Overexpression of Na(+)/K (+)-ATPase parallels the increase in sodium transport and potassium recycling in an in vitro model of proximal tubule cellular ageing.
AuthorsSilva E, Gomes P, Soares-da-Silva P,
JournalJ Membr Biol
PubMed ID17334838
'Na(+)/K(+)-ATPase plays a key role in the transport of Na(+) throughout the nephron, but ageing appears to be accompanied by changes in the regulation and localization of the pump. In the present study, we examined the effect of in vitro cell ageing on the transport of Na(+) and K(+) ions ... More
Reactive oxygen species production via NADPH oxidase mediates TGF-beta-induced cytoskeletal alterations in endothelial cells.
AuthorsHu T, Ramachandrarao SP, Siva S, Valancius C, Zhu Y, Mahadev K, Toh I, Goldstein BJ, Woolkalis M, Sharma K
JournalAm J Physiol Renal Physiol
PubMed ID16159901
'Cytoskeletal alterations in endothelial cells have been linked to nitric oxide generation and cell-cell interactions. Transforming growth factor (TGF)-beta has been described to affect cytoskeletal rearrangement in numerous cell types; however, the underlying pathway is unclear. In the present study, we found that human umbilical vein endothelial cells (HUVEC) have ... More
Subcellular localization of Nox4 and regulation in diabetes.
AuthorsBlock K, Gorin Y, Abboud HE,
JournalProc Natl Acad Sci U S A
PubMed ID19706525
'Oxidative stress is implicated in human diseases. Some of the oxidative pathways are harbored in the mitochondria. NAD(P)H oxidases have been identified not only in phagocytic but also in somatic cells. Nox4 is the most ubiquitous of these oxidases and is a major source of reactive oxygen species (ROS) in ... More
Continuous translocation of Rac2 and the NADPH oxidase component p67(phox) during phagocytosis.
Authorsvan Bruggen R, Anthony E, Fernandez-Borja M, Roos D
JournalJ Biol Chem
PubMed ID14623873
'In this study, the translocation of the NADPH oxidase components p67(phox) and Rac2 was studied during phagocytosis in living cells. For this purpose, green fluorescent protein (GFP)-tagged versions of these proteins were expressed in the myeloid cell line PLB-985. First, the correct localization of p67GFP and GFP-Rac2 was shown during ... More
The E-loop is involved in hydrogen peroxide formation by the NADPH oxidase Nox4.
AuthorsTakac I, Schröder K, Zhang L, Lardy B, Anilkumar N, Lambeth JD, Shah AM, Morel F, Brandes RP,
JournalJ Biol Chem
PubMed ID21343298
'In contrast to the NADPH oxidases Nox1 and Nox2, which generate superoxide (O(2)(·-)), Nox4 produces hydrogen peroxide (H(2)O(2)). We constructed chimeric proteins and mutants to address the protein region that specifies which reactive oxygen species is produced. Reactive oxygen species were measured with luminol/horseradish peroxidase and Amplex Red for H(2)O(2) ... More
Mechanisms of the genotoxicity of crocidolite asbestos in mammalian cells: implication from mutation patterns induced by reactive oxygen species.
AuthorsXu A, Zhou H, Yu DZ, Hei TK
JournalEnviron Health Perspect
PubMed ID12361925
'Asbestos is an important environmental carcinogen in the United States and remains the primary occupational concern in many developing countries; however, the underlying mechanisms of its genotoxicity are not known. We showed previously that asbestos is a potent gene and chromosomal mutagen in mammalian cells and that it induces mostly ... More
'Many areas of research today are based on enzymatic assays most of which are still performed as enzyme-linked immunosorbent assays in microtiter plates. The demand for highly parallel screening of thousands of samples eventually led to a miniaturization and automation of these assays. However, the final transfer of enzymatic assays ... More
Doxorubicin increases intracellular hydrogen peroxide in PC3 prostate cancer cells.
'We studied the effect of doxorubicin on the production of hydrogen peroxide by PC3 human prostate cancer cells, using a sensitive assay based on aminotriazole-mediated inhibition of catalase. PC3 cells exposed to increasing concentrations of doxorubicin had an increase in intracellular hydrogen peroxide that was concentration-dependent up to 1 microM ... More
Elevated mitochondrial reactive oxygen species generation affects the immune response via hypoxia-inducible factor-1alpha in long-lived Mclk1+/- mouse mutants.
