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Antibiotics and the Mitochondria
Marlene E. Kunold:
Antibiotics, Marching on the Path of human Extinction
http://www.lyme-borreliose-hamburg.de/press/MEK-Antibiotics.pdf
Antibacterial drugs and their interference with the biogenesis of mitochondria
in animal and human cells
http://www.ummafrapp.de/skandal/felix/antibiotics/antibacterial_drugs.pdf
The biogenesis of mitochondria, VI. Biochemical basis of the resistance of
Saccharomyces cerevisiae toward antibiotics which specifically inhibit
mitochondrial protein synthesis.
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=224865&blobtype=pdf
Biogenesis of mitochondria. XI. A comparison of the effects of growth-limiting
oxygen
tension, intercalating agents, and antibiotics on the obligate aerobe Candida
parapsilosis.
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2107676&blobtype=pdf
Biogenesis of Mitochondria: Analysis of Deletion of Mitochondrial Antibiotic
Resistance Markers in Petite Mutants of Saccharomyces cerevisiae.
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=235632&blobtype=pdf
Influence on Mitochondria and Cytotoxicity of Different Antibiotics
Administered in High Concentrations on Primary Human Osteoblasts and Cell
Lines
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1797653&blobtype=pdf
Structural basis for selectivity and toxicity of ribosomal antibiotics
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1083859&blobtype=pdf
Familial streptomycin ototoxicity in a South African Family: A mitochondrial
disorder
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1051117&blobtype=pdf
The Renal Mitochondrial Toxicity of Beta-Lactam Antibiotics: In Vitro Effects of
Cephaloglycin and Imipenem
http://jasn.asnjournals.org/cgi/reprint/1/5/815
Cephaloridine Induces Translocation of Protein Kinase C δInto Mitochondria
and Enhances Mitochondrial Generation of Free Radicals in the Kidney Cortex
of Rats Causing Renal Dysfunction
http://www.jstage.jst.go.jp/article/jphs/98/1/49/_pdf
Mitochondrial DNA Deletions and Chloramphenicol Treatment Stimulate
the Autophagic Transcript ATG12
http://www.landesbioscience.com/journals/autophagy/article/prigioneAUTO3-4.pdf
Chloramphenicol-induced Mitochondrial Stress Increases p21 Expression and
Prevents Cell Apoptosis through a p21-dependent Pathway*
http://www.jbc.org/cgi/reprint/280/28/26193
Inhibition of mammalian mitochondrial protein synthesis by Oxazolidinones
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1479116&blobtype=pdf
Ciprofloxacin does not inhibit mitochondrial functions but other antibiotics do
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=171543&blobtype=pdf
In vitro and in vivo immunomodulatory effects of anti-Pneumocystis carinii
drugs.
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=163313&blobtype=pdf
The Sensitivity of Rat Liver and Yeast Mitochondrial Ribosomes to inhibitors of
protein synthesis
http://www.jbc.org/cgi/reprint/249/21/6806
Antimicrob Agents Chemother. 2006 Jun;50(6):2042-9.
Inhibition of mammalian mitochondrial
protein synthesis by oxazolidinones.
McKee EE, Ferguson M, Bentley AT, Marks TA.
Source
Indiana University School of Medicine--South Bend, IN 46617, USA. [email protected]
Abstract
The effects of a variety of oxazolidinones, with different antibacterial potencies, including
linezolid, on mitochondrial protein synthesis were determined in intact mitochondria isolated
from rat heart and liver and rabbit heart and bone marrow. The results demonstrate that a
general feature of the oxazolidinone class of antibiotics is the inhibition of mammalian
mitochondrial protein synthesis. Inhibition was similar in mitochondria from all tissues
studied. Further, oxazolidinones that were very potent as antibiotics were uniformly potent in
inhibiting mitochondrial protein synthesis. These results were compared to the inhibitory
profiles of other antibiotics that function by inhibiting bacterial protein synthesis. Of these,
chloramphenicol and tetracycline were significant inhibitors of mammalian mitochondrial
protein synthesis while the macrolides, lincosamides, and aminoglycosides were not.
Development of future antibiotics from the oxazolidinone class will have to evaluate potential
mitochondrial toxicity.
Supplemental Content
Toxicol Sci. 2010 Jul;116(1):140-50. Epub 2010 Mar 25.
Chloramphenicol causes mitochondrial
stress, decreases ATP biosynthesis, induces
matrix metalloproteinase-13 expression,
and solid-tumor cell invasion.
Li CH, Cheng YW, Liao PL, Yang YT, Kang JJ.
Source
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Abstract
Overuse and abuse of antibiotics can increase the risk of cancer. Chloramphenicol can inhibit
both bacterial and mitochondrial protein synthesis, causing mitochondrial stress and decreased
ATP biosynthesis. Chloramphenicol can accelerate cancer progression; however, the
underlying mechanisms of chloramphenicol in carcinogenesis and cancer progression are still
unclear. We found that chloramphenicol can induce matrix metalloproteinase (MMP)-13
expression and increase MMP-13 protein in conditioned medium, resulting in an increase in
cancer cell invasion. Chloramphenicol also activated c-Jun N-terminal kinases (JNK) and
phosphatidylinositol 3-kinase (PI-3K)/Akt signaling, leading to c-Jun protein
phosphorylation. The activated c-Jun protein has been proven to activate binding to the MMP13 promoter and also upregulate the amount of MMP-13. Both the SP 600125 (JNK inhibitor)
and LY 294002 (PI-3K/Akt inhibitor) can inhibit chloramphenicol-induced c-Jun
phosphorylation, MMP-13 expression, and cell invasion. Overexpression of the dominantnegative JNK and PI-3K p85 subunit also negate chloramphenicol-induced responses. Other
antibiotics that cause mitochondrial stress and a decrease in ATP biosynthesis also induce
MMP-13 expression. These findings suggest that chloramphenicol-induced PI-3K/Akt, JNK
phosphorylation, and activator protein 1 activation might function as a novel mitochondrial
stress signal that result in an increase of MMP-13 expression and MMP-13-associated cancer
cell invasion. The findings of this study confirms that chloramphenicol, and other 70S
ribosomal inhibitors, should be administered with caution, especially during cancer therapy.
Supplemental Content
Antimicrob Agents Chemother. 1998 Aug;42(8):1923-30.
Ciprofloxacin induces an
immunomodulatory stress response in
human T lymphocytes.
Riesbeck K, Forsgren A, Henriksson A, Bredberg A.
Source
Department of Medical Microbiology, Lund University, Malmö University Hospital, S-205 02
Malmö, Sweden. [email protected]
Abstract
Exposure of cells to adverse environmental conditions invokes a genetically programmed
series of events resulting in the induction of specific genes. The fluoroquinolone antibiotic
ciprofloxacin has recently been reported to upregulate interleukin-2 (IL-2) gene induction. In
the present investigation, the effect of ciprofloxacin at supratherapeutic concentrations on
immediate-early (<2 h) gene expression in primary human peripheral blood lymphocytes was
studied with Northern blots. In addition, transcriptional activity of IL-2 and metallothionein
enhancer and promoter regions and transcription factors AP-1, NF-kappaB, and NF-AT were
analyzed by chloramphenicol acetyltransferase (CAT) and electrophoretic mobility shift
assays, respectively. The concentration of c-fos, c-jun, c-myc, junB, and fra-1 mRNAs was
increased in activated peripheral blood lymphocytes incubated with ciprofloxacin compared
to that in untreated controls. Ciprofloxacin increased CAT activity in stimulated lymphocytes
transfected with plasmids containing either the IL-2 or metallothionein enhancer.
Furthermore, among the transcription factors tested, AP-1 activity was increased in stimulated
purified T helper lymphocytes incubated with ciprofloxacin compared to drug-free controls.
Taken together, ciprofloxacin increased the levels of immediate-early transcripts, enhanced
IL-2 and metallothionein promoter induction, and upregulated AP-1 concentrations in primary
lymphocytes, reflecting a program commonly observed in mammalian stress responses.
Supplemental Content
Antimicrob Agents Chemother. 1990 Jan;34(1):167-9.
Ciprofloxacin does not inhibit
mitochondrial functions but other
antibiotics do.
Riesbeck K, Bredberg A, Forsgren A.
Source
Department of Medical Microbiology, University of Lund, Malmö General Hospital, Sweden.
Abstract
At clinical concentrations, ciprofloxacin did not inhibit mitochondrial DNA replication,
oxidative phosphorylation, protein synthesis, or mitochondrial mass (transmembrane
potential). No difference in supercoiled forms of DNA was observed. The tetracyclines and
chloramphenicol inhibited protein synthesis at clinically achievable concentrations, while
rifampin, fusidic acid, and clindamycin did not.
Supplemental Content
Chem Biol Interact. 2008 Jun 17;173(3):187-94. Epub 2008 Mar 21.
Interaction of beta-lactam antibiotics with
the mitochondrial carnitine/acylcarnitine
transporter.
