to-galactose substituted medium21 (Figure). This
is further supported by the fact that ␣-ketoglutarate, a
downstream substrate bypassing mitochondrial enzymatic
block at the level of isocitrate formation, partially restored
cell viability in the glucose-free medium. Intriguingly, this
normoxic glycolysis in dysfunctional endothelial cells was
initiated under the circumstances of the eNOS uncoupling
and asymmetrical dimethylarginine/L-NMMA-induced mitochondrial oxidative stress,21 thus expanding the Warburg
effect considered previously to be a hallmark of tumors.
Glucose uptake
Glucose uptake
Glucose uptake
p53
TIGAR
18 ATP
LDH
Oxaloacetate
Acetyl- CoA
PDK- 1
Citrate
Malate
TCA cycle
Fatty acids
Lactate
2 ATP
Acyl-CoA
Citrate
ECHS-1
Acetyl- CoA
ACO- 2
Isocitrate
Isocitrate
Fumarate
Alpha- KG
Alpha- KG
Succinate
Succinyl- CoA
Normoxic control
Tumor cell
Early endothelial
dysfunction
Figure. Schematic illustration of the Warburg effect in tumor
cells and in early asymptomatic endothelial cell dysfunction.
Under normoxic conditions, intact cells metabolize glucose
through the TCA cycle. In contrast, tumor cells avidly uptake
glucose and exhibit blockade of oxidative phosphorylation at
the entry point of conversion of lactate to pyruvate because of
the inhibition of pyruvate dehydrogenase kinase-1 (PDK-1). In
addition, mutations of p53 result in the reduced signaling
through TP53-induced glycolysis and apoptosis regulator
(TIGAR), which normally inhibits the glycolytic pathway. As a
result, lactate is produced in excessive amounts, all hallmarks of
the Warburg effect. Interestingly, pharmacological inhibitors of
lactate dehydrogenase (LDH) may reverse glucose metabolism
to oxidative phosphorylation. At the early stages of endothelial
cell dysfunction, similar to tumor cells, oxidative phosphorylation
is suppressed and glycolysis enhanced, resulting in overproduction of lactate. Under these conditions, blockade of the TCA
cycle occurs at the level of the catalyzed by ECHS-1 conversion
of acyl-CoA to acetyl-CoA, the point of entry to the cycle, and
at the level of the conversion of citrate to isocitrate (because of
the depletion of aconitase 2). This block in the TCA cycle can
be resolved by bypassing the deficient aconitase 2 with the
downstream substrate, ␣-ketoglutarate (Alpha-KG). These new
data on the early metabolic stigmata of dysfunctional endothelia
vis-à-vis tumor cells emphasize their similarities and
distinctions.
It is interesting that metformin, a widely used antidiabetic
drug, inhibits complex I of the respiratory chain and induces
glycolysis and lactate production in a p53- and AMPactivated protein kinase– dependent manner.61 It remains to
be elucidated whether this effect is accompanied by signs of
endothelial dysfunction.
Oxidative Stress Implications in Diabetes Mellitus
and Cardiovascular Complications
The role played by oxidative stress in the development of
insulin resistance and metabolic syndrome has been well
documented: excessive production of oxidants, decreased NO
bioavailability, and decreased local antioxidant capacity in
the vasculature.62– 64 It is important to recognize that excess
superoxide itself can directly inhibit critical endothelial enzymes. One such targets is eNOS, an important antiatherogenic enzyme with great relevance to diabetic macrovascular
disease: its activity and coupling are dramatically inhibited in
animal models of diabetes mellitus and in diabetic patients.65,66 Conventional antioxidants are unable to scavenge
the hyperglycemia-induced superoxide anion, the rationale
being that antioxidants neutralize reactive oxygen molecules
on a 1-to-1 basis, thus becoming exhausted by the continuous
production of the superoxide. Salvemini et al67 have shown
that a new type of antioxidant, a catalytic antioxidant, eg, a
SOD/catalase mimetic, may be more effective because it works
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continuously like the enzymes. Hyperglycemia-induced reactive
oxygen overproduction directly reduces eNOS activity in diabetic aortas by 65%. However, when these diabetic animals
are treated with a SOD/catalase mimetic, there is no reduction
in activity of this antiatherogenic enzyme. These data
strongly suggest that therapeutic correction of diabetes mellitus–induced superoxide production may be a powerful new
approach for preventing diabetic complications.