AuthorsWang D, Malo D, Hekimi S,
JournalJ Immunol
PubMed ID20007531
'Mitochondrial reactive oxygen species (ROS) are believed to stabilize hypoxia-inducible factor (HIF)-1alpha, a transcriptional regulator of the immune response. Mclk1 encodes a mitochondrial protein that is necessary for ubiquinone biosynthesis. Heterozygote Mclk1(+/-) mutant mice are long-lived despite increased mitochondrial ROS and decreased energy metabolism. In this study, Mclk1(+/-) mutant mice ... More
Spatiotemporal compartmentalization of key physiological processes during muscle precursor differentiation.
AuthorsOzbudak EM, Tassy O, Pourquié O,
JournalProc Natl Acad Sci U S A
PubMed ID20160088
'The development of multicellular organisms is controlled by transcriptional networks. Understanding the role of these networks requires a full understanding of transcriptome regulation during embryogenesis. Several microarray studies have characterized the temporal evolution of the transcriptome during development in different organisms [Wang QT, et al. (2004) Dev Cell 6:133-144; Furlong ... More
Chromate-reducing properties of soluble flavoproteins from Pseudomonas putida and Escherichia coli.
AuthorsAckerley DF, Gonzalez CF, Park CH, Blake R, Keyhan M, Matin A
JournalAppl Environ Microbiol
PubMed ID14766567
'Cr(VI) (chromate) is a toxic, soluble environmental contaminant. Bacteria can reduce chromate to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of interest. Genetic and protein engineering of suitable enzymes can improve bacterial bioremediation. Many bacterial enzymes catalyze one-electron reduction of chromate, generating Cr(V), which redox cycles, ... More
Stabilization of enzymes in silk films.
AuthorsLu S, Wang X, Lu Q, Hu X, Uppal N, Omenetto FG, Kaplan DL,
JournalBiomacromolecules
PubMed ID19323497
'Material systems are needed that promote stabilization of entrained molecules, such as enzymes or therapeutic proteins, without destroying their activity. We demonstrate that the unique structure of silk fibroin protein, when assembled into the solid state, establishes an environment that is conducive to the stabilization of entrained proteins. Enzymes (glucose ... More
Motor deficit in a Drosophila model of mucolipidosis type IV due to defective clearance of apoptotic cells.
'Disruption of the Transient Receptor Potential (TRP) mucolipin 1 (TRPML1) channel results in the neurodegenerative disorder mucolipidosis type IV (MLIV), a lysosomal storage disease with severe motor impairments. The mechanisms underlying MLIV are poorly understood and there is no treatment. Here, we report a Drosophila MLIV model, which recapitulates the ... More
Uncoupling Lipid Metabolism from Inflammation through Fatty Acid Binding Protein-Dependent Expression of UCP2.
AuthorsXu H, Hertzel AV, Steen KA, Wang Q, Suttles J, Bernlohr DA,
Journal
PubMed ID25582199
'Chronic inflammation in obese adipose tissue is linked to endoplasmic reticulum (ER) stress and systemic insulin resistance. Targeted deletion of the murine fatty acid binding protein (FABP4/aP2) uncouples obesity from inflammation although the mechanism underlying this finding has remained enigmatic. Here, we show that inhibition or deletion of FABP4/aP2 in ... More
Sensory neurons and schwann cells respond to oxidative stress by increasing antioxidant defense mechanisms.
AuthorsVincent AM, Kato K, McLean LL, Soules ME, Feldman EL,
JournalAntioxid Redox Signal
PubMed ID19072199
'Elevated blood glucose is a key initiator of mechanisms leading to diabetic neuropathy. Increases in glucose induce acute mitochondrial oxidative stress in dorsal root ganglion (DRG) neurons, the sensory neurons normally affected in diabetic neuropathy, whereas Schwann cells are largely unaffected. We propose that activation of an antioxidant response in ... More
Murine prolylcarboxypeptidase depletion induces vascular dysfunction with hypertension and faster arterial thrombosis.
AuthorsAdams GN, LaRusch GA, Stavrou E, Zhou Y, Nieman MT, Jacobs GH, Cui Y, Lu Y, Jain MK, Mahdi F, Shariat-Madar Z, Okada Y, D'Alecy LG, Schmaier AH,
JournalBlood
PubMed ID21297000
'Prolylcarboxypeptidase (PRCP) activates prekallikrein to plasma kallikrein, leading to bradykinin liberation, and degrades angiotensin II. We now identify PRCP as a regulator of blood vessel homeostasis. ß-Galactosidase staining in PRCP(gt/gt) mice reveals expression in kidney and vasculature. Invasive telemetric monitorings show that PRCP(gt/gt) mice have significantly elevated blood pressure. PRCP(gt/gt) ... More
Distinct mechanisms for aerenchyma formation in leaf sheaths of rice genotypes displaying a quiescence or escape strategy for flooding tolerance.