Pochini L, Galluccio M, Scumaci D, Giangregorio N, Tonazzi A, Palmieri F, Indiveri C.
Source
Department of Cell Biology, University of Calabria, Via P.Bucci 4c, 87036 Arcavacata di
Rende, Italy.
Abstract
The interaction of beta-lactams with the purified mitochondrial carnitine/acylcarnitine
transporter reconstituted in liposomes has been studied. Cefonicid, cefazolin, cephalothin,
ampicillin, piperacillin externally added to the proteoliposomes, inhibited the
carnitine/carnitine antiport catalysed by the reconstituted transporter. The most effective
inhibitors were cefonicid and ampicillin with IC50 of 6.8 and 7.6mM, respectively. The other
inhibitors exhibited IC50 values above 36 mM. Kinetic analysis performed with cefonicid and
ampicillin revealed that the inhibition is completely competitive, i.e., the inhibitors interact
with the substrate binding site. The Ki of the transporter is 4.9 mM for cefonicid and 9.9 mM
for ampicillin. Cefonicid inhibited the transporter also on its internal side. The IC50 was 12.9
mM indicating that the inhibition was less pronounced than on the external side. Ampicillin
and the other inhibitors were much less effective on the internal side. The beta-lactams were
not transported by the carnitine/acylcarnitine transporter. Cephalosporins, and at much lower
extent penicillins, caused irreversible inhibition of the transporter after prolonged time of
incubation. The most effective among the tested antibiotics was cefonicid with IC50 of 0.12
mM after 60 h of incubation. The possible in vivo implications of the interaction of the betalactam antibiotics with the transporter are discussed.
Supplemental Content
Antimicrob Agents Chemother. 2005 Sep;49(9):3896-902.
Oxazolidinones inhibit cellular proliferation
via inhibition of mitochondrial protein
synthesis.
Nagiec EE, Wu L, Swaney SM, Chosay JG, Ross DE, Brieland JK, Leach KL.
Source
Department of Antibacterial Pharmacology, Pfizer, Ann Arbor, MI 48105, USA.
Abstract
The oxazolidinones are a relatively new structural class of antibacterial agents that act by
inhibiting bacterial protein synthesis. The oxazolidinones inhibit mitochondrial protein
synthesis, as shown by [35S]methionine incorporation into intact rat heart mitochondria.
Treatment of K562 human erythroleukemia cells with the oxazolidinone eperezolid resulted in
a time- and concentration-dependent inhibition of cell proliferation. The cells remained
viable, but an increase in doubling time was observed with eperezolid treatment. Inhibition
was reversible, since washing and refeeding of cells in the absence of compound resulted in a
resumption of growth. The growth-inhibitory effect of the oxazolidinones did not appear to be
cell type specific, and inhibition of CHO and HEK cells also was demonstrated. Treatment of
cells resulted in a decrease in mitochondrial cytochrome oxidase subunit I levels, consistent
with an inhibition of mitochondrial protein synthesis. Eperezolid caused no growth inhibition
of rho zero (rho0) cells, which contain no mitochondrial DNA; however, the growth of the
parent 143B cells was inhibited. These results provide a direct demonstration that the
inhibitory effect of eperezolid in mammalian cells is the result of mitochondrial protein
synthesis inhibition.
Supplemental Content
Antimicrob Agents Chemother. 2007 Jan;51(1):54-63. Epub 2006 Nov 6.
Influence on mitochondria and cytotoxicity
of different antibiotics administered in high
concentrations on primary human
osteoblasts and cell lines.
Duewelhenke N, Krut O, Eysel P.
Source
Klinik und Poliklinik für Orthopädie, Universitätsklinikum Köln, Joseph-Stelzmann-Str. 24,
50931 Köln, Germany. [email protected]
Abstract
Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still
represent the worst complications of orthopedic surgery and traumatology. Successful
treatment requires, besides surgical débridement, long-term systemic and high-concentration
local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and
more. In this study, we investigated the effect of 20 different antibiotics on primary human
osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High
concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin,
tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic
activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not.
Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to
40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for
chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The
proliferation of the cell lines was always less inhibited. We established the measurement of
extracellular lactate concentration as an indicator of glycolysis using inhibitors of the
respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid)
as reference compounds, whereas inhibition of the respiratory chain increased and inhibition
of glycolysis decreased lactate production. The measurement of extracellular lactate
concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline,
and especially chloramphenicol and linezolid impaired mitochondrial energetics in high
concentrations. This explains partly the observed inhibition of metabolic activity and
proliferation in our experiments. Because of differences in the energy metabolism, PHO
provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
Supplemental Content
Biochem Pharmacol. 2009 Mar 1;77(5):888-96. Epub 2008 Nov 12.
Inhibitory modulation of the mitochondrial
permeability transition by minocycline.
Gieseler A, Schultze AT, Kupsch K, Haroon MF, Wolf G, Siemen D, Kreutzmann P.
Source
Institute of Medical Neurobiology, Otto-von-Guericke University Magdeburg, Leipziger Str.
44, D-39120 Magdeburg, Germany.
Abstract
The semi-synthetic tetracycline derivative minocycline exerts neuroprotective properties in
various animal models of neurodegenerative disorders. Although anti-inflammatory and antiapoptotic effects are reported to contribute to the neuroprotective action, the exact molecular
mechanisms underlying the beneficial properties of minocycline remain to be clarified. We
analyzed the effects of minocycline in a cell culture model of neuronal damage and in singlechannel measurements on isolated mitoplasts. Treatment of neuron-enriched cortical cultures
with rotenone, a high affinity inhibitor of the mitochondrial complex I, resulted in a
deregulation of the intracellular Ca2+-dynamics, as recorded by live cell imaging.
Minocycline (100 microM) and cyclosporin A (2 microM), a known inhibitor of the
mitochondrial permeability transition pore, decreased the rotenone-induced Ca2+deregulation by 60.9% and 37.6%, respectively. Investigations of the mitochondrial
permeability transition pore by patch-clamp techniques revealed for the first time a dosedependent reduction of the open probability by minocycline (IC(50)=190 nM). Additionally,
we provide evidence for the high antioxidant potential of MC in our model. In conclusion, the
present data substantiate the beneficial properties of minocycline as promising
neuroprotectant by its inhibitory activity on the mitochondrial permeability transition pore.
Supplemental Content
Biochem Biophys Res Commun. 2008 Apr 11;368(3):631-6. Epub 2008 Feb 7.
A mutation in mitochondrial 12S rRNA,
A827G, in Argentinean family with hearing
loss after aminoglycoside treatment.
Chaig MR, Zernotti ME, Soria NW, Romero OF, Romero MF, Gerez NM.
Source
Cátedra de Bioquímica y Biología molecular, FCM-UNC, Haya de la Torre, S/N Ciudad
Universitaria, 2do, Piso, Pabellón CP 5016, Argentina.
Abstract
Mutations in mitochondrial DNA (mtDNA) have been found to be associated with
sensorineural hearing loss. We report the clinical, genetic, and molecular characterization of
one Argentinean family with aminoglycoside-induced impairment in two of their members.
Clinical evaluation revealed the variable phenotype of hearing impairment including
audiometric configuration in these subjects. Mutational analysis of the mtDNA in these
pedigrees showed the presence of homoplasmic 12S rRNA A827G mutation, which has been
associated with hearing impairment. The A827G mutation is located at the A-site of the
mitochondrial 12S rRNA gene which is highly conserved in mammals. It is possible that the
alteration of the tertiary or quaternary structure of this rRNA by the A827G mutation may
lead to mitochondrial dysfunction, thereby playing a role in the pathogenesis of hearing loss
and aminoglycoside hypersensitivity. However, incomplete penetrance of hearing impairment
indicates that the A827G mutation itself is not sufficient to produce clinical phenotype.
Supplemental Content
Proc Natl Acad Sci U S A. 2008 Dec 30;105(52):20888-93. Epub 2008 Dec 22.
Genetic analysis of interactions with
eukaryotic rRNA identify the mitoribosome
as target in aminoglycoside ototoxicity.
Hobbie SN, Akshay S, Kalapala SK, Bruell CM, Shcherbakov D, Böttger EC.
Source
Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 32, CH-8006
Zurich, Switzerland.
Abstract
Aminoglycoside ototoxicity has been related to a surprisingly large number of cellular
structures and metabolic pathways. The finding that patients with mutations in mitochondrial
rRNA are hypersusceptible to aminoglycoside-induced hearing loss has indicated a possible
role for mitochondrial protein synthesis. To study the molecular interaction of
aminoglycosides with eukaryotic ribosomes, we made use of the observation that the drug
binding site is a distinct domain defined by the small subunit rRNA, and investigated drug
susceptibility of bacterial hybrid ribosomes carrying various alleles of the eukaryotic
decoding site. Compared to hybrid ribosomes with the A site of human cytosolic ribosomes,
susceptibility of mitochondrial hybrid ribosomes to various aminoglycosides correlated with
the relative cochleotoxicity of these drugs. Sequence alterations that correspond to the
mitochondrial deafness mutations A1555G and C1494T increased drug-binding and rendered
the ribosomal decoding site hypersusceptible to aminoglycoside-induced mistranslation and
inhibition of protein synthesis. Our results provide experimental support for aminoglycosideinduced dysfunction of the mitochondrial ribosome. We propose a pathogenic mechanism in
which interference of aminoglycosides with mitochondrial protein synthesis exacerbates the
drugs' cochlear toxicity, playing a key role in sporadic dose-dependent and genetically
inherited, aminoglycoside-induced deafness.