Giardino et al68 have demonstrated that, in cultured bovine
aortic endothelial cells, hyperglycemia increases the production of ROS, and a few years later, in a very elegant fashion,
the same group has demonstrated that Krebs cycle is the
source of increased ROS generation induced by hyperglycemia.69 Pharmacological inhibition of electron transport chain
complex II with thenoyl trifluoroacetone or abolishing the
mitochondrial membrane proton gradient by carbonyl cyanide m-chlorophenylhydrazone, an uncoupler of oxidative
phosphorylation, completely prevented hyperglycemiainduced ROS; these results were buttressed using molecular
biology tools.69 One of the most notable findings is that
normalizing levels of mitochondrial ROS with each of these
agents prevented glucose-induced activation of protein kinase
C, formation of advanced glycation end products, sorbitol
accumulation, and nuclear factor ␬B activation, indicating a
single unifying mechanism of induction and a causative role
for mitochondrial superoxide in the above-mentioned
hyperglycemia-induced metabolic abnormalities. These data
provided the basis for the development of new drugs to
prevent cardiovascular complications in diabetic subjects.69
Another prominent mechanism for the development and
perpetuation of mitochondrial dysfunction is related to the
induction of an IMM protein, uncoupling protein 2 (UCP2).70
Oxidative stress results in the accumulation of UCP2 in
mitochondria leading to the inward proton leak, which
competes with the function of ATP synthase and results in a
reduction of ATP synthesis from ADP. This situation can be
modeled in vitro by application of rotenone, antimycin A, or
diethyldithiocarbamate, all increasing mitochondrial superoxide production, whereas oxidants producing outside mitochondria did not affect UCP2 abundance.71 This process did
not require a parallel increase in ucp2 gene expression or
mRNA abundance; rather, it is attributed to enhanced translational efficiency and stabilization of UCP2. Overexpression
of UCP2 in cultured pancreatic ␤-cells reduces glucoseinduced insulin secretion,72 whereas inactivation of the ucp2
gene in vivo enhances insulin secretion.73 This latter mechanism is critically involved in the development of insulin
resistance and type 2 diabetes mellitus.74
Aging
Mitochondrial ROS have been proposed to contribute to
aging through the accumulation of mtDNA mutations. Human mtDNA is a circular molecule of 16 569 bp that encodes
13 polypeptide components of the respiratory chain, as well
as 2 ribosomal RNAs and 22 tRNAs necessary to support
intramitochondrial protein synthesis essential for electron
transport and ATP generation by oxidative phosphorylation
of ADP.75 mtDNA represents a critical cellular target for
oxidative damage that could lead to lethal cell injury through
Mitochondria and ROS
5
the loss of electron transport, mitochondrial membrane potential, and ATP generation. Furthermore, because of the lack
of protective histones and its close proximity to the electron
transport chain, mtDNA is especially susceptible to be
attacked by ROS (the level of oxidatively modified bases in
mtDNA is several-fold higher than that in nDNA). Inherited
mutations in mtDNA are known to cause a variety of
diseases, most of which affect tissues with high energy
requirements, eg, the brain and muscles.76,77 Somatic mtDNA
mutations acquired during a life span contribute to the
physiological decline that occurs with aging. Among the most
studied mtDNA mutations accumulating with aging, there are
large-scale deletions78 and point mutations accumulating in
specific “hot spots” in the mtDNA control region.79 The
accumulation of these deletions and point mutations with
aging correlates with a progressive decline in mitochondrial
function. Recently, several groups have addressed the issue of
causation generating mtDNA mutations experimentally.80 In
mtDNA-mutator mice, expression of defective mtDNA polymerase resulted in decreased respiratory enzyme activity,
ATP production, and life span.81 Another independent
mtDNA-mutator mouse showed a similar marked increase in
mtDNA mutations, progeric features, and early mortality.82
Thus, the effects of mtDNA mutations in these mice do not
seem to be mediated through ROS production; rather, these
models may shed light on the events subsequent to increased
generation of mitochondrial ROS and their effect on mtDNA.
It has been demonstrated that enhancing mitochondrial antioxidant defenses can increase longevity. In Drosophila,
overexpression of the mitochondrial antioxidant enzymes
manganese SOD7 and methionine sulfoxide reductase83 prolong life span. This strategy is most successful in short-lived
strains of Drosophila but does not guarantee effect in already
long-lived strains. However, Schriner et al84 generated transgenic overexpressing catalase experimentally targeted to
peroxisomes, nuclei, or mitochondria. The mitochondrially
targeted construct provided the maximal benefit, increasing
median and maximal life span by 20% in an already longlived murine strain. Catalase overexpression was also associated with a reduction of hydrogen peroxide production and
oxidative inactivation of ACO-2 in isolated cardiac mitochondria; DNA oxidation and levels of mitochondrial deletions were reduced in skeletal muscle; and cardiac pathology,
arteriosclerosis, and cataract development were delayed.84
Hypertension and Mitochondrial ROS
Among many sources of increased vascular ROS production
in hypertension, eg, NADPH oxidase, lipoxygenases, cyclooxygenases, xanthine oxidoreductase, cytochrome P450 enzymes, and eNOS, mitochondrial ROS overproduction plays
an important role. The subject of mitochondrial ROS and
hypertension has been reviewed previously.85– 87 In spontaneously hypertensive rats, mitochondrial ROS production in the
rostral ventrolateral medulla is increased, and administration
of coenzyme Q10 restores ETC and attenuates hypertension.88
A relay mechanism propagating ROS generation from the
cytoplasm to the mitochondria has been described in angiotensin II–induced hypertension: increased mitochondrial hydrogen peroxide production could be attenuated by an inhib-
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June 2009
itor of NADPH oxidase or by depleting the p22(phox) subunit
of NADPH oxidase, among others.89 The role played by
angiotensin II in developing mitochondriopathy has been
advanced recently by Benigni et al.90 Deletion of the Agtr-1a
gene resulted in the reduced age-related cardio-renal complications, improved mitochondrial biogenesis, and increased
longevity in mice.
