Sample records for n-acetylcysteine-mediated catalase upregulation

  1. Catalase activity prevents exercise-induced up-regulation of vasoprotective proteins in venous tissue

    PubMed Central

    Dao, Vu Thao-Vi; Floeren, Melanie; Kumpf, Stephanie; Both, Charlotte; Peter, Bärbel; Balz, Vera; Suvorava, Tatsiana; Kojda, Georg

    2011-01-01

    Abstract Physical activity induces favourable changes of arterial gene expression and protein activity, although little is known about its effect in venous tissue. Although our understanding of the initiating molecular signals is still incomplete, increased expression of endothelial nitric oxide synthase (eNOS) is considered a key event. This study sought to investigate the effects of two different training protocols on the expression of eNOS and extracellular superoxide dismutase (ecSOD) in venous and lung tissue and to evaluate the underlying molecular mechanisms. C57Bl/6 mice underwent voluntary exercise or forced physical activity. Changes of vascular mRNA and protein levels and activity of eNOS, ecSOD and catalase were determined in aorta, heart, lung and vena cava. Both training protocols similarly increased relative heart weight and resulted in up-regulation of aortic and myocardial eNOS. In striking contrast, eNOS expression in vena cava and lung remained unchanged. Likewise, exercise up-regulated ecSOD in the aorta and in left ventricular tissue but remained unchanged in lung tissue. Catalase expression in lung tissue and vena cava of exercised mice exceeded that in aorta by 6.9- and 10-fold, respectively, suggesting a lack of stimulatory effects of hydrogen peroxide. In accordance, treatment of mice with the catalase inhibitor aminotriazole for 6 weeks resulted in significant up-regulation of eNOS and ecSOD in vena cava. These data suggest that physiological venous catalase activity prevents exercise-induced up-regulation of eNOS and ecSOD. Furthermore, therapeutic inhibition of vascular catalase might improve pulmonary rehabilitation. PMID:21129156

  2. Catalases of Aspergillus fumigatus

    PubMed Central

    Paris, Sophie; Wysong, Deborah; Debeaupuis, Jean-Paul; Shibuya, Kazutoshi; Philippe, Bruno; Diamond, Richard D.; Latgé, Jean-Paul

    2003-01-01

    Upon infection of a host, the pathogenic fungus Aspergillus fumigatus is attacked by the reactive oxygen species produced by phagocytic cells. Detoxification of hydrogen peroxide by catalases was proposed as a way to overcome this host response. A. fumigatus produces three active catalases; one is produced by conidia, and two are produced by mycelia. The mycelial catalase Cat1p was studied previously. Here we characterized the two other catalases, their genes, and the phenotypes of gene-disrupted mutants. CatAp, a spore-specific monofunctional catalase, is resistant to heat, metal ions, and detergent. This enzyme is a dimeric protein with 84.5-kDa subunits. The 749-amino-acid polypeptide exhibits high levels of similarity to the Aspergillus nidulans CatA catalase and to bacterial catalase HPII of Escherichia coli. In spite of increased sensitivity to H2O2, killing of ?catA conidia by alveolar macrophages and virulence in animals were similar to the killing of conidia by alveolar macrophages and virulence in animals observed for the wild type. In contrast to the Cat1p and CatAp catalases, the mycelial Cat2p enzyme is a bifunctional catalase-peroxidase and is sensitive to heat, metal ions, and detergent. This enzyme, an 82-kDa monomer, is homologous to catalase-peroxidases of several fungi and bacteria. Surprisingly, mycelium of the double ?cat1?cat2 mutant with no catalase activity exhibited only slightly increased sensitivity to H2O2 and was as sensitive to killing by polymorphonuclear neutrophils as mycelium of the wild-type strain. However, this mutant exhibited delayed infection in the rat model of aspergillosis compared to infection by the wild-type strain. These results indicate that conidial catalase is not a virulence factor and that mycelial catalases transiently protect the fungus from the host. PMID:12761140

  3. Catalase Test Protocol

    NSDL National Science Digital Library

    American Society For Microbiology

    2010-11-11

    The catalase test is used to detect the presence of the enzyme catalase in bacteria. Catalase serves to neutralize the bactericidal effects of hydrogen peroxide. Its concentration in bacteria has been correlated with pathogenicity. This enzymatic test is essential in the scheme of identification for gram-positive organisms and certain gram-negative organisms. It is a primary test used in the differentiation of staphylococci and streptococci.

  4. Cancer and Human Liver Catalase

    Microsoft Academic Search

    EDWARD E. MASON; TING-FONG CHIN; YAO W. LI; SIDNEY E. ZIFFREN

    1960-01-01

    SUMMARY Data presented in the present paper indicate that human liver catalase depression is related to weight loss. A statistical study was first made to determine the catalase activity in correlation of the iodotitrimetric and spectrophotometric methods for biopsy and autopsy samples from cancer and cancer-free patients. Cancer patients had a 2~ per cent lower liver catalase activity than cancer-free

  5. Non-heme manganese catalase – the ‘other’ catalase

    PubMed Central

    Whittaker, James W.

    2012-01-01

    Non-heme manganese catalases are widely distributed over microbial life and represent an environmentally important alternative to heme-containing catalases in antioxidant defense. Manganese catalases contain a binuclear manganese complex as their catalytic active site rather than a heme, and cycle between Mn2(II,II) and Mn2(III,III) states during turnover. X-ray crystallography has revealed the key structural elements of the binuclear manganese active site complex that can serve as the starting point for computational studies on the protein. Four manganese catalase enzymes have been isolated and characterized, and the enzyme appears to have a broad phylogenetic distribution including both bacteria and archae. More than 100 manganese catalase genes have been annotated in genomic databases, although the assignment of many of these putative manganese catalases needs to be experimentally verified. Iron limitation, exposure to low levels of peroxide stress, thermostability and cyanide resistance may provide the biological and environmental context for the occurrence of manganese catalases. PMID:22198285

  6. In Vitro Assembly of Catalase*

    PubMed Central

    Baureder, Michael; Barane, Elisabeth; Hederstedt, Lars

    2014-01-01

    Most aerobic organisms contain catalase, which functions to decompose hydrogen peroxide. Typical catalases are structurally complex homo-tetrameric enzymes with one heme prosthetic group buried in each subunit. It is not known how catalase in the cell is assembled from its constituents. The bacterium Enterococcus faecalis cannot synthesize heme but can acquire it from the environment to form a cytoplasmic catalase. We have in E. faecalis monitored production of the enzyme polypeptide (KatA) depending on the availability of heme and used our findings to devise a procedure for the purification of preparative amounts of in vivo-synthesized apocatalase. We show that fully active catalase can be obtained in vitro by incubating isolated apoprotein with hemin. We have characterized features of the assembly process and describe a temperature-trapped hemylated intermediate of the enzyme maturation process. Hemylation of apocatalase does not require auxiliary cell components, but rapid assembly of active enzyme seemingly is assisted in the cell. Our findings provide insight about catalase assembly and offer new experimental possibilities for detailed studies of this process. PMID:25148685

  7. Liver Catalase Activity in Rat Leukemia

    Microsoft Academic Search

    ARTHUR A. SPECTOR; LEONARD BERWICK; PETER C. NOWELL

    SUMMARY Liver catalase activity in rats bearing a transplanted lymphocytic leukemia showed progressive changes that were similar to those reported for solid neoplasms in a rodent. There was an initial drop in the recipient's liver catalase activity upon inoculation with blood from a leukemic donor. This was followed by a return to normal liver catalase activity levels and then by

  8. Catalase and glutathione peroxidase mimics

    PubMed Central

    Day, Brian J.

    2009-01-01

    Overproduction of the reactive oxygen species (ROS) superoxide (O2?) and hydrogen peroxide (H2O2) are increasingly implicated in human disease and aging. ROS are also being explored as important modulating agents in a number of cell signaling pathways. Earlier work has focused on development of small catalytic scavengers of O2?, commonly referred to as superoxide dismutase (SOD) mimetics. Many of these compounds also have substantial abilities to catalytically scavenge H2O2 and peroxynitrite (ONOO?). Peroxides have been increasingly shown to disrupt cell signaling cascades associated with excessive inflammation associated with a wide variety of human diseases. Early studies with enzymatic scavengers like SOD frequently reported little or no beneficial effect in biologic models unless SOD was combined with catalase or a peroxidase. Increasing attention has been devoted to developing catalase or peroxidase mimetics as a way to treat overt inflammation associated with the pathophysiology of many human disorders. This review will focus on recent development of catalytic scavengers of peroxides and their potential use as therapeutic agents for pulmonary, cardiovascular, neurodegenerative and inflammatory disorders. PMID:18948086

  9. Purification and characterization of liver catalase in acatalasemic beagle dog: comparison with normal dog liver catalase

    Microsoft Academic Search

    Kouichi Nakamura; Misa Watanabe; Yukio Sasaki; Toshihiko Ikeda

    2000-01-01

    Catalase from acatalasemic dog liver was purified to homogeneity and its properties were compared with those of normal dog liver catalase. The purified acatalasemic and normal dog liver catalases were found to have the same molecular weight (230,000 Da) and isoelectric point (pI: 6.0–6.2) and both enzymes contained four hematins per molecule. The catalytic activity of catalase from acatalasemic dog

  10. Evolution of Catalases from Bacteria to Humans

    PubMed Central

    Zamocky, Marcel; Furtmüller, Paul G.; Obinger, Christian

    2010-01-01

    Excessive hydrogen peroxide is harmful for almost all cell components, so its rapid and efficient removal is of essential importance for aerobically living organisms. Conversely, hydrogen peroxide acts as a second messenger in signal-transduction pathways. H2O2 is degraded by peroxidases and catalases, the latter being able both to reduce H2O2 to water and to oxidize it to molecular oxygen. Nature has evolved three protein families that are able to catalyze this dismutation at reasonable rates. Two of the protein families are heme enzymes: typical catalases and catalase–peroxidases. Typical catalases comprise the most abundant group found in Eubacteria, Archaeabacteria, Protista, Fungi, Plantae, and Animalia, whereas catalase–peroxidases are not found in plants and animals and exhibit both catalatic and peroxidatic activities. The third group is a minor bacterial protein family with a dimanganese active site called manganese catalases. Although catalyzing the same reaction (2 H2O2 ? 2 H2O + O2), the three groups differ significantly in their overall and active-site architecture and the mechanism of reaction. Here, we present an overview of the distribution, phylogeny, structure, and function of these enzymes. Additionally, we report about their physiologic role, response to oxidative stress, and about diseases related to catalase deficiency in humans. PMID:18498226

  11. Catalase Activity in the Epidermis of Patients with Advanced Cancer

    Microsoft Academic Search

    Geoffrey Falkson; M. E. de Jager

    1964-01-01

    HUMAN liver catalase is depressed in patients with advanced cancer. Clinical improvement may cause a rise in liver catalase1. An investigation was, therefore, undertaken to determine whether skin catalase was subject to the same variations. As depression of human liver catalase has been shown to be related to loss in weight2, attention was directed to this aspect of the problem.

  12. Oxygen metabolism of catalase-negative and catalase-positive strains of Lactobacillus plantarum.

    PubMed Central

    Yousten, A A; Johnson, J L; Salin, M

    1975-01-01

    Two catalase-negative strains of Lactobacillus plantarum and a strain producing the atypical, nonheme catalase were studied to determine if the ability to produce the atypical catalase conferred any growth advantage upon the producing strain. Both catalase-negative strains grew more rapidly than the catalase-positive strain under aerobic or anaerobic conditions in a glucose-containing, complex medium. Upon exhaustion of glucose from the medium, all three strains continued growth under aerobic but not under anaerobic conditions. The continued aerobic growth was accompanied by production of acetic acid in addition to the lactic acid produced during growth on glucose. Oxygen was taken up by exponential phase-cell suspensions grown on glucose when glucose or glycerol were used as substrates. Cells harvested from glucose-exhausted medium oxidized glucose, glycerol, and pyruvate. Oxygen utilization by a catalase-negative strain increased as did the specific activity of reduced nicotinamide adenine dinucleotide peroxidase during late growth in the glucose-exhausted medium. The catalase-positive strain and the catalase-negative strain tested both possessed low but readily detectable levels of superoxide dismutase throughout growth. The growth responses are discussed in terms of the presence of enzymes which would allow the cells to remove potentially damaging reduction products of O2. PMID:1141195

  13. Discovery of Catalases in Members of the Chlamydiales Order

    PubMed Central

    Rusconi, Brigida

    2013-01-01

    Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment. PMID:23729651

  14. Protection of Bacillus pumilus spores by catalases.

    PubMed

    Checinska, Aleksandra; Burbank, Malcolm; Paszczynski, Andrzej J

    2012-09-01

    Bacillus pumilus SAFR-032, isolated at spacecraft assembly facilities of the National Aeronautics and Space Administration Jet Propulsion Laboratory, is difficult to kill by the sterilization method of choice, which uses liquid or vapor hydrogen peroxide. We identified two manganese catalases, YjqC and BPUM_1305, in spore protein extracts of several B. pumilus strains by using PAGE and mass spectrometric analyses. While the BPUM_1305 catalase was present in six of the B. pumilus strains tested, YjqC was not detected in ATCC 7061 and BG-B79. Furthermore, both catalases were localized in the spore coat layer along with laccase and superoxide dismutase. Although the initial catalase activity in ATCC 7061 spores was higher, it was less stable over time than the SAFR-032 enzyme. We propose that synergistic activity of YjqC and BPUM_1305, along with other coat oxidoreductases, contributes to the enhanced resistance of B. pumilus spores to hydrogen peroxide. We observed that the product of the catalase reaction, gaseous oxygen, forms expanding vesicles on the spore surface, affecting the mechanical integrity of the coat layer, resulting in aggregation of the spores. The accumulation of oxygen gas and aggregations may play a crucial role in limiting further exposure of Bacilli spore surfaces to hydrogen peroxide or other toxic chemicals when water is present. PMID:22752169

  15. Mutagenesis in Escherichia coli lacking catalase.

    PubMed

    Abril, N; Pueyo, C

    1990-01-01

    Escherichia coli K-12 strains completely lacking catalase activity due to mutations in katG, katE, and katF genes were constructed in order to assess the role of hydrogen peroxide in mutagenesis. Mutagenesis was monitored by selecting forward mutations to L-arabinose resistance. Lethality was measured at experimental conditions equivalent to those of the mutant yield by using a mixed culture of pairs of isogenic strains distinguished by their differential nutritional requirements. Deficiency in katG, katE, and katF genes leads to an enhanced spontaneous mutation rate as well as an enhanced sensitivity to both the lethal and mutagenic effects of hydrogen peroxide or an H2O2-generating mixture of compounds, such as coffee. To compare further the responses of the catalase-deficient bacteria to those of catalase-proficient counterparts, other genotoxins were analyzed. Both catalase-deficient and catalase-proficient strains were equally mutated by MMS, 4-NQO, and ultraviolet light. It is concluded that the bacterial strains and the mutagenicity tests described in the paper represent a useful tool to study the role of H2O2 in mutagenesis. PMID:2192882

  16. HYDROGEN PEROXIDE INDUCED OXIDATION OF PEROXISOMAL MALATE SYNTHASE AND CATALASE.

    E-print Network

    Simha, Rahul

    Page 1 HYDROGEN PEROXIDE INDUCED OXIDATION OF PEROXISOMAL MALATE SYNTHASE AND CATALASE. Pria Anand1 locations within the proteins' structures. Key words: biotin hydrazide, carbonylation, catalase, hydrogen peroxide, glyoxysome, MALDI- TOF MS, malate synthase, mass spectroscopy, peroxisome, protein oxidation

  17. Inhibition of catalase activity in vitro by diesel exhaust particles

    Microsoft Academic Search

    Yoki Mori; Sumika Murakami; Toshiyuki Sagae

    1996-01-01

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because HâOâ is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase

  18. Quantitation of catalase activity by microspectrophotometry after diaminobenzidine staining

    Microsoft Academic Search

    A. Geerts; F. Roels

    1981-01-01

    The absorbance of the reaction product of catalase staining with diaminobenzidine is linearly proportional to enzyme activity. This is shown in semithin Epon sections of model systems containing serum albumin and catalase from bovine or guinea pig liver. Absorbance measurements were also performed on semithin sections of guinea pig liver, and from these, the activity of cytoplasmic (extraperoxisomal) catalase has

  19. Growth-dependent catalase localization in Exiguobacterium oxidotolerans T-2-2T reflected by catalase activity of cells.

    PubMed

    Hanaoka, Yoshiko; Takebe, Fumihiko; Nodasaka, Yoshinobu; Hara, Isao; Matsuyama, Hidetoshi; Yumoto, Isao

    2013-01-01

    A psychrotolerant and H2O2-resistant bacterium, Exiguobacterium oxidotolerans T-2-2(T), exhibits extraordinary H2O2 resistance and produces catalase not only intracellularly but also extracellularly. The intracellular and extracellular catalases exhibited the same enzymatic characteristics, that is, they exhibited the temperature-dependent activity characteristic of a cold-adapted enzyme, their heat stabilities were similar to those of mesophilic enzymes and very high catalytic intensity. In addition, catalase gene analysis indicated that the bacterium possessed the sole clade 1 catalase gene corresponding to intracellular catalase. Hence, intracellular catalase is secreted into the extracellular space. In addition to intracellular and extracellular catalases, the inner circumference of the cells showed the localization of catalase in the mid-stationary growth phase, which was observed by immunoelectron microscopy using an antibody against the intracellular catalase of the strain. The cells demonstrated higher catalase activity in the mid-stationary growth phase than in the exponential growth phase. The catalase localized in the inner circumference can be dissociated by treatment with Tween 60. Thus, the localized catalase is not tightly bound to the inner circumference of the cells and may play a role in the oxidative defense of the cells under low metabolic state. PMID:24204687

  20. Molecular Characterization of a Catalase from Hydra vulgaris

    PubMed Central

    Dash, Bhagirathi; Phillips, Timothy D.

    2012-01-01

    Catalase, an antioxidant and hydroperoxidase enzyme protects the cellular environment from harmful effects of hydrogen peroxide by facilitating its degradation to oxygen and water. Molecular information on a cnidarian catalase and/or peroxidase is, however, limited. In this work an apparent full length cDNA sequence coding for a catalase (HvCatalase) was isolated from Hydra vulgaris using 3’- and 5’- (RLM) RACE approaches. The 1859 bp HvCatalase cDNA included an open reading frame of 1518 bp encoding a putative protein of 505 amino acids with a predicted molecular mass of 57.44 kDa. The deduced amino acid sequence of HvCatalase contained several highly conserved motifs including the heme-ligand signature sequence RLFSYGDTH and the active site signature FXRERIPERVVHAKGXGA. A comparative analysis showed the presence of conserved catalytic amino acids [His(71), Asn(145), and Tyr(354)] in HvCatalase as well. Homology modeling indicated the presence of the conserved features of mammalian catalase fold. Hydrae exposed to thermal, starvation, metal and oxidative stress responded by regulating its catalase mRNA transcription. These results indicated that the HvCatalase gene is involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure. PMID:22521743

  1. Regulation of catalase enzyme activity by cell signaling molecules

    Microsoft Academic Search

    Sumio Yano; Noriko Yano

    2002-01-01

    Mitogenic cell proliferation requires a rapid and transient H2O2 generation, which is blocked by catalase or PKA activators. Previously, we observed that anemic HIV(+) individuals expressed acidic pIs of catalase in RBC with significantly high activities [Mol Cell Biochem 165: 77–81, 1996]. These findings led us to hypothesize that cell signaling molecules regulate catalase to control cell mitogenesis. To test

  2. A eukaryote without catalase-containing microbodies: Neurospora crassa exhibits a unique cellular distribution of its four catalases.

    PubMed

    Schliebs, Wolfgang; Würtz, Christian; Kunau, Wolf-Hubert; Veenhuis, Marten; Rottensteiner, Hanspeter

    2006-09-01

    Microbodies usually house catalase to decompose hydrogen peroxide generated within the organelle by the action of various oxidases. Here we have analyzed whether peroxisomes (i.e., catalase-containing microbodies) exist in Neurospora crassa. Three distinct catalase isoforms were identified by native catalase activity gels under various peroxisome-inducing conditions. Subcellular fractionation by density gradient centrifugation revealed that most of the spectrophotometrically measured activity was present in the light upper fractions, with an additional small peak coinciding with the peak fractions of HEX-1, the marker protein for Woronin bodies, a compartment related to the microbody family. However, neither in-gel assays nor monospecific antibodies generated against the three purified catalases detected the enzymes in any dense organellar fraction. Furthermore, staining of an N. crassa wild-type strain with 3,3'-diaminobenzidine and H(2)O(2) did not lead to catalase-dependent reaction products within microbodies. Nonetheless, N. crassa does possess a gene (cat-4) whose product is most similar to the peroxisomal type of monofunctional catalases. This novel protein indeed exhibited catalase activity, but was not localized to microbodies either. We conclude that N. crassa lacks catalase-containing peroxisomes, a characteristic that is probably restricted to a few filamentous fungi that produce little hydrogen peroxide within microbodies. PMID:16963632

  3. Interaction of Nitric Oxide with Catalase: Structural and Kinetic Analysis

    PubMed Central

    2011-01-01

    We present the structures of bovine catalase in its native form and complexed with ammonia and nitric oxide, obtained by X-ray crystallography. Using the NO generator 1-(N,N-diethylamino)diazen-1-ium-1,2-diolate, we were able to generate sufficiently high NO concentrations within the catalase crystals that substantial occupation was observed despite a high dissociation rate. Nitric oxide seems to be slightly bent from the heme normal that may indicate some iron(II) character in the formally ferric catalase. Microspectrophotometric investigations inline with the synchrotron X-ray beam reveal photoreduction of the central heme iron. In the cases of the native and ammonia-complexed catalase, reduction is accompanied by a relaxation phase. This is likely not the case for the catalase NO complex. The kinetics of binding of NO to catalase were investigated using NO photolyzed from N,N?-bis(carboxymethyl)-N,N?-dinitroso-p-phenylenediamine using an assay that combines catalase with myoglobin binding kinetics. The off rate is 1.5 s–1. Implications for catalase function are discussed. PMID:21524057

  4. Catalase Deficiency Accelerates Diabetic Renal Injury Through Peroxisomal Dysfunction

    PubMed Central

    Hwang, Inah; Lee, Jiyoun; Huh, Joo Young; Park, Jehyun; Lee, Hi Bahl; Ho, Ye-Shih; Ha, Hunjoo

    2012-01-01

    Mitochondrial reactive oxygen species (ROS) play an important role in diabetes complications, including diabetic nephropathy (DN). Plasma free fatty acids (FFAs) as well as glucose are increased in diabetes, and peroxisomes and mitochondria participate in FFA oxidation in an interconnected fashion. Therefore, we investigated whether deficiency of catalase, a major peroxisomal antioxidant, accelerates DN through peroxisomal dysfunction and abnormal renal FFA metabolism. Diabetes was induced by multiple injections of low-dose streptozotocin into catalase knock-out (CKO) and wild-type (WT) C57BL/6 mice. Murine mesangial cells (MMCs) transfected with catalase small interfering RNA followed by catalase overexpression were used to further elucidate the role of endogenous catalase. Despite equivalent hyperglycemia, parameters of DN, along with markers of oxidative stress, were more accelerated in diabetic CKO mice than in diabetic WT mice up to 10 weeks of diabetes. CKO mice and MMCs showed impaired peroxisomal/mitochondrial biogenesis and FFA oxidation. Catalase deficiency increased mitochondrial ROS and fibronectin expression in response to FFAs, which were effectively restored by catalase overexpression or N-acetylcysteine. These data provide unprecedented evidence that FFA-induced peroxisomal dysfunction exacerbates DN and that endogenous catalase plays an important role in protecting the kidney from diabetic stress through maintaining peroxisomal and mitochondrial fitness. PMID:22315314

  5. Low Catalase Levels in the Epidermis of Patients with Vitiligo

    Microsoft Academic Search

    Karin U. Schallreuter; John M. Wood; Jürgen Berger

    1991-01-01

    Suction blister roofs taken from the involve and uninvolved epidermis of patients with vitiligo showed a consistent reduction in level of catalase compared to normal healthy controls of matched photo-skin types (Fitzpatrick classification). A decrease in catalase activity is expected to increase the concentration of hydrogen peroxide in the epidermis of these patients. Hydrogen peroxide function as a reversible inhibitor

  6. The effect of various food parameters on the activity and stability of catalase from Aspergillus niger and catalase from bovine liver

    Microsoft Academic Search

    Anne S. Meyer; Lærke H. Pedersen; Anette Isaksen

    1997-01-01

    The effects of a number of food relevant parameters on catalase activity and stability were studied. The direct responses of different combinations of the parameters ethanol, pH and ionic strength on bovine liver catalase and Aspergillus niger catalase activity were investigated in a full factorial 24 statistically designed experiment. Statistically significant effects (p = 0.001) on both types of catalases

  7. Amyloid-beta binds catalase with high affinity and inhibits hydrogen peroxide breakdown.

    PubMed Central

    Milton, N G

    1999-01-01

    Amyloid-beta (Abeta) specifically bound purified catalase with high affinity and inhibited catalase breakdown of H(2)O(2). The Abeta-induced catalase inhibition involved formation of the inactive catalase Compound II and was reversible. Catalase<-->Abeta interactions provide rapid functional assays for the cytotoxic domain of Abeta and suggest a mechanism for some of the observed actions of Abeta plus catalase in vitro. PMID:10567208

  8. Characterization and spectral properties of Proteus mirabilis PR catalase.

    PubMed

    Jouve, H M; Gaillard, J; Pelmont, J

    1984-10-01

    Purified catalase from a peroxide-resistant mutant (PR) of Proteus mirabilis displayed great similarities with the bovine liver catalase on the basis of its amino acid composition, content in prosthetic groups, and spectroscopic data. The bacterial enzyme was found to have 2.6 +/- 0.2 mol of protoheme IX per tetramer, with an equivalent amount of titrable iron atoms. The optical absorption of P. mirabilis PR catalase in the presence of various anionic species (cyanide, azide, formate) was examined. The dissociation constant of the formate-enzyme complex was determined as 60 +/- 2 mM at pH 7.5. Inhibition and spectral shifts induced by some thiol compounds were very similar to those reported with mammalian catalase. The electron paramagnetic resonance (EPR) spectra (at 9 GHz and 6 K) of bacterial catalase and its various complexes were reported. Two major different rhombic high-spin ferric signals could be seen in the g = 6 region, using either the pure enzyme or the cell crude extract. The balance between the two rhombic forms was reversibly altered by pH. Various changes in rhombicity were also observed after binding with anionic ligands. The EPR spectrum (at 40 K) of nitrosyl ferrous catalase was very similar to reported data with horse liver catalase. PMID:6095975

  9. The catalase activity of diiron adenine deaminase

    PubMed Central

    Kamat, Siddhesh S; Holmes-Hampton, Gregory P; Bagaria, Ashima; Kumaran, Desigan; Tichy, Shane E; Gheyi, Tarun; Zheng, Xiaojing; Bain, Kevin; Groshong, Chris; Emtage, Spencer; Sauder, J Michael; Burley, Stephen K; Swaminathan, Subramanyam; Lindahl, Paul A; Raushel, Frank M

    2011-01-01

    Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron was sequestered with a metal chelator and the growth medium supplemented with Mn2+ before induction, the post-translational modifications disappeared. Enzyme expressed and purified under these conditions was substantially more active for adenine deamination. Apo-enzyme was prepared and reconstituted with two equivalents of FeSO4. Inductively coupled plasma mass spectrometry and Mössbauer spectroscopy demonstrated that this protein contained two high-spin ferrous ions per monomer of ADE. In addition to the adenine deaminase activity, [FeII/FeII]-ADE catalyzed the conversion of H2O2 to O2 and H2O. The values of kcat and kcat/Km for the catalase activity are 200 s?1 and 2.4 × 104 M?1 s?1, respectively. [FeII/FeII]-ADE underwent more than 100 turnovers with H2O2 before the enzyme was inactivated due to oxygenation of histidine residues critical for metal binding. The iron in the inactive enzyme was high-spin ferric with gave = 4.3 EPR signal and no evidence of anti-ferromagnetic spin-coupling. A model is proposed for the disproportionation of H2O2 by [FeII/FeII]-ADE that involves the cycling of the binuclear metal center between the di-ferric and di-ferrous oxidation states. Oxygenation of active site residues occurs via release of hydroxyl radicals. These findings represent the first report of redox reaction catalysis by any member of the AHS. PMID:21998098

  10. Catalases as biocatalysts in technical applications: current state and perspectives.

    PubMed

    Lon?ar, Nikola; Fraaije, Marco W

    2015-04-01

    Catalases represent a class of enzymes which has found its place among industrially relevant biocatalysts due to their exceptional catalytic rate and high stability. Textile bleaching prior to the dyeing process is the main application and has been performed on a large scale for the past few decades. Their limited substrate scope has not prevented the development of various other catalase-based applications. Newly developed approaches continue to exploit their excellent catalytic potential to degrade hydrogen peroxide while (per)oxidase activity of catalases is opening a new range of possibilities as well. This review provides an overview of applications that involve heme-containing catalases that have been demonstrated in recent years. PMID:25761626

  11. Increased effective activity of rat liver catalase by dietary restriction

    Microsoft Academic Search

    Ritchie J. Feuers; Richard Weindruch; Julian E. A. Leakey; Peter H. Duffy; Ronald W. Hart

    1997-01-01

    While dietary restriction (DR) increases maximum life span in many animal species, the mechanisms by which this is achieved\\u000a remain unclear. One possibility is that DR may act in part to reduce free radical levels by retarding age-related declines\\u000a in rat liver catalase activity. We measured liver cytosolic catalase activity at various times of day in 9–12 month old male

  12. Regulation of Catalase Activity in Mice of Different Ages

    Microsoft Academic Search

    M. B. Baird; H. V. Samis

    1971-01-01

    The renewal of catalase activity in C57BL\\/6J male mice of different ages was followed for 24 h after the removal of activity with 3-amino-1,2,4,-triazole (AT). The return of activity after injection of AT in both liver and kidney of old animals was significantly slower than that of either young or middle-aged mice. Some old mice failed to renew any catalase

  13. Purification and Characterization of a Catalase from the Facultatively Psychrophilic Bacterium Vibrio rumoiensis S-1T Exhibiting High Catalase Activity

    Microsoft Academic Search

    ISAO YUMOTO; DAISEN ICHIHASHI; HIDEAKI IWATA; ANITA ISTOKOVICS; NOBUTOSHI ICHISE; HIDETOSHI MATSUYAMA; HIDETOSHI OKUYAMA; KOSEI KAWASAKI

    2000-01-01

    Catalase from the facultatively psychrophilic bacterium Vibrio rumoiensis S-1 T , which was isolated from an environment exposed to H2O2 and exhibited high catalase activity, was purified and characterized, and its localization in the cell was determined. Its molecular mass was 230 kDa, and the molecule consisted of four identical subunits. The enzyme, which was not apparently reduced by dithionite,

  14. Purification and biosynthesis of cottonseed (Gossypium hirsutum L.) catalase.

    PubMed

    Kunce, C M; Trelease, R N; Turley, R B

    1988-04-01

    As part of our research on peroxisome biogenesis, catalase was purified from cotyledons of dark-grown cotton (Gossypium hirsutum L.) seedlings and monospecific antibodies were raised in rabbits. Purified catalase appeared as three distinct electrophoretic forms in non-denaturing gels and as a single protein band (with a subunit Mr of 57,000) on silver-stained SDS/polyacrylamide gels. Western blots of crude extracts and isolated peroxisomes from cotton revealed one immunoreactive polypeptide with the same Mr (57,000) as the purified enzyme, indicating that catalase did not undergo any detectable change in Mr during purification. Synthesis in vitro, directed by polyadenylated RNA isolated from either maturing seeds or cotyledons of dark-grown cotton seedlings, revealed a predominant immunoreactive translation product with a subunit Mr of 57,000 and an additional minor immunoreactive product with a subunit Mr of 64000. Labelling studies in vivo revealed newly synthesized monomers of both the 64000- and 57,000-Mr proteins present in the cytosol and incorporation of both proteins into the peroxisome without proteolytic processing. Within the peroxisome, the 57,000-Mr catalase was found as an 11S tetramer; whereas the 64,000-Mr protein was found as a relatively long-lived 20S aggregate (native Mr approx. 600,000-800,000). The results strongly indicate that the 64,000-Mr protein (catalase?) is not a precursor to the 57,000-Mr catalase and that cotton catalase is translated on cytosolic ribosomes without a cleavable transit or signal sequence. PMID:3134010

  15. Isoflavone daidzein possesses no antioxidant activities in cell-free assays but induces the antioxidant enzyme catalase.

    PubMed

    Kampkötter, Andreas; Chovolou, Yvonni; Kulawik, Andreas; Röhrdanz, Elke; Weber, Nadine; Proksch, Peter; Wätjen, Wim

    2008-09-01

    Epidemiologic studies have shown that dietary intake of isoflavonones is associated with several properties beneficial to human health. It has been suggested that at least some of these effects are related to the antioxidant activity of isoflavonoids. We analyzed the antioxidant activity of the major isoflavones found in soybeans, but none of these compounds showed prominent antioxidant effects in cell-free assay systems (trolox equivalent antioxidant capacity assay and 2,2-diphenyl-1-picrylhydrazyl assay). Therefore, we examined the hypothesis that the antioxidative effects of isoflavones are caused indirectly by up-regulation of antioxidative enzymes, thereby lowering intracellular concentration of reactive oxygene species. Daidzein shows a significant induction of catalase promoter activity at 100 micromol/L in a reporter gene assay and at 200 micromol/L in Northern blot experiments. Another hypothesis for antioxidant effects caused by isoflavones is due to metabolism by intestinal bacteria. Analyzing the daidzein metabolites 3'-OH-daidzein and 6-OH-daidzein in our cell culture model, we found strong antioxidant effects (2,2-diphenyl-1-picrylhydrazyl and trolox equivalent antioxidant capacity assay). We conclude that isoflavone daidzein up-regulates the antioxidant enzyme catalase but shows only little antioxidant capacity per se. Antioxidant effects of this dietary isoflavonone may also be due to formation of the antioxidant metabolites 6-OH-daidzein and 3'-OH-daidzein. PMID:19083468

  16. A Simple Assay for Measuring Catalase Activity: A Visual Approach

    PubMed Central

    Iwase, Tadayuki; Tajima, Akiko; Sugimoto, Shinya; Okuda, Ken-ichi; Hironaka, Ippei; Kamata, Yuko; Takada, Koji; Mizunoe, Yoshimitsu

    2013-01-01

    In this study, an assay that combines the ease and simplicity of the qualitative approach for measuring catalase activity was developed. The assay reagents comprised only hydrogen peroxide and Triton X-100. The enzyme-generated oxygen bubbles trapped by Triton X-100 were visualized as foam, whose height was estimated. A calibration plot using the defined unit of catalase activity yielded the best linear fit over a range of 20–300 units (U) (y = 0.3794x ? 2.0909, r2 = 0.993). The assay precision and reproducibility at 100 U were 4.6% and 4.8%, respectively. The applicability of the assay for measuring the catalase activity of various samples was assessed using laboratory strains of Escherichia coli, catalase-deficient isogenic mutants, clinically isolated Shiga toxin-producing E. coli, and human cells. The assay generated reproducible results. In conclusion, this new assay can be used to measure the catalase activity of bacterial isolates and human cells. PMID:24170119

  17. Improving catalase-based propelled motor endurance by enzyme encapsulation.

    PubMed

    Simmchen, Juliane; Baeza, Alejandro; Ruiz-Molina, Daniel; Vallet-Regí, Maria

    2014-08-01

    Biocatalytic propulsion is expected to play an important role in the future of micromotors as it might drastically increase the number of available fuelling reactions. However, most of the enzyme-propelled micromotors so far reported still rely on the degradation of peroxide by catalase, in spite of being vulnerable to relatively high peroxide concentrations. To overcome this limitation, herein we present a strategy to encapsulate the catalase and to graft the resulting enzyme capsules on motor particles. Significant improvement of the stability in the presence of peroxide and other aggressive agents has been observed. PMID:24964766

  18. Development of lyophilization cycle and effect of excipients on the stability of catalase during lyophilization

    PubMed Central

    Lale, Shantanu V; Goyal, Monu; Bansal, Arvind K

    2011-01-01

    Introduction: The purpose of the present study was to screen excipients such as amino acids and non-aqueous solvents for their stabilizing effect on catalase, a model protein, for lyophilization. The present study also includes optimization of lyophilization cycle for catalase formulations, which is essential from the commercial point of view, since lyophilization is an extremely costly process. Materials and Methods: Activity of catalase was determined using catalase activity assay. Differential scanning calorimetry was used to determine eutectic melting temperature of the frozen catalase solution, which is essential for the optimization of lyophilization cycle. Results: When catalase was lyophilized without excipients, it was found that about 65-78% of the initial activity of catalase was lost during the lyophilization process in a concentration dependent manner. The maximum stability of catalase during lyophilization was observed at pH 7.0. Amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline showed strong stabilizing effect on catalase during lyophilization by protecting catalase activity above 95%, whereas valine and cysteine hydrochloride showed destabilizing effect on catalase. Non-aqueous solvents such as dimethyl formamide, dimethyl sulphoxide, polyethylene glycol (PEG) 200, PEG 400, PEG 600 and ethylene glycol also showed destabilizing effect on catalase during lyophilization. Conclusions: In order to prevent loss of catalase activity during lyophilization of catalase, use of amino acids like alanine, glycine, lysine, serine and 4-hydroxy proline in optimum concentration is highly advisable. PMID:23071946

  19. Heterogeneity of catalase in maturing and germinated cotton seeds.

    PubMed

    Kunce, C M; Trelease, R N

    1986-08-01

    To investigate possible charge and size heterogeneity of catalase (EC 1.11.1.6) in cotton (Gossypium hirsutum L. cv Deltapine 62), extracts of cotyledons from different developmental ages were subjected to nondenaturing polyacrylamide gel electrophoresis and isoelectric focusing. Special precautions (e.g. fresh homogenates, reducing media) were necessary to prevent artefacts due to enzyme modification during extraction and storage. When the gels were stained for enzyme activity, two distinct electrophoretic forms of catalase were resolved in extracts of maturing and mature cotton seeds. In germinated seeds, three additional cathodic forms were detected revealing a total of five electrophoretic variants. In green cotyledons, the two anodic forms characteristic of ungerminated seeds were less active; whereas, the most cathodic form was predominant. All forms of catalase were found in isolated glyoxysomes. Corresponding electrophoretic patterns were found on Western blots probed with anticatalase serum; no immunoreactive, catalytically inactive forms were detected. Western blots of sodium dodecyl sulfate-polyacrylamide gels revealed only one immunoreactive (55 kilodaltons) polypeptide in cotton extracts of all developmental ages. Results from isoelectric focusing and Ferguson plots indicate that the electrophoretic variants of catalase are charge isomers with a molecular weight of approximately 230,000. PMID:16664956

  20. Effects of noise exposure on catalase activity of growing lymphocytes

    PubMed Central

    Nawaz, Syed Kashif; Hasnain, Shahida

    2011-01-01

    Oxidative stress due to noise was estimated at cell level using model of growing lymphocytes. Lymphocytes were isolated and cultured using conventional methodology. Cell culture of each group was exposed to sound of frequency 1 KHz during incubation. Three groups were defined on the basis of exposure of sound with specific range of intensity and duration of exposure. Group A and Group B were exposed to sound with intensity 110 dBA for four hours per day and for eight hours per day respectively. Control group was exposed to sound less than 85 dBA. Viable cell count was performed using trypan blue. Catalase activity of each group was estimated using ELISA kit. Viable cell count of Group A and Group B was almost same but significantly less than that of control group. Catalase activity of lymphocytes in Group B was significantly low as compared to Group A and controls (p=0.003,p< 0.05). There was no significant difference between catalase activity of Group A and control group. Exposure of sound with frequency 1 KHz and intensity 110 dBA for 4 hours and eight hours per day may induce oxidative stress in growing lymphocytes causing the difference in viable cell count. However the catalase activity depends on duration of exposure. In case of noise exposure of 8 hours per day, it declines significantly as compared to noise exposure of 4 hours per day. PMID:22117827

  1. Investigating Catalase Activity Through Hydrogen Peroxide Decomposition by Bacteria Biofilms in Real Time Using Scanning

    E-print Network

    Nishiguchi, Michele

    Investigating Catalase Activity Through Hydrogen Peroxide Decomposition by Bacteria Biofilms through hydrogen peroxide decomposition in a 1 mM bulk solution above Vibrio fischeri (-Protebacteria electrochemical microscopy (SECM). The catalase activity, in units of micromoles hydrogen peroxide decomposed per

  2. A Study of Crystalline Beef Liver Catalase Dried in the Frozen State

    Microsoft Academic Search

    Alexander L. Dounce; Joe W. Howland

    1943-01-01

    Crystalline beef liver catalase has been dried by the lyophile process, and the properties of the dried preparation have been compared with those of undried crystalline beef liver catalase. The dried material is not crystallizable, possesses about one third the activity per dry weight of undried crystalline beef liver catalase, and in contrast to the undried material, its hematin iron

  3. THE INFLUENCE OF X-RAY IRRADIATION ON THE LIVER CATALASE ACTIVITY

    Microsoft Academic Search

    T. Yanagisawa; N. Hiramatsu; Z. Iwasaki; H. Toda

    1961-01-01

    After whole-body exposure of 1000 r x rays, liver catalase activity of ; mlce was decreased for several days. The -catalase activity was decreased also ; after intraperttoneal administration of liver extract, urine, and serum prepared ; from the animal irradiated by x rays. Therefore, lt is suggested that the ; substance inhibiting liver catalase of mice is contained in

  4. Expression of the catalase and superoxide dismutase genes in mature pollen in maize

    Microsoft Academic Search

    A. Acevedo; J. G. Scandalios

    1990-01-01

    The expression of the Cat and Sod genes encoding the multiple catalases and superoxide dismutases in maize has been studied in maize pollen at anther dehiscence. Pollen from three catalase activity variant inbred lines was examined. Zymorgram analysis, immunoassays, and RNA blots show that, in the lines used, only the CAT-1 catalase isozyme is expressed in mature pollen; the CAT-2

  5. Structure of catalase determined by MicroED

    PubMed Central

    Nannenga, Brent L; Shi, Dan; Hattne, Johan; Reyes, Francis E; Gonen, Tamir

    2014-01-01

    MicroED is a recently developed method that uses electron diffraction for structure determination from very small three-dimensional crystals of biological material. Previously we used a series of still diffraction patterns to determine the structure of lysozyme at 2.9 Å resolution with MicroED (Shi et al., 2013). Here we present the structure of bovine liver catalase determined from a single crystal at 3.2 Å resolution by MicroED. The data were collected by continuous rotation of the sample under constant exposure and were processed and refined using standard programs for X-ray crystallography. The ability of MicroED to determine the structure of bovine liver catalase, a protein that has long resisted atomic analysis by traditional electron crystallography, demonstrates the potential of this method for structure determination. DOI: http://dx.doi.org/10.7554/eLife.03600.001 PMID:25303172

  6. Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases.

    PubMed Central

    Haas, A; Brehm, K; Kreft, J; Goebel, W

    1991-01-01

    A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the gram-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DH5 alpha as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately 50 times that of the combined E. coli catalases. The nucleotide sequence was determined, and the deduced amino acid sequence revealed 43.2% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of the L. seeligeri catalase gene. Images PMID:1860824

  7. The predominant protein in peroxisomal cores of sunflower cotyledons is a catalase that differs in primary structure from the catalase in the peroxisomal matrix.

    PubMed

    Kleff, S; Sander, S; Mielke, G; Eising, R

    1997-04-15

    This paper describes a biochemical study on the protein composition of crystalline inclusions (cores) from plant peroxisomes. By SDS/PAGE and immunoblotting, a catalase of 59 kDa was identified as the predominant protein component in purified cores from sunflower (Helianthus annuus L.) cotyledons. A 55-kDa catalase was the only additional peptide detected. In contrast to in cores, the 55-kDa catalase was the major catalase protein in matrix fractions obtained from lysed peroxisomes. These findings suggested two peroxisomal populations of catalase differing in molecular structure and subperoxisomal compartmentation in sunflower cotyledons. Evidence for different amino acid sequences of the two catalases was found by peptide mapping with endoproteinase Glu-C, by expressing a cDNA encoding matrix catalase in Escherichia coli, and by partial amino acid sequencing of peptide fragments from 59-kDa core catalase. These results contradict the previous view that the formation of cores occurred via condensation of matrix catalase, and indicate that new concepts on the biogenesis and physiological function of plant peroxisomal cores need to be developed. PMID:9151971

  8. cDNA cloning, characterization and expression analysis of catalase in swimming crab Portunus trituberculatus: cDNA cloning and expression analysis of catalase gene of Portunus trituberculatus.

    PubMed

    Chen, Ping; Li, Jitao; Liu, Ping; Gao, Baoquan; Wang, Qingyin; Li, Jian

    2012-12-01

    Catalase is an important antioxidant protein that protects organisms against various oxidative stresses by eliminating hydrogen peroxide. In the present study, a full-length cDNA sequence of catalase was cloned from the haemocytes of swimming crab Portunus trituberculatus by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA end method. The catalase cDNA sequence contained 1,851 bp with an open reading frame of 1,551 bp encoding 516 amino acid residues. The conserved catalytic active residues His-71, Asn-144 and Tyr-354 were predicted in the amino acid sequence of P. trituberculatus catalase. The deduced catalase protein had a calculated molecular mass of 58.5 kDa with an estimated isoelectric point of 6.90. Multiple alignment analysis revealed that the deduced amino acid sequence of catalase shared high identity of 68-95 % with those of other species. Quantitative real-time RT-PCR analysis revealed that P. trituberculatus catalase transcript was strongly detected in haemocytes, hepatopancreas, heart, stomach, intestine, gill, ovary and muscle. The expression level of catalase transcripts both in haemocytes and hepatopancreas changed rapidly and dynamically after Vibrio alginolyticus challenging. These facts indicate that catalase was perhaps involved in the acute response against invading bacteria and was an inducible protein involved in the host innate immune response through elimination of H(2)O(2) in crab. PMID:23073768

  9. Dual targeting of yeast catalase A to peroxisomes and mitochondria.

    PubMed Central

    Petrova, Ventsislava Y; Drescher, Diane; Kujumdzieva, Anna V; Schmitt, Manfred J

    2004-01-01

    Yeast catalase A (Cta1p) contains two peroxisomal targeting signals (SSNSKF) localized at its C-terminus and within the N-terminal third of the protein, which both can target foreign proteins to peroxisomes. In the present study we demonstrated that Cta1p can also enter mitochondria, although the enzyme lacks a classical mitochondrial import sequence. Cta1p co-targeting was studied in a catalase A null mutant after growth on different carbon sources, and expression of a Cta1p-GFP (green fluorescent protein)-fusion protein or a Cta1p derivative containing either a c-Myc epitope (Cta1p(myc)) or a SKF-extended tag (Cta1p(myc-SKF)). Peroxisomal and mitochondrial co-import of catalase A were tested qualitatively by fluorescence microscopy and functional complementation of a Delta cta1 null mutation, and quantitatively by subcellular fractionation followed by Western blot analysis and enzyme activity assays. Efficient Cta1p import into peroxisomes was observed when cells were cultivated under peroxisome-inducing conditions (i.e. growth on oleate), whereas significant co-import of Cta1p-GFP into mitochondria occurred when cells were grown under respiratory conditions that favour oxygen stress and ROS (reactive oxygen species) accumulation within this organelle. In particular, when cells were grown on the non-fermentable carbon source raffinose, respiration is maximally enhanced, and catalase A was efficiently targeted to the mitochondrial matrix where it presumably functions as scavenger of H2O2 and mitochondrial-derived ROS. PMID:14998369

  10. Adenoviral Gene Therapy With Catalase Suppresses Experimental Optic Neuritis

    Microsoft Academic Search

    John Guy; Xiaoping Qi; Hui Wang; William W. Hauswirth

    1999-01-01

    Objective: To determine if adenoviral-mediated trans- fer of the gene for catalase (CAT), the reactive oxygen spe- cies scavenger, suppresses experimental optic neuritis. Clinical Relevance: Gene therapy with CAT deliv- ered by an adeno-associated viral vector was previously shown to suppress experimental optic neuritis. Because the transduction of protein expression with recombi- nant adeno-associated viral vector is relatively slow, tak-

  11. Progeric effects of catalase inactivation in human cells

    SciTech Connect

    Koepke, Jay I.; Wood, Christopher S.; Terlecky, Laura J. [Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Avenue, Detroit, Michigan, 48201 (United States); Walton, Paul A. [Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario (Canada); Terlecky, Stanley R. [Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Avenue, Detroit, Michigan, 48201 (United States)], E-mail: srterlecky@med.wayne.edu

    2008-10-01

    Peroxisomes generate hydrogen peroxide, a reactive oxygen species, as part of their normal metabolism. A number of pathological situations exist in which the organelle's capacity to degrade the potentially toxic oxidant is compromised. It is the peroxidase, catalase, which largely determines the functional antioxidant capacity of the organelle, and it is this enzyme that is affected in aging, in certain diseases, and in response to exposure to specific chemical agents. To more tightly control the enzymatic activity of peroxisomal catalase and carefully document the effects of its impaired action on human cells, we employed the inhibitor 3-amino-1,2,4-triazole. We show that by chronically reducing catalase activity to approximately 38% of normal, cells respond in a dramatic manner, displaying a cascade of accelerated aging reactions. Hydrogen peroxide and related reactive oxygen species are produced, protein and DNA are oxidatively damaged, import into peroxisomes and organelle biogenesis is corrupted, and matrix metalloproteinases are hyper-secreted from cells. In addition, mitochondria are functionally impaired, losing their ability to maintain a membrane potential and synthesize reactive oxygen species themselves. These latter results suggest an important redox-regulated connection between the two organelle systems, a topic of considerable interest for future study.

  12. Are Catalase ?844A/G Polymorphism and Activity Associated with Childhood Obesity?

    PubMed Central

    Rupérez, Azahara I.; Olza, Josune; Gil-Campos, Mercedes; Leis, Rosaura; Mesa, María D.; Tojo, Rafael; Cañete, Ramón; Gil, Ángel

    2013-01-01

    Abstract Catalase (CAT) is a peroxisomal antioxidant enzyme that is up-regulated upon oxidative stress. Previous studies have found associations between some single nucleotide polymorphisms (SNPs) located in the CAT promoter region in a variety of metabolic diseases. This is the first study that analyzes the association between erythrocyte CAT activity and candidate CAT SNPs with childhood obesity. The association study showed a significant positive association of the promoter variant ?844A/G with childhood obesity and biomarkers of obesity such as weight, body mass index (BMI), BMI Z-Score, and adipocyte fatty acid-binding protein, along with a tendency toward significance with insulin resistance biomarkers. In addition, CAT erythrocyte activity was found to be significantly lower in obese children, and it was significantly correlated with obesity and insulin resistance biomarkers. No association was found between erythrocyte CAT activity and the SNP ?844A/G. However, further in vitro and in vivo studies are needed to fully understand the role of CAT activity and SNPs in the development of insulin resistance in the setting of obesity. We hypothesize that CAT plays a role in early metabolic complications of obesity. Antioxid. Redox Signal. 19, 1970–1975. PMID:23641975

  13. Novel insights in mammalian catalase heme maturation: Effect of NO and thioredoxin-1.

    PubMed

    Chakravarti, Ritu; Gupta, Karishma; Majors, Alana; Ruple, Lisa; Aronica, Mark; Stuehr, Dennis J

    2015-05-01

    Catalase is a tetrameric heme-containing enzyme with essential antioxidant functions in biology. Multiple factors including nitric oxide (NO) have been shown to attenuate its activity. However, the possible impact of NO in relation to the maturation of active catalase, including its heme acquisition and tetramer formation, has not been investigated. We found that NO attenuates heme insertion into catalase in both short-term and long-term incubations. The NO inhibition in catalase heme incorporation was associated with defective oligomerization of catalase, such that inactive catalase monomers and dimers accumulated in place of the mature tetrameric enzyme. We also found that GAPDH plays a key role in mediating these NO effects on the structure and activity of catalase. Moreover, the NO sensitivity of catalase maturation could be altered up or down by manipulating the cellular expression level or activity of thioredoxin-1, a known protein-SNO denitrosylase enzyme. In a mouse model of allergic inflammatory asthma, we found that lungs from allergen-challenged mice contained a greater percentage of dimeric catalase relative to tetrameric catalase in the unchallenged control, suggesting that the mechanisms described here are in play in the allergic asthma model. Together, our study shows how maturation of active catalase can be influenced by NO, S-nitrosylated GAPDH, and thioredoxin-1, and how maturation may become compromised in inflammatory conditions such as asthma. PMID:25659933

  14. Cloning and Genetic Characterization ofHelicobacter pylori Catalase and Construction of a Catalase-Deficient Mutant Strain

    Microsoft Academic Search

    STEFAN ODENBREIT; BJORN WIELAND; ANDRAINER HAAS

    1996-01-01

    The N-terminal sequence of a protein, originally described as an adhesin ofHelicobacter pylori, was used in an oligonucleotide-based screening procedure of anH. pyloriplasmid library inEscherichia coli. Five indepen- dent plasmid clones were isolated, all mapping to the same chromosomal region and encoding the H. pylori catalase. The gene, designatedkatA, comprises 1,518 nucleotides and encodes a putative protein of 505 amino

  15. Rapid upregulation of heart antioxidant enzymes during arousal from estivation in the Giant African snail (Achatina fulica).

    PubMed

    Salway, Kurtis D; Tattersall, Glenn J; Stuart, Jeffrey A

    2010-11-01

    Estivation is an adaptive response to environments characterized by elevated temperatures and desiccative stress, as may occur during summer dry seasons. Similar to diapause and hibernation, it is characterized by low levels of activity, a drastically suppressed metabolic rate and enhanced stress resistance. We tested the hypothesis that Achatina fulica, a pulmonate land snail, enhances stress resistance during estivation and/or arousal by upregulating intracellular antioxidant defenses in the heart, kidney, hepatopancreas and foot tissues. No statistically significant changes in mitochondrial or cytosolic superoxide dismutase levels or activities, or glutathione peroxidase, glutathione reductase or catalase activities were associated with estivation in any tissue, however. In contrast, during arousal from estivation, activities of several antioxidant enzymes increased in heart, hepatopancreas and foot. In heart, a rapid increase in MnSOD protein levels was observed that peaked at 2h post arousal, but no such change was observed in CuZnSOD protein levels. Glutathione peroxidase activity was upregulated at 1h post arousal and remained elevated until 8h post arousal in heart tissue. Glutathione peroxidase was also upregulated at 24h post arousal in foot tissue. Glutathione reductase activity was upregulated at 4h post arousal in heart and foot tissues whereas catalase activity showed no changes. Markers of lipid peroxidation and protein damage revealed no significant increases during estivation or arousal. Therefore, antioxidant enzymes may play a role in oxidative stress defense specifically during arousal from estivation in A. fulica. PMID:20621194

  16. Purification and characterization of catalase from marine bacterium Acinetobacter sp. YS0810.

    PubMed

    Fu, Xinhua; Wang, Wei; Hao, Jianhua; Zhu, Xianglin; Sun, Mi

    2014-01-01

    The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT) was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability. PMID:25045672

  17. Purification and Characterization of Catalase from Marine Bacterium Acinetobacter sp. YS0810

    PubMed Central

    Fu, Xinhua; Wang, Wei; Hao, Jianhua; Zhu, Xianglin; Sun, Mi

    2014-01-01

    The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT) was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256?kDa. It showed a Soret peak at 405?nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability. PMID:25045672

  18. Catalase activity of different Candida species after exposition to specific antiserum

    PubMed Central

    Miyasaka, Natália R.S.; Unterkircher, Carmelinda S.; Shimizu, Mario T.

    2008-01-01

    Antisera were developed in rabbits after challenge with intracellular antigens of Candida albicans, C. tropicalis and C. parapsilosis. Microorganism catalase has been correlated with virulence, resistance to drugs and immunogenicity. The intracellular catalase is consistently present in strains of Candida and in this paper, the enzyme activity was analysed by PAGE after exposition to antisera. The catalases of C. albicans, C. parapsilosis and C. tropicalis were immunogenic and differed in their binding to specific antibodies raised in rabbits. Tests of cross-reactivity between different Candida species showed that when antiserum from C. albicans immunized rabbit was incubated with intracellular extracts of these three Candida species, the catalases activities were abolished. However, the antisera from C. parapsilosis or C. tropicalis immunized rabbits did not affect the catalase activity of C. albicans; the enzyme of C. albicans was inactivated only by the antiserum to the catalase of own C. albicans. The antiserum to the catalase of C. tropicalis was species-specific and did not cross-react with catalases of C. albicans and C. parapsilosis. The activities of Aspergillus niger and bovine catalases were not affected by the antiserum from any Candida immunized rabbits. This report is a preliminary study of specific antisera that react against intracellular catalase of Candida sp. and neutralize the enzymatic activity. Further study is necessary to develop species-specific antibody once differences in the susceptibility of the Candida species to commonly used antifungal drugs make identification to the species level important. PMID:24031174

  19. Catalase-negative peroxisomes: transient appearance in rat hepatocytes during liver regeneration after partial hepatectomy.

    PubMed Central

    Oikawa, I.; Novikoff, P. M.

    1995-01-01

    Using light microscopy enzyme cytochemistry to localize catalase activity in peroxisomes, a population of peroxisome-negative hepatocytes was detected in livers of rats during liver regeneration induced by two-thirds partial hepatectomy. However, examination by electron microscopy revealed that this population of hepatocytes contained peroxisomes with a delimiting membrane and a nucleoid, but no cytochemically demonstrable catalase activity within their matrix. Regenerating livers 6, 18, 24, 36, 48 and 72 hours, and 1 week after partial hepatectomy showed hepatocytes without catalase activity. However, their numbers varied, with the most numerous appearing at 24 hours after partial hepatectomy. Mitosis of catalase-negative hepatocytes were seen along with mitosis of hepatocytes containing the normal complement of catalase-positive peroxisomes. The catalase-negative hepatocytes did not show evidence of apoptosis or necrotic cell death. Lysosomal acid phosphatase activity and bile canalicular ATPase activity were present in hepatocytes with catalase-negative peroxisomes. Another population of hepatocytes with a small number of catalase-positive peroxisomes appeared and were more numerous at 36 hours after partial hepatectomy; ultrastructurally, these hepatocytes contained both catalase-negative peroxisomes, which appeared to undergo dissolution, and catalase-positive peroxisomes, which were smaller in size. After complete restoration of the liver, all hepatocytes displayed essentially uniform numbers of catalase-positive peroxisomes. These studies indicated that during liver regeneration there is a transient loss of catalase in peroxisomes of some hepatocytes. These cells proliferate and with time acquire new catalase-positive peroxisomes. The observations are discussed in relation to peroxisome biogenesis, hepatocellular carcinogenesis, and oxidative stress during liver regeneration. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:7887449

  20. Endothelin-1 stimulates catalase activity through the PKC?-mediated phosphorylation of serine 167.

    PubMed

    Rafikov, Ruslan; Kumar, Sanjiv; Aggarwal, Saurabh; Hou, Yali; Kangath, Archana; Pardo, Daniel; Fineman, Jeffrey R; Black, Stephen M

    2014-02-01

    Our previous studies have shown that endothelin-1 (ET-1) stimulates catalase activity in endothelial cells and in lambs with acute increases in pulmonary blood flow (PBF), without altering gene expression. The purpose of this study was to investigate the molecular mechanism by which this occurs. Exposing pulmonary arterial endothelial cells to ET-1 increased catalase activity and decreased cellular hydrogen peroxide (H2O2) levels. These changes correlated with an increase in serine-phosphorylated catalase. Using the inhibitory peptide ?V1.1, this phosphorylation was shown to be protein kinase C? (PKC?) dependent. Mass spectrometry identified serine 167 as the phosphorylation site. Site-directed mutagenesis was used to generate a phospho-mimic (S167D) catalase. Activity assays using recombinant protein purified from Escherichia coli or transiently transfected COS-7 cells demonstrated that S167D catalase had an increased ability to degrade H2O2 compared to the wild-type enzyme. Using a phospho-specific antibody, we were able to verify that pS167 catalase levels are modulated in lambs with acute increases in PBF in the presence and absence of the ET receptor antagonist tezosentan. S167 is located on the dimeric interface, suggesting it could be involved in regulating the formation of catalase tetramers. To evaluate this possibility we utilized analytical gel filtration to examine the multimeric structure of recombinant wild-type and S167D catalase. We found that recombinant wild-type catalase was present as a mixture of monomers and dimers, whereas S167D catalase was primarily tetrameric. Further, the incubation of wild-type catalase with PKC? was sufficient to convert wild-type catalase into a tetrameric structure. In conclusion, this is the first report indicating that the phosphorylation of catalase regulates its multimeric structure and activity. PMID:24211614

  1. (salen)MnIII compounds as nonpeptidyl mimics of catalase. Mechanism-based tuning of catalase activity: a theoretical study.

    PubMed

    Abashkin, Yuri G; Burt, Stanley K

    2005-03-01

    We present the results of the first theoretical investigation of salen-manganese complexes as synthetic catalytic scavengers of hydrogen peroxide molecules that mimic catalase enzymes. Catalase mimics can be used as therapeutic agents against oxidative stress in treatment of many diseases, including Alzheimer's disease, stroke, heart disease, aging, and cancer. A ping-pong mechanism approach has been considered to describe the H2O2 dismutation reaction. The real compounds reacting with a peroxide molecule were utilized in our BP density functional calculations to avoid uncertainties connected with using incomplete models. Part I of the dismutation reaction-converting a peroxide molecule into a water molecule with simultaneous oxidation of the metal atom of the catalyst-can be done quite effectively at the Mn catalytic center. To act as catalytic scavengers of hydrogen peroxide, the oxomanganese salen complexes have to be deoxidized during part II of the dismutation reaction. It has been shown that there are two possible reaction routes for the second part of the dismutation reaction: the top and the side substrate approach routes. Our results suggest that the catalyst could be at least temporarily deactivated (poisoned) in the side approach reaction route due to the formation of a kinetically stable intermediate. Overall, the side approach reaction route for the catalyst recovery is the bottleneck for the whole dismutation process. On the basis of the detailed knowledge of the mode of action of the (salen)MnIII catalase mimics, we suggest and rationalize structural changes of the catalyst that should lead to better therapeutic properties. The available experimental data support our conclusions. Our findings on the reaction dismutation mechanism could be the starting point for further improvement of salen-manganese complexes as synthetic catalytic scavengers of reactive oxygen species. PMID:15732983

  2. A gasometric method to determine erythrocyte catalase activity.

    PubMed

    Siqueira, A J; Remião, J O; Azevedo, A M; Azambuja, C R

    1999-09-01

    We describe a new gasometric method to determine erythrocyte catalase activity by the measurement of the volume of oxygen produced as a result of hydrogen peroxide decomposition in a system where enzyme and substrate are separated in a special reaction test tube connected to a manometer and the reagents are mixed with a motor-driven stirrer. The position of the reagents in the test tube permits the continuous measurement of oxygen evolution from the time of mixing, without the need to stop the reaction by the addition of acid after each incubation time. The enzyme activity is reported as K Hb, i.e., mg hydrogen peroxide decomposed per second per gram of hemoglobin (s-1 g Hb-1). The value obtained for catalase activity in 28 samples of hemolyzed human blood was 94.4 +/- 6.17 mg H2O2 s-1 g Hb-1. The results obtained were precise and consistent, indicating that this rapid, simple and inexpensive method could be useful for research and routine work. PMID:10464384

  3. Stabilization of quaternary structure and activity of bovine liver catalase through encapsulation in liposomes

    Microsoft Academic Search

    Makoto Yoshimoto; Hideyuki Sakamoto; Noriko Yoshimoto; Ryoichi Kuboi; Katsumi Nakao

    2007-01-01

    Bovine liver catalase was encapsulated in an aqueous phase of the phospholipid vesicle (liposome) to improve the stability of its tetrameric structure and activity. The catalase-containing liposomes (CALs) prepared were 30, 50 and 100nm in mean diameters (CAL30, CAL50 and CAL100, respectively). The CAL100 included the types I, II and III based on the amounts of catalase encapsulated. The CAL30,

  4. Abnormality in catalase import into peroxisomes leads to severe neurological disorder.

    PubMed

    Sheikh, F G; Pahan, K; Khan, M; Barbosa, E; Singh, I

    1998-03-17

    Peroxisomal disorders are lethal inherited diseases caused by either defects in peroxisome assembly or dysfunction of single or multiple enzymatic function(s). The peroxisomal matrix proteins are targeted to peroxisomes via the interaction of peroxisomal targeting signal sequences 1 and 2 (PTS1 or PTS2) with their respective cytosolic receptors. We have studied human skin fibroblast cell lines that have multiple peroxisomal dysfunctions with normal packaging of PTS1 and PTS2 signal-containing proteins but lack catalase in peroxisomes. To understand the defect in targeting of catalase to peroxisomes and the loss of multiple enzyme activities, we transfected the mutant cells with normal catalase modified to contain either PTS1 or PTS2 signal sequence. We demonstrate the integrity of these pathways by targeting catalase into peroxisomes via PTS1 or PTS2 pathways. Furthermore, restoration of peroxisomal functions by targeting catalase-SKL protein (a catalase fused to the PTS1 sequence) to peroxisomes indicates that loss of multiple functions may be due to their inactivation by H2O2 or other oxygen species in these catalase-negative peroxisomes. In addition to enzyme activities, targeting of catalase-SKL chimera to peroxisomes also corrected the in situ levels of fatty acids and plasmalogens in these mutant cell lines. In normal fibroblasts treated with aminotriazole to inhibit catalase, we found that peroxisomal functions were inhibited to the level found in mutant cells, an observation that supports the conclusion that multiple peroxisomal enzyme defects in these patients are caused by H2O2 toxicity in catalase-negative peroxisomes. Moreover, targeting of catalase to peroxisomes via PTS1 and PTS2 pathways in these mutant cell lines suggests that there is another pathway for catalase import into peroxisomes and that an abnormality in this pathway manifests as a peroxisomal disease. PMID:9501198

  5. Catalase A from Botrytis cinerea is not expressed during infection on tomato leaves

    Microsoft Academic Search

    C. J. B. van der Vlugt-Bergmans; C. A. M. Wagemakers; D. C. T. Dees; J. A. L. van Kan

    1997-01-01

    Catalase mediates the enzymatic breakdown of hydrogen peroxide to water and molecular oxygen. During the infection of broad bean (Vicia faba) byBotrytis cinereathe release of hydrogen peroxide by fungal oxidase activity was proposed to facilitate penetration by the pathogen. Catalase activity might play a role in protecting the fungus against the damaging effects of hydrogen peroxide.A cDNA clone encoding catalase

  6. Adaptive response of antioxidant enzymes to catalase inhibition by aminotriazole in goldfish liver and kidney

    Microsoft Academic Search

    Tetyana V. Bagnyukova; Kenneth B. Storey; Volodymyr I. Lushchak

    2005-01-01

    This study was undertaken to clarify the physiological role of catalase in the maintenance of pro\\/antioxidant balance in goldfish tissues by inhibiting the enzyme in vivo with 3-amino 1,2,4-triazole. Intraperitoneal injection of aminotriazole (0.5 mg\\/g wet mass) caused a decrease in liver catalase activity by 83% after 24 h that was sustained after 168 h post-injection. In kidney catalase activity

  7. [Search for micromycetes--producers extracellular catalase and study of conditions of its synthesis].

    PubMed

    Kurakov, A V; Kupletskaia, M B; Skrynnikova, E V; Somova, N G

    2001-01-01

    Production of extracellular catalase by microscopic mycelial fungi (255 strains) belonging to different taxonomic groups was studied. Producers of extracellular catalase were found among fungi of the genera Penicillium, Talaromyces and Aspergillus. Strains of the genus Penicillium were the most active producers. The formation of catalase depended on the initial pH, carbon and nitrogen sources and their ratio, and the content of microelements in the medium. The yield of extracellular catalase produced by the strains selected (P. chrysogenum, P. funiculosum, P. pinophilum, and P. minioluteum) was not less than 400-1400 U per ml culture liquid. PMID:11234408

  8. Layer-by-layer self-assembly immobilization of catalases on wool fabrics.

    PubMed

    Liu, J; Wang, Q; Fan, X R; Sun, X J; Huang, P H

    2013-04-01

    A new immobilization strategy of catalases on natural fibers was reported in this paper. Catalase (CAT) from Bacillus subtilis was assembled into multiple layers together with poly(diallyldimethylammonium chloride) (PDDA) on wool fabrics via layer-by-layer (LBL) electrostatic self-assembly deposition. The mechanism and structural evaluation of LBL electrostatic self-assembly were studied in terms of scanning electron microscopy (SEM), surface zeta potential, and apparent color depth (K/S). The SEM pictures showed obvious deposits absorbed on the wool surfaces after LBL self-assembly. The surface zeta potential and dyeing depth of CAT/PDDA-assembled wool fabrics presented a regular layer-by-layer alternating trend along with the change of deposited materials, revealing the multilayer structure of the wool fiber immobilized catalases. The V(max) values were found to be 2,500±238 U/mg protein for the free catalase and 1,000±102 U/mg protein for the immobilized catalase. The K(m) value of free catalase (11.25±2.3 mM) was found to be lower than that of the immobilized catalase (222.2±36.5 mM). The immobilized catalase remained high enzymatic activity and showed a measureable amount of reusability, which proved that LBL electrostatic self-assembly deposition is a promising approach to immobilize catalases. PMID:23420488

  9. Temporal Variation for the Expression of Catalase in DROSOPHILA MELANOGASTER: Correlations between Rates of Enzyme Synthesis and Levels of Translatable Catalase-Messenger RNA

    PubMed Central

    Bewley, Glenn C.; Mackay, William J.; Cook, Julia L.

    1986-01-01

    Two variants that alter the temporal expression of catalase have been isolated from a set of third chromosome substitution lines. Each variant has been mapped to a cytogenetic interval flanked by the visible markers st (3-44.0) and cu (3-50.0) at a map position of 47.0, which is within or near the interval 75D-76A previously identified as containing the catalase structural gene on the bases of dosage responses to segmental aneuploidy. Each variant operates by modulating the rate of enzyme synthesis and the level of translatable catalase-mRNA. PMID:3091448

  10. Soluble epoxide hydrolase contamination of specific catalase preparations inhibits epoxyeicosatrienoic acid vasodilation of rat renal arterioles

    PubMed Central

    Olson, Lauren; Harder, Adam; Isbell, Marilyn; Imig, John D.; Gutterman, David D.; Falck, J. R.; Campbell, William B.

    2011-01-01

    Cytochrome P-450 metabolites of arachidonic acid, the epoxyeicosatrienoic acids (EETs) and hydrogen peroxide (H2O2), are important signaling molecules in the kidney. In renal arteries, EETs cause vasodilation whereas H2O2 causes vasoconstriction. To determine the physiological contribution of H2O2, catalase is used to inactivate H2O2. However, the consequence of catalase action on EET vascular activity has not been determined. In rat renal afferent arterioles, 14,15-EET caused concentration-related dilations that were inhibited by Sigma bovine liver (SBL) catalase (1,000 U/ml) but not Calbiochem bovine liver (CBL) catalase (1,000 U/ml). SBL catalase inhibition was reversed by the soluble epoxide hydrolase (sEH) inhibitor tAUCB (1 ?M). In 14,15-EET incubations, SBL catalase caused a concentration-related increase in a polar metabolite. Using mass spectrometry, the metabolite was identified as 14,15-dihydroxyeicosatrienoic acid (14,15-DHET), the inactive sEH metabolite. 14,15-EET hydrolysis was not altered by the catalase inhibitor 3-amino-1,2,4-triazole (3-ATZ; 10–50 mM), but was abolished by the sEH inhibitor BIRD-0826 (1–10 ?M). SBL catalase EET hydrolysis showed a regioisomer preference with greatest hydrolysis of 14,15-EET followed by 11,12-, 8,9- and 5,6-EET (Vmax = 0.54 ± 0.07, 0.23 ± 0.06, 0.18 ± 0.01 and 0.08 ± 0.02 ng DHET·U catalase?1·min?1, respectively). Of five different catalase preparations assayed, EET hydrolysis was observed with two Sigma liver catalases. These preparations had low specific catalase activity and positive sEH expression. Mass spectrometric analysis of the SBL catalase identified peptide fragments matching bovine sEH. Collectively, these data indicate that catalase does not affect EET-mediated dilation of renal arterioles. However, some commercial catalase preparations are contaminated with sEH, and these contaminated preparations diminish the biological activity of H2O2 and EETs. PMID:21753077

  11. Overexpression of Catalase in Vascular Smooth Muscle Cells Prevents the Formation of Abdominal Aortic Aneurysms

    PubMed Central

    Parastatidis, Ioannis; Weiss, Daiana; Joseph, Giji; Taylor, W Robert

    2013-01-01

    Objective Elevated levels of oxidative stress have been reported in abdominal aortic aneurysms (AAA), but which reactive oxygen species (ROS) promotes the development of AAA remains unclear. Here we investigate the effect of the hydrogen peroxide (H2O2) degrading enzyme catalase on the formation of AAA. Approach and Results AAA were induced with the application of calcium chloride (CaCl2) on mouse infrarenal aortas. The administration of PEG-catalase, but not saline, attenuated the loss of tunica media and protected against AAA formation (0.91±0.1 mm vs. 0.76±0.09 mm). Similarly, in a transgenic mouse model, catalase over-expression in the vascular smooth muscle cells (VSMC) preserved the thickness of tunica media and inhibited aortic dilatation by 50% (0.85±0.14 mm vs. 0.57±0.08 mm). Further studies showed that injury with CaCl2 decreased catalase expression and activity in the aortic wall. Pharmacologic administration or genetic over-expression of catalase restored catalase activity and subsequently decreased matrix metalloproteinase activity. In addition, a profound reduction in inflammatory markers and VSMC apoptosis was evident in aortas of catalase over-expressing mice. Interestingly, as opposed to infusion of PEG-catalase, chronic over-expression of catalase in VSMC did not alter the total aortic H2O2 levels. Conclusions The data suggest that a reduction in aortic wall catalase activity can predispose to AAA formation. Restoration of catalase activity in the vascular wall enhances aortic VSMC survival and prevents AAA formation primarily through modulation of matrix metalloproteinase activity. PMID:23950141

  12. EPR polarization studies on Mn catalase from Lactobacillus plantarum.

    PubMed

    Meier, A E; Whittaker, M M; Whittaker, J W

    1996-01-01

    The binuclear manganese active site of Mn catalase catalyzes redox disproportionation of hydrogen peroxide, forming dioxygen and water. We report here multifrequency EPR and microwave polarization studies of the catalytically active homovalent Mn2+ complex of Lactobacillus plantarum Mn catalase, resolving spectra from each of the thermally accessible multiplet states of the coupled complex by multivariate methods. The experimental spectra have been simulated using computational approaches for the binuclear cluster to predict both intensity and polarization for arbitrary values of the ground state parameters. These two spectroscopic properties define the nature of the ground state wavefunctions and so serve as a sensitive and quantitative measure of the inter-ion interactions in the reduced complex. Interpretation of the spectra in terms of a pair Hamiltonian that includes Heisenberg exchange, dipolar, single site zero field splitting, and Zeeman perturbations leads to the most complete ground state description of the active site metal centers. The results of this spectroscopic analysis support a picture of two high spin ions weakly coupled by exchange interactions (J = 40 cm-1) with relatively small dipole-dipole coupling and single site zero field splittings for the ligand-free reduced enzyme. The coupling between fluoride binding and protonation of the complex has been demonstrated by proton uptake studies. The binding of two fluoride ions in the active site dramatically changes the pair spectra, reflecting a substantially reduced J-coupling (J = 10.5 cm-1) that must be a consequence of perturbation of the bridging ligands. Anion binding to the binuclear Mn complex appears to result in poisoning of the active site by protons, possibly associated with insertion of fluoride into bridging positions of the dimanganese core. PMID:8555195

  13. Stability of catalase and its role in lipid oxidation in beef muscle

    E-print Network

    Pradhan, Abhijeet Amar

    1997-01-01

    of the muscle fiber matrix containing the membranal lipids in many studies conducted on meat lipid oxidation mechanisms, a significant loss (58-64% on a wet weight basis) of catalase activity occurred, presumably due to the dissolution of catalase into the wash...

