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Sample records for catalase overexpression reduces

  1. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

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    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  2. Catalase from the silkworm, Bombyx mori: gene sequence, distribution, and overexpression.

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    Yamamoto, Kohji; Banno, Yutaka; Fujii, Hiroshi; Miake, Fumio; Kashige, Nobuhiro; Aso, Yoichi

    2005-04-01

    Living organisms require mechanisms regulating reactive oxygen species (ROS) such as hydrogen peroxide and superoxide anion. Catalase is one of the regulatory enzymes and facilitates the degradation of hydrogen peroxide to oxygen and water. Biochemical information on an insect catalase is, however, insufficient. Using mRNA from fat body of the silkworm, Bombyx mori, a cDNA encoding a putative catalase was amplified by reverse transcriptase-polymerase chain reaction and sequenced. The deduced amino acid sequence comprised 507 residues with more than seventy residues forming a scaffold for a heme cofactor conserved. The sequence showed 71% and 66% identities to those of the Drosophila melanogaster and Apis mellifera catalases, respectively; the catalase from B. mori was estimated to be phylogenetically close to that from A. mellifera. The transcripts of the gene and the catalase activity were distributed in diverse tissues of B. mori, suggesting its ubiquitous nature. Using the gene, a recombinant catalase (rCAT) was functionally overexpressed in a soluble form using Escherichia coli, purified to homogeneity, and characterized. The pH-optimum of rCAT was broad around pH 8.0. More than 80% of the original rCAT activity was retained after incubation in the following conditions: at pH 8-11 and 4 degrees C for 24 h; at pH 7 and temperatures below 50 degrees C for 30 min. The Michaelis constant for hydrogen peroxide was evaluated to be 28 mM at pH 6.5 and 30 degrees C. rCAT was suggested to be a member of the typical catalase family. PMID:15763464

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

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    Kandadi Machender R

    2012-11-01

    Full Text Available Abstract 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 μg/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.

  4. Over-expression of DAAO and catalase in Kluyveromyces marxianus through media optimization, permeabilization and GA stabilization techniques.

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    Kostova, Donka D; Petrova, Ventsislava Y; Kujumdzieva, Anna V

    2008-01-01

    The selected thermotolerant, lactose-utilizing yeast strain Kluyveromyces marxianus NBIMCC 8362 possesses high specific d-amino acid oxidase activity (60Ug(-1)), which was increased nine-fold (545Ug(-1)) by design of the growth medium and conditions for d-amino oxidase induction. Applying an optimized simple and rapid procedure for chemical permeabilization of K. marxianus cells with the cationic detergent cetyltrimethylammonium bromide, the enzyme activities (d-amino acid oxidase and catalase) of the cells have been further increased for up to 43- and 58-fold, respectively. However, the enzyme activities of the permeabilized cells decreased rapidly due to the leakage of the enzymes. Treating the permeabilized cells with 0.1% glutaraldehyde at 4°C for 10min stabilized the enzyme in the cells and prevented their outflow. The process is stable for 10 cycles and the productivity measured was 16.6mmmoll(-1)h(-1). The d-alanine transformation efficiency of K. marxianus permeabilized and GA entrapted cells was 98%. PMID:22578860

  5. Catalase improves saccharification of lignocellulose by reducing lytic polysaccharide monooxygenase-associated enzyme inactivation

    OpenAIRE

    Scott, Brian R.; Huang, Hong Zhi; Frickman, Jesper; Halvorsen, Rune; Johansen, Katja S.

    2015-01-01

    Objectives Efficient enzymatic saccharification of plant cell wall material is key to industrial processing of agricultural and forestry waste such as straw and wood chips into fuels and chemicals. Results Saccharification assays were performed on steam-pretreated wheat straw under ambient and O2-deprived environments and in the absence and presence of a lytic polysaccharide monooxygenase (LPMO) and catalase. A kinetic model was used to calculate catalytic rate and first-order inactivation ra...

  6. Tratamento pós-menopausa reduz a atividade da catalase e atenua o risco cardiovascular Postmenopausal therapy reduces catalase activity and attenuates cardiovascular risk

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    Vera S. Castanho

    2012-11-01

    Full Text Available FUNDAMENTO: A menopausa pode levar a alterações na saúde feminina, com mudanças no estado oxidativo de mulheres pós-menopausadas, para as quais são limitadas as informações relativas à influência da hormonioterapia (HT sobre as atividades das enzimas antioxidantes. OBJETIVO: Avaliar a influência da HT sobre a atividade da catalase, concentrações de lipídeos e lipoproteínas, proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, nitratos, proteína C-reativa ultrassensível e espessura da carótida em mulheres pós-menopausadas. MÉTODOS: Foram alocadas 94 mulheres para um de quatro grupos com ou sem HT. O último grupo foi subdividido em mulheres sendo tratadas com estrógeno e outras com estrógeno mais progestágeno. Foram realizadas medidas de parâmetros bioquímicos plasmáticos e da espessura da íntima-média da carótida. RESULTADOS: A HT antagonizou a redução na atividade da catalase após a menopausa, mas não teve efeito sobre os níveis da proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, peróxido lipídico, nitrato e proteína C reativa ultrassensível, nem sobre a espessura da íntima-média da carótida. A análise multivariada mostrou que a HT baseada em estrógeno atenuou a relação entre os fatores de risco cardiovasculares e a espessura da íntima-média da carótida comum. CONCLUSÃO: Este estudo mostra que a HT em mulheres pós-menopausadas produz efeitos antioxidantes e antiateroscleróticos benéficos por melhorar as concentrações séricas de lipídios e lipoproteínas, aumentar a atividade da catalase sérica e atenuar a associação entre os fatores de risco cardiovasculares e a aterosclerose precoce.BACKGROUND: Menopause can lead to alterations in women's health, with changes in the oxidative status of postmenopausal women in whom information regarding the influence of hormone therapy (HT on antioxidant

  7. Oversynthesis of riboflavin in the yeast Pichia guilliermondii is accompanied by reduced catalase and superoxide dismutases activities.

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    Prokopiv, Tetyana M; Fedorovych, Dariya V; Boretsky, Yuriy R; Sibirny, Andriy A

    2013-01-01

    Iron deficiency causes oversynthesis of riboflavin in several yeast species, known as flavinogenic yeasts. Under iron deprivation conditions, Pichia guilliermondii cells increase production of riboflavin and malondialdehyde and the formation of protein carbonyl groups, which reflect increased intracellular content of reactive oxygen species. In this study, we found that P. guilliermondii iron deprived cells showed dramatically decreased catalase and superoxide dismutase activities. Previously reported mutations rib80, rib81, and hit1, which affect repression of riboflavin synthesis and iron accumulation by iron ions, caused similar drops in activities of the mentioned enzymes. These findings could explain the previously described development of oxidative stress in iron deprived or mutated P. guilliermondii cells that overproduce riboflavin. Similar decrease in superoxide dismutase activities was observed in iron deprived cells in the non-flavinogenic yeast Saccharomyces cerevisiae. PMID:23053489

  8. Effect on post-cryopreserved semen characteristics of Holstein bulls of adding combinations of vitamin C and either catalase or reduced glutathione to Tris extender.

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    Eidan, Sajeda M

    2016-04-01

    This study was undertaken to investigate the influence of adding combinations of vitamin C to Tris extender with either catalase or reduced glutathione on post-cryopreserved semen characteristics of Holstein bulls for different preservation periods (cooling at 5°C, 48 h, 1, 2 and 3 months post cryopreservation, PC). Seven Holstein bulls of 2.5-3 years of age were used in this experiment. Semen was collected via artificial vagina in one ejaculate per bull per week for the 7 week experimental period. Pooled semen was equally divided into three treatments using Tris extender. Combinations of vitamin C (2.5mM) were added with either catalase (100 IU/ml, T2) or reduced glutathione (2mM, T3) to Tris extender and comparisons in response were made with the control group (Tris extender, T1). Individual sperm motility (IM), viability (V), plasma membrane integrity (PMI), and acrosome integrity (AI) were assessed during all periods of the study along with Malondialdehyde (MDA) concentrations and freezing ability. The IM was greater (P ≤ 0.01) in the T2 as compared with the T1 group at all periods of the study. Furthermore, the IM were greater (P ≤ 0.01) in the T3 as compared with the T1 group at the 48 h time period and at 3 months PC. The V, PMI and AI were greater (P ≤ 0.01) in T2 and T3 as compared with the T1 group at all the experimental periods. The MDA was greater (P ≤ 0.01) in the T2 as compared with the T1 group at 3 months PC. In conclusion, there was improved semen quality if semen of Holstein bulls was collected and stored in combinations of vitamin C with either catalase (T2) or reduced glutathione (T3) being added to Tris extender. PMID:26861956

  9. relA over-expression reduces tumorigenicity and activates apoptosis in human cancer cells

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    Ricca, A; Biroccio, A; Trisciuoglio, D; Cippitelli, M; Zupi, G; Bufalo, D Del

    2001-01-01

    We previously demonstrated that bcl-2 over-expression increases the malignant behaviour of the MCF7 ADR human breast cancer cell line and enhances nuclear factor-kappa B (NF-k B) transcriptional activity. Here, we investigated the direct effect of increased NF-k B activity on the tumorigenicity of MCF7 ADR cells by over-expressing the NF-k B subunit relA/p65. Surprisingly, our results demonstrated that over-expression of relA determines a considerable reduction of the tumorigenic ability in nude mice as indicated by the tumour take and the median time of tumour appearance. In vitro studies also evidenced a reduced cell proliferation and the activation of the apoptotic programme after relA over-expression. Apoptosis was associated with the production of reactive oxygen species, and the cleavage of the specific substrate Poly-ADP-ribose-polymerrase. Our data indicate that there is no general role for NF-k B in the regulation of apoptosis and tumorigenicity. In fact, even though inhibiting NF-k B activity has been reported to be lethal to tumour cells, our findings clearly suggest that an over-induction of nuclear NF-k B activity may produce the same effect. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11747334

  10. Overexpression of the short endoglin isoform reduces renal fibrosis and inflammation after unilateral ureteral obstruction.

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    Muñoz-Félix, José M; Pérez-Roque, Lucía; Núñez-Gómez, Elena; Oujo, Bárbara; Arévalo, Miguel; Ruiz-Remolina, Laura; Cuesta, Cristina; Langa, Carmen; Pérez-Barriocanal, Fernando; Bernabeu, Carmelo; Lopez-Novoa, José M

    2016-09-01

    Transforming growth factor beta 1 (TGF-β1) is one of the most studied cytokines involved in renal tubulo-interstitial fibrosis, which is characterized by myofibroblast abundance and proliferation, and high buildup of extracellular matrix in the tubular interstitium leading to organ failure. Endoglin (Eng) is a 180-kDa homodimeric transmembrane protein that regulates a great number of TGF-β1 actions in different biological processes, including ECM synthesis. High levels of Eng have been observed in experimental models of renal fibrosis or in biopsies from patients with chronic kidney disease. In humans and mice, two Eng isoforms are generated by alternative splicing, L-Eng and S-Eng that differ in the length and composition of their cytoplasmic domains. We have previously described that L-Eng overexpression promotes renal fibrosis after unilateral ureteral obstruction (UUO). However, the role of S-Eng in renal fibrosis is unknown and its study would let us analyze the possible function of the cytoplasmic domain of Eng in this process. For this purpose, we have generated a mice strain that overexpresses S-Eng (S-ENG(+)) and we have performed an UUO in S-ENG(+) and their wild type (WT) control mice. Our results indicate that obstructed kidney of S-ENG(+) mice shows lower levels of tubulo-interstitial fibrosis, less inflammation and less interstitial cell proliferation than WT littermates. Moreover, S-ENG(+) mice show less activation of Smad1 and Smad2/3 pathways. Thus, S-Eng overexpression reduces UUO-induced renal fibrosis and some associated mechanisms. As L-Eng overexpression provokes renal fibrosis we conclude that Eng-mediated induction of renal fibrosis in this model is dependent on its cytoplasmic domain. PMID:27321931

  11. FHL1 reduces dystrophy in transgenic mice overexpressing FSHD muscular dystrophy region gene 1 (FRG1.

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    Sandra J Feeney

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is an autosomal-dominant disease with no effective treatment. The genetic cause of FSHD is complex and the primary pathogenic insult underlying the muscle disease is unknown. Several disease candidate genes have been proposed including DUX4 and FRG1. Expression analysis studies of FSHD report the deregulation of genes which mediate myoblast differentiation and fusion. Transgenic mice overexpressing FRG1 recapitulate the FSHD muscular dystrophy phenotype. Our current study selectively examines how increased expression of FRG1 may contribute to myoblast differentiation defects. We generated stable C2C12 cell lines overexpressing FRG1, which exhibited a myoblast fusion defect upon differentiation. To determine if myoblast fusion defects contribute to the FRG1 mouse dystrophic phenotype, this strain was crossed with skeletal muscle specific FHL1-transgenic mice. We previously reported that FHL1 promotes myoblast fusion in vitro and FHL1-transgenic mice develop skeletal muscle hypertrophy. In the current study, FRG1 mice overexpressing FHL1 showed an improvement in the dystrophic phenotype, including a reduced spinal kyphosis, increased muscle mass and myofiber size, and decreased muscle fibrosis. FHL1 expression in FRG1 mice, did not alter satellite cell number or activation, but enhanced myoblast fusion. Primary myoblasts isolated from FRG1 mice showed a myoblast fusion defect that was rescued by FHL1 expression. Therefore, increased FRG1 expression may contribute to a muscular dystrophy phenotype resembling FSHD by impairing myoblast fusion, a defect that can be rescued by enhanced myoblast fusion via expression of FHL1.

  12. Ecto-5'-Nucleotidase Overexpression Reduces Tumor Growth in a Xenograph Medulloblastoma Model.

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    Angélica R Cappellari

    Full Text Available Ecto-5'-nucleotidase/CD73 (ecto-5'-NT participates in extracellular ATP catabolism by converting adenosine monophosphate (AMP into adenosine. This enzyme affects the progression and invasiveness of different tumors. Furthermore, the expression of ecto-5'-NT has also been suggested as a favorable prognostic marker, attributing to this enzyme contradictory functions in cancer. Medulloblastoma (MB is the most common brain tumor of the cerebellum and affects mainly children.The effects of ecto-5'-NT overexpression on human MB tumor growth were studied in an in vivo model. Balb/c immunodeficient (nude 6 to 14-week-old mice were used for dorsal subcutaneous xenograph tumor implant. Tumor development was evaluated by pathophysiological analysis. In addition, the expression patterns of adenosine receptors were verified.The human MB cell line D283, transfected with ecto-5'-NT (D283hCD73, revealed reduced tumor growth compared to the original cell line transfected with an empty vector. D283hCD73 generated tumors with a reduced proliferative index, lower vascularization, the presence of differentiated cells and increased active caspase-3 expression. Prominent A1 adenosine receptor expression rates were detected in MB cells overexpressing ecto-5'-NT.This work suggests that ecto-5'-NT promotes reduced tumor growth to reduce cell proliferation and vascularization, promote higher differentiation rates and initiate apoptosis, supposedly by accumulating adenosine, which then acts through A1 adenosine receptors. Therefore, ecto-5'-NT might be considered an important prognostic marker, being associated with good prognosis and used as a potential target for therapy.

  13. Reduced grain chalkiness and its possible physiological mechanism in transgenic rice overexpressing l-GalLDH

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    Le Yu

    2015-04-01

    Full Text Available Chalkiness is one of the key factors determining rice quality and price. Ascorbic acid (Asc is a major plant antioxidant that performs many functions in plants. l-Galactono-1,4-lactone dehydrogenase (l-GalLDH, EC1.3.2.3 is an enzyme that catalyzes the final step of Asc biosynthesis in plants. Here we show that the l-GalLDH-overexpressing transgenic rice, GO-2, which has constitutively higher leaf Asc content than wild-type (WT plants, exhibits significantly reduced grain chalkiness. Higher foliar ascorbate/dehydroascorbate (Asc/DHA ratios at 40, 60, 80, and 100 days of plant age were observed in GO-2. Further investigation showed that the enhanced level of Asc resulted in a significantly higher ribulose-1,5-bisphosphate (RuBP carboxylase/oxygenase (Rubisco protein level in GO-2 at 80 days. In addition, levels of abscisic acid (ABA and jasmonic acid (JA were lower in GO-2 at 60, 80, and 100 days. The results we present here indicate that the enhanced level of Asc is likely responsible for changing redox homeostasis in key developmental stages associated with grain filling and alters grain chalkiness in the l-GalLDH-overexpressing transgenic by maintaining photosynthetic function and affecting phytohormones associated with grain filling.

  14. Hippocampal neuroligin-2 overexpression leads to reduced aggression and inhibited novelty reactivity in rats.

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    Christine Kohl

    Full Text Available Disturbances of the excitation/inhibition (E/I balance in the brain were recently suggested as potential factors underlying disorders like autism and schizophrenia resulting in associated behavioral alterations including changes in social and emotional behavior as well as abnormal aggression. Neuronal cell adhesion molecules (nCAMs and mutations in these genes were found to be strongly implicated in the pathophysiology of these disorders. Neuroligin2 (nlgn2 is a postsynaptic cell adhesion molecule, which is predominantly expressed at inhibitory synapses and required for synapse specification and stabilization. Changes in the expression of nlgn2 were shown to result in alterations of social behavior as well as altered inhibitory synaptic transmission, hence modifying the E/I balance. In our study, we focused on the role of nlgn2 in the dorsal hippocampus in the regulation of emotional and social behaviors. To this purpose, we injected an AAV construct overexpressing nlgn2 in the hippocampus of rats and investigated the effects on behavior and on markers for the E/I ratio. We could show an increase in GAD65, a GABA-synthesizing protein in neuronal terminals, and furthermore, reduced exploration of novel stimuli and less offensive behavior. Our data suggest nlgn2 in the hippocampus to be strongly implicated in maintaining the E/I balance in the brain and thereby modulating social and emotional behavior.

  15. relA over-expression reduces tumorigenicity and activates apoptosis in human cancer cells

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    Ricca, A; Biroccio, A; Trisciuoglio, D; M. Cippitelli; Zupi, G.; Bufalo, D Del

    2001-01-01

    We previously demonstrated that bcl-2 over-expression increases the malignant behaviour of the MCF7 ADR human breast cancer cell line and enhances nuclear factor-kappa B (NF-k B) transcriptional activity. Here, we investigated the direct effect of increased NF-k B activity on the tumorigenicity of MCF7 ADR cells by over-expressing the NF-k B subunit relA/p65. Surprisingly, our results demonstrated that over-expression of relA determines a considerable reduction of the tumorigenic ability in n...

  16. bcl-xl over-expression in transgenic mice reduces cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Furong Wang; Yongsheng Jiang; Yan Liu; Wenwu Xiao; Suming Zhang

    2008-01-01

    reperfusion, cerebral infarct volume was reduced by 30% in bcl-xl transgenic mice compared with wild-type mice. Simultaneously, the number of apoptotic cells in the ischemic cerebral cortex was significantly less in the transgenic mice compared with the wild-type mice. Overall, the number of apoptotic cells in the transgenic mice remained at a relatively low level. Prior to and subsequent to cerebral ischemia/reperfusion, transgenic mice exhibited markedly higher Bcl-xl protein levels compared with wild-type mice. In addition, after reperfusion, the level of Bcl-xl protein was increased in both transgenic and wild-type mice, but there was no significant difference (P > 0.05) between the two groups. The level of cytochrome C in the transgenic mice was low in the first 24 hours after reperfusion and increased thereafter but was still lower compared with wild-type mice. Neurological function scores demonstrated that transgenic mice exhibited milder neurological function impairment compared with wild-type mice. CONCLUSION: bcl-xl over-expression can inhibit cytochrome C release and result in an inhibitory effect on neural cell apoptosis, thereby alleviating neural cell injury. This is likely to occur due to exogenous over-expression of bcl-xl rather than endogenous production of bcl-xl.

  17. Glyoxalase-1 overexpression reduces endothelial dysfunction and attenuates early renal impairment in a rat model of diabetes

    DEFF Research Database (Denmark)

    Brouwers, Olaf; Niessen, Petra M G; Miyata, Toshio; Østergaard, Jakob A; Flyvbjerg, Allan; Peutz-Kootstra, Carine J; Sieber, Jonas; Mundel, Peter H; Brownlee, Michael; Janssen, Ben J A; De Mey, Jo; Stehouwer, Coen D A; Schalkwijk, Casper G

    2014-01-01

    the MGO-detoxifying enzyme glyoxalase-I (GLO-I), to determine the impact of intracellular glycation on vascular function and the development of early renal changes in diabetes. METHODS: Wild-type and Glo1-overexpressing rats were rendered diabetic for a period of 24 weeks by intravenous injection of...... measured with ELISA-based techniques. RESULTS: Diabetes-induced formation of AGEs in mesenteric arteries and endothelial dysfunction were reduced by Glo1 overexpression. Despite the absence of advanced nephrotic lesions, early markers of renal dysfunction (i.e. increased glomerular volume, decreased...

  18. Overexpression of TGF-ß1 in macrophages reduces and stabilizes atherosclerotic plaques in ApoE-deficient mice.

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    Kurt Reifenberg

    Full Text Available Although macrophages represent the hallmark of both human and murine atherosclerotic lesions and have been shown to express TGF-ß1 (transforming growth factor β1 and its receptors, it has so far not been experimentally addressed whether the pleiotropic cytokine TGF-ß1 may influence atherogenesis by a macrophage specific mechanism. We developed transgenic mice with macrophage specific TGF-ß1 overexpression, crossed the transgenics to the atherosclerotic ApoE (apolipoprotein E knock-out strain and quantitatively analyzed both atherosclerotic lesion development and composition of the resulting double mutants. Compared with control ApoE(-/- mice, animals with macrophage specific TGF-ß1 overexpression developed significantly less atherosclerosis after 24 weeks on the WTD (Western type diet as indicated by aortic plaque area en face (p<0.05. Reduced atherosclerotic lesion development was associated with significantly less macrophages (p<0.05 after both 8 and 24 weeks on the WTD, significantly more smooth muscle cells (SMCs; p<0.01 after 24 weeks on the WTD, significantly more collagen (p<0.01 and p<0.05 after 16 and 24 weeks on the WTD, respectively without significant differences of inner aortic arch intima thickness or the number of total macrophages in the mice pointing to a plaque stabilizing effect of macrophage-specific TGF-ß1 overexpression. Our data shows that macrophage specific TGF-ß1 overexpression reduces and stabilizes atherosclerotic plaques in ApoE-deficient mice.

  19. FHL1 Reduces Dystrophy in Transgenic Mice Overexpressing FSHD Muscular Dystrophy Region Gene 1 (FRG1)

    OpenAIRE

    Feeney, Sandra J.; McGrath, Meagan J.; Absorn Sriratana; Stefan M Gehrig; Gordon S Lynch; Colleen E D'Arcy; John T Price; McLean, Catriona A.; Rossella Tupler; Mitchell, Christina A.

    2015-01-01

    Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal-dominant disease with no effective treatment. The genetic cause of FSHD is complex and the primary pathogenic insult underlying the muscle disease is unknown. Several disease candidate genes have been proposed including DUX4 and FRG1. Expression analysis studies of FSHD report the deregulation of genes which mediate myoblast differentiation and fusion. Transgenic mice overexpressing FRG1 recapitulate the FSHD muscular dystrophy phe...

  20. Reducing Both Pgp Overexpression and Drug Efflux with Anti-Cancer Gold-Paclitaxel Nanoconjugates

    Science.gov (United States)

    Li, Fei; Zhou, Xiaofei; Zhou, Hongyu; Jia, Jianbo; Li, Liwen; Zhai, Shumei; Yan, Bing

    2016-01-01

    Repeated administrations of anti-cancer drugs to patients often induce drug resistance. P-glycoprotein (Pgp) facilitates an efficient drug efflux, preventing cellular accumulation of drugs and causing multi-drug resistance (MDR). In this study, we developed a gold-paclitaxel nanoconjugate system to overcome MDR. Gold nanoparticles (GNPs) were conjugated with β-cyclodextrin enclosing paclitaxel (PTX) molecules and PEG molecules. GNP conjugates were effectively endocytosed by both drug-sensitive human lung cancer H460 cells and Pgp-overexpressed drug-resistant H460PTX cells. Compared with PTX, PGNPs did not induce the Pgp overexpression in drug-sensitive H460 cells after long-term treatment and also avoided being pumped out of cells by overexpressed Pgp molecules in H460PTX with a 17-fold lower EC50 compared to PTX. Fluorescent microscopy and flow cytometry further confirmed that fluorescent labeled PGNPs (f-PGNPs) maintained a high cellular PTX level in both H460 and H460PTX cells. These results demonstrated that nano-drug conjugates were able to avoid the development of drug resistance in sensitive cells and evade Pgp-mediated drug resistance and to maintain a high cytotoxicity in drug-resistant cancer cells. These findings exemplify a powerful nanotechnological approach to the long-lasting issue of chemotherapy-induced drug resistance. PMID:27467397

  1. Overexpression of extracellular superoxide dismutase reduces acute radiation induced lung toxicity

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    Golson Maria L

    2005-06-01

    Full Text Available Abstract Background Acute RT-induced damage to the lung is characterized by inflammatory changes, which proceed to the development of fibrotic lesions in the late phase of injury. Ultimately, complete structural ablation will ensue, if the source of inflammatory / fibrogenic mediators and oxidative stress is not removed or attenuated. Therefore, the purpose of this study is to determine whether overexpression of extracellular superoxide dismutase (EC-SOD in mice ameliorates acute radiation induced injury by inhibiting activation of TGFβ1 and downregulating the Smad 3 arm of its signal transduction pathway. Methods Whole thorax radiation (single dose, 15 Gy was delivered to EC-SOD overexpressing transgenic (XRT-TG and wild-type (XRT-WT animals. Mice were sacrificed at 1 day, 1 week, 3, 6, 10 and 14 weeks. Breathing rates, right lung weights, total/differential leukocyte count, activated TGFβ1 and components of its signal transduction pathway (Smad 3 and p-Smad 2/3 were assessed to determine lung injury. Results Irradiated wild-type (XRT-WT animals exhibited time dependent increase in breathing rates and right lung weights, whereas these parameters were significantly less increased (p vs. XRT-WT. Conclusion This study shows that overexpression of EC-SOD confers protection against RT-induced acute lung injury. EC-SOD appears to work, in part, via an attenuation of the macrophage response and also decreases TGFβ1 activation with a subsequent downregulation of the profibrotic TGFβ pathway.

  2. SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario

    International Nuclear Information System (INIS)

    We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCP1, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer. - Highlights: • SET, UCPs and autophagy prevention are correlated. • SET action has mitochondrial involvement. • UCP2/3 may reduce ROS and prevent autophagy. • SET protects cell from ROS via UCP2/3

  3. SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Luciana O.; Goto, Renata N. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Neto, Marinaldo P.C. [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Sousa, Lucas O. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Curti, Carlos [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Leopoldino, Andréia M., E-mail: andreiaml@usp.br [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

    2015-03-06

    We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCP1, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer. - Highlights: • SET, UCPs and autophagy prevention are correlated. • SET action has mitochondrial involvement. • UCP2/3 may reduce ROS and prevent autophagy. • SET protects cell from ROS via UCP2/3.

  4. Liver-specific overexpression of LPCAT3 reduces postprandial hyperglycemia and improves lipoprotein metabolic profile in mice.

    Science.gov (United States)

    Cash, J G; Hui, D Y

    2016-01-01

    Previous studies have shown that group 1B phospholipase A2-mediated absorption of lysophospholipids inhibits hepatic fatty acid β-oxidation and contributes directly to postprandial hyperglycemia and hyperlipidemia, leading to increased risk of cardiometabolic disease. The current study tested the possibility that increased expression of lysophosphatidylcholine acyltransferase-3 (LPCAT3), an enzyme that converts lysophosphatidylcholine to phosphatidylcholine in the liver, may alleviate the adverse effects of lysophospholipids absorbed after a lipid-glucose mixed meal. The injection of an adenovirus vector harboring the human LPCAT3 gene into C57BL/6 mice increased hepatic LPCAT3 expression fivefold compared with mice injected with a control LacZ adenovirus. Postprandial glucose tolerance tests after feeding these animals with a bolus lipid-glucose mixed meal revealed that LPCAT3 overexpression improved postprandial hyperglycemia and glucose tolerance compared with control mice with LacZ adenovirus injection. Mice with LPCAT3 overexpression also showed reduced very low density lipoprotein production and displayed elevated levels of the metabolic- and cardiovascular-protective large apoE-rich high density lipoproteins in plasma. The mechanism underlying the metabolic benefits of LPCAT3 overexpression was shown to be due to the alleviation of lysophospholipid inhibition of fatty acid β-oxidation in hepatocytes. Taken together, these results suggest that specific LPCAT3 induction in the liver may be a viable strategy for cardiometabolic disease intervention. PMID:27110687

  5. Reducing acetate excretion from E. coli K-12 by over-expressing the small RNA sgrS

    OpenAIRE

    Negrete, Alejandro; Majdalani, Nadim; Phue, Je Nie; Shiloach, Joseph

    2011-01-01

    When exposed to the non-metabolized glucose derivative alpha methyl glucoside, both E. coli K-12 (JM109 and MG1655) and E. coli B (BL21) respond by reducing the concentration of the mRNA of the ptsG gene which is responsible for the biosynthesis of the glucose transporter EIICBglu. This occurs through the over-expression of the non-coding small RNA SgrS, which interacts specifically with the mRNA of the ptsG gene and prevents its translation. However, when these bacteria are exposed to a gluc...

