Biomedical subjects

M R Ciriolo

Publications and source records attributed to M R Ciriolo.

At least 19 recordsLinked to original sources

PubMed1992

Glutathione inhibits replication and expression of viral proteins in cultured cells infected with Sendai virus.

Addition of reduced glutathione inhibited the production of Sendai virus in African green monkey kidney (AGMK) cells. This result could be accounted for by a direct action of GSH on viral replication. The inhibitory action was associated to an increase of the GSH intracellular level, while the host cell metabolism was unaffected. The antiviral effect was related to decrease and inactivation of the hemagglutinin-neuraminidase (HN) virus glycoprotein.

Animals↗

PubMed1992

NGF restores decrease in catalase activity and increases superoxide dismutase and glutathione peroxidase activity in the brain of aged rats.

The effects of ageing on the activity of copper-zinc superoxide dismutase (SOD), selenium-dependent and independent glutathione peroxidase (GSH-Px) and catalase in several areas of the brain in 3-, 12-, and 24-month-old rats were studied. In addition, the effects of a subacute intracerebroventricular treatment of NGF (1 microgram daily for 28 consecutive days) on SOD, GSH-Px, and catalase activity in the same areas of the brain were assessed. The effects of ageing on the activities of antioxidant enzymes varied considerably in the different brain areas studied. Copper-zinc SOD was alone in being unaffected by ageing. Intraventricular infusion of NGF significantly increased SOD activity in the prefrontal cortex, hypothalamus, caudate nucleus, and mesencephalon of 24-month-old rats. Selenium-dependent GSH-Px activity did not significantly change in 12-month-old rats but it increased in the lower brain stem of 24-month-old animals. In comparison to vehicle-treated rats, NGF significantly increased selenium-dependent GSH-Px activity in all brain areas studied in 12- and 24-month-old rats. Catalase activity decreased significantly in the majority of the brain areas studied in 12- and 24-month-old rats. NGF completely restored the fall in catalase activity in 12- and 24-month-old animals to levels similar to those occurring in young rats. In conclusion, the present experiments show, for the first time, that long-term intraventricular administration of NGF significantly increases in old animals the activity of key enzymes involved in the metabolic degradation of superoxide radicals and hydrogen peroxide.

Aging↗

PubMed1991

Age-related changes in Cu,Zn superoxide dismutase, Se-dependent and -independent glutathione peroxidase and catalase activities in specific areas of rat brain.

Oxidative injury of tissues involves both accumulation of damage due to persistent oxidative stress and loss of the proper balance of antioxidative enzymes. These events may produce a faster rate of tissue senescence. In this regard, we have assayed the antioxidative enzyme activities (Cu,Zn superoxide dismutase, glutathione peroxidase and catalase), in various areas of rat brain (prefrontal cortex, parietal cortex, hippocampus, hypothalamus, caudate nucleus, mesencephalon and lower brain stem) for the age groups of 3, 6, 12, 24 months. The results obtained show that the levels of antioxidant enzyme activities differed considerably in the various brain parts studied. Furthermore, changes in the specific activities of superoxide dismutase, catalase, and glutathione peroxidase did not follow the same pattern as a function of aging. In particular, in prefrontal cortex and caudate nucleus, superoxide dismutase and glutathione peroxidase activities did not change, while catalase activity decreased. In parietal cortex and mesencephalon, superoxide dismutase and glutathione peroxidase activities increased, but the catalase activity decreased in parietal cortex and did not change in mesencephalon. In lower brain stem, the activities of glutathione peroxidase and catalase decreased in 3-12-month-old rats. The activity of glutathione peroxidase was increased in the hippocampus and was decreased in hypothalamus during aging. In this area the catalase activity was also significantly diminished.

Aging↗

PubMed1991

Increase of Cu,Zn-superoxide dismutase activity during differentiation of human K562 cells involves activation by copper of a constantly expressed copper-deficient protein.

Cu,Zn-superoxide dismutase activity, expressed on the basis of cell number, increased by 50% during sodium butyrate-induced differentiation of human K562 erythroleukemia cells. The increased enzyme activity was found to be concomitant with constant Cu,Zn-superoxide dismutase mRNA and immunoreactive protein levels and was accompanied by a rise in intracellular copper and glutathione. Incubation of K562 cell homogenates with copper caused an increase of Cu,Zn-superoxide dismutase activity which reached the levels observed after differentiation in the presence of sodium butyrate. The same treatment led to no significant activity increase in homogenates derived from differentiated cells. Externally added ceruloplasmin increased both intracellular copper levels and Cu,Zn-superoxide dismutase activity in undifferentiated cells to a level comparable with that observed after induction of differentiation. Both increments were abolished by depletion of cell glutathione. Cu,Zn-superoxide dismutase purified from control cells had both a lower kcat and a lower copper content than the enzyme purified from differentiated cells. From these data we conclude that: 1) Cu,Zn-superoxide dismutase is present in K562 cells also under the form of a less active copper-deficient enzyme, 2) the extent of enzyme activation is regulated post-translationally by differential delivery of copper as a function of differentiation stage, and 3) glutathione is likely to play a role in delivering copper to the copper-deficient protein in intact K562 cells.

