Agnieszka Grzelak

Publications (14)37.15 Total impact

• Article: The effects of superoxide dismutase knockout on the oxidative stress parameters and survival of mouse erythrocyt

  Agnieszka Grzelak, Marcin Kruszewski, Ewa Macierzyńska, Łukasz Piotrowski, Łukasz Pułaski, Błażej Rychlik, Grzegorz Bartosz
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  ABSTRACT: The erythrocytes of 12-month old Sod1 −/− mice showed an increased level of reactive oxygen species (ROS), as estimated by the degree of dihydroethidine and dihydrorhodamine oxidation, and the increased level of Heinz bodies. No indices of severe oxidative stress were found in the red blood cells and blood plasma of Sod1 −/− mice as judged from the lack of significant changes in the levels of erythrocyte and plasma glutathione, plasma protein thiol and carbonyl groups and thiobarbituric-acid reactive substances in the blood plasma. However, a decreased erythrocyte lifespan, increased reticulocyte count and splenomegaly were noted, indicating the importance of superoxide dismutase for maintaining erythrocyte viability. The levels of erythrocyte ROS and Heinz bodies and the reticulocyte count were indistinguishable in Sod1 +/+ and Sod1 +/− mice, suggesting that a superoxide dismutase activity decrease to half of its normal value may be sufficient to secure the protective effects of the enzyme.
  Cellular & Molecular Biology Letters 04/2012; 14(1):23-34. · 1.50 Impact Factor
• Source

  Available from: PubMed Central

  Article: A genetic analysis of nitric oxide-mediated signaling during chronological aging in the yeast.

  Anna Lewinska, Ewa Macierzynska, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: In mammals, NO(•), a signaling molecule is implicated in the regulation of vasodilation, neurotransmission and immune response. It is believed that NO(•) is a signaling molecule also in unicellular organism like yeast and may be involved in the regulation of apoptosis and sporulation. It has been reported that NO(•) is produced during chronological aging (CA) leading to an increase of the superoxide level, which in turn mediates apoptosis. Since this conclusion was based on indirect measurements of NO(•) by the Griess reaction, the role of NO(•) signaling during CA in the yeast remains uncertain. We investigated this issue more precisely using different genetic and biochemical methodologies. We used cells lacking the factors influencing nitrosative stress response like flavohemoglobin metabolizing NO(•), S-nitrosoglutathione reductase metabolizing S-nitrosoglutathione and the transcription factor Fzf1p mediating NO(•) response. We measured the standard parameters describing CA and found an elevation in the superoxide level, percentage of death cells, the level of TUNEL positive cells and a decrease in proliferating potential. These observations showed no significant differences between wild type cells and the disruptants except for a small elevation of the superoxide level in the Δsfa1 mutant. The intracellular NO(•) level and flavohemoglobin expression decreased rather than increased during CA. Products of general nitrogen metabolism and protein tyrosine nitration were slightly decreased during CA, the magnitude of changes showing no differences between the wild type and the mutant yeast. Altogether, our data indicate that apoptosis during yeast CA is mediated by superoxide signaling rather than NO(•) signaling.
  Biogerontology 03/2011; 12(4):309-20. · 3.34 Impact Factor
• Article: Nucleolus as an oxidative stress sensor in the yeast Saccharomyces cerevisiae.

  Anna Lewinska, Maciej Wnuk, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: In mammals, the nucleolus is thought to be a stress sensor; upon cellular stress conditions, a release of nucleolar proteins and down-regulation of rDNA transcription occurs. Since yeast Rrn3p is a homolog of the mammalian RNA polymerase I (Pol I)-specific transcription factor TIF-IA, we decided to investigate the role of Rrn3p in oxidant-induced nucleolar stress in yeast. We show that, after oxidant treatment, the level of Rrn3p is unaffected but Rrn3p is translocated from the nucleolus into the cytoplasm and a point mutation in the RRN3 gene leads to hypersensitivity of the yeast to oxidants. This hypersensitivity can be abolished by re-introduction of the active RRN3 gene, antioxidant supplementation and anoxic atmosphere. Additionally, we employed the PRINS technique to monitor oxidant-mediated changes in the nucleolar structure. Taken together, our results suggest the role of the yeast nucleolus in the response to oxidative stress signals.
  Redox report: communications in free radical research 01/2010; 15(2):87-96. · 1.51 Impact Factor
• Article: Magnesium content, total antioxidant status and lipid peroxidation in rainbow trout (Oncorhynchus mykiss Walbaum).