Therapeutic Implications
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Pharmacological tools available to regulate mitochondrial
respiratory chain complexes and mPTP, both targets of
anticancer therapy, are comprehensively reviewed elsewhere
and are beyond the scope of this essay.91 Suffice it to mention
that dietary supplement with several metal ion cofactors like
selenium, vanadium, chromium, zinc, copper, and manganese, together with vitamins C, A, and E is a necessary
prerequisite for successful maintenance of antioxidants. Furthermore, coenzyme Q10 has been shown to reduce mitochondrial ROS generation. Here, we briefly recount a few pharmacological tools to counter mitochondrial oxidative stress
while bearing in mind the “antioxidant paradox,” a relatively
poor performance of antioxidants in scavenging ROS in vivo.
One of the strategies to target antioxidants to mitochondria is
based on the selective accumulation of positively charged
lipophilic substances, like triphenylphosphonium. By conjugating this carrier to ␣-tocopherol (MitoVit E) or to ubiquinone (MitoQ), these antioxidants can be effectively delivered
into mitochondria.92
Another group of mitochondrial antioxidants has been used
in studies by Liu et al.93 These include mitochondrial metabolites acetyl-L-carnitine and lipoic acid and antioxidants
␣-phenyl-N-t-butyl nitrone (a widely used spin-trapping
agent) and N-t-butyl hydroxylamine, which have been shown
to improve mitochondrial ultrastructure and function in aged
rodents and to delay cell senescence in vitro.
Modest induction (but not a prolonged one) of mitochondrial biogenesis has been shown to promote mitochondrial
biogenesis in the heart94 and can be readily achieved using
peroxisome proliferator-activated receptor-␥ coactivators.
Another compound acting on mitochondrial biogenesis and
exhibiting antioxidant properties is the plant-derived polyphenol resveratrol (reviewed in Reference 95). It improves
mitochondrial functions in the metabolic syndrome by acting
on AMP-activated protein kinase and activating sirtuin 1 and
peroxisome proliferator-activated receptor-␥-1␣.96
Recent studies have demonstrated that nitrite anion results
in the reduction of ROS produced at the mitochondrial site97
by inhibiting complex I activity of ETC under conditions of
postischemic oxidative stress (but not under normoxic conditions) and by reduction of activated mPTPs. Nitrite anion
acts, most probably, via conversion to NO either through
direct reduction or enzymatically by xanthine oxidoreductase,
deoxyhemoglobin, or deoxymyoglobin.98 This approach may
represent a valuable pharmacological tool to prevent acute
postischemic mitochondrial oxidative stress but may potentially have deleterious effects on chronic administration.
There is clearly a long and tortuous path ahead of us in
creating highly efficient targeted antioxidants.
Acknowledgments
We apologize for the inability to mention many relevant studies not
through neglect but because of the space limitation.
Sources of Funding
Studies performed in our laboratories were supported in part by
National Institutes of Health grants DK54602, DK052783, and
DK45462; the Westchester Artificial Kidney Foundation (to
M.S.G.); and Juvenile Diabetes Research Foundation Career Development Award grant 2-2006-32 (to M.M.).
Disclosures
None.
References
1. Thomas L. The Lives of a Cell: Notes of a Biology Watcher. Toronto,
Canada: Bantam Books, Inc; 1975.
2. Skulachev VP. Chemiosmotic concept of the membrane bioenergetics:
what is already clear and what is still waiting for elucidation? J Bioenerg
Biomembr. 1994;26:589 –598.
3. Wallace KB, Starkov AA. Mitochondrial targets of drug toxicity. Annu
Rev Pharmacol Toxicol. 2000;40:353–388.
4. Lin MT, Beal MF. Mitochondrial dysfunction and oxidative stress in
neurodegenerative diseases. Nature. 2006;443:787–795.
5. St-Pierre J, Buckingham JA, Roebuck SJ, Brand MD. Topology of
superoxide production from different sites in the mitochondrial electron
transport chain. J Biol Chem. 2002;277:44784 – 44790.
6. Cadenas E, Davies KJ. Mitochondrial free radical generation, oxidative
stress, and aging. Free Radic Biol Med. 2000;29:222–230.