AuthorsParlanti S, Kudahettige NP, Lombardi L, Mensuali-Sodi A, Alpi A, Perata P, Pucciariello C,
JournalAnn Bot
PubMed ID21489969
'Rice is one of the few crops able to withstand periods of partial or even complete submergence. One of the adaptive traits of rice is the constitutive presence and further development of aerenchyma which enables oxygen to be transported to submerged organs. The development of lysigenous aerenchyma is promoted by ... More
The ferroxidase activity of yeast frataxin.
AuthorsPark S, Gakh O, Mooney SM, Isaya G
JournalJ Biol Chem
PubMed ID12149269
'Frataxin is required for maintenance of normal mitochondrial iron levels and respiration. The mature form of yeast frataxin (mYfh1p) assembles stepwise into a multimer of 840 kDa (alpha(48)) that accumulates iron in a water-soluble form. Here, two distinct iron oxidation reactions are shown to take place during the initial assembly ... More
A highly sensitive fluorescent micro-assay of H2O2 release from activated human leukocytes using a dihydroxyphenoxazine derivative.
'This study describes a simple, reliable, highly sensitive and quantitative fluorescence microplate-assay of H2O2 from activated leukocytes using a novel horse radish peroxidase (HRP) substrate N-acetyl-3,7-dihydroxyphenoxazine (A6550). Unlike the widely used fluorescent HRP substrate scopoletin, A6550 is non-fluorescent and becomes highly fluorescent upon HRP-catalyzed H2O2 oxidation. Using 50 microM A6550, ... More
Hyperoxia-induced NAD(P)H oxidase activation and regulation by MAP kinases in human lung endothelial cells.
AuthorsParinandi NL, Kleinberg MA, Usatyuk PV, Cummings RJ, Pennathur A, Cardounel AJ, Zweier JL, Garcia JG, Natarajan V
JournalAm J Physiol Lung Cell Mol Physiol
PubMed ID12388366
'Hyperoxia increases reactive oxygen species (ROS) production in vascular endothelium; however, the mechanisms involved in ROS generation are not well characterized. We determined the role and regulation of NAD(P)H oxidase in hyperoxia-induced ROS formation in human pulmonary artery endothelial cells (HPAECs). Exposure of HPAECs to hyperoxia for 1, 3, and ... More
Kinetic isotope effect studies on the de novo rate of chromophore formation in fast- and slow-maturing GFP variants.
'The maturation process of green fluorescent protein (GFP) entails a protein oxidation reaction triggered by spontaneous backbone condensation. The chromophore is generated by full conjugation of the Tyr66 phenolic group with the heterocycle, a process that requires C-H bond scission at the benzylic carbon. We have prepared isotope-enriched protein bearing ... More
Rotenone model of Parkinson disease: multiple brain mitochondria dysfunctions after short term systemic rotenone intoxication.
AuthorsPanov A, Dikalov S, Shalbuyeva N, Taylor G, Sherer T, Greenamyre JT
JournalJ Biol Chem
PubMed ID16243845
'Chronic infusion of rotenone (Rot) to Lewis rats reproduces many features of Parkinson disease. Rot (3 mg/kg/day) was infused subcutaneously to male Lewis rats for 6 days using Alzet minipumps. Control rats received the vehicle only. Presence of 0.1% bovine serum albumin during the isolation procedure completely removed rotenone bound ... More
Measurement of reactive oxygen species in cells and mitochondria.
AuthorsArmstrong JS, Whiteman M,
JournalMethods Cell Biol
PubMed ID17445704
This chapter discusses (1) the cellular sources of ROS and their enzymatic detoxification; (2) common methods used to determine cellular and mitochondrial ROS, including chemiluminescence (CL), spin trapping, and fluorescence and enzymatic techniques; (3) common problems associated with these assays and the interpretation of data; and (4) simple protocols for ... More
Structure and activity of the axon guidance protein MICAL.
AuthorsNadella M, Bianchet MA, Gabelli SB, Barrila J, Amzel LM
JournalProc Natl Acad Sci U S A
PubMed ID16275926
During development, neurons are guided to their targets by short- and long-range attractive and repulsive cues. MICAL, a large multidomain protein, is required for the combined action of semaphorins and plexins in axon guidance. Here, we present the structure of the N-terminal region of MICAL (MICAL(fd)) determined by x-ray diffraction ... More
Rabies virus phosphoprotein interacts with mitochondrial Complex I and induces mitochondrial dysfunction and oxidative stress.