Supplemental Content
J Med Genet. 1997 Nov;34(11):904-6.
Familial streptomycin ototoxicity in a South
African family: a mitochondrial disorder.
Gardner JC, Goliath R, Viljoen D, Sellars S, Cortopassi G, Hutchin T, Greenberg J, Beighton
P.
Source
Department of Human Genetics, University of Cape Town Medical School, Observatory,
South Africa.
Abstract
The vestibular and ototoxic effects of the aminoglycoside antibiotics (streptomycin,
gentamycin, kanamycin, tobramycin, neomycin) are well known; streptomycin, in particular,
has been found to cause irreversible, profound, high frequency sensorineural deafness in
hypersensitive persons. Aminoglycoside ototoxicity occurs both sporadically and within
families and has been associated with a mitochondrial DNA (mtDNA) 1555A to G point
mutation in the 12S ribosomal RNA gene. We report on the molecular analysis of a South
African family with streptomycin induced sensorineural deafness in which we have found
transmission of this same predisposing mutation. It is now possible to identify people who are
at risk of hearing loss if treated with aminoglycosides in the future and to counsel them
accordingly. In view of the fact that aminoglycoside antibiotics remain in widespread use for
the treatment of infections, in particular for tuberculosis, which is currently of epidemic
proportions in South Africa, this finding has important implications for the family concerned.
In addition, other South African families may potentially be at risk if they carry the same
mutation.
Supplemental Content
J Biol Chem. 2005 Jul 15;280(28):26193-9. Epub 2005 May 19.
Chloramphenicol-induced mitochondrial
stress increases p21 expression and prevents
cell apoptosis through a p21-dependent
pathway.
Li CH, Tzeng SL, Cheng YW, Kang JJ.
Source
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 100,
Taiwan.
Abstract
Pretreatment of HepG2 and H1299 cells with chloramphenicol rendered the cells resistant to
mitomycin-induced apoptosis. Both mitomycin-induced caspase 3 activity and PARP
activation were also inhibited. The mitochondrial DNA-encoded Cox I protein, but not
nuclear-encoded proteins, was down-regulated in chloramphenicol-treated cells. Cellular
levels of the p21(waf1/cip1) protein and p21(waf1/cip1) mRNA were increased through a
p53-independent pathway, possibly because of the stabilization of p21(waf1/cip1) mRNA in
chloramphenicol-treated cells. The p21(waf1/cip1) was redistributed from the perinuclear
region to the cytoplasm and co-localized with mitochondrial marker protein. Several
morphological changes and activation of the senescence-associated biomarker, SA betagalactosidase, were observed in these cells. Both p21(waf1/cip1) antisense and small
interfering RNA could restore apoptotic-associated caspase 3 activity, PARP activation, and
sensitivity to mitomycin-induced apoptosis. Similar effects were seen with other antibiotics
that inhibit mitochondrial translation, including minocycline, doxycycline, and clindamycin.
These findings suggested that mitochondrial stress causes resistance to apoptosis through a
p21-dependent pathway.
Supplemental Content
Biochem Pharmacol. 2009 Mar 1;77(5):888-96. Epub 2008 Nov 12.
Inhibitory modulation of the mitochondrial
permeability transition by minocycline.
Gieseler A, Schultze AT, Kupsch K, Haroon MF, Wolf G, Siemen D, Kreutzmann P.
Source
Institute of Medical Neurobiology, Otto-von-Guericke University Magdeburg, Leipziger Str.
44, D-39120 Magdeburg, Germany.
Abstract
The semi-synthetic tetracycline derivative minocycline exerts neuroprotective properties in
various animal models of neurodegenerative disorders. Although anti-inflammatory and antiapoptotic effects are reported to contribute to the neuroprotective action, the exact molecular
mechanisms underlying the beneficial properties of minocycline remain to be clarified. We
analyzed the effects of minocycline in a cell culture model of neuronal damage and in singlechannel measurements on isolated mitoplasts. Treatment of neuron-enriched cortical cultures
with rotenone, a high affinity inhibitor of the mitochondrial complex I, resulted in a
deregulation of the intracellular Ca2+-dynamics, as recorded by live cell imaging.
Minocycline (100 microM) and cyclosporin A (2 microM), a known inhibitor of the
mitochondrial permeability transition pore, decreased the rotenone-induced Ca2+deregulation by 60.9% and 37.6%, respectively. Investigations of the mitochondrial
permeability transition pore by patch-clamp techniques revealed for the first time a dosedependent reduction of the open probability by minocycline (IC(50)=190 nM). Additionally,
we provide evidence for the high antioxidant potential of MC in our model. In conclusion, the
present data substantiate the beneficial properties of minocycline as promising
neuroprotectant by its inhibitory activity on the mitochondrial permeability transition pore.
Supplemental Content
Tetracycline treatment influences mitochondrial
metabolism and mtDNA density two generations after
treatment in Drosophila.
Ballard JW, Melvin RG.
Ramaciotti Centre for Gene Function Analysis, School of Biotechnology and
Biomolecular Sciences, University of New South Wales, Sydney, Australia.
[email protected]
Tetracycline is commonly used to clear Wolbachia from infected insects. Studies then
compare specific biochemical and/or life-history traits between infected and
uninfected individuals with the same genetic background. We investigated the
potential for tetracycline to influence mitochondrial efficiency and mitochondrial
(mt)DNA density two generations after treatment in Drosophila simulans. We
observed that antibiotic treatment resulted in a decline in inorganic phosphate
incorporated into ATP per mole of oxygen consumed (ADP:O ratio). Further,
tetracycline treatment caused a significant increase in mtDNA density in naturally
Wolbachia-uninfected but not in naturally Wolbachia-infected lines suggesting a
dosage effect. These data suggest that the current practice of comparing Wolbachiainfected and Wolbachia-uninfected insects two generations after tetracycline treatment
needs to be re-evaluated.
Swiss Med Wkly. 2010 Sep 24;140:w13080. doi: 10.4414/smw.2010.13080.
Liver injury caused by drugs: an update.
Stirnimann G, Kessebohm K, Lauterburg B.
Source
Institut for clinical pharmacology and Visceral Research, University of Bern, Bern,
Switzerland.
Abstract
Although severe idiosyncratic drug-induced liver injury (DILI) is a rare event, it has a large
impact on the fate of affected patients and the incriminated drug. Hepatic metabolism of
drugs, which occurs in the generation of chemically reactive metabolites in critical amounts,
seems to underlie most instances of DILI. Genetic polymorphisms in activating and
detoxifying enzymes determine, in part, the extent of cellular stress. A cascade of events,
where the pathogenetic relevance of single steps is likely to vary from drug to drug, leads to
the disturbance of cellular homeostasis, to mitochondrial dysfunction, to the activation of cell
death promoting pathways and the release of drug-modified macromolecules and/or danger
signals that initiate an innate and/or adaptive immune response. The patient's response to the
initial drug-induced cellular dysfunction determines whether adaptation to the drug-induced
cellular stress or DILI in one of its many forms of clinical presentation occurs. Although risk
factors for developing DILI have been identified and many pathogenetic mechanisms have
been elucidated in model systems, idiosyncratic drug reactions remain unpredictable.
Supplemental Content
Toxicol Sci. 2011 Feb;119(2):245-56. Epub 2010 Sep 9.
An integrative overview on the mechanisms
underlying the renal tubular cytotoxicity of
gentamicin.
Quiros Y, Vicente-Vicente L, Morales AI, López-Novoa JM, López-Hernández FJ.
Source
Departamento de Fisiología y Farmacología, Universidad de Salamanca, 37007 Salamanca,
Spain.
Abstract
Gentamicin is an aminoglycoside antibiotic widely used against infections by Gram-negative
microorganisms. Nephrotoxicity is the main limitation to its therapeutic efficacy. Gentamicin
nephrotoxicity occurs in 10-20% of therapeutic regimes. A central aspect of gentamicin
nephrotoxicity is its tubular effect, which may range from a mere loss of the brush border in
epithelial cells to an overt tubular necrosis. Tubular cytotoxicity is the consequence of many
interconnected actions, triggered by drug accumulation in epithelial tubular cells.