  6. Overexpression of Jazf1 reduces body weight gain and regulates lipid metabolism in high fat diet

    International Nuclear Information System (INIS)

    Highlights: • The expression of Jazf1 in the liver suppressed lipid accumulation. • Jazf1 significantly increases transcription of fatty acid synthase. • Jazf1 plays a critical role in the regulation of energy and lipid homeostasis. • Jazf1 associates the development of metabolic disorder. • Jazf1 may provide a new therapeutic target in the management of metabolic disorder. - Abstract: Jazf1 is a 27 kDa nuclear protein containing three putative zinc finger motifs that is associated with diabetes mellitus and prostate cancer; however, little is known about the role that this gene plays in regulation of metabolism. Recent evidence indicates that Jazf1 transcription factors bind to the nuclear orphan receptor TR4. This receptor regulates PEPCK, the key enzyme involved in gluconeogenesis. To elucidate Jazf1’s role in metabolism, we fed a 60% fat diet for up to 15 weeks. In Jazf1 overexpression mice, weight gain was found to be significantly decreased. The expression of Jazf1 in the liver also suppressed lipid accumulation and decreased droplet size. These results suggest that Jazf1 plays a critical role in the regulation of lipid homeostasis. Finally, Jazf1 may provide a new therapeutic target in the management of obesity and diabetes

  7. Overexpression of Jazf1 reduces body weight gain and regulates lipid metabolism in high fat diet

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Woo Young; Bae, Ki Beom; Kim, Sung Hyun; Yu, Dong Hun; Kim, Hei Jung; Ji, Young Rae; Park, Seo Jin; Park, Si Jun; Kang, Min-Cheol; Jeong, Ja In [School of Life Science and Biotechnology, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701 (Korea, Republic of); Park, Sang-Joon [College of Veterinary Medicine, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701 (Korea, Republic of); Lee, Sang Gyu [School of Life Science and Biotechnology, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701 (Korea, Republic of); Lee, Inkyu [School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 700-842 (Korea, Republic of); Kim, Myoung Ok [School of Animal BT Sciences, Sangju Campus, Kyungpook National University, 386 Gajang-dong, Sangju, Gyeongsangbuk-do 742-211 (Korea, Republic of); Yoon, Duhak, E-mail: dhyoon@knu.ac.kr [School of Animal BT Sciences, Sangju Campus, Kyungpook National University, 386 Gajang-dong, Sangju, Gyeongsangbuk-do 742-211 (Korea, Republic of); Ryoo, Zae Young, E-mail: jaewoong64@hanmail.net [School of Life Science and Biotechnology, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701 (Korea, Republic of)

    2014-02-14

    Highlights: • The expression of Jazf1 in the liver suppressed lipid accumulation. • Jazf1 significantly increases transcription of fatty acid synthase. • Jazf1 plays a critical role in the regulation of energy and lipid homeostasis. • Jazf1 associates the development of metabolic disorder. • Jazf1 may provide a new therapeutic target in the management of metabolic disorder. - Abstract: Jazf1 is a 27 kDa nuclear protein containing three putative zinc finger motifs that is associated with diabetes mellitus and prostate cancer; however, little is known about the role that this gene plays in regulation of metabolism. Recent evidence indicates that Jazf1 transcription factors bind to the nuclear orphan receptor TR4. This receptor regulates PEPCK, the key enzyme involved in gluconeogenesis. To elucidate Jazf1’s role in metabolism, we fed a 60% fat diet for up to 15 weeks. In Jazf1 overexpression mice, weight gain was found to be significantly decreased. The expression of Jazf1 in the liver also suppressed lipid accumulation and decreased droplet size. These results suggest that Jazf1 plays a critical role in the regulation of lipid homeostasis. Finally, Jazf1 may provide a new therapeutic target in the management of obesity and diabetes.

  8. Overexpression of a Potato Sucrose Synthase Gene in Cotton Accelerates Leaf Expansion,Reduces Seed Abortion, and Enhances Fiber Production

    Institute of Scientific and Technical Information of China (English)

    Shou-Min Xu; Elizabeth Brill; Danny J.Llewellyn; Robert T.Furbank; Yong-Ling Ruan

    2012-01-01

    Sucrose synthase (Sus) is a key enzyme in the breakdown of sucrose and is considered a biochemical marker for sink strength,especially in crop species,based on mutational and gene suppression studies.It remains elusive,however,whether,or to what extent,increase in Sus activity may enhance sink development.We aimed to address this question by expressing a potato Sus gene in cotton where Sus expression has been previously shown to be critical for normal seed and fiber development.Segregation analyses at T1 generation followed by studies in homozygous progeny lines revealed that increased Sus activity in cotton (1) enhanced leaf expansion with the effect evident from young leaves emerging from shoot apex; (2) improved early seed development,which reduced seed abortion,hence enhanced seed set,and (3) promoted fiber elongation.In young leaves of Sus overexpressing lines,fructose concentrations were significantly increased whereas,in elongating fibers,both fructose and glucose levels were increased.Since hexoses contribute little to osmolality in leaves,in contrast to developing fibers,it is concluded that high Sus activity promotes leaf development independently of osmotic regulation,probably through sugar signaling.The analyses also showed that doubling the Sus activity in 0-d cotton seeds increased their fresh weight by about 30%.However,further increase in Sus activity did not lead to any further increase in seed weight,indicating an upper limit for the Sus overexpression effect.Finally,based on the observed additive effect on fiber yield from increased fiber length and seed number,a new strategy is proposed to increase cotton fiber yield by improving seed development as a whole,rather than solely focusing on manipulating fiber growth.

  9. Overexpression and Constitutive Nuclear Localization of Cohesin Protease Separase Protein Correlates with High Incidence of Relapse and Reduced Overall Survival in Glioblastoma Multiforme

    Science.gov (United States)

    Mukherjee, Malini; Byrd, Tiara; Brawley, Vita S.; Bielamowicz, Kevin; Li, Xiao-Nan; Merchant, Fatima; Maitra, Saurabh; Sumazin, Pavel; Fuller, Greg; Kew, Yvonne; Sun, David; Powell, Suzanne Z.; Ahmed, Nabil M.; Zhang, Nenggang; Pati, Debananda

    2014-01-01

    Separase, an enzyme that cleaves the chromosomal cohesin during mitosis, is overexpressed in a wide range of human epithelial cancers of breast, bone and prostate [Meyer et al, 2009, Clin Cancer Res 15(8): 2703-2710] [1]. Overexpression of Separase in animal models results in aneuploidy and tumorigenesis. We have examined the expression and localization of Separase protein in adult and pediatric glioblastoma and normal brain specimens. Immunofluorescence microscopy and Western blot analysis showed significant overexpression of Separase in all adult and a subset of pediatric glioblastoma cells. Tumor status and patient survival strongly correlate with the mislocalization of Separase into the nucleus throughout all stages of the cell cycle. Unlike exclusively nuclear localization in mitotic control cells, glioblastoma samples have a significantly higher number of resting (interphase) cells with strong nuclear Separase staining. Additionally, patient survival analysis demonstrated a strong correlation between overexpression of Separase protein in adult glioblastoma and a high incidence of relapse and reduced overall survival. These results further strengthen our hypothesis that Separase is an oncogene whose overexpression induces tumorigenesis, and indicate that Separase overexpression and aberrant nuclear localization are common in many tumor types and may predict outcome in some human malignancies. PMID:24792645

  10. PGC-1α Serine 570 Phosphorylation and GCN5-mediated Acetylation by Angiotensin II Drive Catalase Down-regulation and Vascular Hypertrophy*

    Science.gov (United States)

    Xiong, Shiqin; Salazar, Gloria; San Martin, Alejandra; Ahmad, Mushtaq; Patrushev, Nikolay; Hilenski, Lula; Nazarewicz, Rafal Robert; Ma, Minhui; Ushio-Fukai, Masuko; Alexander, R. Wayne

    2010-01-01

    Angiotensin II (Ang II) is a pleuripotential hormone that is important in the pathophysiology of multiple conditions including aging, cardiovascular and renal diseases, and insulin resistance. Reactive oxygen species (ROS) are important mediators of Ang II-induced signaling generally and have a well defined role in vascular hypertrophy, which is inhibited by overexpression of catalase, inferring a specific role of H2O2. The molecular mechanisms are understood incompletely. The transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a key regulator of energy metabolism and ROS-scavenging enzymes including catalase. We show that Ang II stimulates Akt-dependent PGC-1α serine 570 phosphorylation, which is required for the binding of the histone acetyltransferase GCN5 (general control nonderepressible 5) to PGC-1α and for its lysine acetylation. These sequential post-translational modifications suppress PGC-1α activity and prevent its binding to the catalase promoter through the forkhead box O1 transcription factor, thus decreasing catalase expression. We demonstrate that overexpression of the phosphorylation-defective mutant PGC-1α (S570A) prevents Ang II-induced increases in H2O2 levels and hypertrophy ([3H]leucine incorporation). Knockdown of PGC-1α by small interfering RNA promotes basal and Ang II-stimulated ROS and hypertrophy, which is reversed by polyethylene glycol-conjugated catalase. Thus, endogenous PGC-1α is a negative regulator of vascular hypertrophy by up-regulating catalase expression and thus reducing ROS levels. We provide novel mechanistic insights by which Ang II may mediate its ROS-dependent pathophysiologic effects on multiple cardiometabolic diseases. PMID:19940161

  11. Overexpression of rice NAC gene SNAC1 improves drought and salt tolerance by enhancing root development and reducing transpiration rate in transgenic cotton.

    Directory of Open Access Journals (Sweden)

    Guanze Liu

    Full Text Available The SNAC1 gene belongs to the stress-related NAC superfamily of transcription factors. It was identified from rice and overexpressed in cotton cultivar YZ1 by Agrobacterium tumefaciens-mediated transformation. SNAC1-overexpressing cotton plants showed more vigorous growth, especially in terms of root development, than the wild-type plants in the presence of 250 mM NaCl under hydroponic growth conditions. The content of proline was enhanced but the MDA content was decreased in the transgenic cotton seedlings under drought and salt treatments compared to the wild-type. Furthermore, SNAC1-overexpressing cotton plants also displayed significantly improved tolerance to both drought and salt stresses in the greenhouse. The performances of the SNAC1-overexpressing lines under drought and salt stress were significantly better than those of the wild-type in terms of the boll number. During the drought and salt treatments, the transpiration rate of transgenic plants significantly decreased in comparison to the wild-type, but the photosynthesis rate maintained the same at the flowering stage in the transgenic plants. These results suggested that overexpression of SNAC1 improve more tolerance to drought and salt in cotton through enhanced root development and reduced transpiration rates.

  12. CTT1 overexpression increases life span of calorie-restricted Saccharomyces cerevisiae deficient in Sod1.

    Science.gov (United States)

    Rona, Germana; Herdeiro, Ricardo; Mathias, Cristiane Juliano; Torres, Fernando Araripe; Pereira, Marcos Dias; Eleutherio, Elis

    2015-06-01

    Studies using different organisms revealed that reducing calorie intake, without malnutrition, known as calorie restriction (CR), increases life span, but its mechanism is still unkown. Using the yeast Saccharomyces cerevisiae as eukaryotic model, we observed that Cu, Zn-superoxide dismutase (Sod1p) is required to increase longevity, as well as to confer protection against lipid and protein oxidation under CR. Old cells of sod1 strain also presented a premature induction of apoptosis. However, when CTT1 (which codes for cytosolic catalase) was overexpressed, sod1 and WT strains showed similar survival rates. Furthermore, CTT1 overexpression decreased lipid peroxidation and delayed the induction of apoptotic process. Superoxide is rapidly converted to hydrogen peroxide by superoxide dismutase, but it also undergoes spontaneous dismutation albeit at a slower rate. However, the quantity of peroxide produced from superoxide in this way is two-fold higher. Peroxide degradation, catalyzed by catalase, is of vital importance, because in the presence of a reducer transition metal peroxide is reduced to the highly reactive hydroxyl radical, which reacts indiscriminately with most cellular constituents. These findings might explain why overexpression of catalase was able to overcome the deficiency of Sod1p, increasing life span in response to CR. PMID:25573485

  13. Peroxisomal catalase deficiency modulates yeast lifespan depending on growth conditions

    OpenAIRE

    Kawalek, Adam; Lefevre, Sophie D.; Veenhuis, Marten; van der Klei, Ida J.

    2013-01-01

    We studied the role of peroxisomal catalase in chronological aging of the yeast Hansenula polymorpha in relation to various growth substrates. Catalase-deficient (cat) cells showed a similar chronological life span (CLS) relative to the wild-type control upon growth on carbon and nitrogen sources that are not oxidized by peroxisomal enzymes. However, when media contained methylamine, which is oxidized by peroxisomal amine oxidase, the CLS of cat cells was significantly reduced. Conversely, th...

  14. Overexpression of carnitine palmitoyltransferase I in skeletal muscle in vivo increases fatty acid oxidation and reduces triacylglycerol esterification

    NARCIS (Netherlands)

    Bruce, Clinton R.; Brolin, Camilla; Turner, Nigel; Cleasby, Mark E.; van der Leij, Feike R.; Cooney, Gregory J.; Kraegen, Edward W.

    2007-01-01

    A key regulatory point in the control of fatty acid ( FA) oxidation is thought to be transport of FAs across the mitochondrial membrane by carnitine palmitoyltransferase I (CPT I). To investigate the role of CPT I in FA metabolism, we used in vivo electrotransfer (IVE) to locally overexpress CPT I i

  15. CPT1α over-expression increases long-chain fatty acid oxidation and reduces cell viability with incremental palmitic acid concentration in 293T cells

    International Nuclear Information System (INIS)

    To test the cellular response to an increased fatty acid oxidation, we generated a vector for an inducible expression of the rate-limiting enzyme carnitine palmitoyl-transferase 1α (CPT1α). Human embryonic 293T kidney cells were transiently transfected and expression of the CPT1α transgene in the tet-on vector was activated with doxycycline. Fatty acid oxidation was measured by determining the conversion of supplemented, synthetic cis-10-heptadecenoic acid (C17:1n-7) to C15:ln-7. CPT1α over-expression increased mitochondrial long-chain fatty acid oxidation about 6-fold. Addition of palmitic acid (PA) decreased viability of CPT1α over-expressing cells in a concentration-dependent manner. Both, PA and CPT1α over-expression increased cell death. Interestingly, PA reduced total cell number only in cells over-expressing CPT1α, suggesting an effect on cell proliferation that requires PA translocation across the mitochondrial inner membrane. This inducible expression system should be well suited to study the roles of CPT1 and fatty acid oxidation in lipotoxicity and metabolism in vivo

  16. Overexpression of KiSS-1 reduces colorectal cancer cell invasion by downregulating MMP-9 via blocking PI3K/Akt/NF-κB signal pathway.

    Science.gov (United States)

    Chen, Shaoqin; Chen, Wei; Zhang, Xiang; Lin, Suyong; Chen, Zhihua

    2016-04-01

    Metastasis of colorectal cancer (CRC) depends critically on MMP-9. KiSS-1 is a human malignant melanoma metastasis-suppressor gene. Thus, the interaction between MMP-9 and KiSS-1 has drawn considerable attention in recent years. In the present study, it was hypothesized that KiSS-1 gene could repress the metastatic potential of colorectal cancer cells by inhibiting the expression of MMP-9. Stable transfection of KiSS-1 specific siRNA and KiSS-1 expression vector in human CRC cell line HCT-116 was achieved by lentivirus infection. Moreover, the cell proliferation, invasiveness, and apoptosis were evaluated by CCK-8 method, transwell experiment, and fluorescence activated cell sorter, respectively. We also investigated the expression of MMP-9, PI3K, Akt, pAKt, and NF-кB subunit p65 using western blotting. KiSS-1 overexpression significantly decreased the cell proliferation and invasiveness of HCT-119 cells, while apoptosis was enhanced. The result of western blotting showed that synthesis of MMP-9, PI3K, p65, and phosphorylation of Akt were significantly blocked by overexpression of KiSS-1. Concatenated treatment of KiSS-1 overexpression vector with PI3K and Akt agonists attenuated the effect of KiSS-1 on the biological activity of CRC cells and also released the expression of MMP-9, PI3K, p65, and phosphorylation of Akt from the influence of overexpression of KiSS-1. Overexpression of KiSS-1 suppressed the invasiveness of CRC cells, and the gene exerted its function by reducing the expression of MMP-9 via blocking of tge PI3K/Akt/NF-κB pathway. PMID:26847533

  17. Overexpression of Rice Sphingosine-1-Phoshpate Lyase Gene OsSPL1 in Transgenic Tobacco Reduces Salt and Oxidative Stress Tolerance

    Institute of Scientific and Technical Information of China (English)

    Huijuan Zhang; Jing Zhai; Jibo Mo; Dayong Li; Fengming Song

    2012-01-01

    Sphingolipids,including sphingosine-1-phosphate (S1P),have been shown to function as signaling mediators to regulate diverse aspects of plant growth,development,and stress response.In this study,we performed functional analysis of a rice (Oryza sativa) S1P lyase gene OsSPL1 in transgenic tobacco plants and explored its possible involvement in abiotic stress response.Overexpression of OsSPL1 in transgenic tobacco resulted in enhanced sensitivity to exogenous abscisic acid (ABA),and decreased tolerance to salt and oxidative stress,when compared with the wild type.Furthermore,the expression levels of some selected stress-related genes in OsSPL1-overexpressing plants were reduced after application of salt or oxidative stress,indicating that the altered responsiveness of stress-related genes may be responsible for the reduced tolerance in OsSPL1-overexpressing tobacco plants under salt and oxidative stress.Our results suggest that rice OsSPL1 plays an important role in abiotic stress responses.

  18. Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice.

    Directory of Open Access Journals (Sweden)

    Sindhu K Madathil

    Full Text Available Traumatic brain injury (TBI survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1, a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal overexpression of IGF-1 using the controlled cortical impact (CCI injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.

  19. Overexpression of DJ-1 reduces oxidative stress and attenuates hypoxia/reoxygenation injury in NRK-52E cells exposed to high glucose

    Science.gov (United States)

    Shen, Zi-Ying; Sun, Qian; Xia, Zhong-Yuan; Meng, Qing-Tao; Lei, Shao-Qing; Zhao, Bo; Tang, Ling-Hua; Xue, Rui; Chen, Rong

    2016-01-01

    Patients with diabetes are more vulnerable to renal ischemia/reperfusion (I/R) injury, which is implicated in hyperglycemia-induced oxidative stress. We previously reported that the hyperglycemia-induced inhibition of DJ-1, a novel oncogene that exhibits potent antioxidant activity, is implicated in the severity of myocardial I/R injury. In the present study, we aimed to explore the role of DJ-1 in hypoxia/reoxygenation (H/R) injury in renal cells exposed to high glucose (HG). For this purpose, NRK-52E cells were exposed to HG (30 mM) for 48 h and then exposed to hypoxia for 4 h and reoxygenation for 2 h, which significantly decreased cell viability and superoxide dismutase (SOD) activity, and increased the malondialdehyde (MDA) content, accompanied by a decrease in DJ-1 protein expression. The overexpression of DJ-1 by transfection with a DJ-1 overexpression plasmid exerted protective effects against HG-induced H/R injury, as evidenced by increased CCK-8 levels and SOD activity, the decreased release of lactate dehydrogenase (LDH) and the decreased MDA content, and increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. Similar effects were observed following treatment with the antioxidant, N-acetylcysteine. These results suggest that the overexpression of DJ-1 reduces oxidative stress and attenuates H/R injury in NRK-52E cells exposed to HG. PMID:27430285

  20. Cysteine-independent Catalase-like Activity of Vertebrate Peroxiredoxin 1 (Prx1).

    Science.gov (United States)

    Sun, Cen-Cen; Dong, Wei-Ren; Zhao, Jing; Nie, Li; Xiang, Li-Xin; Zhu, Guan; Shao, Jian-Zhong

    2015-08-01

    Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins that are known as thioredoxin peroxidases. Here we report that Prx1 proteins from Tetraodon nigroviridis and humans also possess a previously unknown catalase-like activity that is independent of Cys residues and reductants but dependent on iron. We identified that the GVL motif was essential to the catalase (CAT)-like activity of Prx1 but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and we generated mutants lacking POX and/or CAT activities for individually delineating their functional features. We discovered that the TnPrx1 POX and CAT activities possessed different kinetic features in reducing H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species and p38 phosphorylation in HEK-293T cells treated with H2O2. These observations suggest that the dual antioxidant activities of Prx1 may be crucial for organisms to mediate intracellular redox homeostasis. PMID:26088136

  1. Acetoacetate reduces growth and ATP concentration in cancer cell lines which over-express uncoupling protein 2

    Directory of Open Access Journals (Sweden)

    Quadros Edward V

    2009-05-01

    Full Text Available Abstract Background Recent evidence suggests that several human cancers are capable of uncoupling of mitochondrial ATP generation in the presence of intact tricarboxylic acid (TCA enzymes. The goal of the current study was to test the hypothesis that ketone bodies can inhibit cell growth in aggressive cancers and that expression of uncoupling protein 2 is a contributing factor. The proposed mechanism involves inhibition of glycolytic ATP production via a Randle-like cycle while increased uncoupling renders cancers unable to produce compensatory ATP from respiration. Methods Seven aggressive human cancer cell lines, and three control fibroblast lines were grown in vitro in either 10 mM glucose medium (GM, or in glucose plus 10 mM acetoacetate [G+AcA]. The cells were assayed for cell growth, ATP production and expression of UCP2. Results There was a high correlation of cell growth with ATP concentration (r = 0.948 in a continuum across all cell lines. Controls demonstrated normal cell growth and ATP with the lowest density of mitochondrial UCP2 staining while all cancer lines demonstrated proportionally inhibited growth and ATP, and over-expression of UCP2 (p Conclusion Seven human cancer cell lines grown in glucose plus acetoacetate medium showed tightly coupled reduction of growth and ATP concentration. The findings were not observed in control fibroblasts. The observed over-expression of UCP2 in cancer lines, but not in controls, provides a plausible molecular mechanism by which acetoacetate spares normal cells but suppresses growth in cancer lines. The results bear on the hypothesized potential for ketogenic diets as therapeutic strategies.

  2. Overexpression of GhWRKY27a reduces tolerance to drought stress and resistance to Rhizoctonia solani infection in transgenic Nicotiana benthamiana.

    Science.gov (United States)

    Yan, Yan; Jia, Haihong; Wang, Fang; Wang, Chen; Liu, Shuchang; Guo, Xingqi

    2015-01-01

    WRKY proteins constitute transcriptional regulators involved in various biological processes, especially in coping with diverse biotic and abiotic stresses. However, in contrast to other well-characterized WRKY groups, the functions of group III WRKY transcription factors are poorly understood in the economically important crop cotton (Gossypium hirsutum). In this study, a group III WRKY gene from cotton, GhWRKY27a, was isolated and characterized. Our data indicated that GhWRKY27a localized to the nucleus and that GhWRKY27a expression could be strongly induced by abiotic stresses, pathogen infection, and multiple defense-related signaling molecules. Virus-induced gene silencing (VIGS) of GhWRKY27a enhanced tolerance to drought stress in cotton. In contrast, GhWRKY27a overexpression in Nicotiana benthamiana markedly reduced plant tolerance to drought stress, as determined through physiological analyses of leaf water loss, survival rates, and the stomatal aperture. This susceptibility was coupled with reduced stomatal closure in response to abscisic acid and decreased expression of stress-related genes. In addition, GhWRKY27a-overexpressing plants exhibited reduced resistance to Rhizoctonia solani infection, mainly demonstrated by the transgenic lines exhibiting more severe disease symptoms, accompanied by attenuated expression of defense-related genes in N. benthamiana. Taken together, these findings indicated that GhWRKY27a functions in negative responses to drought tolerance and in resistance to R. solani infection. PMID:26483697

  3. Overexpression of GhWRKY27a reduces tolerance to drought stress and resistance to Rhizoctonia solani infection in transgenic Nicotiana benthamiana

    Directory of Open Access Journals (Sweden)

    Yan Yan

    2015-09-01

    Full Text Available WRKY proteins constitute transcriptional regulators involved in various biological processes, especially in coping with diverse biotic and abiotic stresses. However, in contrast to other well-characterized WRKY groups, the functions of group III WRKY transcription factors are poorly understood in the economically important crop cotton (Gossypium hirsutum. In this study, a group III WRKY gene from cotton, GhWRKY27a, was isolated and characterized. Our data indicated that GhWRKY27a localized to the nucleus and that GhWRKY27a expression could be strongly induced by abiotic stresses, pathogen infection, and multiple defense-related signaling molecules. Virus-induced gene silencing (VIGS of GhWRKY27a enhanced tolerance to drought stress in cotton. In contrast, GhWRKY27a overexpression in Nicotiana benthamiana markedly reduced plant tolerance to drought stress, as determined through physiological analyses of leaf water loss, survival rates and the stomatal aperture. This susceptibility was coupled with reduced stomatal closure in response to abscisic acid and decreased expression of stress-related genes. In addition, GhWRKY27a-overexpressing plants exhibited reduced resistance to Rhizoctonia solani infection, mainly demonstrated by the transgenic lines exhibiting more severe disease symptoms, accompanied by attenuated expression of defense-related genes in Nicotiana benthamiana. Taken together, these findings indicated that GhWRKY27a functions in negative responses to drought tolerance and in resistance to Rhizoctonia solani infection.

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

    Directory of Open Access Journals (Sweden)

    Xinhua Fu

    2014-01-01

    Full Text Available 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.

  5. Overexpression of the calpain-specific inhibitor calpastatin reduces human alpha-Synuclein processing, aggregation and synaptic impairment in [A30P]αSyn transgenic mice.

    Science.gov (United States)

    Diepenbroek, Meike; Casadei, Nicolas; Esmer, Hakan; Saido, Takaomi C; Takano, Jiro; Kahle, Philipp J; Nixon, Ralph A; Rao, Mala V; Melki, Ronald; Pieri, Laura; Helling, Stefan; Marcus, Katrin; Krueger, Rejko; Masliah, Eliezer; Riess, Olaf; Nuber, Silke

    2014-08-01

    Lewy bodies, a pathological hallmark of Parkinson's disease (PD), contain aggregated alpha-synuclein (αSyn), which is found in several modified forms and can be discovered phosphorylated, ubiquitinated and truncated. Aggregation-prone truncated species of αSyn caused by aberrant cleavage of this fibrillogenic protein are hypothesized to participate in its sequestration into inclusions subsequently leading to synaptic dysfunction and neuronal death. Here, we investigated the role of calpain cleavage of αSyn in vivo by generating two opposing mouse models. We crossed into human [A30P]αSyn transgenic (i) mice deficient for calpastatin, a calpain-specific inhibitor, thus enhancing calpain activity (SynCAST(-)) and (ii) mice overexpressing human calpastatin leading to reduced calpain activity (SynCAST(+)). As anticipated, a reduced calpain activity led to a decreased number of αSyn-positive aggregates, whereas loss of calpastatin led to increased truncation of αSyn in SynCAST(-). Furthermore, overexpression of calpastatin decreased astrogliosis and the calpain-dependent degradation of synaptic proteins, potentially ameliorating the observed neuropathology in [A30P]αSyn and SynCAST(+) mice. Overall, our data further support a crucial role of calpains, particularly of calpain 1, in the pathogenesis of PD and in disease-associated aggregation of αSyn, indicating a therapeutic potential of calpain inhibition in PD. PMID:24619358

  6. The Role of Catalase in Pulmonary Fibrosis

    Directory of Open Access Journals (Sweden)

    Takigawa Tomoko

    2010-12-01

    Full Text Available Abstract Background Catalase is preferentially expressed in bronchiolar and alveolar epithelial cells, and acts as an endogenous antioxidant enzyme in normal lungs. We thus postulated epithelial damage would be associated with a functional deficiency of catalase during the development of lung fibrosis. Methods The present study evaluates the expression of catalase mRNA and protein in human interstitial pneumonias and in mouse bleomycin-induced lung injury. We examined the degree of bleomycin-induced inflammation and fibrosis in the mice with lowered catalase activity. Results In humans, catalase was decreased at the levels of activity, protein content and mRNA expression in fibrotic lungs (n = 12 compared to control lungs (n = 10. Immunohistochemistry revealed a decrease in catalase in bronchiolar epithelium and abnormal re-epithelialization in fibrotic areas. In C57BL/6J mice, catalase activity was suppressed along with downregulation of catalase mRNA in whole lung homogenates after bleomycin administration. In acatalasemic mice, neutrophilic inflammation was prolonged until 14 days, and there was a higher degree of lung fibrosis in association with a higher level of transforming growth factor-β expression and total collagen content following bleomycin treatment compared to wild-type mice. Conclusions Taken together, these findings demonstrate diminished catalase expression and activity in human pulmonary fibrosis and suggest the protective role of catalase against bleomycin-induced inflammation and subsequent fibrosis.

  7. Response of soil catalase activity to chromium contamination

    Institute of Scientific and Technical Information of China (English)

    Zofia St(e)pniewska; Agnieszka Woli(n)ska; Joanna Ziomek

    2009-01-01

    The impact of chromium (III) and (VI) forms on soil catalase activity is presented.The Orthic Podzol, Haplic Phaeozem and Mollic Gleysol from different depths were used in the experiment.The soil samples were amended with solution of Cr(III) using CrCl3, and with Cr(VI) using K2Cr2O7 in the concentration range from 0 to 20 mg/kg, whereas the samples without the addition of chromium served as control.Catalase activity was assayed by one of the commonly used spectrophotometric methods.As it is demonstrated in the experiment, both Cr(III) and Cr(VI) forms have ability to reduce soil catalase activity.A chromium dose of 20 mg/kg caused the inhibition of catalase activity and the corresponding contamination levels ranged from 75% to 92% for Cr(III) and 68% to 76% for Cr(VI), with relation to the control.Catalase activity reached maximum in the soil material from surface layers (0-25 cm), typically characterized by the highest content of organic matter creating favorable conditions for microorganisms.

  8. Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture

    Energy Technology Data Exchange (ETDEWEB)

    Miller-Pinsler, Lutfiya [Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Wells, Peter G., E-mail: pg.wells@utoronto.ca [Division of Biomolecular Sciences, Faculty of Pharmacy, University of Toronto, Toronto, Ontario (Canada); Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada)

    2015-09-15

    Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Cat{sup b}/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1), exposed for 24 h to 2 or 4 mg/mL EtOH or vehicle, and evaluated for functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p < 0.001). Maternal pretreatment of C57BL/6 WT dams with 50 kU/kg PEG-catalase (PEG-cat) 8 h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p < 0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p < 0.01), and trends for reduced anterior neuropore closure, turning and crown–rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p < 0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. - Highlights: • Ethanol (EtOH) exposure causes structural embryopathies in embryo culture. • Genetically enhanced catalase (hCat) protects against EtOH embryopathies. • Genetically deficient catalase (aCat) exacerbates EtOH embryopathies. • Embryonic catalase is developmentally important. • Et

  9. Embryonic catalase protects against ethanol embryopathies in acatalasemic mice and transgenic human catalase-expressing mice in embryo culture

    International Nuclear Information System (INIS)

    Reactive oxygen species (ROS) have been implicated in the mechanism of ethanol (EtOH) teratogenicity, but the protective role of the embryonic antioxidative enzyme catalase is unclear, as embryonic activity is only about 5% of maternal levels. We addressed this question in a whole embryo culture model. C57BL/6 mouse embryos expressing human catalase (hCat) or their wild-type (C57BL/6 WT) controls, and C3Ga.Cg-Catb/J catalase-deficient, acatalasemic (aCat) mouse embryos or their wild-type C3HeB/FeJ (C3H WT) controls, were explanted on gestational day (GD) 9 (plug = GD 1), exposed for 24 h to 2 or 4 mg/mL EtOH or vehicle, and evaluated for functional and morphological changes. hCat and C57BL/6 WT vehicle-exposed embryos developed normally, while EtOH was embryopathic in C57BL/6 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed, turning and head length, whereas hCat embryos were protected (p < 0.001). Maternal pretreatment of C57BL/6 WT dams with 50 kU/kg PEG-catalase (PEG-cat) 8 h prior to embryo culture, which increases embryonic catalase activity, blocked all EtOH embryopathies (p < 0.001). Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to WT controls, suggesting that endogenous ROS are embryopathic. EtOH was more embryopathic in aCat embryos than WT controls, evidenced by reduced head length and somite development (p < 0.01), and trends for reduced anterior neuropore closure, turning and crown–rump length. Maternal pretreatment of aCat dams with PEG-Cat blocked all EtOH embryopathies (p < 0.05). These data suggest that embryonic catalase is a determinant of risk for EtOH embryopathies. - Highlights: • Ethanol (EtOH) exposure causes structural embryopathies in embryo culture. • Genetically enhanced catalase (hCat) protects against EtOH embryopathies. • Genetically deficient catalase (aCat) exacerbates EtOH embryopathies. • Embryonic catalase is developmentally important. • EtOH developmental

  10. Overexpression of a maize SNF-related protein kinase gene, ZmSnRK2.11, reduces salt and drought tolerance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; CHEN Xun-ji; WANG Jian-hua; ZHENG Jun

    2015-01-01

    Sucrose non-fermenting-1 related protein kinase 2 (SnRK2) is a unique family of protein kinases associated with abiotic stress signal transduction in plants. In this study, a maize SnRK2 gene ZmSnRK2.11 was cloned and characterized. The results showed that ZmSnRK2.11 is up-regulated by high-salinity and dehydration treatment, and it is expressed mainly in maize mature leaf. A transient expression assay using onion epidermal cel s revealed that ZmSnRK2.11-GFP fusion proteins are localized to both the nucleus and cytoplasm. Overexpressing-ZmSnRK2.11 in Arabidopsis resulted in salt and drought sensitivity phenotypes that exhibited an increased rate of water loss, reduced relative water content, delayed stoma closure, accumulated less free proline content and increased malondialdehyde (MDA) content relative to the phenotypes observed in wild-type (WT) control. Furthermore, overexpression of ZmSnRK2.11 up-regulated the expression of the genes ABI1 and ABI2 and decreased the expression of DREB2A and P5CS1. Taken together, our results suggest that ZmSnRK2.11 is a possible negative regulator involved in the salt and drought stress signal transduction pathways in plants.