  14. Effect of nitrate and incubation conditions on the production of catalase and nitrate reductase by staphylococci

    Microsoft Academic Search

    R Talon; D Walter; S Chartier; C Barrière; M. C Montel

    1999-01-01

    The objective of this work was to study the production of catalase and nitrate reductase by staphylococci in order to understand their role in lipid oxidation during sausage manufacturing. Catalase and nitrate reductase were measured in resting cells and supernatants of staphylococci grown in different conditions. All staphylococci (except S. warneri) synthetized nitrate reductase. In static condition, the synthesis was

  15. CHARACTERIZATION OF CATALASE ACTIVITIES IN A ROOT-CLEANING ISOLATE OF PSEUDOMONAS PUTIDA

    EPA Science Inventory

    Psuedomonas putida, a saprophytic root-colonizing bacterium, produces multiple forms of catalase Catalase A which increases in specific activity during growth phase and after treatment with H2O2, is located in the and is inhibited by 3-amino-1,2-4-triazole, EDTA, and cyanide, but...

  16. Changes in Catalase Activity and Its Thermolability in Liver and Kidneys of Ageing Male Garden Lizard

    Microsoft Academic Search

    B. S. Jena; B. K. Patnaik

    1992-01-01

    Catalase activity in liver and kidneys of male garden lizards remained unchanged during maturation, but showed an increase during ageing. Instead of inactivating catalase, thermal treatment at 60 ± 1 ° C caused a marginal increase in enzyme activity in the liver of middle-aged and kidneys of young lizards with no significant effect in old counterparts. Increase in basal enzyme

  17. Studies on the effect of peroxisomicine on catalase activity in albino mice

    Microsoft Academic Search

    Myrthala Moreno-Sepúlveda; Rigoberto Vargas-Zapata; Raquel Ballesteros-Elizondo; Alfredo Piñeyro-López; Julio Sepúlveda-Saavedra

    1997-01-01

    Peroxisomicine is a toxic compound isolated from plants of the genus Karwinskia (Rhamnaceae). This toxin produces irreversible and selective damage to the peroxisomes of yeast cells in vivo. Peroxisomicine also inhibits catalase activity in vitro, when using purified enzyme. This paper reports on the effect of peroxisomicine on liver catalase in tissue fragments, in situ, as well as in mice

  18. Lead-induced catalase activity differentially modulates behaviors induced by short-chain alcohols

    Microsoft Academic Search

    M. Correa; M. Pascual; C. Sanchis-Segura; C. Guerri; C. M. G. Aragon

    2005-01-01

    Acute lead administration produces a transient increase in brain catalase activity. This effect of lead has been used to assess the involvement of brain ethanol metabolism, and therefore centrally formed acetaldehyde, in the behavioral actions of ethanol. In mice, catalase is involved in ethanol and methanol metabolism, but not in the metabolism of other alcohols such as l-propanol or tert-butanol.

  19. Tumor Necrosis Factor\\/Cachectin Decreases Catalase Activity of Rat Liver1

    Microsoft Academic Search

    Walid G. Yasmineh; Janet L. Parkin; I. Caspers; Athanasios Theologides

    Tumor bearing hosts and animals treated with endotoxin commonly show a decrease in the catalase activity of the liver and kidney. Since tumor necrosis factor (TNF)\\/cachectin may play a significant role in these conditions, we investigated its effects on the catalatic and peroxi- datic activity of catalase in the liver and kidney of the rat. The activities of glucose-6-phosphate dehydrogenase

  20. Catalase depression in malignant liver from chickens with myeloblastosis and Marek's disease

    Microsoft Academic Search

    D L Williams-Smith; L N Payne; S J Wyard

    1984-01-01

    In rapidly frozen livers from chickens affected with myeloblastosis and Marek's disease and from unaffected control birds there exists a strong correlation between catalase activity and catalase Electron Paramagnetic Resonance (EPR) signal intensities. The diseased chickens had activities and signals reduced to as little as 10% of control values. There were no changes in the EPR parameters in diseased liver

  1. Catalase depression in malignant liver from chickens with myeloblastosis and Marek's disease.

    PubMed

    Williams-Smith, D L; Payne, L N; Wyard, S J

    1984-09-01

    In rapidly frozen livers from chickens affected with myeloblastosis and Marek's disease and from unaffected control birds there exists a strong correlation between catalase activity and catalase Electron Paramagnetic Resonance (EPR) signal intensities. The diseased chickens had activities and signals reduced to as little as 10% of control values. There were no changes in the EPR parameters in diseased liver and the data support the hypothesis that the lowering in activity is due to lowered catalase levels rather than to catalase inhibition. The rate of transformation of catalase to catalase-formate in liver was studied by freeze-clamping liver in anaesthetised chickens, then warming to 37 degrees for 1 or 2 minutes anaerobiosis, and then refreezing. The only difference of significance in this transformation between diseased and normal livers was the greater percentage of total catalase present as catalase-formate (approximately + 15%) in aerobic diseased liver, which may indicate a lowered production of hydrogen peroxide, relative to formate, in these livers. The rate of transformation was far faster in chickens (t1/2 less than 1 min) than in the rat (t1/2 = 7.7 min). PMID:6087870

  2. BIOLOGY OF HONEYBEE SPERMATOZOA. 3. EFFECT OF AMINO ACIDS AND CATALASE

    E-print Network

    Paris-Sud XI, Université de

    BIOLOGY OF HONEYBEE SPERMATOZOA. 3. EFFECT OF AMINO ACIDS AND CATALASE ON RESPIRATION AS MEASURED.R.G. SUMMARY The addition of exogenous amino acids such as L-lysine, L-arginine, L-glutamic acid and enzyme the earlier view that these amino acids and catalase has beneficial effect on motility and survival

  3. CATALASE AND SUPEROXIDE DISMUTASE OF ROOT-COLONIZING SAPROPHYTIC FLUORESCENT PSEUDOMONADS

    EPA Science Inventory

    Root-colonizing, saprophytic fluorescent pseudomonads of the Pseudomonas putida-P. fluorescens group express similar levels of catalase and superoxide dismutase activities during growth on a sucrose- and amino acid-rich medium. ncreased specific activities of catalase but not sup...

  4. Catalase in Plodia interpunctella I. Genetic control and enzymatic patterns during development

    Microsoft Academic Search

    M. S. Lampropoulou; H. Gelti-Douka

    1977-01-01

    Three electrophoretic patterns of catalase were demonstrated in the adults of the Indian Meal Moth Plodia interpunctella (Hüb) (Lepidoptera: Phycitidae). All the types gave only single bands of catalase activity, which were distinguishable on the gel by mobility. Evidence that the variation between these patterns is controlled by a single sex linked gene with two codominant alleles, was obtained from

  5. Catalase from the white shrimp Penaeus ( Litopenaeus) vannamei: molecular cloning and protein detection

    Microsoft Academic Search

    Olga L. Tavares-Sánchez; Gracia A. Gómez-Anduro; Ximena Felipe-Ortega; Maria A. Islas-Osuna; Rogerio R. Sotelo-Mundo; Carolina Barillas-Mury; Gloria Yepiz-Plascencia

    2004-01-01

    Catalase is an antioxidant enzyme that plays a very important role in the protection against oxidative damage by breaking down hydrogen peroxide. It is a very highly conserved enzyme that has been identified from numerous species including bacteria, fungi, plants and animals, but the information about catalase in crustaceans is very limited. A cDNA containing the complete coding sequence for

  6. Inhibition of Catalase by Tea Catechins in Free and Cellular State: A Biophysical Approach

    PubMed Central

    Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

    2014-01-01

    Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (?)-epigallocatechin gallate (EGCG) and (?)-epicatechin gallate (ECG) with catalase were observed to be 2.27×106 M?1 and 1.66×106 M?1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of ?-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition. PMID:25025898

  7. Effect of nitrate and incubation conditions on the production of catalase and nitrate reductase by staphylococci.

    PubMed

    Talon, R; Walter, D; Chartier, S; Barrière, C; Montel, M C

    1999-11-01

    The objective of this work was to study the production of catalase and nitrate reductase by staphylococci in order to understand their role in lipid oxidation during sausage manufacturing. Catalase and nitrate reductase were measured in resting cells and supernatants of staphylococci grown in different conditions. All staphylococci (except S. warneri) synthetized nitrate reductase. In static condition, the synthesis was maximal during exponential growth phase, whereas in shaking condition, the synthesis was maximal at the beginning of stationary phase. The production of nitrate reductase was increased in presence of nitrate, this effect was particularly important for the two S. carnosus strains which exhibited the highest activity. For all staphylococci, the production of catalase was maximal at the end of the exponential growth phase. The lowest amount of catalase was produced by S. warneri and the highest by S. carnosus. Only S. xylosus 873 and S. saprophyticus 852 released high amounts of catalase in the supernatant growth. Staphylococci produced higher amounts of catalase in shaking conditions. Addition of nitrate in the growth media favoured the synthesis of catalase, with a pronounced effect for S. carnosus. Nitrate also favoured the release of catalase. PMID:10573391

  8. Carboxymethyl starch: Chitosan monolithic matrices containing diamine oxidase and catalase for intestinal delivery.

    PubMed

    Calinescu, Carmen; Mondovi, Bruno; Federico, Rodolfo; Ispas-Szabo, Pompilia; Mateescu, Mircea Alexandru

    2012-05-30

    The capacity of carboxymethyl starch (CMS):Chitosan monolithic tablets to protect diamine oxidase and/or catalase therapeutic enzymes against simulated gastric fluid (SGF) and to control their delivery in simulated intestinal fluid (SIF) was investigated. Enzyme formulations loaded with grass pea seedlings diamine oxidase (PSDAO) vegetal extract, catalase, or PSDAO associated to catalase, were obtained by direct compression. The CMS:Chitosan (1:1) matrix afforded a good gastric protection to PSDAO and to catalase, when each enzyme was formulated separately. Variable amounts of DAO were delivered in the SIF containing pancreatin, with maximal release reached at about 8h, a time convenient for tablets to attain the colon. Up to 50% of the initial enzymatic activity of catalase formulated with CMS:Chitosan was found after 8 h in SIF. For the CMS:Chitosan tablets of bi-enzymatic formulations containing PSDAO:Catalase, the releases of DAO and of catalase were synchronized. The hydrogen peroxide (product of DAO activity) was decomposed by the catalase liberated in the same SIF environment. The proposed formulations could allow novel therapeutic approaches for the treatment of inflammatory bowel diseases, intestinal cancers or pseudo-allergic reactions. PMID:22402476

  9. A simple method of catalase purification for the undergraduate experimental course.

    PubMed

    Chen, Qian; Cheng, Meng; Wang, Yinnan; Yao, Ming; Chen, Yongchun; Gao, Yuan; Ding, Wenyuan

    2015-02-01

    Catalase is a characteristic enzyme of peroxisomes, of which it is the most abundant protein. This enzyme serves as a typical example of a peroxisomal enzyme and is important in the teaching of biochemistry and molecular biology. Although there is substantial information regarding catalase purification, purifying catalase for the junior?grade undergraduate experimental course face challenges in obtaining materials and increasingly expensive purification equipment. This study presents a simple method for the purification of mouse liver catalase using ethanol?chloroform treatment, sodium sulfate fractionation, dialysis and Sephadex G?200 gel filtration chromatography. Catalase was purified 31.8?fold with an 18.3% yield. The advantages of this method were its low operating environment requirements, simple procedure and reduced cost. Furthermore, the method was designed to improve students' comprehensive ability and manipulative ability and to introduce a sense of innovation in the fields of biochemistry and molecular biology during their junior year. PMID:25352249

  10. Activity of superoxide dismutase and catalase in the bean weevil (Acanthoscelides obtectus) selected for postponed senescence.

    PubMed

    Seslija, D; Blagojevi?, D; Spasi?, M; Tuci?, N

    1999-04-01

    Relationship of superoxide dismutase and catalase activities and aging were tested using bean weevil lines selected for postponed senescence. The beetles of different age (young and old) and mating status (virgin and mated) from the extended longevity lines were compared with their counterparts derived from the short-lived lines for activities of SOD and catalase. The old beetles from the long-lived lines had statistically significant higher activity of SOD than their controls. Although we did not find a significant effect of catalase on longevity, beetles originating from both types of lines exhibited an increased catalase activity during mating processes. In addition, we did observe an increased activity of catalase in one-day-old beetles of the short-lived lines relative to the same-aged individuals of the long-lived lines. PMID:10363786

  11. Manipulation of catalase levels produces altered photosynthesis in transgenic tobacco plants.

    PubMed

    Brisson, L F; Zelitch, I; Havir, E A

    1998-01-01

    Constructs containing the cDNAs encoding the primary leaf catalase in Nicotiana or subunit 1 of cottonseed (Gossypium hirsutum) catalase were introduced in the sense and antisense orientation into the Nicotiana tabacum genome. The N. tabacum leaf cDNA specifically overexpressed CAT-1, the high catalatic [corrected] form, activity. Antisense constructs reduced leaf catalase specific activities from 0.20 to 0.75 times those of wild type (WT), and overexpression constructs increased catalase specific activities from 1.25 to more than 2.0 times those of WT. The NADH-hydroxypyruvate reductase specific activity in transgenic plants was similar to that in WT. The effect of antisense constructs on photorespiration was studied in transgenic plants by measuring the CO2 compensation point (gamma) at a leaf temperature of 38 degrees C. A significant linear increase was observed in gamma with decreasing catalase (at 50% lower catalase activity gamma increased 39%). There was a significant temperature-dependent linear decrease in gamma in transgenic leaves with elevated catalase compared with WT leaves (at 50% higher catalase gamma decreased 17%). At 29 degrees C, gamma also decreased with increasing catalase in transgenic leaves compared with WT leaves, but the trend was not statistically significant. Rates of dark respiration were the same in WT and transgenic leaves. Thus, photorespiratory losses of CO2 were significantly reduced with increasing catalase activities at 38 degrees C, indicating that the stoichiometry of photorespiratory CO2 formation per glycolate oxidized normally increases at higher temperatures because of enhanced peroxidation. PMID:9449845

  12. Loss of catalase activity in Tn1545-induced mutants does not reduce growth of Listeria monocytogenes in vivo.

    PubMed Central

    Leblond-Francillard, M; Gaillard, J L; Berche, P

    1989-01-01

    Two catalase-negative mutants of Listeria monocytogenes were obtained by chromosomal insertions of the conjugative transposon Tn1545. The loss of catalase activity did not reduce the level of virulence of these mutants in mice. Indeed, both mutants were capable of growing in host tissues at the same rate as the parental catalase-positive strain. These results favor the view that catalase does not play a critical role in the resistance of L. monocytogenes to macrophage killing. PMID:2545629

  13. Recovery of a Catalase-Negative Staphylococcus epidermidis Strain in Blood and Urine Cultures from a Patient with Pyelonephritis ?

    PubMed Central

    Kallstrom, George; Chang, Tom; Albertson, Marc; Morilla, Daniel; Fisher, Mark A.; Eberly, Bardwell

    2011-01-01

    This report describes a 60-year-old patient with bilateral nephrolithiasis. A catalase-negative Staphylococcus epidermidis strain was recovered from both urine and blood cultures. Although rare, isolates of catalase-negative Staphylococcus spp., including Staphylococcus aureus, have been reported. Here, we describe the first report of a catalase-negative S. epidermidis strain. PMID:21900516

  14. Identification of Zantedeschia aethiopica Cat1 and Cat2 catalase genes and their expression analysis during spathe senescence and regreening

    Microsoft Academic Search

    Teresa Lino-Neto; Maria Conceição Piques; Cátia Barbeta; Manuel F. Sousa; Rui M. Tavares; Maria Salomé Pais

    2004-01-01

    Plants encode catalase (CAT; EC 1.11.1.6) as multigene families, which may reflect the multiple and diverse roles played by this enzyme. Catalases from higher plants can be subdivided into three distinct types, according to their phylogenetic relationship. However, there is not a specific correlation of phylogeny and function within these groups, as catalases from the same type can play different

  15. Selective sensitization of bacteria to peroxide damage associated with fluoride inhibition of catalase and pseudocatalase.

    PubMed

    Phan, T N; Kirsch, A M; Marquis, R E

    2001-02-01

    Fluoride and sulfide are known inhibitors of heme catalases in acid environments. Staphylococcus aureus H cells were found to be sensitized by fluoride or sulfide to H2O2 killing at acid pH values in the range of 3.5 to 4.0, and catalase activity was reduced concomitantly. In contrast, fluoride had little effect on H2O2 killing of Streptococcus mutans GS-5, which has fluoride-insensitive peroxidase activity, but still is more sensitive to H2O2 than is S. aureus in the absence of fluoride. Fluoride but not sulfide was inhibitory also for the Mn-containing, non-heme pseudocatalase of Lactobacillus plantarum ATCC 14431 over a wide pH range, and this inhibitory effect was reflected in enhanced H2O2 killing in the presence of fluoride. In addition, we found that catalase-positive S. aureus or Neisseria sicca could protect catalase-negative S. mutans against killing by H2O2 in mixed suspensions, but protection was compromised by fluoride or sulfide under acid conditions. Thus, catalase-positive organisms could protect a catalase-negative organism against peroxide damage, but inhibition of catalase reduced protection. These findings are pertinent to the widespread use of fluoride and peroxide in oral health care products. PMID:11169136

  16. The role of catalase-peroxidase secreted by Magnaporthe oryzae during early infection of rice cells.

    PubMed

    Tanabe, Shigeru; Ishii-Minami, Naoko; Saitoh, Ken-Ichiro; Otake, Yuko; Kaku, Hanae; Shibuya, Naoto; Nishizawa, Yoko; Minami, Eiichi

    2011-02-01

    The biological role of a secretory catalase of the rice blast fungus Magnaporthe oryzae was studied. The internal amino acid sequences of the partially purified catalase in the culture filtrate enabled us to identify its encoding gene as a catalase-peroxidase gene, CPXB, among four putative genes for catalase or catalase-peroxidase in M. oryzae. Knockout of the gene drastically reduced the level of catalase activity in the culture filtrate and supernatant of conidial suspension (SCS), and increased the sensitivity to exogenously added H?O? compared with control strains, suggesting that CPXB is the major gene encoding the secretory catalase and confers resistance to H?O? in hyphae. In the mutant, the rate of appressoria that induced accumulation of H?O? in epidermal cells of the leaf sheath increased and infection at early stages was delayed; however, the formation of lesions in the leaf blade was not affected compared with the control strain. These phenotypes were complimented by reintroducing the putative coding regions of CPXB driven by a constitutive promoter. These results suggest that CPXB plays a role in fungal defense against H?O? accumulated in epidermal cells of rice at the early stage of infection but not in pathogenicity of M. oryzae. PMID:21043575

  17. Catalase is a key enzyme in seed recovery from ageing during priming.

    PubMed

    Kibinza, Serge; Bazin, Jérémie; Bailly, Christophe; Farrant, Jill M; Corbineau, Françoise; El-Maarouf-Bouteau, Hayat

    2011-09-01

    Ageing induces seed deterioration expressed as the loss of seed vigour and/or viability. Priming treatment, which consists in soaking of seeds in a solution of low water potential, has been shown to reinvigorate aged seeds. We investigate the importance of catalase in oxidation protection during accelerated ageing and repair during subsequent priming treatment of sunflower (Helianthus annuus L.) seeds. Seeds equilibrated to 0.29g H2Og(-1) dry matter (DM) were aged at 35°C for different durations and then primed by incubation for 7 days at 15°C in a solution of polyethylene glycol 8000 at -2MPa. Accelerated ageing affected seed germination and priming treatment reversed partially the ageing effect. The inhibition of catalase by the addition of aminotriazol during priming treatment reduced seed repair indicating that catalase plays a key role in protection and repair systems during ageing. Ageing was associated with H2O2 accumulation as showed by biochemical quantification and CeCl3 staining. Catalase was reduced at the level of gene expression, protein content and affinity. Interestingly, priming induced catalase synthesis by activating expression and translation of the enzyme. Immunocytolocalization of catalase showed that the enzyme co-localized with H2O2 in the cytosol. These results clearly indicate that priming induce the synthesis of catalase which is involved in seed recovery during priming. PMID:21763542

  18. [The catalase inhibitor aminotriazole alleviates acute alcoholic liver injury].

    PubMed

    Ai, Qing; Ge, Pu; Dai, Jie; Liang, Tian-Cai; Yang, Qing; Lin, Ling; Zhang, Li

    2015-02-25

    In this study, the effects of catalase (CAT) inhibitor aminotriazole (ATZ) on alcohol-induced acute liver injury were investigated to explore the potential roles of CAT in alcoholic liver injury. Acute liver injury was induced by intraperitoneal injection of alcohol in Sprague Dawley (SD) rats, and various doses of ATZ (100-400 mg/kg) or vehicle were administered intraperitoneally at 30 min before alcohol exposure. After 24 h of alcohol exposure, the levels of aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in plasma were determined. The degree of hepatic histopathological abnormality was observed by HE staining. The activity of hepatic CAT, hydrogen peroxide (H2O2) level and malondialdehyde (MDA) content in liver tissue were measured by corresponding kits. The levels of tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6) in plasma were determined by ELISA method. The results showed that treatment with ATZ dose-dependently suppressed the elevation of ALT, AST and LDH levels induced by alcohol exposure, and that ATZ alleviated alcohol-induced histopathological alterations. Furthermore, ATZ inhibited the activity of CAT, reduced hepatic levels of H2O2 and MDA in alcohol exposed rats. ATZ also decreased the levels of plasma TNF-? and IL-6 in rats with alcohol exposure. These results indicated that ATZ attenuated alcohol-induced acute liver injury in rats, suggesting that CAT might play important pathological roles in the pathogenesis of alcoholic liver injury. PMID:25672632

  19. Effects of pergolide mesylate on transduction efficiency of PEP-1-catalase protein

    SciTech Connect

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)] [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Lim, Soon Sung [Department of Food Science and Nutrition and RIC Center, Hallym University, Chunchon 200-702 (Korea, Republic of)] [Department of Food Science and Nutrition and RIC Center, Hallym University, Chunchon 200-702 (Korea, Republic of); Kang, Tae-Cheon [Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of)] [Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kwon, Hyeok Yil [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of)] [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Kim, Duk-Soo [Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 330-090 (Korea, Republic of)] [Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 330-090 (Korea, Republic of); Cho, Sung-Woo [Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)] [Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)] [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Hwang, Hyun Sook, E-mail: wazzup@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

    2011-03-18

    Research highlights: {yields} We studied effects of pergolide mesylate (PM) on in vitro and in vivo transduction of PEP-1-catalase. {yields} PEP-1-catatase inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation. {yields} PM enhanced the transduction of PEP-1-catalase into HaCaT cells and skin tissue. {yields} PM increased anti-inflammatory activity of PEP-1-catalase. {yields} PM stimulated therapeutic action of anti-oxidant enzyme catalase in oxidative-related diseases. -- Abstract: The low transduction efficiency of various proteins is an obstacle to their therapeutic application. However, protein transduction domains (PTDs) are well-known for a highly effective tool for exogenous protein delivery to cells. We examined the effects of pergolide mesylate (PM) on the transduction of PEP-1-catalase into HaCaT human keratinocytes and mice skin and on the anti-inflammatory activity of PEP-1-catatase against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation using Western blot and histological analysis. PM enhanced the time- and dose-dependent transduction of PEP-1-catalase into HaCaT cells without affecting the cellular toxicity. In a mouse edema model, PEP-1-catalase inhibited the increased expressions of inflammatory mediators and cytokines such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1{beta}, and tumor necrosis factor-{alpha} induced by TPA. On the other hand, PM alone failed to exert any significant anti-inflammatory effects. However, the anti-inflammatory effect of co-treatment with PEP-1-catalase and PM was more potent than that of PEP-1-catalase alone. Our results indicate that PM may enhance the delivery of PTDs fusion therapeutic proteins to target cells and tissues and has potential to increase their therapeutic effects of such drugs against various diseases.

  20. The regulation of catalase activity by PPAR ? is affected by ?-synuclein

    PubMed Central

    Yakunin, Eugenia; Kisos, Haya; Kulik, Willem; Grigoletto, Jessica; Wanders, Ronald J A; Sharon, Ronit

    2014-01-01

    Objective While evidence for oxidative injury is frequently detected in brains of humans affected by Parkinson's disease (PD) and in relevant animal models, there is uncertainty regarding its cause. We tested the potential role of catalase in the oxidative injury that characterizes PD. Methods Utilizing brains of A53T ?-Syn and ntg mice, and cultured cells, we analyzed catalase activity and expression, and performed biochemical analyses of peroxisomal metabolites. Results Lower catalase expression and lower activity levels were detected in A53T ?-Syn brains and ?-Syn-expressing cells. The effect on catalase activity was independent of disease progression, represented by mouse age and ?-Syn mutation, suggesting a potential physiological function for ?-Syn. Notably, catalase activity and expression were unaffected in brains of mice modeling Alzheimer's disease. Moreover, we found that ?-Syn expression downregulate the peroxisome proliferator-activated receptor (PPAR)?, which controls catalase transcription. Importantly, activation of either PPAR?2, PPAR? or retinoic X receptor eliminated the inhibiting effect of ?-Syn on catalase activity. In addition, activation of these nuclear receptors enhanced the accumulation of soluble ?-Syn oligomers, resulting in a positive association between the degree of soluble ?-Syn oligomers and catalase activity. Of note, a comprehensive biochemical analysis of specific peroxisomal metabolites indicated no signs of dysfunction in specific peroxisomal activities in brains of A53T ?-Syn mice. Interpretation Our results suggest that ?-Syn expression may interfere with the complex and overlapping network of nuclear receptors transcription activation. In result, catalase activity is affected through mechanisms involved in the regulation of soluble ?-Syn oligomers. PMID:25356396

  1. Adsorption Kinetics of Catalase to Thin-Films of Carbon Nanotubes

    PubMed Central

    Felhofer, Jessica L.; Caranto, Jonathan D.; Garcia, Carlos D.

    2010-01-01

    The adsorption conditions used to immobilize catalase onto thin-films of carbon nanotubes were investigated to elucidate the conditions that produced films with maximum amounts of active catalase. The adsorption kinetics were monitored by spectroscopic ellipsometry and the immobilized catalase films were then assayed for catalytic activity. The development of a volumetric optical model used to interpret the ellipsometric data is discussed. According to the results herein discussed, not only the adsorbed amount but also the initial adsorption rates determine the final catalytic activity of the adsorbed layer. The results described in the manuscript have direct implications on the rational design and analytical performance of enzymatic biosensors. PMID:20945910

  2. Cloning and Heterologous Expression of Hematin-Dependent Catalase Produced by Lactobacillus plantarum CNRZ 1228

    PubMed Central

    Abriouel, Hikmate; Herrmann, Anette; Stärke, Joachim; Yousif, Nuha M. K.; Wijaya, Agus; Tauscher, Bernhard; Holzapfel, Wilhelm; Franz, Charles M. A. P.

    2004-01-01

    Lactobacillus plantarum CNRZ 1228 exhibited heme-dependent catalase activity under environmental conditions similar to those encountered during sausage fermentation. The 1,455-bp catalase gene (katL) was cloned and encoded a protein of 484 amino acids. Expression of katL in a heterologous host showed that katL encodes a functional catalase. PCR screening of selected strains of lactic acid bacteria for katL indicated the presence of similar genes in other strains of lactobacilli. PMID:14711694

  3. Klotho upregulation contributes to the neuroprotection of ligustilide in an Alzheimer's disease mouse model.

    PubMed

    Kuang, Xi; Chen, Ya-Shu; Wang, Liang-Fen; Li, Yong-Jie; Liu, Ke; Zhang, Meng-Xue; Li, Ling-Jiao; Chen, Chu; He, Qian; Wang, Yu; Du, Jun-Rong

    2014-01-01

    Klotho, an aging-suppressor gene, encodes a protein that potentially acts as a neuroprotective factor by modulating insulin-like growth factor 1 signaling and oxidative stress. In the present study, we investigated the potential role of Klotho in the therapeutic effect of ligustilide against Alzheimer's disease (AD)-like neuropathologies and memory impairment in aged senescence-accelerated mouse prone-8 (SAMP8) mice. Ligustilide treatment (10 and 40 mg/kg for 8 weeks, intragastrically) in 10-month-old SAMP8 mice reduced memory deficits, amyloid-?(1)-42 accumulation, tau phosphorylation, and neuron loss, increased mitochondrial manganese-superoxide dismutase and catalase expression and activity, and decreased malondialdehyde, protein carbonyl, and 8-hydroxydesoxyguanosine levels in the brain. Ligustilide upregulated Klotho expression in the cerebral choroid plexus and serum, decreased Akt and Forkhead box class O1 phosphorylation. Moreover, ligustilide inhibited the insulin-like growth factor 1 pathway and induced Forkhead box class O1 activation in 293T cells along with Klotho upregulation. An inverse correlation was found between Klotho expression and the AD phenotype, suggesting that Klotho might be a novel therapeutic target for age-related AD, and Klotho upregulation might contribute to the neuroprotective effect of ligustilide against AD. PMID:23973442

  4. High resistance to oxidative damage in the Antarctic midge Belgica antarctica, and developmentally linked expression of genes encoding superoxide dismutase, catalase and heat shock proteins.

    PubMed

    Lopez-Martinez, Giancarlo; Elnitsky, Michael A; Benoit, Joshua B; Lee, Richard E; Denlinger, David L

    2008-08-01

    Intense ultraviolet radiation, coupled with frequent bouts of freezing-thawing and anoxia, have the potential to generate high levels of oxidative stress in Antarctic organisms. In this study, we examined mechanisms used by the Antarctic midge, Belgica antarctica, to counter oxidative stress. We cloned genes encoding two key antioxidant enzymes, superoxide dismutase (SOD) and catalase (Cat), and showed that SOD mRNA was expressed continuously and at very high levels in larvae, but not in adults, while Cat mRNA was expressed in both larvae and adults but at a somewhat reduced level. SOD mRNA was expressed at even higher levels in larvae that were exposed to direct sunlight. Catalase, a small heat shock protein, Hsp70 and Hsp90 mRNAs were also strongly upregulated in response to sunlight. Total antioxidant capacity of the adults was higher than that of the larvae, but levels in both stages of the midge were much higher than observed in a freeze-tolerant, temperate zone insect, the gall fly Eurosta solidaginis. Assays to measure oxidative damage (lipid peroxidation TBARS and carbonyl proteins) demonstrated that the Antarctic midge is highly resistant to oxidative stress. PMID:18625403

  5. Occurrence of High Catalase-containing Acinetobacter in Spacecraft Assembly Facilities

    NASA Astrophysics Data System (ADS)

    McCoy, K. B.; Derecho, I.; La Duc, M. T.; Vaishampayan, P.; Venkateswaran, K. J.; Mogul, R.

    2010-04-01

    In summary, the measurement of high catalase specific activity values for spacecraft-associated Acinetobacter strains is potentially the result of adaptation towards the harsh conditions of the clean rooms and assembly process.

  6. A Simple Method for Demonstrating Enzyme Kinetics Using Catalase from Beef Liver Extract

    NASA Astrophysics Data System (ADS)

    Johnson, Kristin A.

    2000-11-01

    This paper describes a simple visual method of demonstrating enzyme kinetics using beef liver catalase. A catalase solution is obtained by homogenizing beef liver in a phosphate buffer. In the demonstration, filter paper is saturated with beef liver extract and placed into a solution of hydrogen peroxide. The catalase in the extract decomposes the hydrogen peroxide to water and oxygen. Oxygen forms on the filter paper, and the filter paper rises to the top of the beaker. Catalase activity is measured by timing the rise of the enzyme-soaked filter paper to the top of beakers containing different concentrations of hydrogen peroxide. The data are plotted as a Lineweaver-Burk double-reciprocal plot, and the Km and Vmax for the reaction are calculated.

  7. Catalase Activity of Mouse Liver and its Relation to the Condition of the Animal

    Microsoft Academic Search

    K. G. van Senden; J. de Jong

    1960-01-01

    IN papers dealing with methods of determining catalase activity in animal tissue, while dealing with the experimental conditions, usually little attention is paid to the condition of the animal. We have found the latter to be of utmost importance.

  8. Regulation of Cyclo-oxygenase Gene Expression in Rat Smooth Muscle Cells by Catalase

    Microsoft Academic Search

    Gong Chen; Mahine Kamal; Robert Hannon; Timothy D. Warner

    1998-01-01

    We have studied, in detail, the effect of catalase, one of the naturally occurring antioxidant enzymes, on the expression of cyclo-oxygenase (COX) mRNA and protein in rat aortic smooth muscle cells (RASMC). The activity of COX enzyme within the cells was also determined. Catalase either alone or in combination with interleukin-1? (IL-1?) enhanced mRNA and protein expression for cyclo-oxygenase 2

  9. Catalase activity as a potential vital biomarker of fish intoxication by the herbicide aminotriazole

    Microsoft Academic Search

    Olena Yu. Vasylkiv; Olga I. Kubrak; Kenneth B. Storey; Volodymyr I. Lushchak

    2011-01-01

    The objective of this study was to investigate the effects of the herbicide 3-amino-1,2,4-triazole (AMT) on the activities of catalase and lactate dehydrogenase (LDH) in blood (plasma and erythrocytes) and eight solid tissues of goldfish, Carassius auratus. Injection of goldfish with AMT (0.5mg\\/gww AMT in 0.9% NaCl) resulted in a significant decrease in catalase activity 24h post-injection in most tissues

  10. The Effects of Cadmium and Iron on Catalase Activities in Tubifex

    Microsoft Academic Search

    Tao Chen; Arthur Furst; Paul K. Chien

    1994-01-01

    The effects of 1 ?\\/M Cd(II), alone and in combination with several concentrations of Fe(II), were investigated in Tubifex tubifex (a fresh water worm) by the determination of catalase activities in vivo at 6, 12, 24, and 48 h. At 6 h postexposure the catalase activities in all cadmium-exposed groups dropped below control values. At 12 and 24 h the

  11. Impact of sodium cyanide on catalase activity in the freshwater exotic carp, Cyprinus carpio (Linnaeus)

    Microsoft Academic Search

    Muniswamy David; Vadingadu Munaswamy; Ramesh Halappa; Shambangouda R. Marigoudar

    2008-01-01

    The Cyprinus carpio fingerlings on exposure to lethal (1mg\\/L) and sub lethal concentrations (0.066mg\\/L) of sodium cyanide showed inhibition in the activity of catalase. The disruption of catalase activity in freshwater fish, C. carpio is demonstrated in the present study using UV–visible spectrophotometer at 240nm using hydrogen peroxide as a substrate. It suggests toxic effects of sodium cyanide and consequent

  12. Subchronic exposure to high-dose ACE-inhibitor moexipril induces catalase activity in rat liver

    Microsoft Academic Search

    E. Adeghate; M. Y. Hasan; A. S. Ponery; S. M. Nurulain; G. A. Petroianu

    2005-01-01

    The long-term clinical effects of ACE-inhibitors have similarities with those of both fibrates and glitazones, activators\\u000a of peroxisome proliferator activator receptor (PPAR) alpha and gamma, respectively. The antioxidant enzyme catalase, a heme\\u000a protein that degrades hydrogen peroxide, is found at high concentrations in peroxisomes. Catalase activity is one of the recognized\\u000a surrogate markers indicative of PPAR activation in the rat

  13. Peroxynitrite formation and decreased catalase activity in autoimmune MRL-lpr/lpr mice.

    PubMed Central

    Keng, T.; Privalle, C. T.; Gilkeson, G. S.; Weinberg, J. B.

    2000-01-01

    BACKGROUND: (MRL)-lpr/lpr mice spontaneously develop autoimmune disease characterized by arthritis and glomerulonephritis. Nitric oxide is postulated to play a role in the disease pathogenesis, as mice treated with the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (NMMA) show markedly reduced manifestations of the disease. The purpose of this study was to examine the role of peroxynitrite in disease development in MRL-lpr/lpr mice. MATERIALS AND METHODS: We examined kidney extracts from control and MRL-lpr/lpr mice for nitrotyrosine by immunoblot with a rabbit polyclonal anti-nitrotyrosine antibody. Catalase activity was determined spectrophotometrically or by activity staining of native polyacrylamide gels. In some experiments, we studied the ability of peroxynitrite and other agents to modify purified catalase in vitro. RESULTS: Kidney extracts from diseased mice had elevated levels of nitrotyrosine, and decreased levels of catalase activity and protein, relative to control mice. MRL-lpr/lpr mice treated with NMMA in vivo had decreased levels of nitrotyrosine, and demonstrated a partial restoration of both catalase activity and protein levels. Treatment of catalase in vitro with peroxynitrite or tetranitromethane at pH 8.0 resulted in protein nitration and a decrease in catalase activity. 1,3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, also decreased the activity of catalase. CONCLUSIONS: These observations suggest that peroxynitrite formation, with an associated decrease in catalase activity and general decrease in antioxidant enzyme activity, may result in increased levels of hydrogen peroxide and other oxidants that can contribute to the pathogenesis of disease in MRL-lpr/lpr mice. PMID:11071272

  14. Vascular endothelium-specific overexpression of human catalase in cloned pigs

    Microsoft Academic Search

    J. J. Whyte; M. Samuel; E. Mahan; J. Padilla; G. H. Simmons; A. A. Arce-Esquivel; S. B. Bender; K. M. Whitworth; Y. H. Hao; C. N. Murphy; E. M. Walters; R. S. Prather; M. H. Laughlin

    The objective of this study was to develop transgenic Yucatan minipigs that overexpress human catalase (hCat) in an endothelial-specific\\u000a manner. Catalase metabolizes hydrogen peroxide (H2O2), an important regulator of vascular tone that contributes to diseases such as atherosclerosis and preeclampsia. A large\\u000a animal model to study reduced endothelium-derived H2O2 would therefore generate valuable translational data on vascular regulation in health

  15. Possible Role of Catalase in Adaptation to Diving of SemiAquatic Rodents Ondatra zibethica

    Microsoft Academic Search

    O. V. Loshchagin; R. I. Kovalenko; A. D. Nozdrachev; I. N. Yanvareva; B. I. Krivoruchko

    2002-01-01

    Physiological role of catalase in mechanisms of adaptive reactions to hypoxic influences in diving rodents, muskrats Ondatra zibethica, has been investigated. The myocardial tissues were established to be the most resistant to the oxidative stress produced by hypobaric hypoxia-reoxygenation. An intraperitoneal injection of a specific nonreversible catalase inhibitor, 3-amino-1, 2, 4-triazol (3-AT), at a dose of 1 g\\/kg body weight,

  16. Improved growth and viability of lactobacilli in the presence of Bacillus subtilis (natto), catalase, or subtilisin.

    PubMed

    Hosoi, T; Ametani, A; Kiuchi, K; Kaminogawa, S

    2000-10-01

    In an effort to demonstrate the potential usefulness of Bacillus subtilis (natto) as a probiotic, we examined the effect of this organism on the growth of three strains of lactobacilli co-cultured aerobically in vitro. Addition of B. subtilis (natto) to the culture medium resulted in an increase in the number of viable cells of all lactobacilli tested. Since B. subtilis (natto) can produce catalase, which has been reported to exhibit a similar growth-promoting effect on lactobacilli, we also examined the effect of bovine catalase on the growth of Lactobacillus reuteri JCM 1112 and L. acidophilus JCM 1132. Both catalase and B. subtilis (natto) enhanced the growth of L. reuteri JCM 1112, whereas B. subtilis (natto) but not catalase enhanced the growth of L. acidophilus JCM 1132. In a medium containing 0.1 mM hydrogen peroxide, its toxic effect on L. reuteri JCM 1112 was abolished by catalase or B. subtilis (natto). In addition, a serine protease from B. licheniformis, subtilisin, improved the growth and viability of L. reuteri JCM 1112 and L. acidophilus JCM 1132 in the absence of hydrogen peroxide. These results indicate that B. subtilis (natto) enhances the growth and (or) viability of lactobacilli, possibly through production of catalase and subtilisin. PMID:11068675

  17. Increased Expression of Catalase and Superoxide Dismutase 2 Reduces Cone Cell Death in Retinitis Pigmentosa

    PubMed Central

    Usui, Shinichi; Komeima, Keiichi; Lee, Sun Young; Jo, Young-Joon; Ueno, Shinji; Rogers, Brian S; Wu, Zhihao; Shen, Jikui; Lu, Lili; Oveson, Brian C; Rabinovitch, Peter S; Campochiaro, Peter A

    2009-01-01

    Oxidative and nitrosative damage are major contributors to cone cell death in retinitis pigmentosa (RP). In this study, we explored the effects of augmenting components of the endogenous antioxidant defense system in models of RP, rd1, and rd10 mice. Unexpectedly, overexpression of superoxide dismutase 1 (SOD1) in rd1 mice increased oxidative damage and accelerated cone cell death. With an elaborate mating scheme, genetically engineered rd10 mice with either inducible expression of SOD2, Catalase, or both in photoreceptor mitochondria were generated. Littermates with the same genetic background that did not have increased expression of SOD2 nor Catalase provided ideal controls. Coexpression of SOD2 and Catalase, but not either alone, significantly reduced oxidative damage in the retinas of postnatal day (P) 50 rd10 mice as measured by protein carbonyl content. Cone density was significantly greater in P50 rd10 mice with coexpression of SOD2 and Catalase together than rd10 mice that expressed SOD2 or Catalase alone, or expressed neither. Coexpression of SOD2 and Catalase in rd10 mice did not slow rod cell death. These data support the concept of bolstering the endogenous antioxidant defense system as a gene-based treatment strategy for RP, and also indicate that coexpression of multiple components may be needed. PMID:19293779

  18. Milk catalase activity as an indicator of thermization treatments used in the manufacture of cheddar cheese.

    PubMed

    Hirvi, Y; Griffiths, M W

    1998-02-01

    Pilot-scale studies were carried out to determine the effect of different heat treatments on catalase activity during the manufacture and maturation of Cheddar cheese. Three trials were conducted to monitor catalase activity using disk flotation and polarographic methods. Cheese was manufactured from raw milk and from milk that had been treated at 60, 65 and 72 degrees C for 16 s using a high temperature, short time heat exchanger. Catalase activity was also determined in samples of commercial milk and in samples of mild, medium, sharp, and extra sharp Cheddar cheeses obtained from different manufacturers in order to verify that the enzyme could be used as an indicator of the type of heat treatment applied to cheese milk. Catalase activity was present in cheese made from raw milk but was only present at low concentrations in cheese manufactured from thermized milk. However, high catalase activity was observed in commercial samples of sharp and extra sharp Cheddar cheese that was apparently due to the growth of catalase-producing yeasts in the cheese during maturation. PMID:9532488

  19. Redundant Catalases Detoxify Phagocyte Reactive Oxygen and Facilitate Histoplasma capsulatum Pathogenesis

    PubMed Central

    Holbrook, Eric D.; Smolnycki, Katherine A.; Youseff, Brian H.

    2013-01-01

    Histoplasma capsulatum is a respiratory pathogen that infects phagocytic cells. The mechanisms allowing Histoplasma to overcome toxic reactive oxygen molecules produced by the innate immune system are an integral part of Histoplasma's ability to survive during infection. To probe the contribution of Histoplasma catalases in oxidative stress defense, we created and analyzed the virulence defects of mutants lacking CatB and CatP, which are responsible for extracellular and intracellular catalase activities, respectively. Both CatB and CatP protected Histoplasma from peroxide challenge in vitro and from antimicrobial reactive oxygen produced by human neutrophils and activated macrophages. Optimal protection required both catalases, as the survival of a double mutant lacking both CatB and CatP was lower than that of single-catalase-deficient cells. Although CatB contributed to reactive oxygen species defenses in vitro, CatB was dispensable for lung infection and extrapulmonary dissemination in vivo. Loss of CatB from a strain also lacking superoxide dismutase (Sod3) did not further reduce the survival of Histoplasma yeasts. Nevertheless, some catalase function was required for pathogenesis since simultaneous loss of both CatB and CatP attenuated Histoplasma virulence in vivo. These results demonstrate that Histoplasma's dual catalases comprise a system that enables Histoplasma to efficiently overcome the reactive oxygen produced by the innate immune system. PMID:23589579

  20. Reversible adsorption of catalase onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogels.

    PubMed

    Akta? Uygun, Deniz; Uygun, Murat; Akgöl, Sinan; Denizli, Adil

    2015-05-01

    In this presented study, poly(acrylamide-glycidyl methacrylate) [poly(AAm-GMA)] cryogels were synthesized by cryopolymerization technique at sub-zero temperature. Prepared cryogels were then functionalized with iminodiacetic acid (IDA) and chelated with Fe(3+) ions in order produce the metal chelate affinity matrix. Synthesized cryogels were characterized with FTIR, ESEM and EDX analysis, and it was found that the cryogel had sponge like structure with interconnected pores and their pore diameter was about 200?m. Fe(3+) chelated poly(AAm-GMA)-IDA cryogels were used for the adsorption of catalase and optimum adsorption conditions were determined by varying the medium pH, initial catalase concentration, temperature and ionic strength. Maximum catalase adsorption onto Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was found to be 12.99mg/g cryogel at 25°C, by using pH5.0 acetate buffer. Adsorbed catalase was removed from the cryogel by using 1.0M of NaCl solution and desorption yield was found to be 96%. Additionally, reusability profile of the Fe(3+) chelated poly(AAm-GMA)-IDA cryogel was also investigated and it was found that, adsorption capacity of the cryogels didn't decrease significantly at the end of the 40 reuses. Catalase activity studies were also tested and it was demonstrated that desorbed catalase retained 70% of its initial activity. PMID:25746283

  1. Reactive oxygen species scavenging by catalase is important for female Lutzomyia longipalpis fecundity and mortality.

    PubMed

    Diaz-Albiter, Hector; Mitford, Roanna; Genta, Fernando A; Sant'Anna, Mauricio R V; Dillon, Rod J

    2011-01-01

    The phlebotomine sand fly Lutzomyia longipalpis is the most important vector of American visceral leishmaniasis (AVL), the disseminated and most serious form of the disease in Central and South America. In the natural environment, most female L. longipalpis are thought to survive for less than 10 days and will feed on blood only once or twice during their lifetime. Successful transmission of parasites occurs when a Leishmania-infected female sand fly feeds on a new host. Knowledge of factors affecting sand fly longevity that lead to a reduction in lifespan could result in a decrease in parasite transmission. Catalase has been found to play a major role in survival and fecundity in many insect species. It is a strong antioxidant enzyme that breaks down toxic reactive oxygen species (ROS). Ovarian catalase was found to accumulate in the developing sand fly oocyte from 12 to 48 hours after blood feeding. Catalase expression in ovaries as well as oocyte numbers was found to decrease with age. This reduction was not found in flies when fed on the antioxidant ascorbic acid in the sugar meal, a condition that increased mortality and activation of the prophenoloxidase cascade. RNA interference was used to silence catalase gene expression in female Lu. longipalpis. Depletion of catalase led to a significant increase of mortality and a reduction in the number of developing oocytes produced after blood feeding. These results demonstrate the central role that catalase and ROS play in the longevity and fecundity of phlebotomine sand flies. PMID:21408075

  2. Generation 9 polyamidoamine dendrimer encapsulated platinum nanoparticle mimics catalase size, shape, and catalytic activity.

    PubMed

    Wang, Xinyu; Zhang, Yincong; Li, Tianfu; Tian, Wende; Zhang, Qiang; Cheng, Yiyun

    2013-04-30

    Poly(amidoamine) (PAMAM) encapsulated platinum nanoparticles were synthesized and used as catalase mimics. Acetylated generation 9 (Ac-G9) PAMAM dendrimer with a molecular size around 10 nm was used as a template to synthesize platinum nanoparticles. The feeding molar ratio of Pt(4+) and Ac-G9 is 2048, and the synthesized platinum nanoparticle (Ac-G9/Pt NP) has an average size of 3.3 nm. Ac-G9/Pt NP has a similar molecular size and globular shape with catalase (~11 nm). The catalytic activity of Ac-G9/Pt NP on the decomposition of H2O2 is approaching that of catalase at 37 °C. Ac-G9/Pt NP shows differential response to the changes of pH and temperature compared with catalase, which can be explained by different catalytic mechanisms of Ac-G9/Pt NP and catalase. Ac-G9/Pt NP also shows horseradish peroxidase activity and is able to scavenge free radicals such as di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH). Furthermore, Ac-G9/Pt NP shows excellent biocompatibility on different cell lines and can down-regulate H2O2-induced intracellular reactive oxygen species (ROS) in these cells. These results suggest that dendrimers are promising mimics of proteins with different sizes and Ac-G9/Pt NP can be used as an alternative candidate of catalase to decrease oxidation stress in cells. PMID:23544351

  3. The critical role of catalase in prooxidant and antioxidant function of p53

    PubMed Central

    Kang, M Y; Kim, H-B; Piao, C; Lee, K H; Hyun, J W; Chang, I-Y; You, H J

    2013-01-01

    The tumor suppressor p53 is an important regulator of intracellular reactive oxygen species (ROS) levels, although downstream mediators of p53 remain to be elucidated. Here, we show that p53 and its downstream targets, p53-inducible ribonucleotide reductase (p53R2) and p53-inducible gene 3 (PIG3), physically and functionally interact with catalase for efficient regulation of intracellular ROS, depending on stress intensity. Under physiological conditions, the antioxidant functions of p53 are mediated by p53R2, which maintains increased catalase activity and thereby protects against endogenous ROS. After genotoxic stress, high levels of p53 and PIG3 cooperate to inhibit catalase activity, leading to a shift in the oxidant/antioxidant balance toward an oxidative status, which could augment apoptotic cell death. These results highlight the essential role of catalase in p53-mediated ROS regulation and suggest that the p53/p53R2–catalase and p53/PIG3–catalase pathways are critically involved in intracellular ROS regulation under physiological conditions and during the response to DNA damage, respectively. PMID:22918438

  4. Catalase is a sink for H2O2 and is indispensable for stress defence in C3 plants.

    PubMed Central

    Willekens, H; Chamnongpol, S; Davey, M; Schraudner, M; Langebartels, C; Van Montagu, M; Inzé, D; Van Camp, W

    1997-01-01

    Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants showed no visible disorders at low light, but in elevated light rapidly developed white necrotic lesions on the leaves. Lesion formation required photorespiratory activity since damage was prevented under elevated CO2. Accumulation of H2O2 was not detected during leaf necrosis. Alternative H2O2-scavenging mechanisms may have compensated for reduced catalase activity, as shown by increased ascorbate peroxidase and glutathione peroxidase levels. Leaf necrosis correlated with accumulation of oxidized glutathione and a 4-fold decrease in ascorbate, indicating that catalase is critical for maintaining the redox balance during oxidative stress. Such control may not be limited to peroxisomal H2O2 production. Catalase functions as a cellular sink for H2O2, as evidenced by complementation of catalase deficiency by exogenous catalase, and comparison of catalase-deficient and control leaf discs in removing external H2O2. Stress analysis revealed increased susceptibility of catalase-deficient plants to paraquat, salt and ozone, but not to chilling. PMID:9305623

  5. Primary sequence and activity analyses of a catalase from Ascaris suum.

    PubMed

    Eckelt, V H; Liebau, E; Walter, R D; Henkle-Dührsen, K

    1998-09-15

    A complete cDNA encoding the catalase (EC 1.11.1.6) has been isolated from the parasitic nematode Ascaris suum (AsCAT). The active-site residues, the residues involved in ligand interaction, and NADPH-binding residues of the bovine liver catalase-type enzyme are highly conserved in the AsCAT predicted amino acid sequence. To confirm that the AsCAT cDNA encodes a functional enzyme, active recombinant protein (rAsCAT) was produced in a procaryotic expression system. The subunit molecular mass of the purified recombinant protein (rAsCAT) was determined to be approximately 60 kDa. According to gel filtration, the molecular mass of the active enzyme is 240 kDa, indicating that the catalase subunits form a homotetramer in solution. The optical spectrum of rAsCAT shows a typical ferric haem spectrum with a Soret band at 407 nm. Fluorescence spectroscopy demonstrates that rAsCAT binds NADPH. rAsCAT has catalase activity with hydrogen peroxide over a broad pH range, with a specific activity of 37,800 U mg-1. In addition to its catalase activity, rAsCAT displays peroxidase activity using the substrates t-butyl hydroperoxide and o-dianisidine. The haem ligands NaN3 and KCN caused a 50% inhibition of catalase activity at 9 and 19 microM, respectively. In the presence of a H2O2-generating system, catalase activity of rAsCAT was inhibited by 3-aminotriazole, phenolic compounds, and drugs. PMID:9803413

  6. Reduction of Hydrogen Peroxide Accumulation and Toxicity by a Catalase from Mycoplasma iowae

    PubMed Central

    Pritchard, Rachel E.; Prassinos, Alexandre J.; Osborne, John D.; Raviv, Ziv; Balish, Mitchell F.

    2014-01-01

    Mycoplasma iowae is a well-established avian pathogen that can infect and damage many sites throughout the body. One potential mediator of cellular damage by mycoplasmas is the production of H2O2 via a glycerol catabolic pathway whose genes are widespread amongst many mycoplasma species. Previous sequencing of M. iowae serovar I strain 695 revealed the presence of not only genes for H2O2 production through glycerol catabolism but also the first documented mycoplasma gene for catalase, which degrades H2O2. To test the activity of M. iowae catalase in degrading H2O2, we studied catalase activity and H2O2 accumulation by both M. iowae serovar K strain DK-CPA, whose genome we sequenced, and strains of the H2O2-producing species Mycoplasma gallisepticum engineered to produce M. iowae catalase by transformation with the M. iowae putative catalase gene, katE. H2O2-mediated virulence by M. iowae serovar K and catalase-producing M. gallisepticum transformants were also analyzed using a Caenorhabditis elegans toxicity assay, which has never previously been used in conjunction with mycoplasmas. We found that M. iowae katE encodes an active catalase that, when expressed in M. gallisepticum, reduces both the amount of H2O2 produced and the amount of damage to C. elegans in the presence of glycerol. Therefore, the correlation between the presence of glycerol catabolism genes and the use of H2O2 as a virulence factor by mycoplasmas might not be absolute. PMID:25127127

  7. Adeno-Associated Viral-Mediated Catalase Expression Suppresses Optic Neuritis in Experimental Allergic Encephalomyelitis

    NASA Astrophysics Data System (ADS)

    Guy, John; Qi, Xiaoping; Hauswirth, William W.

    1998-11-01

    Suppression of oxidative injury by viral-mediated transfer of the human catalase gene was tested in the optic nerves of animals with experimental allergic encephalomyelitis (EAE). EAE is an inflammatory autoimmune disorder of primary central nervous system demyelination that has been frequently used as an animal model for the human disease multiple sclerosis (MS). The optic nerve is a frequent site of involvement common to both EAE and MS. Recombinant adeno-associated virus containing the human gene for catalase was injected over the right optic nerve heads of SJL/J mice that were simultaneously sensitized for EAE. After 1 month, cell-specific catalase activity, evaluated by quantitation of catalase immunogold, was increased approximately 2-fold each in endothelia, oligodendroglia, astrocytes, and axons of the optic nerve. Effects of catalase on the histologic lesions of EAE were measured by computerized analysis of the myelin sheath area (for demyelination), optic disc area (for optic nerve head swelling), extent of the cellular infiltrate, extravasated serum albumin labeled by immunogold (for blood-brain barrier disruption), and in vivo H2O2 reaction product. Relative to control, contralateral optic nerves injected with the recombinant virus without a therapeutic gene, catalase gene inoculation reduced demyelination by 38%, optic nerve head swelling by 29%, cellular infiltration by 34%, disruption of the blood-brain barrier by 64%, and in vivo levels of H2O2 by 61%. Because the efficacy of potential treatments for MS are usually initially tested in the EAE animal model, this study suggests that catalase gene delivery by using viral vectors may be a therapeutic strategy for suppression of MS.

  8. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor

    NASA Astrophysics Data System (ADS)

    Bekde?er, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Re?at

    2014-11-01

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based ‘cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 ?M). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  9. Effects of estrogen on glutathione and catalase levels in human erythrocyte during menstrual cycle

    PubMed Central

    SHENG-HUANG, CHANG; CHIEH-HSIN, CHANG; MU-CHUN, YANG; WEN-TUNG, HSU; CHIA-YING, HSIEH; YA-TING, HUNG; WAN-LING, SU; JIUAN-JEN, SHIU; CHIH-YANG, HUANG; JER-YUH, LIU

    2015-01-01

    The present study evaluated the effects of physiological serum estrogen during the menstrual cycle on glutathione (GSH) and catalase activities. The sample included 43 healthy females between the ages of 22 and 51 years. The subjects were divided into two groups according to the stage of the menstrual cycle. Group A consisted of 16 samples extracted between days 10 and 20 from the first day of menstruation when estrogen levels were considered to be at their highest. Group B consisted of 27 samples extracted during other times of the estimated 30 days of menstruation. Data showed that the estrogen level in group A (184±106 pg/ml) was higher than that in group B (105±56 pg/ml) (P<0.01). The GSH and catalase levels in group A (4.4±2.3 µg/mg and 210±72 IU/mg, respectively) were also significantly higher compared to the levels in group B (3.2±1.8 µg/mg and 168±62 IU/mg, respectively) (P <0.05). Spearman's rank correlation showed that the expression of catalase in red blood cells significantly correlated with serum estrogen level but not with GSH. However, the changes in estrogen plasma levels, erythrocyte GSH level and catalase activity suggested that the consumption of GSH and catalase in erythrocyte during the menstrual cycle may be associated with the level of estrogen present in the bloodstream. PMID:25798250

  10. UV-resistant Acinetobacter sp. isolates from Andean wetlands display high catalase activity.

    PubMed

    Di Capua, Cecilia; Bortolotti, Ana; Farías, María Eugenia; Cortez, Néstor

    2011-04-01

    Andean wetlands are characterized by their extreme environmental conditions such as high UV radiation, elevated heavy metal content and salinity. We present here the first study on UV tolerance and antioxidant defense of four Acinetobacter strains: Ver3, Ver5 and Ver7, isolated from Lake Verde, and N40 from Lake Negra, both lakes located 4400 m above sea level. All four isolates displayed higher UV resistance compared with collection strains, with Ver3 and Ver7 being the most tolerant strains not only to UV radiation but also to hydrogen peroxide (H(2)O(2)) and methyl viologen (MV) challenges. A single superoxide dismutase band with similar activity was detected in all studied strains, whereas different electrophoretic pattern and activity levels were observed for catalase. Ver3 and Ver7 displayed 5-15 times higher catalase activity levels than the control strains. Analysis of the response of antioxidant enzymes to UV and oxidative challenges revealed a significant increase in Ver7 catalase activity after H(2)O(2) and MV exposure. Incubation of Ver7 cultures with a catalase inhibitor resulted in a significant decrease of tolerance against UV radiation. We conclude that the high catalase activity displayed by Ver7 isolate could play an important role in UV tolerance. PMID:21276048

  11. Purification and characterization of catalase from sprouted black gram (Vigna mungo) seeds.

    PubMed

    Kandukuri, Sai Srikar; Noor, Ayesha; Ranjini, S Shiva; Vijayalakshmi, M A

    2012-03-15

    Black gram (Vigna mungo) is a legume which belongs to Fabaceae family. It is a rich source of protein. It has been known to have interesting small molecule antioxidant activity. However, its enzymatic antioxidant properties have not been explored much. In the present work we studied catalase, a principal antioxidant enzyme from black gram seeds. Day four sprouted black gram seeds were found to have a significant catalase content approximately of 15,240 U/g seeds. IMAC (Seph 4B-IDA-Zn(II)) was used for purifying this catalase, a purification fold of 106 and a high specific activity of 25,704 U/mg was obtained. The K(m) and V(max) of the purified catalase were found to be 16.2 mM and 2.5 ?mol/min. The effect of inhibitors like Sodium azide (NaN(3)) and EDTA and different metal ions on catalase activity were studied. NaN(3), Fe(3+)and Cu(2+) were found to have profound inhibitory effects on the enzyme activity. Other metal ions like Ni(2+), Ca(2+), Mg(2+) and Mn(2+) had both enhancing and inhibitory effects. The enzyme showed optimal activity at a temperature of 40°C and pH 7.0. It was stable over a broad range of pH 6.0-10.0 and had a half life of 7h 30 min at 50°C. PMID:22341355

  12. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    PubMed

    Bekde?er, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Re?at

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 ?M). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC. PMID:24887508

  13. Catalase: a tetrameric enzyme with four tightly bound molecules of NADPH.

    PubMed Central

    Kirkman, H N; Gaetani, G F

    1984-01-01

    Catalases (H2O2:H2O2 oxidoreductase, EC 1.11.1.6) from many species are known to be tetramers of 60,000-dalton subunits, with four heme groups per tetramer. Previous authors have determined the amino acid sequence and three-dimensional structure of bovine liver catalase. Studies of the regulation of the pentose phosphate pathway led the present authors to a search for proteins that bind NADP+ and NADPH in human erythrocytes. An unexpected result of that search was the finding that a major reservoir of bound NADPH in human erythrocytes is catalase. Each tetrameric molecule of human or bovine catalase contains four molecules of tightly bound NADPH. The binding sites have the relative affinities NADPH greater than NADH greater than NADP+ greater than NAD+. NADPH does not seem to be essential for the enzymic conversion of H2O2 to O2 and water but does provide protection of catalase against inactivation by H2O2. PMID:6589599

  14. Sequential inactivation of reactive oxygen species by combined overexpression of SOD isoforms and catalase in insulin-producing cells

    Microsoft Academic Search

    Stephan Lortz; Markus Tiedge

    2003-01-01

    Insulin-producing cells show very low activity levels of the cytoprotective enzymes catalase, glutathione peroxidase, and superoxide dismutase. This weak antioxidative defense status has been considered a major feature of the poor resistance against oxidative stress. Therefore, we analyzed the protective effect of a combined overexpression of Cu,ZnSOD or MnSOD together with different levels of catalase. Catalase alone was able to

  15. Expression of a bacterial catalase in a strictly anaerobic methanogen significantly increases tolerance to hydrogen peroxide but not oxygen

    PubMed Central

    Jennings, Matthew E.; Schaff, Cody W.; Horne, Alexandra J.; Lessner, Faith H.

    2014-01-01

    Haem-dependent catalase is an antioxidant enzyme that degrades H2O2, producing H2O and O2, and is common in aerobes. Catalase is present in some strictly anaerobic methane-producing archaea (methanogens), but the importance of catalase to the antioxidant system of methanogens is poorly understood. We report here that a survey of the sequenced genomes of methanogens revealed that the majority of species lack genes encoding catalase. Moreover, Methanosarcina acetivorans is a methanogen capable of synthesizing haem and encodes haem-dependent catalase in its genome; yet, Methanosarcina acetivorans cells lack detectable catalase activity. However, inducible expression of the haem-dependent catalase from Escherichia coli (EcKatG) in the chromosome of Methanosarcina acetivorans resulted in a 100-fold increase in the endogenous catalase activity compared with uninduced cells. The increased catalase activity conferred a 10-fold increase in the resistance of EcKatG-induced cells to H2O2 compared with uninduced cells. The EcKatG-induced cells were also able to grow when exposed to levels of H2O2 that inhibited or killed uninduced cells. However, despite the significant increase in catalase activity, growth studies revealed that EcKatG-induced cells did not exhibit increased tolerance to O2 compared with uninduced cells. These results support the lack of catalase in the majority of methanogens, since methanogens are more likely to encounter O2 rather than high concentrations of H2O2 in the natural environment. Catalase appears to be a minor component of the antioxidant system in methanogens, even those that are aerotolerant, including Methanosarcina acetivorans. Importantly, the experimental approach used here demonstrated the feasibility of engineering beneficial traits, such as H2O2 tolerance, in methanogens. PMID:24222618

  16. Bioactive Compounds in the Flora of Belarus. 2. Astragalin, an Effective Protector of Catalase from Ultrasonic Inactivation in Aqueous Solutions

    Microsoft Academic Search

    N. V. Kovganko; Zh. N. Kashkan; S. N. Krivenok; M. V. Potapovich; A. N. Eremin; D. I. Metelitsa

    2004-01-01

    The kinetics of catalase decomposition of H2O2 (50 mM) inhibited by the flavonolic glycoside astragalin (1) from the aerial part of Gymnocarpium dryopteris were studied. 1 (0.3-30 M) is a strong inhibitor of the catalase process and was tested as a catalase (CAT) protector from ultrasonic activation at 45°C by treatment of enzyme solutions (1.2 nM) in phosphate buffer (7.5

  17. Targeted intracellular catalase delivery protects neonatal rat myocytes from hypoxia-reoxygenation and ischemia-reperfusion injury

    PubMed Central

    Undyala, Vishnu; Terlecky, Stanley R.; Vander Heide, Richard S.

    2010-01-01

    Hypoxia followed by reoxygenation (HR) and ischemia-reperfusion (IR) cause cell death in neonatal rat ventricular myocytes (NRVM) primarily through the generation of oxidative stress. Extracellular catalase (CAT) has not been effective in reducing or eliminating IR or HR-induced cell death due both to extracellular degradation and poor cellular uptake. Aims 1) to determine if a cell penetrating catalase derivative with enhanced peroxisome targeting efficiency (catalase-SKL) increases intracellular levels of the antioxidant enzyme in NVRM; and 2) to determine if catalase-SKL protects against both HR and IR injury. Methods NRVM were subjected to 3 or 6 hr of HR or 1 hr of IR. CAT concentration, activity, and subcellular distribution were determined using standard techniques. Reactive oxygen species (ROS) and related oxidative stress were visualized using 2’,7’-dichlorofluorescin diacetate. Cell death was measured using trypan blue exclusion or lactate dehydrogenase (LDH) release assays. Results CAT activity was higher in (catalase-SKL) transduced myocytes, was concentrated in a membranous cellular fraction, and potently inhibited oxidative stress. In contrast to non-transducible (unmodified) CAT, catalase-SKL-treated myocytes were protected against both HR and IR. Conclusions 1) catalase-SKL increased myocyte CAT content and activity and dramatically increased resistance to hydrogen peroxide-induced oxidation; 2) catalase-SKL protects against both HR and IR; 3) catalase-SKL may represent a new therapeutic approach to protect hearts against myocardial HR or IR. PMID:20708413

  18. Synergistic effects between catalase inhibitors and modulators of nitric oxide metabolism on tumor cell apoptosis.

    PubMed

    Scheit, Katrin; Bauer, Georg

    2014-10-01

    Inhibitors of catalase (such as ascorbate, methyldopa, salicylic acid and neutralizing antibodies) synergize with modulators of nitric oxide (NO) metabolism (such as arginine, arginase inhibitor, NO synthase-inducing interferons and NO dioxygenase inhibitors) in the singlet oxygen-mediated inactivation of tumor cell protective catalase. This is followed by reactive oxygen species (ROS)-dependent apoptosis induction. TGF-beta, NADPH oxidase-1, NO synthase, dual oxidase-1 and caspase-9 are characterized as essential catalysts in this process. The FAS receptor and caspase-8 are required for amplification of ROS signaling triggered by individual compounds, but are dispensable when the synergistic effect is established. Our findings explain the antitumor effects of catalase inhibitors and of compounds that target NO metabolism, as well as their synergy. These data may have an impact on epidemiological studies related to secondary plant compounds and open new perspectives for the establishment of novel antitumor drugs and for the improvement of established chemotherapeutics. PMID:25275027

  19. Enzymatic exploration of catalase from a nanoparticle producing and biodecolorizing algae Shewanella xiamenensis BC01.

    PubMed

    Ng, I-Son; Xu, Fangxin; Zhang, Xia; Ye, Chiming

    2015-05-01

    Shewanella xiamenensis (SXM) was found to produce nanoparticles (NPs) under aerobic condition. The oxidoreductase enzymatic activities including of catalase, manganese peroxidase, laccase, NADH dehydrogenase, flavin reductase, azoreductase and Fe reductase are first investigated. Catalase showed the greatest enzymatic activity among all oxidoreductases in SXM, which with strong activities in multiple substrates of ABTS, guaiacol and 2,6-DMP. The optimum temperature, pH, concentrations of H2O2 and 2,6-DMP for this enzyme were found to be 65°C, pH 4.0, 128.7mM and 10mM, respectively. Finally, from the kinetic parameters and structure simulation of catalase, implied that SXM would potentially apply in bioremediation, microbe fuel cells (MFCs) and nano-biotechnology based on its distinguished enzymatic system. PMID:25306444

  20. Subchronic exposure to high-dose ACE-inhibitor moexipril induces catalase activity in rat liver.

    PubMed

    Adeghate, E; Hasan, M Y; Ponery, A S; Nurulain, S M; Petroianu, G A

    2005-12-01

    The long-term clinical effects of ACE-inhibitors have similarities with those of both fibrates and glitazones, activators of peroxisome proliferator activator receptor (PPAR) alpha and gamma, respectively. The antioxidant enzyme catalase, a heme protein that degrades hydrogen peroxide, is found at high concentrations in peroxisomes. Catalase activity is one of the recognized surrogate markers indicative of PPAR activation in the rat liver. The purpose of the study was to establish the effect of moexipril on catalase activity and to compare it with the effect of both saline controls and that of the known PPAR agonist clofibrate (positive control). Three groups of seven rats were used. All substances were applied i.p. daily for 5 days, followed by a 2-day break. The cycle was repeated eight times. After the final cycle (day 56) the animals were sacrificed and liver tissue collected. The number of catalase positive cells in both moexipril group (95% CI 57-61) and clofibrate group (95% CI 72-80) is higher than in controls (95% CI 3-16) (p < or = 0.01). The number of catalase positive cells in the clofibrate group is higher than in the moexipril group (p < or = 0.01). High-dose subchronic exposure to the ACE-inhibitor moexipril induces catalase activity in the rat liver to an extent comparable to fibrates. We suggest that some of the long-term advantages of ACE inhibitor use - beyond mere BP lowering - might be due to a PPAR mediated effect. PMID:16311918

  1. Ferryl intermediates of catalase captured by time-resolved Weissenberg crystallography and UV-VIS spectroscopy.

    PubMed

    Gouet, P; Jouve, H M; Williams, P A; Andersson, I; Andreoletti, P; Nussaume, L; Hajdu, J

    1996-11-01

    Various enzymes use semi-stable ferryl intermediates and free radicals during their catalytic cycle, amongst them haem catalases. Structures for two transient intermediates (compounds I and II) of the NADPH-dependent catalase from Proteus mirabilis (PMC) have been determined by time-resolved X-ray crystallography and single crystal microspectrophotometry. The results show the formation and transformation of the ferryl group in the haem, and the unexpected binding of an anion during this reaction at a site distant from the haem. PMID:8901874

  2. Genetic regulation of the expression of catalase activity in murine red blood cells

    Microsoft Academic Search

    C. K. Grieshaber; H. A. Hoffman

    1975-01-01

    The specific activity (k'1) and concentration of red blood cell catalase from four inbred strains of mice (BALB\\/c, C57BL, C57BL\\/6, and NBL) were measured to determine the mechanisms responsible for interstrain variations in enzyme activity. The specific activities of RBC catalase in NBL and the C57BL sublines are equal (2.5×107m-1 sec-1), while that of BALB\\/c (4.0×107m-1 sec-1) is 67% greater.

  3. Genotype???activity relationship for Mn-superoxide dismutase, glutathione peroxidase 1 and catalase in humans

    Microsoft Academic Search

    Maria Bastaki; Karen Huen; Paolo Manzanillo; Neha Chande; Connie Chen; John R. Balmes; Ira B. Tager; Nina Holland

    2006-01-01

    Results Minor allele frequencies ranged from 13% for catalase (T) to 18% for GPX1 (T), and 33% for MnSOD(C) with significant variation between ethnicities. Median GPX1 activity was 13.2U\\/g Hb with a six-fold difference between lowest and highest levels. Catalase activity ranged eight-fold (median: 86.3k\\/g Hb), while median MnSOD activity was 2.8U\\/mg Hb with a 56-fold range of values. MnSOD

  4. Purification, crystallization and preliminary crystallographic analysis of KatB, a manganese catalase from Anabaena PCC 7120.

    PubMed

    Bihani, Subhash Chandra; Chakravarty, Dhiman; Ballal, Anand

    2013-11-01

    Catalases are enzymes that play an important role in the detoxification of hydrogen peroxide (H2O2) in aerobic organisms. Among catalases, haem-containing catalases are ubiquitously distributed and their enzymatic mechanism is very well understood. On the other hand, manganese catalases that contain a bimanganese core in the active site have been less well characterized and their mode of action is not fully understood. The genome of Anabaena PCC 7120 does not show the presence of a haem catalase-like gene; instead, two ORFs encoding manganese catalases (Mn-catalases) are present. Here, the crystallization and preliminary X-ray crystallographic analysis of KatB, one of the two Mn-catalases from Anabaena, are reported. KatB was crystallized using the hanging-drop vapour-diffusion method with PEG 400 as a precipitant and calcium acetate as an additive. Diffraction data were collected in-house on an Agilent SuperNova system using a microfocus sealed-tube X-ray source. The crystal diffracted to 2.2?Å resolution at 100?K. The tetragonal crystal belonged to space group P4(1)2(1)2 (or enantiomer), with unit-cell parameters a = b = 101.87, c = 138.86?Å. Preliminary X-ray diffraction analysis using the Matthews coefficient and self-rotation function suggests the presence of a trimer in the asymmetric unit. PMID:24192374

  5. Mitochondrial targeting of a catalase transgene product by plasmid liposomes increases radioresistance in vitro and in vivo.

    PubMed

    Epperly, Michael W; Melendez, J A; Zhang, Xichen; Nie, Suhua; Pearce, Linda; Peterson, James; Franicola, Darcy; Dixon, Tracy; Greenberger, Benjamin A; Komanduri, Paavani; Wang, Hong; Greenberger, Joel S

    2009-05-01

    To determine whether increased mitochondrially localized catalase was radioprotective, a human catalase transgene was cloned into a small pSVZeo plasmid and localized to the mitochondria of 32D cl 3 cells by adding the mitochondrial localization sequence of MnSOD (mt-catalase). The cell lines 32D-Cat and 32D-mt-Cat had increased catalase biochemical activity as confirmed by Western blot analysis compared to the 32D cl 3 parent cells. The MnSOD-overexpressing 32D cl 3 cell line, 2C6, had decreased baseline catalase activity that was increased in 2C6-Cat and 2C6-mt-Cat subclonal cell lines. 32D-mt-Cat cells were more radioresistant than 32D-Cat cells, but both were radioresistant relative to 32D cl 3 cells. 2C6-mt-Cat cells but not 2C6-Cat cells were radioresistant compared to 2C6 cells. Intratracheal injection of the mt-catalase-plasmid liposome complex (mt-Cat-PL) but not the catalase-plasmid liposome complex (Cat-PL) increased the resistance of C57BL/6NHsd female mice to 20 Gy thoracic irradiation compared to MnSOD-plasmid liposomes. Thus mitochondrially targeted overexpression of the catalase transgene is radioprotective in vitro and in vivo. PMID:19580494

  6. Mitochondrial Targeting of a Catalase Transgene Product by Plasmid Liposomes Increases Radioresistance In Vitro and In Vivo

    PubMed Central

    Epperly, Michael W.; Melendez, J. A.; Zhang, Xichen; Nie, Suhua; Pearce, Linda; Peterson, James; Franicola, Darcy; Dixon, Tracy; Greenberger, Benjamin A.; Komanduri, Paavani; Wang, Hong; Greenberger, Joel S.