Accumulation results from the presence of the endocytic receptor complex formed by megalin
and cubulin, which transports proteins and organic cations inside the cells. Gentamicin then
accesses and accumulates in the endosomal compartment, the Golgi and endoplasmic
reticulum (ER), causes ER stress, and unleashes the unfolded protein response. An excessive
concentration of the drug over an undetermined threshold destabilizes intracellular
membranes and the drug redistributes through the cytosol. It then acts on mitochondria to
unleash the intrinsic pathway of apoptosis. In addition, lysosomal cathepsins lose confinement
and, depending on their new cytosolic concentration, they contribute to the activation of
apoptosis or produce a massive proteolysis. However, other effects of gentamicin have also
been linked to cell death, such as phospholipidosis, oxidative stress, extracellular calciumsensing receptor stimulation, and energetic catastrophe. Besides, indirect effects of
gentamicin, such as reduced renal blood flow and inflammation, may also contribute or
amplify its cytotoxicity. The purpose of this review was to critically integrate all these effects
and discuss their relative contribution to tubular cell death.
Supplemental Content
Chem Biol Interact. 2010 Oct 6;188(1):204-13. Epub 2010 Jul 23.
Trovafloxacin, a fluoroquinolone antibiotic
with hepatotoxic potential, causes
mitochondrial peroxynitrite stress in a
mouse model of underlying mitochondrial
dysfunction.
Hsiao CJ, Younis H, Boelsterli UA.
Source
University of Connecticut, School of Pharmacy, Department of Pharmaceutical Sciences,
Storrs, CT 06269-3092, USA.
Abstract
Trovafloxacin (TVX) is a fluoroquinolone antibiotic whose therapeutic use was severely
restricted due to an unacceptable risk of idiosyncratic liver injury. Oxidative stress and
mitochondrial injury have been implicated in fluoroquinolone toxicity, but the mechanisms
underlying liver injury are poorly understood. Because TVX-induced hepatotoxicity cannot be
modeled in normal healthy rodents, we asked whether an underlying genetic defect
(heterozygous deficiency in mitochondrial superoxide dismutase, Sod2) might aggravate
TVX-induced mitochondrial adverse effects. Wild-type and Sod2(+/-) mice were treated with
vehicle or alatrofloxacin (the prodrug of TVX, 33mg/kg/day, ip) for 28 days. We found that
hepatic protein carbonyls were increased by 2.5-fold and hepatic mitochondrial aconitase
activity was decreased by 20% in mutant, but not wild-type mice. Because aconitase is a
major target of peroxynitrite, we determined the extent of nitrotyrosine residues in hepatic
mitochondrial proteins. Trovafloxacin significantly increased nitrotyrosine in Sod2(+/-) mice
only. Using the NO-selective probe DAF-2, we found that TVX increased the production of
mitochondrial NO in immortalized human hepatocytes. Similarly, mitochondrial Ca(2+) was
increased by TVX, suggesting Ca(2+)-dependent activation of mitochondrial NOS activity.
Furthermore, the transcript levels of the mtDNA-encoded gene Cox2/mtCo2 were decreased
in Sod2(+/-) mice only, while the expression of nDNA-encoded mitochondrial genes was not
significantly altered in both genotypes, suggesting selective effects on mtDNA expression.
The amount of mtDNA (copy number) was, however, unchanged. These data indicate that
TVX enhances hepatic mitochondrial peroxynitrite stress in mice with underlying increased
basal levels of superoxide, leading to the disruption of critical mitochondrial enzymes and
gene regulation.
Supplemental Content
Toxicol In Vitro. 2010 Jun;24(4):1111-8. Epub 2010 Mar 21.
The effects of antimycin A on endothelial
cells in cell death, reactive oxygen species
and GSH levels.
You BR, Park WH.
Source
Department of Physiology, Medical School, Research Institute of Clinical Medicine, Chonbuk
National University, JeonJu 561-180, Republic of Korea.
Abstract
Antimycin A (AMA) inhibits mitochondrial electron transport chain between cytochrome b
and c. Here, we evaluated the effects of AMA on the growth and death of endothelial cells
(ECs) in relation to reactive oxygen species (ROS) and glutathione (GSH) levels. AMA
inhibited the growth of calf pulmonary artery endothelial cells (CPAEC) and human umbilical
vein endothelial cells (HUVEC). AMA also induced apoptosis in both ECs which was
accompanied by the loss of mitochondrial membrane potential (MMP; DeltaPsi(m)). HUVEC
were more sensitive to AMA than CPAEC. AMA increased ROS level in CPAEC but
decreased the levels in HUVEC. Z-VAD (pan-caspase inhibitor) mildly prevented apoptosis
in AMA-treated ECs without the significant changes of ROS. N-acetyl-cysteine (NAC; a
well-known antioxidant) decreased ROS levels in AMA-treated ECs. NAC reduced CPAEC
death by AMA but enhanced HUVEC death by it. Furthermore, AMA increased GSH
depleted cell numbers in ECs. Buthionine sulfoximine (BSO; an inhibitor of GSH synthesis),
showing a pro-apoptotic effect on AMA-treated HUVEC, significantly increased GSH
depleted cell number but it did not affect cell death and GSH depletion in AMA-treated
CPAEC. In conclusion, AMA inhibited the growth of ECs via caspase-dependent apoptosis.
ROS level change by AMA was partially related to CPAEC death, but did not affect HUVEC
death. The change of GSH contents by AMA influenced the death of ECs.
Copyright 2010 Elsevier Ltd. All rights reserved.
Supplemental Content
Mitochondrion. 2010 Mar;10(2):115-24. Epub 2009 Nov 10.
Ethambutol-induced optic neuropathy
linked to OPA1 mutation and mitochondrial
toxicity.
Guillet V, Chevrollier A, Cassereau J, Letournel F, Gueguen N, Richard L, Desquiret V,
Verny C, Procaccio V, Amati-Bonneau P, Reynier P, Bonneau D.
Source
INSERM, U694, Angers, F-49000, France.
Abstract
Ethambutol (EMB), widely used in the treatment of tuberculosis, has been reported to cause
Leber's hereditary optic neuropathy in patients carrying mitochondrial DNA mutations. We
study the effect of EMB on mitochondrial metabolism in fibroblasts from controls and from a
man carrying an OPA1 mutation, in whom the drug induced the development of autosomal
dominant optic atrophy (ADOA). EMB produced a mitochondrial coupling defect together
with a 25% reduction in complex IV activity. EMB induced the formation of vacuoles
associated with decreased mitochondrial membrane potential and increased fragmentation of
the mitochondrial network. Mitochondrial genetic variations may therefore be predisposing
factors in EMB-induced ocular injury.
Supplemental Content
Nephrol Dial Transplant. 2010 Jan;25(1):69-76. Epub 2009 Sep 8.
Increased urinary losses of carnitine and
decreased intramitochondrial coenzyme A
in gentamicin-induced acute renal failure in
rats.
Al-Shabanah OA, Aleisa AM, Al-Yahya AA, Al-Rejaie SS, Bakheet SA, Fatani AG, SayedAhmed MM.
Source
Department of Pharmacology, College of Pharmacy, King Saud University, P.O. Box 2457,
Riyadh 11451, Kingdom of Saudi Arabia.
Abstract
BACKGROUND:
This study examined whether carnitine deficiency is a risk factor and should be viewed as a
mechanism during the development of gentamicin (GM)-induced ARF as well as exploring if
carnitine supplementation could offer protection against this toxicity.
METHODS:
Adult male Wistar albino rats were assigned to one of six treatment groups: group 1 (control)
rats were given daily intraperitoneal (I.P.) injections of normal saline for 8 consecutive days;
groups 2, 3 and 4 rats were given GM (80 mg/kg/day, I.P.), l-carnitine (200 mg/kg/day, I.P.)
and d-carnitine (250 mg/kg/day, I.P.), respectively, for 8 consecutive days. Rats of group 5
(GM plus d-carnitine) received a daily I.P. injection of d-carnitine (250 mg/kg/day) 1 h before
GM (80 mg/kg/day) for 8 consecutive days. Rats of group 6 (GM plus l-carnitine) received a
daily I.P. injection of l-carnitine (200 mg/kg/day) 1 h before GM (80 mg/kg/day) for 8
consecutive days.
RESULTS:
GM significantly increased serum creatinine, blood urea nitrogen (BUN), urinary carnitine
excretion, intramitochondrial acetyl-CoA and total nitrate/nitrite (NOx) and thiobarbituric
acid reactive substances (TBARS) in kidney tissues and significantly decreased total
carnitine, intramitochondrial CoA-SH, ATP, ATP/ADP and reduced glutathione (GSH) in
kidney tissues. In carnitine-depleted rats, GM caused a progressive increase in serum
creatinine, BUN and urinary carnitine excretion and a progressive decrease in total carnitine,
intamitochondrial CoA-SH and ATP. Interestingly, l-carnitine supplementation resulted in a
complete reversal of the increase in serum creatinine, BUN, urinary carnitine excretion and
the decrease in total carnitine, intramitochondrial CoA-SH and ATP, induced by GM, to the
control values. Moreover, the histopathological examination of kidney tissues confirmed the
biochemical data, where l-carnitine prevents and d-carnitine aggravates GM-induced ARF.