Catalase↗

PubMed1991

NGF restores decrease in catalase and increases glutathione peroxidase activity in the brain of aged rats.

The effects of subchronic administration of nerve growth factor (NGF) into the lateral ventricle on catalase and selenium-dependent glutathione-peroxidase (GSH-Px) activity in several areas of the brain in 3-, 12- and 24-month-old rats were studied. NGF given daily (1 microgram for 28 consecutive days) produced in all brain areas studied a significant increase in catalase activity in 12- and 24-month-old rats. The most important finding was a complete restoration in 12- and 24-month-old rats of catalase activity to levels similar to those occurring in young (3-month-old) rats. In addition, NGF produced in comparison to 3-month-old rats and to same age vehicle-treated rats a significant increase in selenium-dependent GSH-Px in all the brain areas studied in 12- and 24-month-old animals, whereas selenium-independent GSH-Px was unaffected. In conclusion, the present results show that long-term administration of NGF into the lateral ventricle significantly increases in old animals the activity of key enzymes involved in the metabolic degradation of hydrogen peroxide.

Aging↗

PubMed1991

Activation and induction by copper of Cu/Zn superoxide dismutase in Saccharomyces cerevisiae. Presence of an inactive proenzyme in anaerobic yeast.

The Cu/Zn superoxide dismutase activity of Saccharomyces cerevisiae was found to be strictly related to the extent of oxygen metabolism, since cells grown under anaerobic or repressed conditions were found to contain 10% and 40% the activity of derepressed cells, respectively. The dependence of Cu/Zn superoxide dismutase on oxygen was found to be related to the availability of copper to the cells since the enzyme activity and immunoreactive protein measured under the various conditions was roughly proportional to the copper content of cells and in anaerobic cells a large fraction of the enzyme was found to be in the form of an inactive proenzyme which was activated by the addition of copper to cell extracts. The Cu/Zn superoxide dismutase mRNA did not parallel the dependence of the enzyme concentration on oxygen metabolism, suggesting that the gene expression was affected by copper also at the post-transcriptional level. However, under conditions of copper overloading, a more direct effect on transcription was observed and the presence of the inactive proenzyme in anaerobic cultures was associated with the over-expression of metallothionein.

Copper↗

PubMed1991

Evidence for co-regulation of Cu,Zn superoxide dismutase and metallothionein gene expression in yeast through transcriptional control by copper via the ACE 1 factor.

Saccharomyces cerevisiae mutant strain DTY26, lacking ACE1, the protein mediator for the induction of metallothionein gene expression, is unable to increase Cu,Zn superoxide dismutase mRNA in response to copper. In the wild-type strain DTY22 transcription of both Cu,Zn superoxide dismutase and metallothionein genes is induced by copper and silver, as expected on the basis of previous results indicating that ACE1 binds only Ag(I) besides Cu(I). We conclude that at the transcriptional level Cu,ZnSOD is co-regulated with metallothionein. Furthermore, structural similarities between the two promoters were found, which could explain the co-regulation effect and the quantitative differences in the response of the two genes to copper.

Base Sequence↗

PubMed1991

Intra-nigral infusion of Cu-free superoxide dismutase prevents paraquat-induced behavioural stimulation and ECoG epileptogenic discharges in rats.

In adult rats, with cannulae chronically implanted by a stereotactic instrument into the substantia nigra (pars compacta), the electrocortical (ECoG) and behavioural effects elicited by intranigral infusion of paraquat and the prevention of these effects by prior administration into the same site of different types of superoxide dismutase, were studied. Paraquat (50 micrograms) produced an intense pattern of behavioural stimulation, contralateral circling and repetitive discharges of high voltage ECoG spikes. The effects of paraquat were abolished in all of the animals pretreated into the same site with copper-free superoxide dismutase. Pretreatment with native Cu, Zn-superoxide dismutase prolonged significantly the latency of onset but did not prevent the behavioural stimulation and ECoG spikes evoked by paraquat. On the contrary, pretreatment with albumin or saline did not confer any protection against the neurotoxicological changes induced by paraquat. In conclusion, the present experiments showed that motor, ECoG and lethal effects of paraquat were completely prevented by Cu-free superoxide dismutase, suggesting that the central effects of this herbicide are in some way related to the release in the brain of copper and/or other transition metal ions.