AuthorsKammouni W, Wood H, Saleh A, Appolinario CM, Fernyhough P, Jackson AC,
Journal
PubMed ID25698500
Our previous studies in an experimental model of rabies showed neuronal process degeneration in association with severe clinical disease. Cultured adult rodent dorsal root ganglion neurons infected with challenge virus standard (CVS)-11 strain of rabies virus (RABV) showed axonal swellings and reduced axonal growth with evidence of oxidative stress. We ... More
MnSOD upregulation sustains the Warburg effect via mitochondrial ROS and AMPK-dependent signalling in cancer.
AuthorsHart PC, Mao M, de Abreu AL, Ansenberger-Fricano K, Ekoue DN, Ganini D, Kajdacsy-Balla A, Diamond AM, Minshall RD, Consolaro ME, Santos JH, Bonini MG,
Journal
PubMed ID25651975
Manganese superoxide dismutase (MnSOD/SOD2) is a mitochondria-resident enzyme that governs the types of reactive oxygen species egressing from the organelle to affect cellular signalling. Here we demonstrate that MnSOD upregulation in cancer cells establishes a steady flow of H2O2 originating from mitochondria that sustains AMP-activated kinase (AMPK) activation and the ... More
Early controlled release of peroxisome proliferator-activated receptor ß/d agonist GW501516 improves diabetic wound healing through redox modulation of wound microenvironment.
AuthorsWang X, Sng MK, Foo S, Chong HC, Lee WL, Tang MB, Ng KW, Luo B, Choong C, Wong MT, Tong BM, Chiba S, Loo SC, Zhu P, Tan NS,
Journal
PubMed ID25449811
Diabetic wounds are imbued with an early excessive and protracted reactive oxygen species production. Despite the studies supporting PPARß/d as a valuable pharmacologic wound-healing target, the therapeutic potential of PPARß/d agonist GW501516 (GW) as a wound healing drug was never investigated. Using topical application of polymer-encapsulated GW, we revealed that ... More
Proline Metabolism Increases katG Expression and Oxidative Stress Resistance in Escherichia coli.
AuthorsZhang L, Alfano JR, Becker DF,
Journal
PubMed ID25384482
The oxidation of l-proline to glutamate in Gram-negative bacteria is catalyzed by the proline utilization A (PutA) flavoenzyme, which contains proline dehydrogenase (PRODH) and ?(1)-pyrroline-5-carboxylate (P5C) dehydrogenase domains in a single polypeptide. Previous studies have suggested that aside from providing energy, proline metabolism influences oxidative stress resistance in different organisms. ... More
Topography of tyrosine residues and their involvement in peroxidation of polyunsaturated cardiolipin in cytochrome c/cardiolipin peroxidase complexes.
AuthorsKapralov AA, Yanamala N, Tyurina YY, Castro L, Samhan-Arias A, Vladimirov YA, Maeda A, Weitz AA, Peterson J, Mylnikov D, Demicheli V, Tortora V, Klein-Seetharaman J, Radi R, Kagan VE,
JournalBiochim Biophys Acta
PubMed ID21550335
Formation of cytochrome c (cyt c)/cardiolipin (CL) peroxidase complex selective toward peroxidation of polyunsaturated CLs is a pre-requisite for mitochondrial membrane permeabilization. Tyrosine residues - via the generation of tyrosyl radicals (Tyr) - are likely reactive intermediates of the peroxidase cycle leading to CL peroxidation. We used mutants of horse ... More
Studies on the photosensitized reduction of resorufin and implications for the detection of oxidative stress with Amplex Red.
AuthorsZhao B, Ranguelova K, Jiang J, Mason RP,
JournalFree Radic Biol Med
PubMed ID21419845
The photosensitized reduction of resorufin (RSF), the fluorescent product of Amplex Red, was investigated using electron spin resonance (ESR), optical absorption/fluorescence, and oxygen consumption measurements. Anaerobic reaction of RSF in the presence of the electron donor reduced nicotinamide adenine dinucleotide (NADH) demonstrated that during visible light irradiation (? > 300 ... More
Reduction of clofazimine by mycobacterial type 2 NADH:quinone oxidoreductase: a pathway for the generation of bactericidal levels of reactive oxygen species.