CONCLUSIONS:
(i) GM-induced nephrotoxicity leads to increased urinary losses of carnitine; (ii) carnitine
deficiency is a risk factor and should be viewed as a mechanism during the development of
GM-induced ARF; and (iii) carnitine supplementation ameliorates the severity of GMinduced kidney dysfunction by increasing the intramitochondrial CoA-SH/acetyl-CoA ratio
and ATP production.
Supplemental Content
J Pharmacol Sci. 2009 May;110(1):69-77. Epub 2009 Apr 29.
Rokitamycin induces a mitochondrial defect
and caspase-dependent apoptosis in human
T-cell leukemia Jurkat cells.
Fukui M, Nagahara Y, Nishio Y, Honjoh T, Shinomiya T.
Source
Department of Pharmacology, University of Kansas Medical Center, Kansas City, KS 66160,
USA.
Abstract
Macrolides are a well-known family of oral antibiotics whose antibacterial spectrum of
activity covers most relevant bacterial species responsible for respiratory infectious disease.
In recent years, it has been reported that macrolides have not only bactericidal activity but
also direct immunomodulating activity in mammals. In this study, we observed new
physiological activity of macrolides and examined whether various macrolides induce
apoptosis in human leukemia cell lines. We investigated the effects of 13 different macrolides
on the viability of Jurkat and HL-60 cells. Among all the macrolides used in this study,
rokitamycin, a semisynthetic macrolide with a 16-member ring, effectively induced cell death.
Rokitamycin induced DNA fragmentation and caspase activation, resembling the progression
of apoptosis. Moreover, rokitamycin reduced the mitochondrial transmembrane potential and
released cytochrome c from mitochondria to the cytosol, suggesting that mitochondrial
perturbation is involved in rokitamycin-induced apoptosis. These results suggest that
rokitamycin possesses not only bactericidal activity but also pro-apoptotic activity in human
leukemia cells.
Supplemental Content
Noise Health. 2009 Jan-Mar;11(42):26-32.
Synergistic ototoxicity due to noise exposure
and aminoglycoside antibiotics.
Li H, Steyger PS.
Source
Oregon Hearing Research Center, Oregon Health and Science University, Portland, Oregon,
USA.
Abstract
Acoustic exposure to high intensity and/or prolonged noise causes temporary or permanent
threshold shifts in auditory perception, reflected by reversible or irreversible damage in the
cochlea. Aminoglycoside antibiotics, used for treating or preventing life-threatening bacterial
infections, also induce cytotoxicity in the cochlea. Combined noise and aminoglycoside
exposure, particularly in neonatal intensive care units, can lead to auditory threshold shifts
greater than simple summation of the two insults. The synergistic toxicity of acoustic
exposure and aminoglycoside antibiotics is not limited to simultaneous exposures. Prior
acoustic insult which does not result in permanent threshold shifts potentiates aminoglycoside
ototoxicity. In addition, exposure to subdamaging doses of aminoglycosides aggravates noiseinduced cochlear damage. The mechanisms by which aminoglycosides cause auditory
dysfunction are still being unraveled, but likely include the following: 1) penetration into the
endolymphatic fluid of the scala media, 2) permeation of nonselective cation channels on the
apical surface of hair cells, and 3) generation of toxic reactive oxygen species and interference
with other cellular pathways. Here we discuss the effect of combined noise and
aminoglycoside exposure to identify pivotal synergistic events that can potentiate ototoxicity,
in addition to a current understanding of aminoglycoside trafficking within the cochlea.
Preventing the ototoxic synergy of noise and aminoglycosides is best achieved by using nonototoxic bactericidal drugs, and by attenuating perceived noise intensity when life-saving
aminoglycoside therapy is required.
Supplemental Content
Toxicol Sci. 2009 Jan;107(1):258-69. Epub 2008 Oct 16.
Gene expression analysis reveals new
possible mechanisms of vancomycininduced nephrotoxicity and identifies gene
markers candidates.
Dieterich C, Puey A, Lin S, Swezey R, Furimsky A, Fairchild D, Mirsalis JC, Ng HH.
Source
Biosciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, California
94025-3493, USA.
Erratum in

Toxicol Sci. 2009 Mar;108(1):222. Lyn, Sylvia [corrected to Lin, Sylvia ].
Abstract
Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus
aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular
mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of
vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip
administration. Groups of six female BALB/c mice were treated with seven daily iv or ip
doses of vancomycin (50, 200, and 400 mg/kg) or saline, and sacrificed on day 8. Clinical
chemistry and histopathology demonstrated kidney injury at 400 mg/kg only. Hierarchical
clustering analysis revealed that kidney gene expression profiles of all mice treated at 400
mg/kg clustered with those of mice administered 200 mg/kg iv. Transcriptional profiling
might thus be more sensitive than current clinical markers for detecting kidney damage,
though the profiles can differ with the route of administration. Analysis of transcripts whose
expression was changed by at least twofold compared with vehicle saline after high iv and ip
doses of vancomycin suggested the possibility of oxidative stress and mitochondrial damage
in vancomycin-induced toxicity. In addition, our data showed changes in expression of
several transcripts from the complement and inflammatory pathways. Such expression
changes were confirmed by relative real-time reverse transcription-polymerase chain reaction.
Finally, our results further substantiate the use of gene markers of kidney toxicity such as
KIM-1/Havcr1, as indicators of renal injury.
Supplemental Content
Curr Pharm Des. 2007;13(1):119-26.
Aminoglycoside-induced ototoxicity.
Selimoglu E.
Source
Inonu University, Department of Otorhinolaryngology, Malatya, Turkey.
[email protected]
Abstract
It has long been known that the major irreversible toxicity of aminoglycosides is ototoxicity.
Among them, streptomycin and gentamicin are primarily vestibulotoxic, whereas amikacin,
neomycin, dihydrosterptomycin, and kanamicin are primarily cochleotoxic. Cochlear damage
can produce permanent hearing loss, and damage to the vestibular apparatus results in
dizziness, ataxia, and/or nystagmus. Aminoglycosides appear to generate free radicals within
the inner ear, with subsequent permanent damage to sensory cells and neurons, resulting in
permanent hearing loss. Two mutations in the mitochondrial 12S ribosomal RNA gene have
been previously reported to predispose carriers to aminoglycoside-induced ototoxicity. As
aminoglycosides are indispensable agents both in the treatment of infections and Meniere's
disease, a great effort has been made to develop strategies to prevent aminoglycoside
ototoxicity. Anti-free radical agents, such as salicylate, have been shown to attenuate the
ototoxic effects of aminoglycosides. In this paper, incidence, predisposition, mechanism, and
prevention of aminoglycoside-induced ototoxicity is discussed in the light of literature data.
Supplemental Content
Antimicrob Agents Chemother. 2007 Mar;51(3):962-7. Epub 2006 Dec 28.
Reversible inhibition of mitochondrial
protein synthesis during linezolid-related
hyperlactatemia.
Garrabou G, Soriano A, López S, Guallar JP, Giralt M, Villarroya F, Martínez JA,
Casademont J, Cardellach F, Mensa J, Miró O.
Source
Mitochondrial Research Laboratory, Muscle Research Unit, Internal Medicine Department,
Hospital Clinic of Barcelona, Villarroel 170, 08036 Barcelona, Catalonia, Spain.
Abstract
The objective of the present study was to determine the mitochondrial toxicity mechanisms of
linezolid-related hyperlactatemia. Five patients on a long-term schedule of linezolid treatment
were studied during the acute phase of hyperlactatemia and after clinical recovery and lactate
normalization following linezolid withdrawal. Mitochondrial studies were performed with
peripheral blood mononuclear cells and consisted of measurement of mitochondrial mass,
mitochondrial protein synthesis homeostasis (cytochrome c oxidase [COX] activity, COX-II
subunit expression, COX-II mRNA abundance, and mitochondrial DNA [mtDNA] content),
and overall mitochondrial function (mitochondrial membrane potential and intact-cell
oxidative capacity). During linezolid-induced hyperlactatemia, we found extremely reduced
protein expression (16% of the remaining content compared to control values [100%], P <
0.001) for the mitochondrially coded, transcribed, and translated COX-II subunit.
Accordingly, COX activity was also found to be decreased (51% of the remaining activity, P
< 0.05). These reductions were observed despite the numbers of COX-II mitochondrial RNA
transcripts being abnormally increased (297%, P = 0.10 [not significant]) and the
mitochondrial DNA content remaining stable. These abnormalities persisted even after the
correction for mitochondrial mass, which was mildly decreased during the hyperlactatemic
phase. Most of the mitochondrial abnormalities returned to control ranges after linezolid
withdrawal, lactate normalization, and clinical recovery. Linezolid inhibits mitochondrial
protein synthesis, leading to decreased mitochondrial enzymatic activity, which causes
linezolid-related hyperlactatemia, which resolves upon discontinuation of linezolid treatment.