7. Sun J, Trumpower BL. Superoxide anion generation by the cytochrome
bc1 complex. Arch Biochem Biophys. 2003;419:198 –206.
8. Zhang L, Yu L, Yu CA. Generation of superoxide anion by succinatecytochrome c reductase from bovine heart mitochondria. J Biol Chem.
1998;273:33972–33976.
9. Orrenius S, Gogvadze V, Zhivotovsky B. Mitochondrial oxidative stress:
implications for cell death. Annu Rev Pharmacol Toxicol. 2007;47:
143–183.
10. Miwa S, Brand MD. The topology of superoxide production by complex
III and glycerol 3-phosphate dehydrogenase in Drosophila mitochondria.
Biochim Biophys Acta. 2005;1709:214 –219.
11. Mracek T, Pecinova A, Vrbacky M, Drahota Z, Houstek J. High efficiency of ROS production by glycerophosphate dehydrogenase in mammalian mitochondria. Arch Biochem Biophys. 2009;481:30 –36.
12. Bortolato M, Chen K, Shih JC. Monoamine oxidase inactivation: from
pathophysiology to therapeutics. Adv Drug Deliv Rev. 2008;60:
1527–1533.
13. Vindis C, Seguelas MH, Lanier S, Parini A, Cambon C. Dopamine
induces ERK activation in renal epithelial cells through H2O2 produced
by monoamine oxidase. Kidney Int. 2001;59:76 – 86.
14. Wang W, Fang H, Groom L, Cheng A, Zhang W, Liu J, Wang X, Li K,
Han P, Zheng M, Yin J, Mattson MP, Kao JP, Lakatta EG, Sheu SS,
Ouyang K, Chen J, Dirksen RT, Cheng H. Superoxide flashes in single
mitochondria. Cell. 2008;134:279 –290.
15. Zorov DB, Filburn CR, Klotz LO, Zweier JL, Sollott SJ. Reactive oxygen
species (ROS)-induced ROS release: a new phenomenon accompanying
induction of the mitochondrial permeability transition in cardiac
myocytes. J Exp Med. 2000;192:1001–1014.
16. Poderoso JJ, Carreras MC, Lisdero C, Riobo N, Schopfer F, Boveris A.
Nitric oxide inhibits electron transfer and increases superoxide radical
production in rat heart mitochondria and submitochondrial particles. Arch
Biochem Biophys. 1996;328:85–92.
17. Gao S, Chen J, Brodsky SV, Huang H, Adler S, Lee JH, Dhadwal N,
Cohen-Gould L, Gross SS, Goligorsky MS. Docking of endothelial nitric
oxide synthase (eNOS) to the mitochondrial outer membrane: a pentabasic amino acid sequence in the autoinhibitory domain of eNOS targets
a proteinase K-cleavable peptide on the cytoplasmic face of mitochondria.
J Biol Chem. 2004;279:15968 –15974.
18. Jekabsone A, Ivanoviene L, Brown GC, Borutaite V. Nitric oxide and
calcium together inactivate mitochondrial complex I and induce cytochrome c release. J Mol Cell Cardiol. 2003;35:803– 809.
19. Brown GC, Borutaite V. Inhibition of mitochondrial respiratory complex
I by nitric oxide, peroxynitrite and S-nitrosothiols. Biochim Biophys Acta.
2004;1658:44 – 49.
Addabbo et al
Downloaded from http://hyper.ahajournals.org/ by guest on June 17, 2017
20. Clementi E, Brown GC, Feelisch M, Moncada S. Persistent inhibition of
cell respiration by nitric oxide: crucial role of S-nitrosylation of mitochondrial complex I and protective action of glutathione. Proc Natl Acad
Sci U S A. 1998;95:7631–7636.
21. Addabbo F, Ratliff B, Park HC, Kuo MC, Ungvari Z, Ciszar A, Krasnikof
B, Sodhi K, Zhang F, Nasjletti A, Goligorsky MS. The Krebs cycle and
mitochondrial mass are early victims of endothelial dysfunction: proteomic approach. Am J Pathol. 2009;174:34 – 43.
22. Cherney DZ, Scholey JW, Zhou J, Zimpelmann J, Kennedy C, Burns KD,
Lai V, Miller JA. Endothelial nitric oxide synthase gene polymorphisms
and the renal hemodynamic response to L-arginine. Kidney Int. 2009;75:
327–332.
23. Fridovich I. Superoxide anion radical (O2-.), superoxide dismutases, and
related matters. J Biol Chem. 1997;272:18515–18517.
24. Pushpa-Rekha TR, Burdsall AL, Oleksa LM, Chisolm GM, Driscoll DM.
Rat phospholipid-hydroperoxide glutathione peroxidase. cDNA cloning
and identification of multiple transcription and translation start sites.
J Biol Chem. 1995;270:26993–26999.
25. Maher P. Redox control of neural function: background, mechanisms, and
significance. Antioxid Redox Signal. 2006;8:1941–1970.