    2009-01-01

    To determine whether increased mitochondrially localized catalase was radioprotective, a human catalase transgene was cloned into a small pSVZeo plasmid and localized to the mitochondria of 32D cl 3 cells by adding the mitochondrial localization sequence of MnSOD (mt-catalase). The cell lines 32D-Cat and 32D-mt-Cat had increased catalase biochemical activity as confirmed by Western blot analysis compared to the 32D cl 3 parent cells. The MnSOD-overexpressing 32D cl 3 cell line, 2C6, had decreased baseline catalase activity that was increased in 2C6-Cat and 2C6-mt-Cat subclonal cell lines. 32D-mt-Cat cells were more radioresistant than 32D-Cat cells, but both were radioresistant relative to 32D cl 3 cells. 2C6-mt-Cat cells but not 2C6-Cat cells were radioresistant compared to 2C6 cells. Intratracheal injection of the mt-catalase-plasmid liposome complex (mt-Cat-PL) but not the catalase-plasmid liposome complex (Cat-PL) increased the resistance of C57BL/6NHsd female mice to 20 Gy thoracic irradiation compared to MnSOD-plasmid liposomes. Thus mitochondrially targeted overexpression of the catalase transgene is radioprotective in vitro and in vivo. PMID:19580494

  7. Catalase and glutathione peroxidase are equally active in detoxification of hydrogen peroxide in human erythrocytes.

    PubMed

    Gaetani, G F; Galiano, S; Canepa, L; Ferraris, A M; Kirkman, H N

    1989-01-01

    Genetic deficiencies of glucose-6-phosphate dehydrogenase (G6PD) and NADPH predispose affected erythrocytes to destruction from peroxides. Conversely, genetic deficiencies of catalase do not predispose affected erythrocytes to peroxide-induced destruction. These observations have served to strengthen the assumption that the NADPH/glutathione/glutathione peroxidase pathway is the principal means for disposal of H2O2 in human erythrocytes. Recently, however, mammalian catalase was found to have tightly bound NADPH and to require NADPH for the prevention and reversal of inactivation by its toxic substrate (H2O2). Since both catalase and the glutathione pathway are dependent on NADPH for function, this finding raises the possibility that both mechanisms destroy H2O2 in human erythrocytes. A comparison of normal and acatalasemic erythrocytes in the present study indicated that catalase accounts for more than half of the destruction of H2O2 when H2O2 is generated at a rate comparable to that which leads to hemolysis in G6PD- deficient erythrocytes. PMID:2491951

  8. Rapid One-Step Isolation of Mouse Liver Catalase by Immobilized Metal Ion Affinity Chromatography

    Microsoft Academic Search

    Qian Yang; Joseph W. DePierre

    1998-01-01

    A novel and rapid procedure for the isolation of catalase from mouse liver, after prior treatment with the peroxisome proliferator perfluorooctanoic acid was developed using immobilized metal ion affinity chromatography involving chelation with zinc ions. The purification developed is simple, rapid (requiring 3 hours from cytosol or peroxisomal matrix to homogeneous proteins), reproducible, and yields virtually complete overall recovery of

  9. Low Catalase Activity in Rats with Ureteral Ligation: Relation to Lipid Peroxidation

    Microsoft Academic Search

    1998-01-01

    Progression of some renal diseases is characterized by generation of reactive oxygen metabolites that are also involved in the pathophysiology of obstructive nephropathy. Catalase activity and lipid peroxidation were investigated in rats with unilaterally (UUL) and bilaterally ligated ureters (BUL). Forty-eight hours after ligation, the animals were sacrificed, and enzyme activity as well as the malondialdehyde (MDA) concentration were measured

  10. Effect of antibiotics of the tetracycline group on the activity of liver catalase

    Microsoft Academic Search

    R. P. Porfir'eva

    1962-01-01

    Tetracyclines were given to rats per os in a dose of 100 mg\\/kg for a period of 5 days. Chlortetracycline and tetracycline caused a reduction of hepatic catalase activity. Oxytetracycline had practically no effect on this enzyme. In experiments with the addition of antibiotics into the reagents' mixture in concentrations of 5, 50 and 200 µg\\/ml all the 3 tetracyclines

  11. Catalase activity measured with a micro oxygen electrode in a pressurized reaction vessel. [Mice, rats

    Microsoft Academic Search

    Halbach

    1977-01-01

    The assembly and the use of a simple airtight pressurized reaction vessel are described for the measurement of catalase activity with a micro oxygen electrode in an optically heterogenous medium. The oxygen concentration is expressed as the ratio of observed current to the current in an air-saturated solution. Thus, an individual standard can be obtained for each measurement and the

  12. Hydrogen peroxide homeostasis: activation of plant catalase by calcium/calmodulin

    NASA Technical Reports Server (NTRS)

    Yang, T.; Poovaiah, B. W.

    2002-01-01

    Environmental stimuli such as UV, pathogen attack, and gravity can induce rapid changes in hydrogen peroxide (H(2)O(2)) levels, leading to a variety of physiological responses in plants. Catalase, which is involved in the degradation of H(2)O(2) into water and oxygen, is the major H(2)O(2)-scavenging enzyme in all aerobic organisms. A close interaction exists between intracellular H(2)O(2) and cytosolic calcium in response to biotic and abiotic stresses. Studies indicate that an increase in cytosolic calcium boosts the generation of H(2)O(2). Here we report that calmodulin (CaM), a ubiquitous calcium-binding protein, binds to and activates some plant catalases in the presence of calcium, but calcium/CaM does not have any effect on bacterial, fungal, bovine, or human catalase. These results document that calcium/CaM can down-regulate H(2)O(2) levels in plants by stimulating the catalytic activity of plant catalase. Furthermore, these results provide evidence indicating that calcium has dual functions in regulating H(2)O(2) homeostasis, which in turn influences redox signaling in response to environmental signals in plants.

  13. Distribution of superoxide dismutase, catalase, and peroxidase activities among Treponema pallidum and other spirochetes.

    PubMed

    Austin, F E; Barbieri, J T; Corin, R E; Grigas, K E; Cox, C D

    1981-08-01

    Representative members of Spirochaetales were surveyed for their content of superoxide dismutase (SOD), catalase, and peroxidase activities. Only Leptospira exhibited peroxidase activity. Obligately anaerobic cultivable Treponema and Spirochaeta possessed no SOD or peroxidative capabilities. Upon polyacrylamide gel electrophoresis, Spirochaeta aurantia, Borrelia hermsi, and five Leptospira biflexa serovars showed SOD activity associated with one electrophoretic band which was inhibited by H2O2, suggesting that they were iron-containing dismutases. These spirochetes could be distinguished by differences in relative mobilities of their SODs. SOD activity, but not catalase activity, was induced aerobically in S. aurantia. All Leptospira interrogans serovars and two L. biflexa serovars lacked significant SOD activity. These SOD-deficient strains of Leptospira, with one exception, possessed high levels of catalase activity. The Nichols strain of virulent Treponema pallidum possessed SOD and catalase activities, but lacked peroxidase activity. The SOD in T. pallidum exhibited two electrophoretic bands containing copper and zinc, and its relative mobility was identical to that of purified rabbit SOD. Immunization of sheep with purified rabbit SOD resulted in antiserum which inhibited both rabbit SOD and T. pallidum SOD assayed by spectrophotometric analysis or activity staining following polyacrylamide gel electrophoresis. In agarose gel diffusion, precipitin lines of identity were observed between purified rabbit SOD and cell extracts of T. pallidum. These data indicated that the SOD activity detected in T. pallidum was host derived. PMID:7024127

  14. Do Superoxide Dismutase (SOD) and Catalase (CAT) protect Cells from DNA Damage Induced by Active Arsenicals?

    EPA Science Inventory

    Superoxide dismutase (SOD) catalyzes the conversion of superoxide to hydrogen peroxide, which can be converted to water and oxygen through the action of catalase. Heterozygous mice of strain B6: 129S7-SodltmlLeb/J were obtained from Jackson Laboratories and bred to produce offspr...

  15. Catalase activity and expression in developing sunflower seeds as related to drying

    Microsoft Academic Search

    Christophe Bailly; Juliette Leymarie; Arnaud Lehner; Sandra Rousseau; Francoise Corbineau

    2004-01-01

    Changes in catalase (CAT) activity and in CAT iso- form pattern and expression were investigated in developing sunflower (Helianthus annuus L.) seeds during desiccation on the mother plant and after arti- ficial drying on the flowerheads. Seeds regularly des- iccated during their development on the mother plant and reached mass maturity at c. 42 d after flowering (DAF). Freshly harvested

  16. A study of the inhibition of catalase by dipotassium trioxohydroxytetrafluorotriborate K?[B?O?F?OH].

    PubMed

    Islamovic, Safija; Galic, Borivoj; Milos, Mladen

    2014-10-01

    In the development of boronic acid-based enzyme inhibitors as potential pharmaceutical drugs, dipotassium trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was listed as a promising new therapeutic for treatment of these diseases. The catalase-mediated conversion of hydrogen peroxide, in the presence and absence of K2[B3O3F4OH] was studied. The kinetics conformed to the Michaelis-Menten model. Lineweaver-Burk plots were linear and plotted the family of straight lines intersected on the abscissa indicating non-competitive inhibition of the catalase. It appears that in the absence of inhibitor, catalase operates the best at conditions around pH 7.1 and in the presence of K2[B3O3F4OH] the optimum is around pH 6.2. The uncatalyzed reaction of hydrogen peroxide decomposition generally has a value of activation energy of 75?kJ?mole(-1), whereas catalase, in the absence of inhibitor, lowers the value to 11.2?kJ?mole(-1), while in the presence 69?mmoles?L(-1) of K2[B3O3F4OH] it was 37.8?kJ?mole(-1). PMID:24506205

  17. Impedance spectroscopy and conductometric biosensing for probing catalase reaction with cyanide as ligand and inhibitor.

    PubMed

    Bouyahia, Naima; Hamlaoui, Mohamed Larbi; Hnaien, Mouna; Lagarde, Florence; Jaffrezic-Renault, Nicole

    2011-02-01

    In this work, a new biosensor was prepared through immobilization of bovine liver catalase in a photoreticulated poly (vinyl alcohol) membrane at the surface of a conductometric transducer. This biosensor was used to study the kinetics of catalase-H(2)0(2) reaction and its inhibition by cyanide. Immobilized catalase exhibited a Michaelis-Menten behaviour at low H(2)0(2) concentrations (<100mM) with apparent constant K(M)(app)=84±3mM and maximal initial velocity V(M)(app)=13.4?S min(-1). Inhibition by cyanide was found to be non-competitive and inhibition binding constant K(i) was 13.9±0.3?M. The decrease of the biosensor response by increasing cyanide concentration was linear up to 50?M, with a cyanide detection limit of 6?M. In parallel, electrochemical characteristics of the catalase/PVA biomembrane and its interaction with cyanide were studied by cyclic voltammetry and impedance spectroscopy. Addition of the biomembrane onto the gold electrodes induced a significant increase of the interfacial polarization resistance R(P). On the contrary, cyanide binding resulted in a decrease of Rp proportional to KCN concentration in the 4 to 50?M range. Inhibition coefficient I(50) calculated by this powerful label-free and substrate-free technique (24.3?M) was in good agreement with that determined from the substrate-dependent conductometric biosensor (24.9?M). PMID:20813591

  18. Associations between Breast Cancer Risk and the Catalase Genotype, Fruit and Vegetable Consumption, and Supplement Use

    Microsoft Academic Search

    Jiyoung Ahn; Marilie D. Gammon; Regina M. Santella; Mia M. Gaudet; Julie A. Britton; Susan L. Teitelbaum; Mary Beth Terry; Susan Nowell; Warren Davis; Cutberto Garza; Alfred I. Neugut; Christine B. Ambrosone

    2005-01-01

    Observed weak or null associations between fruit and vegetable intake and breast cancer risk could be due to heterogeneity in endogenous antioxidant capabilities. The authors evaluated potential relations between a func- tional polymorphism in catalase, an antioxidant enzyme, and breast cancer risk, particularly in relation to fruit and vegetable intake and supplement use. Women (1,008 cases and 1,056 controls) in

  19. Role of catalase in the virulence of Brucella melitensis in pregnant goats

    Microsoft Academic Search

    Jason M. Gee; Michael E. Kovach; Vanessa K. Grippe; Sue Hagius; Joel V. Walker; Philip H. Elzer; R. Martin Roop

    2004-01-01

    An isogenic katE mutant derived from virulent Brucella melitensis 16M displays hypersensitivity to hydrogen peroxide in disk sensitivity assays but retains the capacity to colonize pregnant goats and induce abortion. These experimental findings indicate that although the sole periplasmic catalase of Brucella melitensis functions as an antioxidant, this enzyme does not play a critical role in virulence in the natural

  20. The effect of superoxide dismutase mimetic and catalase on the quality of postthawed goat semen.

    PubMed

    Shafiei, Mojtaba; Forouzanfar, Mohsen; Hosseini, Sayyed Morteza; Nasr Esfahani, Mohammad Hossein

    2015-05-01

    Manganese(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin chloride (MnTE) is a cell-permeable superoxide dismutase mimetic agent which can convert superoxide to hydrogen peroxide (H2O2). Supplementation of MnTE to a commercial semen extender can protect sperm from superoxide but not H2O2. Therefore, we proposed that addition of catalase (0.0, 200, or 400 IU/mL) in combination with MnTE (0.1 ?M) may further improve the cryopreservation efficiency of goat semen in commercially optimized freezing media such as Andromed. Therefore, ejaculates were obtained from three adult bucks twice a week during the breeding season and diluted with Andromed supplemented with or without MnTE and catalase and were frozen in liquid nitrogen. Sperm parameters and reactive oxygen species contents were evaluated 2 hours after dilution (before freezing) and after freezing/thawing. The results revealed that all the treatments significantly (P ? 0.05) improved sperm motility, viability, and membrane integrity after freezing and reduced reactive oxygen species content compared with the control group, but maximum improvement was obtained in MnTE + 400 IU/mL catalase. In addition, supplementation with these antioxidants significantly (P ? 0.05) increases the cleavage rate after IVF. In conclusion, the results of present study suggest that addition of antioxidant MnTE or catalase to commercial optimized media, such as Andromed, improves total motility, membrane integrity, and viability of goat semen samples after thawing. But the degree of improvement for these parameters significantly (P ? 0.05) higher when MnTE and catalase were simultaneously added to the cryopreservation media. PMID:25698161

  1. Improved human sperm recovery using superoxide dismutase and catalase supplementation in semen cryopreservation procedure.

    PubMed

    Rossi, T; Mazzilli, F; Delfino, M; Dondero, F

    2001-01-01

    The aim of this work was to evaluate the effects of ROS scavenger supplementation in human semen samples undergoing cryopreservation procedures.After screening out andrological pathologies, we selected 25 male partners of infertile couples with the following semen profile: volume >/= 2.0 ml, normal viscosity, sperm count >/=20 x 10(6)/ml, straight progressive motility (classes 1 and 2) >/= 40% (Mazzilli, Rossi, Delfino and Nofroni (1999) Andrologia 31: 187-194), atypical forms catalase to the third and both SOD (100 U/ml) and catalase (100 U/ml) were added to the fourth aliquot. Each aliquot was mixed (v/v) with TEST yolk buffer freezing medium (Irvine Scientific) and then frozen at -196 degrees C. The percent recovery of progressive motile and swollen spermatozoa was evaluated after thawing.No significant variation in the recovery of progressive motility was seen in the aliquots with added SOD or catalase alone, compared to the control group. On the other hand, a significant improvement in sperm parameter recovery was seen in the aliquot with both SOD and catalase supplementation; perhaps because of their combined and simultaneous action on superoxide anion and hydrogen peroxide. These results suggest that, in some selected cases, SOD and catalase supplementation can contribute greatly to the prevention of sperm membrane lipid peroxidation by ROS and thus allow good sperm parameter recovery after freezing-thawing procedures. PMID:15256925

  2. LESION SIMULATING DISEASE1 Interacts with Catalases to Regulate Hypersensitive Cell Death in Arabidopsis1[C][W

    PubMed Central

    Li, Yansha; Chen, Lichao; Mu, Jinye; Zuo, Jianru

    2013-01-01

    LESION SIMULATING DISEASE1 (lsd1) is an important negative regulator of programmed cell death (PCD) in Arabidopsis (Arabidopsis thaliana). The loss-of-function mutations in lsd1 cause runaway cell death triggered by reactive oxygen species. lsd1 encodes a novel zinc finger protein with unknown biochemical activities. Here, we report the identification of CATALASE3 (CAT3) as an lsd1-interacting protein by affinity purification and mass spectrometry-based proteomic analysis. The Arabidopsis genome contains three homologous catalase genes (CAT1, CAT2, and CAT3). Yeast two-hybrid and coimmunoprecipitation analyses demonstrated that lsd1 interacted with all three catalases both in vitro and in vivo, and the interaction required the zinc fingers of lsd1. We found that the catalase enzymatic activity was reduced in the lsd1 mutant, indicating that the catalase enzyme activity was partially dependent on lsd1. Consistently, the lsd1 mutant was more sensitive to the catalase inhibitor 3-amino-1,2,4-triazole than the wild type, suggesting that the interaction between lsd1 and catalases is involved in the regulation of the reactive oxygen species generated in the peroxisome. Genetic studies revealed that lsd1 interacted with CATALASE genes to regulate light-dependent runaway cell death and hypersensitive-type cell death. Moreover, the accumulation of salicylic acid was required for PCD regulated by the interaction between lsd1 and catalases. These results suggest that the lsd1-catalase interaction plays an important role in regulating PCD in Arabidopsis. PMID:23958864

  3. Benzothiazole Aniline Tetra(ethylene glycol) and 3-Amino-1,2,4-triazole Inhibit Neuroprotection against Amyloid Peptides by Catalase Overexpression in Vitro

    PubMed Central

    2013-01-01

    Alzheimer’s disease, Familial British dementia, Familial Danish dementia, Type 2 diabetes mellitus, plus Creutzfeldt-Jakob disease are associated with amyloid fibril deposition and oxidative stress. The antioxidant enzyme catalase is a neuroprotective amyloid binding protein. Herein the effects of catalase overexpression in SH-SY5Y neuronal cells on the toxicity of amyloid-? (A?), amyloid-Bri (ABri), amyloid-Dan (ADan), amylin (IAPP), and prion protein (PrP) peptides were determined. Results showed catalase overexpression was neuroprotective against A?, ABri, ADan, IAPP, and PrP peptides. The catalase inhibitor 3-amino-1,2,4-triazole (3-AT) and catalase-amyloid interaction inhibitor benzothiazole aniline tetra(ethylene glycol) (BTA-EG4) significantly enhanced neurotoxicity of amyloid peptides in catalase overexpressing neuronal cells. This suggests catalase neuroprotection involves breakdown of hydrogen peroxide (H2O2) plus a direct binding interaction between catalase and the A?, ABri, ADan, IAPP, and PrP peptides. Kisspeptin 45–50 had additive neuroprotective actions against the A? peptide in catalase overexpressing cells. The effects of 3-AT had an intracellular site of action, while catalase-amyloid interactions had an extracellular component. These results suggest that the 3-AT and BTA-EG4 compounds may be able to inhibit endogenous catalase mediated neuroprotection. Use of BTA-EG4, or compounds that inhibit catalase binding to amyloid peptides, as potential therapeutics for Neurodegenerative diseases may therefore result in unwanted effects. PMID:23968537

  4. Mn-catalase (Alr0998) protects the photosynthetic, nitrogen-fixing cyanobacterium Anabaena PCC7120 from oxidative stress.

    PubMed

    Banerjee, Manisha; Ballal, Anand; Apte, Shree Kumar

    2012-11-01

    Role of the non-haem, manganese catalase (Mn-catalase) in oxidative stress tolerance is unknown in cyanobacteria. The ORF alr0998 from the Anabaena PCC7120, which encodes a putative Mn-catalase, was constitutively overexpressed in Anabaena PCC7120 to generate a recombinant strain, AnKat(+). The Alr0998 protein could be immunodetected in AnKat(+) cells and zymographic analysis showed a distinct thermostable catalase activity in the cytosol of AnKat(+) cells but not in the wild-type Anabaena PCC7120. The observed catalase activity was insensitive to inhibition by azide indicating that Alr0998 protein is indeed a Mn-catalase. In response to oxidative stress, the AnKat(+) showed reduced levels of intracellular ROS which was also corroborated by decreased production of an oxidative stress-inducible 2-Cys-Prx protein. Treatment of wild-type Anabaena PCC7120 with H(2)O(2) caused (i) RNA degradation in vivo, (ii) severe reduction of photosynthetic pigments and CO(2) fixation, (iii) fragmentation and lysis of filaments and (iv) loss of viability. In contrast, the AnKat(+) strain was protected from all the aforesaid deleterious effect under oxidative stress. This is the first report on protection of an organism from oxidative stress by overexpression of a Mn-catalase. PMID:22897147

  5. Role of. pi. -cation radicals in the enzymatic cycles of peroxidases, catalases, and nitrite and sulfite reductases

    SciTech Connect

    Hanson, L K; Chang, C K; Davis, M S; Fajer, J

    1980-01-01

    Charge iterative extended Hueckel calculations, and magnetic and optical results on porphyrins, chlorins, and isobacteriochlorins (1) suggest that the catalytic cycles of the enzymes horseradish peroxidase, catalase, Neurospora crassa catalase, and nitrite and sulfite reductases proceed via ..pi..-cation radicals of their prosthetic groups; (2) offer distinguishing features for the optical and magnetic spectra of these radicals, pertinent to their detection as enzymatic intermediates; (3) reconcile the seemingly contradictory optical and NMR data on Compounds I of horseradish peroxidase; and (4) predict that the axial ligation of the heme differs for horseradish peroxidase and catalase.

  6. Investigation of lipid peroxidation and catalase activity in magnetic fluid treated mice

    NASA Astrophysics Data System (ADS)

    Freitas, M. L. L.; Silva, L. P.; Freitas, J. L.; Azevedo, R. B.; Lacava, Z. G. M.; Homem de Bittencourt, P. I.; Curi, R.; Buske, N.; Morais, P. C.

    2003-05-01

    The increasing interest in magnetic fluids (MFs) for biomedical applications demands a deeper knowledge of their effects in biological systems. To evaluate the in vivo response of a MF sample based on magnetite nanoparticles stabilized by a precoating double layer of dodecanoic acid plus ethoxylated polyalcohol (MFDE), the inflammation-related oxidative stress and antioxidant tissue response were both addressed in this study. MFDE sample was intraperitoneally administrated to mice at three different doses. The lipid peroxidation and the antioxidant defense induced in the liver and spleen were evaluated, respectively, by thiobarbituric acid-reactive substances (TBARS) and catalase activity, 1, 14, and 28 days after MFDE treatment. The liver and spleen responded with a huge increase in TBARS after MFDE treatment. We observed that oxidative changes as well as the variations in the liver catalase activity were time and MFDE-dose dependent.

  7. A quantitative genetic analysis of tissue-specific catalase activity in Mus musculus

    Microsoft Academic Search

    Nicholas J. Schisler; Shiva M. Singh

    1991-01-01

    Tissue-specific catalase activity in 3-week-old animals from inbred mouse strains 129\\/ReJ, BALB\\/c, C3H\\/HeAnl\\/Cas-1b, C3H\\/HeSnJ, C3H\\/S, C57BL\\/6J, and Swiss-Webster was found to be highly variable by analysis of variance (P=0.01). Appropriate crosses were made among strains which were classified as normal (BALB\\/c, C3H\\/HeSnJ, C3H\\/S), hypocatalasemic (129\\/ReJ, C57BL\\/6J), and acatalasemic (C3H\\/HeAnl\\/Cas-1b) with respect to blood catalase activity to study the inheritance of

  8. MEASUREMENT OF SUPEROXIDE DISMUTASE, CATALASE, AND GLUTATHIONE PEROXIDASE IN CULTURED CELLS AND TISSUE

    PubMed Central

    Weydert, Christine J.; Cullen, Joseph J.

    2010-01-01

    Cells contain a large number of antioxidants to prevent or repair the damage caused by ROS, as well as to regulate redox-sensitive signaling pathways General protocols are described to measure the antioxidant enzyme activity of superoxide dismutase (SOD), catalase, and glutathione peroxidase. The SODs convert superoxide radical into hydrogen peroxide and molecular oxygen, while the catalase and peroxidases convert hydrogen peroxide into water. In this way, two toxic species, superoxide radical and hydrogen peroxide, are converted to the harmless product water. Western blots, activity gels and activity assays are various methods used to determine protein and activity in both cells and tissue depending on the amount of protein needed for each assay. Other techniques including immunohistochemistry and immunogold can further evaluate the levels of the various antioxidant enzymes in tissue and cells. In general, these assays require 24 to 48 hours to complete. PMID:20057381

  9. Compounds I of Catalase and Horse Radish Peroxidase: pi -cation Radicals

    Microsoft Academic Search

    D. Dolphin; A. Forman; D. C. Borg; J. Fajer; R. H. Felton

    1971-01-01

    Two-electron oxidation of cobaltous octa-ethylporphyrin [Co(II)(Et)8P] yields a stable pi -cation radical [Co(III)(Et)8P]2+\\\\cdot, the optical spectrum of which exhibits spectral changes dependent upon the nature of the counterion. Comparison of these spectra with those of Compounds I of horseradish peroxidase and catalase leads us to propose that these Compounds I contain a pi -cation radical of the heme prosthetic group.

  10. Roles of Catalase and Hydrogen Peroxide in Green Tea Polyphenol-Induced Chemopreventive Effects

    Microsoft Academic Search

    Tetsuya Yamamoto; Jill Lewis; John Wataha; Douglas Dickinson; Baldev Singh; Wendy B. Bollag; Eisaku Ueta; Tokio Osaki; Mohammad Athar; George Schuster; Stephen Hsu

    2003-01-01

    The green tea polyphenol ()-epigallocatechin-3-gallate (EGCG) possesses promising anticancer potential. Although in vivo stud- ies unveiled the metabolic routes and pharmacokinetics of EGCG and showed no adverse effects, in vitro studies at high concen- trations demonstrated oxidative stress. EGCG causes differential oxidative environments in tumor versus normal epithelial cells, but the roles that EGCG, hydrogen peroxide (H2O2), and intracellular catalase

  11. Catalase activity and rhythmic patterns in mouse brain, kidney and liver

    Microsoft Academic Search

    Mamane Sani; Hichem Sebaï; Wafa Gadacha; Naceur A. Boughattas; Alain Reinberg; Ben Attia Mossadok

    2006-01-01

    To protect tissues from damaging effects of reactive oxygen species (ROS), organisms possess enzymatic and non-enzymatic antioxidant systems. Cytosolic-enzyme catalase (CAT) is a component of the antioxidant defence system that reduces hydrogen peroxide (H2O2) to water (H2O). The aim of this study was to assess the variation of antioxidant enzyme CAT activity in brain, kidney and liver of adult male

  12. A superoxide dismutase mimetic with catalase activity (EUK-8) reduces the organ injury in endotoxic shock

    Microsoft Academic Search

    Michelle C. McDonald; Roberta d'Emmanuele di Villa Bianca; Nicole S. Wayman; Aldo Pinto; Martyn A. Sharpe; Salvatore Cuzzocrea; Prabal K. Chatterjee; Christoph Thiemermann

    2003-01-01

    Reactive oxygen species contribute to the multiple organ failure in endotoxic shock. Here, we investigate the effects of a salen-manganese complex, which exhibits both superoxide dismutase and catalase activity (EUK-8), on the circulatory failure, renal and liver injury and dysfunction caused by endotoxin in the anaesthetised rat. Endotoxaemia (6 mg\\/kg i.v., Escherichia coli lipopolysaccharide) for 6 h caused hypotension, renal

  13. Glutathione, Glutathione-Related Enzymes, and Catalase Activities in the Earthworm Eisenia fetida andrei

    Microsoft Academic Search

    M. Saint-Denis; F. Labrot; J. F. Narbonne; D. Ribera

    1998-01-01

    .   The aim of this work was to provide basic data on the antioxidant defences in the annelid Eisenia fetida andrei (E. f. a.). Methods for measurement of three antioxidant enzymes—catalase (CAT), glutathione peroxidase (GPX), and glutathione\\u000a reductase (GR)—and of glutathione-S-transferase (GST) were optimized. GPX activity differed according to the substrate used:\\u000a cumene hydroperoxide (CUOOH) or hydrogen peroxide (H2O2). The

  14. Adenovirus-mediated catalase gene transfer reduces oxidant stress in human, porcine and rat pancreatic islets

    Microsoft Academic Search

    P. Y. Benhamou; C. Moriscot; M. J. Richard; O. Beatrix; L. Badet; F. Pattou; J. Kerr-Conte; J. Chroboczek; P. Lemarchand; S. Halimi

    1998-01-01

    Summary   Susceptibility of pancreatic islets to oxidant stress may affect islet viability and contribute to primary non function of\\u000a allo- or xenogenic grafts. We investigated the influence of overexpression of catalase (CAT) on the viability of human, porcine\\u000a and rat islets, as well as INS-1 beta-cell line. Islets were transfected with a replication-deficient adenovirus vector containing\\u000a human CAT cDNA under

  15. Influence on Erythropoiesis and Blood Catalase Activity Low Intensity Electromagnetic Millimeter Radiation

    Microsoft Academic Search

    Ts. I. Adamyan; E. S. Gevorgyan; H. H. Hovhanisyan; S. M. Minasyan; V. P. Kalantaryan; A. A. Hakhoumian

    \\u000a The present study was undertaken to investigate changes of the blood catalase activity and regeneration processes in the circulatory\\u000a system of rabbits under conditions of bone-marrow deficiency and long-term exposure to lowpower extremely high frequency electromagnetic\\u000a radiation (EHF EMR) at frequency of 50.3 GHz. As it is known, this frequency is resonant for the vibrations of water hexagonal\\u000a structures[1]. During

  16. Adenovirus-Mediated Gene Transfer of Superoxide Dismutase and Catalase Decreases Restenosis after Balloon Angioplasty

    Microsoft Academic Search

    Eric Durand; Ayman Al Haj Zen; Faouzi Addad; Camille Brasselet; Giuseppina Caligiuri; François Vinchon; Patricia Lemarchand; Michel Desnos; Patrick Bruneval; Antoine Lafont

    2005-01-01

    Background: Reactive oxygen species (ROS) production increases after injury and potentially contributes to restenosis after angioplasty. We therefore evaluated the effect of adenovirus-mediated gene transfer (Ad) of superoxide dismutase (SOD) and catalase (CAT) on ROS production and restenosis after balloon angioplasty. Methods: O2– and H2O2 production was quantified in cultured cells after incubation with either LPS or CuSO4. Angioplasty and

  17. Hydrogen Peroxide Formation and Catalase Activity in the Lactic Acid Bacteria

    Microsoft Academic Search

    R. Whittenbury

    1964-01-01

    SUMMARY Some lactic acid bacteria formed detectable H202 and some did not, regardless of their preference or requirement for aerobic or anaerobic conditions. Whether or not H202 was formed depended in some instances on the substrate used as energy source. Two H202-splitting activities were encountered though never in the same organism. One, named pseudo- catalase activity, was insensitive to 0.01

  18. The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum.

    PubMed

    Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad

    2014-01-01

    Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis. PMID:24142360

  19. Cytochemical localization of peroxidatic activity of catalase in rat hepatic microbodies (peroxisomes).

    PubMed

    Fahimi, H D

    1969-11-01

    Prominent staining of rat hepatic microbodies was obtained by incubating sections of aldehyde-fixed rat liver in a modified Graham and Karnovsky's medium for ultrastructural demonstration of peroxidase activity. The electron-opaque reaction product was deposited uniformly over the matrix of the microbodies. The microbodies were identified by their size, shape, presence of tubular nucleoids, and other morphologic characteristics, and by their relative numerical counts. The staining reaction was inhibited by the catalase inhibitor, aminotriazole, and by KCN, azide, high concentrations of H(2)O(2), and by boiling of sections. These inhibition studies suggest that the peroxidatic activity of microbody catalase is responsible for the staining reaction. In the absence of exogenous H(2)O(2) appreciable staining of microbodies was noted only after prolonged incubation. Addition of sodium pyruvate, which inhibits endogenous generation of H(2)O(2) by tissue oxidases, or of crystalline catalase, which decomposes such tissue-generated H(2)O(2), completely abolished microbody staining in the absence of H(2)O(2). Neither diaminobenzidine nor the product of its oxidation had any affinity to bind nonenzymatically to microbody catalase and thus stain these organelles. The staining of microbodies was optimal at alkaline pH of 8.5. The biological significance of this alkaline pH in relation to the similar pH optima of several microbody oxidases is discussed. In addition to staining of microbodies, a heat-resistant peroxidase activity is seen in some of the peribiliary dense bodies. The relation of this reaction to the peroxidase activity of lipofuscin pigment granules is discussed. PMID:4186511

  20. Purification and characterization of a mesohalic catalase from the halophilic bacterium Halobacterium halobium.

    PubMed

    Brown-Peterson, N J; Salin, M L

    1995-01-01

    When subjected to the stress of growth in a relatively low-salt environment (1.25 M NaCl), the halophilic bacterium Halobacterium halobium induces a catalase. The protein has been purified to electrophoretic homogeneity and has an M(r) of 240,000 and a subunit size of approximately 62,000. The enzyme is active over a broad pH range of 6.5 to 10.0, with a peak in activity at pH 7.0. It has an isoelectric point of 4.0. This catalse, which is not readily reduced by dithionite, shows a Soret peak at 406 nm. Cyanide and azide inhibit the enzyme at micromolar concentrations, whereas maleimide is without effect. The addition of 20 mM 3-amino-1,2,4-triazole results in a 33% inhibition in enzymatic activity. The tetrameric protein binds NADP in a 1:1 ratio but does not peroxidize NADPH, NADH, or ascorbate. Although the enzymatic activity is maximal when assayed in a 50 mM potassium phosphate buffer with no NaCl, prolonged incubation in a buffer lacking NaCl results in inactive enzyme. Moreover, purification must be performed in the presence of 2 M NaCl. Equally as effective in retaining enzymatic function are NaCl, LiCl, KCl, CsCl, and NH4Cl, whereas divalent salts such as MgCl2 and CaCl2 result in the immediate loss of activity. The catalase is stained by pararosaniline, which is indicative of a glycosidic linkage. The Km for H2O2 is 60 mM, with inhibition observed at concentrations in excess of 90 mM. Thus, the mesohalic catalase purified from H. halobium seems to be similar to other catalases, except for the salt requirements, but differs markedly from the constitutive halobacterial hydroperoxidase. PMID:7814327

  1. NAFENOPIN-INDUCED HEPATIC MICROBODY (PEROXISOME) PROLIFERATION AND CATALASE SYNTHESIS IN RATS AND MICE

    Microsoft Academic Search

    JARNARDAN K. REDDY; DANIEL L. AZARNOFF; DONALD J. SVOBODA; JADA D. PRASAD

    Nafenopin (2-methyl-2(p-(1,2,3,4-tetrahydro-l-naphthyl)phenoxy)-propionic acid ; Su- 13437), a potent hypolipidemic compound, was administered in varying concentrations in ground Purina Chow to male and female rats, wild type (Csa strain) mice and acatalasemic (Csb strain) mice to determine the hepatic microbody proliferative and catalase-inducing effects . In all groups of animals, administration of nafenopin at dietary levels of 0 .125% and 0.25%

  2. Spectroscopy, calorimetry and molecular simulation studies on the interaction of catalase with copper ion.

    PubMed

    Hao, Fang; Jing, Mingyang; Zhao, Xingchen; Liu, Rutao

    2015-02-01

    In this research, the binding mechanism of Cu(2+) to bovine liver catalase (BLC) was studied by fluorescence spectroscopy, ultraviolet-visible (UV-vis) absorption spectroscopy, circular dichroism (CD) spectroscopy, isothermal titration calorimetry (ITC) and molecular docking methods. The cellar experiment was firstly carried out to investigate the inhibition effect of catalase. During the fluorescence quenching study, after correcting the inner filter effect (IFE), the fluorescence of BLC was found to be quenched by Cu(2+). The quenching mechanism was determined by fluorescence lifetime measurement, and was confirmed to be the dynamic mode. The secondary structure content of BLC was changed by the addition of Cu(2+), as revealed by UV-vis absorption and CD spectra, which further induces the decrease in BLC activity. Molecular simulation study indicates that Cu(2+) is located between two ?-sheets and two random coils of BLC near to the heme group, and interacts with His 74 and Ser 113 residues near a hydrophilic area. The decrease of ?-helix and the binding of His 74 are considered to be the major reason for the inhibition of BLC activity caused by Cu(2+). The ITC results indicate that the binding stoichiometry of Cu(2+) to catalase is 11.4. Moreover, the binding of Cu(2+) to BLC destroyed H-bonds, which was confirmed by the CD result. PMID:25618814

  3. Seed esterases, leucine aminopeptidases and catalases of species of the genus Gossypium.

    PubMed

    Cherry, J P; Katterman, F R; Endrizzi, J E

    1972-01-01

    Polyacrylamide and starch gel electrophoresis were used to analyze the isozyme makeup of three enzyme systems (esterases, leucine aminopeptidases and catalases) from the dormant seeds of twenty-nine species within the genus Gossypium.Isozyme variation was observed for all three enzymes between the species of the different genome groups. The within species polymorphism noted for the esterases was not observed for the leucine aminopeptidase and catalase patterns. In general, only minor qualitative banding pattern differences distinguished the A and B genome species, whereas, band variations were greatest between the more distantly related species in the C, D and E genomes. Gossypium longicalyx (F genome) showed an overall banding pattern unique to itself. The species of the genomes (C, D, E and F) removed from the postulated area of genetic origin (Southern Africa) also exhibited greater isozyme variability than that of the wild species of the A and B genomes, both located in Southern Africa.Synthetic mixtures of seed extracts from parent species of recently formed synthetic allopolyploids produced additive isozyme patterns for esterase, leucine aminopeptidase and catalase that were closely comparable to the zymograms produced by their hybrids. In contrast all three enzyme systems showed significant qualitative isozyme variations between the three natural allotetraploids, G. tomentosum, G. barbadense and G. hirsutum when compared to the zymograms of the synthetic mixtures of their alleged parental forms. PMID:24430982

  4. Turning points in the evolution of peroxidase-catalase superfamily: molecular phylogeny of hybrid heme peroxidases.

    PubMed

    Zámocký, Marcel; Gasselhuber, Bernhard; Furtmüller, Paul G; Obinger, Christian

    2014-12-01

    Heme peroxidases and catalases are key enzymes of hydrogen peroxide metabolism and signaling. Here, the reconstruction of the molecular evolution of the peroxidase-catalase superfamily (annotated in pfam as PF00141) based on experimentally verified as well as numerous newly available genomic sequences is presented. The robust phylogenetic tree of this large enzyme superfamily was obtained from 490 full-length protein sequences. Besides already well-known families of heme b peroxidases arranged in three main structural classes, completely new (hybrid type) peroxidase families are described being located at the border of these classes as well as forming (so far missing) links between them. Hybrid-type A peroxidases represent a minor eukaryotic subfamily from Excavates, Stramenopiles and Rhizaria sharing enzymatic and structural features of ascorbate and cytochrome c peroxidases. Hybrid-type B peroxidases are shown to be spread exclusively among various fungi and evolved in parallel with peroxidases in land plants. In some ascomycetous hybrid-type B peroxidases, the peroxidase domain is fused to a carbohydrate binding (WSC) domain. Both here described hybrid-type peroxidase families represent important turning points in the complex evolution of the whole peroxidase-catalase superfamily. We present and discuss their phylogeny, sequence signatures and putative biological function. PMID:24846396

  5. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity.

    PubMed Central

    Halaban, R; Moellmann, G

    1990-01-01

    Melanogenesis is regulated in large part by tyrosinase (monophenol monooxygenase; monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1), and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmented (Blt/Blt) coat versus the wild-type black (B/B). We show that the b locus codes for a glycoprotein with the activity of a catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase, EC 1.11.1.6) (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, we conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. Our studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the Blt mutation renders the protein susceptible to rapid proteolytic degradation. Images PMID:1693779

  6. How Does Catalase Release Nitric Oxide? A Computational Structure Activity Relationship Study

    PubMed Central

    Vankayala, Sai Lakshmana; Hargis, Jacqueline C.; Woodcock, H. Lee

    2013-01-01

    Hydroxyurea (HU) is the only FDA approved medication for treating sickle cell disease in adults. The primary mechanism of action is pharmacological elevation of nitric oxide (NO) levels which induces propagation of fetal hemoglobin. HU is known to undergo redox reactions with heme based enzymes like hemoglobin and catalase to produce NO. However, specific details about the HU based NO release remain unknown. Experimental studies indicate that interaction of HU with human catalase compound I produces NO. Presently, we combine flexible receptor-flexible substrate induced fit docking (IFD) with energy decomposition analyses to examine the atomic level details of a possible key step in the clinical conversion of HU to NO. Substrate binding modes of nine HU analogs with catalase compound I were investigated to determine the essential properties necessary for effective NO release. Three major binding orientations were found that provide insight into the possible reaction mechanisms for producing NO. Further results show that anion/radical intermediates produced as part of these mechanisms would be stabilized by hydrogen bonding interactions from distal residues His75, Asn148, Gln168, and oxoferryl-heme. These details will ideally contribute to both a clearer mechanistic picture and provide insights for future structure based drug design efforts. PMID:24087936

  7. Catalase-like activity of horseradish peroxidase: relationship to enzyme inactivation by H2O2.

    PubMed Central

    Hernández-Ruiz, J; Arnao, M B; Hiner, A N; García-Cánovas, F; Acosta, M

    2001-01-01

    H2O2 is the usual oxidizing substrate of horseradish peroxidase C (HRP-C). In the absence in the reaction medium of a one-electron donor substrate, H2O2 is able to act as both oxidizing and reducing substrate. However, under these conditions the enzyme also undergoes a progressive loss of activity. There are several pathways that maintain the activity of the enzyme by recovering the ferric form, one of which is the decomposition of H2O2 to molecular oxygen in a similar way to the action of catalase. This production of oxygen has been kinetically characterized with a Clark-type electrode coupled to an oxygraph. HRP-C exhibits a weak catalase-like activity, the initial reaction rate of which is hyperbolically dependent on the H2O2 concentration, with values for K(2) (affinity of the first intermediate, compound I, for H2O2) and k(3) (apparent rate constant controlling catalase activity) of 4.0 +/- 0.6 mM and 1.78 +/- 0.12 s(-1) respectively. Oxygen production by HRP-C is favoured at pH values greater than approx. 6.5; under similar conditions HRP-C is also much less sensitive to inactivation during incubations with H2O2. We therefore suggest that this pathway is a major protective mechanism of HRP-C against such inactivation. PMID:11171085

  8. Slow intracellular trafficking of catalase nanoparticles targeted to ICAM-1 protects endothelial cells from oxidative stress.

    PubMed

    Muro, Silvia; Cui, Xiumin; Gajewski, Christine; Murciano, Juan-Carlos; Muzykantov, Vladimir R; Koval, Michael

    2003-11-01

    Nanotechnologies promise new means for drug delivery. ICAM-1 is a good target for vascular immunotargeting of nanoparticles to the perturbed endothelium, although endothelial cells do not internalize monomeric anti-ICAM-1 antibodies. However, coupling ICAM-1 antibodies to nanoparticles creates multivalent ligands that enter cells via an amiloride-sensitive endocytic pathway that does not require clathrin or caveolin. Fluorescence microscopy revealed that internalized anti-ICAM nanoparticles are retained in a stable form in early endosomes for an unusually long time (1-2 h) and subsequently were degraded following slow transport to lysosomes. Inhibition of lysosome acidification by chloroquine delayed degradation without affecting anti-ICAM trafficking. Also, the microtubule disrupting agent nocodazole delayed degradation by inhibiting anti-ICAM nanoparticle trafficking to lysosomes. Addition of catalase to create anti-ICAM nanoparticles with antioxidant activity did not affect the mechanisms of nanoparticle uptake or trafficking. Intracellular anti-ICAM/catalase nanoparticles were active, because endothelial cells were resistant to H2O2-induced oxidative injury for 1-2 h after nanoparticle uptake. Chloroquine and nocodazole increased the duration of antioxidant protection by decreasing the extent of anti-ICAM/catalase degradation. Therefore, the unique trafficking pathway followed by internalized anti-ICAM nanoparticles seems well suited for targeted delivery of therapeutic enzymes to endothelial cells and may provide a basis for treatment of acute vascular oxidative stress. PMID:12878488

  9. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

    SciTech Connect

    Halaban, R.; Moellmann, G. (Yale Univ. School of Medicine, New Haven, CT (USA))

    1990-06-01

    Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B{sup lt}/B{sup lt}) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B{sup lt} mutation renders the protein susceptible to rapid proteolytic degradation.

  10. Radiation inactivation of proteins: temperature-dependent inter-protomeric energy transfer in ox liver catalase.

    PubMed

    Potier, M; Villemure, J F; Thauvette, L

    1994-03-15

    The radiation-inactivation method is widely used to determine the oligomeric structure of enzymes without need for solubilization or purification. We have used purified ox liver catalase, a tetrameric enzyme in solution, to study energy transfer between associated promoters responsible for oligomer inactivation. However, after freeze-drying the tetramer dissociates into an asymmetric dimer. In the present paper we compare both the radiation-inactivation size (obtained by following the activity decay) and the target size (obtained by measuring the amount of remaining protein by SDS/PAGE) of catalase under various states of aggregation and temperature. At -78 degrees C, only one promoter was fragmented after being hit by a gamma-ray and, as expected, this protomer was also inactivated. This result was obtained when either catalase was in tetrameric or in dimeric forms. However, at 38 degrees C, even though a single monomer was fragmented as at -78 degrees C, the whole dimer was inactivated. This result suggests that, at the higher temperature, there is a transfer of energy from the fragmented protomer to the other associated protomer, causing inactivation of the whole dimer. The inactivation of oligomeric enzymes is a two-step mechanism involving: (1) fragmentation of the hit monomer, followed by (2) temperature-dependent energy transfer from the fragmented towards the associated protomer. Thus we conclude that the radiation-inactivation size reflects the transfer of absorbed energy inside the oligomer which causes inactivation of one or several monomers. PMID:8141768

  11. Coordination modes of tyrosinate-ligated catalase-type heme enzymes: Magnetic circular dichroism studies of Plexaura homomalla allene oxide synthase, Mycobacterium avium ssp . Paratuberculosis protein-2744c, and bovine liver catalase in their ferric and ferrous states

    Microsoft Academic Search

    D. M. Indika Bandara; Masanori Sono; Grant S. Bruce; Alan R. Brash; John H. Dawson

    Bovine liver catalase (BLC), catalase-related allene oxide synthase (cAOS) from Plexaura homomalla, and a recently isolated protein from the cattle pathogen Mycobacterium avium ssp. paratuberculosis (MAP-2744c (MAP)) are all tyrosinate-ligated heme enzymes whose crystal structures have been reported. cAOS and MAP have low (<20%) sequence similarity to, and significantly different catalytic functions from, BLC. cAOS transforms 8R-hydroperoxy-eicosatetraenoic acid to an

  12. Specific Function of the Met-Tyr-Trp Adduct Radical and Residues Arg-418 and Asp-137 in the Atypical Catalase Reaction of Catalase-Peroxidase KatG*

    PubMed Central

    Zhao, Xiangbo; Khajo, Abdelahad; Jarrett, Sanchez; Suarez, Javier; Levitsky, Yan; Burger, Richard M.; Jarzecki, Andrzej A.; Magliozzo, Richard S.

    2012-01-01

    Catalase activity of the dual-function heme enzyme catalase-peroxidase (KatG) depends on several structural elements, including a unique adduct formed from covalently linked side chains of three conserved amino acids (Met-255, Tyr-229, and Trp-107, Mycobacterium tuberculosis KatG numbering) (MYW). Mutagenesis, electron paramagnetic resonance, and optical stopped-flow experiments, along with calculations using density functional theory (DFT) methods revealed the basis of the requirement for a radical on the MYW-adduct, for oxyferrous heme, and for conserved residues Arg-418 and Asp-137 in the rapid catalase reaction. The participation of an oxyferrous heme intermediate (dioxyheme) throughout the pH range of catalase activity is suggested from our finding that carbon monoxide inhibits the activity at both acidic and alkaline pH. In the presence of H2O2, the MYW-adduct radical is formed normally in KatG[D137S] but this mutant is defective in forming dioxyheme and lacks catalase activity. KatG[R418L] is also catalase deficient but exhibits normal formation of the adduct radical and dioxyheme. Both mutants exhibit a coincidence between MYW-adduct radical persistence and H2O2 consumption as a function of time, and enhanced subunit oligomerization during turnover, suggesting that the two mutations disrupting catalase turnover allow increased migration of the MYW-adduct radical to protein surface residues. DFT calculations showed that an interaction between the side chain of residue Arg-418 and Tyr-229 in the MYW-adduct radical favors reaction of the radical with the adjacent dioxyheme intermediate present throughout turnover in WT KatG. Release of molecular oxygen and regeneration of resting enzyme are thereby catalyzed in the last step of a proposed catalase reaction. PMID:22918833

  13. Purification, cloning, expression, and biochemical characterization of a monofunctional catalase, KatP, from Pigmentiphaga sp. DL-8.

    PubMed

    Dong, Weiliang; Hou, Ying; Li, Shuhuan; Wang, Fei; Zhou, Jie; Li, Zhoukun; Wang, Yicheng; Huang, Fei; Fu, Lei; Huang, Yan; Cui, Zhongli

    2015-04-01

    Catalases are essential components of the cellular equipment used to cope with oxidative stress. The monofunctional catalase KatP was purified from Pigmentiphaga sp. using ammonium sulfate precipitation (ASP), diethylaminoethyl ion exchange chromatography (IEC), and hydrophobic interaction chromatography (HIC). The purified catalase formed polymer with an estimated monomer molecular mass of 54kDa, which were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and zymogram analysis. KatP exhibited a specific catalytic activity of 73,000U/mg, which was higher than that of catalase-1 of Comamonas terrigena N3H (55,900U/mg). Seven short tryptic fragments of this catalase were obtained by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF MS/MS), and the gene, katP, was cloned by PCR amplification and overexpressed in Escherichia coli BL21 (DE3). Based on the complete amino acid sequence, KatP was identified as a clade 3 monofunctional catalase. The specific activities of recombinant KatP for hydrogen peroxide (690,000U/mg) increased 9-fold over that of the parent strain. The Km and Vmax of recombinant KatP were 9.48mM and 81.2mol/minmg, respectively. The optimal pH and temperature for KatP were 7.0 and 37°C, respectively, and the enzyme displayed abroad pH-stable range of 4.0-11.0. The enzyme was inhibited by Zn(2+), Cu(2+), Cr(2+), and Mn(2+), whereas Fe(3+) and Mg(2+) stimulated KatP enzymatic activity. Interestingly, the catalase activity of recombinant KatP displayed high stability under different temperature and pH conditions, suggesting that KatP is a potential candidate for the production of catalase. PMID:25665507

  14. Control of ceramide-induced apoptosis by IGF-1: involvement of PI3 kinase, caspase-3 and catalase

    Microsoft Academic Search

    T Kondo; T Kitano; K Iwai; M Watanabe; Y Taguchi; T Yabu; H Umehara; N Domae; T Uchiyama; T Okazaki

    2002-01-01

    Insulin-like growth factor-1 (IGF-1) inhibited N-acetylsphingosine (C2-ceramide)-induced HL-60 cell apoptosis via relieving oxidative damage. This inhibitory action of IGF-1 was blocked by a phosphatidylinositol-3 (PI-3) kinase inhibitor wortmannin and enhanced by overexpression of the p110 catalytic subunit of PI-3 kinase. Either IGF-1 pretreatment or PI-3 kinase overexpression restored ceramide-depleted catalase function, and this restoration was inhibited by wortmannin. A catalase

  15. Oxygen-Dependent Regulation of the Expression of the Catalase Gene katA of Lactobacillus sakei LTH677

    Microsoft Academic Search

    CHRISTIAN HERTEL; GUDRUN SCHMIDT; MARC FISCHER; KATJA OELLERS; WALTER P. HAMMES

    1998-01-01

    The catalase gene katA of Lactobacillus sakei LTH677 was cloned and expressed in Escherichia coli UM2, Lactobacillus casei LK1, and Lactobacillus curvatus LTH1432. The last host is a catalase-deficient plasmid-cured derivative of a starter organism used in meat fermentation. The regulation of katA expression was found to be the same in L. sakei LTH677 and the recombinant strains. The addition

  16. Catalase activity in macro- and microorganisms as an indicator of biotic stress in coastal waters of the eastern Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Angel, D. L.; Fiedler, U.; Eden, N.; Kress, N.; Adelung, D.; Herut, B.

    In this study we examined the activity of catalase in the water column (mainly attributed to planktonic microorganisms) and the activity of catalase and superoxide dismutase (SOD), as well as lipid peroxidation in the midgut gland of the benthic bivalve Donax trunculus as possible indicators of biotic stress. The measurements were performed at stations situated at known contaminated and clean sites in the coastal waters and shores along the Israeli coast (eastern Mediterranean Sea). In the water column, we found that catalase activity was higher in polluted coastal waters than in nearby unpolluted or less-polluted stations. Moreover, there was diurnal periodicity in catalase activity rates which matched the diurnal changes in hydrogen peroxide levels in seawater. Consistent evidence of extracellular catalase activity was found in the seawater sampled. Catalase activity rates in the midgut gland of D. trunculus did not exhibit clear patterns with respect to site (polluted or clean) or season. However, SOD activity and lipid peroxidation measured in the same tissues were good indicators of organic pollution in the coastal waters examined and, among the three stations examined in Haifa Bay, Qiriat Haim was the most polluted.

  17. Investigating catalase activity through hydrogen peroxide decomposition by bacteria biofilms in real time using scanning electrochemical microscopy.

    PubMed

    Abucayon, Erwin; Ke, Neng; Cornut, Renaud; Patelunas, Anthony; Miller, Douglas; Nishiguchi, Michele K; Zoski, Cynthia G

    2014-01-01

    Catalase activity through hydrogen peroxide decomposition in a 1 mM bulk solution above Vibrio fischeri (?-Protebacteria-Vibrionaceae) bacterial biofilms of either symbiotic or free-living strains was studied in real time by scanning electrochemical microscopy (SECM). The catalase activity, in units of micromoles hydrogen peroxide decomposed per minute over a period of 348 s, was found to vary with incubation time of each biofilm in correlation with the corresponding growth curve of bacteria in liquid culture. Average catalase activity for the same incubation times ranging from 1 to 12 h was found to be 0.28 ± 0.07 ?mol H2O2/min for the symbiotic biofilms and 0.31 ± 0.07 ?mol H2O2/min for the free-living biofilms, suggesting similar catalase activity. Calculations based on Comsol Multiphysics simulations in fitting experimental biofilm data indicated that approximately (3 ± 1) × 10(6) molecules of hydrogen peroxide were decomposed by a single bacterium per second, signifying the presence of a highly active catalase. A 2-fold enhancement in catalase activity was found for both free-living and symbiotic biofilms in response to external hydrogen peroxide concentrations as low as 1 nM in the growth media, implying a similar mechanism in responding to oxidative stress. PMID:24328342

  18. Two temporally synthesized charge subunits interact to form the five isoforms of cottonseed (Gossypium hirsutum) catalase.

    PubMed

    Ni, W; Trelease, R N; Eising, R

    1990-07-01

    Five charge isoforms of tetrameric catalase were isolated from cotyledons of germinated cotton (Gossypium hirsutum L.) seedlings. Denaturing isoelectric focusing of the individual isoforms in polyacrylamide gels indicated that isoforms A (most anodic) and E (most cathodic) consisted of one subunit of different charge, whereas isoforms B, C and D each consisted of a mixture of these two subunits. Thus the five isoforms apparently were formed through combinations of two subunits in different ratios. Labelling cotyledons in vivo with [35S]methionine at three daily intervals in the dark, and translation in vivo of polyadenylated RNA isolated from cotyledons at the same ages, revealed synthesis of two different subunits. One of the subunits was synthesized in cotyledons at all ages studied (days 1-3), whereas the other subunit was detected only at days 2 and 3. This differential expression of two catalase subunits helped explain previous results from this laboratory showing that the two anodic forms (A and B) found in maturing seeds were supplemented with three cathodic forms (C-E) after the seeds germinated. These subunit data also helped clarify our new findings that proteins of isoforms A, B and C (most active isoforms) accumulated in cotyledons of plants kept in the dark for 3 days, then gradually disappeared during the next several days, whereas isoforms D and E (least active isoforms) remained in the cells. This shift in isoform pattern occurred whether seedlings were kept in the dark or exposed to continuous light after day 3, although exposure to light enhanced this process. These sequential molecular events were responsible for the characteristic developmental changes (rise and fall) in total catalase activity. We believe that the isoform changeover is physiologically related to the changeover in glyoxysome to leaf-type-peroxisome metabolism. PMID:1695843

  19. The reaction mechanisms of heme catalases: an atomistic view by ab initio molecular dynamics.

    PubMed

    Alfonso-Prieto, Mercedes; Vidossich, Pietro; Rovira, Carme

    2012-09-15

    Catalases are ubiquitous enzymes that prevent cell oxidative damage by degrading hydrogen peroxide to water and oxygen (2H(2)O(2) ? 2H(2)O+O(2)) with high efficiency. The enzyme is first oxidized to a high-valent iron intermediate, known as Compound I (Cpd I, Por(·+)-Fe(IV)=O) which, at difference from other hydroperoxidases, is reduced back to the resting state by further reacting with H(2)O(2). The normal catalase activity is reduced if Cpd I is consumed in a competing side reaction, forming a species named Cpd I*. In recent years, Density Functional Theory (DFT) methods have unraveled the electronic configuration of these high-valent iron species, helping to assign the intermediates trapped in the crystal structures of oxidized catalases. It has been demonstrated that the a priori assumption that the H(+)/H(-) type of mechanism for Cpd I reduction leads to the generation of singlet oxygen is not justified. Moreover, it has been shown by ab initio metadynamics simulations that two pathways are operative for Cpd I reduction: a His-mediated mechanism (described as H·/H(+) + e(-)) in which the distal His acts as an acid-base catalyst and a direct mechanism (described as H·/H·) in which the distal His does not play a direct role. Independently of the mechanism, the reaction proceeds by two one-electron transfers rather than one two-electron transfer, as previously assumed. Electron transfer to Cpd I, regardless of whether the electron is exogenous or endogenous, facilitates protonation of the oxoferryl group, to the point that formation of Cpd I* may be controlled by the easiness of protonation of reduced Cpd I. PMID:22516655

  20. Dynamics of the reaction glucose-catalase-glucose oxidase-hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    ?íp, M.; Schreiberová, L.; Schreiber, I.

    2011-12-01

    Glucose-catalase-glucose oxidase-hydrogen peroxide reaction is one of the few known enzymatic systems studied in vitro in the field of nonlinear chemical dynamics. This reaction belongs to the family of oscillatory enzymatic reactions, which form a natural basis of oscillations in biological systems. A parametric study of dependence on mixing, temperature and initial concentrations of components in a batch stirred reactor was carried out. A newly proposed mathematical model of the reaction conforms to the obtained experimental data. Results of our experiments and simulations hint at further directions of research of non-linear dynamics in this reaction.

  1. Draft genomic DNA sequence of strain Halomonas sp. FS-N4 exhibiting high catalase activity.

    PubMed

    Pan, Jie; Abulaizi, Ailiman; Sun, Cong; Cheng, Hong; Wu, Min

    2014-12-01

    Halomonas sp. FS-N4 is a bacterium, which can grow in the medium Marine Broth 2216 with 5M initial hydrogen peroxide concentration, shows a strong oxidation resistance, and the crude enzyme activity can reach as high as 13.33katal/mg. We reported the draft genome sequence of H. sp. FS-N4, showing that it contains 3434 protein-coding genes, including the genes putatively involved in the response to the oxidative stress, among which a phytochrome-like gene might be a key point to survive in the environment with high concentration of hydrogen peroxide and exhibit high catalase activity. PMID:25176559

  2. X-ray diffraction study of Penicillium Vitale catalase in the complex with aminotriazole

    SciTech Connect

    Borovik, A. A.; Grebenko, A. I.; Melik-Adamyan, V. R., E-mail: mawr@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2011-07-15

    The three-dimensional structure of the enzyme catalase from Penicillium vitale in a complex with the inhibitor aminotriazole was solved and refined by protein X-ray crystallography methods. An analysis of the three-dimensional structure of the complex showed that the inhibition of the enzyme occurs as a result of the covalent binding of aminotriazole to the amino-acid residue His64 in the active site of the enzyme. An investigation of the three-dimensional structure of the complex resulted in the amino-acid residues being more precisely identified. The binding sites of saccharide residues and calcium ions in the protein molecule were found.

  3. Purification and characterization of a catalase-peroxidase from the photosynthetic bacterium Rhodopseudomonas capsulata.

    PubMed

    Hochman, A; Shemesh, A

    1987-05-15

    Catalase-peroxidase was isolated from aerobically grown Rhodopseudomonas capsulata. The enzyme resembles typical catalases in some of its physicochemical properties. It has an apparent molecular weight of 236,000 and is composed of four identical subunits. It shows a typical high spin ferric heme spectrum with absorption maxima at 403 and 635 nm and shoulders at 503 and 535 nm. Upon binding of cyanide, the enzyme is converted to the low spin state, as shown by the shift of the Soret maximum to 418 nm and the band at 532 nm. It has an isoelectric point at pH 4.5. The enzyme differs from typical catalases in also having a strong peroxidatic activity with dianisidine, pyrogallol, and diaminobenzidine as electron donors. Both the catalatic and the peroxidatic activities are similarly inactivated by treatment with 1 mM H2O2, heating to 50 degrees C, exposure to ethanol/chloroform, and photooxidative conditions. In contrast to typical catalases, but similarly to peroxidases, the enzyme is reduced by sodium dithionite. The pH optimum of the peroxidatic activity is 5-5.3 (in contrast to 6-6.5 of the catalatic activity). 50% of the apparent maximal activities are reached at 0.3 and 4.2 mM H2O2 for the peroxidatic and catalatic activities, respectively. Both enzymic activities are equally inhibited by cyanide, 50% inhibition being achieved with 2.2 X 10(-5) M KCN. Contrarily, the two activities differ in their response to hydroxylamine and azide. 50% inhibition of the catalatic activity is obtained with 1.5 X 10(-4) M azide or 2.15 X 10(-6) M hydroxylamine; 50% inhibition of the peroxidatic activity requires 7.3 X 10(-4) M azide or 7.8 X 10(-5) M hydroxylamine. The activation energies of the catalatic and the peroxidatic activities are 1.9 and 1.7 kcal/mol, respectively. PMID:3571290

  4. Cardiac-specific catalase overexpression rescues anthrax lethal toxin-induced cardiac contractile dysfunction: role of oxidative stress and autophagy

    PubMed Central

    2012-01-01

    Background Lethal and edema toxins secreted by Bacillus anthracis during anthrax infection were found to incite serious cardiovascular complications. However, the underlying mechanisms in anthrax lethal toxin-induced cardiac anomalies remain unknown. This study was designed to evaluate the impact of antioxidant enzyme catalase in anthrax lethal toxin-induced cardiomyocyte contractile dysfunction. Methods Wild type (WT) and cardiac-specific catalase overexpression mice were challenged with lethal toxin (2 ?g/g, intraperotineally (i.p.)). Cardiomyocyte contractile and intracellular Ca2+ properties were assessed 18 h later using an IonOptix edge-detection system. Proteasome function was assessed using chymotrypsin-like and caspase-like activities. GFP-LC3 puncta and Western blot analysis were used to evaluate autophagy and protein ubiquitination. Results Lethal toxin exposure suppressed cardiomyocyte contractile function (suppressed peak shortening, maximal velocity of shortening/re-lengthening, prolonged duration of shortening/re-lengthening, and impaired intracellular Ca2+ handling), the effects of which were alleviated by catalase. In addition, lethal toxin triggered autophagy, mitochondrial and ubiquitin-proteasome defects, the effects of which were mitigated by catalase. Pretreatment of cardiomyocytes from catalase mice with the autophagy inducer rapamycin significantly attenuated or ablated catalase-offered protection against lethal toxin-induced cardiomyocyte dysfunction. On the other hand, the autophagy inhibitor 3-MA ablated or significantly attenuated lethal toxin-induced cardiomyocyte contractile anomalies. Conclusions Our results suggest that catalase is protective against anthrax lethal toxin-induced cardiomyocyte contractile and intracellular Ca2+ anomalies, possibly through regulation of autophagy and mitochondrial function. PMID:23134810

  5. Immunohistochemical localization and biochemical changes in catalase and superoxide dismutase during metamorphosis in the olfactory system of frog Microhyla ornata.

    PubMed

    Gaupale, Tekchand C; Londhe, Jayant; Ghaskadbi, Saroj; Subhedar, N K; Bhargava, Shobha

    2012-02-01

    Amphibian metamorphosis is characterized by rapid tissue remodeling and drastic changes in the body structure and function. Like other organs, olfactory system also undergoes a dramatic rearrangement as the animal experiences transition from aquatic to terrestrial habitat. Reactive oxygen species (ROS) are known to play an important role during anuran metamorphosis and role of antioxidant enzymes like catalase and superoxide dismutase (SOD) are believed to play a major role in these processes. Therefore, we hypothesize that antioxidant enzymes in the olfactory system may undergo changes that reflect metamorphic processes. Immunohistochemical study revealed the presence of catalase and SOD in the olfactory receptor neurons and also granular reaction in olfactory epithelium of medial diverticulum during metamorphosis. Catalase and SOD immunoreactivity were seen in the epithelium of lateral diverticulum, vomeronasal organ as metamorphosis proceeds and in the apical lining of olfactory epithelium of adult frog. Biochemical study showed that catalase activity gradually increases in the olfactory system from metamorphic stage 40-46 and adult, while SOD activity decreases from stage 40 to 46 and increases in adult. Thus, the localization and relative levels of catalase and SOD during metamorphosis in the olfactory system suggests that these enzymes may be involved in protection from oxidative damage. PMID:22134050

  6. Uncaria tomentosa extracts protect human erythrocyte catalase against damage induced by 2,4-D-Na and its metabolites.

    PubMed

    Bukowska, Bo?ena; Bors, Milena; Gulewicz, Krzysztof; Koter-Michalak, Maria

    2012-06-01

    The effect of ethanolic and aqueous extracts from leaves and bark of Uncaria tomentosa was studied, with particular attention to catalase activity (CAT - EC. 1.11.1.6). We observed that all tested extracts, at a concentration of 250 ?g/mL were not toxic to erythrocyte catalase because they did not decreased its activity. Additionally, we investigated the protective effect of extracts on changes in CAT activity in the erythrocytes incubated with sodium salt of 2,4-dichlorophenoxyacetic acid (2,4-D-Na) and its metabolites i.e., 2,4-dichlorophenol (2,4-DCP) and catechol. Previous investigations showed that these chemicals decreased activity of erythrocyte catalase (Bukowska et al., 2000; Bukowska and Kowalska, 2004). The erythrocytes were divided into two portions. The first portion was incubated for 1 and 5h at 37°C with 2,4-D-Na, 2,4-DCP and catechol, and second portion was preincubated with extracts for 10 min and then incubated with xenobiotics for 1 and 5h. CAT activity was measured in the first and second portion of the erythrocytes. We found a protective effect of the extracts from U. tomentosa on the activity of catalase incubated with xenobiotics studied. Probably, phenolic compounds contained in U. tomentosa scavenged free radicals, and therefore protected active center (containing -SH groups) of catalase. PMID:22426356

  7. Salicylic acid and salicylic acid sensitive and insensitive catalases in different genotypes of chickpea against Fusarium oxysporum f. sp. ciceri.

    PubMed

    Gayatridevi, S; Jayalakshmi, S K; Mulimani, V H; Sreeramulu, K

    2013-10-01

    Differential expression of catalase isozymes in different genotypes of chickpea resistant genotypes- A1, JG-315, JG-11, WR-315, R1-315, Vijaya, ICCV-15017, GBS-964, GBM-10, and susceptible genotypes- JG-62, MNK, ICCV-08321, ICCV-08311, KW-104, ICCV-08123, ICC-4951, ICC-11322, ICC-08116 for wilt disease caused by Fusarium oxysporum. f. sp. ciceri (Foc) was analyzed. Salicylic acid (SA) and H2O2 concentrations were determined in control as well as in plants infected with F. ciceri and found that the high and low levels of salicylic acid and H2O2 in resistant and susceptible genotypes of chickpea respectively. Catalase isozyme activities were detected in the gel and found that no induction of new catalases was observed in all the resistant genotypes and their some of the native catalase isozymes were inhibited; whereas, induction of multiple catalase isozymes was observed in all the screened susceptible genotypes and their activities were not inhibited upon Foc or SA treatments. The above results support the possible role of these isozymes as a marker to identify which genotype of chickpea is expressing systemic acquired resistance. PMID:24431522

  8. Two independent peroxisomal targeting signals in catalase A of Saccharomyces cerevisiae

    PubMed Central

    1993-01-01

    In contrast to many other peroxisomal proteins catalase A contains at least two peroxisomal targeting signals each sufficient to direct reporter proteins to peroxisomes. One of them resides at the extreme carboxy terminus constituting a new variant of this signal, -SSNSKF, not active in monkey kidney cells (Gould, S. J., G. A. Keller, N. Hosken, J. Wilkinson, and S. Subramani 1989. J. Cell Biol. 108:1657- 1664). However, this signal is completely dispensable for import of catalase A itself. In its amino-terminal third this protein contains another peroxisomal targeting signal sufficient to direct reporter proteins into microbodies. This internal signal depends on the context. The nature of this targeting signal might be a short defined sequence or a structural feature recognized by import factors. In addition, we have demonstrated that the carboxy-terminal seven amino acids of citrate synthase of Saccharomyces cerevisiae encoded by CIT2 and containing the canonical -SKL represents a targeting signal sufficient to direct reporter proteins to peroxisomes. PMID:8425895

  9. Mutations in the catalase-peroxidase gene from isoniazid-resistant Mycobacterium tuberculosis isolates.

    PubMed

    Altamirano, M; Marostenmaki, J; Wong, A; FitzGerald, M; Black, W A; Smith, J A

    1994-05-01

    Isoniazid resistance in Mycobacterium tuberculosis has been associated with total deletion of the katG gene, which codes for catalase-peroxidase production. To determine whether this is a common mechanism of drug resistance, 9 isolates of isoniazid-resistant and 1 of isoniazid-sensitive M. tuberculosis were analyzed by polymerase chain reaction amplification of a 237-bp sequence of the katG gene. Amplification was observed in the isoniazid-sensitive isolate and in 8 resistant isolates; in only 1 isoniazid-resistant isolate was there no amplification of the expected band, suggesting gene deletion. DNA sequencing showed that 8 of the 9 isolates had point mutations, deletions, or insertions of 1-3 bases. Evidence corroborating the presence of mutations in the katG gene was obtained by single-strand conformation polymorphism analysis in these 8 isolates. Thus, mutations as well as insertions and deletions in the katG gene can account for inactive catalase peroxidase, leading to isoniazid resistance; gene deletion occurs only infrequently, in approximately 11% of cases. PMID:8169415

  10. Copper suppresses abscisic acid catabolism and catalase activity, and inhibits seed germination of rice.

    PubMed

    Ye, Nenghui; Li, Haoxuan; Zhu, Guohui; Liu, Yinggao; Liu, Rui; Xu, Weifeng; Jing, Yu; Peng, Xinxiang; Zhang, Jianhua

    2014-11-01

    Although copper (Cu) is an essential micronutrient for plants, a slight excess of Cu in soil can be harmful to plants. Unfortunately, Cu contamination is a growing problem all over the world due to human activities, and poses a soil stress to plant development. As one of the most important biological processes, seed germination is sensitive to Cu stress. However, little is known about the mechanism of Cu-induced inhibition of seed germination. In the present study, we investigated the relationship between Cu and ABA which is the predominant regulator of seed germination. Cu at a concentration of 30 µM effectively inhibited germination of rice caryopsis. ABA content in germinating seeds under copper stress was also higher than that under control conditions. Quantitative real-time PCR (qRT-PCR) revealed that Cu treatment reduced the expression of OsABA8ox2, a key gene of ABA catabolism in rice seeds. In addition, both malondialdehyde (MDA) and H2O2 contents were increased by Cu stress in the germinating seeds. Antioxidant enzyme assays revealed that only catalase activity was reduced by excess Cu, which was consistent with the mRNA profile of OsCATa during seed germination under Cu stress. Together, our results demonstrate that suppression of ABA catabolism and catalase (CAT) activity by excess Cu leads to the inhibition of seed germination of rice. PMID:25273891

  11. Catalase activity as a biomarker for mild-stress-induced robustness in Bacillus weihenstephanensis.

    PubMed

    den Besten, Heidy M W; Effraimidou, Styliani; Abee, Tjakko

    2013-01-01

    Microorganisms are able to survive and grow in changing environments by activating stress adaptation mechanisms which may enhance bacterial robustness. Stress-induced enhanced robustness complicates the predictability of microbial inactivation. Using psychrotolerant Bacillus weihenstephanensis strain KBAB4 as a model, we investigated the impact of the culturing temperature on mild-oxidative-stress-induced (cross-)protection toward multiple stresses, including severe oxidative, heat, and acid stresses. Culturing at a refrigeration temperature (7°C) compared to the optimal growth temperature (30°C) affected both the robustness level of B. weihenstephanensis and the oxidative stress adaptive response. Scavengers of reactive oxygen species have a crucial role in adaptation to oxidative stresses, and this points to a possible predictive role in mild-oxidative-stress-induced robustness. Therefore, the catalase activity was determined upon mild oxidative stress treatment and was demonstrated to be significantly correlated with the robustness level of mild-stress-treated cells toward severe oxidative and heat stresses but not toward severe acid stress for cells grown at both refrigeration and optimal temperatures. The quantified correlations supported the predictive quality of catalase activity as a biomarker and also underlined that the predictive quality is stress specific. Biomarkers that are able to predict stress-induced enhanced robustness can be used to better understand stress adaptation mechanisms and might allow the design of effective combinations of hurdles to control microbial behavior. PMID:23064331

  12. Temperature-Dependent Requirement for Catalase in Aerobic Growth of Listeria monocytogenes F2365?

    PubMed Central

    Azizoglu, Reha Onur; Kathariou, Sophia

    2010-01-01

    Listeria monocytogenes is a Gram-positive, psychrotrophic, facultative intracellular food-borne pathogen responsible for severe illness (listeriosis). The bacteria can grow in a wide range of temperatures (1 to 45°C), and low-temperature growth contributes to the food safety hazards associated with contamination of ready-to-eat foods with this pathogen. To assess the impact of oxidative stress responses on the ability of L. monocytogenes to grow at low temperatures and to tolerate repeated freeze-thaw stress (cryotolerance), we generated and characterized a catalase-deficient mutant of L. monocytogenes F2365 harboring a mariner-based transposon insertion in the catalase gene (kat). When grown aerobically on blood-free solid medium, the kat mutant exhibited impaired growth, with the extent of impairment increasing with decreasing temperature, and no growth was detected at 4°C. Aerobic growth in liquid was impaired at 4°C, especially under aeration, but not at higher temperatures (10, 25, or 37°C). Genetic complementation of the mutant with the intact kat restored normal growth, confirming that inactivation of this gene was responsible for the growth impairment. In spite of the expected impact of oxidative stress responses on cryotolerance, cryotolerance of the kat mutant was not affected. PMID:20817809

  13. [Effect of afobazole on the accumulation of free radical oxidation products and the catalase activity in rats with cerebral ischemia].

    PubMed

    Silkina, I V; Zenina, T A; Seredenin, S B; Mirzoian, R S

    2006-01-01

    The influence of afobazole on the accumulation of free radical oxidation products (reactive oxygen species, ROS) and on the activity of antioxidative enzyme catalase was studied in striatum and cortex of rats under cerebral ischemia damage conditions. Afobazole showed a tendency to decrease the extent of ROS accumulation in the cortex. In striatum, the intensity of ROS accumulation in rats after ischemia wasa reliably lower as compared to that in control rats, but afobazole produced a partial recovery of this parameter. Afobazole induced an increase in the catalase activity in the cortex of rats with ischemia. In contrast, afobazole did not change the activity of this enzyme in striatum (where it was also decreased by ischemia). Thus, afobazole increased the resistance of neuron membrane structures to free radical oxidation in cortex and striatum and stimulated the catalase activity in the cortex in rats with global reversible cerebral ischernia. PMID:16995439

  14. Upregulation of adenosine kinase in Rasmussen encephalitis.

    PubMed

    Luan, Guoming; Gao, Qing; Guan, Yuguang; Zhai, Feng; Zhou, Jian; Liu, Changqing; Chen, Yin; Yao, Kun; Qi, Xueling; Li, Tianfu

    2013-11-01

    Rasmussen encephalitis (RE) is a rare neurologic disorder of childhood characterized by unihemispheric inflammation, progressive neurologic deficits, and intractable focal epilepsy. The pathogenesis of RE is still enigmatic. Adenosine is a key endogenous signaling molecule with anticonvulsive and anti-inflammatory effects, and our previous work demonstrated that dysfunction of the adenosine kinase (ADK)-adenosine system and astrogliosis are the hallmarks of epilepsy. We hypothesized that the epileptogenic mechanisms underlying RE are related to changes in ADK expression and that those changes might be associated with the development of epilepsy in RE patients. Immunohistochemistry was used to examine the expression of ADK and glial fibrillary acidic protein in surgically resected human epileptic cortical specimens from RE patients (n = 12) and compared with control cortical tissues (n = 6). Adenosine kinase expression using Western blot and enzymatic activity for ADK were assessed in RE versus control samples. Focal astrogliosis and marked expression of ADK were observed in the lesions of RE. Significantly greater ADK expression in RE versus controls was demonstrated by Western blot, and greater enzymatic activity for ADK was demonstrated using an enzyme-coupled bioluminescent assay. These results suggest that upregulation of ADK is a common pathologic hallmark of RE and that ADK might be a target in the treatment of epilepsy associated with RE. PMID:24128682

  15. Improved membrane filtration method incorporating catalase and sodium pyruvate for detection of chlorine-stressed coliform bacteria.