AuthorsYano T, Kassovska-Bratinova S, Teh JS, Winkler J, Sullivan K, Isaacs A, Schechter NM, Rubin H,
JournalJ Biol Chem
PubMed ID21193400
The mechanism of action of clofazimine (CFZ), an antimycobacterial drug with a long history, is not well understood. The present study describes a redox cycling pathway that involves the enzymatic reduction of CFZ by NDH-2, the primary respiratory chain NADH:quinone oxidoreductase of mycobacteria and nonenzymatic oxidation of reduced CFZ by ... More
FOXO3A regulates peroxiredoxin III expression in human cardiac fibroblasts.
Human cardiac fibroblasts are protected from oxidative stress triggered by inflammation after myocardial injury (Li, P. F., Dietz, R., and von Harsdorf, R. (1999) FEBS Lett. 448, 206-210) by expressing potent antioxidant defenses such as superoxide dismutases, catalases, glutathione-peroxidases, and peroxiredoxins. Recently the transcription factor FOXO3A has been shown to ... More
Comparison of fluorogenic and chromogenic assay systems in the detection of Escherichia coli O157 by a novel polymyxin-based ELISA.
AuthorsBlais BW, Leggate J, Bosley J, Martinez-Perez A,
JournalLett Appl Microbiol
PubMed ID15548304
AIMS: Different indicator enzymes and fluorogenic or chromogenic substrates were compared as detector systems in a novel polymyxin-based enzyme-linked immunosorbent assay (ELISA) for Escherichia coli O157 lipopolysaccharide (LPS) antigens. METHODS AND RESULTS: An ELISA system was developed using polymyxin immobilized in the wells of a microtitre plate as a high-affinity ... More
Reactive oxygen and targeted antioxidant administration in endothelial cell mitochondria.
AuthorsO'Malley Y, Fink BD, Ross NC, Prisinzano TE, Sivitz WI,
JournalJ Biol Chem
PubMed ID17060316
We used fluorescent probes and EPR to study the mechanism(s) underlying reactive oxygen species (ROS) production by endothelial cell mitochondria and the action of mitoquinol, a mitochondria-targeted antioxidant. ROS measured by fluorescence resulted from complex I superoxide released to the matrix and converted to H(2)O(2). In contrast, EPR largely detected ... More
Detection and measurement of reactive oxygen intermediates in mitochondria and cells.
AuthorsWhiteman M, Dogra Y, Winyard PG, Armstrong JS,
JournalMethods Mol Biol
PubMed ID19253043
Reactive oxygen intermediates (ROIs) play a key role in a number of human diseases either by inducing cell death, cellular proliferation, or by acting as mediators in cellular signaling. Therefore, their measurement in vivo and in cell culture is desirable but technically difficult and often troublesome. To address some of ... More
Thioredoxin-interacting protein mediates high glucose-induced reactive oxygen species (ROS) generation by mitochondria and the NADPH oxidase, Nox4, in mesangial cells.
AuthorsShah A, Xia L, Goldberg H, Lee KW, Quaggin SE, Fantus IG,
JournalJ Biol Chem
PubMed ID23329835
Objective: Thioredoxin-interacting protein (TxNIP) is upregulated by high glucose and is associated with oxidative stress. It has been implicated in hyperglycemia-induced beta-cell dysfunction and apoptosis. As high glucose and oxidative stress mediate diabetic nephropathy (DN), the contribution of TxNIP was investigated in renal mesangial cell reactive oxygen species (ROS) generation ... More
Yeast colony survival depends on metabolic adaptation and cell differentiation rather than on stress defense.
AuthorsCáp M, Váchová L, Palková Z,
JournalJ Biol Chem
PubMed ID19801643
Enzymes scavenging reactive oxygen species (ROS) are important for cell protection during stress and aging. A deficiency in these enzymes leads to ROS imbalance, causing various disorders in many organisms, including yeast. In contrast to liquid cultures, where fitness of the yeast population depends on its ROS scavenging capability, the ... More
Dysregulation of mitochondrial biogenesis in vascular endothelial and smooth muscle cells of aged rats.
AuthorsUngvari Z, Labinskyy N, Gupte S, Chander PN, Edwards JG, Csiszar A,
JournalAm J Physiol Heart Circ Physiol
PubMed ID18326800
Mitochondrial biogenesis is involved in the control of cell metabolism, signal transduction, and regulation of mitochondrial reactive oxygen species (ROS) production. Despite the central role of mitochondria in cellular aging and endothelial physiology, there are no studies extant investigating age-related alterations in mitochondrial biogenesis in blood vessels. Electronmicroscopy and confocal ... More
Analysis and optimization of copper-catalyzed azide-alkyne cycloaddition for bioconjugation.