Supplemental Content
Nucleic Acids Symp Ser (Oxf). 2005;(49):253-4.
Crystallographic studies of Homo sapiens
ribosomal decoding A site complexed with
aminoglycosides.
Kondo J, François B, Urzhumtsev A, Westhof E.
Source
Institut de Biologie Moléculaire et Cellulaire, UPR9002 CNRS, Université Louis Pasteur, 15
rue René Descartes, 67084 Strasbourg, France.
Abstract
Aminoglycosides are highly effective antibacterial drugs that decrease translation accuracy by
binding to the aminoacyl-tRNA decoding site (A site) of 16S ribosomal RNA. On the other
hand, they are highly toxic to mammals through kidney and ear-associated illnesses by
binding to ribosomal A sites. To understand the mechanism of toxicity of aminoglycosides to
mammals at atomic level, crystallographic studies have been carried out with a number of
Homo sapiens mitochondrial and cytoplasmic A sites complexed with aminoglycosides.
Several X-ray diffraction data sets were successfully collected. Initial phases of mitochondrial
A site with tobramycin and cytoplasmic A site with paromomycin were derived by the
molecular replacement method. Refinements of atomic parameters are now under progress.
Supplemental Content
Clin Infect Dis. 2005 Jun 15;40(12):e113-6. Epub 2005 May 3.
Does linezolid cause lactic acidosis by
inhibiting mitochondrial protein synthesis?
Palenzuela L, Hahn NM, Nelson RP Jr, Arno JN, Schobert C, Bethel R, Ostrowski LA,
Sharma MR, Datta PP, Agrawal RK, Schwartz JE, Hirano M.
Source
Department of Neurology, Columbia University College of Physicians and Surgeons, New
York, USA.
Abstract
Linezolid, an oxazolidinone antibiotic, inhibits bacterial protein synthesis by binding to 23S
ribosomal RNA (rRNA). We studied 3 patients who experienced lactic acidosis while
receiving linezolid therapy. The toxicity may have been caused by linezolid binding to
mitochondrial 16S rRNA. Genetic polymorphisms may have contributed to the toxicity in 2
patients.
Supplemental Content
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2004 Dec;148(2):221-3.
Influence of amphotericin B deoxycholate
or amphotericin B colloidal dispersion on
renal tubule epithelium in rat.
Krejcírová L, Lauschová I, Horký D, Doubek M, Mayer J, Doubek J.
Source
Department of Histology and Embryology, Medicine Faculty Masaryk University Brno,
Czech Republic. [email protected]
Abstract
Amphotericin B deoxycholate (AmB) or Amphotericin B colloidal dispersion (ABCD) are
used in clinics for the treatment of systemic fungal infections. The goal of our study was to
compare the nephrotoxicity of these drugs in rat kidney. The effects of AmB and ABCD on
the ultrastructure of the epithelium of renal tubules were studied and evaluated using
morphometric and statistical methods. Two groups of 3 animals were established: group 1
was treated with AmB desoxycholate and group 2, to which ABCD was applied. AmB caused
more than ABCD ultrastructural changes in the cytoplasm of the epithelial cells: damage to
mitochondria, vacuolation of cytoplasm, and increased values of volume density of
peroxisomes. However, we failed to observe significant differences in morphology and
density of the other cell organelles. The proximal tubules seemed to be more sensitive to the
nephrotoxic influence of both formulas than the distal tubules of rat kidney. Although, AmB
causes more severe damage than ABCD, both drugs cause damage to renal tubuli.
Supplemental Content
Am J Physiol Renal Physiol. 2004 Apr;286(4):F617-24. Epub 2003 Nov 18.
Gentamicin traffics retrograde through the
secretory pathway and is released in the
cytosol via the endoplasmic reticulum.
Sandoval RM, Molitoris BA.
Source
Indiana Univ. School of Medicine, 950 West Walnut, R2-E251, Indianapolis, IN 46202, USA.
[email protected]
Abstract
Previous mechanisms describing how aminoglycosides exert their cellular toxicity, including
lysosomal accumulation, rupture, and release, cannot account for the rapidity and extent of the
observed subcellular and organ effects. Using immunoamplification techniques and
colocalization with epitopes of the endoplasmic reticulum (ER), we report rapid retrograde
transport of gentamicin to the ER. Additionally, exposure times of 2 and 4 h in LLC-PK1
cells produced cytosolic release and nuclear association. Cellular internalization and
trafficking of aminoglycoside structural analogs, amine-containing cationic fluorescent
dextrans of 3,000 molecular weight, corroborated these findings. However, identical anionic
fluorescent dextrans, or larger cationic dextrans, of 10,000 molecular weight, failed to
traverse from the ER into the cytosol or localize within the nucleus. These studies suggest that
a pathway exists that transports internalized aminoglycosides, and other small-molecularweight cationic compounds, in a retrograde manner through the Golgi complex and to the ER.
From there, these compounds move into the cytosol for delivery throughout the cell. To
quantify the potential toxic effects of cytosolic aminoglycoside release, experiments
examining mitochondrial membrane potential in the continued presence of extracellular
gentamicin were undertaken and demonstrated a significant reduction after 4 and 8 h. These
observations provide a mechanism for the rapidly induced known cellular alterations,
including aberrant vesicle fusion, mitochondrial toxicity/free radical generation, and
decreased protein synthesis either by reduced transcription or translation after aminoglycoside
exposure.
Supplemental Content
Mol Pharmacol. 2002 Jun;61(6):1348-58.
A novel beta-lactam antibiotic activates
tumor cell apoptotic program by inducing
DNA damage.
Smith DM, Kazi A, Smith L, Long TE, Heldreth B, Turos E, Dou QP.
Source
Drug Discovery Program, and the Department of Chemistry, College of Arts and Sciences,
University of South Florida, Tampa, Florida 33612-9497, USA.
Abstract
Many of the anticancer drugs in current use are toxic and thus limited in their efficacy. It
therefore becomes essential to develop novel chemotherapeutic agents with lower levels of
toxicity. The beta-lactam antibiotics have been used for many years to treat bacterial
infections with limited or no toxicity. Until now, it has never been shown that beta-lactams
could kill tumor cells. Here, for the first time, we have discovered and characterized the
apoptosis-inducing properties of a family of novel beta-lactam antibiotics against human
leukemia, breast, prostate, and head-and-neck cancer cells. We found that one particular lead
compound (lactam 1) with an N-methylthio group was able to induce DNA damage and
inhibit DNA replication in Jurkat T cells within a 2-h treatment. This was followed by p38
mitogen-activated protein kinase activation, S phase arrest, and apoptotic cell death. p38 was
found to be a central player in beta-lactam-induced apoptosis and resided downstream of
DNA damage but upstream of caspase activation. Accompanying caspase-8 activation was
cleavage of the pro-apoptotic Bcl-2 family protein Bid, and release of the mitochondrial
cytochrome c. This was also associated with activation of caspase-9 and -3. Analogs of lactam
1 in which the N-methylthio group was replaced with other organothio chains exhibited
progressive decreased potencies to induce DNA damage, p38 kinase activation, S phase
arrest, and apoptosis, demonstrating requirement of the N-methylthio group. Because of the
ease of synthesis and structural manipulation, we believe these beta-lactams may have the
potential to be developed into anticancer agents.
Supplemental Content
Basic Clin Pharmacol Toxicol. 2008 Oct;103(4):349-53. Epub 2008 Jul 18.
Chloramphenicol-induced oxidative stress
in human neutrophils.
Páez PL, Becerra MC, Albesa I.
Department of Pharmacy, Faculty of Chemical Sciences, National University of Córdoba,
Córdoba, Argentina.
Abstract
The aim of this study was to evaluate the in vitro effect of chloramphenicol in order to
determine its potential toxic effects on human neutrophils, by using assays of reactive oxygen
species (ROS) determination, nitrite measurement and antioxidant systems. Chloramphenicol
enabled the oxidative stress response of neutrophils and increased the ROS production at 2, 4,
8 and 16 microg/ml, while ROS generation decreased at high concentrations (32 microg/ml).
The nitroblue tetrazolium assay shows that neutrophils incubated with chloramphenicol
increased the intracellular ROS, with the extracellular production rising with a corresponding
increase in antibiotic concentration. Enzymatic activities--superoxide dismutase, catalase and
diaphorase enzymes--increased after chloramphenicol treatment, while the glutathione level
decreased in neutrophils incubated with antibiotic. The results obtained in the present work
suggest that the study of susceptibility to oxidative stress in neutrophils before
chloramphenicol treatment could be adequate for in vitro toxicity screening.
PMID: 18684218 [PubMed - indexed for MEDLINE]
Supplemental Content
J Enzyme Inhib Med Chem. 2008 Feb;23(1):144-8.
Effects of some antibiotics on human
erythrocyte glutathione reductase: an in
vitro study.
Senturk M, Kufrevioglu OI, Ciftci M.