    PubMed Central

    Calabrese, J P; Bissonnette, G K

    1990-01-01

    In vitro pure culture studies were conducted on three different strains of Escherichia coli (K-12, EPA 00244, and SWEI) to determine the effect of chlorination on catalase activity. In each case, stationary-phase cells exhibited significant (P less than 0.001) reductions in enzyme activity following exposure to chlorine. Mean differences in activity between control and chlorine-stressed cells ranged from 8.8 to 20.3 U/mg of protein for E. coli SWEI and EPA 00244, respectively. Following initial enzyme studies, resuscitation experiments utilizing the membrane filtration technique were conducted on chlorinated sewage effluent. Five different amendments, including catalase (1,000 U per plate), heat-inactivated catalase (1,000-U per plate), sodium pyruvate (0.05%), a catalase-sodium pyruvate combination (1,500 U/0.01%), and acetic acid (0.05%), were tested for the ability to enhance detection of chlorine-stressed cells on M-fecal coliform (M-FC), mT7, M-Endo, and tryptone-glucose-yeast extract (TGY) media. Significant (P less than 0.001) increases in recovery of fecal coliforms on M-FC, total coliforms on mT7 and M-Endo, and total heterotrophs on TGY were obtained on plates containing catalase, pyruvate, or the combination of these compounds. Supplementation with heat-inactivated catalase and acetic acid did not improve recovery of chlorine-stressed cells compared with recovery on nonamended media. Subsequent analysis of colonies from plates containing compounds which enhanced recovery indicated coliform verification percentages of greater than 80% on M-FC, greater than 90% on mT7, and greater than 94% on M-Endo media. These data suggest that the addition of peroxide-degrading compounds to various standard recovery media may improve detection of both coliform and heterotrophic bacteria in chlorinated waters. PMID:2268162

  16. Two catalase homologs are involved in host protection against bacterial infection and oxidative stress in Crassostrea hongkongensis.

    PubMed

    Zhang, Yang; Fu, Dingkun; Yu, Feng; Liu, Qiongyou; Yu, Ziniu

    2011-12-01

    Catalase is one of the key antioxidant enzymes and it appears to be involved in protection against immune infection and oxidative stress. Here, two catalase cDNAs (ChCat-1 and ChCat-2) were isolated from hemocytes of Crassostrea hongkongensis using SSH and RACE. The full-length cDNAs of ChCat-1 and ChCat-2 are 1913 and 2466 bp in length, encoding proteins of 515 and 511 amino acids, respectively. Multiple alignments of amino acid sequences revealed that both ChCat-1 and ChCat-2 possess several characteristic features of the catalase family of enzymes, including one proximal active site signature, one heme-ligand signature, and three catalytic amino acid residues (His(72), Asn(145) and Tyr(355)). Phylogenetic analysis indicates that these two catalases may share a common ancestral gene and result from a gene duplication event following the divergence of bivalves and gastropods. Constitutive expression of ChCat-1 and ChCat-2 was observed in all tissues studied, with highest levels of expression in gill and muscle, respectively. The expression of both genes was inducible by bacterial infection, and reached the maximum at 8 h (9.0-fold) and 12 h (2.3-fold) post-infection, respectively. Furthermore, both the purified ChCat-1 and ChCat-2 protein displayed a strong catalase activity, and S2 cells carrying ChCat-1 or ChCat-2 showed a higher degree of resistance to H(2)O(2) than that of control cells. In a word, this is the first report of the presence of two catalase genes in a single marine bivalve, and our results highlight the involvement of both ChCat-1 and ChCat-2 in host protection against pathogen infection and oxidative stress in C. hongkongensis. PMID:21871567

  17. Nox1 upregulates the function of vascular T-type calcium channels following chronic nitric oxide deficit.

    PubMed

    Howitt, Lauren; Matthaei, Klaus I; Drummond, Grant R; Hill, Caryl E

    2015-04-01

    Cardiovascular disease is characterised by reduced nitric oxide bioavailability resulting from oxidative stress. Our previous studies have shown that nitric oxide deficit per se increases the contribution of T-type calcium channels to vascular tone through increased superoxide from NADPH oxidase (Nox). The aim of the present study was therefore to identify the Nox isoform responsible for modulating T-type channel function, as T-type channels are implicated in several pathophysiological conditions involving oxidative stress. We evaluated T-channel function in skeletal muscle arterioles in vivo, using a novel T-channel blocker, TTA-A2 (3 ?mol/L), which demonstrated no cross reactivity with L-type channels. Wild-type and Nox2 knockout (Nox2ko) mice were treated with the nitric oxide synthase inhibitor L-NAME (40 mg/kg/day) for 2 weeks. L-NAME treatment significantly increased systolic blood pressure and the contribution of T-type calcium channels to arteriolar tone in wild-type mice, and this was not prevented by Nox2 deletion. In Nox2ko mice, pharmacological inhibition of Nox1 (10 ?mol/L ML171), Nox4 (10 ?mol/L VAS2870) and Nox4-derived hydrogen peroxide (500 U/mL catalase) significantly reduced the effect of chronic nitric oxide inhibition on T-type channel function. In contrast, in wild-type mice, ML171 and VAS2870, but not catalase, reduced the contribution of T-type channels to vascular tone, suggesting a role for Nox1 and non-selective actions of VAS2870. We conclude that Nox1, but not Nox2 or Nox4, is responsible for the upregulation of T-type calcium channels elicited by chronic nitric oxide deficit. These data point to an important role for this isoform in increasing T-type channel function during oxidative stress. PMID:24923576

  18. Ethanol-stimulated behaviour in mice is modulated by brain catalase activity and H 2 O 2 rate of production

    Microsoft Academic Search

    Raffll Pastor; Carles Sanchis-Segura; Carlos M. G. Aragon

    2002-01-01

      Abstract\\u000a \\u000a \\u000a Rationale. Over the last few years, a role for the brain catalase-H2O2 enzymatic system has been suggested in the behavioural effects observed in rodents after ethanol administration. This role\\u000a seems to be related to the ability of cerebral catalase to metabolise ethanol to acetaldehyde using H2O2 as a co-substrate. On the other hand, it has been shown that normobaric

  19. Upregulation of Leukotriene Receptors in Gastric Cancer

    PubMed Central

    Venerito, Marino; Kuester, Doerthe; Harms, Caroline; Schubert, Daniel; Wex, Thomas; Malfertheiner, Peter

    2011-01-01

    Background Leukotrienes (LT) mediate allergic and inflammatory processes. Previously, we identified significant changes in the expression pattern of LT receptors in the gastric mucosa after eradication of Helicobacter pylori infection. The aim of the present study was to evaluate the expression of 5-lipoxygenase (5-LOX) and LT receptors in gastric cancer (GC). Methods The expression of 5-LOX and receptors for LTB4 (BLT-1, BLT-2) and cysteinyl-LT (CysLT-1, CysLT-2) were analyzed by immunohistochemistry (IHC) in GC samples of 35 consecutive patients who underwent gastrectomy and in 29 tumor-free tissue specimens from gastric mucosa. Results Male-to-female ratio was 24:11. The median age was 70 years (range 34–91). Twenty-two patients had GC of intestinal, six of diffuse, six of mixed and one of undifferentiated type. The IHC analysis showed a nearly ubiquitous expression of studied proteins in GC (88–97%) and in tumor-free specimens as well (89–100%). An increase in the immunoreactive score of both BLT receptors and CysLT-1 was observed in GC compared to tumor-free gastric mucosa (p < 0.001 for BLT-1; p < 0.01 for BLT-2 and CysLT-1, Mann-Whitney U-test). No differences in the IHC expression of 5-LOX and CsyLT-2 were observed between GC and tumor-free mucosa. The expression of BLT-2, CysLT-1 and CysLT-2 was increased in GC of intestinal type when compared to the diffuse type (p < 0.05; Mann-Whitney U-test). Conclusions LTB4 receptors and CysLT-1 are up-regulated in GC tissue implying a role in gastric carcinogenesis. PMID:24212950

  20. Toward "stable-on-the-table" enzymes: improving key properties of catalase by covalent conjugation with poly(acrylic acid).

    PubMed

    Riccardi, Caterina M; Cole, Kyle S; Benson, Kyle R; Ward, Jessamyn R; Bassett, Kayla M; Zhang, Yiren; Zore, Omkar V; Stromer, Bobbi; Kasi, Rajeswari M; Kumar, Challa V

    2014-08-20

    Several key properties of catalase such as thermal stability, resistance to protease degradation, and resistance to ascorbate inhibition were improved, while retaining its structure and activity, by conjugation to poly(acrylic acid) (PAA, Mw 8000) via carbodiimide chemistry where the amine groups on the protein are appended to the carboxyl groups of the polymer. Catalase conjugation was examined at three different pH values (pH 5.0, 6.0, and 7.0) and at three distinct mole ratios (1:100, 1:500, and 1:1000) of catalase to PAA at each reaction pH. The corresponding products are labeled as Cat-PAA(x)-y, where x is the protein to polymer mole ratio and y is the pH used for the synthesis. The coupling reaction consumed about 60-70% of the primary amines on the catalase; all samples were completely water-soluble and formed nanogels, as evidenced by gel electrophoresis and electron microscopy. The UV circular dichroism (CD) spectra indicated substantial retention of protein secondary structure for all samples, which increased to 100% with increasing pH of the synthesis and polymer mole fraction. Soret CD bands of all samples indicated loss of ?50% of band intensities, independent of the reaction pH. Catalytic activities of the conjugates increased with increasing synthesis pH, where 55-80% and 90-100% activity was retained for all samples synthesized at pH 5.0 and pH 7.0, respectively, and the Km or Vmax values of Cat-PAA(100)-7 did not differ significantly from those of the free enzyme. All conjugates synthesized at pH 7.0 were thermally stable even when heated to ?85-90 °C, while native catalase denatured between 55 and 65 °C. All conjugates retained 40-90% of their original activities even after storing for 10 weeks at 8 °C, while unmodified catalase lost all of its activity within 2 weeks, under similar storage conditions. Interestingly, PAA surrounding catalase limited access to the enzyme from large molecules like proteases and significantly increased resistance to trypsin digestion compared to unmodified catalase. Similarly, negatively charged PAA surrounding the catalase in these conjugates protected the enzyme against inhibition by negatively charged inhibitors such as ascorbate. While Cat-PAA(100)-7 did not show any inhibition by ascorbate in the presence of 270 ?M ascorbate, unmodified catalase lost ?70% of its activity under similar conditions. This simple, facile, and rational methodology produced thermostable, storable catalase that is also protected from protease digestion and ascorbate inhibition and most likely prevented the dissociation of the multimer. Using synthetic polymers to protect and improve enzyme properties could be an attractive approach for making "Stable-on-the-Table" enzymes, as a viable alternative to protein engineering. PMID:25046001

  1. Spectroscopic investigations on the interaction between carbon nanotubes and catalase on molecular level.

    PubMed

    Guan, Jin; Dai, Jingping; Zhao, Xingchen; Liu, Chunhua; Gao, Canzhu; Liu, Rutao

    2014-05-01

    The interactions between well-dispersed multiwalled carbon nanotubes (MWCNTs) and catalase (CAT) were investigated. The activity of CAT was inhibited with the addition of MWCNTs. After deducting the inner filter effect, the fluorescence spectra revealed that the tryptophan (Trp) residues were exposed and the fluorescence intensities of CAT increased with the increase in the MWCNTs concentration. At the same time, the environment of the Trp residues became more hydrophobic. The results of UV-vis absorption spectroscopy and CD spectra indicated that the secondary structure of CAT had been changed, and the amino acid residues were located in a more hydrophobic environment. Meanwhile, the UV-vis spectra indicated that the conformation of the heme porphyrin rings was changed. The microenvironment of CAT activity sites may be interfered by MWCNTs. This research showed that MWCNTs could not only contribute to the conformational changes of protein but also change the enzyme function. PMID:24616245

  2. Molecular interaction of 2-mercaptobenzimidazole with catalase reveals a potentially toxic mechanism of the inhibitor.

    PubMed

    Teng, Yue; Zou, Luyi; Huang, Ming; Zong, Wansong

    2014-12-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment possesses a potential risk to human health. In this work, the toxic interaction of MBI with the important antioxidant enzyme catalase (CAT) was investigated using spectroscopic and molecular docking methods under physiological conditions. MBI can spontaneously bind with CAT with one binding site through hydrogen bonds and van der Waals forces to form MBI-CAT complex. The molecular docking study revealed that MBI bound into the CAT interface of chains B and C, which led to some conformational and microenvironmental changes of CAT and further resulted in the inhibition of CAT activity. This present study provides direct evidence at a molecular level to show that exposure to MBI could induce changes in the structure and function of the enzyme CAT. PMID:25463673

  3. Lack of effect of deferoxamine, dimethyl sulfoxide, and catalase on monocrotaline pyrrole pulmonary injury

    SciTech Connect

    Bruner, L.H.; Johnson, K.; Carpenter, L.J.; Roth, R.A.

    1987-01-01

    Monocrotaline pyrrole (MCTP) is a reactive metabolite of the pyrrolizidine alkaloid monocrotaline. MCTP given intravenously to rats causes pulmonary hypertension and right ventricular hypertrophy. Lesions in lungs after MCTP treatment contain macrophages and neutrophils, which may contribute to the damage by generation of reactive oxygen metabolites. Rats were treated with MCTP and agents known to protect against oxygen radical-mediated damage in acute models of neutrophil-dependent lung injury. Rats received MCTP and deferoxamine mesylate (DF), dimethyl sulfoxide (DMSO), or polyethylene glycol-coupled catalase (PEG-CAT). MCTP/vehicle-treated controls developed lung injury manifested as increased lung weight, release of lactate dehydrogenase into the airway, and sequestration of SVI-labeled bovine serum albumin in the lungs. Cotreatment of rats with DF, DMSO, or PEG-CAT did not protect against the injury due to MCTP. These results suggest that toxic oxygen metabolites do not play an important role in the pathogenesis of MCTP-induced pulmonary injury.

  4. Novel Synthetic SOD/Catalase Mimetics Can Mitigate Capillary Endothelial Cell Apoptosis Caused by Ionizing Radiation

    PubMed Central

    Vorotnikova, Ekaterina; Rosenthal, Rosalind A.; Tries, Mark; Doctrow, Susan R.; Braunhut, Susan J.

    2015-01-01

    Numerous in vitro and in vivo studies have shown that the endothelial cells of the microvasculature of the lung and kidney are damaged by exposure to ionizing radiation, and this sustained endothelial cell injury is involved in the early and late radiation effects observed in these tissues. It is well accepted that ionizing radiation causes the generation of reactive oxygen species during exposure that results in damage to DNA and cellular organelles. It is more controversial, however, whether additional biochemical events or long-lived radicals occur and persist postirradiation that amplify and initiate new forms of cellular damage. Two families of Eukarion (EUK) compounds have been synthesized that possess superoxide dismutase (SOD), catalase and peroxidase activities. The Mn porphyrins are available orally whereas the salen Mn complexes are administered by injection. In the present study we have examined the ability of these SOD/catalase mimetics to prevent apoptosis of endothelial cells when administered 1 h postirradiation (mitigation). A range of salen Mn complex (EUK-189 and EUK-207) and Mn porphyrins (EUK-418, -423, -425, -450, -451, -452, -453) were used to treat endothelial cells 1 h after the cells received 2–20 Gy ionizing radiation in vitro. Two lead compounds, EUK-207 at a dose of 30 ?M and EUK-451 at a dose of 10 ?M, exhibited low toxicity and mitigated radiation-induced apoptosis. Future animal studies will test whether these compounds protect when administered after radiation exposure as would be done after a radiological accident or a terrorism event. PMID:20518654

  5. Evidence of catalase mimetic activity in ce(3+)/ce(4+) doped bioactive glasses.

    PubMed

    Nicolini, Valentina; Gambuzzi, Elisa; Malavasi, Gianluca; Menabue, Ledi; Menziani, Maria Cristina; Lusvardi, Gigliola; Pedone, Alfonso; Benedetti, Francesco; Luches, Paola; D'Addato, Sergio; Valeri, Sergio

    2015-03-12

    The ability of Ce-containing bioactive glasses to inhibit oxidative stress in terms of reduction of hydrogen peroxide, by mimicking the catalase enzyme activity is demonstrated here for the first time. The antioxidant properties of three bioactive glasses containing an increasing amount of CeO2 have been evaluated by following the degradation of hydrogen peroxide with time after immersion in H2O2 aqueous solutions with different concentration. XPS and UV-vis measurements allowed us to determine the Ce(3+)/Ce(4+) ratio in the bulk and on the glass surface, and to correlate it with the ability of the samples to show catalase mimetic activity. Interestingly, we have found that the bioactive glass with composition 23.2Na2O-25.7CaO-43.4SiO2-2.4P2O5-5.3CeO2 immersed in 0.1 M H2O2 aqueous solution is able to degrade 90% of it in 1 week. The reduction in bioactivity of the glasses with increasing CeO2 content is here rationalized in terms of a lower amount of phosphate groups available for the hydroxyapatite layer formation, after binding with cerium ions. In fact, classical molecular dynamics simulations revealed that the addition of CeO2 leads to the formation of cerium phosphate rich regions. The formation of an insoluble CePO4 crystalline phase is also observed by XRD analysis after thermal treatment of the glass samples. PMID:25710332

  6. Associations of catalase gene polymorphisms with bone mineral density and bone turnover markers in postmenopausal women

    PubMed Central

    Oh, Bermseok; Kim, Shin?Yoon; Kim, Duk Jae; Lee, Jong Yong; Lee, Jong?Keuk; Kimm, Kuchan; Park, Byung Lae; Shin, Hyoung Doo; Kim, Tae?Ho; Park, Eui Kyun; Koh, Jung?Min; Kim, Ghi Su

    2007-01-01

    Background Oxidative stress has been recently suggested to play a part in the development of osteoporosis. Catalase is a major antioxidant enzyme that detoxifies hydrogen peroxide by converting it into water and oxygen, thereby preventing cellular injury by oxidative stress. Aims To examine the associations between the catalase gene (CAT) polymorphisms and bone mineral density (BMD) and bone turnover markers in postmenopausal Korean women. Methods All exons, their boundaries and the promoter region (approximately 1.5?kb) were directly sequenced in 24 individuals. Among 18 variants identified by a direct sequence method, four polymorphisms were selected and genotyped in all study participants (n?=?560). BMD at the lumbar spine and proximal femur was measured using dual?energy x ray absorptiometry. Serum osteocalcin concentrations and bone?specific alkaline phosphatase activity were determined by an immunoradiometric assay and an immunoassay, respectively. Results The mean (standard deviation) age of the participants was 59.4 (7.2)?years. Multivariate analysis showed an association of the +22348C?T polymorphism with BMD at the lumbar spine (p?=?0.01 in the dominant model) and at femur neck (p?=?0.05 in the dominant model), and with serum osteocalcin level (p?=?0.008 in the dominant model). Haplotype analyses showed that HT4 (?20T, +144C, +22348T, +33078A) was significantly associated with higher BMD at various sites (p<0.001–0.03) and with lower serum osteocalcin levels (p?=?0.01 in the codominant model). Conclusions These findings indicate that the +22348C?T polymorphism and HT4 of CAT may be useful genetic markers for bone metabolism. PMID:17209132

  7. Semenogelin I expression in myeloma cells can be upregulated pharmacologically.

    PubMed

    Zhang, Yana; Wang, Zhiqing; Zhang, Jian; Farmer, Benjamin; Lim, Seah H

    2008-12-01

    Semenogelin (SEMG) I is a Cancer-Testis (CT) antigen that we have found to be expressed in myeloma cells. In this study, we set out to determine whether the expression of SEMG I could be upregulated pharmacologically. We found that SEMG I expression in myeloma cells can be upregulated by 5-azacytidine, IL-4 and IL-6. The mechanisms of SEMG I gene upregulation by 5-azacytidine is unclear since there was no correlation between the methylation of the single CpG dinucleotide at position -11 and SEMG I expression. Both IL-4 and IL-6 appeared to enhance SEMG I expression through increasing its promoter function. PMID:18468680

  8. Effect of the Peroxisome Proliferator Ciprofibrate on Lipid Peroxidation and 8-Hydroxydeoxyguanosine Formation in Transgenic Mice with Elevated Hepatic Catalase Activity

    Microsoft Academic Search

    Vani Nilakantan; Brett T Spear; Howard P Glauert

    1998-01-01

    Peroxisome proliferators are a group of non-genotoxic hepatic carcinogens which have been proposed to act by increasing oxidative damage in the liver. To test this hypothesis, we have produced a transgenic mouse line that has elevated catalase activity specifically in the liver. In this study, we have examined if catalase overexpression influences the induction of lipid peroxidation or oxidative DNA

  9. Water-soluble and lipid-bound liver catalase activity in CC57BR mice with virus hemocytoblastosis — Reticulosis

    Microsoft Academic Search

    A. F. Konyukhov; N. P. Mazurenko

    1968-01-01

    A previous investigation [3] showed that the development of transplantable virus leukemia of mice is accompanied by marked suppression of activityofthewat er-soluble catalase (WSC)of the liver. In the same publication the reproduction of a similar effect in healthy mice by parenteral injection of extracts from tissues and organs of animals with the disease is described. Thermostable toxic substances contained in

  10. Arsenic trioxide induces apoptosis of p53 null osteosarcoma MG63 cells through the inhibition of catalase.

    PubMed

    Wang, Yang; Wei, Yudan; Zhang, Haiying; Shi, Yanfen; Li, Yulin; Li, Ronggui

    2012-06-01

    This study is aimed at investigating the effect of arsenic trioxide (ATO) on p53 null human osteosarcoma MG63 cells and the mechanisms underlying the effect. Apoptotic cells were detected by flow cytometry with Annexin-V-FITC/PI dual staining. Intracellular ROS was measured by flow cytometry using a cell-based ROS assay kit. Catalase activity and mRNAs were analyzed by ELISA and real-time qRT-PCR, respectively. Apoptosis and intracellular ROS of MG63 cells increased in a dose-dependent manner following arsenic treatments. Both were prevented by the presence of the anti-oxidative reagent N-acetyl-L: -cysteine (NAC) or catalase (CAT). Furthermore, the activity and mRNA of catalase were decreased strikingly following arsenic exposure. The present study indicates that p53 null osteosarcoma MG63 cells are susceptible to the ATO; the inhibition of catalase and the resulted intracellular ROS accumulation are an important molecular mechanism under which ATO induces apoptosis of p53-deficient osteosarcoma cells. PMID:21308489

  11. Effects of estrogens and androgens on erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase activities during the menstrual cycle

    Microsoft Academic Search

    C Massafra; D Gioia; C De Felice; E Picciolini; V De Leo; M Bonifazi; A Bernabei

    2000-01-01

    The effects of physiological changes in estrogens and androgens on the erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase enzyme activities during the menstrual cycle were investigated in healthy eumenorrheic women. Blood samples were taken on alternate days from twelve normally cyclic women (age range: 20 to 27 years; mean age: 24·1 years) from the first day of one menstrual

  12. PprA: A protein implicated in radioresistance of Deinococcus radiodurans stimulates catalase activity in Escherichia coli.

    PubMed

    Kota, Swathi; Misra, Hari S

    2006-10-01

    PprA: a pleiotropic protein promoting DNA repair, role in radiation resistance of Deinococcus radiodurans was demonstrated. In this study, the effect of radiation and oxidative stress on transgenic Escherichia coli expressing pprA has been studied. The pprA gene from D. radiodurans KR1 was cloned and expressed in E. coli. Transgenic E. coli cells expressing PprA showed twofold to threefold higher tolerance to hydrogen peroxide as compared to control. The 2.8-fold in vivo stimulation of catalase activity largely contributed by KatE was observed as compared to nonrecombinant control. Furthermore, the purified PprA could stimulate the E. coli catalase activity by 1.7-fold in solution. The effect of PprA on catalase activity observed both in vivo and in vitro was reverted to normal levels in the presence of PprA antibodies. The results suggest that enhanced oxidative stress tolerance in E. coli expressing PprA was due to the PprA stimulation of catalase activity, perhaps through the interaction of these proteins. PMID:16586106

  13. Thermo-alkali-stable catalases from newly isolated Bacillus sp. for the treatment and recycling of textile bleaching effluents.

    PubMed

    Paar, A; Costa, S; Tzanov, T; Gudelj, M; Robra, K H; Cavaco-Paulo, A; Gübitz, G M

    2001-08-23

    Three thermoalkaliphilic bacteria, which were grown at pH 9.3-10 and 60-65 degrees C were isolated out of a textile wastewater drain. The unknown micro-organisms were identified as thermoalkaliphilic Bacillus sp. Growth conditions were studied and catalase activities and stabilities compared. Catalases from Bacillus SF showed high stabilities at 60 degrees C and pH 9 (t1/2=38 h) and thus this strain was chosen for further investigations, such as electron microscopy, immobilization of catalase and hydrogen peroxide degradation studies. Degradation of hydrogen peroxide with an immobilized catalase from Bacillus SF enabled the reuse of the water for the dyeing process. In contrast, application of the free enzyme for treatment of bleaching effluents, caused interaction between the denaturated protein and the dye, resulting in reduced dye uptake, and a higher color difference of 1.3DeltaE* of dyed fabrics compared to 0.9DeltaE* when using the immobilized enzyme. PMID:11500208

  14. Original Contribution The induction of human superoxide dismutase and catalase in vivo: A fundamentally new approach to antioxidant therapy

    Microsoft Academic Search

    Sally K. Nelson; Swapan K. Bose; Gary K. Grunwald; Paul Myhill; Joe M. McCord

    A composition consisting of extracts of five widely studied medicinal plants (Protandim) was administered to healthy human subjects ranging in age from 20 to 78 years. Individual ingredients were selected on the basis of published findings of induction of superoxide dismutase (SOD) and\\/or catalase in rodents in vivo, combined with evidence of decreasing lipid peroxidation. Each ingredient was present at

  15. High-level resistance to oxidative stress in Lactococcus lactis conferred by Bacillus subtilis catalase KatE.

    PubMed

    Rochat, T; Miyoshi, A; Gratadoux, J J; Duwat, P; Sourice, S; Azevedo, V; Langella, P

    2005-09-01

    Lactococcus lactis, a lactic acid bacterium widely used for food fermentations, is often exposed to damaging stress conditions. In particular, oxidative stress leads to DNA, protein and membrane damages that can be lethal. As L. lactis has no catalase, the impact of production of the Bacillus subtilis haem catalase KatE on its oxidative stress resistance was tested. This cytoplasmic catalase was engineered for extracellular expression in L. lactis with an optimization strategy based on fusion to the nisin-inducible promoter and a lactococcal signal peptide (SP(Usp45)). The production of KatE by L. lactis conferred an 800-fold increase in survival after 1 h exposure to 4 mM hydrogen peroxide, and a 160-fold greater survival in long-term (3 days) survival of aerated cultures in a cydA mutant, which is unable to respire. The presence of KatE protected DNA from oxidative damage and limited its degradation after long-term aeration in a cydA/recA mutant, defective in DNA repair. L. lactis is thus able to produce active catalase that can provide efficient antioxidant activity. PMID:16151211

  16. Age-related changes in catalase and peroxidase activities in the excised leaves of Eleusine coracana Gaertin. cv PR 202 during senescence.

    PubMed

    Kumar, K B; Khan, P A

    1983-01-01

    Changes in the activities of the enzymes catalase and peroxidase were studied in the excised leaves of ragi (Eleusine coracana Gaertn. cv PR 202) plants belonging to different ages. Catalase exhibited a positive and peroxidase a negative correlation with the changes in chlorophyll. Catalase and peroxidase were negatively correlated with each other. Peroxidase exhibited an age-related drift in its activity. Kinetin could maintain the levels of chlorophyll and catalase, and also caused an increase in peroxidase activity. Both indoleacetic acid and gibberellic acid had no effect on the changes of chlorophyll but increased peroxidase activity. Catalase levels were maintained by indoleacetic acid but gibberellic acid had no effect on this enzyme. PMID:6321215

  17. Catalase abrogates ?-lapachone-induced PARP1 hyperactivation-directed programmed necrosis in NQO1-positive breast cancers

    PubMed Central

    Bey, Erik A.; Reinicke, Kathryn E.; Srougi, Melissa C.; Varnes, Marie; Anderson, Vernon; Pink, John J.; Li, Long Shan; Patel, Malina; Cao, Lifen; Moore, Zachary; Rommel, Amy; Boatman, Michael; Lewis, Cheryl; Euhus, David M.; Bornmann, William G.; Buchsbaum, Donald J.; Spitz, Douglas R.; Gao, Jinming; Boothman, David A.

    2013-01-01

    Improving patient outcome by personalized therapy involves a thorough understanding of an agent’s mechanism of action. ?-Lapachone (clinical forms, Arq501/Arq761) has been developed to exploit dramatic cancer-specific elevations in the phase II detoxifying enzyme, NAD(P)H:quinone oxidoreductase (NQO1). NQO1 is dramatically elevated in solid cancers, including primary and metastatic (e.g., triple-negative (ER-, PR-, Her2/Neu-)) breast cancers. To define cellular factors that influence the efficacy of ?-lapachone using knowledge of its mechanism of action, we confirmed that NQO1 was required for lethality and mediated a futile redox cycle where ~120 moles of superoxide were formed per mole of ?-lapachone in 5 min. ?-Lapachone induced reactive oxygen species (ROS), stimulated DNA single strand break-dependent PARP1 hyperactivation, caused dramatic loss of essential nucleotides (NAD+/ATP) and elicited programmed necrosis in breast cancer cells. While PARP1 hyperactivation and NQO1 expression were major determinants of ?-lapachone-induced lethality, alterations in catalase expression, including treatment with exogenous enzyme, caused marked cytoprotection. Thus, catalase is an important resistance factor, and highlights H2O2 as an obligate ROS for cell death from this agent. Exogenous superoxide dismutase (SOD) enhanced catalase-induced cytoprotection. ?-Lapachone-induced cell death included AIF translocation from mitochondria to nuclei, TUNEL+ staining, atypical PARP1 cleavage, and GAPDH S-nitrosylation, which were abrogated by catalase. We predict that the ratio of NQO1:catalase activities in breast cancer versus associated normal tissue are likely to be the major determinants affecting the therapeutic window of ?-lapachone and other NQO1 bioactivatable drugs. PMID:23883585

  18. Isolation of a Novel Peroxisomal Catalase Gene from Sugarcane, Which Is Responsive to Biotic and Abiotic Stresses

    PubMed Central

    Ling, Hui; Chen, Shanshan; Wang, Shanshan; Xu, Liping; Allan, Andrew C.; Que, Youxiong

    2014-01-01

    Catalase is an iron porphyrin enzyme, which serves as an efficient scavenger of reactive oxygen species (ROS) to avoid oxidative damage. In sugarcane, the enzymatic activity of catalase in a variety (Yacheng05–179) resistant to the smut pathogen Sporisorium scitamineum was always higher than that of the susceptible variety (Liucheng03–182), suggesting that catalase activity may have a positive correlation with smut resistance in sugarcane. To understand the function of catalase at the molecular level, a cDNA sequence of ScCAT1 (GenBank Accession No. KF664183), was isolated from sugarcane infected by S. scitamineum. ScCAT1 was predicted to encode 492 amino acid residues, and its deduced amino acid sequence shared a high degree of homology with other plant catalases. Enhanced growth of ScCAT1 in recombinant Escherichia coli Rosetta cells under the stresses of CuCl2, CdCl2 and NaCl indicated its high tolerance. Q-PCR results showed that ScCAT1 was expressed at relatively high levels in the bud, whereas expression was moderate in stem epidermis and stem pith. Different kinds of stresses, including S. scitamineum challenge, plant hormones (SA, MeJA and ABA) treatments, oxidative (H2O2) stress, heavy metal (CuCl2) and hyper-osmotic (PEG and NaCl) stresses, triggered a significant induction of ScCAT1. The ScCAT1 protein appeared to localize in plasma membrane and cytoplasm. Furthermore, histochemical assays using DAB and trypan blue staining, as well as conductivity measurement, indicated that ScCAT1 may confer the sugarcane immunity. In conclusion, the positive response of ScCAT1 to biotic and abiotic stresses suggests that ScCAT1 is involved in protection of sugarcane against reactive oxidant-related environmental stimuli. PMID:24392135

  19. Isolation of a novel peroxisomal catalase gene from sugarcane, which is responsive to biotic and abiotic stresses.

    PubMed

    Su, Yachun; Guo, Jinlong; Ling, Hui; Chen, Shanshan; Wang, Shanshan; Xu, Liping; Allan, Andrew C; Que, Youxiong

    2014-01-01

    Catalase is an iron porphyrin enzyme, which serves as an efficient scavenger of reactive oxygen species (ROS) to avoid oxidative damage. In sugarcane, the enzymatic activity of catalase in a variety (Yacheng05-179) resistant to the smut pathogen Sporisorium scitamineum was always higher than that of the susceptible variety (Liucheng03-182), suggesting that catalase activity may have a positive correlation with smut resistance in sugarcane. To understand the function of catalase at the molecular level, a cDNA sequence of ScCAT1 (GenBank Accession No. KF664183), was isolated from sugarcane infected by S. scitamineum. ScCAT1 was predicted to encode 492 amino acid residues, and its deduced amino acid sequence shared a high degree of homology with other plant catalases. Enhanced growth of ScCAT1 in recombinant Escherichia coli Rosetta cells under the stresses of CuCl2, CdCl2 and NaCl indicated its high tolerance. Q-PCR results showed that ScCAT1 was expressed at relatively high levels in the bud, whereas expression was moderate in stem epidermis and stem pith. Different kinds of stresses, including S. scitamineum challenge, plant hormones (SA, MeJA and ABA) treatments, oxidative (H2O2) stress, heavy metal (CuCl2) and hyper-osmotic (PEG and NaCl) stresses, triggered a significant induction of ScCAT1. The ScCAT1 protein appeared to localize in plasma membrane and cytoplasm. Furthermore, histochemical assays using DAB and trypan blue staining, as well as conductivity measurement, indicated that ScCAT1 may confer the sugarcane immunity. In conclusion, the positive response of ScCAT1 to biotic and abiotic stresses suggests that ScCAT1 is involved in protection of sugarcane against reactive oxidant-related environmental stimuli. PMID:24392135

  20. Improving of catalase stability properties by encapsulation in alginate/Fe3O4 magnetic composite beads for enzymatic removal of H2O2.

    PubMed

    Do?aç, Yasemin Ispirli; Çinar, Mürvet; Teke, Mustafa

    2015-01-01

    The aim of this study was enhancing of stability properties of catalase enzyme by encapsulation in alginate/nanomagnetic beads. Amounts of carrier (10-100 mg) and enzyme concentrations (0.25-1.5 mg/mL) were analyzed to optimize immobilization conditions. Also, the optimum temperature (25-50°C), optimum pH (3.0-8.0), kinetic parameters, thermal stability (20-70°C), pH stability (4.0-9.0) operational stability (0-390 min), and reusability were investigated for characterization of the immobilized catalase system. The optimum pH levels of both free and immobilized catalase were 7.0. At the thermal stability studies, the magnetic catalase beads protected 90% activity, while free catalase maintained only 10% activity at 70°C. The thermal profile of magnetic catalase beads was spread over a large area. Similarly, this system indicated the improving of the pH stability. The reusability, which is especially important for industrial applications, was also determined. Thus, the activity analysis was done 50 times in succession. Catalase encapsulated magnetic alginate beads protected 83% activity after 50 cycles. PMID:24679144

  1. Antioxidant pathways are up-regulated during biological nitrogen fixation to prevent ROS-induced nitrogenase inhibition in Gluconacetobacter diazotrophicus

    PubMed Central

    Oliveira, Jose Henrique M.; Nogueira, Eduardo M.; Guedes, Helma V.; Oliveira, Pedro L.; Câmara, Fernando; Baldani, Jose I.; Martins, Orlando B.

    2010-01-01

    Gluconacetobacter diazotrophicus, an endophyte isolated from sugarcane, is a strict aerobe that fixates N2. This process is catalyzed by nitrogenase and requires copious amounts of ATP. Nitrogenase activity is extremely sensitive to inhibition by oxygen and reactive oxygen species (ROS). However, the elevated oxidative metabolic rates required to sustain biological nitrogen fixation (BNF) may favor an increased production of ROS. Here, we explored this paradox and observed that ROS levels are, in fact, decreased in nitrogen-fixing cells due to the up-regulation of transcript levels of six ROS-detoxifying genes. A cluster analyses based on common expression patterns revealed the existence of a stable cluster with 99.8% similarity made up of the genes encoding the ?-subunit of nitrogenase Mo–Fe protein (nifD), superoxide dismutase (sodA) and catalase type E (katE). Finally, nitrogenase activity was inhibited in a dose-dependent manner by paraquat, a redox cycler that increases cellular ROS levels. Our data revealed that ROS can strongly inhibit nitrogenase activity, and G. diazotrophicus alters its redox metabolism during BNF by increasing antioxidant transcript levels resulting in a lower ROS generation. We suggest that careful controlled ROS production during this critical phase is an adaptive mechanism to allow nitrogen fixation. PMID:20697694

  2. Up-regulated expression of AOS-LOXa and increased eicosanoid synthesis in response to coral wounding.

    PubMed

    Lõhelaid, Helike; Teder, Tarvi; Tõldsepp, Kadri; Ekins, Merrick; Samel, Nigulas

    2014-01-01

    In octocorals, a catalase-like allene oxide synthase (AOS) and an 8R-lipoxygenase (LOX) gene are fused together encoding for a single AOS-LOX fusion protein. Although the AOS-LOX pathway is central to the arachidonate metabolism in corals, its biological function in coral homeostasis is unclear. Using an acute incision wound model in the soft coral Capnella imbricata, we here test whether LOX pathway, similar to its role in plants, can contribute to the coral damage response and regeneration. Analysis of metabolites formed from exogenous arachidonate before and after fixed time intervals following wounding indicated a significant increase in AOS-LOX activity in response to mechanical injury. Two AOS-LOX isoforms, AOS-LOXa and AOS-LOXb, were cloned and expressed in bacterial expression system as active fusion proteins. Transcription levels of corresponding genes were measured in normal and stressed coral by qPCR. After wounding, AOS-LOXa was markedly up-regulated in both, the tissue adjacent to the incision and distal parts of a coral colony (with the maximum reached at 1 h and 6 h post wounding, respectively), while AOS-LOXb was stable. According to mRNA expression analysis, combined with detection of eicosanoid product formation for the first time, the AOS-LOX was identified as an early stress response gene which is induced by mechanical injury in coral. PMID:24551239

  3. Gestational exposure to BDE-99 produces toxicity through upregulation of CYP isoforms and ROS production in the fetal rat liver.

    PubMed

    Blanco, Jordi; Mulero, Miquel; Domingo, José L; Sánchez, Domènec J

    2012-05-01

    On gestation day (GD) 6 to GD 19, pregnant Sprague Dawley rats were orally exposed to 0, 0.5, 1, and 2 mg/kg/day to one of the most prevalent polybrominated diphenyl ethers congeners found in humans, 2,2',4,4',5-pentaBDE (BDE-99). All dams were euthanized on GD 20, and live fetuses were evaluated for sex, body weight, and external, internal, and skeletal malformations and developmental variations. The liver from one fetus of each litter was excised for the evaluation of oxidative stress markers and the messenger RNA expression of multiple cytochrome P450 (CYP) isoforms. Exposure to BDE-99 during the gestational period produced delayed ossification, slight hypertrophy of the heart, and enlargement of the liver in fetuses. A transplacental effect of BDE-99, evidenced by the activation of nuclear hormones receptors that induce the upregulation of CYP1A1, CYP1A2, CYP2B1, and CYP3A2 isoforms, was also found in fetal liver. These isoforms are correlated with the activity level of the enzyme catalase and the levels of thiobarbituric acid reactive substances. However, teratogenic effects from BDE-99 exposure were not observed. Clear signs of embryo/fetal toxicity, due to a possible hormonal disruption, were evidenced by a large increase in the CYP system and the production of reactive oxygen species in fetal liver. PMID:22331496

  4. Ultracentrifugal crystallization of proteins: transport-kinetic modelling, and experimental behavior of catalase

    NASA Astrophysics Data System (ADS)

    Lenhoff, A. M.; Pjura, P. E.; Dilmore, J. G.; Godlewski, T. S.

    1997-09-01

    Although ultracentrifugal crystallization (UC) of proteins has been demonstrated previously and its main advantages established, a clear quantitative understanding of the phenomena involved has not been presented. This issue is addressed here by development of a model accounting for the key transport (sedimentation, diffusion) and kinetic (nucleation, growth) effects in UC. Numerical solution of the governing equations shows how the protein concentration profile changes with time, and how it interacts with the crystallization kinetic phenomena near the bottom of the tube to give rise to protein crystals. It is shown that the centrifugal speed and the initial protein concentration represent the most convenient parameters to use in manipulating crystallization behavior. Some of the predicted features of UC behavior were explored experimentally using bovine liver catalase. Crystal size increased and optical activity improved as the initial protein concentration was reduced. Crystallization was very robust to the presence of appreciable quantities of impurities. UC appears to be an underused route to protein crystallization, and the availability of a quantitative model may aid in its application to novel protein systems.

  5. Catalase prevents maternal diabetes-induced perinatal programming via the Nrf2-HO-1 defense system.

    PubMed

    Chang, Shiao-Ying; Chen, Yun-Wen; Zhao, Xin-Ping; Chenier, Isabelle; Tran, Stella; Sauvé, Alexandre; Ingelfinger, Julie R; Zhang, Shao-Ling

    2012-10-01

    We investigated whether overexpression of catalase (CAT) in renal proximal tubular cells (RPTCs) could prevent the programming of hypertension and kidney disease in the offspring of dams with maternal diabetes. Male offspring of nondiabetic and diabetic dams from two transgenic (Tg) lines (Hoxb7-green fluorescent protein [GFP]-Tg [controls] and Hoxb7/CAT-GFP-Tg, which overexpress CAT in RPTCs) were studied from the prenatal period into adulthood. Nephrogenesis, systolic blood pressure, renal hyperfiltration, kidney injury, and reactive oxygen species (ROS) generation were assessed. Gene expression of transforming growth factor-?1 (TGF-?1), nuclear factor erythroid 2p45-related factor-2 (Nrf2), and heme oxygenase-1 (HO-1) was tested in both in vitro and in vivo studies. Renal dysmorphogenesis was observed in offspring of Hoxb7-GFP-Tg dams with severe maternal diabetes; the affected male offspring displayed higher renal ROS generation and developed hypertension and renal hyperfiltration as well as renal injury with heightened TGF-?1 expression in adulthood. These changes were ameliorated in male offspring of diabetic Hoxb7/CAT-GFP-Tg dams via the Nrf2-HO-1 defense system. CAT promoted Nrf2 nuclear translocation and HO-1 gene expression, seen in both in vitro and in vivo studies. In conclusion, CAT overexpression in the RPTCs ameliorated maternal diabetes-induced perinatal programming, mediated, at least in part, by triggering the Nrf2-HO-1 defense system. PMID:22733796

  6. Effects of humic acid-metal complexes on hepatic carnitine palmitoyltransferase, carnitine acetyltransferase and catalase activities

    SciTech Connect

    Fungjou Lu; Youngshin Chen (National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Biochemistry); Tienshang Huang (National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Medicine)

    1994-03-01

    A significant increase in activities of hepatic carnitine palmitoyltransferase and carnitine acetyltransferase was observed in male Balb/c mice intraperitoneally injected for 40 d with 0.125 mg/0.1 ml/d humic acid-metal complexes. Among these complexes, the humic acid-As complex was relatively effective, whereas humic acid-25 metal complex was more effective, and humic acid-26 metal complex was most effective. However, humic acid or metal mixtures, or metal such as As alone, was not effective. Humic acid-metal complexes also significantly decreased hepatic catalase activity. A marked decrease of 60-kDa polypeptide in liver cytoplasm was also observed on SDS-polyacrylamide gel electrophoresis after the mice had been injected with the complexes. Morphological analysis of a histopathological biopsy of such treated mice revealed several changes in hepatocytes, including focal necrosis and cell infiltration, mild fatty changes, reactive nuclei, and hypertrophy. Humic acid-metal complexes affect activities of metabolic enzymes of fatty acids, and this results in accumulation of hydrogen peroxide and increase of the lipid peroxidation. The products of lipid peroxidation may be responsible for liver damage and possible carcinogenesis. Previous studies in this laboratory had shown that humic acid-metal complex altered the coagulation system and that humic acid, per se, caused vasculopathy. Therefore, humic acid-metal complexes may be main causal factors of not only so-called blackfoot disease, but also the liver cancer prevailing on the southwestern coast of Taiwan.

  7. Sunflower cotyledons cope with copper stress by inducing catalase subunits less sensitive to oxidation.

    PubMed

    Pena, Liliana B; Azpilicueta, Claudia E; Gallego, Susana M

    2011-07-01

    Copper is an essential trace element for living organisms, in excess, can be toxic to the cell because of its capacity to generate reactive oxygen species (ROS). Catalase (CAT) catalyzes the dismutation of hydrogen peroxide into water and dioxygen and in plants it is located in peroxisomes and glyoxysomes. Different metals can induce changes in CAT activity, but the mechanism underlying its changes is unclear. After 4h of treatment with 5 and 10 ?M CuCl(2) a decrease in the specific CAT activity was detected in sunflower cotyledons of post-germinative heterotrophic seedlings. At 8h of treatment, 5 ?M Cu(2+) produced an induction of CAT activity while only a complete recovery to control values was observed for 10 ?M Cu(2+) treated seedlings. These activity variations were not related to the level of CAT protein expression, but they did correlate with the oxidative state of the CAT protein. This indicates that the mechanism of CAT inactivation by Cu(2+) involves oxidation of the protein structure. The level of the mRNA of CATA3 and CATA4 increased with the presence of the metal after 4h of exposure. These CAT genes code for the synthesis of CAT subunits less sensitive to oxidation, which would prevent the copper-induced oxidative inactivation of CAT. PMID:21696931

  8. Study on the interaction of catalase with pesticides by flow injection chemiluminescence and molecular docking.

    PubMed

    Tan, Xijuan; Wang, Zhuming; Chen, Donghua; Luo, Kai; Xiong, Xunyu; Song, Zhenghua

    2014-08-01

    The interaction mechanisms of catalase (CAT) with pesticides (including organophosphates: disulfoton, isofenphos-methyl, malathion, isocarbophos, dimethoate, dipterex, methamidophos and acephate; carbamates: carbaryl and methomyl; pyrethroids: fenvalerate and deltamethrin) were first investigated by flow injection (FI) chemiluminescence (CL) analysis and molecular docking. By homemade FI-CL model of lg[(I0-I)/I]=lgK+nlg[D], it was found that the binding processes of pesticides to CAT were spontaneous with the apparent binding constants K of 10(3)-10(5) L mol(-1) and the numbers of binding sites about 1.0. The binding abilities of pesticides to CAT followed the order: fenvalerate>deltamethrin>disulfoton>isofenphos-methyl>carbaryl>malathion>isocarbophos>dimethoate>dipterex>acephate>methomyl>methamidophos, which was generally similar to the order of determination sensitivity of pesticides. The thermodynamic parameters revealed that CAT bound with hydrophobic pesticides by hydrophobic interaction force, and with hydrophilic pesticides by hydrogen bond and van der Waals force. The pesticides to CAT molecular docking study showed that pesticides could enter into the cavity locating among the four subdomains of CAT, giving the specific amino acid residues and hydrogen bonds involved in CAT-pesticides interaction. It was also found that the lgK values of pesticides to CAT increased regularly with increasing lgP, Mr, MR and MV, suggesting that the hydrophobicity and steric property of pesticide played essential roles in its binding to CAT. PMID:24875908

  9. Bioaccumulation of fullerene (C60) and corresponding catalase elevation in Lumbriculus variegatus.

    PubMed

    Wang, Jiafan; Wages, Mike; Yu, Shuangying; Maul, Jonathan D; Mayer, Greg; Hope-Weeks, Louisa; Cobb, George P

    2014-05-01

    Fullerene (C(60)), with its unique physical properties and nanometer size, has been mass-produced for many applications in recent decades. The increased likelihood of direct release into the environment has raised interest in understanding both the environmental fate and corresponding biological effects of fullerenes to living organisms. Because few studies have emphasized fullerene uptake and resulting biochemical responses by living organisms, a toxicity screening test and a 28-d bioaccumulation test for Lumbriculus variegatus were performed. No mortality was observed in the range of 0.05?mg?C(60) /kg dry sediment to 11.33?mg?C(60) /kg dry sediment. A biota-sediment accumulation factor of micron-sized fullerene agglomerates (µ-C(60)) was 0.032?±?0.008 at day 28, which is relatively low compared with pyrene (1.62?±?0.22). Catalase (CAT) activity, an oxidative stress indicator, was elevated significantly on day 14 for L. variegatus exposed to µ-C(60) (p?=?0.034). This peak CAT activity corresponded to the highest body residues observed in the present study, 199?±?80?µg?C(60) /kg dry weight sediment. Additionally, smaller C(60) agglomerate size increased bioaccumulation potential in L. variegatus. The relationship between C(60) body residue and the increased CAT activity followed a linear regression. All results suggest that C(60) has a lower bioaccumulation potential than pyrene but a higher potential to induce oxidative stress in L. variegatus. PMID:24477927

  10. Influence of catalase gene silencing on the survivability of Sitobion avenae.

    PubMed

    Deng, Fei; Zhao, Zhangwu

    2014-05-01

    Reactive oxygen species (ROS), such as superoxide anions and hydrogen peroxide produced in cell metabolism, result in the disruption of cellular function and structure. Catalase (CAT), an enzyme which exists in almost all organisms including plants, invertebrates and vertebrates, acts in scavenging ROS. In this study, a sequence fragment encoding a CAT-like protein from wheat aphids (?Sitobion avenae) was cloned. Amino acid sequence alignment showed this CAT shared relatively high conservation with CAT sequences from other insects. We detected cat mRNA levels at nymphs of different stages and adults and results showed that cat expression in adults was significantly higher compared to juvenile stages. At the third instar stage, ingestion of dsCAT significantly knocked down CAT expression. Continuous feeding of dsCAT mixed in an artificial diet led to reduced survival rate and ecdysis index. This study indicates that cat, a potential target gene for management of insect pests, is important for maintaining the survival of ?S. avenae. PMID:24719312

  11. Predominant Catalase-negative Soil Bacteria. III. Agromyces, gen. n., Microorganisms Intermediary to Actinomyces and Nocardia1

    PubMed Central

    Gledhill, William E.; Casida, L. E.

    1969-01-01

    The occurrence of filamentous, branching, catalase-negative bacteria as a numerically predominant microflora of various soils was demonstrated by using a dilution frequency isolation procedure. The major characteristics of these organisms were those of the order Actinomycetales. However, they could not be placed in any of the present genera of this order and, therefore, a new genus, Agromyces, was proposed for these organisms. This genus includes catalase-negative, nutritionally-fastidious microorganisms whose cells produce a true branching mycelium that fragments into coccoid and diphtheroid forms. Also, they have an oxidative metabolism, are microaerophilic to aerobic, and contain neither diaminopimelic acid nor lysine as major constituents of the cell wall glycopeptide. The type species would be Agromyces ramosus, gen. n., sp. n. The possible importance of these organisms in clarifying certain phylogenetic relationships of the Actinomycetales is discussed. Images PMID:16349860

  12. Catalase activity, serum trace element and heavy metal concentrations, and vitamin A, D and E levels in pre-eclampsia.

    PubMed

    Kolusari, A; Kurdoglu, M; Yildizhan, R; Adali, E; Edirne, T; Cebi, A; Demir, H; Yoruk, I H

    2008-01-01

    Catalase (antioxidant enzyme) activity in erythrocytes and serum levels of trace elements (copper, iron, zinc), heavy metals (cadmium, cobalt) and vitamins A (retinol), D (cholecalciferol) and E (alpha-tocopherol) were measured in 145 subjects comprising 47 pre-eclamptic pregnant women (PE), 48 healthy pregnant women (HP) and 50 healthy non-pregnant controls (NP). Catalase, vitamins A, D and E and levels of cobalt were significantly lower in the PE group compared with the HP and NP groups, whereas levels of copper, iron and cadmium were significantly higher in the PE group than in the HP and NP groups. Levels of zinc were significantly lower in both the PE and HP groups compared with the NP group. This assessment of oxidant/antioxidant imbalance in pregnant women could be useful in the early identification of pre-eclampsia and antioxidant supplementation in the early weeks of gestation might be useful. PMID:19094444

  13. Catalase Influence in the Regulation of Coronary Resistance by Estrogen: Joint Action of Nitric Oxide and Hydrogen Peroxide

    PubMed Central

    Schenkel, Paulo C.; Fernandes, Rafael O.; Viegas, Vinícius U.; Campos, Cristina; Fernandes, Tânia R. G.; Araujo, Alex Sander da Rosa; Belló-Klein, Adriane

    2014-01-01

    We tested the influence of estrogen on coronary resistance regulation by modulating nitric oxide (NO) and hydrogen peroxide (H2O2) levels in female rats. For this, estrogen levels were manipulated and the hearts were immediately excised and perfused at a constant flow using a Langendorff's apparatus. Higher estrogen levels were associated with a lower coronary resistance, increased nitric oxide bioavailability, and higher levels of H2O2. When oxide nitric synthase blockade by L-NAME was performed, no significant changes were found in coronary resistance of ovariectomized rats. Additionally, we found an inverse association between NO levels and catalase activity. Taken together, our data suggest that, in the absence of estrogen influence and, therefore, reduced NO bioavailability, coronary resistance regulation seems to be more dependent on the H2O2 that is maintained at low levels by increased catalase activity. PMID:24669281

  14. Coexpression of bile salt hydrolase gene and catalase gene remarkably improves oxidative stress and bile salt resistance in Lactobacillus casei

    Microsoft Academic Search

    Guohong WangSheng; Sheng Yin; Haoran An; Shangwu Chen; Yanling Hao

    Lactic acid bacteria (LAB) encounter various types of stress during industrial processes and gastrointestinal transit. Catalase\\u000a (CAT) and bile salt hydrolase (BSH) can protect bacteria from oxidative stress or damage caused by bile salts by decomposing\\u000a hydrogen peroxide (H2O2) or deconjugating the bile salts, respectively. Lactobacillus\\u000a casei is a valuable probiotic strain and is often deficient in both CAT and

  15. A cytophotometric and electron-microscopical study on catalase activity in serial cryostat sections of rat liver

    Microsoft Academic Search

    Wilma M. Frederiks; Marjolijn Ankum; Klazina S. Bosch; Helena Vreeling-Sindelárová; Jacques P. M. Schellens; Cornelis J. F. Van Noorden

    1995-01-01

    Summary  The validity of the histochemical procedure for demonstrating catalase activity in cryostat sections of rat liver at the light-and electron-microscopical level was studied cytophotometrically. Incubations in the presence of 5 mm diaminobenzidine, 44 mm hydrogen peroxide and 2% polyvinyl alcohol performed on fixed cryostat sections resulted in the highest amounts of final reaction product precipitated in a fine granular form

  16. Covalent conjugation of tetrameric bovine liver catalase to liposome membranes for stabilization of the enzyme tertiary and quaternary structures

    Microsoft Academic Search

    Makoto Yoshimoto; Hideyuki Sakamoto; Hiroshi Shirakami

    2009-01-01

    Tetrameric bovine liver catalase (BLC) is unstable because of its dissociation into subunits at low enzyme concentrations and the conformational change of the subunits at high temperatures. In this work, for stabilization of BLC, the enzyme was covalently conjugated with liposome membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), cholesterol and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-glutaryl (NGPE). The NGPE, which was responsible for the BLC\\/membrane coupling, was

  17. The Action of the Carcinogen Ar(2-Fluorenyl)acetamide on Rat Liver Catalase and Arpiñasein Vivo

    Microsoft Academic Search

    H. R. GUTMANNj

    SUMMARY The oral administration of the carcinogens A^-(2-fluorenyl)acetamide and jV-hy- droxy-2-fluorenylacetamide to male rats for 6 weeks depressed the activity of liver cat- alase to the extent of 20-25 per cent, but had no effect on liver arginase. The catalase activity was restored by withdrawal of the compounds from the diet. The adminis tration of the noncarcinogenic metabolite Ar-(l-hydroxy-2-fluorenyl)acetamide had

  18. Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens

    Microsoft Academic Search

    Yongxiang Liu; Yuming Guo; Zhong Wang; We Nie

    2007-01-01

    The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3×3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens.

  19. A cytophotometric and electron-microscopical study on catalase activity in serial cryostat sections of rat liver

    Microsoft Academic Search

    Wilma M. Frederiks; Marjolijn Ankum; Klazina S. Bosch; Helena Vreeling-Sindelárová; Jacques P. M. Schellens; Cornelis J. F. Van Noorden

    1995-01-01

    Summary  The validity of the histochemical procedure for demonstrating catalase activity in cryostat sections of rat liver at the light-and\\u000a electron-microscopical level was studied cytophotometrically. Incubations in the presence of 5 mm diaminobenzidine, 44 mm hydrogen peroxide and 2% polyvinyl alcohol performed on fixed cryostat sections resulted in the highest amounts of final\\u000a reaction product precipitated in a fine granular form

  20. Therapeutic Effect of Recombinant Human Catalase on H1N1 Influenza-induced Pneumonia in Mice

    Microsoft Academic Search

    Xun-long Shi; Zhi-hui Shi; Hai Huang; Hong-guang Zhu; Pei Zhou; Dianwen Ju

    2010-01-01

    Reactive oxygen species (ROS) are believed to play a key role in the induction of lung damage caused by pneumonia and therapeutic\\u000a agents that could effectively scavenge ROS may prevent or reduce the deleterious effects of influenza-induced pneumonia. In\\u000a this study, we first demonstrated that human catalase could attenuate acute oxidative injury in lung tissues following influenza-induced\\u000a pneumonia. Mice were

  1. Anti-apoptotic proteins and catalase-dependent apoptosis resistance in nickel chloride-transformed human lung epithelial cells

    PubMed Central

    YANG, YU-XIU; LI, XIU-LING; WANG, LEI; HAN, SHUANG-YIN; ZHANG, YAN-RUI; PRATHEESHKUMAR, POYIL; WANG, XIN; LU, JIAN; YIN, YUAN-QIN; SUN, LI-JUAN; BUDHRAJA, AMIT; HITRON, ANDREW J.; DING, SONG-ZE

    2013-01-01

    Chronic exposure to nickel compounds is associated with increased incidence of certain types of human cancer, including lung and nasal cancers. Despite intensive investigation, the oncogenic processes remain poorly understood. Apoptosis resistance is a key feature for tumor cells to escape physiological surveillance and acquire growth advantage over normal cells. Although NiCl2 exposure induces transformation of human lung epithelial cells, little information is available with regard to its molecular mechanisms, it is also not clear if the transformed cells are apoptosis resistant and tumorigenic. We explored the apoptosis resistance properties of nickel chloride-transformed human lung epithelial cells and the underlying mechanisms. The results showed that transformed BEAS-2B human lung epithelial cells are resistant to NiCl2-induced apoptosis. They have increased Bcl-2, Bcl-xL and catalase protein levels over the passage matched non-transformed counterparts. The mechanisms of apoptosis resistance are mitochondria-mediated and caspase-dependent. Forced overexpression of Bcl-2, Bcl-xL and catalase proteins reduced NiCl2-induced cell death; siRNA-mediated knockdown of their expression sensitized the cells to nickel-induced apoptosis, suggesting that Bcl-2, Bcl-xl and catalase protein expression plays a critical role in apoptosis resistance. Akt also participates in this process, as its overexpression increases Bcl-xL protein expression levels and attenuates NiCl2-induced apoptosis. Furthermore, transformed cells are tumorigenic in a xenograft model. Together, these results demonstrate that nickel-transformed cells are apoptosis-resistant and tumorigenic. Increased expression of Bcl-2, Bcl-xL and catalase proteins are important mechanisms contributing to transformed cell oncogenic properties. PMID:23828460

  2. Response of peroxidase and catalase to acid rain stress during seed germination of rice, wheat, and rape

    Microsoft Academic Search

    Lihong Wang; Xiaohua Huang; Qing Zhou

    2008-01-01

    Seed germination of plants with various acid-resistance display different responses to acid rain. To understand the reason\\u000a why such differences occur, the effects of simulated acid rain (pH 2.5–5.0) on the activities of peroxidase (POD) and catalase\\u000a (CAT) during seed germination of rice (O. sativa), wheat (T. aestivum), and rape (B. chinensis var. oleifera) were investigated. Results indicated that the

  3. Molecular, technological and safety characterization of Gram-positive catalase-positive cocci from slightly fermented sausages

    Microsoft Academic Search

    B. Martín; M. Garriga; M. Hugas; S. Bover-Cid; M. T. Veciana-Nogués; T. Aymerich

    2006-01-01

    The population of Gram-positive catalase-positive cocci from slightly fermented sausages was characterized at species and strain level by molecular techniques and some technological and hygienic aspects were also considered. Staphylococcus xylosus was the predominant species (80.8%) followed by Staphylococcus warneri (8.3%), Staphylococcus epidermidis (5.8%) Staphylococcus carnosus (4.6%), and Kocuria varians (0.4%). Proteolytic activity was observed in 23% of the isolates.

  4. cDNA cloning and expression patterns of a peroxiredoxin, a catalase and a glutathione peroxidase from Haemonchus contortus

    Microsoft Academic Search

    N. H. Bagnall; A. C. Kotze

    2004-01-01

    The range of antioxidant enzyme systems available to Haemonchus contortus for detoxification of hydrogen peroxide was investigated using cDNA cloning of candidate genes. PCR with primers based on conserved amino acid regions and spliced leader sequences was used to obtain full-length sequences for a 2-Cys peroxiredoxin, a catalase, and a selenium-independent glutathione peroxidase, indicating that H. contortus expresses a number

  5. Two-Dimensional HYSCORE Spectroscopy of Superoxidized Manganese Catalase: A Model for the Oxygen-Evolving Complex of Photosystem II.

    PubMed

    Coates, Christopher S; Milikisiyants, Sergey; Chatterjee, Ruchira; Whittaker, Mei M; Whittaker, James W; Lakshmi, K V

    2015-04-16

    The solar water-splitting protein complex, photosystem II (PSII), catalyzes one of the most energetically demanding reactions in Nature by using light energy to drive a catalyst capable of oxidizing water. The water oxidation reaction takes place at the tetra-nuclear manganese calcium-oxo (Mn4Ca-oxo) cluster at the heart of the oxygen-evolving complex (OEC) of PSII. Previous studies have determined the magnetic interactions between the paramagnetic Mn4Ca-oxo cluster and its environment in the S2 state of the OEC. The assignments for the electron-nuclear magnetic interactions that were observed in these studies were facilitated by the use of synthetic dimanganese di-?-oxo complexes. However, there is an immense need to understand the effects of the protein environment on the coordination geometry of the Mn4Ca-oxo cluster in the OEC of PSII. In the present study, we use a proteinaceous model system to examine the protein ligands that are coordinated to the dimanganese catalytic center of manganese catalase from Lactobacillus plantarum. We utilize two-dimensional hyperfine sublevel correlation (2D HYSCORE) spectroscopy to detect the weak magnetic interactions of the paramagnetic dinuclear manganese catalytic center of superoxidized manganese catalase with the nitrogen and proton atoms of the surrounding protein environment. We obtain a complete set of hyperfine interaction parameters for the protons of a water molecule that is directly coordinated to the dinuclear manganese center. We also obtain a complete set of hyperfine and quadrupolar interaction parameters for two histidine ligands as well as a coordinated azide ligand, in azide-treated superoxidized manganese catalase. On the basis of the values of the hyperfine interaction parameters of the dimanganese model, manganese catalase, and those of the S2 state of the OEC of PSII, for the first time, we discuss the impact of a proteinaceous environment on the coordination geometry of multinuclear manganese clusters. PMID:25731604

  6. Metabolic turnover and catalase activity of biofilms of Pseudomonas fluorescens (ATCC 17552) as related to copper corrosion.

    PubMed

    Nercessian, Débora; Duville, Francisco B; Desimone, Mariela; Simison, Silvia; Busalmen, Juan Pablo

    2010-04-01

    In this work we report the results of a combined biochemical and electrochemical study aimed to analyze both the growth of biofilms of Pseudomonas fluorescens on copper samples and its possible role in the instability of the metal/electrolyte interface. DNA and RNA were quantified along the time for biofilms grown on copper and glass to estimate both the growth of the bacterial population and its metabolic state (through the RNA/DNA ratio). The expression and specific activity of catalase were also determined to gain insight into their possible role in corrosion acceleration. The electrochemical behavior of the biofilm/copper interface was monitored by Linear Polarization Resistance (Rp) and electrochemical impedance spectroscopy (EIS) along the experiments. Results showed a longer lag phase for biofilms developing on copper that included a period of high metabolic activity (as measured by the RNA/DNA ratio) without biomass growth. Biological activity introduced a new time constant at intermediate frequencies in EIS spectra whose capacitive behavior increased with the biofilm development. The increment in this biofilm-related signal was accompanied by a strong limitation to charge transfer through a diffusion controlled process probably due to oxygen exhaustion by cells respiration, while the resistance of the interface decreased presumably due to oxide dissolution by local acidification under the colonies. In addition, catalase activity was found to be high in mature copper-tolerant biofilms, which differentially express a catalase isoform not present in biofilms growing on glass. PMID:20149405

  7. Endothelin-1 upregulation mediates aging-related cardiac fibrosis.

    PubMed

    Wang, Xianwei; Guo, Zhikun; Ding, Zufeng; Khaidakov, Magomed; Lin, Juntang; Xu, Zhenping; Sharma, Shree G; Jiwani, Shahanawaz; Mehta, Jawahar L

    2015-03-01

    Endothelin-1 (ET-1) plays a major role in regulating myocardial fibrosis in several pathological conditions, such as hypertension and diabetes. Aging is an independent risk factor for myocardial fibrosis. We hypothesized that ET-1 upregulation may be a basis of enhanced collagen synthesis in the senescent fibroblasts resulting in cardiac fibrosis with aging. To examine this hypothesis, we cultured mouse cardiac fibroblasts to passage-30 (P30). ?-Galactosidase activity and several other aging markers were markedly increased in P30 (vs. P3) fibroblasts, indicating that these cells were indeed undergoing senescence. Importantly, ET-1 expression was markedly upregulated in P30 (vs. P3) fibroblasts. Of note, estrogen receptor-? (ER-?), an important negative regulator of ET-1, was downregulated in P30 fibroblasts. We also studied aged (130-weeks old, female) mice hearts, and observed that ET-1 was upregulated and ER-? was downregulated in these hearts (vs. 6-week old mice hearts, female). Similar observations were made in the fibroblasts isolated from aged mice hearts. ET-1 upregulation with aging was also seen in ?70-year old (vs. ?30-year old) human heart sections. In concert with ET-1 upregulation, the expression of fibronectin and collagens was found to be markedly increased in P30 cardiac fibroblasts in culture, fibroblasts isolated from the aged mice hearts, and in aged human hearts. Interestingly, inhibition of ET-1 in the senescent P30 fibroblasts by 2 different strategies (the use of siRNA and the use of endothelin converting enzyme inhibitors) markedly suppressed expression of fibrosis signals. Further, treatment with synthetic ET-1 enhanced fibronectin and collagen expression in P3 cardiac fibroblasts. These observations in mice and human hearts suggest that aging-related cardiac fibrosis is, at least partially, dependent on the upregulation of ET-1. PMID:25584774

  8. Refractory blood pressure in female SHR to increased oxidative stress is not mediated by NO or by upregulation of renal antioxidant enzymes

    PubMed Central

    Lopez-Ruiz, Arnaldo F.; Iliescu, Radu

    2010-01-01

    There is a sex difference in the blood pressure (BP) responses to prooxidants and antioxidants in the spontaneously hypertensive rat (SHR). In contrast to males, BP in female SHR does not decrease in response to antioxidants, such as tempol or apocynin, or increase in response to the prooxidant, molsidomine. Molsidomine decreases BP and increases expression of antioxidants in male Wistar-Kyoto rats (WKY), but not male SHR. The present study tested the hypothesis that the mechanism responsible for the lack of a pressor response to molsidomine in females is due to higher endogenous nitric oxide (NO) or to compensatory upregulation of renal antioxidant enzymes. Female SHR were treated with molsidomine in the presence or absence of nitro-l-arginine methyl ester (l-NAME) for 2 wk. Molsidomine increased nitrate/nitrite (NOx) and F2-isoprostane (F2-IsoP) excretion, whereas l-NAME reduced NOx but increased F-Isop. Molsidomine and l-NAME together further reduced NOx and increased F2-IsoP. Molsidomine alone had no effect on BP; l-NAME alone increased BP. The combination of molsidomine and l-NAME did not increase BP above l-NAME alone levels. Whole body and renal oxidative stress increased, while renal cortical Cu,Zn-SOD expression was downregulated and catalase was upregulated by molsidomine; glutathione peroxidase expression was unaffected. These data support our previous studies suggesting that BP in female SHR is independent of either increases or decreases in oxidative stress. The mechanisms responsible for the sex difference in BP response to increase or decrease of oxidative stress are not due to increased NO in females or to compensatory upregulation of antioxidant enzymes in response to increases in oxidants. PMID:20018822

  9. Cloning, characterization and phenotypic expression in Escherichia coli of catF , which encodes the catalytic subunit of catalase isozyme CatF of Pseudomonas syringae

    Microsoft Academic Search

    M. G. Klotz; Y. C. Kim; J. Katsuwon; A. J. Anderson

    1995-01-01

    The phytopathogenic, gram-negative bacterium Pseudomonas syringae pv. syringae 61 contains three isozymes of catalase (EC 1.11.1.6), which have been proposed to play a role in the bacterium's responses to various environmental stresses. To study the role of individual isozymes, the gene coding for the catalytic subunit of one catalase isozyme was cloned from a cosmid library hosted in Escherichia coli

  10. Fate of the porphyrin cofactors during the light-dependent turnover of catalase and of the photosystem II reaction-center protein D1 in mature rye leaves

    Microsoft Academic Search

    J. Feierabend; Silvia Dehne

    1996-01-01

    The apoprotein of the enzyme catalase (EC 1.11.1.6) was shown to exhibit a light-dependent turnover in leaves. Present results indicate that photoinactivation of the enzyme was not accompanied by a synchronous destruction and new synthesis of its heme moiety. In rye (Secale cereale L.) leaves the catalase content was not depleted in light when porphyrin synthesis was inhibited by gabaculine.

  11. Streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (Didelphis virginiana) with suppurative dermatitis and liver fibrosis

    Microsoft Academic Search

    Fred R. Rurangirwa; Charlene A. Teitzel; Jing Cui; Dorothy M. French; Patrick L. McDonough; Thomas Besser

    b-Haemolytic, catalase-positive, Gram-positive cocci that formed chains in broth media but did not react with Lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. The isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this

  12. E7-expressing HaCaT keratinocyte cells are resistant to oxidative stress-induced cell death via the induction of catalase.

    PubMed

    Shim, Jung-Hyun; Cho, Kyung-Joo; Lee, Kyung-Ae; Kim, Soo-Hyun; Myung, Pyung-Keun; Choe, Yong-Kyung; Yoon, Do-Young

    2005-05-01

    Cervical carcinoma is one of the most prevalent cancers in women worldwide, and human papillomavirus (HPV) type 16 is the most common agent linked to human cervical carcinoma. In order to identify various relevant factors affected by the E7 oncogene, we established a stable cell line, which constitutively expressed E7 using the HaCaT human keratinocyte cell line. The increased expression and activity of catalase in the E7-expressing HaCaT cells (HaCaT/E7) were verified via matrix-assisted laser desorption/ionization-time of flight, Western blot, and reverse transcription-polymerase chain reaction analyses. The regulation of catalase by E7 was investigated by the detection of catalase promoter activity. E7 enhanced the activities of both the catalase promoter and nuclear factor-kappaB, one of the major transcription factors regulating the expression of the catalase gene. HaCaT/E7 cells produced lower quantities of intracellular reactive oxygen species (ROS), and appeared to be more resistant to H(2)O(2)-induced cell death. Moreover, in order to test the specific effects of E7 on catalase induction, the HaCaT/E7 cells were transiently transfected with E7 antisense vector, resulting in reductions in both the expression and activity of catalase, and a recovery of intracellular ROS levels, thus resulting in recovered sensitivity to H(2)O(2)-induced cell death. These results suggest that the HPV 16 E7 oncogene induces higher resistance to ROS-induced cell injury in the E7-infected cells, probably via the modulation of several anti-oxidant enzymes, including catalase. PMID:15852342

  13. A prenatal test for the cerebro-hepato-renal (Zellweger) syndrome by demonstration of the absence of catalase-containing particles (peroxisomes) in cultured amniotic fluid cells

    Microsoft Academic Search

    R. J. A. Wanders; G. Schrakamp; H. Bosch; J. M. Tager; R. B. H. Schutgens

    1986-01-01

    In this paper we show that whereas acyl-CoA: dihydroxyacetone phosphate acyltransferase, a membranebound peroxisomal enzyme, is deficient in homogenates of cultured amniotic fluid cells of fetuses with Zellweger syndrome, catalase a soluble peroxisomal matrix enzyme is present in normal amounts. Digitonin titration experiments revealed a striking difference in the percentage of particle-bound catalase in control and Zellweger aminocytes: in Zellweger

  14. Redox-sensitive up-regulation of eNOS by purple grape juice in endothelial cells: role of PI3-kinase/Akt, p38 MAPK, JNK, FoxO1 and FoxO3a.

    PubMed

    Alhosin, Mahmoud; Anselm, Eric; Rashid, Sherzad; Kim, Jong Hun; Madeira, Socorro Vanesca Frota; Bronner, Christian; Schini-Kerth, Valérie B

    2013-01-01

    The vascular protective effect of grape-derived polyphenols has been attributable, in part, to their direct action on blood vessels by stimulating the endothelial formation of nitric oxide (NO). The aim of the present study was to determine whether Concord grape juice (CGJ), which contains high levels of polyphenols, stimulates the expression of endothelial NO synthase (eNOS) in porcine coronary artery endothelial cells and, if so, to determine the signaling pathway involved. CGJ dose- and time-dependently increased eNOS mRNA and protein levels and this effect is associated with an increased formation of NO in endothelial cells. The stimulatory effect of CGJ on eNOS mRNA is not associated with an increased eNOS mRNA stability and inhibited by antioxidants such as MnTMPyP, PEG-catalase, and catalase, and by wortmannin (an inhibitor of PI3-kinase), SB 203580 (an inhibitor of p38 MAPK), and SP 600125 (an inhibitor of JNK). Moreover, CGJ induced the formation of reactive oxygen species (ROS) in endothelial cells and this effect is inhibited by MnTMPyP, PEG-catalase, and catalase. The CGJ-induced the phosphorylation of p38 MAPK and JNK kinases is abolished by MnTMPyP. CGJ induced phosphorylation of transcription factors FoxO1 and FoxO3a, which regulate negatively eNOS expression, and this effect is prevented by MnTMPyP, PEG-catalase, wortmannin, SB203580 and SP600125. Moreover, chromatin immunoprecipitation assay indicated that the FoxO3a protein is associated with the eNOS promoter in control cells and that CGJ induced its dissociation. Thus, the present study indicates that CGJ up-regulates the expression of eNOS mRNA and protein leading to an increased formation of NO in endothelial cells. The stimulatory effect of CGJ is a redox-sensitive event involving PI3-kinase/Akt, p38 MAPK and JNK pathways, and the inactivation of the FoxO transcription factors, FoxO1 and FoxO3a, thereby preventing their repression of the eNOS gene. PMID:23533577

  15. Redox-Sensitive Up-Regulation of eNOS by Purple Grape Juice in Endothelial Cells: Role of PI3-Kinase/Akt, p38 MAPK, JNK, FoxO1 and FoxO3a

    PubMed Central

    Rashid, Sherzad; Kim, Jong Hun; Frota Madeira, Socorro Vanesca; Bronner, Christian; Schini-Kerth, Valérie B.