AuthorsHong V, Presolski SI, Ma C, Finn MG,
JournalAngew Chem Int Ed Engl
PubMed ID19943299
Since its discovery in 2002, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction—the most widely recognized example of click chemistry—has been rapidly embraced for applications in myriad fields. The attractiveness of this procedure stems from the selective reactivity of azides and alkynes only with each other. Because of the fragile nature and ... More
Hydrogen peroxide generated extracellularly by receptor-ligand interaction facilitates cell signaling.
AuthorsDeYulia GJ, Cárcamo JM, Bórquez-Ojeda O, Shelton CC, Golde DW
JournalProc Natl Acad Sci U S A
PubMed ID15795385
Reactive oxygen species (ROS) are key components of postreceptor intracellular signaling pathways; however, the role of ROS in signal initiation is uncertain. We discovered that receptor-ligand interaction caused the generation of hydrogen peroxide (H2O2). Using members of the hematopoietin receptor superfamily, as well as EGF receptor, we show that H2O2 ... More
Hydrogen peroxide regulation of endothelial exocytosis by inhibition of N-ethylmaleimide sensitive factor.
AuthorsMatsushita K, Morrell CN, Mason RJ, Yamakuchi M, Khanday FA, Irani K, Lowenstein CJ
JournalJ Cell Biol
PubMed ID15998800
Although an excess of reactive oxygen species (ROS) can damage the vasculature, low concentrations of ROS mediate intracellular signal transduction pathways. We hypothesized that hydrogen peroxide plays a beneficial role in the vasculature by inhibiting endothelial exocytosis that would otherwise induce vascular inflammation and thrombosis. We now show that endogenous ... More
H2O2 is required for UVB-induced EGF receptor and downstream signaling pathway activation.
AuthorsPeus D, Meves A, Vasa RA, Beyerle A, O'Brien T, Pittelkow MR
JournalFree Radic Biol Med
PubMed ID10641711
Ultraviolet radiation (UVR)-induced receptor phosphorylation is increasingly recognized as a widely occurring phenomenon. However, the mechanisms, mediators, and sequence of events involved in this process remain ill-defined. We have recently shown that exposure of human keratinocytes to physiologic doses of ultraviolet B radiation (UVB) activates epidermal growth factor receptor (EGFR)/extracellular-regulated ... More
Hydrogen peroxide mediates plant root cell response to nutrient deprivation.
AuthorsShin R, Schachtman DP
JournalProc Natl Acad Sci U S A
PubMed ID15173595
Potassium (K(+)) is an essential nutrient required by plants in large quantities, but changes in soil concentrations may limit K(+) acquisition by roots. It is not known how plant root cells sense or signal the changes that occur after the onset of K(+) deficiency. Changes in the kinetics of Rb(+) ... More
Hypersensitivity to oxygen and shortened lifespan in a Drosophila mitochondrial complex II mutant.
AuthorsWalker DW, Hájek P, Muffat J, Knoepfle D, Cornelison S, Attardi G, Benzer S
JournalProc Natl Acad Sci U S A
PubMed ID17056719
Oxidative stress is implicated as a major cause of aging and age-related diseases, such as Parkinson's and Alzheimer's, as well as ischemia-reperfusion injury in stroke. The mitochondrial electron transport chain is the principal source of reactive oxygen species within cells. Despite considerable medical interest, the molecular mechanisms that regulate reactive ... More
Degradation of oxidized proteins by autophagy during oxidative stress in Arabidopsis.
AuthorsXiong Y, Contento AL, Nguyen PQ, Bassham DC
JournalPlant Physiol
PubMed ID17098847
Upon encountering oxidative stress, proteins are oxidized extensively by highly reactive and toxic reactive oxidative species, and these damaged, oxidized proteins need to be degraded rapidly and effectively. There are two major proteolytic systems for bulk degradation in eukaryotes, the proteasome and vacuolar autophagy. In mammalian cells, the 20S proteasome ... More
An immediate endothelial cell signaling response to lung ischemia.