  11. SK2 potassium channel over-expression in basolateral amygdala reduces anxiety, stress-induced corticosterone and dendritic arborization

    OpenAIRE

    R. Mitra; Ferguson, D.; Sapolsky, RM

    2009-01-01

    The basolateral amygdala is critical for generation of anxiety. Additionally, exposure to both stress and glucocorticoids induce anxiety. Demonstrated ability of the amygdala to change in response to stress and glucocorticoids could thus be important therapeutic target for anxiety management. Several studies have reported a relationship between anxiety and dendritic arborization of the amygdaloid neurons. In this study we employed a gene therapeutic approach to reduce anxiety and dendritic ar...

  12. Overexpression of SpCBL6, a calcineurin B-like protein of Stipa purpurea, enhanced cold tolerance and reduced drought tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Zhou, Yanli; Cheng, Ying; Yang, Yunqiang; Li, Xiong; Supriyo, Basak; Sun, Xudong; Yang, Yongping

    2016-09-01

    The purpose of the present study was to characterize SpCBL6 (GenBank accession number: KT780442) from Stipa purpurea and elucidate the function of this protein in abiotic stress. The full-length cDNA of SpCBL6 was isolated from S. purpurea by rapid amplification of cDNA ends methods. Laser confocal microscopy was used to analyze the subcellular localization of SpCBL6. The constructs of 35S:GFP-SpCBL6 was used to transform wild-type (WT) Arabidopsis plants (ecotype Columbia-0) with the floral dip method. Quantitative reverse-transcription PCR (qRT-PCR), water potential, photosynthetic efficiency (F v/F m), and ion leakage was performed to investigate the role of SpCBL6 in abiotic stress. The open reading frame of SpCBL6 contains 681 bp nucleotides and encodes a 227-amino acid polypeptide. Phylogenetic analysis indicated that SpCBL6 showed the highest similarity with rice OsCBL6. SpCBL6 transcripts were induced by freezing and drought treatments. Subcellular localization analysis showed that SpCBL6 was located in membrane of protoplast. Overexpression of SpCBL6 in Arabidopsis thaliana demonstrated that the transgenic plants were more tolerant to cold treatment, but less tolerant to drought, compared with the plants. qRT-PCR analysis showed that the drought stress marker genes were inhibited in transgenic plants, whereas the cold stress marker genes were enhanced. Further analysis showed that SpCBL6-overexpressing plants showed enhanced water potential, photosynthetic efficiency (F v/F m), and reduced ion leakage compared with the wild-type after cold treatment. Collectively, these results indicate that SpCBL6, a new member of the CBL gene family isolated from S. purpurea, enhances cold tolerance and reduces drought tolerance in plants. PMID:27393148

  13. Transient overexpression of DNA adenine methylase enables efficient and mobile genome engineering with reduced off-target effects

    DEFF Research Database (Denmark)

    Lennen, Rebecca; Nilsson Wallin, Annika; Pedersen, Margit;

    2016-01-01

    Homologous recombination of single-stranded oligonucleotides is a highly efficient process for introducing precise mutations into the genome of E. coli and other organisms when mismatch repair (MMR) is disabled. This can result in the rapid accumulation of off-target mutations that can mask desired...... result in reduced efficiencies of replacement. Therefore a new system was developed, Transient Mutator Multiplex Automated Genome Engineering (TM-MAGE), that solves problems encountered in other methods for oligonucleotide-mediated recombination. TM-MAGE enables nearly equivalent efficiencies of allelic...

  14. Transient overexpression of DNA adenine methylase enables efficient and mobile genome engineering with reduced off-target effects.

    Science.gov (United States)

    Lennen, Rebecca M; Nilsson Wallin, Annika I; Pedersen, Margit; Bonde, Mads; Luo, Hao; Herrgård, Markus J; Sommer, Morten O A

    2016-02-29

    Homologous recombination of single-stranded oligonucleotides is a highly efficient process for introducing precise mutations into the genome of E. coli and other organisms when mismatch repair (MMR) is disabled. This can result in the rapid accumulation of off-target mutations that can mask desired phenotypes, especially when selections need to be employed following the generation of combinatorial libraries. While the use of inducible mutator phenotypes or other MMR evasion tactics have proven useful, reported methods either require non-mobile genetic modifications or costly oligonucleotides that also result in reduced efficiencies of replacement. Therefore a new system was developed, Transient Mutator Multiplex Automated Genome Engineering (TM-MAGE), that solves problems encountered in other methods for oligonucleotide-mediated recombination. TM-MAGE enables nearly equivalent efficiencies of allelic replacement to the use of strains with fully disabled MMR and with an approximately 12- to 33-fold lower off-target mutation rate. Furthermore, growth temperatures are not restricted and a version of the plasmid can be readily removed by sucrose counterselection. TM-MAGE was used to combinatorially reconstruct mutations found in evolved salt-tolerant strains, enabling the identification of causative mutations and isolation of strains with up to 75% increases in growth rate and greatly reduced lag times in 0.6 M NaCl. PMID:26496947

  15. Long-term controlled GDNF over-expression reduces dopamine transporter activity without affecting tyrosine hydroxylase expression in the rat mesostriatal system.

    Science.gov (United States)

    Barroso-Chinea, Pedro; Cruz-Muros, Ignacio; Afonso-Oramas, Domingo; Castro-Hernández, Javier; Salas-Hernández, Josmar; Chtarto, Abdelwahed; Luis-Ravelo, Diego; Humbert-Claude, Marie; Tenenbaum, Liliane; González-Hernández, Tomás

    2016-04-01

    The dopamine (DA) transporter (DAT) is a plasma membrane glycoprotein expressed in dopaminergic (DA-) cells that takes back DA into presynaptic neurons after its release. DAT dysfunction has been involved in different neuro-psychiatric disorders including Parkinson's disease (PD). On the other hand, numerous studies support that the glial cell line-derived neurotrophic factor (GDNF) has a protective effect on DA-cells. However, studies in rodents show that prolonged GDNF over-expression may cause a tyrosine hydroxylase (TH, the limiting enzyme in DA synthesis) decline. The evidence of TH down-regulation suggests that another player in DA handling, DAT, may also be regulated by prolonged GDNF over-expression, and the possibility that this effect is induced at GDNF expression levels lower than those inducing TH down-regulation. This issue was investigated here using intrastriatal injections of a tetracycline-inducible adeno-associated viral vector expressing human GDNF cDNA (AAV-tetON-GDNF) in rats, and doxycycline (DOX; 0.01, 0.03, 0.5 and 3mg/ml) in the drinking water during 5weeks. We found that 3mg/ml DOX promotes an increase in striatal GDNF expression of 12× basal GDNF levels and both DA uptake decrease and TH down-regulation in its native and Ser40 phosphorylated forms. However, 0.5mg/ml DOX promotes a GDNF expression increase of 3× basal GDNF levels with DA uptake decrease but not TH down-regulation. The use of western-blot under non-reducing conditions, co-immunoprecipitation and in situ proximity ligation assay revealed that the DA uptake decrease is associated with the formation of DAT dimers and an increase in DAT-α-synuclein interactions, without changes in total DAT levels or its compartmental distribution. In conclusion, at appropriate GDNF transduction levels, DA uptake is regulated through DAT protein-protein interactions without interfering with DA synthesis. PMID:26777664

  16. Overexpression of SrUGT85C2 from Stevia reduced growth and yield of transgenic Arabidopsis by influencing plastidial MEP pathway.

    Science.gov (United States)

    Guleria, Praveen; Masand, Shikha; Yadav, Sudesh Kumar

    2014-04-15

    The transcript expression of a gene SrUGT85C2 has been documented for direct relation with steviol glycoside content in Stevia plant. Steviol glycoside and gibberellin biosynthetic routes are divergent branches of methyl erythritol-4 phosphate (MEP) pathway. So, SrUGT85C2 might be an influencing gibberellin content. Hence in the present study, transgenic Arabidopsis thaliana overexpressing SrUGT85C2 cDNA from Stevia rebaudiana was developed to check its effect on gibberellin accumulation and related plant growth parameters. The developed transgenics showed a noteworthy decrease of 78-83% in GA3 content. Moreover, the transgenics showed a gibberellin deficient phenotype comprising stunted hypocotyl length, reduced shoot growth and a significant fall in relative water content. Transgenics also showed 17-37 and 64-76% reduction in chlorophyll a and chlorophyll b contents, respectively. Reduction in photosynthetic pigments could be responsible for the noticed significant decrease in plant biomass. Like steviol glycoside and gibberellin biosynthesis, chlorophyll biosynthesis also occurs from the precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) of MEP pathway in the plastids. The observed downregulated expression of genes encoding MEP pathway enzymes geranyl geranyl diphosphate synthase (GGDPS), copalyl diphosphate synthase (CDPS), kaurenoic acid oxidase (KAO), chlorophyll synthetase and chlorophyll a oxygenase in transgenics overexpressing SrUGT85C2 might be responsible for the reduction in gibberellins as well as chlorophyll. This study has documented for the first time the regulatory role of SrUGT85C2 in the biosynthesis of steviol glycoside, gibberellins and chlorophyll. PMID:24518812

  17. Fungal catalases: function, phylogenetic origin and structure.

    Science.gov (United States)

    Hansberg, Wilhelm; Salas-Lizana, Rodolfo; Domínguez, Laura

    2012-09-15

    Most fungi have several monofunctional heme-catalases. Filamentous ascomycetes (Pezizomycotina) have two types of large-size subunit catalases (L1 and L2). L2-type are usually induced by different stressors and are extracellular enzymes; those from the L1-type are not inducible and accumulate in asexual spores. L2 catalases are important for growth and the start of cell differentiation, while L1 are required for spore germination. In addition, pezizomycetes have one to four small-size subunit catalases. Yeasts (Saccharomycotina) do not have large-subunit catalases and generally have one peroxisomal and one cytosolic small-subunit catalase. Small-subunit catalases are inhibited by substrate while large-subunit catalases are activated by H(2)O(2). Some small-subunit catalases bind NADPH preventing inhibition by substrate. We present a phylogenetic analysis revealing one or two events of horizontal gene transfers from Actinobacteria to a fungal ancestor before fungal diversification, as the origin of large-size subunit catalases. Other possible horizontal transfers of small- and large-subunit catalases genes were detected and one from bacteria to the fungus Malassezia globosa was analyzed in detail. All L2-type catalases analyzed presented a secretion signal peptide. Mucorales preserved only L2-type catalases, with one containing a secretion signal if two or more are present. Basidiomycetes have only L1-type catalases, all lacking signal peptide. Fungal small-size catalases are related to animal catalases and probably evolved from a common ancestor. However, there are several groups of small-size catalases. In particular, a conserved group of fungal sequences resemble plant catalases, whose phylogenetic origin was traced to a group of bacteria. This group probably has the heme orientation of plant catalases and could in principle bind NADPH. From almost a hundred small-subunit catalases only one fourth has a peroxisomal localization signal and in fact many fungi lack

  18. Studies on the catalase of Histoplasma capsulatum.

    OpenAIRE

    Howard, D H

    1983-01-01

    Factors which control the levels of catalase within yeast cells of Histoplasma capsulatum were studied. Only a small fraction of the total catalase activity could be detected in whole cells. The bulk of the activity was revealed in cell-free extracts or in cells permeabilized with acetone. The formation of the enzyme was regulated by glucose and by oxygen. There were large, consistent differences in the levels of catalase among strains of H. capsulatum. The sensitivity of the strains to H2O2 ...

  19. Evolution of catalase activity during nystatin biosynthesis

    Directory of Open Access Journals (Sweden)

    Cristina Bota

    2009-03-01

    Full Text Available The research studies focused on the dynamics of catalase during nystatin biosynthesis by Streptomyces noursei. The catalase activity was determined by growing a pure culture of Streptomyces noursei from the strain collection owned by the company S.C. Antibiotice Iasi on biosynthesis medium. The test was performed on two experimental models of biosynthesis, one using sunflower oil, while the other soybean oil as basic nutrients. Special attention was paid to the connection between the evolution of the biomass and the level of catalase activity.

  20. Melanocortin 1 receptor agonist protects podocytes through catalase and RhoA activation.

    Science.gov (United States)

    Elvin, Johannes; Buvall, Lisa; Lindskog Jonsson, Annika; Granqvist, Anna; Lassén, Emelie; Bergwall, Lovisa; Nyström, Jenny; Haraldsson, Börje

    2016-05-01

    Drugs containing adrenocorticotropic hormone have been used as therapy for patients with nephrotic syndrome. We have previously shown that adrenocorticotropic hormone and a selective agonist for the melanocortin 1 receptor (MC1R) exert beneficial actions in experimental membranous nephropathy with reduced proteinuria, reduced oxidative stress, and improved glomerular morphology and function. Our hypothesis is that MC1R activation in podocytes elicits beneficial effects by promoting stress fibers and maintaining podocyte viability. To test the hypothesis, we cultured podocytes and used highly specific agonists for MC1R. Podocytes were subjected to the nephrotic-inducing agent puromycin aminonucleoside, and downstream effects of MC1R activation on podocyte survival, antioxidant defense, and cytoskeleton dynamics were studied. To increase the response and enhance intracellular signals, podocytes were transduced to overexpress MC1R. We showed that puromycin promotes MC1R expression in podocytes and that activation of MC1R promotes an increase of catalase activity and reduces oxidative stress, which results in the dephosphorylation of p190RhoGAP and formation of stress fibers through RhoA. In addition, MC1R agonists protect against apoptosis. Together, these mechanisms protect the podocyte against puromycin. Our findings strongly support the hypothesis that selective MC1R-activating agonists protect podocytes and may therefore be useful to treat patients with nephrotic syndromes commonly considered as podocytopathies. PMID:26887829

  1. Catalase protects HepG2 cells from apoptosis induced by DNA-damaging agents by accelerating the degradation of p53.

    Science.gov (United States)

    Bai, Jingxiang; Cederbaum, Arthur I

    2003-02-14

    Oxidants such as H(2)O(2) play a role in the toxicity of certain DNA-damaging agents, a process that often involves the tumor suppressor p53. H(2)O(2) is rapidly degraded by catalase, which protects cells against oxidant injury. To study the effect of catalase on apoptosis induced by DNA-damaging agents, HepG2 cells were infected with adenovirus containing the cDNA of catalase (Ad-Cat). Forty-eight hours after infection, catalase protein and activity was increased 7-10-fold compared with control cells infected with Ad-LacZ. After treatment with Vp16 or mitomycin C, control cells underwent apoptosis in a p53-dependent manner; however, overexpression of catalase inhibited this apoptosis. Basal levels as well as Vp16- or mitomycin C-stimulated levels of p53 and p21 protein were decreased in the catalase-overexpressing cells as compared with control cells; however, p53 mRNA levels were not decreased by catalase. There was no difference in p53 protein synthesis between catalase-overexpressing cells and control cells. However, pulse-chase experiments indicated that p53 protein degradation was enhanced in the catalase-overexpressing cells. Proteasome inhibitors but not calpeptin prevented the catalase-mediated decrease of p53 content. Whereas Vp16 increased, catalase overexpression decreased the phosphorylation of p53. The protein phosphatase inhibitor okadaic acid did not prevent the catalase-mediated down-regulation of p53 or phosphorylated p53. These results demonstrate that catalase protects HepG2 cells from apoptosis induced by DNA-damaging agents in association with decreasing p53 phosphorylation; the latter may lead to an acceleration in the degradation of p53 protein by the proteasome complex. This suggests that the level of catalase may play a critical role in cell-induced resistance to the effects of anti-cancer drugs which up-regulate p53. PMID:12468545

  2. Cardiac-Restricted IGF-1Ea Overexpression Reduces the Early Accumulation of Inflammatory Myeloid Cells and Mediates Expression of Extracellular Matrix Remodelling Genes after Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Enrique Gallego-Colon

    2015-01-01

    Full Text Available Strategies to limit damage and improve repair after myocardial infarct remain a major therapeutic goal in cardiology. Our previous studies have shown that constitutive expression of a locally acting insulin-like growth factor-1 Ea (IGF-1Ea propeptide promotes functional restoration after cardiac injury associated with decreased scar formation. In the current study, we investigated the underlying molecular and cellular mechanisms behind the enhanced functional recovery. We observed improved cardiac function in mice overexpressing cardiac-specific IGF-1Ea as early as day 7 after myocardial infarction. Analysis of gene transcription revealed that supplemental IGF-1Ea regulated expression of key metalloproteinases (MMP-2 and MMP-9, their inhibitors (TIMP-1 and TIMP-2, and collagen types (Col 1α1 and Col 1α3 in the first week after injury. Infiltration of inflammatory cells, which direct the remodelling process, was also altered; in particular there was a notable reduction in inflammatory Ly6C+ monocytes at day 3 and an increase in anti-inflammatory CD206+ macrophages at day 7. Taken together, these results indicate that the IGF-1Ea transgene shifts the balance of innate immune cell populations early after infarction, favouring a reduction in inflammatory myeloid cells. This correlates with reduced extracellular matrix remodelling and changes in collagen composition that may confer enhanced scar elasticity and improved cardiac function.

  3. Overexpression of Rice Glutaredoxin OsGrx_C7 and OsGrx_C2.1 Reduces Intracellular Arsenic Accumulation and Increases Tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Verma, Pankaj K; Verma, Shikha; Pande, Veena; Mallick, Shekhar; Deo Tripathi, Rudra; Dhankher, Om P; Chakrabarty, Debasis

    2016-01-01

    Glutaredoxins (Grxs) are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice), the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As) tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops. PMID:27313586

  4. Overexpression of rice glutaredoxin OsGrx_C7 and OsGrx_C2.1 reduces intracellular arsenic accumulation and increases tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Verma

    2016-06-01

    Full Text Available Glutaredoxins (Grxs are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice, the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops.

  5. Overexpression of the Brassica rapa transcription factor WRKY12 results in reduced soft rot symptoms caused by Pectobacterium carotovorum in Arabidopsis and Chinese cabbage.

    Science.gov (United States)

    Kim, H S; Park, Y H; Nam, H; Lee, Y M; Song, K; Choi, C; Ahn, I; Park, S R; Lee, Y H; Hwang, D J

    2014-09-01

    Chinese cabbage (Brassica rapa L. ssp. pekinensis), an important vegetable crop, can succumb to diseases such as bacterial soft rot, resulting in significant loss of crop productivity and quality. Pectobacterium carotovorum ssp. carotovorum (Pcc) causes soft rot disease in various plants, including Chinese cabbage. To overcome crop loss caused by bacterial soft rot, a gene from Chinese cabbage was isolated and characterised in this study. We isolated the BrWRKY12 gene from Chinese cabbage, which is a group II member of the WRKY transcription factor superfamily. The 645-bp coding sequence of BrWRKY12 translates to a protein with a molecular mass of approximately 24.4 kDa, and BrWRKY12 was exclusively localised in the nucleus. Transcripts of BrWRKY12 were induced by Pcc infection in Brassica. Heterologous expression of BrWRKY12 resulted in reduced susceptibility to Pcc but not to Pseudomonas syringae pv. tomato in Arabidopsis. Defence-associated genes, such as AtPDF1.2 and AtPGIP2, were constitutively expressed in transgenic lines overexpressing BrWRKY12. The expression of AtWKRY12, which is the closest orthologue of BrWRKY12, was down-regulated by Pcc in Arabidopsis. However, the Atwrky12-2 mutants did not show any difference in response to Pcc, pointing to a difference in function of WRKY12 in Brassica and Arabidopsis. Furthermore, BrWRKY12 in Chinese cabbage also exhibited enhanced resistance to bacterial soft rot and increased the expression of defence-associated genes. In summary, BrWRKY12 confers enhanced resistance to Pcc through transcriptional activation of defence-related genes. PMID:24552622

  6. Multidrug resistance-associated protein gene overexpression and reduced drug sensitivity of topoisomerase II in a human breast carcinoma MCF7 cell line selected for etoposide resistance.

    Science.gov (United States)

    Schneider, E; Horton, J K; Yang, C H; Nakagawa, M; Cowan, K H

    1994-01-01

    A human breast cancer cell line (MCF7/WT) was selected for resistance to etoposide (VP-16) by stepwise exposure to 2-fold increasing concentrations of this agent. The resulting cell line (MCF7/VP) was 28-, 21-, and 9-fold resistant to VP-16, VM-26, and doxorubicin, respectively. MCF7/VP cells also exhibited low-level cross-resistance to 4'-(9-acridinylamino)-methanesulfon-m-anisidide, mitoxantrone, and vincristine and no cross-resistance to genistein and camptothecin. Furthermore, these cells were collaterally sensitive to the alkylating agents melphalan and chlorambucil. DNA topoisomerase II levels were similar in both wild-type MCF7/WT and drug-resistant MCF7/VP cells. In contrast, topoisomerase II from MCF7/VP cells appeared to be 7-fold less sensitive to drug-induced cleavable complex formation in whole cells and 3-fold less sensitive in nuclear extracts than topoisomerase II from MCF7/WT cells. Although this suggested that the resistant cells may contain a qualitatively altered topoisomerase II, no mutations were detected in either the ATP-binding nor the putative breakage/resealing regions of either DNA topoisomerase II alpha or II beta. In addition, the steady-state intracellular VP-16 concentration was reduced by 2-fold in the resistant cells, in the absence of detectable mdr1/P-gp expression and without any change in drug efflux. In contrast, expression of the gene encoding the MRP was increased at least 10-fold in resistant MCF7/VP cells as compared to sensitive MCF7/WT cells. These results suggest that resistance to epipodophyllotoxins in MCF7/VP cells is multifactorial, involving a reduction in intracellular drug concentration, possibly as a consequence of MRP overexpression, and an altered DNA topoisomerase II drug sensitivity. PMID:7903202

  7. Progeric effects of catalase inactivation in human cells

    International Nuclear Information System (INIS)

    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

  8. Potential enzyme toxicity of oxytetracycline to catalase

    Energy Technology Data Exchange (ETDEWEB)

    Chi Zhenxing; Liu Rutao; Zhang Hao, E-mail: Trutaoliu@sdu.edu.cn [School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment and Health, Shandong Province, 27 Shanda South Road, Jinan 250100 (China)

    2010-10-15

    Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K{sub 293K} = 7.09 x 10{sup 4} L mol{sup -1} and K{sub 311K} = 3.31 x 10{sup 4} L mol{sup -1}. The thermodynamic parameters ({Delta}H{sup o}, {Delta}G{sup o} and {Delta}S{sup o}) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

  9. Comparative study on the catalase activity in grassy and forestry plants exposed to low gamma radiation

    International Nuclear Information System (INIS)

    Since gamma rays level in atmosphere occasionally increases affecting biosphere,the radiation effect damages seriously certain plant species. This study was focused on a grassy species,Triticum aestivum, in comparison to a forestry species, namely Quercus robur. Young plantlets were exposed to weak gamma rays delivered by a laboratory 60 Co source, for different irradiation times. The enzymatic activity of catalase was evaluated using biochemical methods. Triticum aestivum presented a slight enhancing of catalase, both in caryopsides and leafs. Quercus robur revealed a rapid linear enhancing of catalase in saplings cultivated in laboratory while saplings grown in forestry were characterized by a reduced catalase activity. Concurrent phenomena of enzyme biosynthesis stimulation and enzyme structure damage are presumed to be the cause of such behavior. (authors)

  10. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    Directory of Open Access Journals (Sweden)

    Klingelhoeffer Christoph

    2012-05-01

    Full Text Available Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L. The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods Effective concentration (EC50 values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50 > 20 mmol/L and fifty-five percent had an EC50 50 of 2.6–5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L, was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L. Conclusions Fifty-five percent of the human cancer cell lines tested were unable to protect themselves

  11. 21 CFR 184.1034 - Catalase (bovine liver).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Catalase (bovine liver). 184.1034 Section 184.1034... Listing of Specific Substances Affirmed as GRAS § 184.1034 Catalase (bovine liver). (a) Catalase (bovine liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It...

  12. Targeted Expression of Catalase to Mitochondria Protects Against Ischemic Myopathy in High-Fat Diet-Fed Mice.

    Science.gov (United States)

    Ryan, Terence E; Schmidt, Cameron A; Green, Thomas D; Spangenburg, Espen E; Neufer, P Darrell; McClung, Joseph M

    2016-09-01

    Patients with type 2 diabetes respond poorly to treatments for peripheral arterial disease (PAD) and are more likely to present with the most severe manifestation of the disease, critical limb ischemia. The underlying mechanisms linking type 2 diabetes and the severity of PAD manifestation are not well understood. We sought to test whether diet-induced mitochondrial dysfunction and oxidative stress would increase the susceptibility of the peripheral limb to hindlimb ischemia (HLI). Six weeks of high-fat diet (HFD) in C57BL/6 mice was insufficient to alter skeletal muscle mitochondrial content and respiratory function or the size of ischemic lesion after HLI, despite reducing blood flow. However, 16 weeks of HFD similarly decreased ischemic limb blood flow, but also exacerbated limb tissue necrosis, increased the myopathic lesion size, reduced muscle regeneration, attenuated muscle function, and exacerbated ischemic mitochondrial dysfunction. Mechanistically, mitochondrial-targeted overexpression of catalase prevented the HFD-induced ischemic limb necrosis, myopathy, and mitochondrial dysfunction, despite no improvement in limb blood flow. These findings demonstrate that skeletal muscle mitochondria are a critical pathological link between type 2 diabetes and PAD. Furthermore, therapeutically targeting mitochondria and oxidant burden is an effective strategy to alleviate tissue loss and ischemic myopathy during PAD. PMID:27284110

  13. Catalase and NO CATALASE ACTIVITY1 promote autophagy-dependent cell death in Arabidopsis

    DEFF Research Database (Denmark)

    Hackenberg, Thomas; Andersen, Trine Juul; Auzina, Aija;

    2013-01-01

    Programmed cell death often depends on generation of reactive oxygen species, which can be detoxified by antioxidative enzymes, including catalases. We previously isolated catalase-deficient mutants (cat2) in a screen for resistance to hydroxyurea-induced cell death. Here, we identify an Arabidop......Programmed cell death often depends on generation of reactive oxygen species, which can be detoxified by antioxidative enzymes, including catalases. We previously isolated catalase-deficient mutants (cat2) in a screen for resistance to hydroxyurea-induced cell death. Here, we identify an......-induced autophagy appeared normal in the nca1 and cat2 mutants. By contrast, autophagic degradation induced by avrRpm1 challenge was compromised, indicating that catalase acted upstream of immunity-triggered autophagy. The direct interaction of catalase with reactive oxygen species could allow catalase to act as a...

  14. Reduction of hydrogen peroxide accumulation and toxicity by a catalase from Mycoplasma iowae.

    Directory of Open Access Journals (Sweden)

    Rachel E Pritchard

    Full Text Available 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.

  15. Reduction of hydrogen peroxide accumulation and toxicity by a catalase from Mycoplasma iowae.

    Science.gov (United States)

    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

  16. Molecular Characterization of a Catalase from Hydra vulgaris

    Science.gov (United States)

    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

  17. Arylsulfatase A Overexpressing Human iPSC-derived Neural Cells Reduce CNS Sulfatide Storage in a Mouse Model of Metachromatic Leukodystrophy.

    Science.gov (United States)

    Doerr, Jonas; Böckenhoff, Annika; Ewald, Benjamin; Ladewig, Julia; Eckhardt, Matthias; Gieselmann, Volkmar; Matzner, Ulrich; Brüstle, Oliver; Koch, Philipp

    2015-09-01

    Metachromatic leukodystrophy (MLD) is an inherited lysosomal storage disorder resulting from a functional deficiency of arylsulfatase A (ARSA), an enzyme that catalyzes desulfation of 3-O-sulfogalactosylceramide (sulfatide). Lack of active ARSA leads to the accumulation of sulfatide in oligodendrocytes, Schwann cells and some neurons and triggers progressive demyelination, the neuropathological hallmark of MLD. Several therapeutic approaches have been explored, including enzyme replacement, autologous hematopoietic stem cell-based gene therapy, intracerebral gene therapy or cell-based gene delivery into the central nervous system (CNS). However, long-term treatment of the blood-brain-barrier protected CNS remains challenging. Here we used MLD patient-derived induced pluripotent stem cells (iPSCs) to generate long-term self-renewing neuroepithelial stem cells and astroglial progenitors for cell-based ARSA replacement. Following transplantation of ARSA-overexpressing precursors into ARSA-deficient mice we observed a significant reduction of sulfatide storage up to a distance of 300 µm from grafted cells. Our data indicate that neural precursors generated via reprogramming from MLD patients can be engineered to ameliorate sulfatide accumulation and may thus serve as autologous cell-based vehicle for continuous ARSA supply in MLD-affected brain tissue. PMID:26061647

  18. Determination of catalase, peroxidase, and superoxide dismutase within the genus Legionella.

    OpenAIRE

    Pine, L; Hoffman, P S; Malcolm, G B; Benson, R F; Keen, M G

    1984-01-01

    We examined 40 strains of Legionella for reduced-oxygen scavenging enzymes. Using a simple reaction chamber with a Swinney filter for the Beers and Sizer assay, we determined the catalase activity of live cells grown on buffered charcoal-yeast extract agar. For 29 strains of Legionella pneumophila, the apparent first-order rate constants for catalase ranged from 0.000 to 0.005. Similarly, low values ranging from 0.001 to 0.005 were observed for Legionella wadsworthii, Legionella oakridgensis,...