    2013-01-01

    The vascular protective effect of grape-derived polyphenols has been attributable, in part, to their direct action on blood vessels by stimulating the endothelial formation of nitric oxide (NO). The aim of the present study was to determine whether Concord grape juice (CGJ), which contains high levels of polyphenols, stimulates the expression of endothelial NO synthase (eNOS) in porcine coronary artery endothelial cells and, if so, to determine the signaling pathway involved. CGJ dose- and time-dependently increased eNOS mRNA and protein levels and this effect is associated with an increased formation of NO in endothelial cells. The stimulatory effect of CGJ on eNOS mRNA is not associated with an increased eNOS mRNA stability and inhibited by antioxidants such as MnTMPyP, PEG-catalase, and catalase, and by wortmannin (an inhibitor of PI3-kinase), SB 203580 (an inhibitor of p38 MAPK), and SP 600125 (an inhibitor of JNK). Moreover, CGJ induced the formation of reactive oxygen species (ROS) in endothelial cells and this effect is inhibited by MnTMPyP, PEG-catalase, and catalase. The CGJ-induced the phosphorylation of p38 MAPK and JNK kinases is abolished by MnTMPyP. CGJ induced phosphorylation of transcription factors FoxO1 and FoxO3a, which regulate negatively eNOS expression, and this effect is prevented by MnTMPyP, PEG-catalase, wortmannin, SB203580 and SP600125. Moreover, chromatin immunoprecipitation assay indicated that the FoxO3a protein is associated with the eNOS promoter in control cells and that CGJ induced its dissociation. Thus, the present study indicates that CGJ up-regulates the expression of eNOS mRNA and protein leading to an increased formation of NO in endothelial cells. The stimulatory effect of CGJ is a redox-sensitive event involving PI3-kinase/Akt, p38 MAPK and JNK pathways, and the inactivation of the FoxO transcription factors, FoxO1 and FoxO3a, thereby preventing their repression of the eNOS gene. PMID:23533577

  16. Modification of catalase and MAPK in Vicia faba cultivated in soil with high natural radioactivity and treated with a static magnetic field.

    PubMed

    Haghighat, Nazanin; Abdolmaleki, Parviz; Ghanati, Faezeh; Behmanesh, Mehrdad; Payez, Atefeh

    2014-03-01

    The effects of a static magnetic field (SMF) and high natural radioactivity (HR) on catalase and MAPK genes in Vicia faba were investigated. Soil samples with high natural radioactivity were collected from Ramsar in north Iran where the annual radiation absorbed dose from background radiation is higher than 20mSv/year. The specific activity of the radionuclides of (232)Th, (236)Ra, and (40)K was measured using gamma spectrometry. The seeds were planted either in the soil with high natural radioactivity or in the control soils and were then exposed to a SMF of 30mT for 8 days; 8h/day. Levels of expression of catalase and MAPK genes, catalase activity and H2O2 content were evaluated. The results demonstrated significant differences in the expression of catalase and MAPK genes in SMF- and HR-treated plants compared to the controls. An increase in catalase activity was accompanied by increased expression of its gene and accumulation of H2O2. Relative expression of the MAPK gene in treated plants, however, was lower than those of the controls. The results suggest that the response of V. faba plants to SMF and HR may be mediated by modification of catalase and MAPK. PMID:24484963

  17. Prognostic significance of catalase expression and its regulatory effects on hepatitis B virus X protein (HBx) in HBV-related advanced hepatocellular carcinomas

    PubMed Central

    Cho, Mi-Young; Cheong, Jae Youn; Lim, Wonchung; Jo, Sujin; Lee, Youngsoo; Wang, Hee-Jung; Han, Kyou-Hoon; Cho, Hyeseong

    2014-01-01

    Hepatitis B virus X protein (HBx) plays a role in liver cancer development. We previously showed that ROS increased HBx levels and here, we investigated the role of antioxidants in the regulation of HBx expression and their clinical relevance. We found that overexpression of catalase induced a significant loss in HBx levels. The cysteine null mutant of HBx (Cys?) showed a dramatic reduction in its protein stability. In clonogenic proliferation assays, Huh7-X cells produced a significant number of colonies whereas Huh7-Cys? cells failed to generate them. The Cys at position 69 of HBx was crucial to maintain its protein stability and transactivation function in response to ROS. Among 50 HBV-related hepatocellular carcinoma (HCC) specimens, 72% of HCCs showed lower catalase levels than those of surrounding non-tumor tissues. In advanced stage IV, catalase levels in non-tumor tissues were increased whereas those in tumors were further reduced. Accordingly, patients with a high T/N ratio for catalase showed significantly longer survival than those with a low T/N ratio. Together, catalase expression in HCC patients can be clinically useful for prediction of patient survival, and restoration of catalase expression in HCCs could be an important strategy for intervention in HBV-induced liver diseases. PMID:25361011

  18. Nutraceutical up-regulation of serotonin paradoxically induces compulsive behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role of diet in either the etiology or treatment of complex mental disorder is highly controversial in psychiatry. However, physiological mechanisms by which diet can influence brain chemistry – particularly that of serotonin – are well established. Here we show that dietary up-regulation of br...

  19. Adrenal GRK2 upregulation mediates sympathetic overdrive in heart failure

    E-print Network

    Cai, Long

    Adrenal GRK2 upregulation mediates sympathetic overdrive in heart failure Anastasios Lymperopoulos1 by the sympathetic nervous system (SNS) is a salient characteristic of heart failure, reflected by elevated circulating levels of catecholamines. The success of b-adrenergic receptor (bAR) antagonists in heart failure

  20. Cyclooxygenase-2 is Upregulated in Copper-Deficient Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copper deficiency inactivates Cu/Zn-SOD and promotes accumulation of reactive oxygen species. This process likely impairs nitric oxide (NO)-mediated relaxation as well as triggers vascular inflammation. The current study was designed to determine whether COX-2 expression and activity are upregulated...

  1. Estimation of volume densities of hepatocytic peroxisomes in a model fish: catalase conventional immunofluorescence versus cytochemistry for electron microscopy.

    PubMed

    Madureira, Tânia Vieira; Lopes, Célia; Malhão, Fernanda; Rocha, Eduardo

    2015-02-01

    Accurately accessing changes in the intracellular volumes (or numbers) of peroxisomes within a cell can be a lengthy task, because unbiased estimations can be made only by studies conducted under transmission electron microscopy. Yet, such information is often required, namely for correlations with functional data. The optimization and applicability of a fast and new technical proceeding based on catalase immunofluorescence was implemented herein by using primary hepatocytes from brown trout (Salmo trutta f. fario), exposed during 96 h to two distinct treatments (0.1% ethanol and 50 µM of 17?-ethynylestradiol). The time and cost efficiency, together with the results obtained by stereological analyses, specifically directed to the volume densities of peroxisomes, and additionally of the nucleus in relation to the hepatocyte, were compared with the well-established 3,3'-diaminobenzidine cytochemistry for electron microscopy. With the immuno technique it was possible to correctly distinguish punctate peroxisomal profiles, allowing the selection of the marked organelles for quantification. By both methodologies, a significant reduction in the volume density of the peroxisome within the hepatocyte was obtained after an estrogenic input. The most interesting point here was that the volume density ratios were quite correlated between both techniques. Overall, the immunofluorescence protocol for catalase was evidently faster, cheaper and provided reliable quantitative data that discriminated in the same way the compared groups. After this validation study, we recommend the use of catalase immunofluorescence as the first option for rapid screening of changes of the amount of hepatocytic peroxisomes, using their volume density as an indicator. PMID:25431324

  2. Cytochrome P450-type hydroxylation and epoxidation in a tyrosine-liganded hemoprotein, catalase-related allene oxide synthase.

    PubMed

    Boeglin, William E; Brash, Alan R

    2012-07-13

    The ability of hemoproteins to catalyze epoxidation or hydroxylation reactions is usually associated with a cysteine as the proximal ligand to the heme, as in cytochrome P450 or nitric oxide synthase. Catalase-related allene oxide synthase (cAOS) from the coral Plexaura homomalla, like catalase itself, has tyrosine as the proximal heme ligand. Its natural reaction is to convert 8R-hydroperoxy-eicosatetraenoic acid (8R-HPETE) to an allene epoxide, a reaction activated by the ferric heme, forming product via the Fe(IV)-OH intermediate, Compound II. Here we oxidized cAOS to Compound I (Fe(V)=O) using the oxygen donor iodosylbenzene and investigated the catalytic competence of the enzyme. 8R-hydroxyeicosatetraenoic acid (8R-HETE), the hydroxy analog of the natural substrate, normally unreactive with cAOS, was thereby epoxidized stereospecifically on the 9,10 double bond to form 8R-hydroxy-9R,10R-trans-epoxy-eicosa-5Z,11Z,14Z-trienoic acid as the predominant product; the turnover was 1/s using 100 ?m iodosylbenzene. The enantiomer, 8S-HETE, was epoxidized stereospecifically, although with less regiospecificity, and was hydroxylated on the 13- and 16-carbons. Arachidonic acid was converted to two major products, 8R-HETE and 8R,9S-eicosatrienoic acid (8R,9S-EET), plus other chiral monoepoxides and bis-allylic 10S-HETE. Linoleic acid was epoxidized, whereas stearic acid was not metabolized. We conclude that when cAOS is charged with an oxygen donor, it can act as a stereospecific monooxygenase. Our results indicate that in the tyrosine-liganded cAOS, a catalase-related hemoprotein in which a polyunsaturated fatty acid can enter the active site, the enzyme has the potential to mimic the activities of typical P450 epoxygenases and some capabilities of P450 hydroxylases. PMID:22628547

  3. Reactive oxygen species formation and cell death in catalase-deficient tobacco leaf disks exposed to cadmium

    Microsoft Academic Search

    María Florencia Iannone; Eliana Paola Rosales; María Daniela Groppa; María Patricia Benavides

    2010-01-01

    The physiological responses of tobacco (Nicotiana tabacum L.) to oxidative stress induced by cadmium were examined with respect to reactive oxygen species (ROS) formation, antioxidant\\u000a enzymes activities, and cell death appearance in wild-type SR1 and catalase-deficient CAT1AS plants. Leaf disks treated with\\u000a 100 or 500 µM CdCl2 increased Evans blue staining and leakage of electrolytes in SR1 or CAT1AS plants, more

  4. [Effects of pesticides metolachlor and S-metolachlor on soil microorganisms in aquisols of Southern China. I. Catalase activity].

    PubMed

    Zhou, Ying; Liu, Weiping; Wang, Tingting

    2005-05-01

    This paper studied the effects of different concentrations (0, 5, 20, and 100 mg.kg(-1)) metolachlor and its enantiomer S-metolachlor (Dual Gold) on soil catalase activity. The results showed that 20 mg.kg(-1) metolachlor had the most successive stimulating effect, 5 mg.kg(-1) metolachlor had an inhibitory effect in the early period, while 100 mg.kg(-1) metolachlor had a stimulating effect in the late period. Different concentrations Dual Gold displayed a tendency stimulation-inhibition-stimulation. 5 and 100 mg.kg(-1) metolachlor might have more damage on soil ecosystem than different concentrations Dual Gold. PMID:16110666

  5. Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci.

    PubMed Central

    Facklam, R; Elliott, J A

    1995-01-01

    Several new genera and species of gram-positive, catalase-negative cocci that can cause infections in humans have been described. Although these bacteria were isolated in the clinical laboratory, they were considered nonpathogenic culture contaminants and were not thought to be the cause of any diseases. Isolation of pure cultures of these bacteria from normally sterile sites has led to the conclusion that these bacteria can be an infrequent cause of infection. This review describes the new bacteria and the procedures useful for clinical laboratories to aid in their identification. The clinical relevance and our experience with the various genera and species are reviewed and discussed. PMID:8665466

  6. Purification, Biochemical Characterization, and Implications of an Alkali-Tolerant Catalase from the Spacecraft-Associated and Oxidation-Resistant Acinetobacter gyllenbergii 2P01AA.

    PubMed

    Muster, N; Derecho, I; Dallal, F; Alvarez, R; McCoy, K B; Mogul, R

    2015-04-01

    Herein, we report on the purification, characterization, and sequencing of catalase from Acinetobacter gyllenbergii 2P01AA, an extremely oxidation-resistant bacterium that was isolated from the Mars Phoenix spacecraft assembly facility. The Acinetobacter are dominant members of the microbial communities that inhabit spacecraft assembly facilities and consequently may serve as forward contaminants that could impact the integrity of future life-detection missions. Catalase was purified by using a 3-step chromatographic procedure, where mass spectrometry provided respective subunit and intact masses of 57.8 and 234.6?kDa, which were consistent with a small-subunit tetrameric catalase. Kinetics revealed an extreme pH stability with no loss in activity between pH 5 and 11.5 and provided respective kcat/Km and kcat values of ?10(7) s(-1) M(-1) and 10(6) s(-1), which are among the highest reported for bacterial catalases. The amino acid sequence was deduced by in-depth peptide mapping, and structural homology suggested that the catalases from differing strains of A. gyllenbergii differ only at residues near the subunit interfaces, which may impact catalytic stability. Together, the kinetic, alkali-tolerant, and halotolerant properties of the catalase from A. gyllenbergii 2P01AA are significant, as they are consistent with molecular adaptations toward the alkaline, low-humidity, and potentially oxidizing conditions of spacecraft assembly facilities. Therefore, these results support the hypothesis that the selective pressures of the assembly facilities impact the microbial communities at the molecular level, which may have broad implications for future life-detection missions. Key Words: Catalase-Kinetics-Sequence-Stability-Acinetobacter-Spacecraft-Planetary protection. Astrobiology 15, 291-300. PMID:25826195

  7. Upregulated Genes In Sporadic, Idiopathic Pulmonary Arterial Hypertension

    PubMed Central

    Edgar, Alasdair J; Chacón, Matilde R; Bishop, Anne E; Yacoub, Magdi H; Polak, Julia M

    2006-01-01

    Background To elucidate further the pathogenesis of sporadic, idiopathic pulmonary arterial hypertension (IPAH) and identify potential therapeutic avenues, differential gene expression in IPAH was examined by suppression subtractive hybridisation (SSH). Methods Peripheral lung samples were obtained immediately after removal from patients undergoing lung transplant for IPAH without familial disease, and control tissues consisted of similarly sampled pieces of donor lungs not utilised during transplantation. Pools of lung mRNA from IPAH cases containing plexiform lesions and normal donor lungs were used to generate the tester and driver cDNA libraries, respectively. A subtracted IPAH cDNA library was made by SSH. Clones isolated from this subtracted library were examined for up regulated expression in IPAH using dot blot arrays of positive colony PCR products using both pooled cDNA libraries as probes. Clones verified as being upregulated were sequenced. For two genes the increase in expression was verified by northern blotting and data analysed using Student's unpaired two-tailed t-test. Results We present preliminary findings concerning candidate genes upregulated in IPAH. Twenty-seven upregulated genes were identified out of 192 clones examined. Upregulation in individual cases of IPAH was shown by northern blot for tissue inhibitor of metalloproteinase-3 and decorin (P < 0.01) compared with the housekeeping gene glyceraldehydes-3-phosphate dehydrogenase. Conclusion Four of the up regulated genes, magic roundabout, hevin, thrombomodulin and sucrose non-fermenting protein-related kinase-1 are expressed specifically by endothelial cells and one, muscleblind-1, by muscle cells, suggesting that they may be associated with plexiform lesions and hypertrophic arterial wall remodelling, respectively. PMID:16390543

  8. Uromodulin Upregulates TRPV5 by Impairing Caveolin-Mediated Endocytosis

    PubMed Central

    Wolf, Matthias T.F.; Wu, Xue-Ru; Huang, Chou-Long

    2013-01-01

    Uromodulin (UMOD) is synthesized in the thick ascending limb and secreted into urine as the most abundant protein. Association studies in humans suggest protective effects of UMOD against calcium-containing kidney stones. Mice carrying mutations of Umod found in human uromodulin-associated kidney disease (UAKD) and Umod deficient mice exhibit hypercalciuria. The mechanism for UMOD regulation of urinary Ca2+ excretion is incompletely understood. We examined if UMOD regulates TRPV5 and TRPV6, channels critical for renal transcellular Ca2+ reabsorption. Coexpression with UMOD increased whole-cell TRPV5 current density in HEK293 cells. In biotinylation studies UMOD increased TRPV5 cell-surface abundance. Extracellular application of purified UMOD upregulated TRPV5 current density within physiological relevant concentration ranges. UMOD exerted a similar effect on TRPV6. TRPV5 undergoes constitutive caveolin-mediated endocytosis. UMOD had no effect on TRPV5 in a caveolin-1 deficient cell line. Expression of recombinant caveolin-1 in these cells restored the ability of UMOD to upregulate TRPV5. Secretion of UAKD-mutant UMOD was markedly reduced and coexpression of mutant UMOD with TRPV5 failed to increase its current. Immunofluorescent studies demonstrated lower TRPV5 expression in Umod?/? mice compared to wild-type. UMOD upregulates TRPV5 by acting from extracellular and by decreasing endocytosis of TRPV5. The stimulation of Ca2+ reabsorption via TRPV5 by UMOD may contribute to protection against kidney stone formation. PMID:23466996

  9. Upregulation of Trop-2 quantitatively stimulates human cancer growth.

    PubMed

    Trerotola, M; Cantanelli, P; Guerra, E; Tripaldi, R; Aloisi, A L; Bonasera, V; Lattanzio, R; de Lange, R; Weidle, U H; Piantelli, M; Alberti, S

    2013-01-10

    Trop-2 is a calcium signal transducer that is associated with transformed cell growth in experimental systems. However, its role in human cancer remains essentially unknown. In this study, we profiled Trop-2 expression in normal human tissues at the mRNA and protein levels. We then systematically compared Trop-2 mRNA and protein levels in tumours with their tissues of origin. We find that Trop-2 expression is invariably upregulated in tumours, regardless of baseline expression in normal tissues, which suggests a corresponding selective advantage. Thus, we investigated the outcome of Trop-2 upregulation on tumour growth. Overexpression of wild-type Trop-2 was shown to be necessary and sufficient to drive cancer growth in a widely invariant manner across cell type and species. Upregulation of Trop-2 was shown to quantitatively stimulate tumour growth, as proportional to expression levels in vivo, and tumour cell growth was abrogated by somatic knockdown of Trop-2 expression. On the other hand, we found no evidence of tumour-associated TROP2 mutations, nor of TROP2 induction of oncogenic transformation per se. Our data support a model where above-baseline expression of wild-type Trop-2 is a key driver of human cancer growth. PMID:22349828

  10. Contact-dependent depletion of hydrogen peroxide by catalase is a novel mechanism of myeloid-derived suppressor cell induction operating in human hepatic stellate cells.

    PubMed

    Resheq, Yazid J; Li, Ka-Kit; Ward, Stephen T; Wilhelm, Annika; Garg, Abhilok; Curbishley, Stuart M; Blahova, Miroslava; Zimmermann, Henning W; Jitschin, Regina; Mougiakakos, Dimitrios; Mackensen, Andreas; Weston, Chris J; Adams, David H

    2015-03-15

    Myeloid-derived suppressor cells (MDSC) represent a unique cell population with distinct immunosuppressive properties that have been demonstrated to shape the outcome of malignant diseases. Recently, human hepatic stellate cells (HSC) have been reported to induce monocytic-MDSC from mature CD14(+) monocytes in a contact-dependent manner. We now report a novel and unexpected mechanism by which CD14(+)HLADR(low/-) suppressive cells are induced by catalase-mediated depletion of hydrogen peroxide (H2O2). Incubation of CD14(+) monocytes with catalase led to a significant induction of functional MDSC compared with media alone, and H2O2 levels inversely correlated with MDSC frequency (r = -0.6555, p < 0.05). Catalase was detected in primary HSC and a stromal cell line, and addition of the competitive catalase inhibitor hydroxylamine resulted in a dose-dependent impairment of MDSC induction and concomitant increase of H2O2 levels. The NADPH-oxidase subunit gp91 was significantly increased in catalase-induced MDSC as determined by quantitative PCR outlining the importance of oxidative burst for the induction of MDSC. These findings represent a so far unrecognized link between immunosuppression by MDSC and metabolism. Moreover, this mechanism potentially explains how stromal cells can induce a favorable immunological microenvironment in the context of tissue oxidative stress such as occurs during cancer therapy. PMID:25667417

  11. Structural characterization of the Ser324Thr variant of the catalase-peroxidase (KatG) from Burkholderia pseudomallei.

    PubMed

    Deemagarn, Taweewat; Carpena, Xavier; Singh, Rahul; Wiseman, Ben; Fita, Ignacio; Loewen, Peter C

    2005-01-01

    The Ser315Thr variant of the catalase-peroxidase KatG from Mycobacterium tuberculosis imparts resistance to the pro-drug isonicotinic acid hydrazide (isoniazid) through a failure to convert it to the active drug, isonicotinoyl-NAD. The equivalent variant in KatG from Burkholderia pseudomallei, Ser324Thr, has been constructed, revealing catalase and peroxidase activities that are similar to those of the native enzyme. The other activities of the variant protein, including the NADH oxidase, the isoniazid hydrazinolysis and isonicotinoyl-NAD synthase activities are reduced by 60-70%. The crystal structure of the variant differs from that of the native enzyme in having the methyl group of Thr324 situated in the entrance channel to the heme cavity, in a modified water matrix in the entrance channel and heme cavity, in lacking the putative perhydroxy modification on the heme, in the multiple locations of a few side-chains, and in the presence of an apparent perhydroxy modification on the indole nitrogen atom of the active-site Trp111. The position of the methyl group of Thr324 creates a constriction or narrowing of the channel leading to the heme cavity, providing an explanation for the lower reactivity towards isoniazid and the slower rate of isonicotinoyl-NAD synthesis. PMID:15567407

  12. Specific binding and inhibition of 6-benzylaminopurine to catalase: multiple spectroscopic methods combined with molecular docking study.

    PubMed

    Xu, Qin; Lu, Yanni; Jing, Longyun; Cai, Lijuan; Zhu, Xinfeng; Xie, Ju; Hu, Xiaoya

    2014-04-01

    6-Benzylaminopurine (6-BA) is a kind of cytokinin which could regulate the activities of the antioxidant defense system of plants. In this work, its interaction with and inhibition of beef liver catalase have been systematically investigated using spectroscopic, isothermal titration calorimetric and molecular docking methods under physiological conditions. The fluorescence quenching of beef liver catalase (BLC) by 6-BA is due to the formation of 6-BA-BLC complex. Hydrogen bonds and van der Waals interactions play major roles in stabilizing the complex. The Stern-Volmer quenching constant, binding constant, the corresponding thermodynamic parameters and binding numbers were measured. The results of UV-vis absorption, three-dimensional fluorescence, synchronous fluorescence and circular dichroism spectroscopic results demonstrate that the binding of 6-BA results in the micro-environment change around tyrosine (Tyr) and tryptophan (Trp) residues of BLC. The BLC-mediated conversion of H2O2 to H2O and O2, in the presence and absence of 6-BA, was also studied. Lineweaver-Burk plot indicates a noncompetitive type of inhibition. Molecular docking study was used to find the binding sites. PMID:24412785

  13. Short-term depletion of catalase suppresses cadmium-elicited c-Jun N-terminal kinase activation and apoptosis: role of protein phosphatases.

    PubMed

    Chuang, Show-Mei; Wang, I-Ching; Hwua, Yi-Shi; Yang, Jia-Ling

    2003-01-01

    The c-Jun N-terminal kinase (JNK) is a vital stress-activated signal that can be regulated differentially under oxidant or antioxidant conditions. Recently, we have reported that activation of JNK by cadmium chloride (Cd) contributes to apoptosis in CL3 human lung adenocarcinoma cells. Although oxidative stress has been implicated in numerous biochemical effects altered by Cd, its role in Cd-elicited JNK activation has not been established. Here we report that catalase is crucial for the activation of JNK by Cd. Short-term treatment of 3-amino-1,2,4-triazole (3AT), a specific catalase inhibitor, completely suppressed the Cd-elicited JNK activation, conversely, exogenous addition of catalase increased the intensity and duration of JNK activation in Cd-treated CL3 cells. Co-administering high doses of H(2)O(2) (500-1000 micro M) with Cd also markedly decreased JNK activity, although at doses <200 micro M H(2)O(2) enhanced the Cd-elicited JNK activation in CL3 cells. 3AT also blocked JNK activation in Cd-treated normal human fibroblasts and Chinese hamster ovary cells, and in UV-irradiated CL3 cells. However, mannitol, a hydroxyl radical scavenger, did not alter the JNK activity in Cd-treated human and rodent cells. Intriguingly, sodium fluoride or okadaic acid, inhibitors for serine/threonine protein phosphatases (PP), recovered the JNK activity in CL3 cells exposed to Cd plus 3AT; however, the protein tyrosine phosphatases inhibitor sodium orthovanadate did not. Furthermore, 3AT decreased but catalase increased the Cd-induced cytotoxicity, apoptosis and procaspase-3 degradation in CL3 cells. Together, these results indicate that persistent activation of apoptotic JNK signal by Cd requires functional catalase and that short-term depletion of catalase activity may facilitate okadaic acid-sensitive PP to down-regulate the JNK activation and may predispose these cells to carcinogenic transformation upon Cd exposure. PMID:12538343

  14. In vitro and in vivo inhibitory effects of some fungicides on catalase produced and purified from white-rot fungus Phanerochaete chrysosporium.

    PubMed

    Kavakç?o?lu, Berna; Tarhan, Leman

    2014-10-01

    In this study, in vitro and in vivo effects of some commonly used fungicides, antibiotics, and various chemicals on isolated and purified catalase from Phanerochaete chrysosporium were investigated. The catalase was purified 129.10-fold by using 60% ammonium sulfate and 60% ethanol precipitations, DEAE-cellulose anion exchange and Sephacryl-S-200 gel filtration chromatographies from P. chrysosporium growth in carbon- and nitrogen-limited medium for 12 days. The molecular weight of native purified catalase from P. chrysosporium was found to be 290 ± 10 kDa, and sodium dodecyl sulfate (SDS)-PAGE results indicated that enzyme consisted of four apparently identical subunits, with a molecular weight of 72.5 ± 2.5 kDa. Kinetic characterization studies showed that optimum pH and temperature, Km and Vmax values of the purified catalase which were stable in basic region and at comparatively high temperatures were 7.5, 30°C, 289.86 mM, and 250,000 U/mg, respectively. The activity of purified catalase from P. chrysosporium was significantly inhibited by dithiothreitol (DTT), 2-mercaptoethanol, iodoacetamide, EDTA, and sodium dodecyl sulfate (SDS). It was found that while antibiotics had no inhibitory effects, 45 ppm benomyl, 144 ppm captan, and 47.5 ppm chlorothalonil caused 14.52, 10.82, and 38.86% inhibition of purified catalase, respectively. The inhibition types of these three fungicides were found to be non-competitive inhibition with the Ki values of 1.158, 0.638, and 0.145 mM and IC50 values of 0.573, 0.158, 0.010 mM, respectively. The results of in vivo experiments also showed that benomyl, captan and chlorothalonil caused 15.25, 1.96, and 36.70% activity decreases after 24-h treatments compared to that of the control. PMID:24079700

  15. Effect of dioxydine and cyclophosphane on lipid peroxidation and superoxide dismutase and catalase activities in C57Bl\\/6 and BALB\\/c mice

    Microsoft Academic Search

    A. D. Durnev; T. G. Sazontova; N. V. Guseva; S. B. Seredenin

    1996-01-01

    Twenty-four hours after intraperitoneal injection of cyclophosphane (40 mg\\/kg) and dioxydine (300 mg\\/kg) to C57Bl\\/6 mice,\\u000a liver catalase activity dropped by 29 and 23%, respectively. In BALB\\/c mice, dioxydine (but not cyclophosphane) reduced catalase\\u000a activity by 24%. Superoxide dismutase activity was lowered by cyclophosphane (but not dioxydine) in BALB\\/c mice, and by both\\u000a dioxydine and cyclophosphane in C57Bl\\/6 mice (by

  16. Electrospun regenerated cellulose nanofibrous membranes surface-grafted with polymer chains/brushes via the atom transfer radical polymerization method for catalase immobilization.

    PubMed

    Feng, Quan; Hou, Dayin; Zhao, Yong; Xu, Tao; Menkhaus, Todd J; Fong, Hao

    2014-12-10

    In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane with fiber diameters of ?200-400 nm was prepared first; subsequently, 2-hydroxyethyl methacrylate (HEMA), 2-dimethylaminoethyl methacrylate (DMAEMA), and acrylic acid (AA) were selected as the monomers for surface grafting of polymer chains/brushes via the atom transfer radical polymerization (ATRP) method. Thereafter, four nanofibrous membranes (i.e., RC, RC-poly(HEMA), RC-poly(DMAEMA), and RC-poly(AA)) were explored as innovative supports for immobilization of an enzyme of bovine liver catalase (CAT). The amount/capacity, activity, stability, and reusability of immobilized catalase were evaluated, and the kinetic parameters (Vmax and Km) for immobilized and free catalase were determined. The results indicated that the respective amounts/capacities of immobilized catalase on RC-poly(HEMA) and RC-poly(DMAEMA) nanofibrous membranes reached 78 ± 3.5 and 67 ± 2.7 mg g(-1), which were considerably higher than the previously reported values. Meanwhile, compared to that of free CAT (i.e., 18 days), the half-life periods of RC-CAT, RC-poly(HEMA)-CAT, RC-poly(DMAEMA)-CAT, and RC-poly(AA)-CAT were 49, 58, 56, and 60 days, respectively, indicating that the storage stability of immobilized catalase was also significantly improved. Furthermore, the immobilized catalase exhibited substantially higher resistance to temperature variation (tested from 5 to 70 °C) and lower degree of sensitivity to pH value (tested from 4.0 and 10.0) than the free catalase. In particular, according to the kinetic parameters of Vmax and Km, the nanofibrous membranes of RC-poly(HEMA) (i.e., 5102 ?mol mg(-1) min(-1) and 44.89 mM) and RC-poly(DMAEMA) (i.e., 4651 ?mol mg(-1) min(-1) and 46.98 mM) had the most satisfactory biocompatibility with immobilized catalase. It was therefore concluded that the electrospun RC nanofibrous membranes surface-grafted with 3-dimensional nanolayers of polymer chains/brushes would be suitable/ideal as efficient supports for high-density and reusable enzyme immobilization. PMID:25396286

  17. A note concerning acetate activation of peroxidative activity of catalases using 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid as a substrate.

    PubMed

    Baker, Warren L; Key, Christopher; Lonergan, Greg T

    2005-01-01

    Beef liver catalases showed peroxidative activity using 2,2'-azino-bis-(3-ethylbenzthiazoline)-6-sulfonic acid as the electron donor and hydrogen peroxide as the acceptor at a pH of 5. This activity was not observed at pH 7. The reaction depended on acetate concentration, although succinate and propionate could partly replace the acetate as a catalyst. Other haem proteins also catalyzed a peroxidative effect. The reaction using syringaldazine or the coupling between dimethylaminobenzoic acid and 3-methyl-2-benzothiazolinone hydrazone was less effective and less sensitive. Evidence is presented that the reaction is associated with a conformational change of the catalase. PMID:15932252

  18. Piper betle shows antioxidant activities, inhibits MCF-7 cell proliferation and increases activities of catalase and superoxide dismutase

    PubMed Central

    2012-01-01

    Background Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. Piper betle is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of P. betle on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of P. betle and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7. Methods The leaves of P. betle were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells. Results Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC50=65 ?g/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase. Conclusions Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of P. betle leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment. PMID:23153283

  19. Geniposide protects against acute alcohol-induced liver injury in mice via up-regulating the expression of the main antioxidant enzymes.

    PubMed

    Wang, Junming; Zhang, Yueyue; Liu, Ruixin; Li, Xiaobing; Cui, Ying; Qu, Lingbo

    2015-04-01

    Geniposide (GP) is one of main compounds in Gardenia jasminoides Ellis, with both medicinal and nutritional value. This study was designed to determine, for the first time, how GP from G. jasminoides protects against acute alcohol-induced liver injury, and the underlying mechanisms. Mice were orally administered alcohol (6.0 g/kg body mass) 2 h after intragastric administration of GP and bifendate, every day for 7 continuous days. Six hours after the alcohol was administered, levels of serum alanine/aspartate transaminase (ALT/AST), hepatic lipid peroxidation (LPO), glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxidase (GPx), copper- and zinc-containing superoxide dismutase (CuZn-SOD), and catalase (CAT), and mRNA expression of CuZn-SOD and CAT were assayed. The results demonstrated that GP (20.0, 40.0, or 80 mg/kg) significantly reversed the excessive, alcohol-induced elevation in both serum ALT/AST and hepatic LPO levels. Moreover, hepatic GSH, GST, GPx, CuZn-SOD, and CAT levels were all decreased in the alcohol-treated mice, whereas treatment with GP reversed these decreases. Further analysis indicated that hepatic mRNA expression of CuZn-SOD and CAT in the alcohol-treated mice was significantly down-regulated, whereas GP up-regulated such decreases. Taken together, this study shows that GP protects against acute alcohol-induced liver injury via up-regulating the expression of the main antioxidant enzymes, and thus ameliorates alcohol-induced oxidative stress injury in the liver. PMID:25730420

  20. Effect of N+ Beam Exposure on Superoxide Dismutase and Catalase Activities and Induction of Mn-SOD in Deinococcus Radiodurans

    NASA Astrophysics Data System (ADS)

    Song, Dao-jun; Chen, Ruo-lei; Shao, Chun-lin; Wu, Li-jun; Yu, Zeng-liang

    2000-10-01

    Though bacteria of the radiation-resistant Deinococcus radiodurans have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced by these bacteria were measured, and the change of SOD and CAT activities by 20 keV N+ beam exposure was examined. Their activities were increased by N+ beam exposure from 8×1014 ions/cm2 to 6×1015 ions/cm2. The treatment of H2O2 and [CHCl3 +CH3CH2OH] and the measurement of absorption spectrum showed that the increase in SOD activity was resulted from inducible activities of Mn-SOD in D. radiodurans AS1.633 by N+ beam exposure. These results suggested that this bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.

  1. [Qualitative composition of carotenoids, catalase and superoxide dismutase activities in tissues of bivalve mollusc Anadara inaequivalvis (Bruguiere, 1789)].

    PubMed

    Soldatov, A A; Gostiukhina, O L; Borodina, A V; Golovina, I V

    2013-01-01

    By using high-performance liquid chromatography, UV-VIS-spectra and mass spectra (FAB MS) in tissues of bivalve mollusc Anadara inaequivalvis (Bruguiere, 1789) there are identified seven kinds of carotenoids: trans- and cis-pectenolon, alloxanthin, pectenol A, beta-carotene, zeaxanthin, and diatoxanthin. Their quantitative ratio in hepatopancreas, gills, and foot of the animals was determined. There was revealed negative correlation (R2 about 0.9) between content of several carotenoids (trans- and cis-pectenolon, zeaxanthin, alloxanthin, and diatoxanthin) in tissues and activities of antioxidant enzymes (catalase and superoxide dismutase). The presence of competitive relations between these molecular systems is assumed and their underlying causes are discussed. PMID:24459858

  2. Hydrogen peroxide-dependent conversion of nitrite to nitrate as a crucial feature of bovine milk catalase.

    PubMed

    Silanikove, Nissim; Shapiro, Fira; Silanikove, Mayan; Merin, Uzi; Leitner, Gabriel

    2009-09-01

    The enzyme catalase is well-known to catalyze the disintegration of hydrogen peroxide to water and oxygen; however, this study shows that its main function in bovine milk is oxidation of nitrite to nitrate. This process depends on hydrogen peroxide, of which the main source appears to be hydrogen peroxide formation that is coupled to the conversion of purines--xanthine in the present study--to uric acid by milk xanthine oxidase. However, additional secondary sources of hydrogen peroxide appear to be important during the relatively long storage of milk in the gland cistern. This paper demonstrates that the oxidation of nitrite to nitrate is necessary to prevent accumulation of free radicals and oxidative products during storage of milk in the gland and during the unavoidable delay between milking and pasteurization in dairy plants. Recommendations for minimizing the deterioration in milk quality during commercial storage are presented. PMID:19722711

  3. Molecular, technological and safety characterization of Gram-positive catalase-positive cocci from slightly fermented sausages.

    PubMed

    Martín, B; Garriga, M; Hugas, M; Bover-Cid, S; Veciana-Nogués, M T; Aymerich, T

    2006-03-15

    The population of Gram-positive catalase-positive cocci from slightly fermented sausages was characterized at species and strain level by molecular techniques and some technological and hygienic aspects were also considered. Staphylococcus xylosus was the predominant species (80.8%) followed by Staphylococcus warneri (8.3%), Staphylococcus epidermidis (5.8%) Staphylococcus carnosus (4.6%), and Kocuria varians (0.4%). Proteolytic activity was observed in 23% of the isolates. The species with the highest percentage of proteolytic strains was S. warneri. Lipolytic activity was found in 45.8% of the isolates and S. xylosus was the species with the highest percentage of lipolytic isolates. Biogenic amine production was not widely distributed (only 14.6% of the isolates). Tyramine was the most intense amine produced, although by only 4.6% of the isolates. Phenylethylamine was more frequently detected (10.8% of isolates) but at lower levels. Some strains also produced putrescine (3.3%), cadaverine (2.9%), histamine (1.3%) and tryptamine (0.4%). All isolates were susceptible to linezolid and vancomicin and over 70% were resistant to penicillin G, ampicillin and sulphonamides. Most of the mecA+ strains (only 4.6% of isolates) also displayed resistance to multiple antibiotics. A reduced enterotoxigenic potential was found. Only 3.3% of isolates showed staphylococcal enterotoxins genes, all identified as entC gene. The combination of RAPD-PCR and plasmid profiling allowed the discrimination of 208 different profiles among the 240 Gram-positive catalase-positive cocci characterized, indicating a great genetic variability. PMID:16297478

  4. Oxygen-Dependent Regulation of the Expression of the Catalase Gene katA of Lactobacillus sakei LTH677

    PubMed Central

    Hertel, Christian; Schmidt, Gudrun; Fischer, Marc; Oellers, Katja; Hammes, Walter P.

    1998-01-01

    The catalase gene katA of Lactobacillus sakei LTH677 was cloned and expressed in Escherichia coli UM2, Lactobacillus casei LK1, and Lactobacillus curvatus LTH1432. The last host is a catalase-deficient plasmid-cured derivative of a starter organism used in meat fermentation. The regulation of katA expression was found to be the same in L. sakei LTH677 and the recombinant strains. The addition of H2O2 to anaerobic cultures, as well as a switch to aerobic conditions, resulted in a strong increase in KatA activity. The expression was investigated in more detail with L. sakei LTH677 and L. curvatus LTH4002. The recombinant strain LTH4002 did not accumulate H2O2 under glucose-limited aerobic conditions and remained viable in the stationary phase. Under inductive conditions, the katA-specific mRNA and the apoenzyme were synthesized de novo. Deletion derivatives of the katA promoter were produced, and the regulatory response was investigated by fusion to the ?-glucuronidase reporter gene gusA and expression in L. sakei LTH677. The fact that gene expression was subject to induction was confirmed at the level of transcription and protein synthesis. A small putative regulatory sequence of at least 25 bp was identified located upstream of the ?35 site. Competition experiments performed with L. sakei LTH677 harboring the fusion constructs consisting of the katA promoter and gusA revealed that an activator protein is involved in the transcriptional induction of katA. PMID:9546173

  5. Upregulation of Relaxin after Experimental Subarachnoid Hemorrhage in Rabbits

    PubMed Central

    Kikkawa, Yuichiro; Matsuo, Satoshi; Kurogi, Ryota; Nakamizo, Akira; Mizoguchi, Masahiro; Sasaki, Tomio

    2014-01-01

    Background. Although relaxin causes vasodilatation in systemic arteries, little is known about its role in cerebral arteries. We investigated the expression and role of relaxin in basilar arteries after subarachnoid hemorrhage (SAH) in rabbits. Methods. Microarray analysis with rabbit basilar artery RNA was performed. Messenger RNA expression of relaxin-1 and relaxin/insulin-like family peptide receptor 1 (RXFP1) was investigated with quantitative RT-PCR. RXFP1 expression in the basilar artery was investigated with immunohistochemistry. Relaxin concentrations in cerebrospinal fluid (CSF) and serum were investigated with an enzyme-linked immunosorbent assay. Using human brain vascular smooth muscle cells (HBVSMC) preincubated with relaxin, myosin light chain phosphorylation (MLC) was investigated with immunoblotting after endothelin-1 stimulation. Results. After SAH, RXFP1 mRNA and protein were significantly downregulated on day 3, whereas relaxin-1 mRNA was significantly upregulated on day 7. The relaxin concentration in CSF was significantly elevated on days 5 and 7. Pretreatment with relaxin reduced sustained MLC phosphorylation induced by endothelin-1 in HBVSMC. Conclusion. Upregulation of relaxin and downregulation of RXFP1 after SAH may participate in development of cerebral vasospasm. Downregulation of RXFP1 may induce a functional decrease in relaxin activity during vasospasm. Understanding the role of relaxin may provide further insight into the mechanisms of cerebral vasospasm. PMID:25133183

  6. Up-regulation of metallothionein gene expression in parkinsonian astrocytes.

    PubMed

    Michael, Gregory J; Esmailzadeh, Sharmin; Moran, Linda B; Christian, Lynne; Pearce, Ronald K B; Graeber, Manuel B

    2011-11-01

    The role of glial cells in Parkinson's disease (PD) is unclear. We have previously reported a striking up-regulation of DnaJB6 heat shock protein in PD substantia nigra astrocytes. Whole genome transcriptome analysis also indicated increased expression of metallothionein genes in substantia nigra and cortex of sporadic PD cases. Metallothioneins are metal-binding proteins in the CNS that are released by astrocytes and associated with neuroprotection. Metallothionein expression was investigated in 18 PD cases and 15 non-PD controls using quantitative real-time polymerase chain reaction (qRT-PCR), in situ hybridisation (ISH) and immunocytochemistry (ICC). We observed a strong increase in the expression of metallothioneins MT1E, MT1F, MT1G, MT1H, MT1M, MT1X and MT2A in both PD nigra and frontal cortex. Expression of LRP2 (megalin), the neuronal metallothionein receptor was also significantly increased. qRT-PCR confirmed metallothionein up-regulation. Astrocytes were found to be the main source of metallothioneins 1 and 2 based on ISH results, and this finding was confirmed by ICC. Our findings demonstrate metallothionein expression by reactive astrocytes in PD nigra and support a neuroprotective role for these cells. The traditional view that nigral astrocytes are non-reactive in PD is clearly incorrect. However, it is possible that astrocytes are themselves affected by the disease process which may explain their comparatively modest and previously overlooked response. PMID:21800131

  7. Advantage of Upregulation of Succinate Dehydrogenase in Staphylococcus aureus Biofilms ?

    PubMed Central

    Gaupp, Rosmarie; Schlag, Steffen; Liebeke, Manuel; Lalk, Michael; Götz, Friedrich

    2010-01-01

    Previous studies have demonstrated that various tricarboxylic acid (TCA) cycle genes, particularly the succinate dehydrogenase genes (sdhCAB), are upregulated in Staphylococcus aureus biofilms. To better study the role of this enzyme complex, an sdhCAB deletion mutant (?sdh) was constructed. Compared to the wild type (wt) the mutant was impaired in planktonic growth under aerobic conditions, excreted acetic acid could not be reused and accumulated continuously, succinate was excreted and found in the culture supernatant, and metabolome analysis with cells grown in chemically defined medium revealed reduced uptake/metabolism of some amino acids from the growth medium. Moreover, the mutant was able to counteract the steadily decreasing extracellular pH by increased urease activity. The addition of fumarate to the growth medium restored the wt phenotype. The mutant showed a small-colony variant (SCV)-like phenotype, a slight increase in resistance to various aminoglycoside antibiotics, and decreased pigmentation. The decreased growth under aerobic conditions is due to the interruption of the TCA cycle (indicated by the accumulation of succinate and acetic acid) with the consequence that many fewer reduction equivalents (NADH and FADH2) can fuel the respiratory chain. The results indicate that the TCA cycle is required for acetate and amino acid catabolism; its upregulation under biofilm conditions is advantageous under such nutrient- and oxygen-limited conditions. PMID:20207757

  8. Infections with Haemophilus species in chronic granulomatous disease: insights into the interaction of bacterial catalase and H2O2 production.

    PubMed

    Kottilil, S; Malech, H L; Gill, V J; Holland, S M

    2003-03-01

    Chronic granulomatous disease (CGD) is a rare inherited disorder in which phagocytes are incapable of generating bactericidal-reactive oxygen derivatives. Typically these patients are susceptible to life-threatening infections with catalase-producing organisms. Haemophilus species, particularly H. paraphrophilus, are not associated with CGD infections, because these organisms rarely if ever produce catalase. Haemophilus species are part of the indigenous oral microbial flora and, other than H. influenzae, are rarely recognized as pathogens. They are fastidious and require additional growth factors and capnophilic culture conditions for optimal growth and identification. Here we describe three cases of infection with non-H. influenzae (NHI) Haemophilus species in CGD patients. These organisms were catalase-negative and therefore not expected to be virulent in CGD patients, but they were also H(2)O(2) production-negative, thereby negating the putative loss of virulence of being catalase-negative. These are the first reports of NHI Haemophilus species in CGD and reinforce the critical need for careful microbiologic evaluation of infections in CGD patients. PMID:12706409

  9. Dependence of catalase photoinactivation in rye leaves on light intensity and quality and characterization of a chloroplast-mediated inactivation in red light

    Microsoft Academic Search

    William Shang; Jürgen Feierabend

    1999-01-01

    In green or etiolated rye leaves catalase was most efficiently inactivated by blue light absorbed by its prosthetic heme. Red light was ineffective at low intensity but induced marked inactivation in green leaves at higher photon flux, while far-red light was ineffective. At identical intensities of photosynthetically active radiation, Photosystem II (PS II) was equally inactivated by both blue and

  10. Catalase Activity and Thiobarbituric Acid Reactive Substances (TBARS) Production in a Rat Model of Diffuse Axonal Injury. Effect of Gadolinium and Amiloride

    Microsoft Academic Search

    Alejandro Santos; Nuno Borges; António Cerejo; António Sarmento; Isabel Azevedo

    2005-01-01

    This study evaluated the effect of mechanogated membrane ion channel blockers on brain catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) production after traumatic brain injury (TBI). A weight drop trauma model was used. Controls were sham-operated and received no weight drop. Gadolinium (GAD) or amiloride (AMI) were administered to control and experimental rats (30 min after TBI). Brain CAT

  11. EPR spectroscopy and catalase activity of manganese-bound DNA-binding protein from nutrient starved cells

    Microsoft Academic Search

    Joshua Allen Hayden; Michael P. Hendrich

    2010-01-01

    DNA-binding proteins from nutrient-starved cells (DPS) protect cells from oxidative stress by removing H2O2 and iron. A new class of DPS-like proteins has recently been identified, with DPS-like protein from Sulfolobus solfataricus (SsDPS) being the best characterized to date. SsDPS protects cells from oxidative stress and is upregulated in response to\\u000a H2O2 but also in response to iron depletion. The

  12. Revealing mechanisms of selective, concentration-dependent potentials of 4-hydroxy-2-nonenal to induce apoptosis in cancer cells through inactivation of membrane-associated catalase.

    PubMed

    Bauer, Georg; Zarkovic, Neven

    2015-04-01

    Tumor cells generate extracellular superoxide anions and are protected against superoxide anion-mediated intercellular apoptosis-inducing signaling by the expression of membrane-associated catalase. 4-Hydroxy-2-nonenal (4-HNE), a versatile second messenger generated during lipid peroxidation, has been shown to induce apoptosis selectively in malignant cells. The findings described in this paper reveal the strong, concentration-dependent potential of 4-HNE to specifically inactivate extracellular catalase of tumor cells both indirectly and directly and to consequently trigger apoptosis in malignant cells through superoxide anion-mediated intercellular apoptosis-inducing signaling. Namely, 4-HNE caused apoptosis selectively in NOX1-expressing tumor cells through inactivation of their membrane-associated catalase, thus reactivating subsequent intercellular signaling through the NO/peroxynitrite and HOCl pathways, followed by the mitochondrial pathway of apoptosis. Concentrations of 4-HNE of 1.2µM and higher directly inactivated membrane-associated catalase of tumor cells, whereas at lower concentrations, 4-HNE triggered a complex amplificatory pathway based on initial singlet oxygen formation through H2O2 and peroxynitrite interaction. Singlet-oxygen-dependent activation of the FAS receptor and caspase-8 increased superoxide anion generation by NOX1 and amplification of singlet oxygen generation, which allowed singlet-oxygen-dependent inactivation of catalase. 4-HNE and singlet oxygen cooperate in complex autoamplificatory loops during this process. The finding of these novel anticancer pathways may be useful for understanding the role of 4-HNE in the control of malignant cells and for the optimization of ROS-dependent therapeutic approaches including antioxidant treatments. PMID:25619142

  13. Catalase overexpression impairs TNF-alpha induced NF-kappaB activation and sensitizes MCF-7 cells against TNF-alpha.

    PubMed

    Lüpertz, Regine; Chovolou, Yvonni; Kampkötter, Andreas; Wätjen, Wim; Kahl, Regine

    2008-04-01

    The pleiotropic cytokine tumor necrosis factor alpha (TNF-alpha) can induce apoptosis but also supports cell survival pathways. Among the possible anti-apoptotic mechanisms of TNF-alpha is the activation of the transcription factor NF-kappaB. Since reactive oxygen species (ROS) are assumed to contribute to TNF-alpha mediated cytotoxicity but can also facilitate NF-kappaB activation this study investigates the relationship between TNF-alpha treatment, NF-kappaB activation and the expression of the anti-oxidative enzyme catalase. TNF-alpha treatment caused downregulation of catalase expression in MCF-7, Caco-2 and Hct-116 cancer cell lines. Overexpression of catalase in MCF-7 cells, resulting in lower intracellular ROS levels upon challenge with H(2)O(2), caused a transient nuclear p65 translocation upon TNF-alpha treatment as compared to the sustained NF-kappaB activation in wild type cells. This was due to a lack of sufficient H(2)O(2) to co-stimulate NF-kappaB activation as demonstrated by the observation that addition of exogenous H(2)O(2) led to a second increase of NF-kappaB activity. The rapid decline of nuclear translocation of NF-kappaB in the catalase overexpressing cells resulted in a slower increase of NF-kappaB mediated reporter gene expression. These results indicate that TNF-alpha mediated downregulation of catalase expression and accordingly sufficient H(2)O(2) is required for appropriate function of the NF-kappaB dependent survival pathway. PMID:17879952

  14. Effects of the administration of a catalase inhibitor into the fourth cerebral ventricle on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke

    PubMed Central

    Valenti, Vitor E.; de Abreu, Luiz Carlos; Fonseca, Fernando L. A.; Adami, Fernando; Sato, Monica A.; Vanderlei, Luiz Carlos M.; Ferreira, Lucas Lima; Rodrigues, Luciano M.; Ferreira, Celso

    2013-01-01

    OBJECTIVE: Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke. METHODS: Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 ?g/kg, bolus) and a depressor dose of sodium nitroprusside (50 ?g/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 ?L) into the 4th V. RESULTS: Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p<0.05) to a greater extent in WKY rats exposed to sidestream cigarette smoke than in WKY rats exposed to fresh air. However, in spontaneously hypertensive rats, the effect of the catalase inhibitor treatment was stronger in the fresh air condition (p<0.05). CONCLUSION: Administration of a catalase inhibitor into the 4th V combined with exposure to sidestream cigarette smoke has a stronger effect in WKY rats than in SH rats. PMID:23778493

  15. Upregulation of EHD2 after intracerebral hemorrhage in adult rats.

    PubMed

    Ke, Kaifu; Rui, Ying; Li, Lei; Zheng, Heyi; Xu, Wei; Tan, Xiang; Cao, Jianhua; Wu, Xiaoyan; Cui, Gang; Cao, Maohong

    2014-10-01

    EHD2, a member of the Eps15 homology domain (EH domain) family, is important for protein interactions during vesicular trafficking. Previous studies have proved that EHD2 can regulate trafficking from the plasma membrane in the process of endocytosis. However, its function in central nervous system diseases is still with limited understanding. In this frame, we found that EHD2 expression was upregulated in the perihematomal caudate in adult rats after intracerebral hemorrhage (ICH). Double immunofluorescence staining revealed that EHD2 was colocalized with neurons and activated microglias after ICH. Besides, we detected that neuronal apoptosis markers (TUNEL and caspase-3), and microglial activation marker (CD68), also known as a marker of macrophage, were colocated with EHD2. The vitro study also indicated that EHD2 was linked with neuronal apoptosis and microglial phagocytosis. All our findings suggested that EHD2 might be involved in the pathophysiology of ICH. PMID:24664435

  16. ATF4 is necessary and sufficient for ER stress-induced upregulation of REDD1 expression

    Microsoft Academic Search

    Michael L. Whitney; Leonard S. Jefferson; Scot R. Kimball

    2009-01-01

    In response to a variety of cell stresses, e.g. endoplasmic reticulum (ER) stress, expression of REDD1 (regulated in development and DNA damage responses) is transcriptionally upregulated. However, the mechanism through which ER stress acts to upregulate REDD1 expression is unknown. In the present study, REDD1 expression was found to be upregulated by ER stress in several cell lines. However, in

  17. Copper and resveratrol attenuates serum catalase, glutathione peroxidase, and element values in rats with DMBA-induced mammary carcinogenesis.

    PubMed

    Skrajnowska, Dorota; Bobrowska-Korczak, Barbara; Tokarz, Andrzej; Bialek, Slawomir; Jezierska, Ewelina; Makowska, Justyna

    2013-12-01

    In this paper, a hypothesis was assessed whether or not the intoxication with copper and supplementation with copper plus resveratrol would result in changes in the activities of catalase and glutathione peroxidase and moreover if the characteristic changes would appear in concentrations of copper, iron, calcium, magnesium, and zinc in the serum of rats with chemically induced carcinogenesis. Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet, were treated with copper (42.6 mg Cu/kg food as CuSO4·5H2O) or copper plus resveratrol (0.2 mg/kg body) via gavage for a period from 40 days until 20 weeks of age. In cancer groups, the rats were treated with a dose of 80 mg/body weight of 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) given in rapeseed oil at 50 and 80 days of age to induce mammary carcinogenesis. The control groups included the rats kept in the same conditions and fed with the same diet as the animals from the study groups, but not DMBA-treated. The activity of catalase significantly decreased in groups of rats with mammary carcinogenesis that were supplemented with copper (p < 0.05) or copper plus resveratrol (p < 0.001) in comparison with the control groups that received the same diets. In cancer groups of nonsupplemented rats, the increase of glutathione peroxidase activity was observed. The process of carcinogenesis and the applied supplementation significantly altered the concentrations of trace elements in serum, in particular as concerns iron and copper. The mean serum iron levels in rats with breast cancer were significantly lower than those in the control groups (p < 0.001). The mean serum copper levels significantly decreased in the groups of rats with mammary carcinogenesis that were supplemented with copper or copper plus resveratrol in comparison with the control groups that received the same diets (p < 0.001). The characteristic changes in iron content and the zinc/copper and zinc/iron ratios in blood may be used as one of the prognostic factors in breast cancer research. PMID:24213724

  18. Intracellular implantation of enzymes in hollow silica nanospheres for protein therapy: cascade system of superoxide dismutase and catalase.

    PubMed

    Chang, Feng-Peng; Chen, Yi-Ping; Mou, Chung-Yuan

    2014-11-01

    An approach for enzyme therapeutics is elaborated with cell-implanted nanoreactors that are based on multiple enzymes encapsulated in hollow silica nanospheres (HSNs). The synthesis of HSNs is carried out by silica sol-gel templating of water-in-oil microemulsions so that polyethyleneimine (PEI) modified enzymes in aqueous phase are encapsulated inside the HSNs. PEI-grafted superoxide dismutase (PEI-SOD) and catalase (PEI-CAT) encapsulated in HSNs are prepared with quantitative control of the enzyme loadings. Excellent activities of superoxide dismutation by PEI-SOD@HSN are found and transformation of H2 O2 to water by PEI-CAT@HSN. When PEI-SOD and PEI-CAT are co-encapsulated, cascade transformation of superoxide through hydrogen peroxide to water was facile. Substantial fractions of HSNs exhibit endosome escape to cytosol after their delivery to cells. The production of downstream reactive oxygen species (ROS) and COX-2/p-p38 expression show that co-encapsulated SOD/CAT inside the HSNs renders the highest cell protection against the toxicant N,N'-dimethyl-4,4'-bipyridinium dichloride (paraquat). The rapid cell uptake and strong detoxification effect on superoxide radicals by the SOD/CAT-encapsulated hollow mesoporous silica nanoparticles demonstrate the general concept of implanting catalytic nanoreactors in biological cells with designed functions. PMID:25160910

  19. Hexachlorocyclohexane-induced changes in lipid peroxidation, superoxide dismutase and catalase activities and glutathione content in chick liver.

    PubMed

    Samanta, L; Chainy, G B

    1995-02-01

    An elevation in the level of lipid peroxides in nuclear, mitochondrial and microsomal fractions of chick liver was recorded 6 hr after hexachlorocyclohexane (HCH; 50 mg/kg body wt., ip) treatment. The magnitude of increase remained more or less same even 24 hr after the pesticide treatment. Total glutathione content also increased by 6 hr of HCH treatment and did not change even 24 hr after the pesticide treatment. Protein content of crude homogenate and 10000 g supernatant decreased significantly 6 hr after the pesticide treatment. The magnitude of decrease was more or less same even 24 hr after the pesticide treatment. Although cytoplasmic superoxide dismutase and catalase activities (expressed as units/mg protein) did not change 24 hr after HCH treatment, a small but significant increase in superoxide dismutase activity was recorded 6 hr after HCH treatment. On the other hand when activities were expressed as units/mg tissue wt., a significant decrease in the activities of both the enzymes was recorded 6 and 24 hr after HCH treatment. Therefore, the decrease in the activities of both the enzymes in response to HCH in chick liver may be due to decrease in tissue protein content in general rather than specific decrease in the activities of the enzymes. PMID:7538972

  20. Coupled expression of Cu/Zn-superoxide dismutase and catalase in cassava improves tolerance against cold and drought stresses

    PubMed Central

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

    2013-01-01

    Recently we reported that the joint expression of cassava Cu/Zn superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) prolonged the shelf life of cassava storage-roots by the stabilization of reactive oxygen species (ROS) homeostasis after harvest. Since oxidative damage is a major feature of plants exposed to environmental stresses, transgenic cassava showing increased expression of the cytosolic MeCu/ZnSOD and the peroxisomal MeCAT1 should have improved resistance against other abiotic stresses. After cold treatment, the transgenic cassava maintained higher SOD and CAT activities and lower malendialdehyde content than those of wild type plants (WT). Detached leaves of transgenic cassava also showed slower transpirational water loss than those of WT. When plants were not watered for 30 d, transgenic lines exhibited a significant increase in water retention ability, accumulated 13% more proline and 12% less malendialdehyde than WT’s, and showed enhanced activity of SOD and CAT. These results imply that manipulation of the antioxidative mechanism allows the development of staple crops with improved tolerance to abiotic stresses. PMID:23603959

  1. Spectroscopic investigations on the effect of N-acetyl-L-cysteine-capped CdTe Quantum Dots on catalase.

    PubMed

    Sun, Haoyu; Yang, Bingjun; Cui, Erqian; Liu, Rutao

    2014-11-11

    Quantum dots (QDs) are recognized as some of the most promising semiconductor nanocrystals in biomedical applications. However, the potential toxicity of QDs has aroused wide public concern. Catalase (CAT) is a common enzyme in animal and plant tissues. For the potential application of QDs in vivo, it is important to investigate the interaction of QDs with CAT. In this work, the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots with fluorescence emission peak at 612 nm (QDs-612) on CAT was investigated by fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible (UV-vis) absorption and circular dichroism (CD) techniques. Binding of QDs-612 to CAT caused static quenching of the fluorescence, the change of the secondary structure of CAT and the alteration of the microenvironment of tryptophan residues. The association constants K were determined to be K288K=7.98×10(5)Lmol(-1) and K298K=7.21×10(5)Lmol(-1). The interaction between QDs-612 and CAT was spontaneous with 1:1 stoichiometry approximately. The CAT activity was also inhibited for the bound QDs-612. This work provides direct evidence about enzyme toxicity of QDs-612 to CAT in vitro and establishes a new strategy to investigate the interaction between enzyme and QDs at a molecular level, which is helpful for clarifying the bioactivities of QDs in vivo. PMID:24910977

  2. Mitochondrial electron transport chain complexes, catalase and markers of oxidative stress in platelets of patients with severe aluminum phosphide poisoning.

    PubMed

    Anand, R; Sharma, D R; Verma, D; Bhalla, A; Gill, K D; Singh, S

    2013-08-01

    Aluminum phosphide (ALP), a widely used fumigant and rodenticide, leads to high mortality if ingested. Its toxicity is due to phosphine that is liberated when it comes in contact with moisture. The exact site or mechanism of action of phosphine is not known, although it is widely believed that it affects mitochondrial oxidative phosphorylation. Basic serum biochemical parameters, activity of mitochondrial complexes, antioxidant enzymes and parameters of oxidative stress were estimated in the platelets of 21 patients who developed severe poisoning following ALP ingestion. These parameters were compared with 32 healthy controls and with 22 patients with shock due to other causes (cardiogenic shock (11), septic shock (9) and hemorrhagic shock (2)). The serum levels of creatine kinase-muscle brain and lactate dehydrogenase were higher in patients poisoned with ALP, whereas a significant decrease was observed in the activities of mitochondrial complexes I, II and IV. The activity of catalase was lower but the activities of superoxide dismutase and glutathione peroxidase were unaffected in them. A significant increase in lipid peroxidation and protein carbonylation was observed, whereas total blood thiol levels were lower. In patients severely poisoned with ALP, not only cytochrome c oxidase but also other complexes are involved in mitochondrial electron transport, and enzymes are also inhibited. PMID:23821638

  3. Changes in Isozyme Profiles of Catalase, Peroxidase, and Glutathione Reductase during Acclimation to Chilling in Mesocotyls of Maize Seedlings.

    PubMed Central

    Anderson, M. D.; Prasad, T. K.; Stewart, C. R.

    1995-01-01

    The response of antioxidants to acclimation and chilling in various tissues of dark-grown maize (Zea mays L.) seedlings was examined in relation to chilling tolerance and protection from chilling-induced oxidative stress. Chilling caused an accumulation of H2O2 in both the coleoptile + leaf and the mesocotyl (but not roots), and acclimation prevented this accumulation. None of the antioxidant enzymes were significantly affected by acclimation or chilling in the coleoptile + leaf or root. However, elevated levels of glutathione in acclimated seedlings may contribute to an enhanced ability to scavenge H2O2 in the coleoptile + leaf. In the mesocotyl (visibly most susceptible to chilling), catalase3 was elevated in acclimated seedlings and may represent the first line of defense from mitochondria-generated H2O2. Nine of the most prominent peroxidase isozymes were induced by acclimation, two of which were located in the cell wall, suggesting a role in lignification. Lignin content was elevated in mesocotyls of acclimated seedlings, likely improving the mechanical strength of the mesocotyl. One cytosolic glutathione reductase isozyme was greatly decreased in acclimated seedlings, whereas two others were elevated, possibly resulting in improved effectiveness of the enzyme at low temperature. When taken together, these responses to acclimation illustrate the potential ways in which chilling tolerance may be improved in preemergent maize seedlings. PMID:12228666

  4. Upregulation of aquaporin 2 water channel expression in pregnant rats.

    PubMed Central

    Ohara, M; Martin, P Y; Xu, D L; St John, J; Pattison, T A; Kim, J K; Schrier, R W

    1998-01-01

    Water retention is characteristic of pregnancy but the mechanism(s) of the altered water metabolism has yet to be elucidated. The collecting duct water channel, aquaporin 2 (AQP2), plays a pivotal role in the renal water regulation, and we hypothesized that AQP2 expression could be modified during pregnancy. Sprague-Dawley female rats were studied on days 7 (P7), 14 (P14), and 20 (P20) of pregnancy, and expression of AQP2 in papillae was examined. Nonpregnant (NP) littermates were used as controls. Plasma osmolalities were significantly lower in pregnant rats by day 7 of gestation (P7 283.8+/-1.82, P14 284.3+/-1.64, P < 0.001, P20 282. 4+/-1.32, P < 0.0001, vs. NP 291.8+/-1.06 mosmol/kgH2O). However, plasma vasopressin concentrations in pregnant rats were not significantly different than in nonpregnant rats (NP 1.03+/-0.14, P7 1.11+/-0.21, P14 1.15+/-0.21, P20 1.36+/-0.24 pg/ml, NS). The mRNA of AQP2 was increased early during pregnancy: AQP2/beta actin: P7 196+/-17.9, P14 200+/-6.8, and P20 208+/-15.5%, P < 0.005 vs. NP (100+/-11.1%). AQP2 protein was also increased during pregnancy: AQP2 protein: P7 269+/-10.0, P14 251+/-12.0, P < 0.0001, and P20 250+/-13.6%, P < 0.001 vs. NP (100+/-12.5%). The effect of V2 vasopressin receptor antagonist, OPC-31260, was then investigated. AQP2 mRNA was suppressed significantly by OPC-31260 administration to P14 rats (AQP2/beta actin: P14 with OPC-31260 39.6+/-1.7%, P < 0.001 vs. P14 with vehicle) and was decreased to the same level of expression as NP rats receiving OPC-31260. Similar findings were found with the analysis of AQP2 protein. The decreased plasma osmolality of P14 rats was not modified by OPC-31260. The results of the study indicate that upregulation of AQP2 contributes to the water retention in pregnancy through a V2 receptor-mediated effect. In addition to vasopressin, other factors may be involved in this upregulation. PMID:9486978

  5. Simulated Microgravity Induces SOST/Sclerostin Upregulation in Osteocytes

    NASA Technical Reports Server (NTRS)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocytes are theorized to be the mechanosensors and transducers of mechanical forces in bone, yet the biological mechanism of this action remains elusive. Recent evidence suggests that SOST/Sclerostin is an important regulator of mechano-transduction. To investigate the molecular mechanisms of SOST/Sclerostin regulation under in-vitro and ex-vivo unloading we used the NASA Rotating Wall Vessel(RWV) Bioreactor. For in-vitro experiments, MLOY-4 osteocytic cells were seeded at a concentration of 250,000 cells onto 3D collagen scaffold (BD). Scaffolds (4 per condition) were either rotated in a vertical 50ml NASA/bioreactor vessel at 18 rpm (unloaded), cultured in a horizontal 50 ml NASA bioreactor vessel at 18 rpm (control for the sheared environment of vertical rotating vessel), or cultured in a static T-75 cm dish (static condition ) for 7days. For ex-vivo experiments, calvaria bones were harvested from 12-week old C57/Bl6 mice and sequentially digested with type I/II collagenase to remove periosteal osteoblasts. Calvaria halves (10 per condition) were then exposed to the same set of culture conditions described above. Simulated unloading, as achieved in the NASA RWV, resulted in enlarged, round osteocytes, as assessed by H&E staining, that was reminiscent of prior reports of unloading causing loss of osteocyte morphology and dendritic network connectivity. Semiquantitative realtime qPCR and immunohistochemistry from both in-vitro and ex-vivo RWV experiments demonstrated a four-fold up-regulation of SOST/Sclerostin. Furthermore, mRNA of the transcriptional SOST enhancer Mef2C was upregulated 1.4 fold in ex-vivo calvaria subjected to unloading conditions of the NASA RWV, suggesting that Mef2C might be an important regulator of mechano-sensation. These findings are consistent with results from seven day hindlimb unloading experiments, C57/B6 females, conducted in our laboratory and validate the use of the NASA RWV as a tool to study osteocyte mechanotransduction

  6. Increasing Cancer-Specific Gene Expression by Targeting Overexpressed 51 Integrin and Upregulated Transcriptional

    E-print Network

    Kokkoli, Efie

    Increasing Cancer-Specific Gene Expression by Targeting Overexpressed 51 Integrin and Upregulated system by targeting the overexpressed cancer surface receptor 51 integrin and the upregulated liposome that specifically targets the 51 integrin and achieved increased gene expression in DLD-1

  7. Sox6 Up-Regulation by Macrophage Migration Inhibitory Factor Promotes Survival and Maintenance of Mouse

    E-print Network

    Sox6 Up-Regulation by Macrophage Migration Inhibitory Factor Promotes Survival and Maintenance, Kawakami Y, et al. (2013) Sox6 Up-Regulation by Macrophage Migration Inhibitory Factor Promotes Survival migration inhibitory factor (MIF) has important roles in supporting the proliferation and/or survival

  8. Tissue factor upregulation drives a thrombosis–inflammation circuit in relation to cardiovascular complications

    Microsoft Academic Search

    Arthur J. Chu

    2006-01-01

    The extrinsic coagulation is recognized as an 'inducible' signalling cascade resulting from tissue factor (TF) upregulation by exposure to clotting zymogen FVII upon inflammation or tissue injury. Following the substantial initiation, an array of pro- teolytic activation generates mediating signals (active serine proteases: FVIIa, FXa and FIIa) that lead to hypercoagulation with fibrin overproduction manifesting thrombosis. In addition, TF upregulation

  9. Upregulation of Heat Shock Proteins is Essential for Cold Survival during Insect Diapause

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diapause, the dormancy common to overwintering insects, evokes a unique pattern of gene expression. In the flesh fly most, but not all, of the fly’s heat shock proteins (Hsps) are upregulated. The diapause upregulated Hsps include two members of the Hsp70 family, one member of the Hsp60 family (TC...

  10. Neurobiology of Disease Transcriptional Upregulation of Cav3.2 Mediates

    E-print Network

    Campbell, Kevin P.

    Neurobiology of Disease Transcriptional Upregulation of Cav3.2 Mediates Epileptogenesis channel Cav3.2 as a central player in epileptogenesis. We show that a transient and selective upregulation of Cav3.2 subunits on the mRNA and protein levels after status epilepticus causes an increase in cellular

  11. Upregulation of FOXM1 induces genomic instability in human epidermal keratinocytes

    Microsoft Academic Search

    Muy-Teck Teh; Emilios Gemenetzidis; Tracy Chaplin; Bryan D Young; Michael P Philpott

    2010-01-01

    BACKGROUND: The human cell cycle transcription factor FOXM1 is known to play a key role in regulating timely mitotic progression and accurate chromosomal segregation during cell division. Deregulation of FOXM1 has been linked to a majority of human cancers. We previously showed that FOXM1 was upregulated in basal cell carcinoma and recently reported that upregulation of FOXM1 precedes malignancy in

  12. Cholecystokinin Is Up-Regulated in Obese Mouse Islets and Expands -Cell Mass by Increasing -Cell

    E-print Network

    Attie, Alan D.

    Cholecystokinin Is Up-Regulated in Obese Mouse Islets and Expands -Cell Mass by Increasing -Cell mass is a key factor in the pathogenesis of diabetes. We model obesity-driven -cell mass expansion.Wepreviouslyreportedthatcholecystokinin(Cck)wasthemostup-regulatedgeneinobese pancreatic islets. We now show that islet cholecystokinin (CCK) is up-regulated 500-fold by obesity

  13. Selective Th2 Upregulation by Crocus sativus: A Neutraceutical Spice

    PubMed Central

    Bani, Sarang; Pandey, Anjali; Agnihotri, Vijai K.; Pathania, Vijaylata; Singh, Bikram

    2011-01-01

    The immunomodulatory activity of an Indian neutraceutical spice, saffron (Crocus sativus) was studied on Th1 and Th2 limbs of the immune system. Oral administration of alcoholic extract of Crocus sativus (ACS) at graded dose levels from 1.56–50?mg/kg p.o. potentiated the Th2 response of humoral immunity causing the significant increases in agglutinating antibody titre in mice at a dose of 6.25?mg/kg and an elevation of CD19+ B cells and IL-4 cytokine, a signature cytokine of Th2 pathway. Appreciable elevation in levels of IgG-1 and IgM antibodies of the primary and secondary immune response was observed. However, ACS showed no appreciable expression of the Th1 cytokines IL-2 (growth factor for CD4+ T cells) and IFN-? (signature cytokine of Th1 response). A significant modulation of immune reactivity was observed in all the animal models used. This paper represents the selective upregulation of the Th2 response of the test material and suggests its use for subsequent selective Th2 immunomodulation. PMID:20953384

  14. Food Deprivation Changes Peroxisomal b-Oxidation Activity but Not Catalase Activity during Postnatal Development in Pig Tissues1,2,3

    Microsoft Academic Search

    Xing Xian Yu; James K. Drackley; Jack Odle

    Peroxisomal b-oxidation and catalase activity were investigated in liver, kidney and heart from pigs at the following timepoints: within 0.5 h after birth (0 h, unfed) and at 24 h (suckled or unsuckled), 10 d (suckled or 24-h food-deprived), 21 d (suckled or 24-h food-deprived) and 5 mo (overnight food-deprived). In liver, peroxi- somal b-oxidation increased about twofold at 24

  15. Response of catalase activity to Ag +, Cd 2+, Cr 6+, Cu 2+ and Zn 2+ in five tissues of freshwater fish Oreochromis niloticus

    Microsoft Academic Search

    Gülüzar Atli; Özlem Alptekin; Seyhan Tükel; Mustafa Canli

    2006-01-01

    Catalase (CAT, EC 1.11.1.6) is an important enzyme in antioxidant defense system protecting animals from oxidative stress. Freshwater fish Oreochromis niloticus were exposed for 96 h to different concentrations of Ag+, Cd2+, Cr6+, Cu2+ and Zn2+, known to cause oxidative stress, and subsequently CAT activities in liver, kidney, gill, intestine and brain were measured. In vivo, CAT was stimulated by all

  16. Gas–liquid flow-induced permeabilization of phospholipid bilayer membranes for regulating catalytic performance of liposome-encapsulated bovine liver catalase

    Microsoft Academic Search

    Makoto Yoshimoto; Tomotaka Natsume; Naoya Matsumoto; Hideyuki Sakamoto

    2010-01-01

    The catalytic performance of bovine liver catalase-containing liposomes (CALs) was regulated by use of the gas–liquid flow generated in an external loop airlift bubble column. The CALs were prepared by extruding through a membrane with the mean pore diameter DP of 30, 50, 80, 100, 200 or 400nm. The airlift was operated at 40°C for 5h at the superficial gas

  17. Role of glutathione redox cycle and catalase in defense against oxidative stress induced by endosulfan in adrenocortical cells of rainbow trout ( Oncorhynchus mykiss)

    Microsoft Academic Search

    J. Dorval; A. Hontela

    2003-01-01

    The role of antioxidants in maintaining the functional integrity of adrenocortical cells during in vitro exposure to endosulfan, an organochlorine pesticide, was investigated in rainbow trout (Oncorhynchus mykiss). Aminotriazole (ATA), an inhibitor of catalase (CAT), l-buthionine sulfoximine (l-BSO), an inhibitor of glutathione (GSH) synthesis, and N-acetyl cysteine (NAC), a glutathione precursor, were used to investigate the role of CAT and

  18. A teleostan homolog of catalase from black rockfish (Sebastes schlegelii): Insights into functional roles in host antioxidant defense and expressional responses to septic conditions.