  Ewa Brucka-Jastrzebska, Dorota Kawczuga, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: The present study was aimed at evaluating magnesium content, ferric reducing antioxidant power (FRAP) and lipid peroxidation in selected tissues of rainbow trout during their development. For mineral and biochemical assay, samples of liver, kidney, gills and blood were taken from fish. Magnesium concentration ranged between 35.5 and 249.2 mg·kg⁻¹ wt/wt. Most magnesium was found in the gills and the less in kidneys. FRAP values in the examined fish varied from 0.85 to 4.64 nmol Trolox Eq.mg⁻¹ protein. The highest FRAP was observed in the kidneys and the lowest in the gills. Concentration of malondialdehyde (MDA) in the examined tissue homogenates averaged 4.16-11.36 nmol·mg⁻¹ protein. We observed that levels of analyzed parameters increased during growth of the fish.
  Magnesium research: official organ of the International Society for the Development of Research on Magnesium 12/2009; 22(4):273-9. · 1.52 Impact Factor
• Article: The effects of superoxide dismutase knockout on the oxidative stress parameters and survival of mouse erythrocytes.

  Agnieszka Grzelak, Marcin Kruszewski, Ewa Macierzyńska, Łukasz Piotrowski, Łukasz Pułaski, Błazej Rychlik, Grzegorz Bartosz
  [show abstract] [hide abstract]
  ABSTRACT: The erythrocytes of 12-month old Sod1 (-/-) mice showed an increased level of reactive oxygen species (ROS), as estimated by the degree of dihydroethidine and dihydrorhodamine oxidation, and the increased level of Heinz bodies. No indices of severe oxidative stress were found in the red blood cells and blood plasma of Sod1 (-/-) mice as judged from the lack of significant changes in the levels of erythrocyte and plasma glutathione, plasma protein thiol and carbonyl groups and thiobarbituric-acid reactive substances in the blood plasma. However, a decreased erythrocyte lifespan, increased reticulocyte count and splenomegaly were noted, indicating the importance of superoxide dismutase for maintaining erythrocyte viability. The levels of erythrocyte ROS and Heinz bodies and the reticulocyte count were indistinguishable in Sod1 (+/+) and Sod1 (+/-) mice, suggesting that a superoxide dismutase activity decrease to half of its normal value may be sufficient to secure the protective effects of the enzyme.
  Cellular & Molecular Biology Letters 11/2008; 14(1):23-34. · 1.50 Impact Factor
• Article: Interaction between antioxidants in assays of total antioxidant capacity.

  Andrzej Błauz, Tomasz Pilaszek, Agnieszka Grzelak, Agata Dragan, Grzegorz Bartosz
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  ABSTRACT: Sub-additivity of antioxidant activities in assays of total antioxidant capacity has been reported previously and ascribed to binding of low-molecular weight antioxidants such as flavonoids by proteins. We demonstrate that this phenomenon is much more common and concerns also interactions between typical low-molecular weight oxidants in the assays of ABTS- decolorization and protection of fluorescein from AAPH-induced bleaching. The subadditive interactions between antioxidants may affect quantitative considerations drawn from in vitro assays of antioxidant capacity of biological samples.
  Food and Chemical Toxicology 08/2008; 46(7):2365-8. · 3.00 Impact Factor
• Article: Application of a YHB1-GFP reporter to detect nitrosative stress in yeast.

  Anna Lewinska, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: Yeast flavohemoglobin (Yhb1p) plays a pivotal role in NO(*) detoxification and has also been implicated in oxidative/reductive stress responses. In this study, we have used a YHB1-GFP reporter expressing a full-length chromosome-tagged Yhb1-GFP fusion protein to monitor changes in flavohemoglobin levels after cell treatment with oxidants, antioxidants and nitric oxide donors. Only nitric oxide donors were found to induce a dose-dependent increase in Yhb1-GFP expression while hydrogen peroxide, menadione and diamide caused a moderate diminution of YHB1-GFP fluorescence. Additionally, the levels of endogenous and hydroperoxide-induced ROS production in the Deltayhb1 mutant were comparable to those in the isogenic wild-type strain. Although peroxides increased NO(*) generation while nitrite and nitric oxide donors augmented ROS levels in yeast cells, their effects were generally not more pronounced in Deltayhb1 than in wild-type cells. Taken together, these data suggest that yeast flavohemoglobin does not contribute to cross-protection against oxidative and nitrosative stress.
  Redox report: communications in free radical research 01/2008; 13(4):161-71. · 1.51 Impact Factor
• Article: The effect of growth medium on the antioxidant defense of Saccharomyces cerevisiae.

  Ewa Macierzyńska, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: We compared the oxidation of dihydrorhodamine 123, glutathione contents and activities of superoxide dismutase (SOD) and catalase for three wild-type strains of Saccharomyces cerevisiae grown on media with different carbon sources. The rate of oxidation of dihydrorhodamine 123 was much higher in respiring cells grown on ethanol or glycerol media than in fermenting cells grown on glucose medium. The total SOD activity was highest on glycerol medium and lowest on ethanol medium, while the catalase activity was highest on glycerol medium. The sequence of glutathione content values was: glucose > ethanol > glycerol.
  Cellular & Molecular Biology Letters 05/2007; 12(3):448-56. · 1.50 Impact Factor
• Article: Accumulation of oxidative damage during replicative aging of the yeast Saccharomyces cerevisiae.