  19. Developmentally related responses of maize catalase genes to salicylic acid.

    OpenAIRE

    L. Guan; Scandalios, J G

    1995-01-01

    The response of the maize catalase genes (Cat1, Cat2, and Cat3) to salicylic acid (SA) was examined at two distinct developmental stages: embryogenesis and germination. A unique, germination-related differential response of each maize catalase gene to various doses of SA was observed. During late embryogenesis, total catalase activity in scutella increased dramatically with 1 mM SA treatment. The accumulation of Cat2 transcript and CAT-2 isozyme protein provided the major contribution to the ...

  20. Development of a new biosensor for determination of catalase activity.

    Science.gov (United States)

    Teke, Mustafa

    2014-01-01

    Catalase is one of the major antioxidant enzymes that catalyzes the hydrolysis of H2O2. The aim of this study was to suggest a new method for the assay of catalase activity. For this purpose, an amperometric biosensor based on glucose oxidase for determination of catalase activity was developed. Immobilization of glucose oxidase was made by a cross-linking method with glutaraldehyde on a Clark-type electrode (dissolved oxygen probe). Optimization and characterization properties of the biosensor were studied and determination of catalase activity in defined conditions was investigated in artificial serum solution. The results were compared with a reference method. PMID:24499365

  1. Relation of overexpression of S phase kinase-associated protein 2 with reduced expression of p27 and PTEN in human gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xiu-Mei Ma; Ying Liu; Jian-Wen Guo; Jiang-Hui Liu; Lian-Fu Zuo

    2005-01-01

    AIM: To investigate the significance of S phase kinaseassociated protein 2 (Skp2) expression in human gastric carcinoma and the relation between expressions of Skp2,p27 and PTEN.METHODS: Immunohistochemical analysis was performed on 138 gastric carcinoma specimens, their paired adjacent mucosa specimens, 102 paired lymphatic metastatic carcinoma tissue specimens, 30 dysplasia specimens, 30 intestinal metaplasia specimens, 10chronic superficial gastritis specimens and 5 normal gastric mucosa specimens for Skp2 expression and on 138 gastric carcinoma specimens for p27 and PTEN expression.RESULTS: Skp2 labeling frequency was significantly higher in intestinal metaplasia (12.68±0.86) and adjacent mucosa (19.32±1.22) than in normal gastric mucosa (0.53±0.13) and chronic superficial gastritis (0.47±0.19) (P = 0.000); in dysplasia (16.74±0.82) than in intestinal metaplasia (P = 0.000); in gastric primary carcinoma (31.34±2.17) than in dysplasia and adjacent mucosa (P = 0.000); in metastasis gastric carcinoma in lymph nodes (39.76±2.00) than in primary gastric carcinoma (P = 0.037), respectively. Skp2 labeling frequency was positively associated with differentiation degree (rho = 0.315, P = 0.000), vessel invasion (rho = 0.303, P = 0.000) and lymph node metastasis (rho = 0.254, P = 0.000) of gastric cancer. Expression of Skp2 was negatively associated with p27(rho = -0.451, P = 0.000) and PTEN (rho = -0.480,P = 0.000) expression in gastric carcinoma. p27 expression was positively associated with PTEN expression in gastric carcinoma (rho = 0.642, P = 0.000).CONCLUSION: Skp2 overexpression may be involved in carcinogenesis and progression of human gastric carcinoma in vivo, possibly via p27 proteolysis. PTEN may regulate the expression of p27 by negatively regulating Skp2 expression.

  2. High catalase production by Rhizobium radiobacter strain 2-1.

    Science.gov (United States)

    Nakayama, Mami; Nakajima-Kambe, Toshiaki; Katayama, Hideki; Higuchi, Kazuhiko; Kawasaki, Yoshio; Fuji, Ryujiro

    2008-12-01

    To promote the application of catalase for treating wastewater containing hydrogen peroxide, bacteria exhibiting high catalase activity were screened. A bacterium, designated strain 2-1, with high catalase activity was isolated from the wastewater of a beverage factory that uses hydrogen peroxide. Strain 2-1 was identified as Rhizobium radiobacter (formerly known as Agrobacterium tumefaciens) on the basis of both phenotypic and genotypic characterizations. Although some strains of R. radiobacter are known plant pathogens, polymerase chain reaction (PCR) analysis showed that strain 2-1 has no phytopathogenic factor. Compared with a type strain of R. radiobacter, the specific catalase activity of strain 2-1 was approximately 1000-fold. Moreover, Strain 2-1 grew faster and exhibited considerably higher catalase activity than other microorganisms that have been used for industrial catalase production. Strain 2-1 is harmless to humans and the environment and produces catalase efficiently, suggesting that strain 2-1 is a good resource for the mass production of catalase for the treatment of hydrogen peroxide-containing wastewater. PMID:19134550

  3. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Catalase derived from Micrococcus lysodeikticus... Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure culture... cheese, in accordance with the following conditions. (a) The organism Micrococcus lysodeikticus...

  4. Triclosan Can Select for an AdeIJK-Overexpressing Mutant of Acinetobacter baumannii ATCC 17978 That Displays Reduced Susceptibility to Multiple Antibiotics

    OpenAIRE

    Fernando, Dinesh M.; Xu, Wayne; Loewen, Peter C.; Zhanel, George G; Kumar, Ayush

    2014-01-01

    In order to determine if triclosan can select for mutants of Acinetobacter baumannii ATCC 17978 that display reduced susceptibilities to antibiotics, we isolated a triclosan-resistant mutant, A. baumannii AB042, by serial passaging of A. baumannii ATCC 17978 in growth medium supplemented with triclosan. The antimicrobial susceptibility of AB042 was analyzed by the 2-fold serial dilution method. Expression of five different resistance-nodulation-division (RND) pump-encoding genes (adeB, adeG, ...

  5. Isolation of the catalase T structural gene of Saccharomyces cerevisiae by functional complementation.

    OpenAIRE

    Spevak, W; Fessl, F; Rytka, J; Traczyk, A; Skoneczny, M; Ruis, H

    1983-01-01

    The catalase T structural gene of Saccharomyces cerevisiae was cloned by functional complementation of a mutation causing specific lack of the enzyme (cttl). Catalase T-deficient mutants were obtained by UV mutagenesis of an S. cerevisiae strain bearing the cas1 mutation, which causes insensitivity of catalase T to glucose repression. Since the second catalase protein of S. cerevisiae, catalase A, is completely repressed on 10% glucose, catalase T-deficient mutant colonies could be detected u...

  6. The Cryptococcus neoformans Catalase Gene Family and Its Role in Antioxidant Defense

    OpenAIRE

    Giles, Steven S.; Jason E. Stajich; Nichols, Connie; Gerrald, Quincy D.; Alspaugh, J. Andrew; Dietrich, Fred; Perfect, John R.

    2006-01-01

    In the present study, we sought to elucidate the contribution of the Cryptococcus neoformans catalase gene family to antioxidant defense. We employed bioinformatics techniques to identify four members of the C. neoformans catalase gene family and created mutants lacking single or multiple catalase genes. Based on a phylogenetic analysis, CAT1 and CAT3 encode putative spore-specific catalases, CAT2 encodes a putative peroxisomal catalase, and CAT4 encodes a putative cytosolic catalase. Only Ca...

  7. New evidence on the role of catalase in Escherichia coli-mediated biocorrosion

    International Nuclear Information System (INIS)

    Highlights: ► MIC on stainless by catalase deficient Escherichia coli bacteria reveals the enzyme influence. ► The localized damage was greater in the presence of the wild E. coli. ► Catalase assists oxygen generation by disproportionation of H2O2 to H2O and O2. - Abstract: The role of catalase on the microbiologically influenced corrosion mechanism by Escherichia coli (E. coli) has been examined, employing wild type and catalase-deficient cells. The bacteria were cultured for different times in the presence of AISI 316L stainless steel samples. The morphologies of the metallic surfaces covered by biofilms were studied by optical microscopy. The localized corrosion catalyzed by the bacteria was followed by scanning electron microscopy after immersion in the bacterial culture for different times. Susceptibility to corrosion was further investigated by potentiodynamic measurements. It was found that wild type E. coli is more aggressive than the mutant one, suggesting a role for catalase in increasing the kinetics of the cathodic reaction and, consequently, the global corrosion process. This correlates with oxygen uptake kinetics, as determined by differential pulse voltammetry on a pyrolytic graphite electrode modified with cobalt phthalocyanine, which was higher in the presence of wild type E. coli. When H2O2 was deliberately added to the culture medium, wild type E. coli catalyzed oxygen disproportionation more efficiently than the mutant derivative, thus limiting H2O2 accumulation in the medium and, hence, bacterial poisoning. In fact, the reduced adhesion of mutant cells to the metal substrate is apparently the result of H2O2 accumulation in the culture broth. Thus, the rapid consumption of oxygen and peroxide in the presence of wild type E. coli is associated with the catalysis of H2O2 disproportionation to water and oxygen. On the stainless steel, however, a dual mechanism of oxygen reduction, i.e. through formation of hydrogen peroxide and by formation

  8. Bacterial Catalase in the Microsporidian Nosema locustae: Implications for Microsporidian Metabolism and Genome Evolution

    OpenAIRE

    Fast, Naomi M; Law, Joyce S.; Williams, Bryony A P; Patrick J Keeling

    2003-01-01

    Microsporidia constitute a group of extremely specialized intracellular parasites that infect virtually all animals. They are highly derived, reduced fungi that lack several features typical of other eukaryotes, including canonical mitochondria, flagella, and peroxisomes. Consistent with the absence of peroxisomes in microsporidia, the recently completed genome of the microsporidian Encephalitozoon cuniculi lacks a gene for catalase, the major enzymatic marker for the organelle. We show, howe...

  9. Scavenging of free radicals in gas-phase mainstream cigarette smoke by immobilized catalase at filter level.

    Science.gov (United States)

    Lu, Xin; Hua, Zhaozhe; Du, Guocheng; Ma, Xiaolong; Cao, Jianhua; Yang, Zhanping; Chen, Jian

    2008-03-01

    Catalase is well known as capable of inducing the decomposition of H(2)O(2). In this study, a kind of immobilized catalase (entrapped in cross-linked chitosan beads) was dispersed in conventional acetate filter as an antioxidant additive. Quantitative estimation of the free radicals in mainstream cigarette smoke (MCS) was performed to address the effect of this modified filter. It was found that the levels of PBN adduct and NO(*)/NO(2)(*) associated with the gas-phase mainstream cigarette smoke (GPCS) were efficiently decreased by approximately 40% through catalase filtering. Besides, the modified filter was found to lower the MCS-induced adverse biological effects including lipid peroxidation and mutagenicity. This was proved to be substantially attributed to the catalase-dependent breakdown of NO(*), which was stimulated by some of peroxides (most probably being H(2)O(2)), the dismutation products of tar particulate matters (TPM). These results highlighted a promising approach to reduce the smoking-associated health risks to passive smokers. Moreover, the mechanisms of catalase filtering may be helpful for the development of appropriate immobilized enzyme systems to be applied for reducing health risks associated with gaseous pollutants. PMID:18344119

  10. The localization of catalase in the pulmonary alveolar macrophage.

    Science.gov (United States)

    Davies, P; Drath, D B; Engel, E E; Huber, G L

    1979-02-01

    A combined biochemical and cytochemical study of catalase was performed on alveolar macrophages lavaged from the lungs of adult male rats. Biochemically, catalase activity was present in both a high-speed granule fraction and in the supernatant. The granule-associated activity exhibited latency. Two methods of cell breakage, sonication and homogenization, yielded similar levels and distributions of catalase activity. Catalase activity in whole cells was identified cytochemically by the alkaline diaminobenzidine method and was localized within membrane-lined cytoplasmic granules similar in size to microperoxisomes and associated with cisternae of smooth endoplasmic reticulum. Localization of the reaction product was inhibited by 0.04 M aminotriazole, by cyanide, and by boiling prior to incubation. The cytochemical reaction continued in the absence of exogenous peroxide, but could be prevented by addition of catalase or pyruvate to the peroxide-free medium. Enzyme activity was also localized within a portion of the membrane-bound granules present in the cell fractions used for the biochemical assays. PMID:431040

  11. Catalase, glutathione peroxidase, metabolic syndrome, superoxide dismutase

    OpenAIRE

    Tarsikah; Herman Susanto; Herri S. Sastramihardja

    2012-01-01

    Labor pain is part of a normal process, which often causes physiological and psychological stress to mother. These stress have impact to both mother and fetus. Largely (90%) labor comes with pain and in some cases severe pain. Non-pharmacological approach is one of alternatives to reduce labor pain. This research aims to analyse the analgesic effect of lavender aromatherapy inhalation on labor pain in primigravida in the active phase. The study was pra-experimental by observing one group befo...

  12. Cytoplasmic superoxide dismutase and catalase activity and resistance to radiation lethality in murine tumor cells

    International Nuclear Information System (INIS)

    Reduced species of molecular oxygen are produced by the interaction of ionizing radiation with aqueous solutions containing molecular oxygen. The enzymes catalase and superoxide dismutase (SOD) are thought to function in vivo as scavengers of metabolically produced peroxide and superoxide respectively. SOD has been shown to protect against the lethal effects of ionizing radiation in vitro and in vivo. The authors have investigated the relationship between the cytosolic SOD catalase content and the sensitivity to radiation lethality of a number of murine cell lines (402AX, EL-4, MB-2T3, MB-4, MEL, P-815, SAI, SP-2, and SV-3T3). K/sub i/(CN-) for murine Cu-Zn-SOD was determined to be 6.8 x 10-6 M. No cytosolic Mn-SOD activity was found in any of the cell lines studied. No correlation was found between the cytosolic Cu-Zn-SOD or cytosolic catalase activity and the resistance to radiation lethality or the murine cell lines studied

  13. Catalase, glutathione peroxidase, metabolic syndrome, superoxide dismutase

    Directory of Open Access Journals (Sweden)

    Tarsikah

    2012-03-01

    Full Text Available Labor pain is part of a normal process, which often causes physiological and psychological stress to mother. These stress have impact to both mother and fetus. Largely (90% labor comes with pain and in some cases severe pain. Non-pharmacological approach is one of alternatives to reduce labor pain. This research aims to analyse the analgesic effect of lavender aromatherapy inhalation on labor pain in primigravida in the active phase. The study was pra-experimental by observing one group before and after treatment. The group involved 30 parturients in RB Kasih Ibu Jatirogo district of Tuban, East Java. The sampling method was based on consecutive admission. The variables were measured by using numerical rating scales (NRS. Univariable quantitative analysis was applied to describe the pain before and after treatment. Wilcoxon signed ranks test bivariable quantitative analysis was used to investigate pain relief with significance level of p<0.05. The univariable analysis result revealed that mean pain score before treatment was 7.3 (SD 1.1 and after treatment 5.9 (SD 1.4. Wilcoxon signed ranks test result showed significant pain relief after lavender aromatherapy inhalation (Z=-4.338, p=0.000. The research shows that there is a reduction of labor pain after lavender aromatherapy inhalation.

  14. Over-expression of the catalytic core of mitochondrial DNA (mtDNA) polymerase in the nervous system of Drosophila melanogaster reduces median life span by inducing mtDNA depletion

    Science.gov (United States)

    Martínez-Azorín, Francisco; Calleja, Manuel; Hernández-Sierra, Rosana; Farr, Carol L.; Kaguni, Laurie S.; Garesse, Rafael

    2016-01-01

    DNA polymerase γ (pol γ) is the sole DNA polymerase devoted to mitochondrial DNA (mtDNA) replication. We have characterized the molecular and physiological effects of over-expression of the catalytic subunit of pol γ, pol γ-α, in the nervous system of Drosophila melanogaster using the upstream activation sequence (UAS)/yeast transcriptional activator by binding to UAS (GAL4) system. Tissue-specific over-expression of pol γ-α was confirmed by immunoblot analysis, whereas the very low levels of endogenous protein are undetectable in UAS or GAL4 control lines. The transgenic flies over-expressing pol γ-α in the nervous system showed a moderate increase in pupal lethality, and a significant decrease in the median life span of adult flies. Moreover, these flies displayed a decrease in the rate of synthesis of mtDNA, which is accompanied by a significant mtDNA depletion, and a corresponding decrease in the levels of mitochondrial transcription factor A (mtTFA). Biochemical analysis showed an oxidative phosphorylation (OXPHOS) defect in transgenic flies, which were more susceptible to oxidative stress. Although we did not detect apoptosis in the nervous system of adult transgenic flies, brains of larvae over-expressing pol γ-α showed evidence of increased cell death that correlates with the observed phenotypes. Our data establish an animal model that mimics some of the features of human mtDNA depletion syndromes. PMID:17999718

  15. Using superoxide dismutase/catalase mimetics to manipulate the redox environment of neural precursor cells

    International Nuclear Information System (INIS)

    Past work has shown that neural precursor cells are predisposed to redox sensitive changes, and that oxidative stress plays a critical role in the acute and persistent changes that occur within the irradiated CNS. Irradiation leads to a marked rise in reactive oxygen species (ROS) that correlates with oxidative endpoints in vivo and reductions in neuro-genesis. To better understand the impact of oxidative stress on neural precursor cells, and to determine if radiation-induced oxidative damage and precursor cell loss after irradiation could be reduced, a series of antioxidant compounds (EUK-134, EUK-163, EUK-172, EUK-189) were tested, three of which possess both superoxide dismutase (SOD) and catalase activities and one (EUK-163) whose only significant activity is SOD. Our results show that these SOD/catalase mimetics apparently increase the oxidation of a ROS-sensitive fluorescent indicator dye, particularly after short (12 h) treatments, but that longer treatments (24 h) decrease oxidation attributable to radiation-induced ROS. Similarly, other studies found that cells incubated with CuZnSOD showed some increase in intracellular ROS levels. Subsequent data suggested that the dye-oxidising capabilities of the EUK compounds were linked to differences in their catalase activity and, most likely, their ability to catalyse per-oxidative pathways. In unirradiated mice, the EUK-134 analogue induced some decrease of proliferating precursor cells and immature neurons 48 h after radiation, an effect that may be attributable to cytotoxicity and/or inhibition of precursor proliferation. In irradiated mice, a single injection of EUK-134 was not found to be an effective radioprotector at acute times (48 h). The present results support continued development of our in vitro model as a tool for predicting certain in vivo responses, and suggest that in some biological systems the capability to scavenge superoxide but produce excess H2O2, as is known for CuZnSOD, may be potentially

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

    Science.gov (United States)

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

    2004-06-01

    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

  17. Catalase Deficiency Accelerates Diabetic Renal Injury Through Peroxisomal Dysfunction

    OpenAIRE

    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...

  18. Hepatic catalase activity after whole-body irradiation of the mouse

    International Nuclear Information System (INIS)

    Using biochemical techniques, the effect of irradiation on catalase rate of different tissues is studied. With cytochemistry, the decrease of catalase activity is studied in situ, after exposure to great ionizing radiation doses

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

    OpenAIRE

    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. Differen...

  20. Effect of menadione and hydrogen peroxide on catalase activity in Saccharomyces yeast strains

    OpenAIRE

    Nadejda EFREMOVA; Elena MOLODOI; Agafia USATÎI; Ludmila FULGA; Tamara BORISOVA

    2013-01-01

    It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein) compared with other samples. Maximum increase of ...

  1. Calpastatin overexpression reduces oxidative stress-induced mitochondrial impairment and cell death in human neuroblastoma SH-SY5Y cells by decreasing calpain and calcineurin activation, induction of mitochondrial fission and destruction of mitochondrial fusion.

    Science.gov (United States)

    Tangmansakulchai, Kulvadee; Abubakar, Zuroida; Kitiyanant, Narisorn; Suwanjang, Wilasinee; Leepiyasakulchai, Chaniya; Govitrapong, Piyarat; Chetsawang, Banthit

    2016-09-01

    Calpain is an intracellular Ca(2+)-dependent protease, and the activation of calpain has been implicated in neurodegenerative diseases. Calpain activity can be regulated by calpastatin, an endogenous specific calpain inhibitor. Several lines of evidence have demonstrated a potential role of calpastatin in preventing calpain-mediated pathogenesis. Additionally, several studies have revealed that calpain activation and mitochondrial damage are involved in the cell death process; however, recent evidence has not clearly indicated a neuroprotective mechanism of calpastatin against calpain-dependent mitochondrial impairment in the process of neuronal cell death. Therefore, the purpose of this study was to investigate the potential ability of calpastatin to inhibit calpain activation and mitochondrial impairment in oxidative stress-induced neuron degeneration. Calpastatin was stably overexpressed in human neuroblastoma SH-SY5Y cells. In non-calpastatin overexpressing SH-SY5Y cells, hydrogen peroxide significantly decreased cell viability, superoxide dismutase activity, mitochondrial membrane potential, ATP production and mitochondrial fusion protein (Opa1) levels in the mitochondrial fraction but increased reactive oxygen species formation, calpain and calcineurin activation, mitochondrial fission protein (Fis1 and Drp1) levels in the mitochondrial fraction and apoptotic cells. Nevertheless, these toxic effects were abolished in hydrogen peroxide-treated calpastatin-overexpressing SH-SY5Y cells. The results of the present study demonstrate the potential ability of calpastatin to diminish calpain and calcineurin activation and mitochondrial impairment in neurons that are affected by oxidative damage. PMID:27453331

  2. Radiation-induced inactivation of bovine liver catalase in nitrous oxide-saturated solutions

    International Nuclear Information System (INIS)

    Radiation-induced inactivation of catalase by .OH/H. radicals was studied. It was found that inactivation yield of catalase depended on the dose. Optical spectrum of irradiated catalase showed that no redox processes in active site of enzyme occurred as a result of .OH/H. interaction. (author) 19 refs.; 3 figs

  3. Rapid catalase supplemental test for identification of members of the family Enterobacteriaceae.

    OpenAIRE

    Chester, B; Moskowitz, L B

    1987-01-01

    A simple, rapid, semiquantitative slide catalase test useful for differentiating members of the family Enterobacteriaceae is described. Judging by the time required for appearance of oxygen bubbles in 3% hydrogen peroxide, the immediate catalase reactors were Yersinia, Serratia, Proteus, Morganella, Providencia, Cedecea, and Hafnia spp. The delayed catalase reactors were Escherichia, Shigella, Klebsiella, Enterobacter, Salmonella, Citrobacter, Edwardsiella, Kluyvera, and Tatumella spp. This i...

  4. Structure–Function Relationships in Fungal Large-Subunit Catalases

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, A.; Valdez, V; Rudino-Pinera, E; Horjales, E; Hansberg, W

    2009-01-01

    Neurospora crassa has two large-subunit catalases, CAT-1 and CAT-3. CAT-1 is associated with non-growing cells and accumulates particularly in asexual spores; CAT-3 is associated with growing cells and is induced under different stress conditions. It is our interest to elucidate the structure-function relationships in large-subunit catalases. Here we have determined the CAT-3 crystal structure and compared it with the previously determined CAT-1 structure. Similar to CAT-1, CAT-3 hydrogen peroxide (H{sub 2}O{sub 2}) saturation kinetics exhibited two components, consistent with the existence of two active sites: one saturated in the millimolar range and the other in the molar range. In the CAT-1 structure, we found three interesting features related to its unusual kinetics: (a) a constriction in the channel that conveys H{sub 2}O{sub 2} to the active site; (b) a covalent bond between the tyrosine, which forms the fifth coordination bound to the iron of the heme, and a vicinal cysteine; (c) oxidation of the pyrrole ring III to form a cis-hydroxyl group in C5 and a cis-{gamma}-spirolactone in C6. The site of heme oxidation marks the starts of the central channel that communicates to the central cavity and the shortest way products can exit the active site. CAT-3 has a similar constriction in its major channel, which could function as a gating system regulated by the H{sub 2}O{sub 2} concentration before the gate. CAT-3 functional tyrosine is not covalently bonded, but has instead the electron relay mechanism described for the human catalase to divert electrons from it. Pyrrole ring III in CAT-3 is not oxidized as it is in other large-subunit catalases whose structure has been determined. Different in CAT-3 from these enzymes is an occupied central cavity. Results presented here indicate that CAT-3 and CAT-1 enzymes represent a functional group of catalases with distinctive structural characteristics that determine similar kinetics.

  5. Structure-function relationships in fungal large-subunit catalases.

    Science.gov (United States)

    Díaz, Adelaida; Valdés, Víctor-Julián; Rudiño-Piñera, Enrique; Horjales, Eduardo; Hansberg, Wilhelm

    2009-02-13

    Neurospora crassa has two large-subunit catalases, CAT-1 and CAT-3. CAT-1 is associated with non-growing cells and accumulates particularly in asexual spores; CAT-3 is associated with growing cells and is induced under different stress conditions. It is our interest to elucidate the structure-function relationships in large-subunit catalases. Here we have determined the CAT-3 crystal structure and compared it with the previously determined CAT-1 structure. Similar to CAT-1, CAT-3 hydrogen peroxide (H(2)O(2)) saturation kinetics exhibited two components, consistent with the existence of two active sites: one saturated in the millimolar range and the other in the molar range. In the CAT-1 structure, we found three interesting features related to its unusual kinetics: (a) a constriction in the channel that conveys H(2)O(2) to the active site; (b) a covalent bond between the tyrosine, which forms the fifth coordination bound to the iron of the heme, and a vicinal cysteine; (c) oxidation of the pyrrole ring III to form a cis-hydroxyl group in C5 and a cis-gamma-spirolactone in C6. The site of heme oxidation marks the starts of the central channel that communicates to the central cavity and the shortest way products can exit the active site. CAT-3 has a similar constriction in its major channel, which could function as a gating system regulated by the H(2)O(2) concentration before the gate. CAT-3 functional tyrosine is not covalently bonded, but has instead the electron relay mechanism described for the human catalase to divert electrons from it. Pyrrole ring III in CAT-3 is not oxidized as it is in other large-subunit catalases whose structure has been determined. Different in CAT-3 from these enzymes is an occupied central cavity. Results presented here indicate that CAT-3 and CAT-1 enzymes represent a functional group of catalases with distinctive structural characteristics that determine similar kinetics. PMID:19109972

  6. Overexpression of the wheat aquaporin gene, TaAQP7, enhances drought tolerance in transgenic tobacco.

    Science.gov (United States)

    Zhou, Shiyi; Hu, Wei; Deng, Xiaomin; Ma, Zhanbing; Chen, Lihong; Huang, Chao; Wang, Chen; Wang, Jie; He, Yanzhen; Yang, Guangxiao; He, Guangyuan

    2012-01-01

    Aquaporin (AQP) proteins have been shown to transport water and other small molecules through biological membranes, which is crucial for plants to combat stress caused by drought. However, the precise role of AQPs in drought stress response is not completely understood in plants. In this study, a PIP2 subgroup gene AQP, designated as TaAQP7, was cloned and characterized from wheat. Expression of TaAQP7-GFP fusion protein revealed its localization in the plasma membrane. TaAQP7 exhibited high water channel activity in Xenopus laevis oocytes and TaAQP7 transcript was induced by dehydration, and treatments with polyethylene glycol (PEG), abscisic acid (ABA) and H(2)O(2). Further, TaAQP7 was upregulated after PEG treatment and was blocked by inhibitors of ABA biosynthesis, implying that ABA signaling was involved in the upregulation of TaAQP7 after PEG treatment. Overexpression of TaAQP7 increased drought tolerance in tobacco. The transgenic tobacco lines had lower levels of malondialdehyde (MDA) and H(2)O(2), and less ion leakage (IL), but higher relative water content (RWC) and superoxide dismutase (SOD) and catalase (CAT) activities when compared with the wild type (WT) under drought stress. Taken together, our results show that TaAQP7 confers drought stress tolerance in transgenic tobacco by increasing the ability to retain water, reduce ROS accumulation and membrane damage, and enhance the activities of antioxidants. PMID:23285044

  7. Overexpression of the wheat aquaporin gene, TaAQP7, enhances drought tolerance in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Shiyi Zhou

    Full Text Available Aquaporin (AQP proteins have been shown to transport water and other small molecules through biological membranes, which is crucial for plants to combat stress caused by drought. However, the precise role of AQPs in drought stress response is not completely understood in plants. In this study, a PIP2 subgroup gene AQP, designated as TaAQP7, was cloned and characterized from wheat. Expression of TaAQP7-GFP fusion protein revealed its localization in the plasma membrane. TaAQP7 exhibited high water channel activity in Xenopus laevis oocytes and TaAQP7 transcript was induced by dehydration, and treatments with polyethylene glycol (PEG, abscisic acid (ABA and H(2O(2. Further, TaAQP7 was upregulated after PEG treatment and was blocked by inhibitors of ABA biosynthesis, implying that ABA signaling was involved in the upregulation of TaAQP7 after PEG treatment. Overexpression of TaAQP7 increased drought tolerance in tobacco. The transgenic tobacco lines had lower levels of malondialdehyde (MDA and H(2O(2, and less ion leakage (IL, but higher relative water content (RWC and superoxide dismutase (SOD and catalase (CAT activities when compared with the wild type (WT under drought stress. Taken together, our results show that TaAQP7 confers drought stress tolerance in transgenic tobacco by increasing the ability to retain water, reduce ROS accumulation and membrane damage, and enhance the activities of antioxidants.

  8. Effect of catalase on the liquid storage of mithun (Bos frontalis) semen

    Institute of Scientific and Technical Information of China (English)

    P Peruma; JK Chamuah; C Rajkhowa

    2013-01-01

    Objective: To assess the effect of catalase (CAT) on sperm motility, viability, total sperm abnormality, acrosomal and plasma membrane integrity, enzymatic profiles such as aspartate amino transaminase (AST), alanine amino transaminase (ALT), biochemical profiles such as cholesterol efflux and malonaldehyde (MDA) production and antioxidant profiles such as reduced glutathione (GSH), superoxide dismutase (SOD) and total antioxidant capacity (TAC). Methods: Total numbers of 50 ejaculates were collected twice a week from eight mithun bulls and semen was split into four equal aliquots, diluted with the TEYC extender. Group 1: semen without additives (control), group 2 to group 4: semen was diluted with 50 U/mL, 100 U/mL and 150 U/mL of catalase, respectively. These seminal, enzymatic, biochemical and antioxidant profiles were assessed at 5 ℃ for 0, 6, 12, 24 and 30 h of incubation. Results: Inclusion of catalase into diluent resulted in significant (P < 0.05) decrease in percentages of dead spermatozoa, abnormal spermatozoa and acrosomal abnormalities at different hours of storage periods as compared with control group. Additionally, CAT at 50 and 150 U/mL were inferior to CAT 100 U/mL treatments as regards to these characteristics and CAT at 100 U/mL has significant improvement in quality of mithun semen in in- vitro stored for up to 30 h.Conclusions:It was concluded that the possible protective effects of CAT on sperm parameters are it prevent efflux of cholesterol from cell membrane, MDA production and protect the function of antioxidants during preservation.