AuthorsSong C, Al-Mehdi AB, Fisher AB
JournalAm J Physiol Lung Cell Mol Physiol
PubMed ID11557603
Abrupt cessation of lung perfusion induces a rapid endothelial response that is not associated with anoxia but reflects loss of normal shear stress. This response includes membrane depolarization, H(2)O(2) generation, and increased intracellular Ca(2+). We evaluated these parameters immediately upon nonhypoxic ischemia using fluorescence videomicroscopy to image in situ endothelial ... More
NADPH oxidase activation increases the sensitivity of intracellular Ca2+ stores to inositol 1,4,5-trisphosphate in human endothelial cells.
Many stimuli that activate the vascular NADPH oxidase generate reactive oxygen species and increase intracellular Ca(2+), but whether NADPH oxidase activation directly affects Ca(2+) signaling is unknown. NADPH stimulated the production of superoxide anion and H(2)O(2) in human aortic endothelial cells that was inhibited by the NADPH oxidase inhibitor diphenyleneiodonium ... More
Persistent nuclear factor-kappa B activation in Ucp2-/- mice leads to enhanced nitric oxide and inflammatory cytokine production.
AuthorsBai Y, Onuma H, Bai X, Medvedev AV, Misukonis M, Weinberg JB, Cao W, Robidoux J, Floering LM, Daniel KW, Collins S
JournalJ Biol Chem
PubMed ID15757894
One of the phenotypes of mice with targeted disruption of the uncoupling protein-2 gene (Ucp2-/-) is greater macrophage phagocytic activity and free radical production, resulting in a striking resistance to infectious microorganisms. In this study, the molecular mechanisms of this enhanced immune response were investigated. We found that levels of ... More
A stable nonfluorescent derivative of resorufin for the fluorometric determination of trace hydrogen peroxide: applications in detecting the activity of phagocyte NADPH oxidase and other oxidases.
AuthorsZhou M, Diwu Z, Panchuk-Voloshina N, Haugland RP
JournalAnal Biochem
PubMed ID9367498
The enzymatic determination of hydrogen peroxide can be accomplished with high sensitivity and specificity using N-acetyl-3, 7-dihydroxyphenoxazine (Amplex Red), a highly sensitive and chemically stable fluorogenic probe for the enzymatic determination of H2O2. Enzyme-catalyzed oxidation of Amplex Red, which is a colorless and nonfluorescent derivative of dihydroresorufin, produces highly fluorescent ... More
A cell-based ultra-high-throughput screening assay for identifying inhibitors of D-amino acid oxidase.
AuthorsBrandish PE, Chiu CS, Schneeweis J, Brandon NJ, Leech CL, Kornienko O, Scolnick EM, Strulovici B, Zheng W
JournalJ Biomol Screen
PubMed ID16760370
Enzymes are often considered less "druggable" targets than ligand-regulated proteins such as G-protein-coupled receptors, ion channels, or other hormone receptors. Reasons for this include cellular location (intracellular vs. cell surface), typically lower affinities for the binding of small molecules compared to ligand-specific receptors, and binding (catalytic) sites that are often ... More
Food restriction attenuates age-related increase in the sensitivity of endothelial cells to oxidized lipids.
AuthorsYang H, Shi M, Story J, Richardson A, Guo Z
JournalJ Gerontol A Biol Sci Med Sci
PubMed ID15071074
Age-related endothelial dysfunction has been suggested to play a role in atherogenesis. Food restriction (FR) has been shown to retard the development of atherosclerosis. The goal of this report is to assess the effect of aging and FR on endothelial functions, including the release of endothelial nitric oxide (NO) and ... More
Reaction progress of chromophore biogenesis in green fluorescent protein.
AuthorsZhang L, Patel HN, Lappe JW, Wachter RM
JournalJ Am Chem Soc
PubMed ID16594713
The mature form of green fluorescent protein (GFP) is generated by a spontaneous self-modification process that is essentially irreversible. A key step in chromophore biosynthesis involves slow air oxidation of an intermediate species, in which the backbone atoms of residues 65-67 have condensed to form a five-membered heterocycle. We have ... More
Inhibition of mitochondrial respiration as a source of adaphostin-induced reactive oxygen species and cytotoxicity.
AuthorsLe SB, Hailer MK, Buhrow S, Wang Q, Flatten K, Pediaditakis P, Bible KC, Lewis LD, Sausville EA, Pang YP, Ames MM, Lemasters JJ, Holmuhamedov EL, Kaufmann SH
JournalJ Biol Chem
PubMed ID17213201
Adaphostin is a dihydroquinone derivative that is undergoing extensive preclinical testing as a potential anticancer drug. Previous studies have suggested that the generation of reactive oxygen species (ROS) plays a critical role in the cytotoxicity of this agent. In this study, we investigated the source of these ROS. Consistent with ... More
Mitochondrial matrix phosphoproteome: effect of extra mitochondrial calcium.