26. Turnbull J, Lohi H, Kearney JA, Rouleau GA, Delgado-Escueta AV,
Meisler MH, Cossette P, Minassian BA. Sacred disease secrets revealed:
the genetics of human epilepsy. Hum Mol Genet. 2005;14(spec No. 2):
2491–2500.
27. Toye AA, Lippiat JD, Proks P, Shimomura K, Bentley L, Hugill A, Mijat
V, Goldsworthy M, Moir L, Haynes A, Quarterman J, Freeman HC,
Ashcroft FM, Cox RD. A genetic and physiological study of impaired
glucose homeostasis control in C57BL/6J mice. Diabetologia. 2005;48:
675– 686.
28. Parsons DW, Jones S, Zhang X, Lin JC, Leary RJ, Angenendt P, Mankoo
P, Carter H, Siu IM, Gallia GL, Olivi A, McLendon R, Rasheed BA, Keir
S, Nikolskaya T, Nikolsky Y, Busam DA, Tekleab H, Diaz LA Jr,
Hartigan J, Smith DR, Strausberg RL, Marie SK, Shinjo SM, Yan H,
Riggins GJ, Bigner DD, Karchin R, Papadopoulos N, Parmigiani G,
Vogelstein B, Velculescu VE, Kinzler KW. An integrated genomic analysis of human glioblastoma multiforme. Science. 2008;321:1807–1812.
29. Sano M, Fukuda K. Activation of mitochondrial biogenesis by hormesis.
Circ Res. 2008;103:1191–1193.
30. Tortora V, Quijano C, Freeman B, Radi R, Castro L. Mitochondrial
aconitase reaction with nitric oxide, S-nitrosoglutathione, and peroxynitrite: mechanisms and relative contributions to aconitase inactivation. Free Radic Biol Med. 2007;42:1075–1088.
31. Yan LJ, Levine RL, Sohal RS. Oxidative damage during aging targets
mitochondrial aconitase. Proc Natl Acad Sci U S A. 1997;94:
11168 –11172.
32. Bulteau AL, Ikeda-Saito M, Szweda LI. Redox-dependent modulation of
aconitase activity in intact mitochondria. Biochemistry. 2003;42:
14846 –14855.
33. Bulteau AL, Lundberg KC, Ikeda-Saito M, Isaya G, Szweda LI.
Reversible redox-dependent modulation of mitochondrial aconitase and
proteolytic activity during in vivo cardiac ischemia/reperfusion. Proc Natl
Acad Sci U S A. 2005;102:5987–5991.
34. Stoessel A, Paliege A, Theilig F, Addabbo F, Ratliff B, Waschke J,
Patschan D, Goligorsky MS, Bachmann S. Indolent course of tubulointerstitial disease in a mouse model of subpressor, low-dose nitric oxide
synthase inhibition. Am J Physiol Renal Physiol. 2008;295:F717–F725.
35. Warburg O. On the origin of cancer cells. Science. 1956;123:309 –314.
36. Ott M, Zhivotovsky B, Orrenius S. Role of cardiolipin in cytochrome c
release from mitochondria. Cell Death Differ. 2007;14:1243–1247.
37. Robey RB, Hay N. Mitochondrial hexokinases, novel mediators of the
antiapoptotic effects of growth factors and Akt. Oncogene. 2006;25:
4683– 4696.
38. Majewski N, Nogueira V, Robey RB, Hay N. Akt inhibits apoptosis
downstream of BID cleavage via a glucose-dependent mechanism
involving mitochondrial hexokinases. Mol Cell Biol. 2004;24:730 –740.
39. Donati A, Cavallini G, Paradiso C, Vittorini S, Pollera M, Gori Z,
Bergamini E. Age-related changes in the autophagic proteolysis of rat
isolated liver cells: effects of antiaging dietary restrictions. J Gerontol A
Biol Sci Med Sci. 2001;56:B375–B383.
40. Baehrecke EH. Autophagy: dual roles in life and death? Nat Rev Mol Cell
Biol. 2005;6:505–510.
41. Codogno P, Meijer AJ. Autophagy and signaling: their role in cell
survival and cell death. Cell Death Differ. 2005;12(suppl 2):1509 –1518.
Mitochondria and ROS
7
42. Lemasters JJ. Selective mitochondrial autophagy, or mitophagy, as a
targeted defense against oxidative stress, mitochondrial dysfunction, and
aging. Rejuvenation Res. 2005;8:3–5.
43. Kiffin R, Bandyopadhyay U, Cuervo AM. Oxidative stress and
autophagy. Antioxid Redox Signal. 2006;8:152–162.
44. Lemasters JJ, Nieminen AL, Qian T, Trost LC, Elmore SP, Nishimura Y,
Crowe RA, Cascio WE, Bradham CA, Brenner DA, Herman B. The
mitochondrial permeability transition in cell death: a common mechanism
in necrosis, apoptosis and autophagy. Biochim Biophys Acta. 1998;1366:
177–196.