  9. Influence of Foreign DNA Introduction and Periplasmic Expression of Recombinant Human Interleukin-2 on Hydrogen Peroxide Quantity and Catalase Activity in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Lena Mahmoudi Azar

    2013-08-01

    Full Text Available Purpose: Oxidative stress is generated through imbalance between composing and decomposing of reactive oxygen species (ROS. This kind of stress was rarely discussed in connection with foreign protein production in Escherichia coli. Effect of cytoplasmic recombinant protein expression on Hydrogen peroxide concentration and catalase activity was previously reported. In comparison with cytoplasm, periplasmic space has different oxidative environment. Therefore, in present study we describe the effect of periplasmic expression of recombinant human interleukin-2 (hIL-2 on H2O2 concentration and catalase activity in Escherichia coli and their correlation with cell growth. Methods: Having constructed pET2hIL2 vector, periplasmic expression of hIL-2 was confirmed. Then, H2O2 concentration and catalase activity were determined at various ODs. Wild type and empty vector transformed cells were used as negative controls. Results: It was shown that H2O2 concentration in hIL-2 expressing cells was significantly higher than its concentration in wild type and empty vector transformed cells. Catalase activity and growth rate reduced significantly in hIL-2 expressing cells compared to empty vector transformed and wild type cells. Variation of H2O2 concentration and catalase activity is intensive in periplasmic hIL-2 expressing cells than empty vector containing cells. Correlation between H2O2 concentration elevation and catalase activity reduction with cell growth depletion are also demonstrated. Conclusion: Periplasmic expression of recombinant hIL-2 elevates the host cell’s hydrogen peroxide concentration possibly due to reduced catalase activity which has consequent suppressive effect on growth rate.

  10. Two divergent catalase genes are differentially regulated during Aspergillus nidulans development and oxidative stress.

    OpenAIRE

    Kawasaki, L; Wysong, D; Diamond, R.; Aguirre, J.

    1997-01-01

    Catalases are ubiquitous hydrogen peroxide-detoxifying enzymes that are central to the cellular antioxidant response. Of two catalase activities detected in the fungus Aspergillus nidulans, the catA gene encodes the spore-specific catalase A (CatA). Here we characterize a second catalase gene, identified after probing a genomic library with catA, and demonstrate that it encodes catalase B. This gene, designated catB, predicts a 721-amino-acid polypeptide (CatB) showing 78% identity to an Aspe...

  11. Ultraviolet Light B-Mediated Inhibition of Skin Catalase Activity Promotes Gr-1+CD11b+ Myeloid Cell Expansion

    OpenAIRE

    Sullivan, Nicholas J.; Tober, Kathleen L.; Burns, Erin M.; Schick, Jonathan S.; Riggenbach, Judith A.; Mace, Thomas A.; Bill, Matthew A.; Gregory S. Young; Oberyszyn, Tatiana M.; Lesinski, Gregory B.

    2011-01-01

    Skin cancer incidence and mortality are higher in men compared to women, but the causes of this sex discrepancy remain largely unknown. Ultraviolet light exposure induces cutaneous inflammation and neutralizes cutaneous antioxidants. Gr-1+CD11b+ myeloid cells are heterogeneous bone marrow-derived cells that promote inflammation-associated carcinogenesis. Reduced activity of catalase, an antioxidant present within skin, has been associated with skin carcinogenesis. We utilized the outbred, imm...

  12. The Mycobacterial LysR-Type Regulator OxyS Responds to Oxidative Stress and Negatively Regulates Expression of the Catalase-Peroxidase Gene

    OpenAIRE

    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 ...

  13. Ability of recombinant human catalase to suppress inflammation of the murine lung induced by influenza A.

    Science.gov (United States)

    Shi, Xunlong; Shi, Zhihui; Huang, Hai; Zhu, Hongguang; Zhou, Pei; Zhu, Haiyan; Ju, Dianwen

    2014-06-01

    Influenza A virus pandemics and emerging antiviral resistance highlight the urgent need for novel generic pharmacological strategies that reduce both viral replication and inflammation of the lung. We have previously investigated the therapeutic efficacy of recombinant human catalase (rhCAT) against viral pneumonia in mice, but the protection mechanisms involved were not explored. In the present study, we have performed a more in-depth analysis covering survival, lung inflammation, immune cell responses, production of cytokines, and inflammation signaling pathways in mice. Male imprinting control region mice were infected intranasally with high pathogenicity (H1N1) influenza A virus followed by treatment with recombinant human catalase. The administration of rhCAT resulted in a significant reduction in inflammatory cell infiltration (e.g., macrophages and neutrophils), inflammatory cytokine levels (e.g., IL-2, IL-6, TNF-α, IFN-γ), the level of the intercellular adhesion molecule 1 chemokine and the mRNA levels of toll-like receptors TLR-4, TLR-7, and NF-κB, as well as partially maintaining the activity of the antioxidant enzymes system. These findings indicated that rhCAT might play a key protective role in viral pneumonia of mice via suppression of inflammatory immune responses. PMID:24385240

  14. A gasometric method to determine erythrocyte catalase activity

    Directory of Open Access Journals (Sweden)

    A.J.S. Siqueira

    1999-09-01

    Full Text Available 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 KHb, 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.

  15. Catalase degradation in sunflower cotyledons during peroxisome transition from glyoxysomal to leaf peroxisomal function

    International Nuclear Information System (INIS)

    First order rate constant for the degradation (degradation constants) of catalase in the cotyledons of sunflower (Helianthus annuus L.) were determined by measuring the loss of catalase containing 14C-labeled heme. During greening of the cotyledons, a period when peroxisomes change from glyoxysomal to leaf peroxisomal function, the degradation of glyoxysomal catalase is significantly slower than during all other stages of cotyledon development in light or darkness. The degradation constant during the transition stage of peroxisome function amounts to 0.205 day-1 in contrast to the constants ranging from 0.304 day-1 to 0.515 day-1 during the other developmental stages. Density labeling experiments comprising labeling of catalase with 2H2O and its isopycnic centrifugation on CsCl gradients demonstrated that the determinations of the degradation constants were not substantially affected by reutilization of 14C-labeled compounds for catalase synthesis. The degradation constants for both glyoxysomal catalase and catalase synthesized during the transition of peroxisome function do not differ. This was shown by labeling the catalases with different isotopes and measuring the isotope ratio during the development of the cotyledons. The results are inconsistent with the concept that an accelerated and selective degradation of glyoxysomes underlies the change in peroxisome function. The data suggest that catalase degradation is at least partially due to an individual turnover of catalase and does not only result from a turnover of the whole peroxisomes

  16. Effect of menadione and hydrogen peroxide on catalase activity in Saccharomyces yeast strains

    Directory of Open Access Journals (Sweden)

    Nadejda EFREMOVA

    2013-05-01

    Full Text Available It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein compared with other samples. Maximum increase of catalase activity with 50-60% compared to the reference sample was established in the case of hydrogen peroxide and menadione utilization in optimal concentrations of 15 and 10 mM. This research has been demonstrated the potential benefits of application of hydrogen peroxide and menadione as stimulatory factors of catalase activity in Saccharomyces yeasts.

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

    OpenAIRE

    Haas, Albert; Brehm, Klaus; Kreft, Jürgen; Goebel, Werner

    2011-01-01

    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 se...

  18. The role of cytoplasmic catalase in dehydration tolerance of Saccharomyces cerevisiae

    OpenAIRE

    França, Mauro Braga; Panek, Anita Dolly; Eleutherio, Elis Cristina Araujo

    2005-01-01

    In this study, we investigated the role played by cytoplasmic catalase (Ctt1) in resistance against water loss using the yeast Saccharomyces cerevisiae as eukaryotic cell model. Comparing a mutant possessing a specific lesion in CTT1 with its parental strain, it was observed that both control and ctt1 strains exhibited increased levels of lipid peroxidation after dehydration, suggesting that catalase does not protect membranes during drying. Although the ctt1 strain has only 1 catalase isofor...

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

    Science.gov (United States)

    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

  20. The relevance of the non-canonical PTS1 of peroxisomal catalase

    OpenAIRE

    Williams, Chris; Aksam, Eda Bener; Gunkel, Katja; Veenhuis, Marten; van der Klei, Ida J.

    2012-01-01

    Catalase is sorted to peroxisomes via a C-terminal peroxisomal targeting signal 1 (PTS1), which binds to the receptor protein Pex5. Analysis of the C-terminal sequences of peroxisomal catalases from various species indicated that catalase never contains the typical C-terminal PTS1 tripeptide-SKL, but invariably is sorted to peroxisomes via a non-canonical sorting sequence. We analyzed the relevance of the non-canonical PTS1 of catalase of the yeast Hansenula polymorpha (-SKI). Using isotherma...

  1. Cloning and Sequencing of a Candida albicans Catalase Gene and Effects of Disruption of This Gene†

    OpenAIRE

    Wysong, Deborah R.; Christin, Laurent; Sugar, Alan M.; Robbins, Phillips W.; Diamond, Richard D.

    1998-01-01

    Catalase plays a key role as an antioxidant, protecting aerobic organisms from the toxic effects of hydrogen peroxide, and in some cases has been postulated to be a virulence factor. To help elucidate the function of catalase in Candida albicans, a single C. albicans-derived catalase gene, designated CAT1, was isolated and cloned. Degenerate PCR primers based on highly conserved areas of other fungal catalase genes were used to amplify a 411-bp product from genomic DNA of C. albicans ATCC 102...

  2. Molecular Characterization of a Catalase Null Allele at the Cat3 Locus in Maize

    OpenAIRE

    Wadsworth, G. J.; Scandalios, J G

    1990-01-01

    Previous analysis has identified line IDS28 of maize (Zea mays L.) as being homozygous for a Catalase-3 (Cat3) null allele. Catalase-3 (CAT-3) protein-specific antibodies could not detect CAT-3 in extracts of several tissues of IDS28, which in a typical maize line possess CAT-3. The absence of CAT-3 resulted in a significant decrease in total catalase activity in those tissues where CAT-3 is the predominant catalase isozyme. RNA blot analysis indicated that IDS28 does not accumulate Cat3 tran...

  3. Reactive oxygen species detoxification by catalase is a major determinant of fecundity in the mosquito Anopheles gambiae.

    Science.gov (United States)

    DeJong, Randall J; Miller, Lisa M; Molina-Cruz, Alvaro; Gupta, Lalita; Kumar, Sanjeev; Barillas-Mury, Carolina

    2007-02-13

    The mosquito Anopheles gambiae is a primary vector of Plasmodium parasites in Africa. The effect of aging on reproductive output in A. gambiae females from three strains that differ in their ability to melanize Plasmodium and in their systemic levels of hydrogen peroxide (H2O2), a reactive oxygen species (ROS), was analyzed. The number of eggs oviposited after the first blood meal decreases with age in all strains; however, this decline was much more pronounced in the G3 (unselected) and R (refractory to Plasmodium infection) strains than in the S (highly susceptible to Plasmodium) strain. Reduction of ROS levels in G3 and R females by administration of antioxidants reversed this age-related decline in fecundity. The S and G3 strains were fixed for two functionally different catalase alleles that differ at the second amino acid position (Ser2Trp). Biochemical analysis of recombinant proteins revealed that the Trp isoform has lower specific activity and higher Km than the Ser isoform, indicating that the former is a less efficient enzyme. The Trp-for-Ser substitution appears to destabilize the functional tetrameric form of the enzyme. Both alleles are present in the R strain, and Ser/Ser females had significantly higher fecundity than Trp/Trp females. Finally, a systemic reduction in catalase activity by dsRNA-mediated knockdown significantly reduced the reproductive output of mosquito females, indicating that catalase plays a central role in protecting the oocyte and early embryo from ROS damage. PMID:17284604

  4. Reactive oxygen species detoxification by catalase is a major determinant of fecundity in the mosquito Anopheles gambiae

    Science.gov (United States)

    DeJong, Randall J.; Miller, Lisa M.; Molina-Cruz, Alvaro; Gupta, Lalita; Kumar, Sanjeev; Barillas-Mury, Carolina

    2007-01-01

    The mosquito Anopheles gambiae is a primary vector of Plasmodium parasites in Africa. The effect of aging on reproductive output in A. gambiae females from three strains that differ in their ability to melanize Plasmodium and in their systemic levels of hydrogen peroxide (H2O2), a reactive oxygen species (ROS), was analyzed. The number of eggs oviposited after the first blood meal decreases with age in all strains; however, this decline was much more pronounced in the G3 (unselected) and R (refractory to Plasmodium infection) strains than in the S (highly susceptible to Plasmodium) strain. Reduction of ROS levels in G3 and R females by administration of antioxidants reversed this age-related decline in fecundity. The S and G3 strains were fixed for two functionally different catalase alleles that differ at the second amino acid position (Ser2Trp). Biochemical analysis of recombinant proteins revealed that the Trp isoform has lower specific activity and higher Km than the Ser isoform, indicating that the former is a less efficient enzyme. The Trp-for-Ser substitution appears to destabilize the functional tetrameric form of the enzyme. Both alleles are present in the R strain, and Ser/Ser females had significantly higher fecundity than Trp/Trp females. Finally, a systemic reduction in catalase activity by dsRNA-mediated knockdown significantly reduced the reproductive output of mosquito females, indicating that catalase plays a central role in protecting the oocyte and early embryo from ROS damage. PMID:17284604

  5. Modulatory effect of pineapple peel extract on lipid peroxidation, catalase activity and hepatic biomarker levels in blood plasma of alcohol-induced oxidative stressed rats

    Institute of Scientific and Technical Information of China (English)

    Okafor OY; Erukainure OL; Ajiboye JA; Adejobi RO; Owolabi FO; Kosoko SB

    2011-01-01

    Objective: To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation, changes in catalase activities and hepatic biochemical marker levels in blood plasma. Methods: Oxidative stress was induced by oral administration of ethanol (20% w/v) at a dosage of 5 mL/kg bw in rats. After 28 days of treatment, the rats were fasted overnight and sacrificed by cervical dislocation. Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min. The plasma was analyzed to evaluate malondialdehyde (MDA), catalase activity, aspartate aminotransferase (AST), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) concentrations. Results: Administration of alcohol caused a drastic increase (87.74%) in MDA level compared with the control. Pineapple peel extract significantly reduced the MDA level by 60.16% at 2.5 mL/kg bw. Rats fed alcohol only had the highest catalase activity, treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity. Increased AST, ALP and ALT activities were observed in rats fed alcohol only respectively, treatment with pineapple peel extract drastically reduced their activities. Conclusions: The positive modulation of lipid peroxidation, catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcohol-induced oxidative stress is an indication of its protective ability in the management of alcohol-induced toxicity.

  6. Hand1 overexpression inhibits medulloblastoma metastasis.

    Science.gov (United States)

    Asuthkar, Swapna; Guda, Maheedhara R; Martin, Sarah E; Antony, Reuben; Fernandez, Karen; Lin, Julian; Tsung, Andrew J; Velpula, Kiran K

    2016-08-19

    Medulloblastoma (MB) is the most frequent malignant pediatric brain tumor. Current treatment includes surgery, radiation and chemotherapy. However, ongoing treatment in patients is further classified according to the presence or absence of metastasis. Since metastatic medulloblastoma are refractory to current treatments, there is need to identify novel biomarkers that could be used to reduce metastatic potential, and more importantly be targeted therapeutically. Previously, we showed that ionizing radiation-induced uPAR overexpression is associated with increased accumulation of β-catenin in the nucleus. We further demonstrated that uPAR protein act as cytoplasmic sequestration factor for a novel basic helix-loop-helix transcription factor, Hand1. Among the histological subtypes classical and desmoplastic subtypes account for the majority while large cell/anaplastic variant is most commonly associated with metastatic disease. In this present study using immunohistochemical approach and patient data mining for the first time, we demonstrated that Hand1 expression is observed to be downregulated in all the subtypes of medulloblastoma. Previously we showed that Hand1 overexpression regulated medulloblastoma angiogenesis and here we investigated the role of Hand1 in the context of Epithelial-Mesenchymal Transition (EMT). Moreover, UW228 and D283 cells overexpressing Hand1 demonstrated decreased-expression of mesenchymal markers (N-cadherin, β-catenin and SOX2); metastatic marker (SMA); and increased expression of epithelial marker (E-cadherin). Strikingly, human pluripotent stem cell antibody array showed that Hand1 overexpression resulted in substantial decrease in pluripotency markers (Nanog, Oct3/4, Otx2, Flk1) suggesting that Hand1 expression may be essential to attenuate the EMT and our findings underscore a novel role for Hand1 in medulloblastoma metastasis. PMID:27297109

  7. Inherited catalase deficiency: is it benign or a factor in various age related disorders?

    Science.gov (United States)

    Góth, László; Nagy, Teréz

    2013-01-01

    Hydrogen peroxide was - and is still - considered toxic for a wide range of living organisms. Oxidative stress occurs when there is an excess of pro-oxidants over antioxidants and it has been implicated in several diseases. Catalase is involved in hydrogen peroxide catabolism and is important in defense against oxidative stress. Acatalasemia means the inherited near-total deficiency of catalase activity, usually in reference to red cell catalase. Acatalasemia was thought at first to be an asymptotic disorder. In the absence of catalase, neither the Japanese, or Hungarian acatalasemics nor acatalasemic mice had significantly increased blood glutathione peroxidase activity. In animal models, catalase deficient tissues show much slower rates of removal of extracellular hydrogen peroxide. In catalase knock-out mice, a decreased hydrogen peroxide removing capacity and increased reactive oxygen species formation were reported. Hydrogen peroxide may cause methemoglobinemia in patients with catalase deficiency. During anesthesia for a Japanese acatalasemic patient the disinfection with hydrogen peroxide solution caused severe methemoglobinemia. Patients with inherited catalase deficiency, who are treated with uric acid oxidase (rasburicase) may experience very high concentrations of hydrogen peroxide and may suffer from methemoglobinemia and hemolysis. The high (18.5%) prevalence of diabetes mellitus in inherited catalase deficient individuals and the earlier (10 years) manifestation of the disease may be attributed to the oxidative damage of oxidant sensitive, insulin producing pancreatic beta-cells. Ninety-seven of 114 acatalasemics had diseases related to oxidative stress and aging. The oxidative stress due to catalase deficiency could contribute to the manifestation of diabetes while for the other diseases it may be one of the factors in their causations. In summary, inherited catalase deficiency is associated with clinical features, pathologic laboratory test results

  8. Regulation of catalase activity in leaves of Nicotiana sylvestris by high CO sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Havir, E.A.; McHale, N.A. (Connecticut Agricultural Experiment Station, New Haven (USA))

    1989-03-01

    The effect of high CO{sub 2} (1% CO{sub 2}/21% O{sub 2}) on the activity of specific forms of catalase (CAT-1, -2, and -3) in seedling leaves of tobacco (Nicotiana sylvestris, Nicotiana tabacum) was examined. In high CO{sub 2} total catalase activity decreased by 50% in the first 2 days, followed by a more gradual decline in the next 4 days. The loss of total activity resulted primarily from a decrease in CAT-1 catalase. In contrast, the activity of CAT-3 catalase, a form with enhanced peroxidatic activity, increased 3-fold in high CO{sub 2} relative to air controls after 4 days. Short-term exposure to high CO{sub 2} indicated that the 50% loss of total activity occurs in the firs 12 hours. Catalase levels increased to normal within 12 hours after seedlings were returned to air. When seedlings were transferred to air after prolonged exposure to high CO{sub 2} (13 days), the levels of CAT-1 catalase were partially restored while CAT-3 remained at its elevated level. Levels of superoxide dismutase activity and those of several peroxisomal enzymes were not affected by high CO{sub 2}. Total catalase levels did not decline when seedlings were exposed to atmospheres of 0.04% CO{sub 2}/5% O{sub 2} or 0.04% CO{sub 2}/1% O{sub 2}, indicating that regulation of catalase in high CO{sub 2} is not related directly to suppression of photorespiration. Antibodies prepared against CAT-1 catalase from N. tabacum reacted strongly against CAT-1 catalase from both N. sylvestris and N. tabacum but not against CAT-3 catalase from either species.

  9. Mitochondrial targeted catalase suppresses invasive breast cancer in mice

    International Nuclear Information System (INIS)

    Treatment of invasive breast cancer has an alarmingly high rate of failure because effective targets have not been identified. One potential target is mitochondrial generated reactive oxygen species (ROS) because ROS production has been associated with changes in substrate metabolism and lower concentration of anti-oxidant enzymes in tumor and stromal cells and increased metastatic potential. Transgenic mice expressing a human catalase gene (mCAT) were crossed with MMTV-PyMT transgenic mice that develop metastatic breast cancer. All mice (33 mCAT positive and 23 mCAT negative) were terminated at 110 days of age, when tumors were well advanced. Tumors were histologically assessed for invasiveness, proliferation and metastatic foci in the lungs. ROS levels and activation status of p38 MAPK were determined. PyMT mice expressing mCAT had a 12.5 per cent incidence of high histological grade primary tumor invasiveness compared to a 62.5 per cent incidence in PyMT mice without mCAT. The histological grade correlated with incidence of metastasis with 56 per cent of PyMT mice positive for mCAT showing evidence of pulmonary metastasis compared to 85.4 per cent of PyMT mice negative for mCAT with pulmonary metastasis (p ≤ 0.05). PyMT tumor cells expressing mCAT had lower ROS levels and were more resistant to hydrogen peroxide-induced oxidative stress than wild type tumor cells, suggesting that mCAT has the potential of quenching intracellular ROS and subsequent invasive behavior. The metastatic tumor burden in PyMT mice expressing mCAT was 0.1 mm2/cm2 of lung tissue compared with 1.3 mm2/cm2 of lung tissue in PyMT mice expressing the wild type allele (p ≤ 0.01), indicating that mCAT could play a role in mitigating metastatic tumor progression at a distant organ site. Expression of mCAT in the lungs increased resistance to hydrogen peroxide-induced oxidative stress that was associated with decreased activation of p38MAPK suggesting ROS signaling is dependent on p38MAPK for

  10. Mitochondrial targeted catalase suppresses invasive breast cancer in mice

    Directory of Open Access Journals (Sweden)

    Morton John

    2011-05-01

    Full Text Available Abstract Background Treatment of invasive breast cancer has an alarmingly high rate of failure because effective targets have not been identified. One potential target is mitochondrial generated reactive oxygen species (ROS because ROS production has been associated with changes in substrate metabolism and lower concentration of anti-oxidant enzymes in tumor and stromal cells and increased metastatic potential. Methods Transgenic mice expressing a human catalase gene (mCAT were crossed with MMTV-PyMT transgenic mice that develop metastatic breast cancer. All mice (33 mCAT positive and 23 mCAT negative were terminated at 110 days of age, when tumors were well advanced. Tumors were histologically assessed for invasiveness, proliferation and metastatic foci in the lungs. ROS levels and activation status of p38 MAPK were determined. Results PyMT mice expressing mCAT had a 12.5 per cent incidence of high histological grade primary tumor invasiveness compared to a 62.5 per cent incidence in PyMT mice without mCAT. The histological grade correlated with incidence of metastasis with 56 per cent of PyMT mice positive for mCAT showing evidence of pulmonary metastasis compared to 85.4 per cent of PyMT mice negative for mCAT with pulmonary metastasis (p ≤ 0.05. PyMT tumor cells expressing mCAT had lower ROS levels and were more resistant to hydrogen peroxide-induced oxidative stress than wild type tumor cells, suggesting that mCAT has the potential of quenching intracellular ROS and subsequent invasive behavior. The metastatic tumor burden in PyMT mice expressing mCAT was 0.1 mm2/cm2 of lung tissue compared with 1.3 mm2/cm2 of lung tissue in PyMT mice expressing the wild type allele (p ≤ 0.01, indicating that mCAT could play a role in mitigating metastatic tumor progression at a distant organ site. Expression of mCAT in the lungs increased resistance to hydrogen peroxide-induced oxidative stress that was associated with decreased activation of p38MAPK

  11. Effects of cysteine on growth, protease production, and catalase activity of Pseudomonas fluorescens.

    OpenAIRE

    Himelbloom, B H; Hassan, H.M.

    1986-01-01

    Cysteine inhibits growth of and protease production by Pseudomonas fluorescens NC3. Catalase activity in P. fluorescens NC3 was increased by cysteine. The addition of exogenous hydrogen peroxide did not increase catalase activity, thus suggesting a role for the endogenous generation of hydrogen peroxide via the autoxidation of cysteine.

  12. Purification and characterization of an intracellular catalase-peroxidase from Penicillium simplicissimum

    NARCIS (Netherlands)

    Fraaije, Marco W.; Roubroeks, Hanno P.; Hagen, Wilfred R.; Berkel, Willem J.H. van

    1996-01-01

    The first dimeric catalase-peroxidase of eucaryotic origin, an intracellular hydroperoxidase from Penicillium simplicissimum which exhibited both catalase and peroxidase activities, has been isolated. The enzyme has an apparent molecular mass of about 170 kDa and is composed of two identical subunit

  13. Regulation of catalase in Neisseria gonorrhoeae. Effects of oxidant stress and exposure to human neutrophils.

    Science.gov (United States)

    Zheng, H Y; Hassett, D J; Bean, K; Cohen, M S

    1992-09-01

    We studied the effects of oxidant stress on the catalase activity and hydrogen peroxide sensitivity of Neisseria gonorrhoeae. N. gonorrhoeae is an obligate pathogen of man that evokes a remarkable but ineffective neutrophil response. Gonococci make no superoxide dismutase but express high catalase activity. Gonococcal catalase activity increased threefold when organisms were subjected to 1.0 mM hydrogen peroxide. This increase in catalase activity was marked by a parallel increase in protein concentration recognized by a rabbit polyclonal antibody raised against the purified gonococcal enzyme. Catalase was primarily localized to the gonococcal cytoplasm in the presence or absence of stress; only a single isoenzyme of catalase could be identified. Exposure of gonococci to neutrophil-derived oxidants was accomplished by stimulating neutrophils with phorbol myristate acetate or by using gonococcal Opa variants that interacted with neutrophils with different degrees of efficiency. Gonococci exposed to neutrophils demonstrated a twofold increase in catalase activity in spite of some reduction in viability. Exposure of gonococci to 1.0 mM hydrogen peroxide made the organisms significantly more resistant to higher concentrations of hydrogen peroxide and to neutrophils than control organisms. These results suggest that catalase is an important defense for N. gonorrhoeae during attack by human neutrophils. The rapid response of this enzyme to hydrogen peroxide should be taken into consideration in studies designed to evaluate the interaction between neutrophils and gonococci. PMID:1522209

  14. The utilization of some iron and zinc compounds as regulators of catalase activity at Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Efremova, N.

    2013-11-01

    Full Text Available The main aim of this study was to examine the impact of some zinc and iron compounds as oxidative stress factors on catalase activity, which is known to be important defense system of microorganisms to metal stress. For the investigation was used baker's yeast strain - Saccharomyces cerevisiae CNMN-Y-11 previously selected as a source of protein and catalase. The obtained results have revealed that compounds of iron and zinc with citrate and acetate contributes to the accumulation of yeast biomass and have beneficial effect on the catalase activity at selected yeast strain. The maximum increase of catalase activity in yeast biomass was established in case of iron and zinc citrate supplementation to the nutritive medium in optimal concentration of 15.0 mg/l. Results of the present study could be used for the elaboration of new procedures of catalase obtaining by directed synthesis with the utilization of selected metal compounds.

  15. Catalase activity in the soil of the wood biogeocenoses in the Samara-river region

    Directory of Open Access Journals (Sweden)

    A. F. Kulik

    2009-11-01

    Full Text Available Research of catalase activity changes in connection with the free-radical oxidation is soil of natural and artificial ecosystems is conducted. The catalase is a plants’ enzyme of antioxidative protection. The catalase activity is a marker of variety and improvement of soils. It is important for the problems solutions in applied soil science. The aberrations of catalase, peroxidase and polyphenol oxidase activities characterise not only the metabolizing of plants, microorganisms and soils, but the level of the environmental pollution. The general activity of enzymatic systems allows ascertaining their role in the forming of biota components’ resistance to the exogenous influence. The seasonal dynamics of the soils’ catalase activity subject to the type of a biogeocenosis is disclosed.

  16. Enhanced stability of catalase covalently immobilized on functionalized titania submicrospheres.

    Science.gov (United States)

    Wu, Hong; Liang, Yanpeng; Shi, Jiafu; Wang, Xiaoli; Yang, Dong; Jiang, Zhongyi

    2013-04-01

    In this study, a novel approach combing the chelation and covalent binding was explored for facile and efficient enzyme immobilization. The unique capability of titania to chelate with catecholic derivatives at ambient conditions was utilized for titania surface functionalization. The functionalized titania was then used for enzyme immobilization. Titania submicrospheres (500-600 nm) were synthesized by a modified sol-gel method and functionalized with carboxylic acid groups through a facile chelation method by using 3-(3,4-dihydroxyphenyl) propionic acid as the chelating agent. Then, catalase (CAT) was covalently immobilized on these functionalized titania submicrospheres through 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. The immobilized CAT retained 65% of its free form activity with a loading capacity of 100-150 mg/g titania. The pH stability, thermostability, recycling stability and storage stability of the immobilized CAT were evaluated. A remarkable enhancement in enzyme stability was achieved. The immobilized CAT retained 90% and 76% of its initial activity after 10 and 16 successive cycles of decomposition of hydrogen peroxide, respectively. Both the Km and the Vmax values of the immobilized CAT (27.4 mM, 13.36 mM/min) were close to those of the free CAT (25.7 mM, 13.46 mM/min). PMID:23827593

  17. A Review on Direct Electrochemistry of Catalase for Electrochemical Sensors

    Directory of Open Access Journals (Sweden)

    Periasamy Arun Prakash

    2009-03-01

    Full Text Available Catalase (CAT is a heme enzyme with a Fe(III/II prosthetic group at its redox centre. CAT is present in almost all aerobic living organisms, where it catalyzes the disproportionation of H2O2 into oxygen and water without forming free radicals. In order to study this catalytic mechanism in detail, the direct electrochemistry of CAT has been investigated at various modified electrode surfaces with and without nanomaterials. The results show that CAT immobilized on nanomaterial modified electrodes shows excellent catalytic activity, high sensitivity and the lowest detection limit for H2O2 determination. In the presence of nanomaterials, the direct electron transfer between the heme group of the enzyme and the electrode surface improved significantly. Moreover, the immobilized CAT is highly biocompatible and remains extremely stable within the nanomaterial matrices. This review discusses about the versatile approaches carried out in CAT immobilization for direct electrochemistry and electrochemical sensor development aimed as efficient H2O2 determination. The benefits of immobilizing CAT in nanomaterial matrices have also been highlighted.

  18. N-acetyltransferase Mpr1 confers ethanol tolerance on Saccharomyces cerevisiae by reducing reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Du, Xiaoyi [Fukui Prefectural Univ., Fukui (Japan). Dept. of Bioscience; Takagi, Hiroshi [Nara Inst. of Science and Technology, Ikoma, Nara (Japan). Graduate School of Biological Sciences

    2007-07-15

    N-Acetyltransferase Mpr1 of Saccharomyces cerevisiae can reduce intracellular oxidation levels and protect yeast cells under oxidative stress, including H{sub 2}O{sub 2}, heat-shock, or freeze-thaw treatment. Unlike many antioxidant enzyme genes induced in response to oxidative stress, the MPR1 gene seems to be constitutively expressed in yeast cells. Based on a recent report that ethanol toxicity is correlated with the production of reactive oxygen species (ROS), we examined here the role of Mpr1 under ethanol stress conditions. The null mutant of the MPR1 and MPR2 genes showed hypersensitivity to ethanol stress, and the expression of the MPR1 gene conferred stress tolerance. We also found that yeast cells exhibited increased ROS levels during exposure to ethanol stress, and that Mpr1 protects yeast cells from ethanol stress by reducing intracellular ROS levels. When the MPR1 gene was overexpressed in antioxidant enzyme-deficient mutants, increased resistance to H{sub 2}O{sub 2} or heat shock was observed in cells lacking the CTA1, CTT1, or GPX1 gene encoding catalase A, catalase T, or glutathione peroxidase, respectively. These results suggest that Mpr1 might compensate the function of enzymes that detoxify H{sub 2}O{sub 2}. Hence, Mpr1 has promising potential for the breeding of novel ethanol-tolerant yeast strains. (orig.)