Animals↗

PubMed1990

Reconstitution of Cu,Zn-superoxide dismutase by the Cu(I).glutathione complex.

The reconstitution of Cu,Zn-superoxide dismutase from the copper-free protein by the Cu(I).GSH complex was monitored by: (a) EPR and optical spectroscopy upon reoxidation of the enzyme-bound copper; (b) NMR spectroscopy following the broadening of the resonances of the Cu(I).GSH complex after addition of Cu-free,Zn-superoxide dismutase; and (c) NMR spectroscopy of the Cu-free,Co(II) enzyme following the appearance of the isotropically shifted resonances of the Cu(I), Co enzyme, Cu(I).GSH was found to be a very stable complex in the presence of oxygen and a more efficient copper donor to the copper-free enzyme than other low molecular weight Cu(II) complexes. In particular, 100% reconstitution was obtained with stoichiometric copper at any GSH:copper ratio between 2 and 500. Evidence was obtained for the occurrence of a Cu(I).GSH.protein intermediate in the reconstitution process. In view of the inability of copper-thionein to reconstitute Cu,Zn-superoxide dismutase and of the detection of copper.GSH complexes in copper-over-loaded hepatoma cells (Freedman, J.H., Ciriolo, M.R., and Peisach, J. (1989) J. Biol. Chem. 264, 5598-5605), Cu(I).GSH is proposed as a likely candidate for copper donation to Cu-free,Zn-superoxide dismutase in vivo.

Animals↗

PubMed1990

Assignment of imidazole resonances from two-dimensional proton NMR spectra of bovine Cu,Zn superoxide dismutase. Evidence for similar active site conformation in the oxidized and reduced enzyme.

Two-dimensional 1H-NMR spectra were carried out on bovine Cu(I),Zn superoxide dismutase. The ring protons of the single tyrosine and of the 4 phenylalanines were identified from COSY spectra. From NOESY spectra all imidazole C-resonances could be specifically assigned to each of the 8 histidines using the crystal coordinates of the Cu(II),Zn enzyme. Since 6 histidines are involved in the structure of the active site, this result implies nearly identical active site conformations for the two oxidation states of the catalytic cycle of this enzyme, in line with its diffusion-limited rate.

Animals↗

PubMed1990

A study of the intracellular effects of glutathione by 1H-spin echo NMR of intact human erythrocytes.

The effect of adding either reduced (GSH) or oxidized (GSSG) glutathione to intact human erythrocytes was investigated by 1H-spin echo NMR, which allows direct observation of relatively concentrated low molecular weight compounds within intact cells. A specific region of the spectrum was affected by addition of GSH, with the appearance of new peaks that were diagnostic of an increase of intracellular GSH. These changes did not occur in hemolysates, and did not involve extra-cytosol GSH either free or membrane-bound. These results indicate that the intracellular redox balance of glutathione is shifted toward the reduced state by exogenous glutathione, possibly via a signal transferring system of the cell membrane.

Erythrocytes↗

PubMed1989

The role of glutathione in copper metabolism and toxicity.

Cellular copper metabolism and the mechanism of resistance to copper toxicity were investigated using a wild type hepatoma cell line (HAC) and a copper-resistant cell line (HAC600) that accumulates copper and has a highly elevated level of metallothionein (MT). Of the enzymes involved in reactive oxygen metabolism, only glutathionine peroxidase was elevated (3-4-fold) in resistant cells, suggestive of an increase in the cellular flux of hydrogen peroxide. A majority of the cytoplasmic copper (greater than 60%) was isolated from both cell lines as a GSH complex. Kinetic studies of 67Cu uptake showed that GSH bound 67Cu before the metal was complexed by MT. Depletion of cellular GSH with buthionine sulfoximine inhibited the incorporation of 67Cu into MT by greater than 50%. These results support a model of copper metabolism in which the metal is complexed by GSH soon after entering the cell. The complexed metal is then transferred to MT where it is stored. This study also indicates that resistance to metal toxicity in copper-resistant hepatoma cells is due to increases in both cellular GSH and MT. Furthermore, it is suggested that elevated levels of GSH peroxidase allows cells to more efficiently accommodate an increased cellular hydrogen peroxide flux that may occur as a consequence of elevated levels of cytoplasmic copper.

Animals↗

PubMed1989

A comparative study of the interactions of bleomycin with nuclei and purified DNA.