45. Chen Y, McMillan-Ward E, Kong J, Israels SJ, Gibson SB. Mitochondrial
electron-transport-chain inhibitors of complexes I and II induce autophagic cell death mediated by reactive oxygen species. J Cell Sci. 2007;
120:4155– 4166.
46. Kessel D, Reiners JJ Jr. Apoptosis and autophagy after mitochondrial or
endoplasmic reticulum photodamage. Photochem Photobiol. 2007;83:
1024 –1028.
47. Sasnauskiene A, Kadziauskas J, Vezelyte N, Jonusiene V, Kirveliene V.
Apoptosis, autophagy and cell cycle arrest following photodamage to
mitochondrial interior. Apoptosis. 2009;14:276 –286.
48. Gems D, Partridge L. Stress-response hormesis and aging: “that which
does not kill us makes us stronger.” Cell Metab. 2008;7:200 –203.
49. Motohashi H, Yamamoto M. Nrf2-Keap1 defines a physiologically
important stress response mechanism. Trends Mol Med. 2004;10:
549 –557.
50. Piantadosi CA, Suliman HB. Mitochondrial transcription factor A
induction by redox activation of nuclear respiratory factor 1. J Biol Chem.
2006;281:324 –333.
51. Wu Z, Puigserver P, Andersson U, Zhang C, Adelmant G, Mootha V,
Troy A, Cinti S, Lowell B, Scarpulla RC, Spiegelman BM. Mechanisms
controlling mitochondrial biogenesis and respiration through the thermogenic coactivator PGC-1. Cell. 1999;98:115–124.
52. Gleyzer N, Vercauteren K, Scarpulla RC. Control of mitochondrial transcription specificity factors (TFB1M and TFB2M) by nuclear respiratory
factors (NRF-1 and NRF-2) and PGC-1 family coactivators. Mol Cell
Biol. 2005;25:1354 –1366.
53. Fu X, Wan S, Lyu YL, Liu LF, Qi H. Etoposide induces ATM-dependent
mitochondrial biogenesis through AMPK activation. PLoS ONE. 2008;3:
e2009.
54. Hsu PP, Sabatini DM. Cancer cell metabolism: Warburg and beyond.
Cell. 2008;134:703–707.
55. Coloff JL, Rathmell JC. Metabolic regulation of Akt: roles reversed.
J Cell Biol. 2006;175:845– 847.
56. Denko NC. Hypoxia, HIF1 and glucose metabolism in the solid tumour.
Nat Rev Cancer. 2008;8:705–713.
57. Matoba S, Kang JG, Patino WD, Wragg A, Boehm M, Gavrilova O,
Hurley PJ, Bunz F, Hwang PM. p53 regulates mitochondrial respiration.
Science. 2006;312:1650 –1653.
58. Yeung SJ, Pan J, Lee MH. Roles of p53, MYC and HIF-1 in regulating
glycolysis-the seventh hallmark of cancer. Cell Mol Life Sci. 2008;65:
3981–3999.
59. Scatena R, Bottoni P, Pontoglio A, Mastrototaro L, Giardina B. Glycolytic enzyme inhibitors in cancer treatment. Expert Opin Investig
Drugs. 2008;17:1533–1545.
60. O’Riordan E, Mendelev N, Patschan S, Patschan D, Eskander J,
Cohen-Gould L, Chander P, Goligorsky MS. Chronic NOS inhibition
actuates endothelial-mesenchymal transformation. Am J Physiol Heart
Circ Physiol. 2007;292:H285–H294.
61. Buzzai M, Jones RG, Amaravadi RK, Lum JJ, DeBerardinis RJ, Zhao F,
Viollet B, Thompson CB. Systemic treatment with the antidiabetic drug
metformin selectively impairs p53-deficient tumor cell growth. Cancer
Res. 2007;67:6745– 6752.
62. Thorpe SR, Baynes JW. Role of the Maillard reaction in diabetes mellitus
and diseases of aging. Drugs Aging. 1996;9:69 –77.
63. Touyz RM. Reactive oxygen species in vascular biology: role in arterial
hypertension. Expert Rev Cardiovasc Ther. 2003;1:91–106.
64. Tain YL, Baylis C. Dissecting the causes of oxidative stress in an in vivo
model of hypertension. Hypertension. 2006;48:828 – 829.
65. Nakagawa T, Sato W, Glushakova O, Heinig M, Clarke T, CampbellThompson M, Yuzawa Y, Atkinson MA, Johnson RJ, Croker B. Diabetic
endothelial nitric oxide synthase knockout mice develop advanced
diabetic nephropathy. J Am Soc Nephrol. 2007;18:539 –550.
66. Sasso FC, Torella D, Carbonara O, Ellison GM, Torella M, Scardone M,
Marra C, Nasti R, Marfella R, Cozzolino D, Indolfi C, Cotrufo M, Torella
R, Salvatore T. Increased vascular endothelial growth factor expression
8
67.