  19. PaCATB, a secreted catalase protecting Podospora anserina against exogenous oxidative stress

    DEFF Research Database (Denmark)

    Zintel, Sandra; Bernhardt, Dominik; Rogowska-Wrzesinska, Adelina;

    2011-01-01

    . Genetic modulation of the abundance of PaCATB identified differential effects on the phenotype of the corresponding strains. Deletion of PaCatB resulted in decreased resistance, over-expression in increased resistance against hydrogen peroxide. While the lifespan of the genetically modified strains was...... found to be unaffected under standard growth conditions, increased exogenous hydrogen peroxide stress in the growth medium markedly reduced the lifespan of the PaCatB deletion strain but extended the lifespan of PaCatB over-expressors. Overall our data identify a component of the secretome of P...

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

    Science.gov (United States)

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

    2004-08-01

    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 catalase from the shrimp Penaeus (Litopenaeus) vannamei was sequenced and the mRNA was detected by RT-PCR in selected tissues. Catalase was detected in hepatopancreas crude extracts by Western blot analysis with anti-human catalase polyclonal antibodies. The nucleotide sequence is 1692 bp long, including a 72-bp 5'-UTR, a coding sequence of 1515 bp and a 104-bp 3'-UTR. The deduced amino acid sequence corresponds to 505 amino acids with high identity to invertebrate, vertebrate and even bacterial catalases and contains the catalytic residues His71, Asn144, and Tyr354. The predicted protein has a calculated molecular mass of 57 kDa; which coincides with the size of the subunit (approximately 55 kDa) and the tetrameric protein (approximately 230 kDa) detected in hepatopancreas extracts under native conditions. Catalase mRNA level was higher in hepatopancreas, followed by gills and was not detected in muscle. PMID:15325332

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

    Energy Technology Data Exchange (ETDEWEB)

    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); Lim, Soon Sung [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); Kwon, Hyeok Yil [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); Cho, Sung-Woo [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); 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.

  2. A superoxide dismutase/catalase mimetic nanomedicine for targeted therapy of inflammatory bowel disease.

    Science.gov (United States)

    Zhang, Qixiong; Tao, Hui; Lin, Yongyao; Hu, Ying; An, Huijie; Zhang, Dinglin; Feng, Shibin; Hu, Houyuan; Wang, Ruibing; Li, Xiaohui; Zhang, Jianxiang

    2016-10-01

    Oxidative stress, resulting from excessive generation of reactive oxygen species (ROS), plays a pivotal role in the initiation and progression of inflammatory bowel disease (IBD). To develop an efficacious and safe nanotherapy against IBD, we designed and developed a superoxide dismutase/catalase mimetic nanomedicine comprising a hydrogen peroxide-eliminating nanomatrix and a free radical scavenger Tempol (Tpl). To this end, an oxidation-responsive β-cyclodextrin material (OxbCD) was synthesized, and a Tpl-loaded OxbCD nanoparticle (Tpl/OxbCD NP) was produced. Hydrolysis of OxbCD NP could be triggered by hydrogen peroxide, leading to on-demand release of loaded Tpl molecules from Tpl/OxbCD NP. OxbCD NP was able to efficiently accumulate in the inflamed colon in mice, thereby dramatically reducing nonspecific distribution after oral delivery. In three mouse colitis models, oral administration of Tpl/OxbCD NP notably mitigated manifestations relevant to colitis, and significantly suppressed expression of proinflammatory mediators, with the efficacy superior over free Tpl or a control nanomedicine based on poly(lactide-co-glycolide) (PLGA). Accordingly, by scavenging multiple components of ROS, Tpl/OxbCD NP may effectively reduce ulcerative colitis in mice, and it can be intensively developed as a translational nanomedicine for the management of IBD and other inflammatory diseases. PMID:27525680

  3. The catalase gene differentiates between some strains of Staphylococcus aureus ssp. anaerobius

    OpenAIRE

    Musa, N. O.; Eltom, K.; Gessler, F.; H. Böhnel; Babiker, A.; Sanousi, S. M.

    2010-01-01

    Staphylococcus aureus ssp anaerobius strain S10 was isolated from an outbreak of sheep abscess disease. Sequence of the catalase gene of this strain showed 99 % identity to the catalase gene (katB) sequence of the reference strain (S. aureus ssp. anaerobius strain MVF213) with mismatching of three base pairs. An important substitution located 1036 nucleotides upstream of the initiation codon from “C” in katB to “T” in the catalase gene of strain S10 originated a stop codon. The de...

  4. Recovery of a catalase-negative Staphylococcus epidermidis strain in blood and urine cultures from a patient with pyelonephritis.

    Science.gov (United States)

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

    2011-11-01

    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

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

    Science.gov (United States)

    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

  6. Cytoplasmic expression of recombinant interleukin-2 and interleukin-4 proteins results in hydrogen peroxide accumulation and reduction in catalase activity in Escherichia coli

    Directory of Open Access Journals (Sweden)

    M.S Hejazi

    2009-08-01

    Full Text Available Background and the purpose of the study: The Reactive oxygen species (ROS is induced in the cells following various stresses but the effect of recombinant protein expression on ROS generation has not been studied yet. In this study, H2O2 concentration and catalase activity variations and their correlation with cell growth following cytoplasmic expression of human interleukin-2 (hIL-2 and mouse interleukin-4 (mIL-4 in Escherichia coli were investigated. Additionally, the effect of recombinant protein expression under different conditions was compared to the effect of foreign DNA introduction on these factors. Methods: Plasmids pEThIL-2 and pETmIL-4 were used for expression of human interleukin-2 (hIL-2 and mouse interleukin-4 (mIL-4 inside the cytoplasm of the cells. Having confirmed protein expression using SDS-PAGE analysis and ELISA assay, H2O2 concentration and catalase activity were measured at various ODs. Results and major conclusion: Empty vector introduction increased significantly H2O2 concentration of the cells. However, H2O2 concentration in hIL-2 and mIL-4 expressing cells was significantly higher than its concentration in empty vector transformed cells. Catalase activity was reduced in foreign DNA introduced cells. It was more lowered following expression of recombinant proteins. Results of this study revealed the relationship between foreign DNA introduction and protein expression with H2O2 elevation and catalase activity reduction. There was also correlation between H2O2 elevation and reduction in catalase activity with the cell growth depression.

  7. Action of ionizing radiation on catalase synthesis in the rat liver

    International Nuclear Information System (INIS)

    3-amino-1,2,4-triazole was used to study the effect of total-body X-ray irradiation on the rates of catalase synthesis and breakdown in rat liver. It was found that in the interval between hour 22 and hour 144 of radiation sickness, the average rate of catalase synthesis in the liver was 2.6 times lower in rats that received a dose of 800 rads than in control rats

  8. katGI and katGII encode two different catalases-peroxidases in Mycobacterium fortuitum.

    OpenAIRE

    Menéndez, M C; Ainsa, J A; Martín, C.; García, M.J.

    1997-01-01

    It has been suggested that catalase-peroxidase plays an important role in several aspects of mycobacterial metabolism and is a virulence factor in the main pathogenic mycobacteria. In this investigation, we studied genes encoding for this protein in the fast-growing opportunistic pathogen Mycobacterium fortuitum. Nucleotide sequences of two different catalase-peroxidase genes (katGI and katGII) of M. fortuitum are described. They show only 64% homology at the nucleotide level and 55% identity...

  9. The utilization of some iron and zinc compounds as regulators of catalase activity at Saccharomyces cerevisiae

    OpenAIRE

    Efremova, N.; E. Molodoi; Usatîi, A.; Fulga, L.

    2013-01-01

    The main aim of this study was to examine the impact of some zinc and iron compounds as oxidative stress factors on catalase activity, which is known to be important defense system of microorganisms to metal stress. For the investigation was used baker's yeast strain - Saccharomyces cerevisiae CNMN-Y-11 previously selected as a source of protein and catalase. The obtained results have revealed that compounds of iron and zinc with citrate and acetate contributes to the accumulation of yeast bi...

  10. INVOLVEMENT OF CATALASE IN SACCHAROMYCES CEREVISIAE HORMETIC RESPONSE TO HYDROGEN PEROXIDE

    Directory of Open Access Journals (Sweden)

    Ruslana Vasylkovska

    2015-05-01

    Full Text Available In this study, we investigated the relationship between catalase activity and H2O2-induced hormetic response in budding yeast S. cerevisiae. In general, our data suggest that: (i hydrogen peroxide induces hormesis in a concentration- and time-dependent manner; and (ii the effect of hydrogen peroxide on yeast colony growth positively correlates with the activity of catalase that suggests the enzyme involvement in overall H2O2-induced stress response and hormetic response in yeast.

  11. Peroxisomal Catalase in the Methylotrophic Yeast Candida boidinii: Transport Efficiency and Metabolic Significance

    OpenAIRE

    Horiguchi, Hirofumi; Yurimoto, Hiroya; Goh, Toh-Kheng; Nakagawa, Tomoyuki; Kato, Nobuo; Sakai, Yasuyoshi

    2001-01-01

    In this study we cloned CTA1, the gene encoding peroxisomal catalase, from the methylotrophic yeast Candida boidinii and studied targeting of the gene product, Cta1p, into peroxisomes by using green fluorescent protein (GFP) fusion proteins. A strain from which CTA1 was deleted (cta1Δ strain) showed marked growth inhibition when it was grown on the peroxisome-inducing carbon sources methanol, oleate, and d-alanine, indicating that peroxisomal catalase plays an important nonspecific role in pe...

  12. INVOLVEMENT OF CATALASE IN SACCHAROMYCES CEREVISIAE HORMETIC RESPONSE TO HYDROGEN PEROXIDE

    OpenAIRE

    Ruslana Vasylkovska; Nadia Burdylyuk; Halyna Semchyshyn

    2015-01-01

    In this study, we investigated the relationship between catalase activity and H2O2-induced hormetic response in budding yeast S. cerevisiae. In general, our data suggest that: (i) hydrogen peroxide induces hormesis in a concentration- and time-dependent manner; and (ii) the effect of hydrogen peroxide on yeast colony growth positively correlates with the activity of catalase that suggests the enzyme involvement in overall H2O2-induced stress response and hormetic response in yeast.

  13. Posttranscriptional Control Mediates Cell Type-Specific Localization of Catalase A during Aspergillus nidulans Development

    OpenAIRE

    Navarro, Rosa E.; Aguirre, Jesús

    1998-01-01

    Two differentially regulated catalase genes have been identified in the fungus Aspergillus nidulans. The catA gene belongs to a class whose transcripts are specifically induced during asexual sporulation (conidiation) and encodes a catalase accumulated in conidia. Using a developmental mutant affected in the brlA gene, which is unable to form conidia but capable of producing sexual spores (ascospores), we demonstrated that the catA mRNA accumulated during induction of conidiation but did not ...

  14. Interference of a commercial catalase preparation in laccase and peroxidase activities

    Directory of Open Access Journals (Sweden)

    Nara Ballaminut

    2009-10-01

    Full Text Available The influence of commercial catalase preparations (fungal and bovine origin on laccase and peroxidase activity assays was evaluated using enzymatic extracts obtained from several basidiomycetes grown under different culture conditions. No hydrogen peroxide was detected in the extracts. Inhibition of laccase activity by 40 to 80% was related to the catalase source. In addition, oxidation of the substrate (ABTS by fungal catalase in the absence of the enzymatic extract from basidiomycetes was observed. The results demonstrated the need for the evaluation of interference of the commercial catalase preparation when its use was required in the reaction mixture.A influência da preparação comercial de catalase (origem fúngica e bovina nos ensaios de atividade absence and presence of a fungal or bovine de lacase e de peroxidases foi avaliada empregando-se extratos enzimáticos obtidos do crescimento de diversos basidiomicetos em diferentes condições de cultivo. Não foi detectado H2O2 nos extratos. Inibição de 40 a 80% da atividade de lacase foi relacionada à fonte de catalase. Além disso, foi observada oxidação do substrato (ABTS pela catalase fúngica, na ausência de extrato enzimático do basidiomiceto. Os resultados evidenciaram a necessidade de se proceder a uma avaliação da interferência da preparação comercial de catalase, quando o seu uso se fizer necessário na mistura reacional.

  15. ADAM12 overexpression does not improve outcome in mice with laminin alpha2-deficient muscular dystrophy

    DEFF Research Database (Denmark)

    Guo, Ling T; Shelton, G Diane; Wewer, Ulla M;

    2005-01-01

    We have recently shown that overexpression of ADAM12 results in increased muscle regeneration and significantly reduced pathology in mdx, dystrophin deficient mice. In the present study, we tested the effect of overexpressing ADAM12 in dy(W) laminin-deficient mice. dy mice have a very severe clin...

  16. Changes in the TBARs content and superoxide dismutase, catalase and glutathione peroxidase activities in the lymphoid organs and skeletal muscles of adrenodemedullated rats

    OpenAIRE

    Pereira B.; Costa-Rosa L.F.B.P.; Bechara E.J.H.; Newsholme P.; Curi R.

    1998-01-01

    Thiobarbituric acid reactant substances (TBARs) content, and the activities of glucose-6-phosphate dehydrogenase (G6PDh), citrate synthase (CS), Cu/Zn- and Mn-superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) were measured in the lymphoid organs (thymus, spleen, and mesenteric lymph nodes (MLN)) and skeletal muscles (gastrocnemius and soleus) of adrenodemedullated (ADM) rats. The results were compared with those obtained for sham-operated rats. TBARs content was reduced b...

  17. Effects of Saponin from Solanum anguivi Lam. Fruit on Heart and Kidney Superoxide Dismutase, Catalase and Malondialdehyde in Rat

    Directory of Open Access Journals (Sweden)

    O.O. Elekofehinti

    2012-07-01

    Full Text Available Reactive Oxygen Species (ROS are generated via normal metabolic processes or as the products of exogenous insults. They are capable of damaging essential biomolecules and accelerating cancer, cardiovascular diseases and neurodegenerative diseases. In this study, the effect saponin from Solanum anguivi (SAS fruits on Superoxide Dismutase (SOD, catalase (CAT and Lipid Peroxidation (LPO in the homogenates of the hearts and kidney was evaluated. Thirty six male Wister rats of average weight125±12 g were divided into six groups of six animals each. Five treated groups received a daily dose of saponin at 20 40 60 80 and 100 mg/kg, respectively, while distilled water was administered to the control group for 3 weeks. Solanum anguivi saponin significantly increased (p<0.05 both catalase and SOD activities in the heart, There was also corresponding increase in activities of both enzymes in the kidney but was not significant. MDA concentration was reduced significantly (p<0.05 in both tissues. SAS exhibit both antioxidant and antiperoxidative properties. Saponin from Solanum anguivi could therefore be employed as sources of natural antioxidant boosters and for the treatment of some oxidative stress disorders in which free radicals are implicated.

  18. Modulatory effect of pineapple peel extract on lipid peroxidation,catalase activity and hepatic biomarker levels in blood plasma of alcoholinduced oxidative stressed rats

    Institute of Scientific and Technical Information of China (English)

    Okafor; OY; Erukainure; OL; Ajiboye; JA; Adejobi; RO; Owolabi; FO; Kosoko; SB

    2011-01-01

    Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.

  19. Purification and characterization of oxygen-inducible haem catalase from oxygen-tolerant Bifidobacterium asteroides.

    Science.gov (United States)

    Hayashi, Kyohei; Maekawa, Itaru; Tanaka, Kunifusa; Ijyuin, Susumu; Shiwa, Yu; Suzuki, Ippei; Niimura, Youichi; Kawasaki, Shinji

    2013-01-01

    Bifidobacterium asteroides, originally isolated from honeybee intestine, was found to grow under 20% O(2) conditions in liquid shaking culture using MRS broth. Catalase activity was detected only in cells that were exposed to O(2) and grown in medium containing a haem source, and these cells showed higher viability on exposure to H(2)O(2). Passage through multiple column chromatography steps enabled purification of the active protein, which was identified as a homologue of haem catalase on the basis of its N-terminal sequence. The enzyme is a homodimer composed of a subunit with a molecular mass of 55 kDa, and the absorption spectrum shows the typical profile of bacterial haem catalase. A gene encoding haem catalase, which has an amino acid sequence coinciding with the N-terminal amino acid sequence of the purified protein, was found in the draft genome sequence data of B. asteroides. Expression of the katA gene was induced in response to O(2) exposure. The haem catalase from B. asteroides shows about 70-80% identity with those from lactobacilli and other lactic acid bacteria, and no homologues were found in other bifidobacterial genomes. PMID:23154971

  20. Ectopic catalase expression in mitochondria by adeno-associated virus enhances exercise performance in mice.

    Directory of Open Access Journals (Sweden)

    Dejia Li

    Full Text Available Oxidative stress is thought to compromise muscle contractility. However, administration of generic antioxidants has failed to convincingly improve performance during exhaustive exercise. One possible explanation may relate to the inability of the supplemented antioxidants to effectively eliminate excessive free radicals at the site of generation. Here, we tested whether delivering catalase to the mitochondria, a site of free radical production in contracting muscle, could improve treadmill performance in C57Bl/6 mice. Recombinant adeno-associated virus serotype-9 (AV.RSV.MCAT was generated to express a mitochondria-targeted catalase gene. AV.RSV.MCAT was delivered to newborn C57Bl/6 mouse circulation at the dose of 10(12 vector genome particles per mouse. Three months later, we observed a approximately 2 to 10-fold increase of catalase protein and activity in skeletal muscle and the heart. Subcellular fractionation western blot and double immunofluorescence staining confirmed ectopic catalase expression in the mitochondria. Compared with untreated control mice, absolute running distance and body weight normalized running distance were significantly improved in AV.RSV.MCAT infected mice during exhaustive treadmill running. Interestingly, ex vivo contractility of the extensor digitorum longus muscle was not altered. Taken together, we have demonstrated that forced catalase expression in the mitochondria enhances exercise performance. Our result provides a framework for further elucidating the underlying mechanism. It also raises the hope of applying similar strategies to remove excessive, pathogenic free radicals in certain muscle diseases (such as Duchenne muscular dystrophy and ameliorate muscle disease.

  1. Arrhenius activation energy of damage to catalase during spray-drying.

    Science.gov (United States)

    Schaefer, Joachim; Lee, Geoffrey

    2015-07-15

    The inactivation of catalase during spray-drying over a range of outlet gas temperatures could be closely represented by the Arrhenius equation. From this an activation energy for damage to the catalase could be calculated. The close fit to Arrhenius suggests that the thermally-induced part of inactivation of the catalase during the complex drying and particle-formation processes takes place at constant temperature. These processes are rapid compared with the residence time of the powder in the collecting vessel of the cyclone where dried catalase is exposed to a constant temperature equal to approximately the drying gas outlet temperature. A lower activation energy after spray drying with the ultrasonic nozzle was found than with the 2-fluid nozzle under otherwise identical spray drying conditions. It is feasible that the ultrasonic nozzle when mounted in the lid of the spray dryer heats up toward the drying gas inlet temperature much more that the air-cooled 2-fluid nozzle. Calculation of the Arrhenius activation energy also showed how the stabilizing efficacy of trehalose and mannitol on the catalase varies in strength across the range of drying gas inlet and outlet temperatures examined. PMID:25940040

  2. The catalase gene differentiates between some strains of Staphylococcus aureus ssp. anaerobius.

    Science.gov (United States)

    Musa, N O; Eltom, K; Gessler, F; Böhnel, H; Babiker, A; El Sanousi, S M

    2010-05-01

    Staphylococcus aureus ssp anaerobius strain S10 was isolated from an outbreak of sheep abscess disease. Sequence of the catalase gene of this strain showed 99% identity to the catalase gene (katB) sequence of the reference strain (S. aureus ssp. anaerobius strain MVF213) with mismatching of three base pairs. An important substitution located 1036 nucleotides upstream of the initiation codon from "C" in katB to "T" in the catalase gene of strain S10 originated a stop codon. The deduced protein (345 amino acids) is 105 amino acids shorter than that of katB. Partial sequence of the catalase gene of other 8 local isolates in addition to another reference strain (DSM 20714/ATCC 35844) revealed the same mutations in all local (African) strains, whereas the sequence of the reference (European) strain was typical to that of katB. Sequence of the catalase gene of S. aureus ssp. anaerobius strain S10 was deposited in GenBank under accession no. EU281993. PMID:20526831

  3. Revolutionizing membrane protein overexpression in bacteria

    OpenAIRE

    Schlegel, Susan; Klepsch, Mirjam; Gialama, Dimitra; Wickström, David; Slotboom, Dirk Jan; De Gier, Jan‐Willem

    2010-01-01

    Summary The bacterium Escherichia coli is the most widely used expression host for overexpression trials of membrane proteins. Usually, different strains, culture conditions and expression regimes are screened for to identify the optimal overexpression strategy. However, yields are often not satisfactory, especially for eukaryotic membrane proteins. This has initiated a revolution of membrane protein overexpression in bacteria. Recent studies have shown that it is feasible to (i) engineer or ...

  4. NUCKS overexpression in breast cancer

    Directory of Open Access Journals (Sweden)

    Kittas Christos

    2009-08-01

    Full Text Available Abstract Background NUCKS (Nuclear, Casein Kinase and Cyclin-dependent Kinase Substrate is a nuclear, DNA-binding and highly phosphorylated protein. A number of reports show that NUCKS is highly expressed on the level of mRNA in several human cancers, including breast cancer. In this work, NUCKS expression on both RNA and protein levels was studied in breast tissue biopsies consisted of invasive carcinomas, intraductal proliferative lesions, benign epithelial proliferations and fibroadenomas, as well as in primary cultures derived from the above biopsies. Specifically, in order to evaluate the level of NUCKS protein in correlation with the histopathological features of breast disease, immunohistochemistry was employed on paraffin sections of breast biopsies of the above types. In addition, NUCKS expression was studied by means of Reverse Transcription PCR (RT-PCR, real-time PCR (qRT-PCR and Western immunoblot analyses in the primary cell cultures developed from the same biopsies. Results The immunohistochemical Results showed intense NUCKS staining mostly in grade I and II breast carcinomas compared to normal tissues. Furthermore, NUCKS was moderate expressed in benign epithelial proliferations, such as adenosis and sclerosing adenosis, and highly expressed in intraductal lesions, specifically in ductal carcinomas in situ (DCIS. It is worth noting that all the fibroadenoma tissues examined were negative for NUCKS staining. RT-PCR and qRT-PCR showed an increase of NUCKS expression in cells derived from primary cultures of proliferative lesions and cancerous tissues compared to the ones derived from normal breast tissues and fibroadenomas. This increase was also confirmed by Western immunoblot analysis. Although NUCKS is a cell cycle related protein, its expression does not correlate with Ki67 expression, neither in tissue sections nor in primary cell cultures. Conclusion The results show overexpression of the NUCKS protein in a number of non

  5. Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress

    OpenAIRE

    Klingelhoeffer Christoph; Kämmerer Ulrike; Koospal Monika; Mühling Bettina; Schneider Manuela; Kapp Michaela; Kübler Alexander; Germer Christoph-Thomas; Otto Christoph

    2012-01-01

    Abstract Background Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. ...

  6. Layer-by-layer assembled multilayers using catalase-encapsulated gold nanoparticles

    International Nuclear Information System (INIS)

    We introduce a novel and versatile approach for the preparation of multilayers, based on catalase-encapsulated gold nanoparticles (CAT-AuNP), allowing electrostatic charge reversal and structural transformation through pH adjustment. CAT-AuNP, which are synthesized directly from CAT stabilizer, can be electrostatically assembled with anionic and cationic PEs as a result of the charge reversal of the catalase stabilizers through pH control. In particular, at pH 5.2, near the pI of catalase, dispersed CAT-AuNP are structurally transformed into colloidal or network CAT-AuNP nanocomposites. Furthermore, we demonstrate that the layer-by-layer assembled multilayers composed of PEs and CAT-AuNP induce an effective electron transfer between CAT and the electrode as well as a high loading of CAT and AuNP, and resultantly exhibit a highly catalytic activity toward H2O2.

  7. The mycobacterial LysR-type regulator OxyS responds to oxidative stress and negatively regulates expression of the catalase-peroxidase gene.

    Directory of Open Access Journals (Sweden)

    Yuqing Li

    Full Text Available 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-N(11-A motif for OxyS binding was successfully characterized in the core binding site. Interestingly, the DNA-binding activity of OxyS was inhibited by H(2O(2, 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 H(2O(2. 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.

  8. Transgenic Mouse Model for Reducing Oxidative Damage in Bone

    Science.gov (United States)

    Schreurs, A.-S.; Torres, S.; Truong, T.; Kumar, A.; Alwood, J. S.; Limoli, C. L.; Globus, R. K.

    2014-01-01

    Exposure to musculoskeletal disuse and radiation result in bone loss; we hypothesized that these catabolic treatments cause excess reactive oxygen species (ROS), and thereby alter the tight balance between bone resorption by osteoclasts and bone formation by osteoblasts, culminating in bone loss. To test this, we used transgenic mice which over-express the human gene for catalase, targeted to mitochondria (MCAT). Catalase is an anti-oxidant that converts the ROS hydrogen peroxide into water and oxygen. MCAT mice were shown previously to display reduced mitochondrial oxidative stress and radiosensitivity of the CNS compared to wild type controls (WT). As expected, MCAT mice expressed the transgene in skeletal tissue, and in marrow-derived osteoblasts and osteoclast precursors cultured ex vivo, and also showed greater catalase activity compared to wildtype (WT) mice (3-6 fold). Colony expansion in marrow cells cultured under osteoblastogenic conditions was 2-fold greater in the MCAT mice compared to WT mice, while the extent of mineralization was unaffected. MCAT mice had slightly longer tibiae than WT mice (2%, P less than 0.01), although cortical bone area was slightly lower in MCAT mice than WT mice (10%, p=0.09). To challenge the skeletal system, mice were treated by exposure to combined disuse (2 wk Hindlimb Unloading) and total body irradiation Cs(137) (2 Gy, 0.8 Gy/min), then bone parameters were analyzed by 2-factor ANOVA to detect possible interaction effects. Treatment caused a 2-fold increase (p=0.015) in malondialdehyde levels of bone tissue (ELISA) in WT mice, but had no effect in MCAT mice. These findings indicate that the transgene conferred protection from oxidative damage caused by treatment. Unexpected differences between WT and MCAT mice emerged in skeletal responses to treatment.. In WT mice, treatment did not alter osteoblastogenesis, cortical bone area, moment of inertia, or bone perimeter, whereas in MCAT mice, treatment increased these

  9. Complete nucleotide sequence of cDNA and deduced amino acid sequence of rat liver catalase.

    OpenAIRE

    Furuta, S.; Hayashi, H; Hijikata, M; Miyazawa, S.; Osumi, T; Hashimoto, T.

    1986-01-01

    We have isolated five cDNA clones for rat liver catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6). These clones overlapped with each other and covered the entire length of the mRNA, which had been estimated to be 2.4 kilobases long by blot hybridization analysis of electrophoretically fractionated RNA. Nucleotide sequencing was carried out on these five clones and the composite nucleotide sequence of catalase cDNA was determined. The 5' noncoding region contained 83 b...

  10. Translational control of catalase synthesis by hemin in the yeast Saccharomyces cerevisiae

    OpenAIRE

    Hamilton, Barbara; Hofbauer, Reinhold; Ruis, Helmut

    1982-01-01

    mRNA-dependent cell-free protein synthesis systems were prepared from a heme-deficient ole3 mutant of the yeast Saccharomyces cerevisiae grown either in the absence or in the presence of the heme precursor δ-aminolevulinate. When supplemented with total yeast mRNA, the two systems—from heme-deficient and from heme-containing cells—translate most mRNAs with comparable efficiencies. mRNAs coding for the hemoproteins catalase T and catalase A, however, are translated at a low rate by the system ...

  11. Computational study concerning the effect of some pesticides on the Proteus Mirabilis catalase activity

    Science.gov (United States)

    Isvoran, Adriana

    2016-03-01

    Assessment of the effects of the herbicides nicosulfuron and chlorsulfuron and the fungicides difenoconazole and drazoxlone upon catalase produced by soil microorganism Proteus mirabilis is performed using the molecular docking technique. The interactions of pesticides with the enzymes are predicted using SwissDock and PatchDock docking tools. There are correlations for predicted binding energy values for enzyme-pesticide complexes obtained using the two docking tools, all the considered pesticides revealing favorable binding to the enzyme, but only the herbicides bind to the catalytic site. These results suggest the inhibitory potential of chlorsulfuron and nicosulfuron on the catalase activity in soil.

  12. Lack of significant effects of superoxide dismutase and catalase on development of reperfusion arrhythmias.

    Science.gov (United States)

    Hagar, J M; Hale, S L; Ilvento, J P; Kloner, R A

    1991-01-01

    It has been reported that agents having the ability to scavenge oxygen-derived free radicals reduce the severity of ventricular arrhythmias that occur after brief coronary occlusion and reperfusion. Superoxide dismutase plus catalase (SOD + CAT) or placebo was administered in a blinded randomized fashion prior to coronary occlusion in rats (n = 25 each group) undergoing a 5-min left coronary occlusion followed by 15 min of reperfusion. During reperfusion, ventricular tachycardia (VT) developed in 96% of animals in both groups. Reperfusion ventricular fibrillation (VF) developed in 60% of the placebo group vs 56% in the SOD + CAT group (p = 1.0). Irreversible VF occurred in 40% of the placebo group vs 20% in the SOD + CAT group (p = 0.22). Atrioventricular block occurred in 12% of placebo and 4% of SOD + CAT animals (p = 0.61). There were no significant difference between groups in duration of VT (85 +/- 15 s (mean +/- SEM) placebo vs 81 +/- 14 s SOD + CAT, p = 0.81), total duration of VT plus VF (391 +/- 76 s placebo vs 256 +/- 64 SOD + CAT, p = 0.45) or numbers of single ventricular ectopic beats (65 +/- 15 placebo vs 97 +/- 18 SOD + CAT, p = 0.18). Heart rate at reperfusion was slightly higher in control than SOD + CAT animals (340 +/- 33 vs 319 +/- 32, p = 0.02). Risk zone size, determined by Monastral blue injection, was equal in both groups (34 +/- 2% of ventricular mass). The occurrence of reperfusion VF in this model could not be predicted by heart rate at reperfusion (331 +/- 33 VF animlas vs 328 +/- 36 no VF, p = 0.77), or by risk zone size (34 +/- 2%, VF and no VF groups).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1877967

  13. Revolutionizing membrane protein overexpression in bacteria

    NARCIS (Netherlands)

    Schlegel, Susan; Klepsch, Mirjam; Gialama, Dimitra; Wickstrom, David; Slotboom, Dirk Jan; de Gier, Jan-Willem; Wickström, David

    2010-01-01

    The bacterium Escherichia coli is the most widely used expression host for overexpression trials of membrane proteins. Usually, different strains, culture conditions and expression regimes are screened for to identify the optimal overexpression strategy. However, yields are often not satisfactory, e

  14. Perilipin overexpression in mice protects against diet-induced obesity

    OpenAIRE

    Miyoshi, Hideaki; Souza, Sandra C.; Endo, Mikiko; Sawada, Takashi; Perfield, James W.; Shimizu, Chikara; Stancheva, Zlatina; Nagai, So; Strissel, Katherine J.; Yoshioka, Narihito; Obin, Martin S.; Koike, Takao; Greenberg, Andrew S.