  Agnieszka Grzelak, Ewa Macierzyńska, Grzegorz Bartosz
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  ABSTRACT: Comparison of senescent yeast obtained by the "baby machine" technique with 2-day-old stationary phase cells revealed decreased activities of glutathione reductase, glutathione S-transferase, glutathione peroxidase and alcohol dehydrogenase, reduction of total antioxidant capacity, protein glycation and accumulation of products of oxidative damage: protein carbonyls and DNA damage assessed by augmented content of 8-oxoguanine and increased tail momentum of cellular DNA in the comet assay. These results are consistent with a role for oxidative damage during replicative senescence of Saccharomyces cerevisiae.
  Experimental Gerontology 10/2006; 41(9):813-8. · 3.74 Impact Factor
• Article: Melatonin does not react rapidly with hydrogen peroxide.

  Agnieszka Grzelak, Ewa Macierzyńska, Grzegorz Bartosz
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  ABSTRACT: It has been claimed that melatonin reacts directly with hydrogen peroxide with a very high rate constant (2.5 x 10(5)-2.3 x 10(6) M(-1) s(-1)) Both these values were derived from inhibition by melatonin of peroxidase-catalyzed oxidation of Phenol Red by hydrogen peroxide, assuming that this inhibition is due to direct scavenging of hydrogen peroxide by melatonin. In this study, we show that this reasoning is illegitimate and melatonin decreases the yield of oxidation of Phenol Red as a competitive substrate. Monitoring changes of concentration of hydrogen peroxide incubated with melatonin using Xylenol Orange points to poor reactivity of melatonin with H2O2.
  Free Radical Research 12/2004; 38(11):1155-8. · 2.88 Impact Factor
• Article: Pro-oxidative effects of Tempo in systems containing oxidants.

  Aneta Balcerczyk, Agnieszka Grzelak, Miroslaw Soszynski, Grzegorz Bartosz
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  ABSTRACT: 2,2,6,6-Tetramethylpiperidine-1-oxyl (Tempo), previously reported by us to augment oxidation of glutathione induced by peroxynitrite (Glebska J, Skolimowski J, Kudzin Z, Gwozdzinski K, Grzelak A, Bartosz G. Pro-oxidative activity of nitroxides in their reactions with glutathione. Free Radic Biol Med 2003; 35: 310-316) was found to increase oxidation of glutathione induced by various oxidants, including persulfate, tert-butyl hydroperoxide and hydrogen peroxide. Tempo augmented also the inactivation and thiol loss of alcohol dehydrogenase induced by 2,2'-azobis(2-amidinopropane) (AAPH) and oxidative degradation of deoxyribose induced by ammonium persulfate and tert-butyl hydroperoxide. These results point to a pro-oxidative effect of nitroxides on a range of biomolecules subjected to the action of various oxidants.
  Redox Report 02/2004; 9(3):153-9. · 1.73 Impact Factor
• Article: Pro-oxidative activity of nitroxides in their reactions with glutathione.

  Jolanta Głebska, Janusz Skolimowski, Zbigniew Kudzin, Krzysztof Gwoździński, Agnieszka Grzelak, Grzegorz Bartosz
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  ABSTRACT: Nitroxides are unreactive towards glutathione in vitro. Interaction of nitroxides with peroxynitrite does not lead to a significant loss of their electron paramagnetic resonance (EPR) signal. However, addition of peroxynitrite to a solution containing glutathione and nitroxides induces an irreversible disappearance of EPR signal of nitroxides and augmentation of glutathione oxidation which is a pro-oxidant effect of these compounds. Nitroxide loss leading to the formation of amine derivatives is initiated by products of glutathione oxidation by peroxynitrite. The pro-oxidant action of nitroxides at micromolar concentrations may be important in view of the proposed use of these compounds as antioxidants.
  Free Radical Biology and Medicine 09/2003; 35(3):310-6. · 5.42 Impact Factor
• Article: EDTA loses its antioxidant properties upon storage in buffer.

  Jolanta Głebska, Agnieszka Grzelak, Łukasz Pułaski, Grzegorz Bartosz
  Analytical Biochemistry 01/2003; 311(1):87-9. · 3.00 Impact Factor
• Article: Hemoglobin can nitrate itself and other proteins

  Agnieszka Grzelak, Aneta Balcerczyk, Agnieszka Mateja, Grzegorz Bartosz
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  ABSTRACT: Incubation of human hemoglobin with nitrite and hydrogen peroxide was found to induce autonitration and nitration of another protein (bovine serum albumin), as demonstrated by detection of nitrotyrosine residues in Western blots of separated membrane proteins. Inhibition of nitration by conversion of hemoglobin into the cyanmet form demonstrates that nitration is due to the pseudoperoxidase activity of hemoglobin. Incubation of whole erythrocytes with nitrite and hydrogen peroxide induces nitration of erythrocyte membrane proteins, much stronger when cellular catalase was inhibited with azide. These results suggest that hemoglobin and other hemoproteins may contribute to the tyrosine nitration in vivo.
  Biochimica et Biophysica Acta (BBA) - General Subjects 1528:97-100. · 5.00 Impact Factor