Department of Chemistry, Ataturk University, Erzurum, Turkey.
Abstract
Inhibitory effects of some antibiotics on purified human erythrocyte glutathione reductase
were investigated. Human erythrocyte glutathione reductase was purified 2800-fold (29%
yield) at 4 degrees C using 2', 5'-ADP Sepharose 4B affinity gel and Sephadex G-200 gel
filtration chromatography. SDS polyacrylamide gel electrophoresis showed a single band for
the enzyme. Imipenem, rifamycin, sulfanylacetamide, ceftazidime, chloramphenicol,
seftriaxon, vancomycin, cefuroxime and ornidazole exhibited inhibitory effects but
clindamycin, lincomycin, amoxicillin, amikacin exhibited activatory effects on the enzyme in
vitro. The IC(50) values of imipenem, rifamycin, sulfanylacetamide, ceftazidime,
chloramphenicol, seftriaxon, vancomycin, cefuroxime and ornidazole were 0.030, 0.146, 0.59,
2.476, 2.36, 2.88, 4.83, 15.43 and 19.632 mM, respectively, and the K(i) constants were 0.06
+/- 0.01, 0.275 +/- 0.10, 0.85 +/- 0.05, 3.59 +/- 0.51, 3.85 +/- 0.40, 3.71 +/- 0.60, 15.11 +/2.50, 23.50 +/- 2.94 and 28.49 +/- 6.50 mM, respectively. While imipenem, rifamycin,
sulfanylacetamide, ceftazidime, chloramphenicol and seftriaxon cefuroxime and ornidazole
showed competitive inhibition, vankomycine displayed noncompetitive inhibition.
PMID: 18341267 [PubMed - indexed for MEDLINE]
Supplemental Content
Isoniazid induces oxidative stress,
mitochondrial dysfunction and apoptosis in
Hep G2 cells.
Bhadauria S, Singh G, Sinha N, Srivastava S.
Division of Toxicology, Central Drug Research Institute, Lucknow, India.
[email protected]
Abstract
Isoniazid (INH) continues to be a sheet anchor in treatment of tuberculosis, however its
chronic administration is known to cause hepatotoxicity through a poorly defined mechanism.
Ellucidation of mechanism underlying INH induced hepatotoxicity may be beneficial in
devising ways to counteract toxic manifestations. In view of this concentration dependent
effects INH were evaluated in hepatoma cell line (Hep-G2). INH exposure produced cytotoxic
effects in Hep-G2 cells in a characteristic dose dependent manner. There was considerable
cell detachment, loss of viability and alterations in cellular morphology that were indicative of
toxic insult. We observed cell shrinkage at highest concentrations (88 microM) suggesting an
involvement of apoptosis. This finding was substantiated by the flow cytometry data and
DNA fragmentation analysis which clearly indicated that INH induced cytotoxicity, was
being mediated by induction of apoptosis. Furthermore there was mitochondrial dysfunction
as indicated by significant inhibition of MTT Reduction as compared to control at all the
concentrations and depletion of cellular glutathione (GSH) content along with increased
production of Reactive oxygen species (ROS). Collectively these findings led us to conclude
that INH induced apoptosis in Hep-G2 cells is mediated by generation of oxidative stress.
Toxicol Appl Pharmacol. 2006 Sep 1;215(2):158-67. Epub 2006 Apr 17.
Bioactivation, protein haptenation, and
toxicity of sulfamethoxazole and dapsone in
normal human dermal fibroblasts.
Bhaiya P, Roychowdhury S, Vyas PM, Doll MA, Hein DW, Svensson CK.
Division of Pharmaceutics, College of Pharmacy, The University of Iowa, Iowa City, IA
52242, USA.
Abstract
Cutaneous drug reactions (CDRs) associated with sulfonamides are believed to be mediated
through the formation of reactive metabolites that result in cellular toxicity and protein
haptenation. We evaluated the bioactivation and toxicity of sulfamethoxazole (SMX) and
dapsone (DDS) in normal human dermal fibroblasts (NHDF). Incubation of cells with DDS or
its metabolite (D-NOH) resulted in protein haptenation readily detected by confocal
microscopy and ELISA. While the metabolite of SMX (S-NOH) haptenated intracellular
proteins, adducts were not evident in incubations with SMX. Cells expressed abundant Nacetyltransferase-1 (NAT1) mRNA and activity, but little NAT2 mRNA or activity. Neither
NAT1 nor NAT2 protein was detected. Incubation of NHDF with S-NOH or D-NOH
increased reactive oxygen species formation and reduced glutathione content. NHDF were
less susceptible to the cytotoxic effect of S-NOH and D-NOH than are keratinocytes. Our
studies provide the novel observation that NHDF are able to acetylate both arylamine
compounds and bioactivate the sulfone DDS, giving rise to haptenated proteins. The reactive
metabolites of SMX and DDS also provoke oxidative stress in these cells in a time- and
concentration-dependent fashion. Further work is needed to determine the role of the observed
toxicity in mediating CDRs observed with these agents.
PMID: 16603214 [PubMed - indexed for MEDLINE]PMCID: PMC1615915Free PMC
Article
Supplemental Content
J Biol Chem. 2006 Feb 10;281(6):3382-8. Epub 2005 Dec 14.
Aminoglycosides decrease glutathione
peroxidase-1 activity by interfering with
selenocysteine incorporation.
Handy DE, Hang G, Scolaro J, Metes N, Razaq N, Yang Y, Loscalzo J.
Department of Medicine, Brigham and Women's Hospital and Harvard Medical School,
Boston, Massachusetts 02115, USA. [email protected]
Erratum in:

J Biol Chem. 2009 Sep 11;284(37):25459.
Abstract
Cellular glutathione peroxidase is a key intracellular antioxidant enzyme that contains a
selenocysteine residue at its active site. Selenium, a selenocysteine incorporation sequence in
the 3'-untranslated region of the glutathione peroxidase mRNA, and other translational
cofactors are necessary for "read-through" of a UGA stop codon that specifies selenocysteine
incorporation. Aminoglycoside antibiotics facilitate read-through of premature stop codons in
prokayotes and eukaryotes. We studied the effects of G418, an aminoglycoside, on cellular
glutathione peroxidase expression and function in mammalian cells. Insertion of a
selenocysteine incorporation element along with a UGA codon into a reporter construct
allows for read-through only in the presence of selenium. G418 increased read-through in
selenium-replete cells as well as in the absence of selenium. G418 treatment increased
immunodetectable endogenous or recombinant glutathione peroxidase but reduced the
specific activity of the enzyme. Tandem mass spectrometry experiments indicated that G418
caused a substitution of l-arginine for selenocysteine. These data show that G418 can affect
the biosynthesis of this key antioxidant enzyme by promoting substitution at the UGA codon.
PMID: 16354666 [PubMed - indexed for MEDLINE]PMCID: PMC1472404Free PMC
Article
Supplemental Content
Drug Chem Toxicol. 2005;28(4):433-45.
Effects of some antibiotics on activity of
glucose-6-phosphate dehydrogenase from
human erythrocytes in vitro and effect of
isepamicin sulfate on activities of
antioxidant enzymes in rat erythrocytes.
Ozmen I, Küfrevioğlu OI, Gul M.
Biotechnology Application and Research Center, Atatürk University, Erzurum, Turkey.
[email protected]
Abstract
The purpose of this study was to investigate effects of some antibiotics on glucose-6phosphate dehydrogenase (G6PD), antioxidant enzymes, and malondialdehyde (MDA).
Initially, for in vitro studies, G6PD was purified from human erythrocyte, 9811-fold in a yield
of 42.4% by using ammonium sulfate precipitation and 2',5' ADP-Sepharose 4B affinity gel.
The purified enzyme showed a single band on sodium dodecyl sulfate polyacrylamide gel
electrophoresis (SDS-PAGE). The effects of four different antibiotics (isepamicin sulfate,
meropenem, chloramphenicol, and thiamphenicol glisinat hydrochloride) were investigated on
the purified enzyme. K(i) value and type of inhibition were determined by means of
Lineweaver-Burk graphs and regression analysis graphs. Isepamicin sulfate inhibited the
enzyme activity (I(50) value, 2.1 mM; K(i) value, 1.7 mM), whereas thiamphenicol glisinat
hydrochloride activated the G6PD dose dependently. Other drugs showed no inhibition and
activation effect. In addition, the effects of isepamicin sulfate on the activities of G6PD,
glutathione reductase (GR), superoxide dismutases (SOD), glutathione peroxidase (GPx),
catalase (CAT), and glutathione S-transferase (GST) and MDA concentrations were examined
in Sprague-Dawley rat erythrocytes in vivo. A marked alteration in the activities of these
enzymes and MDA levels may be the result of oxidative stress in the rats receiving isepamicin
sulfate.
PMID: 16298874 [PubMed - indexed for MEDLINE]
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Antimicrob Agents Chemother. 2005 Sep;49(9):3784-8.