    2010-01-01

    Perilipin A is the most abundant phosphoprotein on adipocyte lipid droplets and is essential for lipid storage and lipolysis. Perilipin null mice exhibit diminished adipose tissue, elevated basal lipolysis, reduced catecholamine-stimulated lipolysis, and increased insulin resistance. To understand the physiological consequences of increased perilipin expression in vivo, we generated transgenic mice that overexpressed either human or mouse perilipin using the adipocyte-specific aP2 promoter/en...

  15. Behavioral decline and premature lethality upon pan-neuronal ferritin overexpression in Drosophila infected with a virulent form of Wolbachia.

    OpenAIRE

    FanisMissirlis; StylianosKosmidis; JoseA.Botella; TraceyA.Rouault; EfthimiosM. C.Skoulakis

    2014-01-01

    Iron is required for organismal growth. Therefore, limiting iron availability may be a key part of the host’s innate immune response to various pathogens, for example in Drosophila infected with Zygomycetes. One way the host can transiently reduce iron bioavailability is by ferritin overexpression. To study the effects of neuronal-specific ferritin overexpression on survival and neurodegeneration we generated flies simultaneously over-expressing transgenes for both ferritin subunits in all ne...

  16. Behavioral decline and premature lethality upon pan-neuronal ferritin overexpression in Drosophila infected with a virulent form of Wolbachia

    OpenAIRE

    Kosmidis, Stylianos; Missirlis, Fanis; Botella, Jose A.; Schneuwly, Stephan; Rouault, Tracey A.; Skoulakis, Efthimios M. C.

    2014-01-01

    Iron is required for organismal growth. Therefore, limiting iron availability may be a key part of the host’s innate immune response to various pathogens, for example, in Drosophila infected with Zygomycetes. One way the host can transiently reduce iron bioavailability is by ferritin overexpression. To study the effects of neuronal-specific ferritin overexpression on survival and neurodegeneration we generated flies simultaneously over-expressing transgenes for both ferritin subunits in all n...

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

    Directory of Open Access Journals (Sweden)

    Abrahim Noor

    2012-11-01

    Full Text Available Abstract 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 μg/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

  18. Effects of Radiofrequency Waves on the Catalase Content in Triticum Aestivum

    International Nuclear Information System (INIS)

    Full text: The aim of the present study is to investigate the possible effects on enzyme biosynthesis in Triticum aestivum cariopsydes due to exposure to traveling radiofrequency (RF) waves. Triticum cariopsydes have been exposed to traveling RF waves inside a transverse electromagnetic (TEM) cell fed by a RF Power Generator. The frequency of the exposure field was 400 MHz. The TEM cell was excited with 2W RF power in order to obtain a power density of about 1 mW/cm2. Four sets of Triticum aestivum samples were placed in four Petri dishes. For each set of Triticum cariopsydes there has been chosen a daily exposure duration of 1, 2, 4 and 8 hours respectively. Experimental exposure was carried out for five consecutive days. After the electromagnetic treatment cariopsydes were let to germinate in Petri dishes on porous filter paper support. A couple of days later the catalase assay was performed. In comparison to the control samples, exposed samples revealed modified catalase content, significantly over the error level (five replays of every sample were assayed in identical experimental conditions in order to provide a reliable statistic result). All exposed samples presented higher catalase levels in comparison to the control samples. However, the experimental data do not suggest an evident analytical dependence between the catalase content and the exposure time duration. We presume that exposure to traveling RF waves seems to be a stimulatory factor of the enzyme biosynthesis being able to improve Triticum capacity of enzyme biosynthesis in the described experimental conditions. (author)

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

    Science.gov (United States)

    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...

  20. Effects of peroxide and catalase on near ultraviolet radiation sensitivity in Escherichia coli strains

    International Nuclear Information System (INIS)

    The role of peroxide and catalase on NUV radiation sensitivity was examined in two repair competent E. coli strains, AB1157 and B/r. Exponential phase B/r is considerably more sensitive to NUV radiation than exponential phase AB1157. However, resistance to 5 mmol dm-3 H2O2 was induced in both AB1157 and B/r by pretreating growing cells with 30 μmol dm-3 H2O2. Pretreatment also induced resistance to broad-band NUV radiation in these strains. The addition of catalase to the post-irradiation plating medium increased survival to the same extent as that provided by pretreatment with 30 μmol dm-3 H2O2, in both strains. The NUV radiation sensitivity seen in B/r does not appear to be due to a deficiency in enzymes that scavenge H2O2, as a catalase deficient mutant, E. coli UM1, is more resistant to NUV radiation than B/r. Also, assays for H2O2 scavenging ability show little difference between AB1157 and B/r in this respect. Two hypotheses are put forward to account for the sensitivity of exponential phase B/r. Whilst it is apparent that peroxides and catalase do have a role in NUV radiation damage, it is clear that other factors also influence survival under certain conditions. (author)

  1. Decrease in catalase activity of Folsomia candida fed a Bt rice diet

    International Nuclear Information System (INIS)

    Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding the ecological consequences for organisms inhabiting transgenic Bt-rice plantations. - Highlights: → We examine the effects of Bt-rice on Folsomia candida with laboratory test. → The reproduction of F. candida was decreased by two Bt-rice varieties. → Decreased reproduction caused by the differences of varieties or C/N ratio of rice. → The catalase activity was decreased by Bt-rice Kemingdao. → Some Bt-rice may impose environmental stress on NTOs. - The catalase of the collembolan (Folsomia candida) was decreased when fed Bt-rice, Kemingdao.

  2. Immobilized glucose oxidase--catalase and their deactivation in a differential-bed loop reactor.

    Science.gov (United States)

    Prenosil, J E

    1979-01-01

    Glucose oxidase containing catalase was immobilized with a copolymer of phenylenediamine and glutaraldehyde on pumice and titania carrier to study the enzymatic oxidation of glucose in a differential-bed loop reactor. The reaction rate was found to be first order with respect to the concentration of limiting oxygen substrate, suggesting a strong external mass-transfer resistance for all the flow rates used. The partial pressure of oxygen was varied from 21.3 up to 202.6 kPa. The use of a differential-bed loop reactor for the determination of the active enzyme concentration in the catalyst with negligible internal pore diffusion resistance is shown. Catalyst deactivation was studied, especially with respect to the presence of catalase. It is believed that the hydrogen peroxide formed in the oxidation reaction deactivates catalase first; if an excess of catalase is present, the deactivation of glucose oxidase remains small. The mathematical model subsequently developed adequately describes the experimental results. PMID:427262

  3. Catalase and sodium fluoride mediated rehabilitation of enamel bleached with 37% hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Ruchi Thakur

    2015-01-01

    Full Text Available Background: Bleaching agents bring about a range of unwanted changes in the physical structure of enamel which needs to be restored qualitatively and timely. Catalase being an antioxidant ensures the effective removal of free radicals and improvement in fluoride mediated remineralization from the enamel microstructure which if retained may harm the integrity and affect the hardness of enamel. Materials and Methods: Thirty freshly extracted incisors were sectioned to 6 slabs which were divided into 5 groups: Group A, control; Group B, treatment with 37% hydrogen peroxide (HP; Group C, treatment with 37% HP and catalase, Group D, treatment with 37% HP and 5% sodium fluoride application, Group E, treatment with 37% HP followed by catalase and 5% sodium fluoride. Scanning electron microscope and microhardness analysis were done for all slabs. One-way ANOVA test was applied among different groups. Results: Vicker′s microhardness number (VHN of Group B and C was significantly lower. No significant difference between VHN of Group B and C. VHN of Group D was significantly higher than Group A, B, and C; but significantly lower than Group E. VHN of Group E was significantly higher than any other experimental group. One-way ANOVA revealed a highly significant P value (P = 0.0001 and so Tukey′s post-hoc Test for the group comparisons was employed. Conclusion: Subsequent treatment of bleached enamel with catalase and fluoride varnish separately results in repairing and significantly increasing the microhardness.

  4. Decrease in catalase activity of Folsomia candida fed a Bt rice diet

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yiyang, E-mail: yuanyy@ioz.ac.cn [State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Ke Xin, E-mail: xinke@sibs.ac.cn [Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China); Chen Fajun, E-mail: fajunchen@njau.edu.cn [College of Plant Protection, Department of Entomology, Nanjing Agricultural University, Nanjing 210095 (China); Krogh, Paul Henning, E-mail: phk@dmu.dk [Department of Bioscience, University of Aarhus, P.O. Box 314, Vejlsoevej 25, DK-8600 Silkeborg (Denmark); Ge Feng, E-mail: gef@ioz.ac.cn [State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101 (China)

    2011-12-15

    Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding the ecological consequences for organisms inhabiting transgenic Bt-rice plantations. - Highlights: > We examine the effects of Bt-rice on Folsomia candida with laboratory test. > The reproduction of F. candida was decreased by two Bt-rice varieties. > Decreased reproduction caused by the differences of varieties or C/N ratio of rice. > The catalase activity was decreased by Bt-rice Kemingdao. > Some Bt-rice may impose environmental stress on NTOs. - The catalase of the collembolan (Folsomia candida) was decreased when fed Bt-rice, Kemingdao.

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

    Science.gov (United States)

    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 semen analysis and the Hypoosmotic Viability Test (HVT) were carried out; the samples were then divided into 4 aliquots. The first was untreated as a control; 200 U/ml of superoxide dismutase (SOD) was added to the second, 200 U/ml of 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

  6. Overexpression of the mitochondrial T3 receptor induces skeletal muscle atrophy during aging.

    Directory of Open Access Journals (Sweden)

    François Casas

    Full Text Available In previous studies, we characterized a new hormonal pathway involving a mitochondrial T3 receptor (p43 acting as a mitochondrial transcription factor. In in vitro and in vivo studies, we have shown that p43 increases mitochondrial transcription and mitochondrial biogenesis. In addition, p43 overexpression in skeletal muscle stimulates mitochondrial respiration and induces a shift in metabolic and contractile features of muscle fibers which became more oxidative.Here we have studied the influence of p43 overexpression in skeletal muscle of mice during aging. We report that p43 overexpression initially increased mitochondrial mass. However, after the early rise in mitochondrial DNA occurring at 2 months of age in transgenic mice, we observed a progressive decrease of mitochondrial DNA content which became 2-fold lower at 23 months of age relatively to control animals. Moreover, p43 overexpression induced an oxidative stress characterized by a strong increase of lipid peroxidation and protein oxidation in quadriceps muscle, although antioxidant enzyme activities (catalase and superoxide dismutase were stimulated. In addition, muscle atrophy became detectable at 6 months of age, probably through a stimulation of the ubiquitin proteasome pathway via two muscle-specific ubiquitin ligases E3, Atrogin-1/MAFbx and MuRF1.Taken together, these results demonstrate that a prolonged stimulation of mitochondrial activity induces muscle atrophy. In addition, these data underline the importance of a tight control of p43 expression and suggest that a deregulation of the direct T3 mitochondrial pathway could be one of the parameters involved in the occurrence of sarcopenia.

  7. Comparison of the cytochrome c oxidase inherent catalase side-reaction from Paracoccus denitrificans in the wild type and recombinant form

    OpenAIRE

    Hilbers, Florian

    2015-01-01

    The four subunit (SU) aa3 cytochrome c oxidase (CcO) from Paracoccus denitrificans is one of the terminal enzymes of the respiratory chain. It uses electrons from cytochrome c to reduce molecular oxygen to water. Its binuclear active center, residing in SU I, contains hemeÊa3 and CuB, the latter being liganded by three histidine residues. Apart from its oxygen reductase activity, the protein possesses a peroxidase and a catalase activity. To compare variants and the wild type (WT) protein ...

  8. Overexpression of Bmi1 in Lymphocytes Stimulates Skeletogenesis by Improving the Osteogenic Microenvironment

    Science.gov (United States)

    Zhou, Xichao; Dai, Xiuliang; Wu, Xuan; Ji, Ji; Karaplis, Andrew; Goltzman, David; Yang, Xiangjiao; Miao, Dengshun

    2016-01-01

    To investigate whether overexpression of Bmi1 in lymphocytes can stimulate skeletogenesis by improving the osteogenic microenvironment, we examined the skeletal phenotype of EμBmi1 transgenic mice with overexpression of Bmi1 in lymphocytes. The size of the skeleton, trabecular bone volume and osteoblast number, indices of proliferation and differentiation of bone marrow mesenchymal stem cells (BM-MSCs) were increased significantly, ROS levels were reduced and antioxidative capacity was enhanced in EμBmi1 mice compared to WT mice. In PTHrP1–84 knockin (PthrpKI/KI) mice, the expression levels of Bmi1 are reduced and potentially can mediate the premature osteoporosis observed. We therefore generated a PthrpKI/KI mice overexpressing Bmi1 in lymphocytes and compared them with PthrpKI/KI and WT littermates. Overexpression of Bmi1 in PthrpKI/KI mice resulted in a longer lifespan, increased body weight and improvement in skeletal growth and parameters of osteoblastic bone formation with reduced ROS levels and DNA damage response parameters. Our results demonstrate that overexpression of Bmi1 in lymphocytes can stimulate osteogenesis in vivo and partially rescue defects in skeletal growth and osteogenesis in PthrpKI/KI mice. These studies therefore indicate that overexpression of Bmi1 in lymphocytes can stimulate skeletogenesis by inhibiting oxidative stress and improving the osteogenic microenvironment. PMID:27373231

  9. Endogenous superoxide dismutase and catalase activities and radiation resistance in mouse cell lines

    International Nuclear Information System (INIS)

    The relationship between the endogenous cytoplasmic levels of the enzymes superoxide dismutase and catalase and the inhibition of cell proliferation by γ-radiation has been studied in 11 mouse cell lines. The resistance of these mouse cell lines to radiation was found to vary by over 25-fold. No correlation was found between the cytoplasmic level of CuZn-superoxide dismutase or catalase and the resistance to radiation as measured by extrapolation number (EN), quasi-threshold dose (Dsub(q)), or Dsub(o). None of the cell lines had detectable cytoplasmic Mn-superoxide dismutase. The apparent Ksub(i) of potassium cyanide for mouse CuZn-superoxide dismutase was determined (Ksub(i) = 6.5 μmol dm-3). (author)

  10. Inactivation of catalase monolayers by irradiation with 100 keV electrons

    International Nuclear Information System (INIS)

    A catalase monolayer adsorbed on a layer of arachidic acid deposited on a solid support was irradiated with 100 keV electrons simulating the conditions of electron microscopic imaging. Effective doses were calculated taking into account the angular and energy distribution of backscattered electrons. Enzymatic inactivation was chosen as the criterion for damage and was monitored by a rapid and quantifiable but nevertheless sensitive assay. Dose-response curves revealed that inactivation is a one-hit--multiple-target phenomenon, which is consistent with biochemical evidence for a cooperative function of subunits. The experimentally determined target size coincides fairly well with both calculated cross sections for inelastic interactions based on the atomic composition of catalase and with calculated cross sections for ionizing events based on the chemical bonds involved. This legitimates both types of calculations even for complex biomolecules

  11. A Laboratory Experiment Investigating Different Aspects of Catalase Activity in an Inquiry - Based Approach

    Science.gov (United States)

    Kimbrough, Doris R.; Magoun, Mary Ann; Langfur, Meg

    1997-02-01

    The action of the enzyme catalase on aqueous hydrogen peroxide to generate oxygen gas is a well-established demonstration (1-3). Catalase is typically obtained by aqueous extraction of a potato, and the potato extract is mixed together with 3% hydrogen peroxide. The oxygen that is produced can be collected over water. Variations on the procedure can demonstrate the dependence of catalytic activity on temperature or the presence of inhibitors (1, 2). The University of Colorado at Denver has used a version of this procedure as a laboratory in its second-semester course for nonmajors. Recently, students have been allowed to expand upon the procedures prescribed in the laboratory handout in an open-ended project format. We explored some of these variations in detail, and the results provided here offer ideas, centered around this laboratory, for open-ended projects that can be used in an inquiry-based approach.

  12. Decrease in catalase activity of Folsomia candida fed a Bt rice diet

    DEFF Research Database (Denmark)

    Yuan, Yiyang; Ke, Xin; Chen, Fajun;

    2011-01-01

    Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction...... was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed...... the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding...

  13. Post-irradiation repairing processes of glucose-6-phosphate dehydrogenase and catalase from Hansenula Polymorpha yeast

    International Nuclear Information System (INIS)

    The post-irradiation repairing mechanisms of two Hansenula Polymorpha yeast enzymes, glucose-6-phosphate dehydrogenase and catalase, were studied. The kinetic parameters of the selected enzymes were investigated over one month since the moment of γ-irradiation with different doses in the presence of oxygen. Dose dependent decrease of initial reaction rates was noticed for both enzymes. Small variation of initial reaction rate was recorded for glucose-6-phosphate dehydrogenase over one month, with a decreasing tendency. No significant electrophoretic changes of molecular forms of this enzyme were observed after irradiation. Continuous strong decrease of catalase activity was evident for the first 20 days after irradiation. Partial recovery process of the catalytic activity was revealed by this study. (authors)

  14. Relações da dieta ovo-lácteo-vegetariana com o exercício físico e as enzimas antioxidantes superóxido dismutase e catalase

    Directory of Open Access Journals (Sweden)

    Mírian Rocha Váquez

    2011-06-01

    Full Text Available OBJETIVO: O objetivo deste trabalho foi estudar a influência da dieta ovo-lácteo-vegetariana e do exercício físico extenuante sobre as atividades das enzimas catalase e superóxido dismutase em dez indivíduos masculinos, jovens e saudáveis. MÉTODOS: O controle alimentar aplicou-se por quatro meses. Antes disso, foram recolhidas amostras de sangue em estado basal e cinco minutos após o exercício físico extenuante efetuado em esteira rolante. O mesmo procedimento foi aplicado após o controle alimentar. RESULTADOS: Os resultados mostraram que a dieta ovo-lácteo-vegetariana, em condições de repouso, reduziu de forma significativa a atividade da enzima catalase em 18,98% (pOBJECTIVE: This study aimed to study the influence of an ovolactovegetarian diet and strenuous physical exercise on the activity of the enzymes catalase and superoxide dismutase in 10 young, healthy men whose diet was controlled for four months. METHODS: Blood samples were collected at baseline and after the four-month period, before strenuous exercise and after 5 minutes of strenuous exercise on a treadmill. RESULTS: The results showed that the ovolactovegetarian diet reduced the activity of the enzyme catalase by 18.98% (p<0.05 and increased the activity of the enzyme superoxide dismutase by 77.84% (p<0.001 before strenuous exercise. After strenuous exercise, the ovolactovegetarian diet reduced the activity of the enzyme catalase by 26.11% (p<0.05 and did not affect the activity of the enzyme superoxide dismutase. CONCLUSION: The results indicate that a healthy ovolactovegetarian diet impacts the activity of both enzymes.

  15. Differential activation of catalase expression and activity by PPAR agonists: Implications for astrocyte protection in anti-glioma therapy

    Directory of Open Access Journals (Sweden)

    Nicholas K.H. Khoo

    2013-01-01

    Full Text Available Glioma survival is dismal, in part, due to an imbalance in antioxidant expression and activity. Peroxisome proliferator-activated receptor (PPAR agonists have antineoplastic properties which present new redox-dependent targets for glioma anticancer therapies. Herein, we demonstrate that treatment of primary cultures of normal rat astrocytes with PPAR agonists increased the expression of catalase mRNA protein, and enzymatic activity. In contrast, these same agonists had no effect on catalase expression and activity in malignant rat glioma cells. The increase in steady-state catalase mRNA observed in normal rat astrocytes was due, in part, to de novo mRNA synthesis as opposed to increased catalase mRNA stability. Moreover, pioglitazone-mediated induction of catalase activity in normal rat astrocytes was completely blocked by transfection with a PPARγ-dominant negative plasmid. These data suggest that defects in PPAR-mediated signaling and gene expression may represent a block to normal catalase expression and induction in malignant glioma. The ability of PPAR agonists to differentially increase catalase expression and activity in normal astrocytes but not glioma cells suggests that these compounds might represent novel adjuvant therapeutic agents for the treatment of gliomas.

  16. Effect of a protease inhibitor on the stability of catalase in liver and blood from acatalasemic and normal mice.

    Directory of Open Access Journals (Sweden)

    Suzuki,Kazuhiko

    1991-10-01

    Full Text Available Effects of Gabexate mesilate (GM (([ethyl-4-(6-guanidino hexanoyloxy benzoate] methane sulfonate, a protease inhibitor, on the activities of catalase in liver, erythrocytes and reticulocytes from acatalasemic mice were examined. Preincubation without GM at 37 degrees C for 160 min lowered the catalase activities of liver, erythrocytes and reticulocytes from acatalasemic mice, to 24%, 40% and 10% of the initial levels, respectively. But, preincubation with GM at 37 degrees C for 160 min delayed the rapid decrease in activities of residual catalases in the liver, erythrocytes and reticulocytes of acatalasemic mice to 65%, 93% and 85% of the initial values, respectively. At 20 degrees C or below, no reduction in catalase activity of reticulocytes from acatalasemic mice occurred with or even without GM. At pH 5.0, the decrease in catalase activity of acatalasemic mice was small both in the presence and the absence of GM. In the alkaline range, the reduction in the enzyme activity of the mutant mice without GM was enhanced with increase in pH values up to 8.5. But the presence of GM during preincubation at pH 7.5, retained the catalase activity of acatalasemic mice, to 64% of the activity at pH 6.5. These data suggest that some factors affected by GM, might be responsible for the low stability and activity of catalase in the acatalasemic mice.

  17. Isolation and Purification of Heterotetrameric Catalase from a Desiccation Tolerant Cyanobacterium Lyngbya arboricola

    Directory of Open Access Journals (Sweden)

    Kapoor, Shivali

    2013-02-01

    Full Text Available The desiccation tolerant cyanobacterium Lyngbya arboricola, isolated from bark surfaces of Mangifera indica, possessed up to four stable isoforms of catalase in addition to other antioxidative enzymes, for several years under a dry state. Purification of the two most persistent isoforms of catalase (Cat has been undertaken by employing acetone precipitation, ethanol: chloroform treatment, gel filtration and ion exchange chromatography. The two isoforms of catalase remained almost unchanged on varying matric and osmotic hydration levels of mats of the cyanobacterium. The purification procedures resulted in a 1.3 % yield of purified single isoform (0.22 mg mL-1 protein with 709 Units mg-1 specific activity and a purity index of 0.83. Five millimolar of dithiothreitol (DTT was observed to be pertinent in maintaining the optimum redox state of the enzyme. The purification procedures additionally facilitated the simultaneous elimination and procurement of phycoerythrins (PE and mycosporine-like amino acids (MAA. Each purified isoform gave a single band (~45kDa upon SDS-PAGE and denaturing urea isoelectric focusing (IEF depicted the presence of 2 subunits each of CatA and CatB. The monoisotopic mass and pI value of CatA and CatB as revealed by LC-MS analysis and internal amino acid sequencing was 78.96, 5.89 and 80.77, 5.92, respectively, showing resemblance with CatA of Erysiphe graminis subs. hordei and CatB of Ajellomyces capsulata. The heterotetrameric monofunctional catalase (~320 kDa, due to its stability in the form of resistance to ethanol: chloroform, its thermoalkaliphilic nature and the presence of innumerable hydrophobic amino acid residues (~40%, thus exhibited its potential for biotechnological applications.

  18. Radiation damage of proteins in the solid state: changes of amino acid composition in catalase

    International Nuclear Information System (INIS)

    Catalase has been irradiated with 100 keV electrons under conditions simulating the hazards of electron microscopic imaging. Amino acid analysis reveals a definite pattern of amino acid destruction which is well correlated with the particular chemical structures of amino acid side chains. This pattern appears to be distinctly different from the sensitivity pattern for monoamino acid systems which is ascribed to intramolecular energy transfer and selective attack of liberated radicals

  19. Optimization of permeabilization process of yeast cells for catalase activity using response surface methodology

    OpenAIRE

    Trawczyńska, Ilona; Wójcik, Marek

    2015-01-01

    Biotransformation processes accompanied by whole yeast cells as biocatalyst are a promising area of food industry. Among the chemical sanitizers currently used in food technology, hydrogen peroxide is a very effective microbicidal and bleaching agent. In this paper, permeabilization has been applied to Saccharomyces cerevisiae yeast cells aiming at increased intracellular catalase activity for decomposed H2O2. Ethanol, which is non-toxic, biodegradable and easily available, has been used as p...

  20. High-catalase strains of Mycobacterium kansasii isolated from water in Texas.

    OpenAIRE

    Steadham, J E

    1980-01-01

    Isolation techniques with membrane-filtered potable water samples resulted in the isolation of potentially pathogenic high-catalase strains of Mycobacterium kansasii from 8 of 19 representative outlets in a small central Texas town. Mycobacterium gordonae was isolated from all samples, and Mycobacterium fortuitum was isolated from two samples. Data on chlorine levels are presented along with a possible explanation for the unusually high numbers of mycobacteria in these potable water samples. ...

  1. Extraction of Erythrocyte Enzymes for the Preparation of Polyhemoglobin-catalase-superoxide Dismutase

    OpenAIRE

    Gu, Jingsong; Chang, Thomas Ming Swi

    2009-01-01

    In sustained severe ischemia, reperfusion with oxygen carriers may result in ischemia-reperfusion injuries because of the release of damaging oxygen radicals. A nanobiotechnology-based polyhemogloin-calatase-superoxide dismutase can prevent this because the oxygen carrier, polyhemoglobin, is linked to antioxidant enzymes, catalase and superoxide dismutase. However, these antioxidant enzymes come from nonhuman sources and recombinant human enzymes are expensive. This paper describes our study ...

  2. 过氧化氢酶基因多态性与疾病相关性的研究%The research of association of catalase gene polymorphisms with diseases

    Institute of Scientific and Technical Information of China (English)

    涂茜; 单可人; 官志忠; 任锡麟

    2010-01-01

    Catalase is one of three enzymes within the important huamn antioxidant enzyme system, which also includes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). They coordinate to reduce the production of active oxygen free radicals , to prevent lipid peroxidation and its intermediate metabolites from damaging human body, and to maintain oxidative-antioxidative balance. Catalase gene polymorphisms,and its haplotypes may be related to enzyme activity and transcriptional activity, and thus affect the sensitivity to some human diseases in different individuals. The study reviewed the structure and function of catalase, and gene polymorphism and its association with human diseases.%过氧化氢酶(catalase,CAT)是人体内很重要的一种抗氧化酶,它与超氧化物歧化酶(superoxide dismutase,SOD),谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)共同构成人体重要的抗氧化酶系统,三者协同,减少了活性氧自由基的产生,防止脂质过氧化及其中间代谢产物对机体的损害,维持体内氧化-抗氧化平衡.过氧化氢酶的基因多态性可能与该酶的活性及转录活性有关,从而影响个体间对疾病的易感性不同.

  3. Prevalence of Catalase (-21 A/T Gene Variant in South Indian (Tamil Population

    Directory of Open Access Journals (Sweden)

    A. Lourdhu Mary

    2014-01-01

    Full Text Available Catalase, an endogenous antioxidant enzyme, is responsible for regulating reactive species levels. Several epidemiologic studies have suggested that single nucleotide polymorphism in catalase gene may be associated with many diseases. The genotype of CAT (-21 A/T point mutation in promoter region of catalase gene was determined by polymerase chain based restriction fragment length polymorphism analysis in the DNA of 100 healthy volunteers. The frequency of CAT (-21 A/T gene polymorphism AA, AT, and TT genotypes was found to be 7, 23, and 70 percent, respectively. The mutant “T” allele frequency was found to be 0.82 among the south Indian (Tamil population. Chi square analysis showed that the study population lies within the Hardy-Weinberg equilibrium. The wild type genotype (AA was found to be very low (7% and the mutant genotype (AT/TT was found to be more prevalent (93% among the south Indian population. This suggests that the high prevalence of mutant genotype may increase the susceptibility to oxidative stress associated diseases.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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 (Blt/Blt) 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 Blt mutation renders the protein susceptible to rapid proteolytic degradation

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

    OpenAIRE

    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 lesion...