Fe(III)-bleomycin associates strongly with rat liver nuclei and binds to nuclear DNA. Metal-free and Cu(II)-bleomycin, however, do not bind to nuclei. The treatment of nuclei with activated iron-bleomycin results in nucleic base and base propenal release from the DNA, and also gives membrane peroxidation. Isolation and quantitation of the base propenals and free bases released subsequent to activated bleomycin treatment reveal an alteration in the stoichiometry of these products compared to those released from purified DNA. With nuclei, significantly less propenal is formed, although the yield of free base is equivalent to that from purified DNA. The membrane peroxidation products from nuclei are the same as those obtained from microsomal membranes treated with activated bleomycin. Superoxide dismutase inhibits the membrane peroxidation but has no effect on the DNA breakage reactions. The results implicate a role for iron in mediating the in vivo action of bleomycin and also reveal a potentially toxic effect, membrane peroxidation, separate from DNA damage.

Animals↗

PubMed1989

Transfer RNA is cleaved by activated bleomycin.

Activated bleomycin is shown for the first time to cleave tRNA in a specific and dose-dependent manner. Adenine and uracil are released in the reaction. Bleomycin and Fe(III)-bleomycin bind to yeast tRNAPhe) in analogy with the known behavior of the drug with B-DNA.

Bleomycin↗

PubMed1987

Microsome-stimulated activation of ferrous bleomycin in the presence of DNA.

The inhibition of Fe(II)-bleomycin activation, by a large excess of DNA, is overcome by rat liver microsomes in the presence of NADPH. This release of inhibition, as indicated by increased yields of base propenal from DNA scission, is enhanced by menadione, is inhibited by superoxide dismutase, and is therefore dependent on superoxide anion. Microsomal activation of Fe(II)-bleomycin doubles the stoichiometry of base propenal yield compared to that obtained upon self-activation of the drug; 0.5 mol of base propenal is formed and 0.5 mol of NADPH is oxidized per mol of Fe(II)-bleomycin. In the presence of a large excess of DNA, Cu(II)-bleomycin is not reduced and Fe(III)-bleomycin is neither reduced nor activated by microsomes in cases where activation of Fe(II)-bleomycin is maximal. We suggest that in vivo, electron transport enzymes at or near the nucleus can stimulate the activation of Fe(II)-bleomycin under conditions where self-activation does not readily occur.

Animals↗

PubMed1986

Effect of the redox state of the red blood cell components on the inactivation of glutathione peroxidase by divicine.

The redox state of red blood cell components was found to have profound effects on the specific inactivation of erythrocyte glutathione (GSH) peroxidase by divicine, a hydroquinone imine molecule of fava beans likely to be responsible, through redox cycling, of the oxidative damage of red blood cells ultimately resulting in the hemolysis of favism. Oxidation of hemoglobin is a necessary step for the inactivation to take place, apparently as a H2O2-MetHb adduct. On the other hand, the presence of either reduced NADP or glutathione enhances the inactivating effect although NADPH inhibits the oxidation of hemoglobin, and this suggests a catalytic role for MetHb in the inactivation process.

Ascorbic Acid↗

PubMed1985

Inactivation of red cell glutathione peroxidase by divicine and its relation to the hemolysis of favism.

A significant inactivation of red blood cell glutathione peroxidase (25% less than the physiological value) was observed after exposure of intact erythrocytes to 2 mM divicine (an autoxidizable aminophenol from Vicia faba seeds) and 2 mM ascorbate for 3 h at 37 degrees C. Addition of catalase and conversion of Hb to the carbomonoxy derivative resulted in protection against enzyme inactivation. Oxidation of Hb was a concurrent phenomenon, and augmented the inactivating effect. In hemolysates, much stronger effects were observed at shorter times (2 h); divicine was effective also without ascorbate, and the presence of reductants (ascorbate or glutathione or NADPH) enhanced its inactivating power. Of the other antioxidant enzymes, superoxide dismutase was unaffected under the same experimental conditions. Catalase was found to be much less sensitive to the inactivation; it was almost unaffected in experiments with intact erythrocytes and specifically protected by NADPH in experiments with hemolysates. This specific damage of glutathione peroxidase, apparently involving interaction of H2O2 and HbO2, may be related to the pathogenesis of hemolysis in favism.

Adult↗

PubMed1985

11p13 deletion and reduced RBC catalase in a patient with aniridia, glaucoma and bilateral Wilms' tumor.

A rare case of a one-year-old child with Wilms' tumor, aniridia and glaucoma is described, in whom bone marrow chromosome analysis showed the presence of an interstitial microdeletion on the short arm of chromosome 11, presumably involving the p13 band. Research of the enzyme activity of RBC catalase showed a 40% reduction. This finding is compatible with the loss of the 11p13 band which contains the gene coding this enzyme. 11p13 deletion in Wilms' tumor and 13q interstitial deletion in retinoblastoma provide a rare case of prezygotic chromosome abnormality, which may be considered to have a determinant role in the tumor etiopathogenesis.

Catalase↗