    PubMed

    Elvitigala, Don Anushka Sandaruwan; Priyathilaka, Thanthrige Thiunuwan; Whang, Ilson; Nam, Bo-Hye; Lee, Jehee

    2015-05-01

    Antioxidative defense renders a significant protection against environmental stress in organisms and maintains the correct redox balance in cells, thereby supporting proper immune function. Catalase is an indispensable antioxidant in organisms that detoxifies hydrogen peroxides produced in cellular environments. In this study, we sought to molecularly characterize a homolog of catalase (RfCat), identified from black rockfish (Sebastes schlegelii). RfCat consists of a 1581 bp coding region for a protein of 527 amino acids, with a predicted molecular weight of 60 kD. The protein sequence of RfCat harbored similar domain architecture to known catalases, containing a proximal active site signature and proximal heme ligand signature, and further sharing prominent homology with its teleostan counterparts. As affirmed by multiple sequence alignments, most of the functionally important residues were well conserved in RfCat. Furthermore, our phylogenetic analysis indicates its common vertebrate ancestral origin and a close evolutionary relationship with teleostan catalases. Recombinantly expressed RfCat demonstrated prominent peroxidase activity that varied with different substrate and protein concentrations, and protected against DNA damage. RfCat mRNA was ubiquitously expressed among different tissues examined, as detected by qPCR. In addition, RfCat mRNA expression was modulated in response to pathogenic stress elicited by Streptococcus iniae and poly I:C in blood and spleen tissues. Collectively, our findings indicate that RfCat may play an indispensable role in host response to oxidative stress and maintain a correct redox balance after a pathogen invasion. PMID:25707597

  19. Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.

    PubMed

    Nie, Qiong; Gao, Guo-Li; Fan, Qing-Jie; Qiao, Guang; Wen, Xiao-Peng; Liu, Tao; Peng, Zhi-Jun; Cai, Yong-Qiang

    2015-05-25

    Abiotic stresses usually cause H2O2 accumulation, with harmful effects, in plants. Catalase may play a key protective role in plant cells by detoxifying this excess H2O2. Pitaya (Hylocereus undatus) shows broad ecological adaptation due to its high tolerance to abiotic stresses, e.g. drought, heat and poor soil. However, involvement of the pitaya catalase gene (HuCAT) in tolerance to abiotic stresses is unknown. In the present study, a full-length HuCAT3 cDNA (1870bp) was isolated from pitaya based on our previous microarray data and RACE method. The cDNA sequence and deduced amino acid sequence shared 73-77% and 75-80% identity with other plant catalases, respectively. HuCAT3 contains conserved catalase family domain and catalytic sites. Pairwise comparison and phylogenetic analysis indicated that HuCAT3 is most similar to Eriobotrya japonica CAT, followed by Dimocarpus longan CAT and Nicotiana tabacum CAT1. Expression profile analysis demonstrated that HuCAT3 is mainly expressed in green cotyledons and mature stems, and was regulated by H2O2, drought, cold and salt stress, whereas, its expression patterns and maximum expression levels varied with stress types. HuCAT activity increased as exposure to the tested stresses, and the fluctuation of HuCAT activity was consistent with HuCAT3 mRNA abundance (except for 0.5days upon drought stress). HuCAT3 mRNA elevations and HuCAT activities changes under cold stress were also in conformity with the cold tolerances among the four genotypes. The obtained results confirmed a major role of HuCAT3 in abiotic stress response of pitaya. This may prove useful in understanding pitaya's high tolerance to abiotic stresses at molecular level. PMID:25752288

  20. Relationship between posttranslational modification of transaldolase and catalase deficiency in UV-sensitive repair-deficient xeroderma pigmentosum fibroblasts and SV40-transformed human cells.

    PubMed

    Lachaise, F; Martin, G; Drougard, C; Perl, A; Vuillaume, M; Wegnez, M; Sarasin, A; Daya-Grosjean, L

    2001-06-15

    Xeroderma Pigmentosum (XP) is a rare recessively inherited human disease associated with a hypersensitivity to ultraviolet radiation. The ultraviolet component of sunlight can initiate and promote the formation of cutaneous tumors as seen in the skin cancer-prone XP patients. Previously, we have found that the low activity of the NADPH-dependent antioxydant enzyme, catalase, which we have observed in XP diploid fibroblasts and SV40-tranformed cells, could be restored by the addition of NADPH. Here we have analyzed transaldolase, which regulates NADPH levels produced by the pentose phosphate pathway in order to examine how it influences the catalase activity regulated in XP and SV40-transformed cells. We find that transaldolase activity is high in XP and SV40-transformed human fibroblasts, whereas transaldolase transcription is unchanged, suggesting that modification of transaldolase activity is due to a posttranslational modification of the protein. Two-dimensional electrophoresis analysis has allowed us to identify a complex set of transaldolase isoforms and to postulate that the phosphorylation of specific isoforms could be correlated with the different enzymatic activities seen. Our results show that high transaldolase activity corresponds to a low catalase activity in SV40-transformed cells and in fibroblasts from XP patients who have a high predisposition to develop skin cancer. PMID:11390181

  1. The peroxidase/catalase-like activities of MFe?O? (M=Mg, Ni, Cu) MNPs and their application in colorimetric biosensing of glucose.

    PubMed

    Su, Li; Qin, Wenjie; Zhang, Huige; Rahman, Zia Ur; Ren, Cuiling; Ma, Sudai; Chen, Xingguo

    2015-01-15

    MFe2O4 (M=Mg, Ni, Cu) magnetic nanoparticles (MNPs) were found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase. These nanomaterials, as bifunctional catalase/peroxidases (KatGs), not only could catalyze H2O2 to produce hydroxyl radicals, which oxidized peroxidase substrate to produce color, but also could catalyze the decomposition reaction of H2O2 into water and oxygen directly in the same condition through the catalase-like activity. And it was also found that the amount of generated hydroxyl radicals and oxygen was related to the concentration of MFe2O4 (M=Mg, Ni, Cu) MNPs. The peroxidase-like catalytic behavior of MFe2O4 MNPs was analyzed in detail. Under the optimized conditions, NiFe2O4 MNPs were used as a colorimetric biosensor for the detection of 9.4×10(-7)-2.5×10(-5) mol L(-1) glucose with a limit of detection (LOD) of 4.5×10(-7) mol L(-1). The sensor was successfully applied to glucose detection in urine sample. PMID:25127473

  2. Environmental Lead Exposure, Catalase Gene, and Markers of Antioxidant and Oxidative Stress Relation to Hypertension: An Analysis Based on the EGAT Study.

    PubMed

    Sirivarasai, Jintana; Kaojarern, Sukhumpun; Chanprasertyothin, Suwannee; Panpunuan, Pachara; Petchpoung, Krittaya; Tatsaneeyapant, Aninthita; Yoovathaworn, Krongtong; Sura, Thunyachai; Kaojarern, Sming; Sritara, Piyamit

    2015-01-01

    Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28??g/dL) compared to normotensive (4.41??g/dL) and prehypertensive (4.55??g/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06??g/dL and 9.67??mol/L) than those with CC genotype (5.32??g/dL and 8.31??mol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension. PMID:25793211

  3. Cardiovascular responses induced by Catalase Inhibitior into the Fourth Cerebral Ventricle is changed in Wistar rats exposed to sidestream cigarette smoke

    PubMed Central

    Valenti, Vitor E.; de Abreu, Luiz Carlos; Fonseca, Fernando L. A.; Figueiredo, Jose-Luiz; Adami, Fernando; Ferreira, Celso

    2013-01-01

    Objectives This experimental study aimed to evaluate the effects of central catalase inhibition on cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS) for 3 weeks. Methodology A total of 20 males Wistar rats (320–370g) were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4thV). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS for three weeks, 180 minutes per day, 5 days/week [carbon monoxide (CO): 100–300 ppm)]. Baroreflex was tested with one pressor dose of phenylephrine (PHE, 8 ?g/kg, bolus) and one depressor dose of sodium nitroprusside (SNP, 50 ?g/kg, bolus). Cardiovascular responses were evaluated before and 15 minutes after 3-amino-1, 2, 4-triazole (ATZ, catalase inhibitor, 0.001g/100?L) injection into the 4th V. Results Vehicle treatment into the 4th V did not change cardiovascular responses. Central catalase inhibition increased tachycardic peak, attenuated bradycardic peak and reduced HR range at 15 minutes, increased MAP at 5, 15 and 30 min and increased HR at 5 and 15 min. In rats exposed to SSCS, central ATZ increased basal MAP after 5 min and increased HR at 5, 15 and 30 minutes, respectively, and attenuated bradycardic peak at 15 minutes. Conclusion This study suggests that brain oxidative stress caused by SSCS influences autonomic regulation of the cardiovascular system. PMID:24421748

  4. Environmental Lead Exposure, Catalase Gene, and Markers of Antioxidant and Oxidative Stress Relation to Hypertension: An Analysis Based on the EGAT Study

    PubMed Central

    Kaojarern, Sukhumpun; Chanprasertyothin, Suwannee; Panpunuan, Pachara; Petchpoung, Krittaya; Tatsaneeyapant, Aninthita; Yoovathaworn, Krongtong; Sura, Thunyachai; Kaojarern, Sming; Sritara, Piyamit

    2015-01-01

    Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28??g/dL) compared to normotensive (4.41??g/dL) and prehypertensive (4.55??g/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06??g/dL and 9.67??mol/L) than those with CC genotype (5.32??g/dL and 8.31??mol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension.

  5. Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens.

    PubMed

    Liu, Yongxiang; Guo, Yuming; Wang, Zhong; Nie, We

    2007-08-01

    The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3 x 3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens. The birds were fed with the basal diet alone or supplemented with magnesium (Mg) at 0.9, 1.8, 2.7 g/kg of the diet from MgO, MgAsp or MgdiAsp. Results showed that hepatic Mg concentration increased quadratically as MgO or MgAsp supplementation increased (p < 0.01). Hepatic CAT activity increased linearly in birds fed with MgAsp or MgdiAsp (p < 0.01) and quadratically in birds fed with MgO (p < 0.05) as dietary Mg supplementation level increased. Hepatic CAT mRNA was linearly correlated with the dietary Mg supplementation level (p < 0.01). There were positive correlations among hepatic CAT activity, its mRNA expression level and hepatic Mg concentration (p < 0.01). No effect of Mg2+ on the purified CAT activity was detected in vitro enzymatic reaction system (p > 0.05). Supplemental MgAsp or MgdiAsp was more efficient to increase hepatic Mg concentrations, enhance hepatic CAT activity and its mRNA expression than MgO (p < 0.01). It can be concluded that dietary Mg supplementation could increase hepatic Mg concentration, enhance CAT mRNA expression and consequently enhance CAT activity, and the organic Mg (MgAsp or MgdiAsp) is much more efficient than the inorganic form (MgO). PMID:17760306

  6. Attenuation of Experimental Colitis in Glutathione Peroxidase 1 and Catalase Double Knockout Mice through Enhancing Regulatory T Cell Function

    PubMed Central

    Choi, Eun-Jeong; Kie, Jeong-Hae; Lim, Woosung; Lee, Hyeon Kook; Moon, Byung-In; Seoh, Ju-Young

    2014-01-01

    Reactive oxygen species (ROS) have been implicated in the progression of inflammatory diseases including inflammatory bowel diseases (IBD). Meanwhile, several studies suggested the protective role of ROS in immune-mediated inflammatory diseases, and it was recently reported that dextran sodium sulfate (DSS)-induced colitis was attenuated in mice with an elevated level of ROS due to deficiency of peroxiredoxin II. Regulatory T cells (Tregs) are critical in the prevention of IBD and Treg function was reported to be closely associated with ROS level, but it has been investigated only in lowered levels of ROS so far. In the present study, in order to clarify the relationship between ROS level and Treg function, and their role in the pathogenesis of IBD, we investigated mice with an elevated level of ROS due to deficiency of both glutathione peroxidase (GPx)-1 and catalase (Cat) for the susceptibility of DSS-induced colitis in association with Treg function. The results showed that DSS-induced colitis was attenuated and Tregs were hyperfunctional in GPx1?/? × Cat?/? mice. In vivo administration of N-acetylcysteine (NAC) aggravated DSS-induced colitis and decreased Treg function to the level comparable to WT mice. Attenuated Th17 cell differentiation from naïve CD4+ cells as well as impaired production of IL-6 and IL-17A by splenocytes upon stimulation suggested anti-inflammatory tendency of GPx1?/? × Cat?/? mice. Suppression of Stat3 activation in association with enhancement of indoleamine 2,3-dioxygenase and FoxP3 expression might be involved in the immunosuppressive mechanism of GPx1?/? × Cat?/? mice. Taken together, it is implied that ROS level is critical in the regulation of Treg function, and IBD may be attenuated in appropriately elevated levels of ROS. PMID:24743300

  7. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker)*

    PubMed Central

    Chen, Shi-chao; Liu, Xiao-qing; Jiang, Wen; Li, Ke-feng; Du, Jun; Shen, Dan-zhou; Gong, Quan

    2012-01-01

    Total dissolved gas (TDG) supersaturation caused by dam sluicing can result in gas bubble trauma (GBT) in fish and threaten their survival. In the present study, Chinese suckers (Myxocyprinus asiaticus Bleeker) were exposed to TDG supersaturated water at levels ranging from 120% to 145% for 48 h. The median lethal concentration (LC50) and the median lethal time (LT50) were determined to evaluate acute lethal effects on Chinese suckers. The results showed that the LC50 values of 4, 6, 8, and 10 h were 142%, 137%, 135%, and 130%, respectively. The LT50 values were 3.2, 4.7, 7.8, 9.2, and 43.4 h, respectively, when TDG supersaturated levels were 145%, 140%, 135%, 130%, and 125%. Furthermore, the biological responses in Chinese suckers were studied by assaying the catalase (CAT) activities in gills and muscles at the supersaturation level of 140% within LT50. The CAT activities in the gills and muscle tissues exhibited a regularity of a decrease after an increase. CAT activities in the muscles were increased significantly at 3/5LT50 (P<0.05) and then came back to the normal level. However, there were no significant differences between the treatment group (TDG level of 140%) and the control group (TDG level of 100%) on CAT activities in the gills before 3/5LT50 (P>0.05), but the activities were significantly lower than the normal level at 4/5LT50 and LT50 (P<0.05). PMID:23024046

  8. The role of CYBA (p22phox) and catalase genetic polymorphisms and their possible epistatic interaction in cervical cancer.

    PubMed

    Castaldo, Stephanie Anais; da Silva, Alda Pereira; Matos, Andreia; Inácio, Ângela; Bicho, Manuel; Medeiros, Rui; Alho, Irina; Bicho, Maria Clara

    2015-02-01

    Human papillomavirus (HPV) infection is necessary but not a sufficient cause for the development of invasive cervical cancer (ICC). Epithelial tissues, target for HPV, are exposed to reactive oxygen species (ROS) associated with tumor initiation and progression. The NADPH oxidase (NOX) and catalase (CAT) are involved in hydrogen peroxide (H2O2) production and inactivation, respectively. P22phox is the NOX subunit encoded by the CYBA gene that has a functional polymorphism (C-242T). This protein is involved in the regulation of electron transfer to oxygen. CAT is a hemic enzyme that plays a role in regulating H2O2 concentration, with a functional polymorphism (C-262T) in its gene. We evaluated CYBA C-242T and CAT C262T genetic polymorphisms and their interaction in 132 women with ICC. We found that CYBA C-242T and CAT C262T genotype frequencies were significantly different between ICC and controls (? (2) test, p?=?0.017 and p?=?0.009, respectively). Women with the C/T CYBA-242 genotype had a lower risk for ICC development (odds ratio (OR)?=?0.515, 95 % confidence interval (CI) 0.291-0.914, p?=?0.023) whereas T/T CAT-262 genotype carriers present an increased risk for ICC (OR?=?3.034, 95 % CI 1.462-6.298, p?=?0.003). Women with C/C genotype for CYBA and T/T genotype for CAT had an increased risk to develop ICC comparing with the interaction of the other possible genotypes of both genes (OR?=?3.952, 95 % CI 1.075-14.521, p?=?0.032). The CYBA C-242T and CAT C-262T genetic polymorphisms and their epistatic interactions can be associated with ICC through mechanisms related with the role of ROS in cell proliferation and apoptosis. PMID:25307973

  9. Nicergoline improves dysphagia by upregulating substance P in the elderly.

    PubMed

    Nakashima, Taku; Hattori, Noboru; Okimoto, Mafumi; Yanagida, Jitsuro; Kohno, Nobuoki

    2011-07-01

    Dysphagia induces silent aspiration, which is a known risk factor for aspiration pneumonia in the elderly. Dysphagia is associated with impaired substance P secretion. Because nicergoline was recently reported to enhance substance P secretion, it may improve dysphagia by upregulating substance P; however, roles for nicergoline in this process have not been demonstrated. We therefore compared the effects of nicergoline on serum substance P and dysphagia with the effects of imidapril, an angiotensin-converting enzyme (ACE) inhibitor whose efficacy in improving dysphagia and preventing pneumonia has been previously demonstrated.We randomly assigned 60 elderly patients with both dysphagia and a previous history of pneumonia to receive either imidapril (5 mg/d; n = 30) or nicergoline (15 mg/d; n = 30) for 6 months. Primary outcomes were the effects of these drugs on the substance P level and dysphagia 4 weeks after the start of treatment. Secondary outcome was the effect of these drugs on pneumonia recurrence during the 6 months of treatment.Significant elevations of serum substance P were obtained by both medications after 4 weeks of treatment. Patients whose dysphagia was improved showed significantly increased serum levels of substance P. There was no statistically significant difference in the overall proportion of patients who showed improvements in dysphagia and pneumonia recurrence with imidapril or nicergoline treatment. Nicergoline, but not imidapril, seemed to be more effective at improving dysphagia and elevating serum substance P in patients with dementia.In conclusion, nicergoline has a comparable effect to ACE inhibitors for improving dysphagia. Nicergoline might be a novel regimen for the treatment of dysphagia in the elderly who are not treatable with ACE inhibitors. PMID:21694649

  10. Sulfur dioxide upregulates the aortic nitric oxide pathway in rats.

    PubMed

    Li, Junling; Li, Ruijin; Meng, Ziqiang

    2010-10-25

    Sulfur dioxide (SO(2)) is a common gaseous pollutant. It is also, however, endogenously generated from sulfur-containing amino acids. Recent studies have demonstrated that rat blood pressure can be lowered by SO(2)-exposure in vivo and that vasodilation caused by SO(2) at low concentrations (<450 microM) is endothelium-dependent in rat aorta. However, effects of SO(2) on nitric oxide synthase (NOS) and nitric oxide (NO) production have not been previously studied in rat aorta. The objective of the present study is to assess the effects of acute (10 min) and prolonged (2h) stimulation with different concentrations of SO(2) on NO/cGMP pathway in isolated rat aorta. The results show that: (1) the acute and prolonged pretreatments with SO(2) produced an inhibition of vasoconstrictions induced by norepinephrine. (2) SO(2) potentiated activity of endothelial nitric oxide synthase (eNOS), but not of induced NOS (iNOS). (3) SO(2) could increase expression of eNOS gene on the transcription and translation levels in rat aorta. (4) SO(2) enhanced NO formation in aortic tissue. (5) The level of cGMP in rat aorta was increased by SO(2) and no change of cAMP. These findings led to the conclusion: there were acute and prolonged effects of SO(2) on the NO/cGMP signalling pathway; and SO(2) could upregulate the eNOS-NO-cGMP pathway and at least partly by which the SO(2) might cause vasodilation and inhibition to vasoconstriction. PMID:20674563

  11. Cystatin SN Upregulation in Patients with Seasonal Allergic Rhinitis

    PubMed Central

    Imoto, Yoshimasa; Tokunaga, Takahiro; Matsumoto, Yuri; Hamada, Yuko; Ono, Mizuho; Yamada, Takechiyo; Ito, Yumi; Arinami, Tadao; Okano, Mitsuhiro; Noguchi, Emiko; Fujieda, Shigeharu

    2013-01-01

    Seasonal allergic rhinitis (SAR) to the Japanese cedar, Cryptomeria japonica (JC) pollen is an IgE-mediated type I allergy affecting nasal mucosa. However, the molecular events underlying its development remain unclear. We sought to identify SAR-associated altered gene expression in nasal epithelial cells during natural exposure to JC pollen. We recruited study participants in 2009 and 2010 and collected nasal epithelial cells between February and April, which is the period of natural pollen dispersion. Fifteen patients with SAR-JC and 13 control subjects were enrolled in 2009, and 17 SAR-JC patients, 13 sensitized asymptomatic subjects (Sensitized), and 15 control subjects were enrolled in 2010. Total RNA was extracted from nasal epithelial cells and 8 SAR-JC patients and 6 control subjects in 2009 were subjected to microarray analysis with the Illumina HumanRef-8 Expression BeadChip platform. Allergen-stimulated histamine release was examined in the peripheral blood basophils isolated from patients with SAR. We identified 32 genes with significantly altered expression during allergen exposure. One of these, CST1 encodes the cysteine protease inhibitor, cystatin SN. CST1 expression in nasal epithelial cells was significantly upregulated in both the 2009 and 2010 SAR-JC groups compared with the control groups. Immunohistochemical staining confirmed the increased expression of CST1 in the nasal epithelial cells of SAR patients. Addition of exogenous CST1 to basophils inhibited JC allergen-stimulated histamine release in vitro. We propose that CST1 may contribute to inactivation of protease allergens and help re-establish homeostasis of the nasal membranes. PMID:23950865

  12. Upregulation of GPR109A in Parkinson’s Disease

    PubMed Central

    Wakade, Chandramohan; Chong, Raymond; Bradley, Eric; Thomas, Bobby; Morgan, John

    2014-01-01

    Background Anecdotal animal and human studies have implicated the symptomatic and neuroprotective roles of niacin in Parkinson’s disease (PD). Niacin has a high affinity for GPR109A, an anti-inflammatory receptor. Niacin is also thought to be involved in the regulation of circadian rhythm. Here we evaluated the relationships among the receptor, niacin levels and EEG night-sleep in individuals with PD. Methods and Findings GPR109A expression (blood and brain), niacin index (NAD-NADP ratio) and cytokine markers (blood) were analyzed. Measures of night-sleep function (EEG) and perceived sleep quality (questionnaire) were assessed. We observed significant up-regulation of GPR109A expression in the blood as well as in the substantia nigra (SN) in the PD group compared to age-matched controls. Confocal microscopy demonstrated co-localization of GPR109A staining with microglia in PD SN. Pro and anti-inflammatory cytokines did not show significant differences between the groups; however IL1-?, IL-4 and IL-7 showed an upward trend in PD. Time to sleep (sleep latency), EEG REM and sleep efficiency were different between PD and age-matched controls. Niacin levels were lower in PD and were associated with increased frequency of experiencing body pain and decreased duration of deep sleep. Conclusions The findings of associations among the GPR109A receptor, niacin levels and night-sleep function in individuals with PD are novel. Further studies are needed to understand the pathophysiological mechanisms of action of niacin, GPR109A expression and their associations with night-sleep function. It would be also crucial to study GPR109A expression in neurons, astrocytes, and microglia in PD. A clinical trial to determine the symptomatic and/or neuroprotective effect of niacin supplementation is warranted. PMID:25329911

  13. Functional upregulation of system xc- by fibroblast growth factor-2.

    PubMed

    Liu, Xiaoqian; Resch, Jon; Rush, Travis; Lobner, Doug

    2012-02-01

    The cystine/glutamate antiporter (system xc-) is a Na(+)-independent amino acid transport system. Disruption of this system may lead to multiple effects in the CNS including decreased cellular glutathione. Since multiple neurological diseases involve glutathione depletion, and disruption of growth factor signaling has also been implicated in these diseases, it is possible that some growth factors effects are mediated by regulation of system xc-. We tested the growth factors fibroblast growth factor-2 (FGF-2), insulin-like growth factor-1 (IGF-1), neuregulin-1 (NRG), neurotrophin-4 (NT-4), and brain derived neurotrophic factor (BDNF) on system xc- mediated 14C-cystine uptake in mixed neuronal and glial cortical cultures. Only FGF-2 significantly increased cystine uptake. The effect was observed in astrocyte-enriched cultures, but not in cultures of neurons or microglia. The increase was blocked by the system xc- inhibitor (s)-4-carboxyphenylglycine, required at least 12 h FGF-2 treatment, and was prevented by the protein synthesis inhibitor cycloheximide. Kinetic analysis indicated FGF-2 treatment increased the V(max) for cystine uptake while the K(m) remained the same. Quantitative PCR showed an increase in mRNA for xCT, the functional subunit of system xc-, beginning at 3 h of FGF-2 treatment, with a dramatic increase after 12 h. Blocking FGFR1 with PD 166866 blocked the FGF-2 effect. Treatment with a PI3-kinase inhibitor (LY-294002) or a MEK/ERK inhibitor (U0126) for 1 h prior to and during the FGF-2 treatment, each partially blocked the increased cystine uptake. The upregulation of system xc- by FGF-2 may be responsible for some of the known physiological actions of FGF-2. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'. PMID:21967732

  14. Effects of aluminum sulphate and citric acid ingestion on lipid peroxidation and on activities of superoxide dismutase and catalase in cerebral hemisphere and liver of developing young chicks.

    PubMed

    Swain, C; Chainy, G B

    1998-10-01

    Effect of oral administration of aluminum sulphate (200 and 400 mg/kg body wt/day) without or with citric acid (62 mg/kg body wt/day) to day-old White Leghorn male chicks (n = 5 per group) for 30 days was studied on the activities of superoxide dismutase (SOD) and catalase, and level of lipid peroxidation in cerebral hemisphere and liver. A 400 mg dose of Al in the presence of citric acid inhibited cytosolic total and CN -sensitive superoxide dismutase activities of the cerebral hemisphere in 7- and 30-day treated chicks, whereas in 15-day treated chicks the enzyme activities were decreased in response to both doses in the presence of citric acid. In case of liver, activities of these enzymes significantly decreased after 7, 15 and 30 days of treatment with 200 and 400 mg Al together with citric acid, whereas 400 mg Al alone inhibited the enzyme activities after 15 and 30 days of treatment. Cerebral catalase activity decreased in response to 400 mg Al when the chicks were also fed with citric acid for 7 and 30 days, but in 15-day treated chicks the enzyme activity was depleted following treatment with 200 and 400 mg Al combined with citric acid. 400 mg Al treatment for 7 days in combination with citric acid inhibited hepatic catalase activity and extension of the treatment period to 15 and 30 days also produced reduction in its activity even in response to the lower Al dose mixed with citric acid. CN -insensitive SOD activity of cerebral hemisphere and liver was unaffected by Al. Al also failed to induce lipid peroxidation in both the tissues throughout the course of exposure. Activities of SOD and catalase of cerebral hemisphere and liver of 30-day old chicks were observed to be inhibited by in vitro incubation with different concentrations of Al. Our in vivo study demonstrates that only CN -sensitive SOD is susceptible to Al. Further, responses of SOD and catalase to Al is tissue specific. The observed inhibition of antioxidant enzyme activities by Al is suggestive of a prooxidant state. Induction of such an oxidative condition of the tissues may be attributed to a direct effect of the metal on enzyme molecules or in their synthesis. PMID:9788754

  15. Production of a Heterologous Nonheme Catalase by Lactobacillus casei: an Efficient Tool for Removal of H2O2 and Protection of Lactobacillus bulgaricus from Oxidative Stress in Milk

    Microsoft Academic Search

    Tatiana Rochat; Jean-Jacques Gratadoux; Alexandra Gruss; Gerard Corthier; Emmanuelle Maguin; Philippe Langella; Maarten van de Guchte

    2006-01-01

    Lactic acid bacteria (LAB) are generally sensitive to H2O2, a compound that they can paradoxically produce themselves, as is the case for Lactobacillus bulgaricus. Lactobacillus plantarum ATCC 14431 is one of the very few LAB strains able to degrade H2O2 through the action of a nonheme, manganese-dependent catalase (hereafter called MnKat). The MnKat gene was expressed in three catalase-deficient LAB

  16. Chronic intermittent hypobaric hypoxia protects the heart against ischemia/reperfusion injury through upregulation of antioxidant enzymes in adult guinea pigs

    PubMed Central

    Guo, Hui-cai; Zhang, Zhe; Zhang, Li-nan; Xiong, Chen; Feng, Chen; Liu, Qian; Liu, Xu; Shi, Xiao-lu; Wang, Yong-li

    2009-01-01

    Aim: To investigate the protection and the anti-oxidative mechanism afforded by chronic intermittent hypobaric hypoxia (CIHH) against ischemia/reperfusion (I/R) injury in guinea pig hearts. Methods: Adult male guinea pigs were exposed to CIHH by mimicking a 5000 m high altitude (pB=404 mmHg, pO2=84 mmHg) in a hypobaric chamber for 6 h/day for 28 days. Langendorff-perfused isolated guinea pig hearts were used to measure variables of left ventricular function during baseline perfusion, ischemia and the reperfusion period. The activity and protein expression of antioxidant enzymes in the left myocardium were evaluated using biochemical methods and Western blotting, respectively. Intracellular reactive oxygen species (ROS) were assessed using ROS-sensitive fluorescence. Results: After 30 min of global no-flow ischemia followed by 60 min of reperfusion, myocardial function had better recovery rates in CIHH guinea pig hearts than in control hearts. The activity and protein expression of superoxide dismutase (SOD) and catalase (CAT) were significantly increased in the myocardium of CIHH guinea pigs. Pretreatment of control hearts with an antioxidant mixture containing SOD and CAT exerted cardioprotective effects similar to CIHH. The irreversible CAT inhibitor aminotriazole (ATZ) abolished the cardioprotection of CIHH. Cardiac contractile dysfunction and oxidative stress induced by exogenous hydrogen peroxide (H2O2) were attenuated by CIHH and CAT. Conclusions: These data suggest that CIHH protects the heart against I/R injury through upregulation of antioxidant enzymes in guinea pig. PMID:19543301

  17. Human monocyte CD14 is upregulated by lipopolysaccharide.

    PubMed Central

    Landmann, R; Knopf, H P; Link, S; Sansano, S; Schumann, R; Zimmerli, W

    1996-01-01

    Membrane CD14 is involved in lipopolysaccharide (LPS)-induced monocyte activation; it binds LPS, and antibodies against CD14 block the effects of low-dose LPS. It is unknown how LPS regulates its own receptor CD14 in vitro. Therefore, we investigated the effects of LPS on CD14 mRNA and membrane and soluble CD14 (mCD14 and sCD14, respectively) in human monocytes and macrophages. No changes were observed during the first 3 h of LPS stimulation. After 6 to 15 h, LPS weakly reduced CD14 mRNA and mCD14 and transiently enhanced sCD14 release. A 2-day incubation with LPS caused increases in the levels of CD14 mRNA (2-fold), mCD14 (2-fold), sCD14 (1.5-fold), and LPS-fluorescein isothiocyanate binding (1.5-fold); a 5-h incubation with LPS was sufficient to induce the late effects on mCD14 and sCD14. The maximal effect on mCD14 and sCD14 was reached with > or = 1 ng of LPS per ml; the proportional distribution of the two sCD14 isoforms was not modified by LPS. Besides rough and smooth LPS, lipid A, heat-killed Escherichia coli, lipoteichoic acid, and Staphylococcus aureus cell wall extract (10 micrograms/ml) caused similar increases of mCD14. The LPS effect was blocked by polymyxin B but not by anti-tumor necrosis factor alpha, anti-interleukin-6, anti-gamma interferon, and anti-LPS-binding protein. LPS-induced tumor necrosis factor alpha production was abolished after a second 4-h challenge. In contrast, the LPS-induced increases CD14 mRNA, mCD14, and sCD14 were stronger and appeared earlier after a second LPS challenge. In conclusion, CD14 is transcriptionally upregulated by LPS and other bacterial cell wall constituents. PMID:8613389

  18. INTEGRIN-MEDIATED CELL ATTACHMENT SHOWS TIME-DEPENDENT UPREGULATION OF GAP JUNCTION COMMUNICATION.

    EPA Science Inventory

    Integrin-mediated Cell Attachment Shows Time-Dependent Upregulation of Gap Junction Communication Rachel Grindstaff and Carl Blackman, National Health & Environmental Effects Research Laboratory, Office of Research and Development, US EPA, Research Triang...

  19. TGF-?1 up-regulates connexin43 expression: A potential mechanism for human trophoblast cell differentiation.

    PubMed

    Cheng, Jung-Chien; Chang, Hsun-Ming; Fang, Lanlan; Sun, Ying-Pu; Leung, Peter C K

    2015-07-01

    Connexin43 (Cx43)-mediated gap junctional intercellular communication (GJIC) are required for human trophoblast differentiation. To date, whether Cx43 mediates TGF-?1-induced trophoblast differentiation has not been determined. We showed that treatment with TGF-?1 increased Cx43 expression and GJIC in HTR-8/SVneo human trophoblast cells. In addition, Smad and ERK1/2 signaling pathways were involved in TGF-?1-induced up-regulation of Cx43. Moreover, TGF-?1 increased the expression of the syncytiotrophoblast marker, ?-hCG. Importantly, knockdown of Cx43 abolished the TGF-?1-induced up-regulation of ?-hCG. Furthermore, overexpression of Cx43 up-regulated ?-hCG expression. These results provide evidence that Cx43 and GJIC activity are up-regulated by TGF-?1 in human trophoblast cells, which subsequently contributes to TGF-?1-induced trophoblast differentiation. J. Cell. Physiol. 230: 1558-1566, 2015. © 2015 Wiley Periodicals, Inc., A Wiley Company. PMID:25560303

  20. Methamphetamine-Induced Degeneration of Dopaminergic Neurons Involves Autophagy and Upregulation of

    E-print Network

    Sulzer, David

    Methamphetamine-Induced Degeneration of Dopaminergic Neurons Involves Autophagy and Upregulation and Physiology, University of California, San Francisco, California 94143 Methamphetamine (METH) selectively cellular pathway that is activated when DA cannot be effectively sequestered in synaptic vesicles, thereby

  1. Dysregulation of catalase activity in newborn myocytes during hypoxia is mediated by c-Abl tyrosine kinase.

    PubMed

    Cabigas, E Bernadette; Liu, Jie; Boopathy, Archana V; Che, Pao Lin; Crawford, Brian H; Baroi, Gitangali; Bhutani, Srishti; Shen, Ming; Wagner, Mary B; Davis, Michael E

    2015-01-01

    In the adult heart, catalase (CAT) activity increases appropriately with increasing levels of hydrogen peroxide, conferring cardioprotection. This mechanism is absent in the newborn for unknown reasons. In the present study, we examined how the posttranslational modification of CAT contributes to its activation during hypoxia/ischemia and the role of c-Abl tyrosine kinase in this process. Hypoxia studies were carried out using primary cardiomyocytes from adult (>8 weeks) and newborn rats. Following hypoxia, the ratio of phosphorylated to total CAT and c-Abl in isolated newborn rat myocytes did not increase and were significantly lower (1.3- and 4.2-fold, respectively; P < .05) than their adult counterparts. Similarly, there was a significant association (P < .0005) between c-Abl and CAT in adult cells following hypoxia (30.9 ± 8.2 to 70.7 ± 13.1 au) that was absent in newborn myocytes. Although ubiquitination of CAT was higher in newborns compared to adults following hypoxia, inhibition of this did not improve CAT activity. When a c-Abl activator (5-(1,3-diaryl-1H-pyrazol-4-yl)hydantoin [DPH], 200 µmol/L) was administered prior to hypoxia, not only CAT activity was significantly increased (P < .05) but also phosphorylation levels were also significantly improved (P < .01) in these newborn myocytes. Additionally, ischemia-reperfusion (IR) studies were performed using newborn (4-5 days) rabbit hearts perfused in a Langendorff method. The DPH given as an intracardiac injection into the right ventricle of newborn rabbit resulted in a significant improvement (P < .002) in the recovery of developed pressure after IR, a key indicator of cardiac function (from 74.6% ± 6.6% to 118.7% ± 10.9%). In addition, CAT activity was increased 3.92-fold (P < .02) in the same DPH-treated hearts. Addition of DPH to adult rabbits in contrast had no significant effect (from 71.3% ± 10.7% to 59.4% ± 12.1%). Therefore, in the newborn, decreased phosphorylation of CAT by c-Abl potentially mediates IR-induced dysfunction, and activation of c-Abl may be a strategy to prevent ischemic injury associated with surgical procedures. PMID:24831254

  2. Auxins Upregulate Expression of the Indole3Pyruvate Decarboxylase Gene in Azospirillum brasilense

    Microsoft Academic Search

    ANN VANDE BROEK; MARK LAMBRECHT; KRISTEL EGGERMONT; JOS VANDERLEYDEN

    1999-01-01

    Transcription of the Azospirillum brasilense ipdC gene, encoding an indole-3-pyruvate decarboxylase involved in the biosynthesis of indole-3-acetic acid (IAA), is induced by IAA as determined by ipdC-gusA expression studies and Northern analysis. Besides IAA, exogenously added synthetic auxins such as 1-naphthaleneacetic acid, 2,4-dichlorophenoxypropionic acid, and p-chlorophenoxyacetic acid were also found to upregulate ipdC expression. No upregulation was observed with tryptophan,

  3. Up-regulation of Tissue Factor in Human Pulmonary Artery Endothelial Cells after Ultrafine Particle Exposure

    Microsoft Academic Search

    Edward D. Karoly; Zhuowei Li; Lisa A. Dailey; Xhevahire Hyseni; Yuh-Chin T. Huang

    2007-01-01

    RESULTS: We found 320 up-regulated genes and 106 down-regulated genes (p < 0.01, 5% false dis- covery rate). We noted up-regulation of genes related to coagulation (tissue factor (F3) and coagula- tion factor II receptor-like 2 (F2RL2)) and differential regulation of genes related to F3 signaling (FOS, JUN, and NFKBIA). Results of quantitative polymerase chain reaction show a significant up-

  4. Transcriptional upregulation of human tissue kallikrein 6 in ovarian cancer: clinical and mechanistic aspects

    Microsoft Academic Search

    S J C Shan; A Scorilas; D Katsaros; E P Diamandis

    2007-01-01

    The human tissue kallikrein family (KLK for protein; KLK for gene) includes 15 members. Twelve kallikreins, including KLK6, are concurrently upregulated in ovarian cancer. However, the mechanism of this phenomenon remains unclear. In this study, we measured KLK6 expression in a large series of ovarian tissue cytosols and examined possible mechanisms of KLK6 up-regulation in ovarian cancer. Using a newly

  5. Up-regulation of ECT2 is associated with poor prognosisn gastric cancer patients

    PubMed Central

    Jin, Yi; Yu, Yuhui; Shao, Qinshu; Ma, Yingyu; Zhang, Ruxuan; Yao, Haibo; Xu, Yuan

    2014-01-01

    Objectives: The aim of this study was to investigate the expression of ECT2 in gastric cancer and its clinical significance. Methods and results: We investigated the differentially expressed genes between gastric cancer tissues and normal gastric mucosa by cDNA microarray, and then we found ECT2 was up-regulated in gastric cancer. What is more, we verified ECT2 expression level by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and measured its protein level by immunohistochemistry (IHC). qRT-PCR analysis indicated ECT2 was significantly up-regulated in gastric cancer and Immunohistochemistry confirmed the percentage of ECT2-positive specimens was significantly higher in gastric carcinoma than in non-tumor tissues. Up-regulation of ECT2 is associated with the degree of histological differentiation (P = 0.007), invasion depth (P = 0.047), lymph node metastasis (P = 0.016), distant metastasis (P = 0.021) and TNM stage (P = 0.016), patients with up-regulated ECT2 had a lower overall survival rate (P = 0.000). Cox regression analysis revealed that up-regulation of ECT2 is an independent prognostic factor in gastric cancer patients (P = 0.012). Conclusion: Up-regulation of ECT2 might contribute to the progression of gastric carcinogenesis and may be a useful prognostic indicator in gastric cancer. PMID:25674238

  6. Up-regulation of heat shock proteins is essential for cold survival during insect diapause

    PubMed Central

    Rinehart, Joseph P.; Li, Aiqing; Yocum, George D.; Robich, Rebecca M.; Hayward, Scott A. L.; Denlinger, David L.

    2007-01-01

    Diapause, the dormancy common to overwintering insects, evokes a unique pattern of gene expression. In the flesh fly, most, but not all, of the fly's heat shock proteins (Hsps) are up-regulated. The diapause up-regulated Hsps include two members of the Hsp70 family, one member of the Hsp60 family (TCP-1), at least four members of the small Hsp family, and a small Hsp pseudogene. Expression of an Hsp70 cognate, Hsc70, is uninfluenced by diapause, and Hsp90 is actually down-regulated during diapause, thus diapause differs from common stress responses that elicit synchronous up-regulation of all Hsps. Up-regulation of the Hsps begins at the onset of diapause, persists throughout the overwintering period, and ceases within hours after the fly receives the signal to reinitiate development. The up-regulation of Hsps appears to be common to diapause in species representing diverse insect orders including Diptera, Lepidoptera, Coleoptera, and Hymenoptera as well as in diapauses that occur in different developmental stages (embryo, larva, pupa, adult). Suppressing expression of Hsp23 and Hsp70 in flies by using RNAi did not alter the decision to enter diapause or the duration of diapause, but it had a profound effect on the pupa's ability to survive low temperatures. We thus propose that up-regulation of Hsps during diapause is a major factor contributing to cold-hardiness of overwintering insects. PMID:17522254

  7. Transcriptional Regulation of the CmeABC Multidrug Efflux Pump and the KatA Catalase by CosR in Campylobacter jejuni

    PubMed Central

    Hwang, Sunyoung; Zhang, Qijing; Ryu, Sangryeol

    2012-01-01

    CosR is an essential response regulator in Campylobacter jejuni, a major food-borne pathogen causing enteritis worldwide. A transcriptomic analysis performed in this study discovered 93 genes whose transcriptional levels were changed >2-fold due to the repression of CosR expression by antisense peptide nucleic acid. The identified CosR-regulated genes are involved in various cellular functions, such as energy production, protein synthesis and folding, flagellum biogenesis, and lipid metabolism. Interestingly, 17 of the 93 CosR-regulated genes (18.3%) are predicted essential genes, indicating that CosR may participate in the regulation of vital biological processes in C. jejuni. In particular, CosR knockdown increased the transcriptional levels of cmeA, cmeB, and cmeC genes, whose protein product (CmeABC) is an important determinant conferring multidrug resistance in Campylobacter. Negative regulation of cmeABC by CosR was verified by quantitative real-time PCR (qRT-PCR) and PcmeABC::lacZ assay. The results of electrophoretic mobility shift assays (EMSAs) and DNase I footprinting assays demonstrated that CosR directly binds to the cmeABC promoter. Another notable finding is that CosR regulates the transcription of katA, the sole catalase gene in C. jejuni. Further characterization with qRT-PCR, the catalase enzyme assay, EMSA, and DNase I footprinting assays successfully demonstrated that CosR affects the katA transcription and the catalase activity by direct interactions with the katA promoter. The findings in this study clearly demonstrated that CosR regulates resistance mechanisms in C. jejuni by controlling the expression of genes involved in oxidative stress defense and extrusion of toxic compounds out of the cell. PMID:23065977

  8. Immobilization of catalase on electrospun PVA/PA6-Cu(II) nanofibrous membrane for the development of efficient and reusable enzyme membrane reactor.

    PubMed

    Feng, Quan; Zhao, Yong; Wei, Anfang; Li, Changlong; Wei, Qufu; Fong, Hao

    2014-09-01

    In this study, a mat/membrane consisting of overlaid PVA/PA6-Cu(II) composite nanofibers was prepared via the electrospinning technique followed by coordination/chelation with Cu(II) ions; an enzyme of catalase (CAT) was then immobilized onto the PVA/PA6-Cu(II) nanofibrous membrane. The amount of immobilized catalase reached a high value of 64 ± 4.6 mg/g, while the kinetic parameters (Vmax and Km) of enzyme were 3774 ?mol/mg·min and 41.13 mM, respectively. Furthermore, the thermal stability and storage stability of immobilized catalase were improved significantly. Thereafter, a plug-flow type of immobilized enzyme membrane reactor (IEMR) was assembled from the PVA/PA6-Cu(II)-CAT membrane. With the increase of operational pressure from 0.02 to 0.2 MPa, the flux value of IEMR increased from 0.20 ± 0.02 to 0.76 ± 0.04 L/m(2)·min, whereas the conversion ratio of H2O2 decreased slightly from 92 ± 2.5% to 87 ± 2.1%. After 5 repeating cycles, the production capacity of IEMR was merely decreased from 0.144 ± 0.006 to 0.102 ± 0.004 mol/m(2)·min. These results indicated that the assembled IEMR possessed high productivity and excellent reusability, suggesting that the IEMR based on electrospun PVA/PA6-Cu(II) nanofibrous membrane might have great potential for various applications, particularly those related to environmental protection. PMID:25093534

  9. Tobacco smoking, fruit and vegetable intake modify association between -21A>T polymorphism of catalase gene and risk of bronchial asthma.

    PubMed

    Polonikov, A V; Ivanov, V P; Solodilova, M A; Kozhuhov, M A; Panfilov, V I

    2009-04-01

    Although oxidative stress is a cardinal feature of bronchial asthma, the role of interactions between environmental oxidant/antioxidant exposures and antioxidant genes in asthma aetiology has yet to be determined. The present study was conducted to investigate whether two common polymorphisms -21A > T and -262C > T of catalase (CAT) gene are associated with susceptibility to asthma in a Russian population and to test the hypothesis that the asthma risk attributed to CAT genotypes could be dependent on both oxidant (tobacco smoking) and antioxidant (fruit and vegetable intake) exposures. A total of 429 unrelated Russian individuals from Central Russia were recruited in the study, including 215 asthmatics and 214 sex- and age-matched healthy controls. Genotyping analysis for the CAT gene polymorphisms was performed by PCR-RFLP assays. The frequencies of both allele -21A (OR 0.73 95%CI 0.55-0.96 p = 0.03) and -21AA CAT genotype (OR 0.42 95%CI 0.23-0.76 p = 0.004) were higher among asthmatics than among healthy controls. The frequency of -21AA genotype of the CAT gene was significantly higher in patients with allergic (OR 0.47 95%CI 0.25-0.92 p = 0.024) and nonallergic (OR 0.32 95%CI 0.14-0.71 p = 0.004) asthma in comparison with controls (at the Bonferroni corrected p value less than 0.025). Polymorphisms -21A > T and -262C > T of the catalase gene were in a positive linkage disequilibrium (p < 0.0001). Smokers who carried -21AA genotype had an increased risk of nonallergic asthma (p = 0.002), whereas nonsmoker carriers of this genotype did not have the risk of any variant of the disease. Notably, no association of CAT genotype -21AA with asthma was found in high fruit and vegetable consumers, whereas low fruit and vegetable consumers (one time per day or less often) possessing this genotype were at increased risk of both allergic (p = 0.013) and nonallergic (p = 0.008) asthma. This is the first study reporting an association of polymorphism -21A > T of the catalase gene with allergic and nonallergic asthma. We also found, for the first time, that cigarette smoking and fruit and vegetable intakes have potentially inverse modifying influences on the asthma risk in individuals with -21AA CAT genotype and that the gene-environment interactions that were found support the biologic plausibility of catalase gene for the development of bronchial asthma. PMID:19373626

  10. Exogenous proline and glycine betaine mediated upregulation of antioxidant defense and glyoxalase systems provides better protection against salt-induced oxidative stress in two rice (Oryza sativa L.) varieties.

    PubMed

    Hasanuzzaman, Mirza; Alam, Md Mahabub; Rahman, Anisur; Hasanuzzaman, Md; Nahar, Kamrun; Fujita, Masayuki

    2014-01-01

    The present study investigates the roles of exogenous proline (Pro, 5?mM) and glycine betaine (GB, 5?mM) in improving salt stress tolerance in salt sensitive (BRRI dhan49) and salt tolerant (BRRI dhan54) rice (Oryza sativa L.) varieties. Salt stresses (150 and 300?mM NaCl for 48?h) significantly reduced leaf relative water (RWC) and chlorophyll (chl) content and increased endogenous Pro and increased lipid peroxidation and H2O2 levels. Ascorbate (AsA), glutathione (GSH) and GSH/GSSG, ascorbate peroxidae (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), catalase (CAT), and glyoxalase I (Gly I) activities were reduced in sensitive variety and these were increased in tolerant variety due to salt stress. The glyoxalase II (Gly II), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities were increased in both cultivars by salt stress. Exogenous Pro and GB application with salt stress improved physiological parameters and reduced oxidative damage in both cultivars where BRRI dhan54 showed better tolerance. The result suggests that exogenous application of Pro and GB increased rice seedlings' tolerance to salt-induced oxidative damage by upregulating their antioxidant defense system where these protectants rendered better performance to BRRI dhan54 and Pro can be considered as better protectant than GB. PMID:24991566

  11. Exogenous Proline and Glycine Betaine Mediated Upregulation of Antioxidant Defense and Glyoxalase Systems Provides Better Protection against Salt-Induced Oxidative Stress in Two Rice (Oryza sativa L.) Varieties

    PubMed Central

    Hasanuzzaman, Mirza; Alam, Md. Mahabub; Rahman, Anisur; Hasanuzzaman, Md.; Nahar, Kamrun; Fujita, Masayuki

    2014-01-01

    The present study investigates the roles of exogenous proline (Pro, 5?mM) and glycine betaine (GB, 5?mM) in improving salt stress tolerance in salt sensitive (BRRI dhan49) and salt tolerant (BRRI dhan54) rice (Oryza sativa L.) varieties. Salt stresses (150 and 300?mM NaCl for 48?h) significantly reduced leaf relative water (RWC) and chlorophyll (chl) content and increased endogenous Pro and increased lipid peroxidation and H2O2 levels. Ascorbate (AsA), glutathione (GSH) and GSH/GSSG, ascorbate peroxidae (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), catalase (CAT), and glyoxalase I (Gly I) activities were reduced in sensitive variety and these were increased in tolerant variety due to salt stress. The glyoxalase II (Gly II), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities were increased in both cultivars by salt stress. Exogenous Pro and GB application with salt stress improved physiological parameters and reduced oxidative damage in both cultivars where BRRI dhan54 showed better tolerance. The result suggests that exogenous application of Pro and GB increased rice seedlings' tolerance to salt-induced oxidative damage by upregulating their antioxidant defense system where these protectants rendered better performance to BRRI dhan54 and Pro can be considered as better protectant than GB. PMID:24991566

  12. Rapid identification of a point mutation of the Mycobacterium tuberculosis catalase-peroxidase (katG) gene associated with isoniazid resistance.

    PubMed

    Cockerill, F R; Uhl, J R; Temesgen, Z; Zhang, Y; Stockman, L; Roberts, G D; Williams, D L; Kline, B C

    1995-01-01

    The complete catalase-peroxidase (katG) gene DNA sequence was determined for 15 strains of Mycobacterium tuberculosis with a wide range of susceptibility to isoniazid. Five of 9 strains with isoniazid MICs > or = 1.0 microgram/mL had one or more missense mutations and all 5 strains had a common G-->T transversion in codon 463, causing the replacement of arginine with leucine and the loss of an NciI or MspI restriction site. None of 6 strains with an isoniazid MIC < 1.0 microgram/mL had mutations affecting codon 463. Restriction analysis of 43 strains with isoniazid MICs > or = 1.0 microgram/mL showed that 19 (44.2%) had lost the NciI-MspI restriction site at the locus of codon 463 while only 1 of 32 strains with isoniazid MICs < or = 1.0 microgram/L had this restriction polymorphism. These results indicate that the mutation arginine-->leucine in codon 463 of the catalase-peroxidase gene occurs in a significant fraction (44.2%) of M. tuberculosis strains with isoniazid MICs > or = 1.0 microgram/mL. PMID:7798673

  13. Degradation of direct yellow 9 by electro-Fenton: process study and optimization and, monitoring of treated water toxicity using catalase.

    PubMed

    Kourdali, Sidali; Badis, Abdelmalek; Boucherit, Ahmed

    2014-12-01

    The present study was undertaken to investigate the degradation and removal of direct yellow 9 (DY9) by the electro-Fenton (EF) process in batch reactor using iron and stainless steel electrodes. DY9 removal decreased with the increase in pH (3 to 8) and increased with the increase in current intensity (0.05 to 0.2A) and [H2O2] (0 to 0.5gL(-1), but not with high doses which led to low rates of DY9 removal and OH(?) uptake). The regression quadratic models describing DY9 degradation yield "R (percent)" and electrical energy consumption "EEC (kWhkg(-1))" were validated by the analysis of variance (ANOVA) and were both noted to fit well with the experimental data. The R(2) correlation coefficients (0.995, 0.978), those adjusted coefficients (0.986, 0.939), and F values (110.7, 24.9) obtained for the responses validated the efficiency of model. The results revealed that among several other parameters, EEC depended essentially on the degradation yield. The eco-toxicity tests showed a positive correlation between catalase activity and DY9 concentration, and catalase could be qualitatively identified to assess the effect of dye and its by-products generated during the EF process. PMID:25216029

  14. Peroxiredoxin-glutaredoxin and catalase promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidants and survival within neutrophil extracellular traps.

    PubMed

    Juneau, Richard A; Pang, Bing; Armbruster, Chelsie E; Murrah, Kyle A; Perez, Antonia C; Swords, W Edward

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHI) is a common commensal and opportunistic pathogen of the human airways. For example, NTHI is a leading cause of otitis media and is the most common cause of airway infections associated with chronic obstructive pulmonary disease (COPD). These infections are often chronic/recurrent in nature and involve bacterial persistence within biofilm communities that are highly resistant to host clearance. Our previous work has shown that NTHI within biofilms has increased expression of factors associated with oxidative stress responses. The goal of this study was to define the roles of catalase (encoded by hktE) and a bifunctional peroxiredoxin-glutaredoxin (encoded by pdgX) in resistance of NTHI to oxidants and persistence in vivo. Isogenic NTHI strain 86-028NP mutants lacking hktE and pdgX had increased susceptibility to peroxide. Moreover, these strains had persistence defects in the chinchilla infection model for otitis media, as well as in a murine model for COPD. Additional work showed that pdgX and hktE were important determinants of NTHI survival within neutrophil extracellular traps (NETs), which we have shown to be an integral part of NTHI biofilms in vivo. Based on these data, we conclude that catalase and peroxiredoxin-glutaredoxin are determinants of bacterial persistence during chronic/recurrent NTHI infections that promote bacterial survival within NETs. PMID:25348637

  15. Fluctuations in peroxidase and catalase activities of resistant and susceptible black gram (Vigna mungo (L.) Hepper) genotypes elicited by Bemisia tabaci (Gennadius) feeding

    PubMed Central

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Sandhu, Jeet Singh

    2012-01-01

    Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae), is a serious pest of black gram, (Vigna mungo (L.) Hepper), an important legume pulse crop grown in north India. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to whitefly in nine black gram genotypes. Oxidative enzyme activity was estimated spectrophotometrically from leaf samples collected at 30 and 50 d after sowing (DAS) from whitefly infested and uninfested plants. The enzymes showed different activity levels at different times after the infestation. The results indicated that in general, whitefly infestation increased the activities of peroxidase and decreased the catalase activity. Resistant genotypes NDU 5-7 and KU 99-20 recorded higher peroxidase and catalase activities at 30 and 50 DAS under whitefly-stress conditions as compared with non-stressed plants. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of black gram plants against B. tabaci infestation. The potential mechanisms to explain the correlation of resistance to whitefly in black gram genotypes with higher activities of oxidative enzymes are also discussed. PMID:22902801

  16. TGF-? modulates ovarian cancer invasion by upregulating CAF-derived versican in the tumor microenvironment

    PubMed Central

    Yeung, Tsz-Lun; Leung, Cecilia S.; Wong, Kwong-Kwok; Samimi, Goli; Thompson, Melissa S.; Liu, Jinsong; Zaid, Tarrik M.; Ghosh, Sue; Birrer, Michael J.; Mok, Samuel C.

    2013-01-01

    TGF-? has limited effects on ovarian cancer cells but its contributions to ovarian tumor growth might be mediated through elements of the tumor microenvironment. In the present study, we tested the hypothesis that TGF- modulates ovarian cancer progression by modulating the contribution of cancer-associated fibroblasts (CAFs) that are present in the microenvironment. Transcriptome profiling of microdissected stromal and epithelial components of high-grade serous ovarian tumors and TGF-?-treated normal ovarian fibroblasts identified versican (VCAN) as a key upregulated target gene in CAFs. Functional evaluations in co-culture experiments demonstrated that TGF-? enhanced the aggressiveness of ovarian cancer cells by upregulating VCAN in CAFs. VCAN expression was regulated in CAFs through TGF-? receptor type II and SMAD signaling. Upregulated VCAN promoted the motility and invasion of ovarian cancer cells by activating the NF-?B signaling pathway and by upregulating expression of CD44, MMP9, and the hyaluronan-mediated motility receptor (HMMR). Our work identified a TGF-?-inducible gene signature specific to CAFs in advanced high-grade serous ovarian tumors, and showed how TGF-? stimulates ovarian cancer cell motility and invasion by upregulating the CAF-specific gene VCAN. These findings suggest insights to develop or refine strategies for TGF-?-targeted therapy of ovarian cancer. PMID:23824740

  17. Hypoxia up-regulates SERPINB3 through HIF-2? in human liver cancer cells

    PubMed Central

    Paternostro, Claudia; Biasiolo, Alessandra; Colombatto, Sebastiano; Cambieri, Irene; Quarta, Santina; Novo, Erica; Morello, Elisabetta; Villano, Gianmarco; Fasolato, Silvano; Musso, Tiziana; David, Ezio; Tusa, Ignazia; Rovida, Elisabetta; Autelli, Riccardo; Smedile, Antonina; Cillo, Umberto; Pontisso, Patrizia; Parola, Maurizio

    2015-01-01

    SERPINB3 is a cysteine-proteases inhibitor up-regulated in a significant number of cirrhotic patients carrying hepatocellular carcinoma (HCC) and recently proposed as a prognostic marker for HCC early recurrence. SERPINB3 has been reported to stimulate proliferation, inhibit apoptosis and, similar to what reported for hypoxia, to trigger epithelial-to-mesenchymal transition (EMT) and increased invasiveness in liver cancer cells. This study has investigated whether SERPINB3 expression is regulated by hypoxia-related mechanisms in liver cancer cells. Exposure of HepG2 and Huh7 cells to hypoxia up-regulated SERPINB3 transcription, protein synthesis and release in the extracellular medium. Hypoxia-dependent SERPINB3 up-regulation was selective (no change detected for SERPINB4) and operated through hypoxia inducible factor (HIF)-2? (not HIF-1?) binding to SERPINB3 promoter, as confirmed by chromatin immuno-precipitation assay and silencing experiments employing specific siRNAs. HIF-2?-mediated SERPINB3 up-regulation under hypoxic conditions required intracellular generation of ROS. Immuno-histochemistry (IHC) and transcript analysis, performed in human HCC specimens, revealed co-localization of the two proteins in liver cancer cells and the existence of a positive correlation between HIF-2? and SERPINB3 transcript levels, respectively. Hypoxia, through HIF-2?-dependent and redox-sensitive mechanisms, up-regulates the transcription, synthesis and release of SERPINB3, a molecule with a high oncogenic potential. PMID:25544768

  18. Hypoxia up-regulates SERPINB3 through HIF-2? in human liver cancer cells.

    PubMed

    Cannito, Stefania; Turato, Cristian; Paternostro, Claudia; Biasiolo, Alessandra; Colombatto, Sebastiano; Cambieri, Irene; Quarta, Santina; Novo, Erica; Morello, Elisabetta; Villano, Gianmarco; Fasolato, Silvano; Musso, Tiziana; David, Ezio; Tusa, Ignazia; Rovida, Elisabetta; Autelli, Riccardo; Smedile, Antonina; Cillo, Umberto; Pontisso, Patrizia; Parola, Maurizio

    2015-02-10

    SERPINB3 is a cysteine-proteases inhibitor up-regulated in a significant number of cirrhotic patients carrying hepatocellular carcinoma (HCC) and recently proposed as a prognostic marker for HCC early recurrence. SERPINB3 has been reported to stimulate proliferation, inhibit apoptosis and, similar to what reported for hypoxia, to trigger epithelial-to-mesenchymal transition (EMT) and increased invasiveness in liver cancer cells. This study has investigated whether SERPINB3 expression is regulated by hypoxia-related mechanisms in liver cancer cells. Exposure of HepG2 and Huh7 cells to hypoxia up-regulated SERPINB3 transcription, protein synthesis and release in the extracellular medium. Hypoxia-dependent SERPINB3 up-regulation was selective (no change detected for SERPINB4) and operated through hypoxia inducible factor (HIF)-2? (not HIF-1?) binding to SERPINB3 promoter, as confirmed by chromatin immuno-precipitation assay and silencing experiments employing specific siRNAs. HIF-2?-mediated SERPINB3 up-regulation under hypoxic conditions required intracellular generation of ROS. Immuno-histochemistry (IHC) and transcript analysis, performed in human HCC specimens, revealed co-localization of the two proteins in liver cancer cells and the existence of a positive correlation between HIF-2? and SERPINB3 transcript levels, respectively. Hypoxia, through HIF-2?-dependent and redox-sensitive mechanisms, up-regulates the transcription, synthesis and release of SERPINB3, a molecule with a high oncogenic potential. PMID:25544768

  19. Upregulation of heme oxygenase-1 by degranulation in rat basophilic leukemia cells.

    PubMed

    Yasui, Yumiko; Sasao, Emiko; Sakata, Masaru; Matsui, Nobuaki; Fukuishi, Nobuyuki; Akagi, Reiko; Akagi, Masaaki

    2007-03-01

    Heme oxygenase (HO)-1, which is a rate-limiting enzyme involved in the catabolism of heme, is upregulated by a variety of stresses including oxidative stresses and inflammatory cytokines, in many cell types. Recent studies have suggested that upregulation of HO-1 might provide cytoprotection and immunomodulatory functions in addition to its obvious role in heme metabolism. In this study, we examined whether HO-1 was upregulated following degranulation in mast cells that initiate vigorous immunity reactions. To trigger degranulation, rat basophilic leukemia (RBL)-2H3 cells were passively sensitized using an antiserum collected from ovalbumin (OA) immunized-Brown Norway rats, and the cells were stimulated by treatment with OA. Degranulation was confirmed by measuring the release of beta-hexosaminidase. HO-1 mRNA and presence of HO-1 protein were detected using Northern blot and Western blot analyses, respectively. The effect of the antioxidant N-acetyl-L-cysteine (NAC) on HO-1 expression was also tested. HO-1 mRNA transiently increased at 1--2 h after RBL-2H3 cells were stimulated to degranulate. Its mRNA increases were dependent on the extent of degranulation. Following the upregulation of HO-1 mRNA, HO-1 protein was also increased. We also detected intracellular production of reactive oxygen species following degranulation in RBL-2H3 cells. NAC attenuated the HO-1 expression in a dose-dependent manner. This is the first report to reveal induction of both HO-1 mRNA and protein by degranulation in RBL-2H3 cells. We showed that NAC inhibited HO-1 upregulation. These results suggest that oxidative stress in activated RBL-2H3 cells results in the upregulation of HO-1. PMID:17329835

  20. Mu opioid receptor up-regulation and participation in excitability of hippocampal pyramidal cell electrophysiology

    SciTech Connect

    Moudy, A.M.

    1988-01-01

    Chronic administration of opiate antagonists to rats results in up-regulation of their brain opioid receptors. Using subcellular fractionation techniques, brain opioid receptors were resolved into two membrane populations, one associated with synaptic plasma membranes (SPM) and the other enriched in smooth endoplasmic reticulum and Golgi (microsomes). This study addressed in part the question of whether an antagonist induces up-regulation uniformly in these two populations. Rats were administered naltrexone by subcutaneously implanted osmotic minipumps. Forebrain mu receptor levels were determined by homologous displacement of ({sup 3}H)D-ala{sup 2}-mePhe{sup 4}-gly-ol{sup 5}-enkephalin (DAGO) followed by computer estimation of binding parameters. Receptor levels in crude membranes rose 77% after treatment. Microsomes displayed a 92% increase, a two-fold greater change than in SPMs (51%). These results establish that naltrexone induces up-regulation of both membrane populations; and that microsomal and SPM receptors represent discrete populations of intracellular and cell surface sites, respectively. Binding experiments on isolated hippocampi also demonstrated up-regulation (71%) of mu receptors. To demonstrate up-regulation of opioid receptors electrophysiologically, hippocampal slices were prepared from rats which had been chronically treated with naltrexone. After superfusion with DAGO, these slices showed a 42% greater population spike output than controls in response to the same EPSP input. Hippocampi from animals treated for two weeks showed an additional increase in sensitivity. The results support a disinhibitory role for opioids in pyramidal cell hyper-excitability. More importantly, they demonstrate a significant physiological correlate to opioid receptor up-regulation.

  1. Early events triggering delayed vasoconstrictor receptor upregulation and cerebral ischemia after subarachnoid hemorrhage

    PubMed Central

    2013-01-01

    Background Upregulation of vasoconstrictor receptors in cerebral arteries, including endothelin B (ETB) and 5-hydroxytryptamine 1B (5-HT1B) receptors, has been suggested to contribute to delayed cerebral ischemia, a feared complication after subarachnoid hemorrhage (SAH). This receptor upregulation has been shown to be mediated by intracellular signalling via the mitogen activated protein kinase kinase (MEK1/2) - extracellular regulated kinase 1/2 (ERK1/2) pathway. However, it is not known what event(s) that trigger MEK-ERK1/2 activation and vasoconstrictor receptor upregulation after SAH. We hypothesise that the drop in cerebral blood flow (CBF) and wall tension experienced by cerebral arteries in acute SAH is a key triggering event. We here investigate the importance of the duration of this acute CBF drop in a rat SAH model in which a fixed amount of blood is injected into the prechiasmatic cistern either at a high rate resulting in a short acute CBF drop or at a slower rate resulting in a prolonged acute CBF drop. Results We demonstrate that the duration of the acute CBF drop is determining for a) degree of early ERK1/2 activation in cerebral arteries, b) delayed upregulation of vasoconstrictor receptors in cerebral arteries and c) delayed CBF reduction, neurological deficits and mortality. Moreover, treatment with an inhibitor of MEK-ERK1/2 signalling during an early time window from 6 to 24 h after SAH was sufficient to completely prevent delayed vasoconstrictor receptor upregulation and improve neurological outcome several days after the SAH. Conclusions Our findings suggest a series of events where 1) the acute CBF drop triggers early MEK-ERK1/2 activation, which 2) triggers the transcriptional upregulation of vasoconstrictor receptors in cerebral arteries during the following days, where 3) the resulting enhanced cerebrovascular contractility contribute to delayed cerebral ischemia. PMID:23496889

  2. Pim kinases are upregulated during Epstein-Barr virus infection and enhance EBNA2 activity

    SciTech Connect

    Rainio, Eeva-Marja [Turku Centre for Biotechnology, University of Turku/Abo Akademi University, Tykistoekatu 6B, 20520 Turku (Finland); Turku Graduate School of Biomedical Sciences, 20520 Turku (Finland); Ahlfors, Helena [Turku Centre for Biotechnology, University of Turku/Abo Akademi University, Tykistoekatu 6B, 20520 Turku (Finland); Carter, Kara L. [Department of Medicine and Microbiology, Harvard Medical School, Boston, MA 02115 (United States); Department of Molecular Genetics, Harvard Medical School, Boston, MA 02115 (United States); Channing Laboratory, Brigham and Women's Hospital, Boston, MA 02115 (United States); Ruuska, Marja [Turku Centre for Biotechnology, University of Turku/Abo Akademi University, Tykistoekatu 6B, 20520 Turku (Finland); Matikainen, Sampsa [Turku Centre for Biotechnology, University of Turku/Abo Akademi University, Tykistoekatu 6B, 20520 Turku (Finland); Department of Microbiology, National Public Health Institute, Mannerheimintie 166, 00300 Helsinki (Finland); Kieff, Elliott [Department of Medicine and Microbiology, Harvard Medical School, Boston, MA 02115 (United States); Department of Molecular Genetics, Harvard Medical School, Boston, MA 02115 (United States); Channing Laboratory, Brigham and Women's Hospital, Boston, MA 02115 (United States); Koskinen, Paeivi J. [Turku Centre for Biotechnology, University of Turku/Abo Akademi University, Tykistoekatu 6B, 20520 Turku (Finland)]. E-mail: paivi.koskinen@btk.fi

    2005-03-15

    Latent Epstein-Barr virus (EBV) infection is strongly associated with B-cell proliferative diseases such as Burkitt's lymphoma. Here we show that the oncogenic serine/threonine kinases Pim-1 and Pim-2 enhance the activity of the viral transcriptional activator EBNA2. During EBV infection of primary B-lymphocytes, the mRNA expression levels of pim genes, especially of pim-2, are upregulated and remain elevated in latently infected B-cell lines. Thus, EBV-induced upregulation of Pim kinases and Pim-stimulated EBNA2 transcriptional activity may contribute to the ability of EBV to immortalize B-cells and predispose them to malignant growth.

  3. Cisplatin upregulates mitochondrial nitric oxide synthase and peroxynitrite formation to promote renal injury

    SciTech Connect

    Jung, Michaela [Department of Ischemia and Inflammation, Instituto de Investigaciones Biomedicas, IIBB-CSIC-IDIBAPS, C/ Rossello, 161, 7a, 08036 Barcelona (Spain); Hotter, Georgina; Vinas, Jose Luis [Department of Ischemia and Inflammation, Instituto de Investigaciones Biomedicas, IIBB-CSIC-IDIBAPS, C/ Rossello, 161, 7a, 08036 Barcelona (Spain); CIBER-BBN, Networking Center on Bioengineering, Biomaterials and Nanomedicine, Barcelona (Spain); Sola, Anna [Department of Ischemia and Inflammation, Instituto de Investigaciones Biomedicas, IIBB-CSIC-IDIBAPS, C/ Rossello, 161, 7a, 08036 Barcelona (Spain); CIBER-BBN, Networking Center on Bioengineering, Biomaterials and Nanomedicine, Barcelona (Spain)], E-mail: asmbam@iibb.csic.es

    2009-01-15

    The mitochondria are a critical target for cisplatin-associated nephrotoxicity. Though nitric oxide formation has been implicated in the toxicity of cisplatin, this formation has not so far been related to a possible activation of mitochondrial nitric oxide synthase (mNOS). We show here that the upregulation of oxide mNOS and peroxynitrite formation in cisplatin treatment are key events that influence the development of the harmful parameters described in cisplatin-associated kidney failure. We confirm this by isolating the mitochondrial fraction of the kidney and across different access routes such as the use of a specific inhibitor of neuronal NOS, L-NPA, a peroxynitrite scavenger, FeTMPyP, and a peroxynitrite donor, SIN-1. The in vitro studies corroborated the information obtained in the in vivo experiments. The administration of cisplatin reveals a clear upregulation in the transcription of neuronal NOS and an increase in the levels of nitrites in the mitochondrial fractions of the kidneys. The upregulated transcription directly affects the cytoskeleton structure and the apoptosis. The inhibition of neuronal NOS reduces the levels of nitrites, cell death, and cytoskeleton derangement. Peroxynitrite is involved in the mechanism promoting the NOS transcription. In addition, in controls SIN-1 imitates the effects of cisplatin. In summary, we demonstrate that upregulation of mNOS in cisplatin treatment is a key component in both the initiation and the spread of cisplatin-associated damage in the kidney. Furthermore, peroxynitrite formation is directly involved in this process.

  4. Upregulation of ERG Genes in Candida Species by Azoles and Other Sterol Biosynthesis Inhibitors

    Microsoft Academic Search

    KARL W. HENRY; JOSEPH T. NICKELS; THOMAS D. EDLIND

    2000-01-01

    Infections due to Candida albicans are usually treated with azole antifungals such as fluconazole, but treat- ment failure is not uncommon especially in immunocompromised individuals. Relatedly, in vitro studies dem- onstrate that azoles are nonfungicidal, with continued growth at strain-dependent rates even at high azole con- centrations. We hypothesized that upregulation of ERG11, which encodes the azole target enzyme lanosterol

  5. Cotton Benzoquinone Reductase: Up-regulation During Early Cotton Fiber Developement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzoquinone reductase (BR; EC 1.6.5.7) is an enzyme that catalyzes the bivalent redox reactions of quinones without the production of free radical intermediates. Using 2-D PAGE comparisons, two proteins were found to be up-regulated in wild-type cotton ovules during the fiber initiation stage but ...

  6. Expression of a GALACTINOL SYNTHASE Gene in Tomato Seeds Is Up-Regulated before Maturation

    E-print Network

    Bradford, Kent

    Expression of a GALACTINOL SYNTHASE Gene in Tomato Seeds Is Up-Regulated before Maturation enzyme in the biosynthesis of RFOs, was cloned from tomato (Lycopersicon esculentum Mill. cv Moneymaker) seeds, and its expression was characterized in tomato seeds and seedlings. GOLS (LeGOLS-1) m

  7. Resistance to anti-xenogeneic response by combining ?-Gal silencing with HO1 upregulation

    Microsoft Academic Search

    Min Zhu; Wei Zhang; Fang Liu; Lu Wang; Bin Liu; Dong Chen; Xue-Hai Zhu; Wei-Jie Zhang; Thomas E. Ichim; Zhi-Shui Chen; Ping Zhou; Shi Chen; Gang Chen

    2008-01-01

    BackgroundA major barrier to clinical xenotransplantation is preformed xenoreactive natural antibodies (XNA) found in higher primates which react to Gal?(1,3)Gal (?-Gal) epitopes found on lower species. Accommodation of organs to xenogeneic recipients involves upregulation of cytoprotective genes and resistance to complement dependent cytotoxicity (CDC).

  8. Upregulation of Twist in oesophageal squamous cell carcinoma is associated with neoplastic transformation and distant metastasis

    Microsoft Academic Search

    Hiu-Fung Yuen; Yuen-Piu Chan; Michelle Lok-Yee Wong; Wei-Kei Kwok; Ka-Kui Chan; Pin-Yin Lee; Gopesh Srivastava; Simon Ying-Kit Law; Yong-Chuan Wong; Xianghong Wang; Kwok-Wah Chan

    2007-01-01

    Background: The antiapoptotic and epithelial–mesenchymal transition activities of Twist have been implicated in the neoplastic transformation and the development of metastasis, respectively. Upregulation of Twist, described in several types of human cancer, also acts as a prognostic marker of poor outcome.Aim: To investigate Twist expression in oesophageal squamous cell carcinoma (SCC) and its prognostic value in a Chinese cohort of

  9. Relationship Between Donor Factors, Immunogenic Up-Regulation, and Outcome After Kidney Transplantation

    Microsoft Academic Search

    E. Nyhof; S. Wiehl; J. Steinhoff; S. Krüger; M. Mueller-Steinhardt; L. Fricke

    2005-01-01

    Epidemiological data show that the cause of brain death as well as the condition of the organ donor have considerable influence on the outcome of kidney transplantation. An early immunogenic up-regulation, which already exists at the time of organ removal seems to be primarily responsible. So far it has remained unclear which donor factors cause this effect. In a prospective

  10. Testosterone is required for corticosteroid-binding globulin upregulation by morphine to be fully manifested

    E-print Network

    Steinbach, Joe Henry

    increases the concentration of corticosteroid-binding globulin (CBG) in blood of male, but not female, rats. This pronounced sexual dimorphism suggested that CBG upregulation by morphine might be androgen or in adulthood, increased the concentration of CBG in adult male rats. Naltrexone did not prevent this increase

  11. AGING UP-REGULATES EXPRESSION OF INFLAMMATORY MEDIATORS IN MOUSE ADIPOSE TISSUE (AT)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The incidence of type 2 diabetes (T2D) increases with age. Low-grade inflammation in AT is implicated in development of insulin resistance and T2D. This study investigated if inflammatory responses are up-regulated with age in AT. Results showed that visceral AT from old mice have higher mRNA expres...