68.
69.
70.
71.
72.
Downloaded from http://hyper.ahajournals.org/ by guest on June 17, 2017
73.
74.
75.
76.
77.
78.
79.
80.
81.
82.
Hypertension
June 2009
but impaired vascular endothelial growth factor receptor signaling in the
myocardium of type 2 diabetic patients with chronic coronary heart
disease. J Am Coll Cardiol. 2005;46:827– 834.
Salvemini D, Wang ZQ, Zweier JL, Samouilov A, Macarthur H, Misko
TP, Currie MG, Cuzzocrea S, Sikorski JA, Riley DP. A nonpeptidyl
mimic of superoxide dismutase with therapeutic activity in rats. Science.
1999;286:304 –306.
Giardino I, Edelstein D, Brownlee M. BCL-2 expression or antioxidants
prevent hyperglycemia-induced formation of intracellular advanced glycation endproducts in bovine endothelial cells. J Clin Invest. 1996;97:
1422–1428.
Nishikawa T, Edelstein D, Du XL, Yamagishi S, Matsumura T, Kaneda
Y, Yorek MA, Beebe D, Oates PJ, Hammes HP, Giardino I, Brownlee M.
Normalizing mitochondrial superoxide production blocks three pathways
of hyperglycaemic damage. Nature. 2000;404:787–790.
Lowell BB, Shulman GI. Mitochondrial dysfunction and type 2 diabetes.
Science. 2005;307:384 –387.
Giardina TM, Steer JH, Lo SZ, Joyce DA. Uncoupling protein-2 accumulates rapidly in the inner mitochondrial membrane during mitochondrial reactive oxygen stress in macrophages. Biochim Biophys Acta.
2008;1777:118 –129.
Chan CB, De Leo D, Joseph JW, McQuaid TS, Ha XF, Xu F, Tsushima
RG, Pennefather PS, Salapatek AM, Wheeler MB. Increased uncoupling
protein-2 levels in beta-cells are associated with impaired glucosestimulated insulin secretion: mechanism of action. Diabetes. 2001;50:
1302–1310.
Zhang CY, Baffy G, Perret P, Krauss S, Peroni O, Grujic D, Hagen T,
Vidal-Puig AJ, Boss O, Kim YB, Zheng XX, Wheeler MB, Shulman GI,
Chan CB, Lowell BB. Uncoupling protein-2 negatively regulates insulin
secretion and is a major link between obesity, beta cell dysfunction, and
type 2 diabetes. Cell. 2001;105:745–755.
Krauss S, Zhang CY, Scorrano L, Dalgaard LT, St-Pierre J, Grey ST,
Lowell BB. Superoxide-mediated activation of uncoupling protein 2
causes pancreatic beta cell dysfunction. J Clin Invest. 2003;112:
1831–1842.
Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J,
Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden
R, Young IG. Sequence and organization of the human mitochondrial
genome. Nature. 1981;290:457–465.
Simon DK, Lin MT, Ahn CH, Liu GJ, Gibson GE, Beal MF, Johns DR.
Low mutational burden of individual acquired mitochondrial DNA
mutations in brain. Genomics. 2001;73:113–116.
Stewart JD, Hudson G, Yu-Wai-Man P, Blakeley EL, He L, Horvath R,
Maddison P, Wright A, Griffiths PG, Turnbull DM, Taylor RW, Chinnery
PF. OPA1 in multiple mitochondrial DNA deletion disorders. Neurology.
2008;71:1829 –1831.
Corral-Debrinski M, Horton T, Lott MT, Shoffner JM, Beal MF, Wallace
DC. Mitochondrial DNA deletions in human brain: regional variability
and increase with advanced age. Nat Genet. 1992;2:324 –329.
Zhang J, Asin-Cayuela J, Fish J, Michikawa Y, Bonafe M, Olivieri F,
Passarino G, De Benedictis G, Franceschi C, Attardi G. Strikingly higher
frequency in centenarians and twins of mtDNA mutation causing
remodeling of replication origin in leukocytes. Proc Natl Acad Sci U S A.
2003;100:1116 –1121.
Trifunovic A. Mitochondrial DNA and ageing. Biochim Biophys Acta.
2006;1757:611– 617.
Trifunovic A, Wredenberg A, Falkenberg M, Spelbrink JN, Rovio AT,
Bruder CE, Bohlooly YM, Gidlof S, Oldfors A, Wibom R, Tornell J,
Jacobs HT, Larsson NG. Premature ageing in mice expressing defective
mitochondrial DNA polymerase. Nature. 2004;429:417– 423.
Kujoth GC, Hiona A, Pugh TD, Someya S, Panzer K, Wohlgemuth SE,
Hofer T, Seo AY, Sullivan R, Jobling WA, Morrow JD, Van Remmen H,
83.
84.