Assessment of effective renal plasma flow,
enzymuria, and cytokine release in healthy
volunteers receiving a single dose of
amphotericin B desoxycholate.
Pai MP, Norenberg JP, Telepak RA, Sidney DS, Yang S.
College of Pharmacy, MSC09 5360, University of New Mexico, Albuquerque, NM 871310001, USA. [email protected].
Erratum in:

Antimicrob Agents Chemother. 2005 Oct;49(10):4427.
Abstract
The present study assessed potential subclinical markers of amphotericin B (AmB)-related
nephrotoxicity and infusion-related reactions (IRR). Subjects were pretreated with
diphenhydramine and acetaminophen and received a 500-ml bolus infusion of 0.9% sodium
chloride prior to each effective renal plasma flow (ERPF) assessment. ERPF was measured
before and after administration of a single 0.25-mg/kg intravenous AmB dose using
technetium-99m mercaptoacetyltriglycine. Blood was collected before and 3 h after AmB
infusion for tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) plasma
concentrations. Overnight 12-h urine collections were performed before administration of
AmB and for 2 nights after administration of AmB and analyzed for alpha and pi glutathioneS-transferases (GSTalpha and GSTpi, respectively) and N-acetyl-beta-d-glucosaminidase
(NAG). Six men and six women with mean +/- standard deviation (SD) ages of 24.8 +/- 5.3
and 28.0 +/- 8.5 years, respectively, were studied. Baseline serum creatinine values were
within the normal range and were unaltered after administration of AmB. The mean +/- SD
decrease in ERPF after administration of AmB was significant (P < 0.05) in males (15.7 +/8.1%) but not females (9.5 +/- 14.0%). The GSTpi and GSTalpha indices increased
significantly (P < 0.05) by two to fourfold and returned to baseline in males but were
unaltered in females. NAG indices were unaffected by AmB. Six patients experienced an IRR
that was associated with increased TNF-alpha (P < 0.05) but not IL-1beta (P = 0.09). These
results suggest a potential sex-related difference in AmB-induced nephrotoxicity and provide
a rationale for use of ERPF, urine GST, and TNF-alpha as subclinical markers of polyeneinduced toxicity.
PMID: 16127053 [PubMed - indexed for MEDLINE]PMCID: PMC1195419Free PMC
Article
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Neuroscience. 2005;133(4):959-67.
Involvement of mitochondrial potential and
calcium buffering capacity in minocycline
cytoprotective actions.
Fernandez-Gomez FJ, Galindo MF, Gomez-Lazaro M, González-García C, Ceña V, Aguirre
N, Jordán J.
Departamento de Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La
Mancha, Avenida Almansa, s/n, 02006 Albacete, Spain.
Abstract
Minocycline, a semisynthetic derivative of tetracycline, displays beneficial activity in
neuroprotective in models including, Parkinson disease, spinal cord injury, amyotrophic
lateral sclerosis, Huntington disease and stroke. The mechanisms by which minocycline
inhibits apoptosis remain poorly understood. In the present report we have investigated the
effects of minocycline on mitochondria, due to their crucial role in apoptotic pathways. In
mitochondria isolated suspensions, minocycline failed to block superoxide-induced swelling
but was effective in blocking mitochondrial swelling induced by calcium. This latter effect
might be mediated through dissipation of mitochondrial transmembrane potential and
blockade of mitochondrial calcium uptake. Consistently, minocycline fails to protect SHSY5Y cell cultures against reactive oxygen species-mediated cell death, including malonate
and 6-hydroxydopamine treatments, but it is effective against staurosporine-induced
cytotoxicity. The effects of this antibiotic on mitochondrial respiratory chain complex were
also analyzed. Minocycline did not modify complex IV activity, and only at the higher
concentration tested (100 microM) inhibited complex II/III activity. Other members of the
minocycline antibiotic family like tetracycline failed to induce these mitochondrial effects.
PMID: 15964487 [PubMed - indexed for MEDLINE]
Supplemental Content
J Toxicol Sci. 2008 Feb;33(1):85-96.
Links
An aminoglycoside antibiotic gentamycin induces
oxidative stress, reduces antioxidant reserve and
impairs spermatogenesis in rats.
Narayana K.
Department of Anatomy, Faculty of Medicine, HSC, Kuwait University, Safat,
Kuwait. [email protected]
Gentamycin (GS) is an aminoglycoside antibiotic used to treat infections of various
Gram-negative organisms. The present study was designed to investigate the effects of
GS on oxidative stress, antioxidant levels, testicular structure and sperm parameters in
the rat. Adult Wistar rats (12 week old; N=7/group) were treated (i. p.) with 0 mg/kg,
3 mg/kg and 5 mg/kg for 10 days at an interval of 24 hr between subsequent
treatments. Animals were sacrificed on days 1 and 35 after the last treatment, and the
reproductive organs were removed and weights of testis and seminal vesicle were
recorded. The right testis was processed for light microscopic analysis. The left testis
was homogenized and step 19 spermatids were counted to determine the daily sperm
production (DSP) and daily abnormal sperm production (DASP). The sperm count,
sperm motility and incidence of abnormal sperms were estimated in the epididymis. In
testicular sections, along with the evaluation of qualitative changes, the seminiferous
tubule diameter (STD) and the epithelial height (SE) were measured. The incidence of
stage XIV tubules in testicular sections, meiotic figures and step 14 spermatids/stage
XIV tubule, and step 19 spermatids/stage VII tubule were estimated. Intra-testicular
levels of superoxide anion, lipid peroxidation and antioxidants-superoxide dismutase
(SOD), catalase, glutathione peroxidase (GPx) and ascorbic acid were measured. GS
did not affect the body weight, but the testis weight and DSP were decreased at 5
mg/kg dose-level on both days (p<0.05), and the weight of seminal vesicle decreased
on day 35 at both dose-levels. The DASP was increased in a dose-dependent manner
(p<0.05) on days 1 and 35 at both dose-levels. The sperm count was decreased at both
dose-levels on day 35, whereas the sperm motility was decreased and sperm
abnormality was increased on day 1 at 5 mg/kg and on day 35 at both dose-levels. GS
induced structural changes such as sloughing of seminiferous epithelium, vacuoles and
gaps in the epithelium, nuclear pyknosis and atrophic changes in a few tubules. The
tubular shrinkage was observed as indicated by decreased STD and SE on both days at
5 mg/kg dose-level. Incidence of stage XIV tubules and step 19 spermatids/stage VII
tubule decreased on all time points at all dose-levels, whereas the step 14 spermatids
and meiotic figures decreased on day 35 at both dose-levels (p<0.05). The free radicalsuperoxide anion concentration was significantly increased on day 1 in a dosedependent pattern (p<0.05). However, activities of all 3 enzymatic antioxidants and
ascorbic acid level decreased in a dose-dependent pattern on day 1 (p<0.05), except
the GPx, which was also decreased on day 35 at 5 mg/kg dose-level. There was a
significant rise in the thiobarbituric acid reactive substances on day 1 indicating
increased lipid peroxidation in the testis. In conclusion, GS induces an oxidative
stress-status in the testis by increasing free radical formation and lipid peroxidation,
and by decreasing the antioxidant reserves. These biochemical changes manifest as
structural and cytotoxic changes in the testis. Further, GS also affects the spermatozoa
by affecting their number, motility and morphology.
PMID: 18303187 [PubMed - indexed for MEDLINE]
Free Radic Biol Med. 2010 Dec 1;49(11):1666-73. Epub 2010 Aug 31.
An oxidative environment promotes growth
of Mycobacterium abscessus.
Oberley-Deegan RE, Rebits BW, Weaver MR, Tollefson AK, Bai X, McGibney M, Ovrutsky
AR, Chan ED, Crapo JD.
Source
Department of Medicine, National Jewish Health, Denver, CO 80206, USA.
[email protected]
Abstract
Mycobacterium abscessus infections, particularly those causing chronic lung diseases, are
becoming more prevalent worldwide. M. abscessus infections are difficult to treat because of
antibiotic resistance. Thus, new treatment options are urgently needed. M. abscessus is an
intracellular pathogen that primarily infects macrophages and fibroblasts. Because this
bacterium has only recently been identified as a separate species, very little is known about
M. abscessus-host interactions and how M. abscessus growth is regulated. Oxidative stress
has long been shown to inhibit the growth of bacterial organisms. However, some intracellular
bacteria, such as Mycobacterium tuberculosis, grow well in oxidizing environments. In this
study, we show that M. abscessus infection causes the host cell environment to become more
oxidizing. Furthermore, we show that a more oxidizing environment leads to enhanced
growth of M. abscessus inside macrophages. In the presence of antioxidants, MnTE-2-PyP
(chemical name: manganese(II) meso-tetrakis-(N-methylpyridinium-2-yl) porphyrin) or N-
acetyl-l-cysteine, M. abscessus growth is inhibited. These results lead us to postulate that
antioxidants may aid in the treatment of M. abscessus infections.
Copyright © 2010 Elsevier Inc. All rights reserved.
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