  12. Ischemic Preconditioning of Renal Tissue: Identification of Early Up-Regulated Genes

    Microsoft Academic Search

    Marcelo Damario Gomes; Douglas Vasconcelos Cancherini; Marise Amaral Rebouças Moreira; Nancy Amaral Rebouças

    2003-01-01

    Given the important effects of ischemic preconditioning (IPC) in minimizing tissue damage induced by sustained ischemia in several tissues, this study evaluated the effect of IPC in preserving renal function and identified up-regulated genes after 30 min of preconditioning. IPC induced by 2, 3 and 4 min of ischemia, intercalated by 5 min of reperfusion, induced a measurable protection of

  13. CD84 is markedly up-regulated in Kawasaki disease arteriopathy.

    PubMed

    Reindel, R; Bischof, J; Kim, K-Y A; Orenstein, J M; Soares, M B; Baker, S C; Shulman, S T; Perlman, E J; Lingen, M W; Pink, A J; Trevenen, C; Rowley, A H

    2014-07-01

    The major goals of Kawasaki disease (KD) therapy are to reduce inflammation and prevent thrombosis in the coronary arteries (CA), but some children do not respond to currently available non-specific therapies. New treatments have been difficult to develop because the molecular pathogenesis is unknown. In order to identify dysregulated gene expression in KD CA, we performed high-throughput RNA sequencing on KD and control CA, validated potentially dysregulated genes by real-time reverse transcription-polymerase chain reaction (RT-PCR) and localized protein expression by immunohistochemistry. Signalling lymphocyte activation molecule CD84 was up-regulated 16-fold (P?up-regulated in KD CA, and immune activation molecules MX2 and SP140 were up-regulated in chronic KD. CD84, which facilitates immune responses and stabilizes platelet aggregates, is markedly up-regulated in KD CA in patients with acute and chronic arterial disease. We provide the first molecular evidence of dysregulated inflammatory responses persisting for months to years in CA significantly damaged by KD. PMID:24635044

  14. Sex differences in immunity and rapid upregulation of immune defence during parental care in the burying

    E-print Network

    Sakaluk, Scott

    insect immunity. 2. Burying beetles provide extensive biparental care that includes the burialSex differences in immunity and rapid upregulation of immune defence during parental care in the burying beetle, Nicrophorus orbicollis Sandra Steiger*, Susan N. Gershman , Adam M. Pettinger, Anne

  15. Upregulation of cathepsin S in psoriatic keratinocytes Alexander Scho nefu1

    E-print Network

    Lübbert, Hermann

    skin biopsies, i.e. atopic dermatitis, actinic keratosis and psoriasis, CATS staining is strongly increased in the dermis. But only in psoriasis, CATS- immunostaining is also detectable in keratinocytes. We ­ psoriasis ­ T-cell Please cite this paper as: Upregulation of cathepsin S in psoriatic keratinocytes

  16. Upregulated expression of vascular endothelial growth factor in proliferative diabetic retinopathy

    Microsoft Academic Search

    J Peer; R Folberg; A Itin; H Gnessin; I Hemo; E Keshet

    1996-01-01

    AIMS\\/BACKGROUND: Vascular endothelial growth factor (VEGF) is a hypoxia induced angiogenic factor. Recent studies have shown that high levels of VEGF accumulate in the vitreous of patients with proliferative diabetic retinopathy (PDR). The purpose of the present study was to identify the retinal cells that upregulate VEGF expression in human PDR patients representing progressive stages of retina deterioration. METHODS: Thirteen

  17. Executive functions and the down-regulation and up-regulation of emotion

    PubMed Central

    Gyurak, Anett; Goodkind, Madeleine S.; Kramer, Joel H.; Miller, Bruce L.; Levenson, Robert W.

    2011-01-01

    This study examined the relationship between individual differences in executive functions (EF; assessed by measures of working memory, Stroop, trail making, and verbal fluency) and ability to down-regulate and up-regulate responses to emotionally evocative film clips. To ensure a wide range of EF, 48 participants with diverse neurodegenerative disorders and 21 older neurologically normal aging participants were included. Participants were exposed to three different movie clips that were designed to elicit a mix of disgust and amusement. While watching the films they were either instructed to watch, down-regulate, and up-regulate their visible emotional responses. Heart-rate and facial behaviors were monitored throughout. Emotion regulatory ability was operationalized as changes in heart-rate and facial behavior in the down- and up-regulation conditions, controlling for responses in the watch condition. Results indicated that higher verbal fluency scores were related to greater ability to regulate emotion in both the down-regulation and up-regulation conditions. This finding remained significant even after controlling for age and general cognitive functioning. No relationships were found between emotion regulation and the other EF measures. We believe these results derive from differences among EF measures, with verbal fluency performance best capturing the complex sequence of controlled planning, activation, and monitoring required for successful emotion regulation. These findings contribute to our understanding of emotion-cognition interaction, suggesting a link between emotion-regulatory abilities and individual differences in complex executive functions. PMID:21432634

  18. Medroxyprogesterone Acetate Antagonizes Estrogen Up-Regulation of Brain Mitochondrial Function

    E-print Network

    Brinton, Roberta Diaz

    Medroxyprogesterone Acetate Antagonizes Estrogen Up-Regulation of Brain Mitochondrial Function progestin, medroxyprogesterone acetate (MPA), on glycolysis, oxidative stress, and mitochondrial function calcium homeostasis and increased oxidative stress ISSN Print 0013-7227 ISSN Online 1945-7170 Printed in U

  19. Effect of Yerbimat herbicide on lipid peroxidation, catalase activity, and histological damage in gills and liver of the freshwater fish Goodea atripinnis.

    PubMed

    Ortiz-Ordoñez, Esperanza; Uría-Galicia, Esther; Ruiz-Picos, Ricardo Arturo; Duran, Angela Georgina Sánchez; Trejo, Yoseline Hernández; Sedeño-Díaz, Jacinto Elías; López-López, Eugenia

    2011-10-01

    The use of herbicides for agricultural and aquatic weed control has increased worldwide. These substances are potentially toxic pollutants because they induce the production of reactive oxygen species for biological systems and exert oxidative stress in nontarget organisms living in the treated aquatic systems. Recent evidence suggests differences in the toxicity of glyphosate in the form of an active ingredient compared to the toxicity of glyphosate in combination with surfactants, such as those found in commercial formulations. In Mexico, one of the most widely used glyphosate-based herbicides is Yerbimat, which has agricultural as well as aquatic weed control applications. However, there are no aquatic toxicity data, particularly regarding native fish. Therefore, we determined the acute toxicity of commercial-formulation Yerbimat in a static bioassay at 96 h (LC(50)). We also determined its toxicity at 96 h in sublethal concentrations to assess the lipid peroxidation levels (LPX), catalase activity, hepatic glycogen content, and histological damage in the liver and gills of the fish Goodea atripinnis associated with chronic exposure (75 days). The LC(50) was 38.95 ± 0.33 mg/L. The results of the short-term exposure study indicate that Yerbimat can potentially induce oxidative stress in G. atripinnis, because LPX was increased in the gills and liver. Catalase activity was reduced in the gills but increased in the liver, whereas hepatic glycogen was depleted. Chronic exposure was associated with histopathological damage in the gills and liver, some of which was irreversible. Yerbimat represents a potential risk for aquatic biota; therefore, we recommend that its application be carefully considered. PMID:21305274

  20. Iron, copper, and manganese complexes with in vitro superoxide dismutase and/or catalase activities that keep Saccharomyces cerevisiae cells alive under severe oxidative stress.

    PubMed

    Ribeiro, Thales P; Fernandes, Christiane; Melo, Karen V; Ferreira, Sarah S; Lessa, Josane A; Franco, Roberto W A; Schenk, Gerhard; Pereira, Marcos D; Horn, Adolfo

    2015-03-01

    Due to their aerobic lifestyle, eukaryotic organisms have evolved different strategies to overcome oxidative stress. The recruitment of some specific metalloenzymes such as superoxide dismutases (SODs) and catalases (CATs) is of great importance for eliminating harmful reactive oxygen species (hydrogen peroxide and superoxide anion). Using the ligand HPClNOL {1-[bis(pyridin-2-ylmethyl)amino]-3-chloropropan-2-ol}, we have synthesized three coordination compounds containing iron(III), copper(II), and manganese(II) ions, which are also present in the active site of the above-noted metalloenzymes. These compounds were evaluated as SOD and CAT mimetics. The manganese and iron compounds showed both SOD and CAT activities, while copper showed only SOD activity. The copper and manganese in vitro SOD activities are very similar (IC50~0.4?mol dm(-3)) and about 70-fold higher than those of iron. The manganese compound showed CAT activity higher than that of the iron species. Analyzing their capacity to protect Saccharomyces cerevisiae cells against oxidative stress (H2O2 and the O2(•-) radical), we observed that all compounds act as antioxidants, increasing the resistance of yeast cells mainly due to a reduction of lipid oxidation. Especially for the iron compound, the data indicate complete protection when wild-type cells were exposed to H2O2 or O2(•-) species. Interestingly, these compounds also compensate for both superoxide dismutase and catalase deficiencies; their antioxidant activity is metal ion dependent, in the order iron(III)>copper(II)>manganese(II). The protection mechanism employed by the complexes proved to be independent of the activation of transcription factors (such as Yap1, Hsf1, Msn2/Msn4) and protein synthesis. There is no direct relation between the in vitro and the in vivo antioxidant activities. PMID:25511255

  1. Oxidation of nitric oxide by oxomanganese-salen complexes: a new mechanism for cellular protection by superoxide dismutase/catalase mimetics.

    PubMed Central

    Sharpe, Martyn A; Ollosson, Richard; Stewart, Victoria C; Clark, John B

    2002-01-01

    Manganese-salen complexes (Mn-Salen), including EUK-8 [manganese N,N'-bis(salicylidene)ethylenediamine chloride] and EUK-134 [manganese 3-methoxy N,N'-bis(salicylidene)ethylenediamine chloride], have been reported to possess combined superoxide dismutase (SOD) and catalase mimetic functions. Because of this SOD/catalase mimicry, EUK-8 and EUK-134 have been investigated as possible therapeutic agents in neurological disorders resulting from oxidative stress, including Alzheimer's disease, Parkinson's disease, stroke and multiple sclerosis. These actions have been explained by the ability of the Mn-Salen to remove deleterious superoxide (O(2)(-)) and H(2)O(2). However, in addition to oxidative stress, cells in models for neurodegenerative diseases may also be subjected to damage from reactive nitrogen oxides (nitrosative stress), resulting from elevated levels of NO and sister compounds, including peroxynitrite (ONOO(-)). We have been examining the interaction of EUK-8 and EUK-134 with NO and ONOO(-). We find that in the presence of a per-species (H(2)O(2), ONOO(-), peracetate and persulphate), the Mn-Salen complexes are oxidized to the corresponding oxo-species (oxoMn-Salen). OxoMn-Salens are potent oxidants, and we demonstrate that they can rapidly oxidize NO to NO(2) and also oxidize nitrite (NO(2)(-) to nitrate (NO(2)(-)). Thus these Mn-Salens have the potential to ameliorate cellular damage caused by both oxidative and nitrosative stresses, by the catalytic breakdown of O(2)(-), H(2)O(2), ONOO(-) and NO to benign species: O(2), H(2)O, NO(2)(-) and NO(3)(-). PMID:11994046

  2. Transcriptional upregulation of human tissue kallikrein 6 in ovarian cancer: clinical and mechanistic aspects.

    PubMed

    Shan, S J C; Scorilas, A; Katsaros, D; Diamandis, E P

    2007-01-29

    The human tissue kallikrein family (KLK for protein; KLK for gene) includes 15 members. Twelve kallikreins, including KLK6, are concurrently upregulated in ovarian cancer. However, the mechanism of this phenomenon remains unclear. In this study, we measured KLK6 expression in a large series of ovarian tissue cytosols and examined possible mechanisms of KLK6 up-regulation in ovarian cancer. Using a newly developed enzyme-linked immunosorbent assay (ELISA) with two monoclonal antibodies, we quantified KLK6 expression in ovarian tissue cytosols, and confirmed the upregulation of KLK6 in ovarian cancer and its unfavourable prognostic value. We then examined KLK6 mRNA expression using reverse transcription-polymerase chain reaction and established its good concordance with KLK6 protein expression. This finding suggested that the KLK6 gene is under transcriptional regulation. We then scrutinised a few mechanisms that could explain KLK6 upregulation. The relative abundance of two KLK6 mRNA transcripts was studied; we found the same differential expression pattern in all samples, regardless of KLK6 levels. Genomic mutation screening of all exons and the 5'-flanking region of the KLK6 gene identified two linked single-nucleotide polymorphisms in the 5'-untranslated region, but neither correlated with KLK6 expression. Ovarian cell lines were separately treated with five steroid hormones. None of the treatments produced significant effects on KLK6 expression. We conclude that KLK6 is transcriptionally upregulated in ovarian cancer, but probably not through alternative mRNA transcript expression, genomic mutation, or steroid hormone induction. PMID:17242704

  3. The homeobox gene HLXB9 is upregulated in a morphological subset of poorly differentiated hepatocellular carcinoma.

    PubMed

    Wilkens, Ludwig; Jaggi, Rolf; Hammer, Caroline; Inderbitzin, Daniel; Giger, Olivier; von Neuhoff, Nils

    2011-06-01

    The prognostic outcome for hepatocellular carcinoma (HCC) remains poor. Disease progression is accompanied by dedifferentiation of the carcinoma, a process that is not well understood. The aim of this study was to get more insight into the molecular characteristics of dedifferentiated carcinomas using high throughput techniques. Microarray-based global gene expression analysis was performed on five poorly differentiated HCC cell lines compared with non-neoplastic hepatic controls and a set of three cholangiolar carcinoma (CC) cell lines. The gene with the highest upregulation was HLXB9. HLXB9 is a gene of the homeobox genfamily important for the development of the pancreas. RT-PCR confirmed the upregulation of HLXB9 in surgical specimens of carcinoma tissue, suggesting its biological significance. Interestingly, HLXB9 upregulation was primary observed in poorly differentiated HCC with a pseudoglandular pattern compared with a solid pattern HCC or in moderate or well-differentiated HCC. Additional the expression of translated HLXB9, the protein HB9 (NCBI: NP_001158727), was analyzed by western blotting. Expression of HB9 was only detected in the cytoplasm but not in the nuclei of the HCC cells. For validation CC were also investigated. Again, we found an upregulation of HLXB9 in CC cells accompanied by an expression of HB9 in the cytoplasms of these tumor cells, respectively. In conclusion, homeobox HLXB9 is upregulated in poorly differentiated HCC with a pseudoglandular pattern. The translated HB9 protein is found in the cytoplasm of these HCC and CC. We therefore assume HLXB9 as a possible link in the understanding of the development of HCC and CC, respectively. PMID:21484430

  4. Hepatitis B virus X protein prevents apoptosis of hepatocellular carcinoma cells by upregulating SATB1 and HURP expression

    Microsoft Academic Search

    Tzu-Ching Kuo; Chuck C.-K. Chao

    2010-01-01

    Protein X from hepatitis B virus (HBV) appears to play a critical role in the development of hepatocellular carcinoma (HCC). The hepatoma upregulated protein (HURP) is also upregulated in a majority of HCC cases, therefore suggesting that HURP represents an oncogene. In this study, we describe a link between the viral protein HBx, HURP, and the establishment of cisplatin chemoresistance

  5. Rapid upregulation of heart antioxidant enzymes during arousal from estivation in the Giant African snail (Achatina fulica)

    E-print Network

    Tattersall, Glenn

    Rapid upregulation of heart antioxidant enzymes during arousal from estivation in the Giant African by upregulating intracellular antioxidant defenses in the heart, kidney, hepatopancreas and foot tissues increased in heart, hepatopancreas and foot. In heart, a rapid increase in MnSOD protein levels was observed

  6. Protective effects of lazaroid U74389F (16-desmethyl tirilazad) on endrin-induced lipid peroxidation and DNA damage in brain and liver and regional distribution of catalase activity in rat brain

    Microsoft Academic Search

    M. Bagchi; S. Ghosh; D. Bagchi; E. Hassoun; S. J. Stohs

    1995-01-01

    Endrin, a poly-halogenated cyclic hydrocarbon, induces hepatic lipid peroxidation, modulates calcium homeostasis, decreases membrane fluidity, and increases nuclear DNA damage. Little information is available on the neurotoxicity of endrin. The effects of endrin on lipid peroxidation, DNA damage, and regional distribution of catalase activity were assessed in rat brain and liver 24 h following an acute oral dose of 4.5

  7. Expression of superoxide dismutase, catalase and thermostable direct hemolysin by, and growth in the presence of various nitrogen and carbon sources of heat-shocked and ethanol-shocked Vibrio parahaemolyticus

    Microsoft Academic Search

    Ming-Lun Chiang; Cheng-Chun Chou

    2008-01-01

    Vibrio parahaemolyticus 690 was subjected either to heat shock at 42 °C or ethanol shock in the presence of 5% ethanol. The effects of those shocks on superoxide dismutase (SOD) and catalase (CAT) activities, and thermostable direct hemolysin (TDH) production were examined. In addition, the growth behaviors of the stressed and unstressed cells of V. parahaemolyticus in the presence of various

  8. Upregulation of early growth response factor-1 by bile acids requires mitogen-activated protein kinase signaling

    SciTech Connect

    Allen, Katryn [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Kim, Nam Deuk; Moon, Jeon-OK [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Department of Pharmacy, Pusan National University, Busan 609-735 (Korea, Republic of); Copple, Bryan L., E-mail: bcopple@kumc.ed [Department of Pharmacology, Toxicology, and Experimental Therapeutics, University of Kansas Medical Center, 4063 KLSIC, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States)

    2010-02-15

    Cholestasis results when excretion of bile acids from the liver is interrupted. Liver injury occurs during cholestasis, and recent studies showed that inflammation is required for injury. Our previous studies demonstrated that early growth response factor-1 (Egr-1) is required for development of inflammation in liver during cholestasis, and that bile acids upregulate Egr-1 in hepatocytes. What remains unclear is the mechanism by which bile acids upregulate Egr-1. Bile acids modulate gene expression in hepatocytes by activating the farnesoid X receptor (FXR) and through activation of mitogen-activated protein kinase (MAPK) signaling. Accordingly, the hypothesis was tested that bile acids upregulate Egr-1 in hepatocytes by FXR and/or MAPK-dependent mechanisms. Deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) stimulated upregulation of Egr-1 to the same extent in hepatocytes isolated from wild-type mice and FXR knockout mice. Similarly, upregulation of Egr-1 in the livers of bile duct-ligated (BDL) wild-type and FXR knockout mice was not different. Upregulation of Egr-1 in hepatocytes by DCA and CDCA was prevented by the MEK inhibitors U0126 and SL-327. Furthermore, pretreatment of mice with U0126 prevented upregulation of Egr-1 in the liver after BDL. Results from these studies demonstrate that activation of MAPK signaling is required for upregulation of Egr-1 by bile acids in hepatocytes and for upregulation of Egr-1 in the liver during cholestasis. These studies suggest that inhibition of MAPK signaling may be a novel therapy to prevent upregulation of Egr-1 in liver during cholestasis.

  9. Lipopolysaccharide induces up-regulation of CD14 molecule on monocytes in human whole blood.

    PubMed

    Marchant, A; Duchow, J; Delville, J P; Goldman, M

    1992-06-01

    We examined by flow cytometry the expression of lipopolysaccharide (LPS) receptor CD14 molecule on monocytes after addition of LPS to human whole blood. Within 30 min LPS induced an increase in monocyte CD14 expression, peaking between 1 and 3 h and followed by a slow decrease. Maximal increase in anti-CD14 monoclonal antibody binding sites was estimated as twofold the basal value. This effect, already observed with very low concentrations of LPS (10 pg/ml), was dose dependent. Protein synthesis was not involved in the CD14 hyperexpression since it was not influenced by co-incubation with cycloheximide. Finally, LPS-induced up-regulation of monocyte CD14 was associated with an increased binding of fluoresceinated LPS. We conclude that LPS in whole blood up-regulates the expression of its own CD14 receptor on monocytes, a phenomenon that could be relevant to the pathogenesis of gram-negative sepsis. PMID:1376269

  10. Upregulation of microRNA processing enzymes Drosha and Dicer in gestational diabetes mellitus.

    PubMed

    Rahimi, Giti; Jafari, Naser; Khodabakhsh, Mehnoush; Shirzad, Zohreh; Dogaheh, Hadi Peeri

    2015-02-01

    MicroRNAs (miRNAs) have been shown to play important roles in diverse cellular processes and linked to variety of disorders. Dicer and Drosha are two major enzymes in the miRNA biogenesis process. DGCR8 is the assistant of Drosha in the microprocessor complex. In this study, we evaluated the mRNA expression profiles of major miRNA processing machinery Drosha, Dicer, and DGCR8 in gestational diabetes mellitus (GDM), pregnant and healthy women. Our findings indicate that the expression levels of Drosha, Dicer and DGCR8 were upregulated in both pregnant and GDM patients compared to the control group. However, Drosha and Dicer were upregulated more than pregnant group. In conclusion, we detected dysregulation of Drosha, Dicer and DGCR8 expression in pregnant and GDM patients when compared to healthy control participants. Therefore, we favor the hypothesis that miRNAs are involved in the development of GDM. PMID:25295740

  11. FoxM1 Promotes Glioma Cells Progression by Up-Regulating Anxa1 Expression

    PubMed Central

    Cheng, Shi-Xiang; Tu, Yue; Zhang, Sai

    2013-01-01

    Forkhead box M1 (FoxM1) is a member of the forkhead transcription factor family and is overexpression in malignant gliomas. However, the molecular mechanisms by which FoxM1lead to glioma carcinogenesis and progression are still not well known. In the present study, we show that Anxa1 was overexpression in gliomas and predicted the poor outcome. Furthermore, Anxa1 closely related to the FoxM1 expression and was a direct transcriptional target of FoxM1. Overexpression of FoxM1 up-regulated Anxa1 expression, whereas suppression of FoxM1 expression down-regulated Anxa1 expression in glioma cells. Finally, FoxM1 enhanced the proliferation, migration, and angiogenesis in Anxa1-dependent manner both in vitro and in vivo. Our findings provide both clinical and mechanistic evidences that FoxM1 contributes to glioma development by directly up-regulating Anxa1 expression. PMID:23991102

  12. Up-regulation of cyclooxygenase-2 by product-prostaglandin E2

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Hughes-Fulford, M.

    1997-01-01

    The development of prostate cancer has been linked to high level of dietary fat intake. Our laboratory investigates the connection between cancer cell growth and fatty acid products. Studying human prostatic carcinoma PC-3 cells, we found that prostaglandin E2 (PGE2) increased cell growth and up-regulated the gene expression of its own synthesizing enzyme, cyclooxygenase-2 (COX-2). PGE2 increased COX-2 mRNA expression dose-dependently with the highest levels of stimulation seen at the 3-hour period following PGE2 addition. The NSAID flurbiprofen (5 microM), in the presence of exogenous PGE2, inhibited the up-regulation of COX-2 mRNA and cell growth. These data suggest that the levels of local intracellular PGE2 play a major role in the growth of prostate cancer cells through an activation of COX-2 gene expression.

  13. Upregulation of soluble epoxide hydrolase in proximal tubular cells mediated proteinuria-induced renal damage

    E-print Network

    Hammock, Bruce D.

    -induced renal damage Qian Wang,1,3 * Wei Pang,2 * Zhuan Cui,1 Junbao Shi,1 Yan Liu,2 Bo Liu,2 Yunfeng Zhou,2 Youfei Guan,2 Bruce D. Hammock,4 Yue Wang,1 * and Yi Zhu2 * 1 Department of Nephrology, Peking University, Shi J, Liu Y, Liu B, Zhou Y, Guan Y, Hammock BD, Wang Y, Zhu Y. Upregulation of soluble epoxide hydro

  14. Cyclin-dependent kinase-5 prevents neuronal apoptosis through ERK-mediated upregulation of Bcl2

    Microsoft Academic Search

    C X Wang; J H Song; D K Song; V W Yong; A Shuaib; C Hao

    2006-01-01

    Cyclin-dependent kinase-5 (Cdk5) is required for neuronal survival, but its targets in the apoptotic pathways remain unknown. Here, we show that Cdk5 kinase activity prevents neuronal apoptosis through the upregulation of Bcl-2. Treatment of SH-SY5Y cells with retinoid acid (RA) and brain-derived neurotrophic factor (BDNF) generates differentiated neuron-like cells. DNA damage triggers apoptosis in the undifferentiated cells through mitochondrial pathway;

  15. Chronic Administration of Nifedipine Induces Up-regulation of Functional Calcium Channels in Rat Myocardium

    Microsoft Academic Search

    Patricio E. Morgan; Ernesto A. Aiello; Gladys E. Chiappe de Cingolani; Alicia R. Mattiazzi; Horacio E. Cingolani

    1999-01-01

    Previous studies from our laboratory demonstrated the up-regulation of cardiac dihydropyridine (DHP) receptors in rabbits chronically treated with nifedipine (NIFE). The goal of the present study was to further examine the functionality of this increased number of receptors by analysing different steps of excitation contraction coupling mechanism in adult rats chronically treated with NIFE (a single 10-mg oral dose\\/kg\\/day for

  16. Rapid systemic up-regulation of genes after heat-wounding and electrical stimulation

    NASA Technical Reports Server (NTRS)

    Davies, E.; Vian, A.; Vian, C.; Stankovic, B.

    1997-01-01

    When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.

  17. p53 is upregulated in Alzheimer's disease and induces tau phosphorylation in HEK293a cells

    Microsoft Academic Search

    Claudie Hooper; Eirini Meimaridou; Mahvash Tavassoli; Gerry Melino; Simon Lovestone; Richard Killick

    2007-01-01

    p53 and tau are both associated with neurodegenerative disorders. Here, we show by Western blotting that p53 is upregulated approximately 2-fold in the superior temporal gyrus of Alzheimer's patients compared to healthy elderly control subjects. Moreover, p53 was found to induce phosphorylation of human 2N4R tau at the tau-1\\/AT8 epitope in HEK293a cells. Confocal microscopy revealed that tau and p53

  18. Up-regulation of Duffy antigen receptor expression in children with renal disease

    Microsoft Academic Search

    Xue-Hui Liu; Terence J. Hadley; Lian Xu; Stephen C. Peiper; Patricio E. Ray

    1999-01-01

    Up-regulation of Duffy antigen receptor expression in children with renal disease.BackgroundThe Duffy antigen chemokine receptor (DARC) is a promiscuous chemokine receptor that binds chemokines from the C-X-C and C-C families. DARC was initially described on red blood cells, but subsequent studies have demonstrated DARC protein expression on renal endothelial and epithelial cells, even in Duffy-negative individuals whose red cells lack

  19. Eurycomanone induce apoptosis in HepG2 cells via up-regulation of p53

    PubMed Central

    Zakaria, Yusmazura; Rahmat, Asmah; Pihie, Azimahtol Hawariah Lope; Abdullah, Noor Rain; Houghton, Peter J

    2009-01-01

    Background Eurycomanone is a cytotoxic compound found in Eurycoma longifolia Jack. Previous studies had noted the cytotoxic effect against various cancer cell lines. The aim of this study is to investigate the cytotoxicity against human hepato carcinoma cell in vitro and the mode of action. The cytotoxicity of eurycomanone was evaluated using MTT assay and the mode of cell death was detected by Hoechst 33258 nuclear staining and flow cytometry with Annexin-V/propidium iodide double staining. The protein expression Bax, Bcl-2, p53 and cytochrome C were studied by flow cytometry using a spesific antibody conjugated fluorescent dye to confirm the up-regulation of p53 and Bax in cancer cells. Results The findings suggested that eurycomanone was cytotoxic on cancerous liver cell, HepG2 and less toxic on normal cells Chang's liver and WLR-68. Furthermore, various methods proved that apoptosis was the mode of death in eurycomanone-treated HepG2 cells. The characteristics of apoptosis including chromatin condensation, DNA fragmentation and apoptotic bodies were found following eurycomanone treatment. This study also found that apoptotic process triggered by eurycomanone involved the up-regulation of p53 tumor suppressor protein. The up-regulation of p53 was followed by the increasing of pro-apoptotic Bax and decreasing of anti-apoptotic Bcl-2. The increased of cytochrome C levels in cytosol also results in induction of apoptosis. Conclusion The data suggest that eurycomanone was cytotoxic on HepG2 cells by inducing apoptosis through the up-regulation of p53 and Bax, and down-regulation of Bcl-2. PMID:19508737

  20. Airway epithelial platelet-activating factor receptor expression is markedly upregulated in chronic obstructive pulmonary disease

    PubMed Central

    Shukla, Shakti Dhar; Sohal, Sukhwinder Singh; Mahmood, Malik Quasir; Reid, David; Muller, Hans Konrad; Walters, Eugene Haydn

    2014-01-01

    Background We recently published that platelet-activating factor receptor (PAFr) is upregulated on the epithelium of the proximal airways of current smokers and also in bronchial epithelial cells exposed to cigarette smoke extract. These treated cells also showed upregulation of Streptococcus pneumoniae adhesion. Bacterial wall phosphorylcholine specifically binds to PAFr expressed on airway epithelium, thus facilitating adherence and tissue invasion, which may be relevant to chronic obstructive pulmonary disease (COPD). Moreover, the use of inhaled corticosteroids (ICS) in COPD patients is associated with an increased risk of invasive respiratory pneumococcal infections. Objective In this study, we have investigated whether PAFr expression is especially upregulated in airway epithelium in COPD patients and whether this expression may be modulated by ICS therapy. Methods We cross-sectionally evaluated PAFr expression in bronchial biopsies from 15 COPD patients who were current smokers (COPD-smokers) and 12 COPD-ex-smokers, and we compared these to biopsies from 16 smokers with normal lung function. We assessed immunostaining with anti-PAFr monoclonal antibody. We also used material from a previous double-blinded randomized placebo-controlled 6-month ICS intervention study in COPD patients to explore the effect of ICS on PAFr expression. We employed computer-aided image analysis to quantify the percentage of epithelium stained for PAFr. Results Markedly enhanced expression of PAFr was found in both COPD-smokers (P<0.005) and COPD-ex-smokers (P<0.002) compared to smokers with normal lung function. There was little evidence that PAFr expression was affected by ICS therapy over 6 months. Conclusion Epithelial PAFr expression is upregulated in smokers, especially in those with COPD, and is not obviously affected by ICS therapy. PMID:25143722

  1. The glutathione peroxidase homologous gene from Chlamydomonas reinhardtii is transcriptionally up-regulated by singlet oxygen

    Microsoft Academic Search

    Urs Leisinger; Karin Rüfenacht; Beat Fischer; Manuel Pesaro; Arik Spengler; Alexander J. B. Zehnder; Rik I. L. Eggen

    2001-01-01

    The glutathione peroxidase homologous gene (Gpxh gene) in Chlamydomonas reinhardtii is up-regulated under oxidative stress conditions. The Gpxh gene showed a remarkably strong and fast induction by the singlet oxygen-generating photosensitizers neutral red, methylene blue and rose Bengal. The Gpxh mRNA levels strongly increased, albeit much more slowly, upon exposure to the organic hydroperoxides tert-butyl hydroperoxide (t-BOOH) and cumene hydroperoxide.

  2. Upregulation of articular synovial membrane ?-opioid-like receptors in an acute equine synovitis model.

    PubMed

    van Loon, J P A M; de Grauw, J C; Brunott, A; Weerts, E A W S; van Weeren, P R

    2013-04-01

    Intra-articular injection of opioids provides analgesia in painful equine joints and ?-opioid receptors (MORs) have been demonstrated in equine synovial membranes. The aim of this study was to determine whether acute inflammatory conditions will lead to up-regulation of MOR in equine synovial membranes and whether anti-inflammatory treatment can prevent any such upregulation. In a two-period, blinded, placebo-controlled randomised cross-over design, lipopolysaccharide (LPS, 1.0 ng) was injected into the left or right middle carpal joint of seven healthy ponies. Arthroscopy and synovial membrane biopsy was performed under general anaesthesia at baseline, 48 h (T48) and 672 h (T672) after LPS injection, with ponies assigned to receive either phenylbutazone (PBZ 2.2mg/kg PO BID) or placebo from 2h post-LPS. Ponies were scored for pain and lameness. Repeated synovial fluid samples were obtained and the degree of synovitis scored both macroscopically and microscopically. The density and staining pattern of MOR-like protein in synovial membrane biopsies over the course of the synovitis with or without PBZ treatment was evaluated using immunohistochemical techniques. LPS injection consistently induced a severe transient synovitis. Pain and lameness were significantly attenuated by treatment with PBZ. Up-regulation of MOR-like protein in the inflamed equine synovial membrane could be demonstrated in the placebo treated animals, but not in the PBZ-treated animals overall, although there were no significant differences at any individual time-point between the two groups. It was concluded that acute inflammation will up-regulate MOR, while anti-inflammatory treatment will attenuate this response. PMID:22939088

  3. Sulf-2, a Proangiogenic Heparan Sulfate Endosulfatase, Is Upregulated in Breast Cancer1

    Microsoft Academic Search

    Megumi Morimoto-Tomita; Kenji Uchimura; Annette Bistrup; David H. Lum; Mikala Egeblad; Nancy Boudreau; Zena Werb; Steven D. Rosen

    Sulf-2 is an endosulfatase with activity against glucosamine-6-sulfate modifications within subregions of intact heparin. The enzyme has the potential to mod- ify the sulfation status of extracellular heparan sulfate proteoglycan (HSPG) glycosaminoglycan chains and thereby to regulate interactions with HSPG-binding pro- teins. In the present investigation, data mining from pub- lished studies was employed to establish Sulf-2 mRNA upregulation in

  4. Ascorbic acid upregulates myelin gene expression in C6 glioma cells

    Microsoft Academic Search

    I. Laszkiewicz; R. C. Wiggins; G. Konat

    1992-01-01

    The effect of ascorbic acid (AA) on rat glioma C6 cells was studied. At physiological AA concentrations of 0.1 and 1 mM, no morphological and no proliferative alterations in the C6 cultures were detectable. Although the total RNA content per cell was not affected by the AA-treatment, AA upregulated the expression of myelin-specific genes, i.e. proteolipid protein (PLP) and myelin-associated

  5. Pharmacological Induction of Ischemic Tolerance by Glutamate Transporter1 (EAAT2) Upregulation

    Microsoft Academic Search

    Kon Chu; Soon-Tae Lee; Dong-In Sinn; Song-Yi Ko; Eun-Hee Kim; Jeong-Min Kim; Se-Jeong Kim; Keun-Hwa Jung; Eun-Cheol Song; Sang Kun Lee; Manho Kim; Jae-Kyu Roh

    2010-01-01

    Background and Purpose—Astrocytic glutamate transporter protein, GLT-1 (EAAT2), recovers extracellular glutamate and ensures that neurons are protected from excess stimulation. Recently, -lactam antibiotics, like ceftriaxone (CTX), were reported to induce the upregulation of GLT-1. Here, we investigated ischemic tolerance induction by CTX in an experimental model of focal cerebral ischemia. Methods—CTX (200 mg\\/kg per day, IP) was administered for 5

  6. Up-Regulated Cten by FGF2 Contributes to FGF2-Mediated Cell Migration

    PubMed Central

    Hung, Shih-Ya; Shih, Yi-Ping; Chen, Michelle; Lo, Su Hao

    2015-01-01

    Cten is a focal adhesion molecule that is expressed at very low levels in most normal tissues. Nonetheless, its expression has been found to increase dramatically in many types of cancer including colorectal, breast, gastric, and pancreatic cancer, suggesting that cten may play a critical role during tumorigenesis. To study the mechanisms that induce cten expression and the function of up-regulated cten, we examined the effects of several cancer-associated growth factors and cytokines on cten expression. We found that EGF, FGF2, NGF, PDGF, TGF-?, IGF-1, IL-6, and IL-13 were able to induce cten expression in a dose- and time-dependent manner. The Mek-Erk and PI3K-Akt pathways were two main signaling cascades responsible for cten up-regulation, whereas the Jak-Stat pathway could contribute to the increase in some conditions. Since many of these factors are known to promote cell migration, we hypothesized that up-regulated cten might contribute to this process. This hypothesis was investigated in FGF2-mediated cell migration. Silencing of cten not only reduced regular cell motility but also FGF2-mediated cell migration. Overexpression of cten promoted cell migration and FGF2 treatment failed to further enhance cell migration. Our findings that (1) cten is a common downstream molecule of these cancer-associated growth factors and cytokines; and that (2) up-regulated cten modulates cell migration induced by FGF2 and likely other growth factors as well, strongly suggest that cten could be a potential downstream therapeutic target for treating cancers associated with aberrant signaling of these growth factors and cytokines. PMID:23625726

  7. Interferon ?-Inducible Protein 27 (IFI27) is Upregulated in Psoriatic Skin and Certain Epithelial Cancers

    Microsoft Academic Search

    Sari Suomela; Li Cao; Anne Bowcock; Ulpu Saarialho-Kere

    2004-01-01

    IFI27 is an interferon ?-inducible protein found to be upregulated in lesional and non-lesional psoriatic skin in a gene array study. To further characterize its function, we studied by in situ hybridization whether IFI27 is expressed in psoriasis, other inflammatory skin diseases, and wound repair in vivo. We also examined its regulation by different growth factors and anti-psoriatic agents using

  8. MDA5 is SUMOylated by PIAS2? in the upregulation of Type I interferon signaling

    Microsoft Academic Search

    Jihuan Fu; Yanbao Xiong; Youli Xu; Genhong Cheng; Hong Tang

    2011-01-01

    Retinoic acid-inducible protein I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are cytosolic viral RNA sensors that induce type I interferon production (IFN). In this study, we found that MDA5 undergoes inducible SUMOylation by small ubiquitin-like modifier-1 (SUMO-1) in response to polyI:C stimulation. Enhanced SUMOylation of MDA5 by exogenously expressed SUMO-conjugating enzyme Ubc9 correlated with upregulation of IFN expression and

  9. Sulpiride, but not haloperidol, up-regulates ?-hydroxybutyrate receptors in vivo and in cultured cells

    Microsoft Academic Search

    Charline Ratomponirina; Serge Gobaille; Yann Hodé; Véronique Kemmel; Michel Maitre

    1998-01-01

    Five days of ?-hydroxybutyrate (GHB) administration (3×500 mg kg?1 day?1 i.p.) to rats resulted in a significant decrease in the density of GHB receptors measured in the whole rat brain without modification of their corresponding affinity. Similar administration of (?)-sulpiride (2×100 mg kg?1 day?1 i.p. for 5 days) induces an up-regulation of GHB receptors without change in their dissociation constants

  10. Up-Regulation of c-Fos Associated with Neuronal Apoptosis Following Intracerebral Hemorrhage.

    PubMed

    Chen, Xiaomei; Shen, Jiabing; Wang, Yang; Chen, Xiaojing; Yu, Shi; Shi, Huili; Huo, Keke

    2015-04-01

    The proto-oncogene c-Fos is an important member of the activating protein 1 (AP-1) transcription complex involved in major cellular functions such as transformation, proliferation, differentiation, and apoptosis. The expression of c-Fos is very tightly regulated and responses rapidly and transiently to a plethora of apoptotic stimuli. However, it is still unclear how c-Fos functions on neuronal activities following intracerebral hemorrhage (ICH). In the present studies, we uncovered that the up-regulation of c-Fos is related to neuronal apoptosis following ICH probably via FasL/Fas apoptotic pathway. From the results of Western blot and immunohistochemistry, we obtained that c-Fos is significantly up-regulated surrounding the hematoma following ICH and co-locates with active caspase-3 in the neurons. Besides, electrophoretic mobility shift assay exhibits high AP-1 DNA-binding activities in ICH groups due to the increase of c-Fos expression. In addition, there are concomitant up-regulation of Fas ligand (FasL), which is the target protein of AP-1, Fas, active caspase-8, and active caspase-3 in vivo and in vitro studies. What is more, our in vitro study showed that using c-Fos-specific RNA interference in primary cortical neurons, the expression of FasL and active caspase-3 are suppressed. Thus, our results indicated that c-Fos might exert its pro-apoptotic function on neuronal apoptosis following ICH. PMID:25354492

  11. Acid Ceramidase Upregulation in Prostate Cancer Cells Confers Resistance to Radiation: AC Inhibition, a Potential Radiosensitizer

    PubMed Central

    Mahdy, Ayman EM; Cheng, Joseph C; Li, Jun; Elojeimy, Saeed; Meacham, William D; Turner, Lorianne S; Bai, Aiping; Gault, Christopher R; McPherson, Alex S; Garcia, Nicole; Beckham, Thomas H; Saad, Antonio; Bielawska, Alicja; Bielawski, Jacek; Hannun, Yusuf A; Keane, Thomas E; Taha, Mohhammed I; Hammouda, Hisham M; Norris, James S; Liu, Xiang

    2008-01-01

    Radiation resistance in a subset of prostate tumors remains a challenge to prostate cancer radiotherapy. The current study on the effects of radiation on prostate cancer cells reveals that radiation programs an unpredicted resistance mechanism by upregulating acid ceramidase (AC). Irradiated cells demonstrated limited changes of ceramide levels while elevating levels of sphingosine and sphingosine-1-phosphate. By genetically downregulating AC with small interfering RNA (siRNA), we observed radiosensitization of cells using clonogenic and cytotoxicity assays. Conversely, AC overexpression further decreased sensitivity to radiation. We also observed that radiation-induced AC upregulation was sufficient to create cross-resistance to chemotherapy as demonstrated by decreased sensitivity to Taxol and C6 ceramide compared to controls. Lower levels of caspase 3/7 activity were detected in cells pretreated with radiation, also indicating increased resistance. Finally, utilization of the small molecule AC inhibitor, LCL385, sensitized PPC-1 cells to radiation and significantly decreased tumor xenograft growth. These data suggest a new mechanism of cancer cell resistance to radiation, through upregulation of AC that is, in part, mediated by application of the therapy itself. An improved understanding of radiotherapy and the application of combination therapy achieved in this study offer new opportunities for the modulation of radiation effects in the treatment of cancer. PMID:19107118

  12. Six1 Promotes Proliferation of Pancreatic Cancer Cells via Upregulation of Cyclin D1 Expression

    PubMed Central

    Li, Zhaoming; Tian, Tian; Lv, Feng; Chang, Yu; Wang, Xinhua; Zhang, Lei; Li, Xin; Li, Ling; Ma, Wang; Wu, Jingjing; Zhang, Mingzhi

    2013-01-01

    Six1 is one of the transcription factors that act as master regulators of development and are frequently dysregulated in cancers. However, the role of Six1 in pancreatic cancer is not clear. Here we show that the relative expression of Six1 mRNA is increased in pancreatic cancer and correlated with advanced tumor stage. In vitro functional assays demonstrate that forced overexpression of Six1 significantly enhances the growth rate and proliferation ability of pancreatic cancer cells. Knockdown of endogenous Six1 decreases the proliferation of these cells dramatically. Furthermore, Six1 promotes the growth of pancreatic cancer cells in a xenograft assay. We also show that the gene encoding cyclin D1 is a direct transcriptional target of Six1 in pancreatic cancer cells. Overexpression of Six1 upregulates cyclin D1 mRNA and protein, and significantly enhances the activity of the cyclin D1 promoter in PANC-1 cells. We demonstrate that Six1 promotes cell cycle progression and proliferation by upregulation of cyclin D1. These data suggest that Six1 is overexpressed in pancreatic cancer and may contribute to the increased cell proliferation through upregulation of cyclin D1. PMID:23527134

  13. 20-Hydroxyecdysone upregulates Atg genes to induce autophagy in the Bombyx fat body.

    PubMed

    Tian, Ling; Ma, Li; Guo, Enen; Deng, Xiaojuan; Ma, Sanyuan; Xia, Qingyou; Cao, Yang; Li, Sheng

    2013-08-01

    Autophagy is finely regulated at multiple levels and plays crucial roles in development and disease. In the fat body of the silkworm, Bombyx mori, autophagy occurs and Atg gene expression peaks during the nonfeeding molting and pupation stages when the steroid hormone (20-hydroxyecdysone; 20E) is high. Injection of 20E into the feeding larvae upregulated Atg genes and reduced TORC1 activity resulting in autophagy induction in the fat body. Conversely, RNAi knockdown of the 20E receptor partner (USP) or targeted overexpression of a dominant negative mutant of the 20E receptor (EcR (DN) ) in the larval fat body reduced autophagy and downregulated the Atg genes, confirming the importance of 20E-induction of Atg gene expression during pupation. Moreover, in vitro treatments of the larval fat body with 20E upregulated the Atg genes. Five Atg genes were potentially 20E primary-responsive, and a 20E response element was identified in the Atg1 (ortholog of human ULK1) promoter region. Furthermore, RNAi knockdown of 4 key genes (namely Br-C, E74, HR3 and ?ftz-F1) in the 20E-triggered transcriptional cascade reduced autophagy and downregulated Atg genes to different levels. Taken together, we conclude that in addition to blocking TORC1 activity for autophagosome initiation, 20E upregulates Atg genes to induce autophagy in the Bombyx fat body. PMID:23674061

  14. 20-hydroxyecdysone upregulates Atg genes to induce autophagy in the Bombyx fat body

    PubMed Central

    Tian, Ling; Ma, Li; Guo, Enen; Deng, Xiaojuan; Ma, Sanyuan; Xia, Qingyou; Cao, Yang; Li, Sheng

    2013-01-01

    Autophagy is finely regulated at multiple levels and plays crucial roles in development and disease. In the fat body of the silkworm, Bombyx mori, autophagy occurs and Atg gene expression peaks during the nonfeeding molting and pupation stages when the steroid hormone (20-hydroxyecdysone; 20E) is high. Injection of 20E into the feeding larvae upregulated Atg genes and reduced TORC1 activity resulting in autophagy induction in the fat body. Conversely, RNAi knockdown of the 20E receptor partner (USP) or targeted overexpression of a dominant negative mutant of the 20E receptor (EcRDN) in the larval fat body reduced autophagy and downregulated the Atg genes, confirming the importance of 20E-induction of Atg gene expression during pupation. Moreover, in vitro treatments of the larval fat body with 20E upregulated the Atg genes. Five Atg genes were potentially 20E primary-responsive, and a 20E response element was identified in the Atg1 (ortholog of human ULK1) promoter region. Furthermore, RNAi knockdown of 4 key genes (namely Br-C, E74, HR3 and ?ftz-F1) in the 20E-triggered transcriptional cascade reduced autophagy and downregulated Atg genes to different levels. Taken together, we conclude that in addition to blocking TORC1 activity for autophagosome initiation, 20E upregulates Atg genes to induce autophagy in the Bombyx fat body. PMID:23674061

  15. Up-regulation of Bcl-2 by redox signals in glomerular mesangial cells.

    PubMed

    Sandau, K B; Brüne, B

    2000-01-01

    The mediators nitric oxide (NO) and superoxide (O2-) are known to regulate cell death and survival. In mesangial cells (MC), NO induced apoptosis and in higher concentrations necrosis. Intriguingly, cogeneration of NO and O2- in a balanced ratio promoted cell protection. Under these conditions, we noticed the accumulation of the anti-apoptotic protein Bcl-2. Its up-regulation is based on an increase in mRNA and protein level. To investigate whether oxidative stress elicits Bcl-2 expression in general, we further used the chemically unrelated oxidative agents diamide and butyl hydroperoxide. Both stimulated mRNA and protein up-regulation of Bcl-2. But in contrast to diamide, butyl hydroperoxide evoked apoptosis and necrosis despite Bcl-2 accumulation. As diamide was non-toxic, we used diamide as a Bcl-2 activator to protect MC against a subsequent toxic dose of NO. We conclude that redox changes promote Bcl-2 up-regulation that may confer cellular protection towards apoptosis. PMID:10713727

  16. Up-regulation of miR-21 by HER2/neu Signaling Promotes Cell Invasion*

    PubMed Central

    Huang, Tzu-Hsuan; Wu, Fangting; Loeb, Gabriel B.; Hsu, Ruby; Heidersbach, Amy; Brincat, Allison; Horiuchi, Dai; Lebbink, Robert J.; Mo, Yin-Yuan; Goga, Andrei; McManus, Michael T.

    2009-01-01

    The cell surface receptor tyrosine kinase HER2/neu enhances tumor metastasis. Recent studies suggest that deregulated microRNA (miRNA) expression promotes invasion and metastasis of cancer cells; we therefore explored the possibility that HER2/neu signaling induces the expression of specific miRNAs involved in this process. We identified a putative oncogenic miRNA, miR-21, whose expression is correlated with HER2/neu up-regulation and is functionally involved in HER2/neu-induced cell invasion. We show that miR-21 is up-regulated via the MAPK (ERK1/2) pathway upon stimulation of HER2/neu signaling in breast cancer cells, and overexpression of other ERK1/2 activators such as RASV12 or ID-1 is sufficient to induce miR-21 up-regulation in HER2/neu-negative breast cancer cells. Furthermore, the metastasis suppressor protein PDCD4 (programmed cell death 4) is down-regulated by miR-21 in breast cancer cells expressing HER2/neu. Our data reveal a mechanism for HER2/neu-induced cancer cell invasion via miRNA deregulation. In addition, our results identify miR-21 as a potential therapeutic target for the prevention of breast cancer invasion and metastasis. PMID:19419954

  17. Growth hormone upregulates intestinal trefoil factor expression in the ileum of rats after ?-radiation.

    PubMed

    Posadas, Sinforiano J; Largo, Carlota; Merino, Jose J; Elvira, Marcos; Gonzalez, Gonzalo; Caz, Victor; Caballero, Isabel; De Miguel, Enrique

    2011-02-01

    Growth hormone (GH) and intestinal trefoil factor (ITF) have been involved in intestinal protection and repair. This study investigates the effects of GH administration on ITF expression and histological changes associated with tissue injury in an intestinal rat model of radiation. Adult male rats were divided into four groups: control, GH, radiation and radiation + GH (GHyRAD). Ileum samples were obtained at 2 or 72 h after radiation and processed to determine ITF levels (mRNA and protein) by quantitative polymerase chain reaction, Western blot and immunohistochemistry. In addition, goblet ITF-positive cells were identified by immunohistochemistry at 72 h. Our results showed an upregulation of mRNA and protein production of ITF in ileum samples after GH and radiation + GH compared with control and irradiated samples. Irradiation alone affected ITF protein expression. However, irradiation after GH pretreatment produced the highest ITF mRNA and protein levels at both the tested time points. ITF-producing goblet cells were identified in intestinal villi (apical location). GH treatment increased the number of ITF-producing goblet cells, and radiation after GH treatment displayed further increase in the number of ITF-positive goblet cells. GH upregulates ITF in normal intestinal tissue. This upregulation is higher when radiation is given after GH treatment. Nevertheless, the mechanism by which GH regulates ITF expression remains unclear and is still under investigation. These results could open up new avenues in the therapeutic reparative and protective effects of GH during radiotherapy and chemotherapy. PMID:21321317

  18. Perlecan Up-Regulation of FRNK Suppresses Smooth Muscle Cell Proliferation via Inhibition of FAK Signaling

    PubMed Central

    Walker, Heather A.; Whitelock, John M.; Garl, Pamela J.; Nemenoff, Raphael A.; Stenmark, Kurt R.; Weiser-Evans, Mary C.M.

    2003-01-01

    We previously reported that fully assembled basement membranes are nonpermissive to smooth muscle cell (SMC) replication and that perlecan (PN), a basement membrane heparan sulfate proteoglycan, is a dominant effector of this response. We report here that SMC adhesion to basement membranes, and perlecan in particular, up-regulate the expression of focal adhesion kinase-related nonkinase (FRNK), a SMC-specific endogenous inhibitor of FAK, which subsequently suppresses FAK-mediated, ERK1/2-dependent growth signals. Up-regulation of FRNK by perlecan is actively and continuously regulated. Relative to the matrix proteins studied, the effects are unique to perlecan, because plating of SMCs on several other basement membrane proteins is associated with low levels of FRNK and corresponding high levels of FAK and ERK1/2 phosphorylation and SMC growth. Perlecan supports SMC adhesion, although there is reduced cell spreading compared with fibronectin (FN), laminin (LN), or collagen type IV (IV). Despite the reduction in cell spreading, we report that perlecan-induced up-regulation of FRNK is independent of cell shape changes. Growth inhibition by perlecan was rescued by overexpressing a constitutively active FAK construct, but overexpressing kinase-inactivated mutant FAK or FRNK attenuated fibronectin-stimulated growth. These data indicate that perlecan functions as an endogenously produced inhibitor of SMC growth at least in part through the active regulation of FRNK expression. FRNK, in turn, may control SMC growth by downregulating FAK-dependent signaling events. PMID:12802066

  19. Upregulation of galectin-3 in immortalized Schwann cells IFRS1 under diabetic conditions.

    PubMed

    Tsukamoto, Masami; Sango, Kazunori; Niimi, Naoko; Yanagisawa, Hiroko; Watabe, Kazuhiko; Utsunomiya, Kazunori

    2015-03-01

    A spontaneously immortalized adult Fischer rat Schwann cell line IFRS1 retains the characteristic features of normal Schwann cells, and can be a useful tool for the study of diabetic neuropathy. In the present study, we examined the effects of high glucose and 3-deoxyglucosone (3-DG) on the viability and the protein expression of advanced glycation endproducts (AGE)-binding proteins, such as galectin-3 (GAL-3) and receptor for AGE (RAGE) in IFRS1 cells. Exposure to 30mM of glucose or 0.2mM of 3-DG for 7 days failed to impair the IFRS1 cell viability, but significantly upregulated the expression of GAL-3. The same exposure tended to increase the expression of RAGE, but the changes were not significant. The high glucose-induced upregulation of GAL-3 was attenuated by cotreatment with 0.2mM of an anti-glycated agent aminoguanidine or 20nM of an anti-oxidant trans-resveratrol. In addition, treatment of IFRS1 cells with 1?g/ml of recombinant GAL-3 for 48h resulted in the upregulation of B-cell lymphoma 2 (Bcl-2) and the downregulation of 4-hydroxynonenal (4HNE). These findings suggest the involvement of GAL-3 in the glycation and oxidative stress under diabetic conditions and its cytoprotective role in Schwann cells. PMID:25481849

  20. Low-level laser therapy promotes dendrite growth via upregulating brain-derived neurotrophic factor expression

    NASA Astrophysics Data System (ADS)

    Meng, Chengbo; He, Zhiyong; Xing, Da

    2014-09-01

    Downregulation of brain-derived neurotrophic factor (BDNF) in the hippocampus occurs early in the progression of Alzheimer's disease (AD). Since BDNF plays a critical role in neuronal survival and dendrite growth, BDNF upregulation may contribute to rescue dendrite atrophy and cell loss in AD. Low-level laser therapy (LLLT) has been demonstrated to regulate neuronal function both in vitro and in vivo. In the present study, we found that LLLT rescued neurons loss and dendritic atrophy via the increase of both BDNF mRNA and protein expression. In addition, dendrite growth was improved after LLLT, characterized by upregulation of PSD95 expression, and the increase in length, branching, and spine density of dendrites in hippocampal neurons. Together, these studies suggest that upregulation of BDNF with LLLT can ameliorate A?-induced neurons loss and dendritic atrophy, thus identifying a novel pathway by which LLLT protects against A?-induced neurotoxicity. Our research may provide a feasible therapeutic approach to control the progression of Alzheimer's disease.

  1. Regional upregulation of hippocampal melatonin MT2 receptors by valproic acid: therapeutic implications for Alzheimer's disease.

    PubMed

    Bahna, Sarra G; Sathiyapalan, Arani; Foster, Jane A; Niles, Lennard P

    2014-07-25

    We have reported that clinically relevant concentrations of valproic acid (VPA) upregulate the G protein-coupled melatonin MT1 receptor in rat C6 glioma cells, and both MT1 and MT2 receptors in the rat hippocampus. The melatonin MT2 receptor is relatively enriched in the hippocampus, where it is thought to be involved in modulating synaptic plasticity and cognitive function. Importantly, a significant decrease in MT2 expression has been observed in the hippocampus of Alzheimer's patients. Therefore, we examined whether the global upregulation of this receptor (and also the MT1) by VPA, observed in earlier RT-PCR and real time PCR studies, could be localized to more discrete hippocampal regions, which are involved in cognitive function. In situ hybridization of rat brain slices, following chronic VPA treatment (3mg/mL or 4mg/mL in drinking water), revealed a significant upregulation of the MT2 receptor mRNA in the CA1, CA2, CA3 and dentate gyrus (DG) regions of the rat hippocampus. In contrast, the MT1 receptor was not detected in the hippocampus by in situ hybridization. The significant induction of melatonin MT2 receptor expression by VPA in hippocampal regions involved in learning, memory and/or neural stem cell proliferation, suggests that a combinatorial therapeutic strategy involving VPA together with melatonin or other MT2 agonists, would be beneficial in neurodegenerative disorders such as Alzheimer's disease. PMID:24909617

  2. Upregulation of survivin by leptin/STAT3 signaling in MCF-7 cells

    SciTech Connect

    Jiang Haiping [Department of Radiation Oncology, Shandong Tumor Hospital and Institute, Jinan, Shandong province (China); Tianjin Medical University Cancer Hospital, Tianjin (China); Yu Jinming [Department of Radiation Oncology, Shandong Tumor Hospital and Institute, Jinan, Shandong province (China)], E-mail: sthisci@yahoo.com; Guo Hongbo; Song Hao; Chen Shaoqing [Department of Radiation Oncology, Shandong Tumor Hospital and Institute, Jinan, Shandong province (China)

    2008-03-28

    Leptin and its receptors are overexpressed in breast cancer tissues and correlate with poor prognosis. Survivin, a member of the inhibitor of apoptosis protein (IAP) gene family, is generally upregulated in tumor tissues and prevents tumor cells from apoptosis. Here we showed that leptin upregulated survivin mRNA and protein expression in MCF-7 breast cancer cells. Meanwhile, leptin suppressed docetaxel-induced apoptosis by inhibiting caspase activity. Knockdown of signal transducer and activator transcription 3 (STAT3) expression by small interfering RNA (siRNA) blocked leptin-induced upregulation of survivin. TransAM ELISA showed that leptin increased nuclear translocation of active STAT3. In addition, chromatin immunoprecipitation (ChIP) assay detected an enhanced binding of STAT3 to survivin promoter in MCF-7 cells after treatment by leptin. Further studies showed that leptin enhanced the transcriptional activity of survivin promoter. Collectively, our findings identify leptin/STAT3 signaling as a novel pathway for survivin expression in breast cancer cells.

  3. Identification of novel knockout and up-regulated targets for improving isoprenoid production in E. coli.

    PubMed

    Wang, Jian-feng; Meng, Hai-lin; Xiong, Zhi-qiang; Zhang, Si-liang; Wang, Yong

    2014-05-01

    Discovery of novel potential genetic targets to increase the supply of isoprenoid precursors, isopentyl/dimethylallyl diphosphate, is of importance for microbial production of isoprenoids. Here, to improve isoprenoid precursor supply, a flux distribution comparison analysis, based on the genome-scale model, was utilized to simultaneously predict the knockout, down- and up-regulated targets in Escherichia coli. 51 targets were in silico discovered. All knockout and up-regulated targets were experimentally tested to enhance lycopene production. Five knockout targets (deoB, yhfw, yahI, pta and eutD) and four up-regulated targets (ompN, ompE, ndk and cmk) led to 10-45% increases of lycopene yield, respectively, which had not been uncovered in previous studies. When engineering of the five most significant targets gdhA, eutD, tpiA, ompE and ompN, were combined the lycopene titer improved by 174% in shake-flask and 81% in bioreactor fermentations with a maximum yield of 454 mg l(-1). PMID:24658737

  4. Coral resilience to ocean acidification and global warming through pH up-regulation

    NASA Astrophysics Data System (ADS)

    McCulloch, Malcolm; Falter, Jim; Trotter, Julie; Montagna, Paolo

    2012-08-01

    Rapidly rising levels of atmospheric CO2 are not only causing ocean warming, but also lowering seawater pH hence the carbonate saturation state of the oceans, on which many marine organisms depend to calcify their skeletons. Using boron isotope systematics, we show how scleractinian corals up-regulate pH at their site of calcification such that internal changes are approximately one-half of those in ambient seawater. This species-dependent pH-buffering capacity enables aragonitic corals to raise the saturation state of their calcifying medium, thereby increasing calcification rates at little additional energy cost. Using a model of pH regulation combined with abiotic calcification, we show that the enhanced kinetics of calcification owing to higher temperatures has the potential to counter the effects of ocean acidification. Up-regulation of pH, however, is not ubiquitous among calcifying organisms; those lacking this ability are likely to undergo severe declines in calcification as CO2 levels increase. The capacity to up-regulate pH is thus central to the resilience of calcifiers to ocean acidification, although the fate of zooxanthellate corals ultimately depends on the ability of both the photosymbionts and coral host to adapt to rapidly increasing ocean temperatures.

  5. miR-1470 mediates lapatinib induced p27 upregulation by targeting c-jun.

    PubMed

    Nie, Weiwei; Song, Wei; Zhang, Wenwen; Wang, Yanru; Zhu, Aiyu; Shao, Jiaqing; Guan, Xiaoxiang

    2015-07-01

    Our previous study indicated that lapatinib induces p27-dependent G1 arrest through both transcriptional and post-translational mechanisms. Using miRNA microarray technology and quantitative RT-PCR, we further investigated the potential miRNAs that involved in p27 upregulation and Her-2 signaling pathway alteration with lapatinib treatment. A subset of 7 miRNAs was significantly affected in both 0.5?µM and 2.0?µM and 24?h and 48?h lapatinib treatment. Among them, only miR-1470, miR-126, and miR-1208 were identified in the Her-2 pathway after KEGG pathway analysis. However, luciferase reporter assay confirmed that miR-1470 directly recognized the 3'-untranslated region of c-jun transcripts, which was consistent with TargetScan analysis. miR-1470 significantly decreased c-jun expression, thus miR-1470 may repressc-jun activation of cyclinD1 expression, and consequently promoted the upregulation of p27, a key molecule in the cell cycle arrest. Taken together, the present study provided the first evidences that miR-1470 mediated lapatinib induced p27 upregulation by targeting c-jun. J. Cell. Physiol. 230: 1630-1639, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company. PMID:25545366

  6. Lipopolysaccharides upregulate hepcidin in neuron via microglia and the IL-6/STAT3 signaling pathway.

    PubMed

    Qian, Zhong-Ming; He, Xuan; Liang, Tuo; Wu, Ka-Chun; Yan, Yik-Chun; Lu, Li-Na; Yang, Guang; Luo, Qian Qian; Yung, Wing-Ho; Ke, Ya

    2014-12-01

    Neuroinflammation is closely related to brain iron homeostasis. Our previous study demonstrated that lipopolysaccharides (LPS) can regulate expression of iron-regulatory peptide hepcidin; however, the mechanism is undefined. Here, we demonstrated that intracerebroventricular injection of LPS in rat brain upregulated hepcidin and downregulated ferroportin 1 in the cortex and substantia nigra. LPS increased hepcidin expression in neurons only when they were co-cultured with BV-2 microglia, and the upregulation was suppressed by IL-6 neutralizing antibody in vitro. In addition, IL-6 but not IL-1?, IL-1?, or tumor necrosis factor-alpha increased hepcidin expression and signal transducer and activator of transcription 3 (STAT3) phosphorylation in cortical neurons and MES23.5 dopaminergic neurons. These effects were blocked by the STAT3 inhibitor, stattic. Our results show that neurons are the major source of increased hepcidin expression in response to LPS challenge but microglia play a key mediator role by releasing IL-6 and recruiting the STAT3 pathway. We conclude that LPS upregulates hepcidin expression in neurons via microglia and the IL-6/STAT3 signaling pathway. PMID:24659348

  7. Ultraviolet radiation-induced upregulation of antimicrobial proteins in health and disease.

    PubMed

    Felton, Sarah; Navid, Fatemeh; Schwarz, Agatha; Schwarz, Thomas; Gläser, Regine; Rhodes, Lesley E

    2013-01-01

    This article reviews recent data on the expression, regulation and activation of antimicrobial peptides (AMP) in human skin, and considers their potential protective and pro-inflammatory roles following upregulation by ultraviolet radiation (UVR). Antimicrobial peptides are small peptides that are key components of the innate immune system, originally identified by their vital role in protecting the body-environment interface from infection. However, it has now become clear that AMP have more extensive actions, including the provision of pivotal links with the adaptive immune system. Moreover, aberrant AMP expression may contribute to immuno-modulated inflammatory dermatoses including psoriasis, eczema and the photoaggravated condition lupus erythematosus. Recent work has demonstrated the direct upregulation of AMP in healthy skin by cutaneous UVR exposure. This may serve to protect the skin from risks imposed by both the biophysical barrier-compromise and the immunosuppression that are attributable to UVR exposure. Furthermore, it is observed that UVR provokes upregulation of AMP in an atypical manner in the photosensitivity disorder polymorphic light eruption. Dysregulated UVR responses of these pro-inflammatory proteins may play a role in the pathogenesis of certain immune-mediated diseases caused or aggravated by sunlight. PMID:22945598

  8. Ethanol-Induced Upregulation of 10-Formyltetrahydrofolate Dehydrogenase Helps Relieve Ethanol-Induced Oxidative Stress

    PubMed Central

    Hsiao, Tsun-Hsien; Lin, Chia-Jen; Chung, Yi-Shao; Lee, Gang-Hui; Kao, Tseng-Ting; Chang, Wen-Ni; Chen, Bing-Hung; Hung, Jan-Jong

    2014-01-01

    Alcoholism induces folate deficiency and increases the risk for embryonic anomalies. However, the interplay between ethanol exposure and embryonic folate status remains unclear. To investigate how ethanol exposure affects embryonic folate status and one-carbon homeostasis, we incubated zebrafish embryos in ethanol and analyzed embryonic folate content and folate enzyme expression. Exposure to 2% ethanol did not change embryonic total folate content but increased the tetrahydrofolate level approximately 1.5-fold. The expression of 10-formyltetrahydrofolate dehydrogenase (FDH), a potential intracellular tetrahydrofolate reservoir, was increased in both mRNA and protein levels. Overexpressing recombinant FDH in embryos alleviated the ethanol-induced oxidative stress in ethanol-exposed embryos. Further characterization of the zebrafish fdh promoter revealed that the ?124/+40 promoter fragment was the minimal region required for transactivational activity. The results of site-directed mutagenesis and binding analysis revealed that Sp1 is involved in the basal level of expression of fdh but not in ethanol-induced upregulation of fdh. On the other hand, CEBP? was the protein that mediated the ethanol-induced upregulation of fdh, with an approximately 40-fold increase of fdh promoter activity when overexpressed in vitro. We concluded that upregulation of fdh involving CEBP? helps relieve embryonic oxidative stress induced by ethanol exposure. PMID:24277932

  9. Statins Decrease Lung Inflammation in Mice by Upregulating Tetraspanin CD9 in Macrophages

    PubMed Central

    Jin, Yingji; Tachibana, Isao; Takeda, Yoshito; He, Ping; Kang, Sujin; Suzuki, Mayumi; Kuhara, Hanako; Tetsumoto, Satoshi; Tsujino, Kazuyuki; Minami, Toshiyuki; Iwasaki, Takeo; Nakanishi, Kaori; Kohmo, Satoshi; Hirata, Haruhiko; Takahashi, Ryo; Inoue, Koji; Nagatomo, Izumi; Kida, Hiroshi; Kijima, Takashi; Ito, Mari; Saya, Hideyuki; Kumanogoh, Atsushi

    2013-01-01

    Tetraspanins organize protein complexes in tetraspanin-enriched membrane microdomains that are distinct from lipid rafts. Our previous studies suggested that reduction in the levels of tetraspanins CD9 and CD81 may be involved in the progression of inflammatory lung diseases, especially COPD. To search for agents that increase the levels of these tetraspanins, we screened 1,165 drugs in clinical use and found that statins upregulate CD9 and CD81 in RAW264.7 macrophages. The lipophilic statins, fluvastatin and simvastatin, reversed LPS-induced downregulation of CD9 and CD81, simultaneously preventing TNF-? and matrix metalloproteinase-9 production and spreading of RAW264.7 cells. These statins exerted anti-inflammatory effects in vitro in wild-type macrophages but not in CD9 knockout macrophages, and decreased lung inflammation in vivo in wild-type mice but not in CD9 knockout mice, suggesting that their effects are dependent on CD9. Mechanistically, the statins promoted reverse transfer of the LPS-signaling mediator CD14 from lipid rafts into CD9-enriched microdomains, thereby preventing LPS receptor formation. Finally, upregulation of CD9/CD81 by statins was related to blockade of GTPase geranylgeranylation in the mevalonate pathway. Our data underscore the importance of the negative regulator CD9 in lung inflammation, and suggest that statins exert anti-inflammatory effects by upregulating tetraspanin CD9 in macrophages. PMID:24040034

  10. Argipressin(4-8) upregulate CTP: phosphocholine cytidylyltransferase in rat hippocampal neurons.

    PubMed

    Xu, Kan-Yan; Xiong, Ying; Du, Yu-Cang

    2002-07-01

    In order to study the effect of argipressin(4-8)(AVP(4-8)) on the mRNA level and activity of cytidine triphosphate: phosphocholine cytidylyltransferase(CCT) in rat hippocampal neurons, and elucidate it's possible mechanism. Rat hippocampal neurons treated with AVP(4-8) or actinomycin D were incubated with different time periods. The mRNA level of CCT was detected using RT-PCR plus Southern blot, CCT activity was determined by measuring the rate of incorporation of (14)C - phosphocholine into cytidine diphosphate-choline(CDP-choline). It was found that AVP4-8 could upregulate the CCT mRNA in rat hippocampal neurons. ZDC(C)PR, the antagonist of AVP(4-8), could greatly inhibit this upregulation. Using actinomycin D to inhibite the eucaryotic transcription, it was found that the halflife of CCT mRNA could be prolonged by coincubation with AVP(4-8). Meanwhile, AVP(4-8) could also increase CCT activity in rat hippocampal neurons. These results demonstrated that AVP(4-8) upregulated CCT mRNA level and its activity through stabilizing the CCT mRNA in rat hippocampal neurons. PMID:12098762

  11. Stromal fibroblasts in the microenvironment of gastric carcinomas promote tumor metastasis via upregulating TAGLN expression

    PubMed Central

    2013-01-01

    Background Fibroblasts play a critical role in tumorigenesis, tumor progression and metastasis. However, their detailed molecular characteristics and clinical significance are still elusive. TAGLN is an actin-binding protein that plays an important role in tumorigenesis. Results We investigated the interaction between cancer cells and the tumor microenvironment to determine how the fibroblasts from human gastric carcinoma facilitate tumorigenesis through TAGLN. QRT-PCR and Western blot indicated that TAGLN expression was upregulated in gastric carcinoma-associated fibroblasts (CAFs) that promote gastric cancer cell migration and invasion. Using small interfering RNA (siRNA), we found that CAFs enhanced tumor metastasis through upregulated TAGLN in vitro and in vivo. The expression of matrix metalloproteinase-2 (MMP-2) was significantly lower after TAGLN knock-down by siRNA. TAGLN levels were elevated in human gastric cancer stroma than normal gastric stroma and associated with differentiation and lymph node metastasis of gastric cancer. Conclusion CAFs may promote gastric cancer cell migration and invasion via upregulating TAGLN and TAGLN induced MMP-2 production. PMID:23510049

  12. Hyaluronan up-regulation is linked to renal dysfunction and hearing loss induced by silver nanoparticles.

    PubMed

    Feng, Hao; Pyykkö, Ilmari; Zou, Jing

    2014-08-01

    Increased application of silver nanoparticles (AgNPs) has raised concerns on their potential adverse effects on human health. However, the precise toxicological mechanisms are not known in detail. The current study hypothesized that AgNPs induced glycosaminoglycan accumulation in the basement membrane that associated with the up-regulation of its component hyaluronic acid, known as a hydrophilic molecule of binding and retaining water, and caused toxicities in the kidney and cochlea. Rats administered AgNPs through either intravenous or intratympanic injection were observed at different time points after exposure. The concentrations of creatinine and urea in the serum were elevated remarkably, and proteins leaked into the urine were increased. A significant hearing loss over a broad range of frequencies was indicated. AgNP exposure induced glycosaminoglycan accumulation and hyaluronic acid up-regulation in the basement membrane. Abundant apoptotic cell death was demonstrated in the AgNP-exposed organs. Our results suggested that glycosaminoglycan accumulation associated with the up-regulation of hyaluronic acid was involved in the toxicities of kidney and cochlea caused by AgNPs. PMID:25082176

  13. Hydrogen peroxide and coffee induce G:C-->T:A transversions in the lacI gene of catalase-defective Escherichia coli.

    PubMed

    Ruiz-Laguna, J; Pueyo, C

    1999-01-01

    The mutagenicity of hydrogen peroxide (H2O2) was compared with that of coffee, a complex mixture which generates H2O2. An Escherichia coli strain defective in catalase activity (katG katE double mutant) and carrying a single copy mucAB (pRW144) plasmid was constructed to enhance the mutagenic response to oxidants. The ability of the mucAB genes to influence the type, frequency and distribution of H2O2-induced mutations was also investigated in isogenic bacteria lacking pRW144. Induced mutational spectra were characterized and compared with that of spontaneous mutagenesis. A total of 444 independent forward mutations affecting the first 210 bp of the lacI gene were identified by DNA sequence analysis. The spontaneous mutation spectrum showed no bias (P = 0.52) for substitutions at G:C base pairs. In contrast, in the H2O2-induced spectrum substitutions occurred preferentially at G:C base pairs (P < 0.0001) with a preponderance of G:C-->T:A transversions (43.4% of H2O2-induced mutants versus 17.3% of spontaneous mutants). These data support the view that 7,8-dihydro-8-oxoguanine is the main premutagenic lesion induced by H2O2 and that catalase-defective bacteria have elevated levels of 8-oxoguanine in chromosome DNA after H2O2 exposure. Coffee produced a similar distribution of mutational events as H2O2 (P > 0.05), suggesting that this compound may be the main cause of the coffee-induced mutagenesis. The presence of plasmid pRW144 did not affect the frequency of H2O2-induced G:C-->T:A transversions, but caused an increase in A:T-->T:A transversions and a decrease in -1 base frameshifts. Although the frequencies of G:C-->T:A transversions were similar in all three induced spectra (H2O2 and coffee +/- pRW144), differences were observed in location of mutations throughout the target gene. PMID:10474829

  14. Mitochondria-targeted catalase reduces abnormal APP processing, amyloid ? production and BACE1 in a mouse model of Alzheimer's disease: implications for neuroprotection and lifespan extension

    PubMed Central

    Mao, Peizhong; Manczak, Maria; Calkins, Marcus J.; Truong, Quang; Reddy, Tejaswini P.; Reddy, Arubala P.; Shirendeb, Ulziibat; Lo, Herng-Hsiang; Rabinovitch, Peter S.; Reddy, P. Hemachandra

    2012-01-01

    The purpose of this study was to investigate the protective effects of the mitochondria-targeted antioxidant catalase (MCAT) and lifespan extension in mice that express amyloid beta (A?). Using immunoblotting and immunostaining analyses, we measured the production of full-length amyloid precursor protein (APP), soluble APP?, C-terminal fragments CTF99 and CTF83, monomeric and oligomeric A?, A? deposits and beta site amyloid precursor protein cleaving enzyme 1 (BACE1), in different stages of disease progression in MCAT/A?PP and A?PP mice. Using quantitative reverse transcriptase polymerase chain reaction and immunostaining analyses, we studied the expression of catalase, BACE1, the Alzheimer's disease (AD) markers, synaptophysin, APP, neprilysin, insulin-degrading enzyme and transthyretin in MCAT, A?PP, MCAT/A?PP and wild-type (WT) mice. Using the high pressure liquid chromatography analysis of 8-hydroxy-2-deoxyguanosine, we measured oxidative DNA damage in the cerebral cortical tissues from MCAT, A?PP, MCAT/A?PP and WT mice. We found that the A?PP transgenic mice that carried the human MCAT gene lived 5 months longer than did the A?PP mice. We also found that the overexpression of MCAT in the brain sections from the MCAT/A?PP transgenic mice significantly correlated with a reduction in the levels of full-length APP, CTF99, BACE1, A? levels (40 and 42), A? deposits and oxidative DNA damage relative to the brain sections from the A?PP mice. Interestingly, we found significantly increased levels of soluble APP? and CTF83 in the MCAT/A?PP mice, relative to the A?PP mice. These data provide direct evidence that oxidative stress plays a primary role in AD etiopathology and that in MCAT mice express A?, MCAT prevents abnormal APP processing, reduces A? levels and enhances A?-degrading enzymes in mice at different ages, corresponding to different stages of disease progression. These findings indicate that mitochondria-targeted molecules may be an effective therapeutic approach to treat patients with AD. PMID:22492996

  15. Role of ROCK upregulation in endothelial and smooth muscle vascular functions in diabetic rat aorta

    PubMed Central

    2013-01-01

    Background The RhoA/ROCK signaling pathway mediates vascular smooth muscle contraction while endogenous NO induces vasodilation through its inhibition. Since myosin light chain phosphatase (MLCP) and eNOS are targeted by RhoA/ROCK upregulation then turn to lead abnormalities in vasculature, we aimed to examine whether less endothelial NO-production and inhibited eNOS together with an upregulation of RhoA/ROCK signaling pathway in thoracic aorta can play an important role in vascular dysfunction under hyperglycemia. Methods We used streptozotocin-injected rats, as a model of type 1 diabetes, and their lean controls to investigate the role of ROCK upregulation in the function of toracic aorta by using electrophysiological and biochemical techniques. Results The protein level of ROCK isoform ROCK2 was found to be 2.5-fold higher in endothelium-intact aortic rings of the diabetic rats compared to those of the controls while its level in endothelium-denuded rings was similar among these two groups. Phosphorylation level of eNOS in endothelium-intact rings from the diabetics was 50% less compared to that of the control. ROCK inhibitors, either Y27632 or HA1077, induced concentration-dependent relaxation with a marked left-shift in phenylephrine pre-contracted endothelium-intact rings from either diabetics or high glucose incubated controls while pretreatment of these rings with L-NAME abolished this shift, fully. Moreover, phosphorylation levels of both MLCP and MLC in endothelium-denuded rings were markedly higher in the diabetics than the controls. Conclusion We demonstrated that diabetes-induced vascular dysfunction can arise due to either inbition of eNOS, thereby less endothelial NO-production, either directly or indirectly, in part, due to an upregulation of ROCK2 by hyperglycemia. Additionally, our data demonstrate that high phosphorylation levels of both MLC and MLCP in endothelium-denuded rings can be due to a less endothelial NO-production dependent ROCK upregulation in the smooth muscle cells under hyperglycemia, as well. PMID:23530857

  16. Shikonin inhibits oxidized LDL-induced monocyte adhesion by suppressing NF?B activation via up-regulation of PI3K/Akt/Nrf2-dependent antioxidation in EA.hy926 endothelial cells.