AuthorsHopper RK, Carroll S, Aponte AM, Johnson DT, French S, Shen RF, Witzmann FA, Harris RA, Balaban RS
JournalBiochemistry
PubMed ID16489745
Post-translational modification of mitochondrial proteins by phosphorylation or dephosphorylation plays an essential role in numerous cell signaling pathways involved in regulating energy metabolism and in mitochondrion-induced apoptosis. Here we present a phosphoproteomic screen of the mitochondrial matrix proteins and begin to establish the protein phosphorylations acutely associated with calcium ions ... More
A redox-sensitive pathway mediates oxidized LDL-induced downregulation of insulin-like growth factor-1 receptor.
AuthorsHigashi Y, Peng T, Du J, Sukhanov S, Li Y, Itabe H, Parthasarathy S, Delafontaine P
JournalJ Lipid Res
PubMed ID15805544
Oxidized low density lipoprotein (OxLDL) has multiple proatherogenic effects, including induction of apoptosis. We have recently shown that OxLDL markedly downregulates insulin-like growth factor-1 receptor (IGF-1R) in human aortic smooth muscle cells, and that IGF-1R overexpression blocks OxLDL-induced apoptosis. We hypothesized that specific OxLDL-triggered signaling events led to IGF-1R downregulation ... More
Motexafin gadolinium, a tumor-selective drug targeting thioredoxin reductase and ribonucleotide reductase.
AuthorsHashemy SI, Ungerstedt JS, Zahedi Avval F, Holmgren A
JournalJ Biol Chem
PubMed ID16481328
Motexafin gadolinium (MGd) is a chemotherapeutic drug that selectively targets tumor cells and mediates redox reactions generating reactive oxygen species. Thioredoxin (Trx), NADPH, and thioredoxin reductase (TrxR) of the cytosol/nucleus or mitochondria are major thiol-dependent reductases with many functions in cell growth, defense against oxidative stress, and apoptosis. Mammalian TrxRs ... More
Iron detoxification properties of Escherichia coli bacterioferritin. Attenuation of oxyradical chemistry.
AuthorsBou-Abdallah F, Lewin AC, Le Brun NE, Moore GR, Chasteen ND
JournalJ Biol Chem
PubMed ID12124394
Bacterioferritin (EcBFR) of Escherichia coli is an iron-mineralizing hemoprotein composed of 24 identical subunits, each containing a dinuclear metal-binding site known as the "ferroxidase center." The chemistry of Fe(II) binding and oxidation and Fe(III) hydrolysis using H(2)O(2) as oxidant was studied by electrode oximetry, pH-stat, UV-visible spectrophotometry, and electron paramagnetic ... More
Hydrogen peroxide formation during iron deposition in horse spleen ferritin using O2 as an oxidant.
AuthorsLindsay S, Brosnahan D, Watt GD
JournalBiochemistry
PubMed ID11258954
The reaction of Fe2+ with O2 in the presence of horse spleen ferritin (HoSF) results in deposition of FeOH3 into the hollow interior of HoSF. This reaction was examined at low Fe2+/HoSF ratios (5-100) under saturating air at pH 6.5-8.0 to determine if H2O2 is a product of the iron ... More
Stereospecificity and kinetic mechanism of human prenylcysteine lyase, an unusual thioether oxidase.
AuthorsDigits JA, Pyun HJ, Coates RM, Casey PJ
JournalJ Biol Chem
PubMed ID12186880
Prenylated proteins contain either a 15-carbon farnesyl or a 20-carbon geranylgeranyl isoprenoid covalently attached to cysteine residues at or near their C terminus. The cellular abundance of prenylated proteins, as well as the stability of the thioether bond, poses a metabolic challenge to cells. A lysosomal enzyme termed prenylcysteine lyase ... More
cAMP-response element-binding protein mediates acid-induced NADPH oxidase NOX5-S expression in Barrett esophageal adenocarcinoma cells.
AuthorsFu X, Beer DG, Behar J, Wands J, Lambeth D, Cao W
JournalJ Biol Chem
PubMed ID16707484
Gastroesophageal reflux disease complicated by Barrett esophagus (BE) is a major risk factor for esophageal adenocarcinoma (EA). The mechanisms whereby acid reflux may accelerate the progression from BE to EA are not known. We found that NOX1 and NOX5-S were the major isoforms of NADPH oxidase in SEG1-EA cells. The ... More