85.
86.
87.
88.
89.
90.
91.
92.
93.
94.
95.
96.
97.
98.
Sedivy JM, Yamasoba T, Tanokura M, Weindruch R, Leeuwenburgh C,
Prolla TA. Mitochondrial DNA mutations, oxidative stress, and apoptosis
in mammalian aging. Science. 2005;309:481– 484.
Ruan H, Tang XD, Chen ML, Joiner ML, Sun G, Brot N, Weissbach H,
Heinemann SH, Iverson L, Wu CF, Hoshi T. High-quality life extension
by the enzyme peptide methionine sulfoxide reductase. Proc Natl Acad
Sci U S A. 2002;99:2748 –2753.
Schriner SE, Linford NJ, Martin GM, Treuting P, Ogburn CE, Emond M,
Coskun PE, Ladiges W, Wolf N, Van Remmen H, Wallace DC, Rabinovitch
PS. Extension of murine life span by overexpression of catalase targeted to
mitochondria. Science. 2005;308:1909–1911.
de Cavanagh EM, Inserra F, Ferder M, Ferder L. From mitochondria to
disease: role of the renin-angiotensin system. Am J Nephrol. 2007;27:
545–553.
Thomas SR, Witting PK, Drummond GR. Redox control of endothelial
function and dysfunction: molecular mechanisms and therapeutic opportunities. Antioxid Redox Signal. 2008;10:1713–1765.
Zimmerman MC, Zucker IH. Mitochondrial dysfunction and
mitochondrial-produced reactive oxygen species: new targets for neurogenic hypertension? Hypertension. 2009;53:112–114.
Chan SH, Wu KL, Chang AY, Tai MH, Chan JY. Oxidative impairment
of mitochondrial electron transport chain complexes in rostral ventrolateral medulla contributes to neurogenic hypertension. Hypertension.
2009;53:217–227.
Doughan AK, Harrison DG, Dikalov SI. Molecular mechanisms of angiotensin II-mediated mitochondrial dysfunction: linking mitochondrial
oxidative damage and vascular endothelial dysfunction. Circ Res. 2008;
102:488 – 496.
Benigni A, Corna D, Zoja C, Sonzogni A, Latini R, Salio M, Conti S,
Rottoli D, Longaretti L, Cassis P, Morigi M, Coffman TM, Remuzzi G.
Disruption of the Ang II type 1 receptor promotes longevity in mice.
J Clin Invest. 2009;119:524 –530.
Toogood PL. Mitochondrial drugs. Curr Opin Chem Biol. 2008;12:
457– 463.
Smith RA, Kelso GF, Blaikie FH, Porteous CM, Ledgerwood EC, Hughes
G, James AM, Ross MF, Asin-Cayuela J, Cocheme HM, Filipovska A,
Murphy MP. Using mitochondria-targeted molecules to study mitochondrial radical production and its consequences. Biochem Soc Trans.
2003;31(pt 6):1295–1299.
Liu J, Atamna H, Kuratsune H, Ames BN. Delaying brain mitochondrial
decay and aging with mitochondrial antioxidants and metabolites. Ann
N Y Acad Sci. 2002;959:133–166.
Lehman JJ, Barger PM, Kovacs A, Saffitz JE, Medeiros DM, Kelly DP.
Peroxisome proliferator-activated receptor gamma coactivator-1
promotes cardiac mitochondrial biogenesis. J Clin Invest. 2000;106:
847– 856.
Schwartz DR, Sack MN. Targeting the mitochondria to augment myocardial protection. Curr Opin Pharmacol. 2008;8:160 –165.
Lagouge M, Argmann C, Gerhart-Hines Z, Meziane H, Lerin C, Daussin
F, Messadeq N, Milne J, Lambert P, Elliott P, Geny B, Laakso M,
Puigserver P, Auwerx J. Resveratrol improves mitochondrial function and
protects against metabolic disease by activating SIRT1 and PGC-1alpha.
Cell. 2006;127:1109 –1122.
Shiva S, Sack MN, Greer JJ, Duranski M, Ringwood LA, Burwell L,
Wang X, MacArthur PH, Shoja A, Raghavachari N, Calvert JW, Brookes
PS, Lefer DJ, Gladwin MT. Nitrite augments tolerance to ischemia/
reperfusion injury via the modulation of mitochondrial electron transfer.
J Exp Med. 2007;204:2089 –2102.
Gladwin MT, Schechter AN, Kim-Shapiro DB, Patel RP, Hogg N, Shiva
S, Cannon RO III, Kelm M, Wink DA, Espey MG, Oldfield EH, Pluta
RM, Freeman BA, Lancaster JR Jr, Feelisch M, Lundberg JO. The
emerging biology of the nitrite anion. Nat Chem Biol. 2005;1:308 –314.
Mitochondria and Reactive Oxygen Species
Francesco Addabbo, Monica Montagnani and Michael S. Goligorsky
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