    PubMed

    Huang, Chin-Shiu; Lin, Ai-Hsuan; Yang, Ting-Chun; Liu, Kai-Li; Chen, Haw-Wen; Lii, Chong-Kuei

    2015-02-01

    Oxidized low-density lipoprotein (oxLDL) is a key contributor to atherogenesis through multiple mechanisms, including the reactive oxygen species (ROS)-mediated nuclear factor-kappaB (NF?B) signaling pathway. Although shikonin, one of the main active components isolated from the Chinese herb Lithospermum erythrorhizon, has been shown to possess cardioprotective, antioxidative, and anti-inflammatory effects, the mechanisms underlying these actions are not well understood. In this study, we used EA.hy926 endothelial-like cells to examine the anti-atherogenic activity of shikonin. Shikonin (0-1 ?M) concentration-dependently induced heme oxygenase-1, glutamate cysteine ligase modifier subunit, catalase, superoxide dismutase 1, glutathione peroxidase 1, and glutathione reductase protein and mRNA expression and glutathione content via activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/Nrf2 signaling pathway. In the presence of oxLDL (40 ?g/ml), shikonin pretreatment reversed oxLDL-induced ROS production, antioxidant response element reporter activity, NF?B nuclear translocation, and intercellular adhesion molecule (ICAM)-1 and E-selectin expression and suppressed the increase of monocyte adhesion to endothelial cells. Nrf2 knockdown by using RNA interference attenuated the ability of shikonin to inhibit oxLDL-induced NF?B DNA binding activity, adhesion molecule expression, and monocyte adhesion. Taken together, these results suggest that shikonin protects against oxLDL-induced endothelial damage by suppressing ROS/NF?B-mediated ICAM-1 and E-selectin expression via up-regulation of PI3K/Akt/Nrf2-dependent antioxidant enzyme expression. PMID:25541286

  17. Modulation of the Activities of Catalase, Cu-Zn, Mn Superoxide Dismutase, and Glutathione Peroxidase in Adipocyte from Ovariectomised Female Rats with Metabolic Syndrome

    PubMed Central

    Guerra, Rebeca Cambray; Zuñiga-Muñoz, Alejandra; Guarner Lans, Verónica; Díaz-Díaz, Eulises; Tena Betancourt, Carlos Alberto; Pérez-Torres, Israel

    2014-01-01

    The aim of this study was to evaluate the association between estrogen removal, antioxidant enzymes, and oxidative stress generated by obesity in a MS female rat model. Thirty two female Wistar rats were divided into 4 groups: Control (C), MS, MS ovariectomized (Ovx), and MS Ovx plus estradiol (E2). MS was induced by administering 30% sucrose to drinking water for 24 weeks. After sacrifice, intra-abdominal fat was dissected; adipocytes were isolated and lipid peroxidation, non-enzymatic antioxidant capacity, and the activities of Cu-Zn and Mn superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined. There were no significant differences in the activities of Cu-Zn, Mn SOD, CAT, and GPx between the C and MS groups, but in the MS Ovx group there was a statistically significant decrease in the activities of these enzymes when compared to MS and MS Ovx+E2. The increased lipid peroxidation and nonenzymatic antioxidant capacity found in MS Ovx was significantly decreased when compared to MS and MS Ovx+E2. In conclusion, the removal of E2 by ovariectomy decreases the activity of the antioxidant enzymes in the intra-abdominal tissue of MS female rats; this is reflected by increased lipid peroxidation and decreased nonenzymatic antioxidant capacity. PMID:24987414

  18. RNAi-Mediated Knockdown of Catalase Causes Cell Cycle Arrest in SL-1 Cells and Results in Low Survival Rate of Spodoptera litura (Fabricius)

    PubMed Central

    Hu, Meiying; Chen, Shaohua; Muhammad, Rizwan-ul-Haq; Dong, Xiaolin; Gong, Liang

    2013-01-01

    Deregulated reactive oxygen species (ROS) production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT) is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444) was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT). This study implied that ROS scavenging by CAT is important for S. litura survival. PMID:23555693

  19. Induction of the Viable but Nonculturable State of Ralstonia solanacearum by Low Temperature in the Soil Microcosm and Its Resuscitation by Catalase

    PubMed Central

    Kong, Hyun Gi; Bae, Ju Young; Lee, Hyoung Ju; Joo, Hae Jin; Jung, Eun Joo; Chung, Eunsook; Lee, Seon-Woo

    2014-01-01

    Ralstonia solanacearum is the causal agent of bacterial wilt on a wide variety of plants, and enters a viable but nonculturable (VBNC) state under stress conditions in soil and water. Here, we adopted an artificial soil microcosm (ASM) to investigate the VBNC state of R. solanacearum induced by low temperature. The culturability of R. solanacearum strains SL341 and GMI1000 rapidly decreased at 4°C in modified ASM (mASM), while it was stably maintained at 25°C in mASM. We hypothesized that bacterial cells at 4°C in mASM are viable but nonculturable. Total protein profiles of SL341 cells at 4°C in mASM did not differ from those of SL341 culturable cells at 25°C in mASM. Moreover, the VBNC cells maintained in the mASM retained respiration activity. Catalase treatment effectively restored the culturability of nonculturable cells in mASM, while temperature increase or other treatments used for resuscitation of other bacteria were not effective. The resuscitated R. solanacearum from VBNC state displayed normal level of bacterial virulence on tomato plants compared with its original culturable bacteria. Expression of omp, oxyR, rpoS, dps, and the 16S rRNA gene quantified by RT-qPCR did not differ significantly between the culturable and VBNC states of R. solanacearum. Our results suggested that the VBNC bacterial cells in mASM induced by low temperature exist in a physiologically unique state. PMID:25296177

  20. Erythrocyte superoxide dismutase, glutathione peroxidase, and catalase activities and risk of coronary heart disease in generally healthy women: a prospective study.

    PubMed

    Yang, Shuman; Jensen, Majken K; Rimm, Eric B; Willett, Walter; Wu, Tianying

    2014-11-01

    Erythrocyte antioxidant enzymes are major circulating antioxidant enzymes in the oxidative stress defense system. Few prospective studies have assessed the association between these enzymes and the risk of coronary heart disease (CHD) in generally healthy adults. We conducted a prospective nested case-control study of CHD among 32,826 women at baseline with 15 years of follow-up from 1989 to 2004 in the Nurses' Health Study. We investigated the association of baseline erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities with the risk of CHD. A total of 365 cases and 728 controls were included in the analysis. Overall, the relative risks of CHD associated with 1-standard deviation higher SOD, GPx, and CAT activities were 1.07 (95% confidence interval (CI): 0.94, 1.22), 1.04 (95% CI: 0.91, 1.18), and 1.04 (95% CI: 0.92, 1.17), respectively. Multivariable adjustments did not change the associations appreciably. Fasting status did not modify the associations, with the exception that SOD activity was positively associated with the risk of CHD among participants who provided blood samples within 12 hours of fasting. Overall, activities of SOD, GPx, and CAT were not associated with CHD among women who were generally healthy at the time of blood collection. PMID:25156995

  1. Catalase-like activity of bovine met-hemoglobin: interaction with the pseudo-catalytic peroxidation of anthracene traces in aqueous medium.

    PubMed

    Paco, Laveille; Galarneau, Anne; Drone, Jullien; Fajula, François; Bailly, Carole; Pulvin, Sylviane; Thomas, Daniel

    2009-10-01

    Hemoglobin is a member of the hemoprotein superfamily whose main role is to transport O(2) in vertebrate organisms. It has two known promiscuous enzymatic activities, peroxidase and oxygenase. Here we show for the first time that bovine hemoglobin also presents a catalase-like activity characterized by a V(max )of 344 microM/min, a K(M )of 24 mM and a k(cat) equal to 115/min. For high anthracene and hemoglobin concentrations and low hydrogen peroxide concentrations, this activity inhibits the expected oxidation of anthracene, which occurs through a peroxidase-like mechanism. Anthracene belongs to the polycyclic aromatic hydrocarbon (PAH) family whose members are carcinogenic and persistent pollutants found in industrial waste waters. Our results show that anthracene oxidation by hemoglobin and hydrogen peroxide follows a typical bi-bi ping-pong mechanism with a V(max) equal to 0.250 microM/min, K(M(H2O2) )of 80 microM, K(M(ANT)) of 1.1 microM and k(cat) of 0.17/min. The oxidation of anthracene is shown to be pseudo-catalytic because an excess of hemoglobin and hydrogen peroxide is required to make PAH completely disappear. Thus, bovine hemoglobin presents, in different degrees, all the catalytic activities of the hemoprotein group, which makes it a very interesting protein for biotechnological processes and one with which structure-activity relationships can be studied. PMID:19606432

  2. Short-Term Treatment with a SOD/Catalase Mimetic, EUK-207, Mitigates Pneumonitis and Fibrosis after Single-Dose Total-Body or Whole-Thoracic Irradiation

    PubMed Central

    Gao, Feng; Fish, Brian L.; Szabo, Aniko; Doctrow, Susan R.; Kma, Lakhan; Molthen, Robert C.; Moulder, John E.; Jacobs, Elizabeth R.; Medhora, Meetha

    2013-01-01

    In the event of a radiological accident or terrorist attack, whole- or partial-body exposure can injure the lungs. To simulate such an incident, we used a single fraction of total-body irradiation (TBI) or whole-thoracic irradiation to induce pneumonitis or pulmonary fibrosis, respectively, in a rat model. The superoxide dismutase and catalase mimetic EUK-207 was given by subcutaneous injection (20 mg/kg/day, 5 days per week, once daily) starting at 7 days after irradiation and stopping before pneumonitis developed. After TBI, morbidity and the increase in breathing rates associated with pneumonitis were significantly improved in rats treated with EUK-207 compared to rats receiving irradiation alone. At 42 days after TBI (the peak of pneumonitis) changes in vascular end points including pulmonary hemodynamics ex vivo and relative arterial density in lungs were also mitigated by EUK-207. At 7 months after whole-thoracic irradiation, EUK-207 reduced synthesis of collagen as assessed by the Sircol collagen assay and Masson’s trichrome staining. Our results demonstrate promise for EUK-207 as a mitigator of radiation pneumonitis and fibrosis. We also demonstrate for the first time mitigation of multiple vascular injuries in the irradiated lung in vivo by EUK-207. PMID:23020094

  3. The Mycobacterial LysR-Type Regulator OxyS Responds to Oxidative Stress and Negatively Regulates Expression of the Catalase-Peroxidase Gene

    PubMed Central

    Li, Yuqing; He, Zheng-Guo

    2012-01-01

    Protection against oxidative stress is one of the primary defense mechanisms contributing to the survival of Mycobacterium tuberculosis in the host. In this study, we provide evidence that OxyS, a LysR-type transcriptional regulator functions as an oxidative stress response regulator in mycobacteria. Overexpression of OxyS lowers expression of the catalase-peroxidase (KatG) gene in M. smegmatis. OxyS binds directly with the katG promoter region and a conserved, GC-rich T-N11-A motif for OxyS binding was successfully characterized in the core binding site. Interestingly, the DNA-binding activity of OxyS was inhibited by H2O2, but not by dithiothreitol. Cys25, which is situated at the DNA-binding domain of OxyS, was found to have a regulatory role for the DNA-binding ability of OxyS in response to oxidative stress. In contrast, the other three cysteine residues in OxyS do not appear to have this function. Furthermore, the mycobacterial strain over-expressing OxyS had a higher sensitivity to H2O2.Thus, OxyS responds to oxidative stress through a unique cysteine residue situated in its DNA-binding domain and negatively regulates expression of the katG gene. These findings uncover a specific regulatory mechanism for mycobacterial adaptation to oxidative stress. PMID:22272299

  4. Catalase overexpression prevents nuclear factor erythroid 2-related factor 2 stimulation of renal angiotensinogen gene expression, hypertension, and kidney injury in diabetic mice.

    PubMed

    Abdo, Shaaban; Shi, Yixuan; Otoukesh, Abouzar; Ghosh, Anindya; Lo, Chao-Sheng; Chenier, Isabelle; Filep, Janos G; Ingelfinger, Julie R; Zhang, Shao Ling; Chan, John S D

    2014-10-01

    This study investigated the impact of catalase (Cat) overexpression in renal proximal tubule cells (RPTCs) on nuclear factor erythroid 2-related factor 2 (Nrf2) stimulation of angiotensinogen (Agt) gene expression and the development of hypertension and renal injury in diabetic Akita transgenic mice. Additionally, adult male mice were treated with the Nrf2 activator oltipraz with or without the inhibitor trigonelline. Rat RPTCs, stably transfected with plasmid containing either rat Agt or Nrf2 gene promoter, were also studied. Cat overexpression normalized systolic BP, attenuated renal injury, and inhibited RPTC Nrf2, Agt, and heme oxygenase-1 (HO-1) gene expression in Akita Cat transgenic mice compared with Akita mice. In vitro, high glucose level, hydrogen peroxide, and oltipraz stimulated Nrf2 and Agt gene expression; these changes were blocked by trigonelline, small interfering RNAs of Nrf2, antioxidants, or pharmacological inhibitors of nuclear factor-?B and p38 mitogen-activated protein kinase. The deletion of Nrf2-responsive elements in the rat Agt gene promoter abolished the stimulatory effect of oltipraz. Oltipraz administration also augmented Agt, HO-1, and Nrf2 gene expression in mouse RPTCs and was reversed by trigonelline. These data identify a novel mechanism, Nrf2-mediated stimulation of intrarenal Agt gene expression and activation of the renin-angiotensin system, by which hyperglycemia induces hypertension and renal injury in diabetic mice. PMID:24812425

  5. Disruption of AtWNK8 Enhances Tolerance of Arabidopsis to Salt and Osmotic Stresses via Modulating Proline Content and Activities of Catalase and Peroxidase

    PubMed Central

    Zhang, Baige; Liu, Kaidong; Zheng, Yan; Wang, Yingxiang; Wang, Jinxiang; Liao, Hong

    2013-01-01

    With no lysine kinases (WNKs) play important roles in plant growth and development. However, its role in salt and osmotic stress tolerance is unclear. Here, we report that AtWNK8 is mainly expressed in primary root, hypocotyl, stamen and pistil and is induced by NaCl and sorbitol treatment. Compared to the wild-type, the T-DNA knock-out wnk8 mutant was more tolerant to severe salinity and osmotic stresses, as indicated by 27% and 198% more fresh weight in the NaCl and sorbitol treatment, respectively. The wnk8 mutant also accumulated 1.43-fold more proline than the wild-type in the sorbitol treatment. Under NaCl and sorbitol stresses, catalase (CAT) activity in wnk8 mutant was 1.92- and 3.7-times of that in Col-0, respectively. Similarly, under salt and osmotic stress conditions, peroxidase (POD) activities in wnk8 mutant were 1.81- and 1.58-times of that in Col-0, respectively. Taken together, we revealed that maintaining higher CAT and POD activities might be one of the reasons that the disruption of AtWNK8 enhances the tolerance to salt stress, and accumulating more proline and higher activities of CAT and POD might result in the higher tolerance of WNK8 to osmotic stress. PMID:23535337

  6. A mimic of phosphorylated prolactin inhibits human breast cancer cell proliferation via upregulation of p21 waf1

    Microsoft Academic Search

    Wenjie Xie; Yan He; Da Huo; Yafang Huang; Wei Wu

    2010-01-01

    A mimic of phosphorylated prolactin (S179D PRL) inhibits mouse normal mammary HC11 cell proliferation through the upregulation\\u000a of the vitamin D receptor (VDR) and p21. Here, we investigated whether S179D PRL also inhibited growth of human breast cancer\\u000a MCF7 cells via VDR and p21. Western blots showed that S179D PRL upregulated VDR and p21 after the cells were incubated with

  7. Insecticide-Mediated Up-Regulation of Cytochrome P450 Genes in the Red Flour Beetle (Tribolium castaneum)

    PubMed Central

    Liang, Xiao; Xiao, Da; He, Yanping; Yao, Jianxiu; Zhu, Guonian; Zhu, Kun Yan

    2015-01-01

    Some cytochrome P450 (CYP) genes are known for their rapid up-regulation in response to insecticide exposures in insects. To date, however, limited information is available with respect to the relationships among the insecticide type, insecticide concentration, exposure duration and the up-regulated CYP genes. In this study, we examined the transcriptional response of eight selected CYP genes, including CYP4G7, CYP4Q4, CYP4BR3, CYP12H1, CYP6BK11, CYP9D4, CYP9Z5 and CYP345A1, to each of four insecticides in the red flour beetle, Tribolium castaneum. Reverse transcription quantitative PCR (RT-qPCR) revealed that CYP4G7 and CYP345A1 can be significantly up-regulated by cypermethrin (1.97- and 2.06-fold, respectively), permethrin (2.00- and 2.03-fold) and lambda-cyhalothrin (1.73- and 1.81-fold), whereas CYP4BR3 and CYP345A1 can be significantly up-regulated by imidacloprid (1.99- and 1.83-fold) when 20-day larvae were exposed to each of these insecticides at the concentration of LC20 for 24 h. Our studies also showed that similar levels of up-regulation can be achieved for CYP4G7, CYP4BR3 and CYP345A1 by cypermethrin, permethrin, lambda-cyhalothrin or imidacloprid with approximately one fourth of LC20 in 6 h. Our study demonstrated that up-regulation of these CYP genes was rapid and only required low concentrations of insecticides, and the up-regulation not only depended on the CYP genes but also the type of insecticides. Our results along with those from previous studies also indicated that there were no specific patterns for predicting the up-regulation of specific CYP gene families based on the insecticide classification. PMID:25607733

  8. PBK\\/TOPK Is a Novel Mitotic Kinase Which Is Upregulated in Burkitt's Lymphoma and Other Highly Proliferative Malignant Cells

    Microsoft Academic Search

    Michelle Simons-Evelyn; Kim Bailey-Dell; Jeffrey A. Toretsky; Douglas D. Ross; Robert Fenton; Dhan Kalvakolanu; Aaron P. Rapoport

    2001-01-01

    ABSTRACTPBK\\/TOPK is a recently cloned serine\\/threonine kinase which is phosphorylated during mitosis. Earlier work indicated that this kinase is upregulated in a Burkitt's lymphoma cell line (GA-10). To determine whether PBK\\/TOPK is upregulated in other mitotically active neoplastic cell lines and tissues, Northern analysis was performed on a panel of malignant cell lines and on clinical samples from patients with

  9. Insecticide-mediated up-regulation of cytochrome P450 genes in the red flour beetle (Tribolium castaneum).

    PubMed

    Liang, Xiao; Xiao, Da; He, Yanping; Yao, Jianxiu; Zhu, Guonian; Zhu, Kun Yan

    2015-01-01

    Some cytochrome P450 (CYP) genes are known for their rapid up-regulation in response to insecticide exposures in insects. To date, however, limited information is available with respect to the relationships among the insecticide type, insecticide concentration, exposure duration and the up-regulated CYP genes. In this study, we examined the transcriptional response of eight selected CYP genes, including CYP4G7, CYP4Q4, CYP4BR3, CYP12H1, CYP6BK11, CYP9D4, CYP9Z5 and CYP345A1, to each of four insecticides in the red flour beetle, Tribolium castaneum. Reverse transcription quantitative PCR (RT-qPCR) revealed that CYP4G7 and CYP345A1 can be significantly up-regulated by cypermethrin (1.97- and 2.06-fold, respectively), permethrin (2.00- and 2.03-fold) and lambda-cyhalothrin (1.73- and 1.81-fold), whereas CYP4BR3 and CYP345A1 can be significantly up-regulated by imidacloprid (1.99- and 1.83-fold) when 20-day larvae were exposed to each of these insecticides at the concentration of LC20 for 24 h. Our studies also showed that similar levels of up-regulation can be achieved for CYP4G7, CYP4BR3 and CYP345A1 by cypermethrin, permethrin, lambda-cyhalothrin or imidacloprid with approximately one fourth of LC20 in 6 h. Our study demonstrated that up-regulation of these CYP genes was rapid and only required low concentrations of insecticides, and the up-regulation not only depended on the CYP genes but also the type of insecticides. Our results along with those from previous studies also indicated that there were no specific patterns for predicting the up-regulation of specific CYP gene families based on the insecticide classification. PMID:25607733

  10. Receptor-interacting Protein 1 Increases Chemoresistance by Maintaining Inhibitor of Apoptosis Protein Levels and Reducing Reactive Oxygen Species through a microRNA-146a-mediated Catalase Pathway*

    PubMed Central

    Wang, Qiong; Chen, Wenshu; Bai, Lang; Chen, Wenjie; Padilla, Mabel T.; Lin, Amy S.; Shi, Shaoqing; Wang, Xia; Lin, Yong

    2014-01-01

    Although receptor-interacting protein 1 (RIP1) is well known as a key mediator in cell survival and death signaling, whether RIP1 directly contributes to chemotherapy response in cancer has not been determined. In this report, we found that, in human lung cancer cells, knockdown of RIP1 substantially increased cytotoxicity induced by the frontline anticancer therapeutic drug cisplatin, which has been associated with robust cellular reactive oxygen species (ROS) accumulation and enhanced apoptosis. Scavenging ROS dramatically protected RIP1 knockdown cells against cisplatin-induced cytotoxicity. Furthermore, we found that, in RIP1 knockdown cells, the expression of the hydrogen peroxide-reducing enzyme catalase was dramatically reduced, which was associated with increased miR-146a expression. Inhibition of microRNA-146a restored catalase expression, suppressed ROS induction, and protected against cytotoxicity in cisplatin-treated RIP1 knockdown cells, suggesting that RIP1 maintains catalase expression to restrain ROS levels in therapy response in cancer cells. Additionally, cisplatin significantly triggered the proteasomal degradation of cellular inhibitor of apoptosis protein 1 and 2 (c-IAP1 and c-IAP2), and X-linked inhibitor of apoptosis (XIAP) in a ROS-dependent manner, and in RIP1 knockdown cells, ectopic expression of c-IAP2 attenuated cisplatin-induced cytotoxicity. Thus, our results establish a chemoresistant role for RIP1 that maintains inhibitor of apoptosis protein (IAP) expression by release of microRNA-146a-mediated catalase suppression, where intervention within this pathway may be exploited for chemosensitization. PMID:24425875

  11. The C1167T polymorphism of the catalase gene and polymorphic markers D11S907 and D11S2008 located in its vicinity are associated with diabetes mellitus type 2

    Microsoft Academic Search

    D. A. Chistyakov; K. V. Savost’yanov; R. I. Turakulov; L. N. Scherbacheva; G. G. Mamaeva; M. I. Balabolkin; V. V. Nosikov

    2000-01-01

    To study the contribution of the catalase (CAT) gene in diabetes mellitus (DM) type 2, the allele and genotype frequencies\\u000a of internal (polymorphism C1167T) and two neighboring (minisatellites D11S907 and D11S2008) polymorphic markers were studied\\u000a in 132 healthy individuals and 154 patients from Moscow. Allele C and genotype CC of the C1167T polymorphism proved associated\\u000a with a higher risk of

  12. Androgen deprivation therapy induces androgen receptor-dependent upregulation of Egr1 in prostate cancers

    PubMed Central

    Xu, Bin; Tang, Gusheng; Xiao, Chengwu; Wang, Linhui; Yang, Qing; Sun, Yinghao

    2014-01-01

    Early growth response gene-1 (Egr1) has a crucial function in the development and progression of prostate cancer. However, whether Egr1 contributes to the transition of advanced androgen-independent prostate cancer (AIPC) from androgen-dependent prostate cancer (ADPC) remains largely unknown. To the best of our knowledge, through immunohistochemical staining methods, we were the first to identify that Egr1 is more highly expressed in AIPC clinical specimens than in androgen-dependent prostate cancer (ADPC). An in vitro study with quantitative RT-PCR and Western blot demonstrated that Egr1 also has a higher expression in androgen-independent PC3 cells than in the androgen-dependent LNCaP cells. Egr1 expression in LNCaP cells was significantly upregulated during the androgen deprivation treatment (ADT) and was re-downregulated through the addition of dihydrotestosterone. Although no variation in PC3 cells was identified, Egr1 responded to dihydrotestosterone and flutamide in the androgen receptor (AR)-transfected PC3 cells. Further investigation with Egr1 agonist and specific siRNA-targeting Egr1 revealed that Egr1 upregulation or downregulation was accompanied by a change in inhibitors of differentiation and DNA binding-1 (Id1) in the same direction in both LNCaP and PC3 cells. The variation is shown to be negatively regulated by androgen through AR during ADT. Our data suggested that upregulated Egr1 might partially contribute to the emergence of AIPC after prolonged ADT. This study also elucidated the potential mechanism underlying Id1 participation in the progression of prostate cancer. Understanding the key molecular events in the transition from ADPC to AIPC may provide new therapeutic intervention strategies for patients with AIPC. PMID:25031707

  13. BNIP3 upregulation by ERK and JNK mediates cadmium-induced necrosis in neuronal cells.

    PubMed

    Wang, Bin; Xiao, Jia-Li; Ling, Yi-Hui; Meng, Xiao-Jing; Wu, Bing; Yang, Xin-Yi; Zou, Fei

    2014-08-01

    Cadmium (Cd) is a toxic heavy metal that may cause neurological disorders. We studied the mechanism underlying Cd-mediated cell death in neuronal cells. In Cd-induced neurotoxicity, caspase-3 was only modestly activated, and accordingly, zVAD-fmk, a pan-caspase inhibitor, partially attenuated cell death. However, pretreatment with Necrox-2 or Necrox-5, two novel necrosis inhibitors, suppressed cell death more markedly compared with pretreatment with zVAD-fmk. Moreover, the necrosis inhibitors did not prevent cleavage of caspase-3. These results indicate that caspase-independent necrosis is more prevalent in Cd-induced neurotoxicity. Bcl-2 and adenovirus E1B-19 kDa-interacting protein 3 (BNIP3) has been reported to be related to caspase-independent cell death. Cd treatment caused a dramatic upregulation of BNIP3 mRNA and protein levels in vitro and in vivo. Furthermore, knockdown of BNIP3 greatly inhibited Cd-induced cell death. Importantly, BNIP3 RNAi decreased lactate dehydrogenase release and the percentage of propidium iodide-positive cells, two markers of necrotic cell death due to rupture of the cell membrane, whereas it had no effect on activation of caspase-3 in Cd-treated cells. These data suggest that BNIP3 mediates caspase-independent necrosis, but not apoptosis. Moreover, our results indicate that induction of BNIP3 by Cd may not be related to HIF-1 which is generally regarded as a mediator responsible for BNIP3 expression. Finally, we show that mitogen-activated protein kinases (MAPKs) are activated by Cd in vitro and in vivo; ERK and JNK promote BNIP3 upregulation and subsequent necrosis. Taken together, our results suggest BNIP3, upregulated by activation of ERK and JNK, mediates Cd-induced necrosis in neuronal cells. PMID:24824807

  14. Urban air pollution produces up-regulation of myocardial inflammatory genes and dark chocolate provides cardioprotection.

    PubMed

    Villarreal-Calderon, Rodolfo; Reed, William; Palacios-Moreno, Juan; Keefe, Sheyla; Herritt, Lou; Brooks, Diane; Torres-Jardón, Ricardo; Calderón-Garcidueñas, Lilian

    2012-05-01

    Air pollution is a serious environmental problem. Elderly subjects show increased cardiac morbidity and mortality associated with air pollution exposure. Mexico City (MC) residents are chronically exposed to high concentrations of fine particulate matter (PM(2.5)) and PM-associated lipopolysaccharides (PM-LPS). To test the hypothesis that chronic exposure to urban pollution produces myocardial inflammation, female Balb-c mice age 4 weeks were exposed for 16 months to two distinctly different polluted areas within MC: southwest (SW) and northwest (NW). SW mice were given either no treatment or chocolate 2g/9.5 mg polyphenols/3 times per week. Results were compared to mice kept in clean air. Key inflammatory mediator genes: cyclooxygenase-2 (COX-2), interleukin-1? (IL-1?), interleukin-6 (IL-6), and tumor necrosis factor-? (TNF-?), and the LPS receptor CD14 (cluster of differentiation antigen 14) were measured by real-time polymerase chain reaction. Also explored were target NF?B (nuclear factor ?B), oxidative stress and antioxidant defense genes. TNF-?, IL-6, and COX-2 were significantly increased in both NW and SWMC mice (p=0.0001). CD14 was up-regulated in SW mice in keeping with the high exposures to particulate matter associated endotoxin. Chocolate administration resulted in a significant down-regulation of TNF-? (p<0.0001), IL-6 (p=0.01), and IL-1? (p=0.02). The up-regulation of antioxidant enzymes and the down-regulation of potent oxidases, toll-like receptors, and pro-apoptotic signaling genes completed the protective profile. Exposure to air pollution produces up-regulation of inflammatory myocardial genes and endotoxin plays a key role in the inflammatory response. Regular consumption of dark chocolate may reduce myocardial inflammation and have cardioprotective properties in the setting of air pollution exposures. PMID:20932730

  15. 20-hydroxyecdysone upregulates apoptotic genes and induces apoptosis in the Bombyx fat body.

    PubMed

    Tian, Ling; Liu, Shumin; Liu, Hanhan; Li, Sheng

    2012-04-01

    During insect metamorphosis, obsolete larval tissues are removed by programed cell death (PCD), mainly apoptosis and autophagy, which is directed by the molting hormone, 20-hydroxyecdysone (20E) and the 20E-triggered transcriptional cascade. Here, we investigated how 20E regulates apoptosis at the transcriptional level in the fat body of the silkworm, Bombyx mori. As detected by TdT-mediated dUTP Nick-End Labeling (TUNEL), apoptosis weakly occurred during the fourth larval molting, decreased to undetected levels during the early fifth instar, and gradually increased from day 4 of fifth instar to the wandering stage to the prepupal stage. Meanwhile, as determined by quantitative real-time PCR, eight genes involved in apoptosis, including Apaf-1, Nedd2 like1, Nedd2 like2, ICE1, ICE3, ICE5, Arp, and IAP, were highly expressed during molting and pupation, when the 20E titer is high. Injection of 20E into day 2 of fifth instar larvae significantly induced apoptosis and upregulated apoptotic genes after 6 h of treatment, and in vitro treatment of larval fat body tissues with 20E upregulated all the eight apoptotic genes. Moreover, RNAi knockdown of USP, a component of the 20E receptor complex EcR-USP, at the early-wandering stage reduced apoptosis and downregulated apoptotic genes after 24 h of treatment. Taken together, we infer that 20E upregulates apoptotic genes and thus induces apoptosis in the Bombyx fat body during larval molting and the larval-pupal transition. PMID:22517444

  16. Up-regulation of nicotinic acetylcholine receptors in menthol cigarette smokers

    PubMed Central

    Brody, Arthur L; Mukhin, Alexey G; La Charite, Jaime; Ta, Karen; Farahi, Judah; Sugar, Catherine A.; Mamoun, Michael S.; Vellios, Evan; Archie, Meena; Kozman, Maggie; Phuong, Jonathan; Arlorio, Franca; Mandelkern, Mark A.

    2013-01-01

    One-third of smokers primarily use menthol cigarettes and usage of these cigarettes leads to elevated serum nicotine levels and more difficulty quitting in standard treatment programmes. Previous brain imaging studies demonstrate that smoking (without regard to cigarette type) leads to up-regulation of ?2*-containing nicotinic acetylcholine receptors (nAChRs). We sought to determine if menthol cigarette usage results in greater nAChR up-regulation than non-menthol cigarette usage. Altogether, 114 participants (22 menthol cigarette smokers, 41 non-menthol cigarette smokers and 51 non-smokers) underwent positron emission tomography scanning using the ?4?2* nAChR radioligand 2-[18F]fluoro-A-85380 (2-FA). In comparing menthol to non-menthol cigarette smokers, an overall test of 2-FA total volume of distribution values revealed a significant between-group difference, resulting from menthol smokers having 9–28% higher ?4?2* nAChR densities than non-menthol smokers across regions. In comparing the entire group of smokers to non-smokers, an overall test revealed a significant between-group difference, resulting from smokers having higher ?4?2* nAChR levels in all regions studied (36–42%) other than thalamus (3%). Study results demonstrate that menthol smokers have greater up-regulation of nAChRs than non-menthol smokers. This difference is presumably related to higher nicotine exposure in menthol smokers, although other mechanisms for menthol influencing receptor density are possible. These results provide additional information about the severity of menthol cigarette use and may help explain why these smokers have more trouble quitting in standard treatment programmes. PMID:23171716

  17. gamma-Glutamyl transpeptidase expression in Ewing's sarcoma cells: up-regulation by interferons.

    PubMed Central

    Bouman, Lena; Sancéau, Josiane; Rouillard, Dany; Bauvois, Brigitte

    2002-01-01

    The genetic hallmark of Ewing's sarcoma family of tumours (ET) is the presence of the translocation t(11;22)(q24;q12), which creates the ET fusion gene, leading to cellular transformation. Five human gamma-glutamyl transpeptidase (gamma-GT) genes are located near the chromosomal translocation in ET. gamma-GT is a major enzyme involved in glutathione homoeostasis. Five human cell lines representative of primary or metastatic tumours were investigated to study whether gamma-GT alterations could occur at the chromosomal breaks and rearrangements in ET. As shown by enzymic assays and FACS analyses, all ET cell lines consistently expressed a functional gamma-GT which however did not discriminate steps of ET progression. As shown previously [Sancéau, Hiscott, Delattre and Wietzerbin (2000) Oncogene 19, 3372-3383], ET cells respond to the antiproliferative effects of interferons (IFNs) type I (alpha and beta) and to a much less degree to IFN type II (gamma). IFN-alpha and -beta arrested cells in the S-phase of the cell cycle. We found an enhancement of gamma-GT mRNA species with IFN-alpha and -beta by reverse transcriptase-PCR analyses. This is reflected by up-regulation of gamma-GT protein, which coincides with the increase in gamma-GT-specific enzymic activity. Similarly, IFNs up-regulate the levels of gamma-GT in another IFN-responsive B cell line. Whether this up-regulation of gamma-GT by IFNs is of physiological relevance to cell behaviour remains to be studied. PMID:12049636

  18. PTEN induces apoptosis and cavitation via HIF-2-dependent Bnip3 upregulation during epithelial lumen formation.

    PubMed

    Qi, Y; Liu, J; Saadat, S; Tian, X; Han, Y; Fong, G-H; Pandolfi, P P; Lee, L Y; Li, S

    2015-04-01

    The tumor suppressor phosphatase and tensin homolog (PTEN) dephosphorylates PIP3 and antagonizes the prosurvival PI3K-Akt pathway. Targeted deletion of PTEN in mice led to early embryonic lethality. To elucidate its role in embryonic epithelial morphogenesis and the underlying mechanisms, we used embryonic stem cell-derived embryoid body (EB), an epithelial cyst structurally similar to the periimplantation embryo. PTEN is upregulated during EB morphogenesis in parallel with apoptosis of core cells, which mediates EB cavitation. Genetic ablation of PTEN causes Akt overactivation, apoptosis resistance and cavitation blockade. However, rescue experiments using mutant PTEN and pharmacological inhibition of Akt suggest that the phosphatase activity of PTEN and Akt are not involved in apoptosis-mediated cavitation. Instead, hypoxia-induced upregulation of Bnip3, a proapoptotic BH3-only protein, mediates PTEN-dependent apoptosis and cavitation. PTEN inactivation inhibits hypoxia- and reactive oxygen species-induced Bnip3 elevation. Overexpression of Bnip3 in PTEN-null EBs rescues apoptosis of the core cells. Mechanistically, suppression of Bnip3 following PTEN loss is likely due to reduction of hypoxia-inducible factor-2? (HIF-2?) because forced expression of an oxygen-stable HIF-2? mutant rescues Bnip3 expression and apoptosis. Lastly, we show that HIF-2? is upregulated by PTEN at both transcriptional and posttranscriptional levels. Ablation of prolyl hydroxylase domain-containing protein 2 (PHD2) in normal EBs or inhibition of PHD activities in PTEN-null EBs stabilizes HIF-2? and induces Bnip3 and caspase-3 activation. Altogether, these results suggest that PTEN is required for apoptosis-mediated cavitation during epithelial morphogenesis by regulating the expression of HIF-2? and Bnip3. PMID:25394489

  19. Screening of upregulated genes induced by high density in the vetch aphid Megoura crassicauda.

    PubMed

    Ishikawa, Asano; Ishikawa, Yuki; Okada, Yasukazu; Miyazaki, Satoshi; Miyakawa, Hitoshi; Koshikawa, Shigeyuki; Brisson, Jennifer A; Miura, Toru

    2012-03-01

    Aphids exhibit several polyphenisms in which discontinuous, alternative phenotypes are produced depending on environmental conditions. One representative example is the wing polyphenism, where winged and wingless females are produced through parthenogenesis. Previous work has shown that, in some aphid species, the density condition sensed by the mother aphid determines the developmental fate of embryos in her ovary, with high densities leading to winged progeny and low densities to wingless progeny. However, little is known about the molecular and physiological mechanisms underlying the wing polyphenism. To identify genes involved in the wing-morph determination in the vetch aphid, Megoura crassicauda, we compared maternal and embryonic transcripts between high- and low-density conditions using differential display, followed by quantitative real-time PCR (qRT-PCR). Under the high-density condition, two genes (Uba1 and Naca) were found to be upregulated in maternal tissues without ovaries, while one gene (ClpP) was upregulated in ovaries containing embryos. Uba1 and Naca encode factors that function in protein modification or transcriptional/translational regulation, respectively. In addition to differential display, candidate gene approaches focusing on morphogenetic and endocrine genes, i.e., wg, dpp, ap, hh, InR, IRS, Foxo, EcR, and USP, were also carried out. We found that wg was upregulated in maternal tissues under the high-density condition. The identified genes from both approaches are candidates for further study of their involvement in the transduction of density signals in mother aphids and/or the initial process of wing differentiation in embryos. PMID:22514053

  20. Upregulation of gene expression in reward-modulatory striatal opioid systems by sleep loss.

    PubMed

    Baldo, Brian A; Hanlon, Erin C; Obermeyer, William; Bremer, Quentin; Paletz, Elliott; Benca, Ruth M

    2013-12-01

    Epidemiological studies have shown a link between sleep loss and the obesity 'epidemic,' and several observations indicate that sleep curtailment engenders positive energy balance via increased palatable-food 'snacking.' These effects suggest alterations in reward-modulatory brain systems. We explored the effects of 10 days of sleep deprivation in rats on the expression of striatal opioid peptide (OP) genes that subserve food motivation and hedonic reward, and compared effects with those seen in hypothalamic energy balance-regulatory systems. Sleep-deprived (Sleep-Dep) rats were compared with yoked forced-locomotion apparatus controls (App-Controls), food-restricted rats (Food-Restrict), and unmanipulated controls (Home-Cage). Detection of mRNA levels with in situ hybridization revealed a subregion-specific upregulation of striatal preproenkephalin and prodynorhin gene expression in the Sleep-Dep group relative to all other groups. Neuropeptide Y (NPY) gene expression in the hippocampal dentate gyrus and throughout neocortex was also robustly upregulated selectively in the Sleep-Dep group. In contrast, parallel gene expression changes were observed in the Sleep-Dep and Food-Restrict groups in hypothalamic energy-sensing systems (arcuate nucleus NPY was upregulated, and cocaine- and amphetamine-regulated transcript was downregulated), in alignment with leptin suppression in both groups. Together, these results reveal a novel set of sleep deprivation-induced transcriptional changes in reward-modulatory peptide systems, which are dissociable from the energy-balance perturbations of sleep loss or the potentially stressful effects of the forced-locomotion procedure. The recruitment of telencephalic food-reward systems may provide a feeding drive highly resistant to feedback control, which could engender obesity through the enhancement of palatable feeding. PMID:23864029

  1. Estradiol improves cardiovascular function through up-regulation of SOD2 on vascular wall

    PubMed Central

    Liu, Zhaoyu; Gou, Yulan; Zhang, Hongyu; Zuo, Houjuan; Zhang, Haimou; Liu, Zhengxiang; Yao, Dachun

    2014-01-01

    Epidemiological studies have shown that estrogens have protective effects in cardiovascular diseases, even though the results from human clinical trials remain controversial, while most of the animal experiments confirmed this effect, but the detailed mechanism remains unclear. In this study, we found that estradiol (E2) treatment significantly increases the expression of mitochondrial superoxide dismutase (SOD2) in mice and in vitro in human aorta endothelial cells. Further investigation shows that E2 up-regulates SOD2 through tethering of estrogen receptor (ER) to Sp1 and the increased binding of Sp1 to GC-box on the SOD2 promoter, where ER? responses E2-mediated gene activation, and ER? maintains basal gene expression level. The E2/ER-mediated SOD2 up-regulation results in minimized ROS generation, which highly favors healthy cardiovascular function. Gene therapy through lentivirus-carried endothelium-specific delivery to the vascular wall in high-fat diet (HFT) mice shows that the SOD2 expression in endothelial cells normalizes E2 deficiency-induced ROS generation with ameliorated mitochondrial dysfunction and vascular damage, while SOD2 knockdown worsens the problem despite the presence of E2, indicating that E2-induced SOD2 expression plays an important vasculoprotective role. To our knowledge, this is the first report for the mechanism by which E2 improves cardiovascular function through up-regulation of SOD2 in endothelial cells. In turn, this suggests a novel gene therapy through lentivirus-carried gene delivery to vascular wall for E2 deficiency-induced cardiovascular damage in postmenopausal women. PMID:25462070

  2. Upregulation of IGF-1R Expression during Neoadjuvant Therapy Predicts Poor Outcome in Breast Cancer Patients

    PubMed Central

    Heskamp, Sandra; Boerman, Otto C.; Molkenboer-Kuenen, Janneke D. M.; Wauters, Carla A.; Strobbe, Luc J. A.; Mandigers, Caroline M. P. W.; Bult, Peter; Oyen, Wim J. G.; van der Graaf, Winette T. A.; van Laarhoven, Hanneke W. M.

    2015-01-01

    Introduction The insulin-like growth factor 1 receptor (IGF-1R) may be involved in the development of resistance against conventional cancer treatment. The aim of this study was to assess whether IGF-1R expression of breast tumors changes during neoadjuvant therapy and to study whether these changes were associated with survival. Methods Paraffin embedded tumor tissue was collected from pretreatment biopsies and surgical resections of 62 breast cancer patients who were treated with neoadjuvant chemotherapy or endocrine therapy. IGF-1R expression was determined immunohistochemically and compared before and after treatment. Results High membranous IGF-1R expression at diagnosis correlated significantly with ER positivity, low tumor stage (stage I/II) and longer overall survival (p < 0.05). After neoadjuvant treatment, membranous IGF-1R expression remained the same in 41 (65%) tumors, was upregulated in 11 (18%) tumors and downregulated in 11 (18%) tumors. Changes in membranous IGF-1R expression were associated with overall survival (log-rank test: p = 0.013, multivariate cox-regression: p = 0.086). Mean overall survival time for upregulation, no change, and downregulation in IGF-1R expression was 3.0 ± 0.5 years, 7.3 ± 1.0 years and 15.0 ± 1.8 years, respectively. Changes in other parameters were not significantly associated with survival. Conclusion Neoadjuvant therapy can induce changes in IGF-1R expression. Upregulation of IGF-1R expression after neoadjuvant treatment is a poor prognostic factor in breast cancer patients, providing a rationale for incorporating anti-IGF-1R drugs in the management of these patients. PMID:25680198

  3. Zinc pyrithione impairs zinc homeostasis and upregulates stress response gene expression in reconstructed human epidermis

    PubMed Central

    Lamore, Sarah D.

    2014-01-01

    Zinc ion homeostasis plays an important role in human cutaneous biology where it is involved in epidermal differentiation and barrier function, inflammatory and antimicrobial regulation, and wound healing. Zinc-based compounds designed for topical delivery therefore represent an important class of cutaneous therapeutics. Zinc pyrithione (ZnPT) is an FDA-approved microbicidal agent used worldwide in over-the-counter topical antimicrobials, and has also been examined as an investigational therapeutic targeting psoriasis and UVB-induced epidermal hyperplasia. Recently, we have demonstrated that cultured primary human skin keratinocytes display an exquisite sensitivity to nanomolar ZnPT concentrations causing induction of heat shock response gene expression and poly(ADP-ribose) polymerase (PARP)-dependent cell death (Cell Stress Chaperones 15:309–322, 2010). Here we demonstrate that ZnPT causes rapid accumulation of intracellular zinc in primary keratinocytes as observed by quantitative fluorescence microscopy and inductively coupled plasma mass spectrometry (ICP-MS), and that PARP activation, energy crisis, and genomic impairment are all antagonized by zinc chelation. In epidermal reconstructs (EpiDerm™) exposed to topical ZnPT (0.1–2% in Vanicream™), ICP-MS demonstrated rapid zinc accumulation, and expression array analysis demonstrated upregulation of stress response genes encoding metallothionein-2A (MT2A), heat shock proteins (HSPA6, HSPA1A, HSPB5, HSPA1L, DNAJA1, HSPH1, HSPD1, HSPE1), antioxidants (SOD2, GSTM3, HMOX1), and the cell cycle inhibitor p21 (CDKN1A). IHC analysis of ZnPT-treated EpiDerm™ confirmed upregulation of Hsp70 and TUNEL-positivity. Taken together our data demonstrate that ZnPT impairs zinc ion homeostasis and upregulates stress response gene expression in primary keratinocytes and reconstructed human epidermis, activities that may underlie therapeutic and toxicological effects of this topical drug. PMID:21424779

  4. Up-regulation of mitochondrial chaperone TRAP1 in ulcerative colitis associated colorectal cancer

    PubMed Central

    Chen, Ru; Pan, Sheng; Lai, Keith; Lai, Lisa A; Crispin, David A; Bronner, Mary P; Brentnall, Teresa A

    2014-01-01

    AIM: To characterize tumor necrosis factor receptor-associated protein 1 (TRAP1) expression in the progression of ulcerative colitis (UC)-associated colorectal cancer. METHODS: Chronic UC is an inflammatory bowel disease that predisposes to colorectal cancer. Immunohistochemical analysis was used to evaluate TRAP1 expression on tissue microarrays containing colonic tissues from 42 UC progressors (patients with cancer or dysplasia) and 38 non-progressors (dysplasia/cancer free patients). Statistical analyses of the TRAP1 immunohistochemistry staining were performed using GraphPad Prism. Differences in the TRAP1 level between non-progressors and progressors were tested for statistical significance using the Mann-Whitney test. Receiver operating characteristic curve method was used to quantify marker performance in distinguishing diseased cases from controls. RESULTS: TRAP1 was up-regulated in the colon tissues from UC progressors, but not in the colon tissues from UC non-progressors. Moreover, up-regulation of TRAP1 preceded the neoplastic changes: it was present in both the dysplastic and non-dysplastic tissues of UC progressors. When TRAP1 staining in rectal tissue was used as a diagnostic marker, it could distinguish progressors from non-progressors with 59% sensitivity and 80% specificity. Our study further showed that the increase of TRAP1 expression positively correlated with the degree of inflammation in the colorectal cancer tissues, which could be related to the increased oxidation present in the colonic mucosa from UC progressors. We then investigated the cellular proteome changes underlying oxidative stress, and found that oxidative stress could induce up-regulation of TRAP1 along with several other negative modulators of apoptosis. CONCLUSION: These results suggest that oxidative stress in long standing UC could lead to the increase of cytoprotective protein TRAP1, which in turn could promote cancer progression by preventing or protecting the oxidative damaged epithelial cells from undergoing apoptosis. TRAP1 could be a potential diagnostic marker for UC associated colorectal cancer. PMID:25493016

  5. MicroRNA-99a and 100 mediated upregulation of FOXA1 in bladder cancer.

    PubMed

    Drayton, Ross M; Peter, Stefan; Myers, Katie; Miah, Saiful; Dudziec, Ewa; Bryant, Helen E; Catto, James W F

    2014-08-15

    Urothelial cell carcinoma of the bladder (UCC) is a common disease often characterized by FGFR3 dysregulation. Whilst upregulation of this oncogene occurs most frequently in low-grade non-invasive tumors, recent data reveal increased FGFR3 expression characterizes a common sub-type of invasive UCC sharing molecular similarities with breast cancer. These similarities include upregulation of the FOXA1 transcription factor and reduced expression of microRNAs-99a/100. We have previously identified direct regulation of FGFR3 by these two microRNAs and now search for further targets. Using a microarray meta-database we find potential FOXA1 regulation by microRNAs-99a/100. We confirm direct targeting of the FOXA1 3'UTR by microRNAs-99a/100 and also potential indirect regulation through microRNA-485-5p/SOX5/JUN-D/FOXL1 and microRNA-486/FOXO1a. In 292 benign and malignant urothelial samples, we find an inverse correlation between the expression of FOXA1 and microRNAs-99a/100 (r=-0.33 to -0.43, p<0.05). As for FGFR3 in UCC, tumors with high FOXA1 expression have lower rates of progression than those with low expression (Log rank p=0.009). Using global gene expression and CpG methylation profiling we find genotypic consequences of FOXA1 upregulation in UCC. Genetic changes are associated with regional hypomethylation, occur near FOXA1 binding sites, and mirror gene expression changes previously reported in FGFR3 mutant-UCC. These include gene silencing through aberrant hypermethylation (e.g. IGFBP3) and affect genes characterizing breast cancer sub-types (e.g. ERBB2). In conclusion, we have identified microRNAs-99a/100 mediate a direct relationship between FGFR3 and FOXA1 and potentially facilitate cross talk between these pathways in UCC. PMID:25071007

  6. The Natural Antimicrobial Enzyme Lysozyme is Up-Regulated in Gastrointestinal Inflammatory Conditions

    PubMed Central

    Rubio, Carlos A.

    2014-01-01

    The cells that line the mucosa of the human gastrointestinal tract (GI, that is, oral cavity, oesophagus, stomach, small intestine, large intestine, and rectum) are constantly challenged by adverse micro-environmental factors, such as different pH, enzymes, and bacterial flora. With exception of the oral cavity, these microenvironments also contain remnant cocktails of secreted enzymes and bacteria from upper organs along the tract. The density of the GI bacteria varies, from 103/mL near the gastric outlet, to 1010/mL at the ileocecal valve, to 1011 to 1012/mL in the colon. The total microbial population (ca. 1014) exceeds the total number of cells in the tract. It is, therefore, remarkable that despite the prima facie inauspicious mixture of harmful secretions and bacteria, the normal GI mucosa retains a healthy state of cell renewal. To counteract the hostile microenvironment, the GI epithelia react by speeding cell exfoliation (the GI mucosa has a turnover time of two to three days), by increasing peristalsis, by eliminating bacteria through secretion of plasma cell-immunoglobulins and by increasing production of natural antibacterial compounds, such as defensin-5 and lysozyme. Only recently, lysozyme was found up-regulated in Barrett’s oesophagitis, chronic gastritis, gluten-induced atrophic duodenitis (coeliac disease), collagenous colitis, lymphocytic colitis, and Crohn’s colitis. This up-regulation is a response directed to the special types of bacteria recently detected in these diseases. The aim of lysozyme up-regulation is to protect individual mucosal segments to chronic inflammation. The molecular mechanisms connected to the crosstalk between the intraluminal bacterial flora and the production of lysozyme released by the GI mucosae, are discussed. Bacterial resistance continues to exhaust our supply of commercial antibiotics. The potential use of lysozyme to treat infectious diseases is receiving much attention. PMID:25437608

  7. KSHV encoded LANA upregulates Pim-1 and is a substrate for its kinase activity

    SciTech Connect

    Bajaj, Bharat G. [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States); Verma, Subhash C. [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States); Lan, Ke [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States); Cotter, Murray A. [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States); Woodman, Zenda L. [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States); Robertson, Erle S. [Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, University of Pennsylvania Medical School, 201E Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104 (United States)]. E-mail: erle@mail.med.upenn.edu

    2006-07-20

    Pim kinases are proto-oncogenes that are upregulated in a number of B cell cancers, including Epstein-Barr Virus (EBV) associated Burkitt's lymphoma. They have also been shown to be upregulated in Kaposi sarcoma-associated herpes virus (KSHV) infected primary B cells. Most cells in KSHV-associated tumors are latently infected and express only a small subset of viral genes, with KSHV latency associated nuclear antigen (LANA) being constitutively expressed. LANA regulates the transcription of a large number of cellular and viral genes. Here, we show that LANA upregulates transcription from the Pim-1 promoter (pPim-1) and map this activation to a region in the promoter located within the sequence (-681 to +37). We show that LANA expressing cells can proliferate faster and are better protected from drug induced apoptosis. Since transition through cell cycle check points and anti-apoptosis are functions associated with Pim-1, it is likely that higher Pim-1 expression in cells expressing LANA is responsible, at least in part, for this effect. A Pim-1 phosphorylation site was also identified within the amino-terminal domain of LANA. Using in vitro kinase assays, we confirmed that LANA was indeed a Pim-1 substrate, and the failure of Pim-1 to phosphorylate LANA mutated at SS205/6RR identified this site as the specific serine residues phosphorylated by Pim-1. This report provides valuable insight into yet another cellular signaling pathway subverted by KSHV LANA and suggests a contribution to KSHV related oncogenesis.

  8. Erbb2 up-regulation of ADAM12 expression accelerates skin cancer progression.

    PubMed

    Rao, Velidi H; Vogel, Kristen; Yanagida, Jodi K; Marwaha, Nitin; Kandel, Amrit; Trempus, Carol; Repertinger, Susan K; Hansen, Laura A

    2014-05-01

    Solar ultraviolet (UV) radiation can cause severe damage to the skin and is the primary cause of most skin cancer. UV radiation causes DNA damage leading to mutations and also activates the Erbb2/HER2 receptor through indirect mechanisms involving reactive oxygen species. We hypothesized that Erbb2 activation accelerates the malignant progression of UV-induced skin cancer. Following the induction of benign squamous papillomas by UV exposure of v-ras(Ha) transgenic Tg.AC mice, mice were treated topically with the Erbb2 inhibitor AG825 and tumor progression monitored. AG825 treatment reduced tumor volume, increased tumor regression, and delayed the development of malignant squamous cell carcinoma (SCC). Progression to malignancy was associated with increased Erbb2 and ADAM12 (A Disintegin And Metalloproteinase 12) transcripts and protein, while inhibition of Erbb2 blocked the increase in ADAM12 message upon malignant progression. Similarly, human SCC and SCC cell lines had increased ADAM12 protein and transcripts when compared to normal controls. To determine whether Erbb2 up-regulation of ADAM12 contributed to malignant progression of skin cancer, Erbb2 expression was modulated in cultured SCC cells using forced over-expression or siRNA targeting, demonstrating up-regulation of ADAM12 by Erbb2. Furthermore, ADAM12 transfection or siRNA targeting revealed that ADAM12 increased both the migration and invasion of cutaneous SCC cells. Collectively, these results suggest Erbb2 up-regulation of ADAM12 as a novel mechanism contributing to the malignant progression of UV-induced skin cancer. Inhibition of Erbb2/HER2 reduced tumor burden, increased tumor regression, and delayed the progression of benign skin tumors to malignant SCC in UV-exposed mice. Inhibition of Erbb2 suppressed the increase in metalloproteinase ADAM12 expression in skin tumors, which in turn increased migration and tumor cell invasiveness. © 2014 Wiley Periodicals, Inc. PMID:24798404

  9. HDG11 upregulates cell-wall-loosening protein genes to promote root elongation in Arabidopsis

    PubMed Central

    Xu, Ping; Cai, Xiao-Teng; Wang, Yao; Xing, Lu; Chen, Qiong; Xiang, Cheng-Bin

    2014-01-01

    The gain-of-function mutant edt1 shows significantly enhanced drought tolerance and a well-developed root system including deeper primary roots and more lateral roots. To explore the molecular mechanisms underlying the improved root system of edt1, we performed transcriptome comparison between the wild-type and edt1 roots. One of the interesting findings from the analysis was that several gene families of cell-wall-loosening proteins were upregulated in the mutant roots, including expansins, extensins, xyloglucan endotransglucosylase/hydrolases (XTHs), pectin-related enzymes, and cellulases. Most of these genes contain HD-binding cis-elements in their promoters predominantly with the TTTAATTT sequence, which can be bound by HDG11 in vitro and in vivo. The coordinated expression of these gene families overlaps fast root elongation. Furthermore, overexpression of AtEXPA5, which was dramatically upregulated in edt1, resulted in longer primary roots because cells were more extended longitudinally. When combined by crossing the AtEXPA5-overexpression lines with one pectin methylesterase inhibitor family protein (PMEI) gene (At5g62360)- or one cellulase (CEL) gene (At2g32990)-overexpression lines, the primary roots of the progeny even exceeded both parents in length. Our results demonstrate that HDG11 directly upregulates cell-wall-loosening protein genes, which is correlated with altered root system architecture, and confirm that cell-wall-loosening proteins play important roles in coordinating cell-wall extensibility with root development. The results of transgene experiments showed that expansin works together with PMEI and CEL to generate synergistic effects on primary root elongation, suggesting that different cell-wall-loosening protein families may function in combination to generate optimal effects on root extensibility. PMID:24821957

  10. TGF? mediated upregulation of hepatic miR-181b promotes hepatocarcinogenesis by targeting TIMP3

    PubMed Central

    Wang, Bo; Hsu, Shu-Hao; Majumder, Sarmila; Kutay, Huban; Huang, Wei; Jacob, Samson T.; Ghoshal, Kalpana

    2009-01-01

    To identify microRNAs that may play a causal role in hepatocarcinogenesis, we used an animal model in which C57/BL6 mice fed choline deficient and amino acid defined (CDAA) diet develop preneoplastic lesions at 65 weeks and hepatocellular carcinomas after 84 weeks. miRNA expression profiling showed significant upregulation of miR-181b and miR-181d in the livers of mice as early as 32 weeks that persisted at preneoplastic stage. The expression of TIMP3, a tumor suppressor and a validated miR-181 target, was markedly suppressed in the livers of mice fed CDAA diet. Upregulation of hepatic TGF? and its downstream mediators Smad 2, 3 and 4 and increase in phospho-Smad2 in the liver nuclear extract correlated with elevated miR-181b/d in mice fed CDAA diet. The levels of the precursor and mature miR-181b were augmented upon exposure of hepatic cells to TGF? and were significantly reduced by siRNA-mediated depletion of Smad4, demonstrating the involvement of TGF? signaling pathway in miR-181b expression. Ectopic expression and depletion of miR-181b showed that miR-181b enhanced MMP2 and MMP9 activity and promoted growth, clonogenic survival, migration and invasion of HCC cells that could be reversed by modulating TIMP3 level. Further, depletion of miR-181b inhibited tumor growth of HCC cells in nude mice. miR-181b also enhanced resistance of HCC cells to the anti-cancer drug doxorubicin. Based on these results, we conclude that upregulation of miR-181b at early stages of feeding CDAA diet promotes hepatocarcinogenesis. PMID:20023698

  11. p38? MAPK upregulates atrogin1/MAFbx by specific phosphorylation of C/EBP?

    PubMed Central

    2012-01-01

    Background The p38 mitogen-activated protein kinases (MAPK) family plays pivotal roles in skeletal muscle metabolism. Recent evidence revealed that p38? and p38? exert paradoxical effects on muscle protein homeostasis. However, it is unknown why p38?, but not p38?, is capable of mediating muscle catabolism via selective activation of the C/EBP? that upregulates atrogin1/MAFbx. Methods Tryptic phosphopeptide mapping was carried out to identify p38?- and p38?-mediated phosphorylation sites in C/EBP?. Chromosome immunoprecipitation (ChIP) assay was used to evaluate p38? and p38? effect on C/EBP? binding to the atrogin1/MAFbx promoter. Overexpression or siRNA-mediated gene knockdown of p38? and p38?, and site-directed mutagenesis or knockout of C/EBP?, were used to analyze the roles of these kinases in muscle catabolism in C2C12 myotubes and mice. Results Cellular expression of constitutively active p38? or p38? resulted in phosphorylation of C/EBP? at multiple serine and threonine residues; however, only p38? phosphorylated Thr-188, which had been known to be critical to the DNA-binding activity of C/EBP?. Only p38?, but not p38?, activated C/EBP?-binding to the atrogin1/MAFbx promoter. A C/EBP? mutant in which Thr-188 was replaced by alanine acted as a dominant-negative inhibitor of atrogin1/MAFbx upregulation induced by either p38? or Lewis lung carcinoma (LLC) cell-conditioned medium (LCM). In addition, knockdown of p38? specifically inhibited C/EBP? activation and atrogin1/MAFbx upregulation induced by LCM. Finally, expression of active p38? in mouse tibialis anterior specifically induced C/EBP? phosphorylation at Thr-188, atrogin1/MAFbx upregulation and muscle mass loss, which were blocked in C/EBP?-null mice. Conclusions The ? and ? isoforms of p38 MAPK are capable of recognizing distinct phosphorylation sites in a substrate. The unique capacity of p38? in mediating muscle catabolism is due to its capability in phosphorylating Thr-188 of C/EBP?. PMID:23046544

  12. Pharmacological upregulation of PGC1? in oligodendrocytes: implications for Huntington's Disease.

    PubMed

    Xiang, Zhongmin; Krainc, Dimitri

    2013-01-01

    The coactivator PGC1? plays a role in the transcriptional regulation of energy metabolism and its deficiency has been implicated in abnormalities of myelination and oligodendrocyte differentiation in Huntington's disease (HD). In an effort to activate PGC1? in oligodendrocytes, we found that overexpression of SIRT1 or treatment with resveratrol (RSV) and SRT1720 upregulated PGC1? expression and increased oligodendrocyte differentiation. Interestingly, in oligodendrocytes expressing mutant huntingtin, SRT1720 but not RSV was able to restore PGC1? expression and the differentiation. These results suggest that pharmacological activation of PGC1? in oligodendrocytes by SRT1720 may provide a therapeutic opportunity for correction of deficient myelination in HD. PMID:25063433

  13. EGF Up-Regulates miR-31 through the C/EBP? Signal Cascade in Oral Carcinoma

    PubMed Central

    Yang, Cheng-Chieh; Tu, Hsi-Feng; Wu, Cheng-Hsien; Chang, Kuo-Wei; Lin, Shu-Chun

    2014-01-01

    Oral squamous cell carcinoma (OSCC) is one of the most prevalent carcinomas worldwide. MicroRNAs (miRNAs) are short, non-coding RNAs that regulate gene expression and modulate physiological or pathological processes including OSCC carcinogenesis. miR-31 has been found to be up-regulated in OSCC and to act as an oncogenic miRNA. However, the molecular mechanism underlying miR-31 up-regulation in OSCC is still obscure. The activation of epidermal growth factor receptor (EGFR) signaling axis plays key roles in driving oral carcinogenesis. Our screening identified that there is up-regulation of miR-31, miR-181b and miR-222 in OSCC cells following EGF treatment. Subsequent analysis showed that EGF treatment led to AKT activation, which then resulted in miR-31 up-regulation. Moreover, EGF treatment and the AKT activation induced by exogenous expression up-regulated C/EBP? expression. The miR-31 up-regulation induced by EGF was abrogated by AKT inhibition or by the knockdown of C/EBP? expression. In OSCC cell subclones stably overexpressing the functional isoform of C/EBP?, miR-31 expression was up-regulated. Curcumin is a natural ingredient exhibiting anti-cancer potential. It was found that curcumin attenuated AKT activation and the up-regulation of C/EBP? and miR-31 caused by EGF stimulation in OSCC cells. Lastly, concordance across the expression of EGFR, the expression of C/EBP? and the expression of miR-31 in OSCC tissues was found. This study describes a novel scenario where the up-regulation of miR-31 expression in OSCC is, at least in part, a consequence of EGFR oncogenic activation. Although the AKT activation and C/EBP? expression after EGF treatment might not be directly linked, both events are the crucial mediators underlying miR-31 up-regulation in the EGFR signaling axis. PMID:25229239

  14. Aluminum effect on lipid peroxidation and on the activities of superoxide dismutase and catalase in the cerebral hemisphere and liver of young chicks.

    PubMed

    Swain, C; Chainy, G B

    1997-06-01

    Aluminum was injected (i.p.) as aluminum sulphate (4, 40 and 100 mg/kg body weight, n = 5 per group) daily into day-old White Leghorn male chicks for 7, 15 and 30 days. Aluminum (Al) treatment (100 mg dose) to chicks over 7 and 30 days resulted in a decrease in activities of cytosolic total and CN(-)-sensitive superoxide dismutase (SOD) in the cerebral hemisphere (CH). In the 15-day treated group, activities of cytosolic total, CN(-)-sensitive and CN(-)-insensitive SOD of CH were decreased in response to all doses of Al. In the liver, activities of cytosolic total and CN(-)-sensitive SOD were decreased in response to all doses of Al treatment for 7 and 15 days. But 40 and 100 mg doses were effective in decreasing activities of the enzymes in the 30-day treated group. The catalase (CAT) activity of CH of chicks was inhibited by all doses of Al under treatment for 7 days, but was inhibited only in the case of the 100 mg dose when the duration of treatment was increased to 15 days. The inhibition was again observed in chicks treated for 30 days in response to 40 and 100 mg doses. CAT activity of liver of chicks was decreased in response to all doses of Al in the 7-day treated group and in response to 40 and 100 mg doses in the 15- and 30-day treated groups. Al treatment did not affect lipid peroxide levels of CH and liver of chicks. These results suggest that decrease in activities in SOD and CAT in CH and liver of the chicks after Al treatment constitutes one of the factors for the mechanism of tissue injury by Al. PMID:9285887

  15. Amplified amperometric aptasensor for selective detection of protein using catalase-functional DNA-PtNPs dendrimer as a synergetic signal amplification label.

    PubMed

    Zhang, Juan; Yuan, Yali; biXie, Shun; Chai, Yaqin; Yuan, Ruo

    2014-10-15

    In this work, we present a new strategy to construct an electrochemical aptasensor for sensitive detection of platelet-derived growth factor BB (PDGF-BB) based on the synergetic amplification of a three-dimensional (3D) nanoscale catalase (CAT) enzyme-functional DNA-platinum nanoparticles (PtNPs) dendrimer through autonomous layer-by-layer assembly. Firstly, polyamidoaminedendrimer (PAMAM) with a hyper-branched and three-dimensional structure was served as nanocarriers to coimmobilize a large number of PDGF-BB binding aptamer (PBA II) and ssDNA 1 (S1) to form PBA II-PAMAM-S1 bioconjugate. In the presence of PDGF-BB, the bioconjugate was self-assembled on the electrode by sandwich assay. Following that, the carried S1 propagated a chain reaction of hybridization events between CAT-PtNPs-S1 and CAT-PtNPs-ssDNA 2 (S2) to form a 3D nanoscale CAT-functional PtNPs-DNA dendrimer, which successfully immobilized substantial CAT enzyme and PtNPs with superior catalysis activity. In this process, the formed negatively charged double-helix DNA could cause the intercalation of hexaammineruthenium(III) chloride (RuHex) into the groove via electrostatic interactions. Thus, numerous RuHex redox probes and CAT were decorated inside/outside of the dendrimer. In the presence of H2O2 in electrolytic cell, the synergistic reaction of CAT and PtNPs towards electrocatalysis could further amplify electrochemical signal. Under optimal condition, the CAT-PtNPs-DNA dendrimer-based sensing system presented a linear dependence between the reduction peak currents and logarithm of PDGF-BB concentrations in the range of 0.00005-35 nM with a relatively low detection limit of 0.02 pM. PMID:24813911

  16. Enhanced Reactive Oxygen Species Scavenging by Overproduction of Superoxide Dismutase and Catalase Delays Postharvest Physiological Deterioration of Cassava Storage Roots1[C][W][OA

    PubMed Central

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

    2013-01-01

    Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava. PMID:23344905

  17. Redox regulation of antioxidant enzymes: post-translational modulation of catalase and glutathione peroxidase activity by resveratrol in diabetic rat liver.

    PubMed

    Sadi, Gökhan; Bozan, Davut; Yildiz, Huseyin Bekir

    2014-08-01

    Resveratrol is a strong antioxidant that exhibits blood glucose-lowering effects, which might contribute to its usefulness in preventing complications associated with diabetes. The present study aimed to investigate resveratrol effects on catalase (CAT) and glutathione peroxidase (GPx) gene and protein expression, their phosphorylation states and activities in rat liver of STZ-induced diabetes. Diabetes increased the levels of total protein phosphorylation and p-CAT, while mRNA expression, protein levels, and activity were reduced. Although diabetes induced transcriptional repression over GPx, it did not affect the protein levels and activity. When resveratrol was administered to diabetic rats, an increase in activity was associated with an increase in p-GPx levels. Decrease in Sirtuin1 (SIRT1) and nuclear factor erythroid 2-related factor (Nrf2) and increase in nuclear factor kappa B (NF?B) gene expression in diabetes were associated with a decrease in CAT and GPx mRNA expression. A possible compensatory mechanism for reduced gene expression of antioxidant enzymes is proved to be nuclear translocation of redox-sensitive Nrf2 and NF?B in diabetes which is confirmed by the increase in nuclear and decrease in cytoplasmic protein levels of Nrf2 and NF?B. Taken together, these findings revealed that an increase in the oxidized state in diabetes intricately modified the cellular phosphorylation status and regulation of antioxidant enzymes. Gene regulation of antioxidant enzymes was accompanied by nuclear translocation of Nrf2 and NF?B. Resveratrol administration also activated a coordinated cytoprotective response against diabetes-induced changes in liver tissues. PMID:24740756

  18. Brain catalase in the streptozotocin-rat model of sporadic Alzheimer's disease treated with the iron chelator-monoamine oxidase inhibitor, M30.

    PubMed

    Sofic, E; Salkovic-Petrisic, M; Tahirovic, I; Sapcanin, A; Mandel, S; Youdim, M; Riederer, P

    2015-04-01

    Low intracerebroventricular (icv) doses of streptozotocin (STZ) produce regionally specific brain neurochemical changes in rats that are similar to those found in the brain of patients with sporadic Alzheimer's disease (sAD). Since oxidative stress is thought to be one of the major pathologic processes in sAD, catalase (CAT) activity was estimated in the regional brain tissue of animals treated intracerebroventricularly with STZ and the multitarget iron chelator, antioxidant and MAO-inhibitor M30 [5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline]. Five-day oral pre-treatment of adult male Wistar rats with 10 mg/kg/day M30 dose was followed by a single injection of STZ (1 mg/kg, icv). CAT activity was measured colorimetrically in the hippocampus (HPC), brain stem (BS) and cerebellum (CB) of the control, STZ-, M30- and STZ + M30-treated rats, respectively, 4 weeks after the STZ treatment. STZ-treated rats demonstrated significantly lower CAT activity in all three brain regions in comparison to the controls (p < 0.05 for BS and CB, p < 0.01 for HPC). M30 pre-treatment of the control rats did not influence the CAT activity in HPC and CB, but significantly increased it in BS (p < 0.05). M30 pre-treatment of STZ-treated rats significantly increased CAT activity in the HPC in comparison to the STZ treatment alone (p < 0.05) and normalized to the control values. These findings are in line with the assumption that reactive oxygen species contribute to the pathogenesis of STZ in a rat model of sAD and indicate that multifunctional iron chelators such as M30 might also have beneficial effects in this non-transgenic sAD model. PMID:25252744

  19. Superoxide dismutase, catalase, glutathione peroxidase and gluthatione S-transferases M1 and T1 gene polymorphisms in three Brazilian population groups

    PubMed Central

    de Oliveira Hiragi, Cássia; Miranda-Vilela, Ana Luisa; Rocha, Dulce Maria Sucena; de Oliveira, Silviene Fabiana; Hatagima, Ana; de Nazaré Klautau-Guimarães, Maria

    2011-01-01

    Antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX1) reduce the oxidation rates in the organism. Gluthatione S-transferases (GSTs) play a vital role in phase 2 of biotransformation of many substances. Variation in the expression of these enzymes suggests individual differences for the degree of antioxidant protection and geographical differences in the distribution of these variants. We described the distribution frequency of CAT (21A/T), SOD2 (Ala9Val), GPX1 (Pro198Leu), GSTM1 and GSTT1 polymorphisms in three Brazilian population groups: Kayabi Amerindians (n = 60), Kalunga Afro-descendants (n = 72), and an urban mixed population from Federal District (n = 162). Frequencies of the variants observed in Kalunga (18% to 58%) and Federal District (33% to 63%) were similar to those observed in Euro and Afro-descendants, while in Kayabi (3% to 68%), depending on the marker, frequencies were similar to the ones found in different ethnic groups. Except for SOD2 in all population groups studied here, and for GPX1 in Kalunga, the genotypic distributions were in accordance with Hardy-Weinberg Equilibrium. These data can clarify the contribution of different ethnicities in the formation of mixed populations, such as that of Brazil. Moreover, outcomes will be valuable resources for future functional studies and for genetic studies in specific populations. If these studies are designed to comprehensively explore the role of these genetic polymorphisms in the etiology of human diseases they may help to prevent inconsistent genotype-phenotype associations in pharmacogenetic studies. PMID:21637536

  20. Pepino mosaic virus triple gene block protein 1 (TGBp1) interacts with and increases tomato catalase 1 activity to enhance virus accumulation.

    PubMed

    Mathioudakis, Matthaios M; Veiga, Rita S L; Canto, Tomas; Medina, Vicente; Mossialos, Dimitris; Makris, Antonios M; Livieratos, Ioannis

    2013-08-01

    Various plant factors are co-opted by virus elements (RNA, proteins) and have been shown to act in pathways affecting virus accumulation and plant defence. Here, an interaction between Pepino mosaic virus (PepMV) triple gene block protein 1 (TGBp1; p26) and tomato catalase 1 (CAT1), a crucial enzyme in the decomposition of toxic hydrogen peroxide (H?O?), was identified using the yeast two-hybrid assay, and confirmed via an in?vitro pull-down assay and bimolecular fluorescent complementation (BiFC) in?planta. Each protein was independently localized within loci in the cytoplasm and nuclei, sites at which their interaction had been visualized by BiFC. Following PepMV inoculation, CAT mRNA and protein levels in leaves were unaltered at 0, 3 and 6 days (locally) and 8 days (systemically) post-inoculation; however, leaf extracts from the last two time points contained increased CAT activity and lower H?O? evels. Overexpression of PepMV p26 in?vitro and in?planta conferred the same effect, suggesting an additional involvement of TGBp1 in potexvirus pathogenesis. The accumulation of PepMV genomic and subgenomic RNAs and the expression of viral coat protein in noninoculated (systemic) leaves were reduced significantly in CAT-silenced plants. It is postulated that, during PepMV infection, a p26-CAT1 interaction increases H?O? cavenging, thus acting as a negative regulator of plant defence mechanisms to promote PepMV infections. PMID:23634807