  7. The monofunctional catalase KatE of Xanthomonas axonopodis pv. citri is required for full virulence in citrus plants.

    Directory of Open Access Journals (Sweden)

    María Laura Tondo

    Full Text Available BACKGROUND: Xanthomonas axonopodis pv. citri (Xac is an obligate aerobic phytopathogen constantly exposed to hydrogen peroxide produced by normal aerobic respiration and by the plant defense response during plant-pathogen interactions. Four putative catalase genes have been identified in silico in the Xac genome, designated as katE, catB, srpA (monofunctional catalases and katG (bifunctional catalase. METHODOLOGY/PRINCIPAL FINDINGS: Xac catalase activity was analyzed using native gel electrophoresis and semi-quantitative RT-PCR. We demonstrated that the catalase activity pattern was regulated in different growth stages displaying the highest levels during the stationary phase. KatE was the most active catalase in this phase of growth. At this stage cells were more resistant to hydrogen peroxide as was determined by the analysis of CFU after the exposition to different H(2O(2 concentrations. In addition, Xac exhibited an adaptive response to hydrogen peroxide, displaying higher levels of catalase activity and H(2O(2 resistance after treatment with sub-lethal concentrations of the oxidant. In the plant-like medium XVM2 the expression of KatE was strongly induced and in this medium Xac was more resistant to H(2O(2. A XackatE mutant strain was constructed by insertional mutagenesis. We observed that catalase induction in stationary phase was lost meanwhile the adaptive response to peroxide was maintained in this mutant. Finally, the XackatE strain was assayed in planta during host plant interaction rendering a less aggressive phenotype with a minor canker formation. CONCLUSIONS: Our results confirmed that in contrast to other Xanthomonas species, Xac catalase-specific activity is induced during the stationary phase of growth in parallel with the bacterial resistance to peroxide challenge. Moreover, Xac catalases expression pattern is modified in response to any stimuli associated with the plant or the microenvironment it provides. The catalase Kat

  8. Inhibition of laminin-5 production in breast epithelial cells by overexpression of p300.

    Science.gov (United States)

    Miller, K A; Chung, J; Lo, D; Jones, J C; Thimmapaya, B; Weitzman, S A

    2000-03-17

    The transcriptional coactivator p300 is essential for normal embryonic development and cellular differentiation. We have been studying the role of p300 in the transcription of a variety of genes, and we became interested in the role of this coactivator in the transcription of genes important in breast epithelial cell biology. From MCF-10A cells (spontaneously immortalized, nontransformed human breast epithelial cells), we developed cell lines that stably overexpress p300. These p300-overexpressing cells displayed reduced adhesion to culture dishes and were found to secrete an extracellular matrix deficient in laminin-5. Laminin-5 is the major extracellular matrix component produced by breast epithelium. Immunofluorescence studies, as well as experiments using normal matrix, confirmed that the decreased adhesion of p300-overexpressing cells is due to laminin-5-deficient extracellular matrix and not due to loss of laminin-5 receptors. Northern blots revealed markedly decreased levels of expression of two of the genes (designated LAMA3 and LAMC2) encoding the alpha3 and gamma2 chains of the laminin-5 heterotrimer in the cells that overexpress p300, whereas LAMB3 mRNA, encoding the third or beta3 chain of laminin-5, was not markedly reduced. Transient transfection experiments with a vector containing a murine LAMA3 promoter demonstrate that overexpressing p300 down-regulates the LAMA3 promoter. In summary, overexpression of p300 leads to down-regulation of laminin-5 production in breast epithelial cells, resulting in decreased adhesion. PMID:10713141

  9. Overexpression of a Triticum aestivum Calreticulin gene (TaCRT1 Improves Salinity Tolerance in Tobacco.

    Directory of Open Access Journals (Sweden)

    Yang Xiang

    Full Text Available Calreticulin (CRT is a highly conserved and abundant multifunctional protein that is encoded by a small gene family and is often associated with abiotic/biotic stress responses in plants. However, the roles played by this protein in salt stress responses in wheat (Triticum aestivum remain obscure. In this study, three TaCRT genes were identified in wheat and named TaCRT1, TaCRT2 and TaCRT3-1 based on their sequence characteristics and their high homology to other known CRT genes. Quantitative real-time PCR expression data revealed that these three genes exhibit different expression patterns in different tissues and are strongly induced under salt stress in wheat. The calcium-binding properties of the purified recombinant TaCRT1 protein were determined using a PIPES/Arsenazo III analysis. TaCRT1 gene overexpression in Nicotiana tabacum decreased salt stress damage in transgenic tobacco plants. Physiological measurements indicated that transgenic tobacco plants showed higher activities of superoxide dismutase (SOD, peroxidase (POD and catalase (CAT than non-transgenic tobacco under normal growth conditions. Interestingly, overexpression of the entire TaCRT1 gene or of partial TaCRT1 segments resulted in significantly higher tolerance to salt stress in transgenic plants compared with their WT counterparts, thus revealing the essential role of the C-domain of TaCRT1 in countering salt stress in plants.

  10. An SNP polymorphism (-844C/T) in the promoter of catalase gene leads to differential expression

    Institute of Scientific and Technical Information of China (English)

    LI Yanping; ZHANG Xin; WANG Zhimin; LU Daru; HANG Wei; JIN Li

    2004-01-01

    @@ Imbalance of redox state has been associated with human diseases, such as cardiovascular diseases, Huntington's disease and Alzheimer's disease[1]. Catalase, an important antioxidant enzyme, decomposes H2O2 into O2and H2O, therefore limiting the deleterious effect of the reactive oxygen species (ROS)[1 -4]. Previous study showed that a C-T polymorphism, located at -844 bp from the translational start site of catalase, is strongly associated with essential hypertension in an isolated Chinese population of Xiangchang country, Anhui Province[5]. To explore the impact of SNP-844C/T on the expression of catalase, human catalase promoters containing either SNP-844C or T variant were subcloned into the pGL3-Basic luciferase vector.

  11. The Role of Neurotransmitters in Protection against Amyloid- β Toxicity by KiSS-1 Overexpression in SH-SY5Y Neurons.

    Science.gov (United States)

    Chilumuri, Amrutha; Milton, Nathaniel G N

    2013-01-01

    Recent studies have suggested that the kisspeptin (KP) and kissorphin (KSO) peptides have neuroprotective actions against the Alzheimer's amyloid- β (A β ) peptide. Overexpression of the human KiSS-1 gene that codes for KP and KSO peptides in SH-SY5Y neurons has also been shown to inhibit A β neurotoxicity. The in vivo actions of KP include activation of neuroendocrine and neurotransmitter systems. The present study used antagonists of KP, neuropeptide FF (NPFF), opioids, oxytocin, estrogen, adrenergic, cholinergic, dopaminergic, serotonergic, and γ -aminobutyric acid (GABA) receptors plus inhibitors of catalase, cyclooxygenase, nitric oxide synthase, and the mitogen activated protein kinase cascade to characterize the KiSS-1 gene overexpression neuroprotection against A β cell model. The results showed that KiSS-1 overexpression is neuroprotective against A β and the action appears to involve the KP or KSO peptide products of KiSS-1 processing. The mechanism of neuroprotection does not involve the activation of the KP or NPFF receptors. Opioids play a role in the toxicity of A β in the KiSS-1 overexpression system and opioid antagonists naloxone or naltrexone inhibited A β toxicity. The mechanism of KiSS-1 overexpression induced protection against A β appears to have an oxytocin plus a cyclooxygenase dependent component, with the oxytocin antagonist atosiban and the cyclooxygenase inhibitor SC-560 both enhancing the toxicity of A β . PMID:24967306

  12. Catalase, superoxide dismutase, and hemolysin activities and heat susceptibility of Listeria monocytogenes after growth in media containing sodium chloride.

    OpenAIRE

    Dallmier, A W; Martin, S E

    1990-01-01

    The activities of catalase, superoxide dismutase, and a thiol-activated hemolysin produced by four strains of Listeria monocytogenes propagated in media containing various concentrations of sodium chloride were examined. L. monocytogenes 7644 showed an increase in catalase, superoxide dismutase, and thiol-activated hemolysin activities when grown in a medium containing 2.5% (wt/vol) NaCl followed by a decrease in activities when propagated in media containing salt concentrations higher than 2...

  13. Release time of residual oxygen after dental bleaching with 35% hydrogen peroxide: effect of a catalase-based neutralizing agent.

    Science.gov (United States)

    Guasso, Bárbara; Salomone, Paloma; Nascimento, Paulo Cícero; Pozzobon, Roselaine Terezinha

    2016-01-01

    This article assessed the effect of a catalase-based agent on residual oxygen (O2) release from teeth exposed to 35% hydrogen peroxide (H2O2). The use of the catalase-based neutralizer agent for 2-3 minutes was able to release residual O2 5 days after exposure to a 35% H2O2-based bleaching gel. PMID:27148658

  14. Low erythrocyte catalase enzyme activity is correlated with high serum total homocysteine levels in tunisian patients with acute myocardial infarction

    OpenAIRE

    Noichri, Yosri; Chalghoum, Abdelkader; Chkioua, Latifa; Baudin, Bruno; Ernez, Samia; Ferchichi, Salima; Miled, Abdelhédi

    2013-01-01

    Background An imbalance between pro-oxidants and antioxidant systems has been suggested to be implicated in the physiopathology of acute myocardial infarction (AMI). We aimed to evaluate the antioxidant capacity in Tunisian patients and to assess the possible relationship between erythrocyte catalase enzyme activity and hyperhomocysteinaemia. Methods 108 patients with AMI and 81 healthy subjects were enrolled in this study. Catalase erythrocyte enzyme activity was determined spectrophotometri...

  15. Contribution of Catalase and Superoxide Dismutase to the Intracellular Survival of Clinical Isolates of Staphylococcus aureus in Murine Macrophages

    OpenAIRE

    Das, Debaditya; Bishayi, Biswadev

    2010-01-01

    The present study was performed in order to carefully investigate the interaction of Staphylococcus aureus with murine macrophages and the contribution of catalase and superoxide dismutase in intracellular persistence of Staphylococcus aureus within murine macrophages during in vitro infection. We have reported that Staphylococcus aureus internalized by murine macrophages did not appear to be rapidly killed. Data indicating the contribution of a single catalase and superoxide dismutase in int...

  16. Influence of ionizing radiation on synthesis and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina

    International Nuclear Information System (INIS)

    Changes in activity and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina following irradiation in early growth period at the doses of 8 and 50 Gy has been studied. Ionizing radiation accelerate the synthesis and degradation rates of catalase and total protein. A comparative study of changes in enzyme and protein turnover during growth on irradiated and non-irradiated medium has been made

  17. Effect of gibberellic acid foliar and kinetin on the antioxidant catalase anzymes and peroxidase in maize under drought stress

    OpenAIRE

    MEHRİ, Shahram

    2015-01-01

    Abstract. To study relation between water scarcity and gibberllic acid hormone and kinetin in three hybrids tested corn in two years as a split plot factorial based on randomized complete block design with 3 replications and antioxidant catalase enzymes and peroxidase leaves, the resulted measuremens are that drought stress is a change in the hormonal balance of corn so that amount of catalase and peroxidase enzymes compared to control were increased by foliar of hormones.however most of the ...

  18. Overexpression of a Chloroplast-located Peroxiredoxin Q Gene, SsPrxQ, Increases the Salt and Low-temperature Tolerance of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Li-Wen Jing; Shi-Hua Chen; Xiao-Li Guo; Hui Zhang; Yan-Xiu Zhao

    2006-01-01

    Abiotic stress, such as salt, drought and extreme temperature,can result in enhanced production of reactive oxygen species (ROS). Plants have developed both enzymatic ROS-scavenging and non-enzymatic ROS-scavenging systems. The major ROS-scavenging enzymes of plants include superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione peroxidase (GPX) and peroxiredoxins (Prxs). In the present work, we identified a gene encoding chloroplast-located peroxiredoxin Q, SsPrxQ, from Suaeda salsa L. Located at chloroplast. Overexpression of SsPrxQ in Arabidopsis leads to an increase in salt and low-temperature tolerance.

  19. Cyclopamine and jervine induce COX-2 overexpression in human erythroleukemia cells but only cyclopamine has a pro-apoptotic effect

    Energy Technology Data Exchange (ETDEWEB)

    Ghezali, Lamia; Leger, David Yannick; Limami, Youness [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Cook-Moreau, Jeanne [Université de Limoges, FR 3503 GEIST, UMR CNRS 7276 “Contrôle de la réponse immune B et lymphoproliférations”, Faculté de Médecine, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Beneytout, Jean-Louis [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Liagre, Bertrand, E-mail: bertrand.liagre@unilim.fr [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France)

    2013-04-15

    Erythroleukemia is generally associated with a very poor response and survival to current available therapeutic agents. Cyclooxygenase-2 (COX-2) has been described to play a crucial role in the proliferation and differentiation of leukemia cells, this enzyme seems to play an important role in chemoresistance in different cancer types. Previously, we demonstrated that diosgenin, a plant steroid, induced apoptosis in HEL cells with concomitant COX-2 overexpression. In this study, we investigated the antiproliferative and apoptotic effects of cyclopamine and jervine, two steroidal alkaloids with similar structures, on HEL and TF1a human erythroleukemia cell lines and, for the first time, their effect on COX-2 expression. Cyclopamine, but not jervine, inhibited cell proliferation and induced apoptosis in these cells. Both compounds induced COX-2 overexpression which was responsible for apoptosis resistance. In jervine-treated cells, COX-2 overexpression was NF-κB dependent. Inhibition of NF-κB reduced COX-2 overexpression and induced apoptosis. In addition, cyclopamine induced apoptosis and COX-2 overexpression via PKC activation. Inhibition of the PKC pathway reduced both apoptosis and COX-2 overexpression in both cell lines. Furthermore, we demonstrated that the p38/COX-2 pathway was involved in resistance to cyclopamine-induced apoptosis since p38 inhibition reduced COX-2 overexpression and increased apoptosis in both cell lines. - Highlights: ► Cyclopamine alone but not jervine induces apoptosis in human erythroleukemia cells. ► Cyclopamine and jervine induce COX-2 overexpression. ► COX-2 overexpression is implicated in resistance to cyclopamine-induced apoptosis. ► Apoptotic potential of jervine is restrained by NF-κB pathway activation. ► PKC is involved in cyclopamine-induced apoptosis and COX-2 overexpression.

  20. Catalase Induced by All-Trans Retinoic Acid Is Involved in Antiproliferation of 36B10 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Woo Yoon [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of); Yu, Jae Ran [Konkuk University College of Medicine, Chungju (Korea, Republic of)

    2010-11-15

    All-trans retinoic acid (ATRA) has antiproliferative effects against brain tumor cells. Recently, ATRA has been reported to induce catalase. We investigated whether catalase induction by ATRA is associated with its antiproliferative effects. 36B10 cells were exposed to 0-50{mu}M ATRA for 24 or 48 hours and mRNA, protein, and activity of catalase were measured. Reactive oxygen species (ROS) were measured using 2',7'-dichlorofluorescin diacetate. A clonogenic assay was used to confirm the cytotoxic effect. The mRNA, protein, and activity of catalase were found to increase in a concentration- and incubation- time-dependent manner. The increase in catalase activity induced by ATRA was decreased by the addition of 3-amino-1,2,4-triazole (ATZ). ROS was also increased with ATRA and decreased by the addition of ATZ. The decrease in cell survival induced by ATRA was partly rescued by ATZ. Catalase induction by ATRA is involved in ROS overproduction and thus inhibits the proliferation of 36B10 cells.

  1. Arabidopsis CALCIUM-DEPENDENT PROTEIN KINASE8 and CATALASE3 Function in Abscisic Acid-Mediated Signaling and H2O2 Homeostasis in Stomatal Guard Cells under Drought Stress.

    Science.gov (United States)

    Zou, Jun-Jie; Li, Xi-Dong; Ratnasekera, Disna; Wang, Cun; Liu, Wen-Xin; Song, Lian-Fen; Zhang, Wen-Zheng; Wu, Wei-Hua

    2015-05-01

    Drought is a major threat to plant growth and crop productivity. Calcium-dependent protein kinases (CDPKs, CPKs) are believed to play important roles in plant responses to drought stress. Here, we report that Arabidopsis thaliana CPK8 functions in abscisic acid (ABA)- and Ca(2+)-mediated plant responses to drought stress. The cpk8 mutant was more sensitive to drought stress than wild-type plants, while the transgenic plants overexpressing CPK8 showed enhanced tolerance to drought stress compared with wild-type plants. ABA-, H2O2-, and Ca(2+)-induced stomatal closing were impaired in cpk8 mutants. Arabidopsis CATALASE3 (CAT3) was identified as a CPK8-interacting protein, confirmed by yeast two-hybrid, coimmunoprecipitation, and bimolecular fluorescence complementation assays. CPK8 can phosphorylate CAT3 at Ser-261 and regulate its activity. Both cpk8 and cat3 plants showed lower catalase activity and higher accumulation of H2O2 compared with wild-type plants. The cat3 mutant displayed a similar drought stress-sensitive phenotype as cpk8 mutant. Moreover, ABA and Ca(2+) inhibition of inward K(+) currents were diminished in guard cells of cpk8 and cat3 mutants. Together, these results demonstrated that CPK8 functions in ABA-mediated stomatal regulation in responses to drought stress through regulation of CAT3 activity. PMID:25966761

  2. Kif14 overexpression accelerates murine retinoblastoma development.

    Science.gov (United States)

    O'Hare, Michael; Shadmand, Mehdi; Sulaiman, Rania S; Sishtla, Kamakshi; Sakisaka, Toshiaki; Corson, Timothy W

    2016-10-15

    The mitotic kinesin KIF14 has an essential role in the recruitment of proteins required for the final stages of cytokinesis. Genomic gain and/or overexpression of KIF14 has been documented in retinoblastoma and a number of other cancers, such as breast, lung and ovarian carcinomas, strongly suggesting its role as an oncogene. Despite evidence of oncogenic properties in vitro and in xenografts, Kif14's role in tumor progression has not previously been studied in a transgenic cancer model. Using a novel Kif14 overexpressing, simian virus 40 large T-antigen retinoblastoma (TAg-RB) double transgenic mouse model, we aimed to determine Kif14's role in promoting retinal tumor formation. Tumor initiation and development in double transgenics and control TAg-RB littermates were documented in vivo over a time course by optical coherence tomography, with subsequent ex vivo quantification of tumor burden. Kif14 overexpression led to an accelerated initiation of tumor formation in the TAg-RB model and a significantly decreased tumor doubling time (1.8 vs. 2.9 weeks). Moreover, overall percentage tumor burden was also increased by Kif14 overexpression. These data provide the first evidence that Kif14 can promote tumor formation in susceptible cells in vivo. PMID:27270502

  3. Changes in the TBARs content and superoxide dismutase, catalase and glutathione peroxidase activities in the lymphoid organs and skeletal muscles of adrenodemedullated rats

    Directory of Open Access Journals (Sweden)

    Pereira B.

    1998-01-01

    Full Text Available Thiobarbituric acid reactant substances (TBARs content, and the activities of glucose-6-phosphate dehydrogenase (G6PDh, citrate synthase (CS, Cu/Zn- and Mn-superoxide dismutase (SOD, catalase, and glutathione peroxidase (GPX were measured in the lymphoid organs (thymus, spleen, and mesenteric lymph nodes (MLN and skeletal muscles (gastrocnemius and soleus of adrenodemedullated (ADM rats. The results were compared with those obtained for sham-operated rats. TBARs content was reduced by adrenodemedullation in the lymphoid organs (MLN (28%, thymus (40% and spleen (42% and gastrocnemius muscle (67%. G6PDh activity was enhanced in the MLN (69% and reduced in the spleen (28% and soleus muscle (75%. CS activity was reduced in all tissues (MLN (75%, spleen (71%, gastrocnemius (61% and soleus (43%, except in the thymus which displayed an increment of 56%. Cu/Zn-SOD activity was increased in the MLN (126%, thymus (223%, spleen (80% and gastrocnemius muscle (360% and was reduced in the soleus muscle (31%. Mn-SOD activity was decreased in the MLN (67% and spleen (26% and increased in the thymus (142%, whereas catalase activity was reduced in the MLN (76%, thymus (54% and soleus muscle (47%. It is particularly noteworthy that in ADM rats the activity of glutathione peroxidase was not detectable by the method used. These data are consistent with the possibility that epinephrine might play a role in the oxidative stress of the lymphoid organs. Whether this fact represents an important mechanism for the establishment of impaired immune function during stress remains to be elucidated.

  4. Highly Active and Stable Large Catalase Isolated from a Hydrocarbon Degrading Aspergillus terreus MTCC 6324.

    Science.gov (United States)

    Vatsyayan, Preety; Goswami, Pranab

    2016-01-01

    A hydrocarbon degrading Aspergillus terreus MTCC 6324 produces a high level of extremely active and stable cellular large catalase (CAT) during growth on n-hexadecane to combat the oxidative stress caused by the hydrocarbon degrading metabolic machinery inside the cell. A 160-fold purification with specific activity of around 66 × 10(5) U mg(-1) protein was achieved. The native protein molecular mass was 368 ± 5 kDa with subunit molecular mass of nearly 90 kDa, which indicates that the native CAT protein is a homotetramer. The isoelectric pH (pI) of the purified CAT was 4.2. BLAST aligned peptide mass fragments of CAT protein showed its highest similarity with the catalase B protein from other fungal sources. CAT was active in a broad range of pH 4 to 12 and temperature 25°C to 90°C. The catalytic efficiency (K cat/K m ) of 4.7 × 10(8) M(-1) s(-1) within the studied substrate range and alkaline pH stability (half-life, t 1/2 at pH 12~15 months) of CAT are considerably higher than most of the extensively studied catalases from different sources. The storage stability (t 1/2) of CAT at physiological pH 7.5 and 4°C was nearly 30 months. The haem was identified as haem b by electrospray ionization tandem mass spectroscopy (ESI-MS/MS). PMID:27057351

  5. Respiration triggers heme transfer from cytochrome c peroxidase to catalase in yeast mitochondria.

    Science.gov (United States)

    Kathiresan, Meena; Martins, Dorival; English, Ann M

    2014-12-01

    In exponentially growing yeast, the heme enzyme, cytochrome c peroxidase (Ccp1) is targeted to the mitochondrial intermembrane space. When the fermentable source (glucose) is depleted, cells switch to respiration and mitochondrial H2O2 levels rise. It has long been assumed that CCP activity detoxifies mitochondrial H2O2 because of the efficiency of this activity in vitro. However, we find that a large pool of Ccp1 exits the mitochondria of respiring cells. We detect no extramitochondrial CCP activity because Ccp1 crosses the outer mitochondrial membrane as the heme-free protein. In parallel with apoCcp1 export, cells exhibit increased activity of catalase A (Cta1), the mitochondrial and peroxisomal catalase isoform in yeast. This identifies Cta1 as a likely recipient of Ccp1 heme, which is supported by low Cta1 activity in ccp1Δ cells and the accumulation of holoCcp1 in cta1Δ mitochondria. We hypothesized that Ccp1's heme is labilized by hyperoxidation of the protein during the burst in H2O2 production as cells begin to respire. To test this hypothesis, recombinant Ccp1 was hyperoxidized with excess H2O2 in vitro, which accelerated heme transfer to apomyoglobin added as a surrogate heme acceptor. Furthermore, the proximal heme Fe ligand, His175, was found to be ∼ 85% oxidized to oxo-histidine in extramitochondrial Ccp1 isolated from 7-d cells, indicating that heme labilization results from oxidation of this ligand. We conclude that Ccp1 responds to respiration-derived H2O2 via a previously unidentified mechanism involving H2O2-activated heme transfer to apoCta1. Subsequently, the catalase activity of Cta1, not CCP activity, contributes to mitochondrial H2O2 detoxification. PMID:25422453

  6. Overexpression of Fatty-Acid-β-Oxidation-Related Genes Extends the Lifespan of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Shin-Hae Lee

    2012-01-01

    Full Text Available A better understanding of the aging process is necessary to ensure that the healthcare needs of an aging population are met. With the trend toward increased human life expectancies, identification of candidate genes affecting the regulation of lifespan and its relationship to environmental factors is essential. Through misexpression screening of EP mutant lines, we previously isolated several genes extending lifespan when ubiquitously overexpressed, including the two genes encoding the fatty-acid-binding protein and dodecenoyl-CoA delta-isomerase involved in fatty-acid β-oxidation, which is the main energy resource pathway in eukaryotic cells. In this study, we analyzed flies overexpressing the two main components of fatty-acid β-oxidation, and found that overexpression of fatty-acid-β-oxidation-related genes extended the Drosophila lifespan. Furthermore, we found that the ability of dietary restriction to extend lifespan was reduced by the overexpression of fatty-acid-β-oxidation-related genes. Moreover, the overexpression of fatty-acid-β-oxidation-related genes enhanced stress tolerance to oxidative and starvation stresses and activated the dFOXO signal, indicating translocation to the nucleus and transcriptional activation of the dFOXO target genes. Overall, the results of this study suggest that overexpression of fatty-acid-β-oxidation-related genes extends lifespan in a dietary-restriction-related manner, and that the mechanism of this process may be related to FOXO activation.

  7. Glutathione S-transferase and Catalase gene polymorphisms with Type 2 diabetes mellitus.

    OpenAIRE

    Pushpank Vats; Honey Chandra; Monisha Banerjee

    2013-01-01

    Background and Aim: Antioxidant enzymes such as glutathione S-transferases (GSTs) and catalase (CAT) play important roles in cellular defense by detoxifying various toxic substrates and can be used as important biomarkers for T2DM. The aim of the present work was to study the association of GST and CAT gene polymorphism with T2DM cases and controls in north Indian population. Materials and Methods: Polymorphic GST gene isoforms, GSTM1, T1 and P1 were investigated in 201 healthy control su...

  8. In Vivo Role of Catalase-Peroxidase in Synechocystis sp. Strain PCC 6803

    OpenAIRE

    Tichy, Martin; Vermaas, Wim

    1999-01-01

    The katG gene coding for the only catalase-peroxidase in the cyanobacterium Synechocystis sp. strain PCC 6803 was deleted in this organism. Although the rate of H2O2 decomposition was about 30 times lower in the ΔkatG mutant than in the wild type, the strain had a normal phenotype and its doubling time as well as its resistance to H2O2 and methyl viologen were indistinguishable from those of the wild type. The residual H2O2-scavenging capacity was more than sufficient to deal with the rate of...

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

    OpenAIRE

    Rachel E Pritchard; 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 d...

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

    International Nuclear Information System (INIS)

    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.

  11. Catalase-negative Staphylococcus aureus isolated from a diabetic foot ulcer

    Directory of Open Access Journals (Sweden)

    MR Zali

    2010-12-01

    Full Text Available We report a catalase-negative Staphylococcus aureus isolated from a 56-year-old male diabetic patient with foot ulcer who attended our surgery ward. Species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc and fem genes. Antibiotic susceptibility showed that the strain was sensitive to imepenem, chloramphenicol, amoxicillin, vancomycin and resistant to oxacillin, penicillin, ceftriaxone, erythromycin, clindamycin, and amikacin. Clinicians and microbiologists must be encouraged to identify and report these atypical strains and the infections associated with them in order to establish their role in pathogenesis.

  12. Biomimetic Mn-Catalases Based on Dimeric Manganese Complexes in Mesoporous Silica for Potential Antioxidant Agent.

    Science.gov (United States)

    Escriche-Tur, Luis; Corbella, Montserrat; Font-Bardia, Mercè; Castro, Isabel; Bonneviot, Laurent; Albela, Belén

    2015-11-01

    Two new structural and functional models of the Mn-catalase with formula [{Mn(III)(bpy)(H2O)}(μ-2-MeOC6H4CO2)2(μ-O){Mn(III)(bpy)(X)}]X, where X = NO3 (1) and ClO4 (2) and bpy = 2,2'-bipyridine, were synthesized and characterized by X-ray diffraction. In both cases, a water molecule and an X ion occupy the monodentate positions. The magnetic properties of these compounds reveal a weak antiferromagnetic behavior (2J = -2.2 cm(-1) for 1 and -0.7 cm(-1) for 2, using the spin Hamiltonian H = -2J S1·S2) and negative zero-field splitting parameter DMn (-4.6 cm(-1) and -3.0 cm(-1) for 1 and 2, respectively). This fact, together with the nearly orthogonal orientation of the Jahn-Teller axes of the Mn(III) ions explain the unusual shape of χMT versus T plot at low temperature. Compound 1 presents a better catalase activity than 2 in CH3CN-H2O media, probably due to a beneficial interaction of the NO3(-) ion with the Mn complex in solution. These compounds were successfully inserted inside two-dimensional hexagonal mesoporous silica (MCM-41 type) leading to the same hybrid material ([Mn2O]@SiO2), without the X group. The manganese complex occupies approximately half of the available pore volume, keeping the silica's hexagonal array intact. Magnetic measurements of [Mn2O]@SiO2 suggest that most of the dinuclear unit is preserved, as a non-negligible interaction between Mn ions is still observed. The X-ray photoelectron spectroscopy analysis of the Mn 3s peak confirms that Mn remains as Mn(III) inside the silica. The catalase activity study of material [Mn2O]@SiO2 reveals that the complex is more active inside the porous silica, probably due to the surface silanolate groups of the pore wall. Moreover, the new material shows catalase activity in water media, while the coordination compounds are not active. PMID:26484833

  13. Isonicotinic Acid Hydrazide Conversion to Isonicotinyl-NAD by Catalase-peroxidases*

    OpenAIRE

    Wiseman, Ben; Carpena, Xavi; Feliz, Miguel; Donald, Lynda J.; Pons, Miquel; Fita, Ignacio; Loewen, Peter C.

    2010-01-01

    Activation of the pro-drug isoniazid (INH) as an anti-tubercular drug in Mycobacterium tuberculosis involves its conversion to isonicotinyl-NAD, a reaction that requires the catalase-peroxidase KatG. This report shows that the reaction proceeds in the absence of KatG at a slow rate in a mixture of INH, NAD+, Mn2+, and O2, and that the inclusion of KatG increases the rate by >7 times. Superoxide, generated by either Mn2+- or KatG-catalyzed reduction of O2, is an essential intermediate in the r...

  14. Activity of Superoxide Dismutase and Catalase in Fenugreek (Trigonella foenum-graecum) in Response to Carbendazim.

    Science.gov (United States)

    Sangeetha, R

    2010-01-01

    Fenugreek (Trigonella foenum-graecum) is an annual herb, used as a spice and traditionally as medicine. Fenugreek finds its uses in treating hyperglycemia, hyperlipidemia and disorders of gastro-intestinal and cardiovascular systems. Fenugreek cultivation in India is affected by fungal diseases like root-rot and damping-off and fungicides like carbendazim are used to overcome these infections. Fungicides play both positive and negative role in plants; fungicides protect plants from diseases and also exert oxidative stress simultaneously. This report is on the response of antioxidants, superoxide dismutase and catalase in fenugreek seeds and plants treated to different concentrations of carbendazim. PMID:20582202

  15. Crystallization and preliminary structural analysis of catalase A from Saccharomyces cerevisiae.

    OpenAIRE

    Berthet, S.; Nykyri, L. M.; Bravo, J; Mate, M. J.; Berthet-Colominas, C; Alzari, P M; Koller, F.; Fita, I

    1997-01-01

    Yeast peroxisomal catalase A, obtained at high yields by over expression of the C-terminally modified gene from a 2 mu-plasmid, has been crystallized in a form suitable for high resolution X-ray diffraction studies. Brownish crystals with bipyrimidal morphology and reaching ca. 0.8 mm in size were produced by the hanging drop method using ammonium sulphate as precipitant. These crystals diffract better than 2.0 A resolution and belong to the hexagonal space group P6(1)22 with unit cell parame...

  16. Overexpression of Cotton GhMPK11 Decreases Disease Resistance through the Gibberellin Signaling Pathway in Transgenic Nicotiana benthamiana

    Science.gov (United States)

    Wang, Fang; Wang, Chen; Yan, Yan; Jia, Haihong; Guo, Xingqi

    2016-01-01

    Many changes in development, growth, hormone activity and environmental stimuli responses are mediated by mitogen-activated protein kinase (MAPK) cascades. However, in plants, studies on MAPKs have mainly focused on MPK3, MPK4 and MPK6. Here, a novel group B MAPK gene, GhMPK11, was isolated from cotton (Gossypium hirsutum L.) and characterized. Both promoter and expression pattern analyses revealed that GhMPK11 is involved in defense responses and signaling pathways. GhMPK11 overexpression in Nicotiana benthamiana plants could increase gibberellin 3 (GA3) content through the regulation of GA-related genes. Interestingly, either GhMPK11 overexpression or exogenous GA3 treatment in N. benthamiana plants could enhance the susceptibility of these plants to the infectious pathogens Ralstonia solanacearum and Rhizoctonia solani. Moreover, reactive oxygen species (ROS) accumulation was increased after pathogen infiltration due to the increased expression of ROS-related gene respiratory burst oxidative homologs (RbohB) and the decreased expression or activity of ROS detoxification enzymes regulated by GA3, such as superoxide dismutases (SODs), peroxidases (PODs), catalase (CAT) and glutathione S-transferase (GST). Taken together, these results suggest that GhMPK11 overexpression could enhance the susceptibility of tobacco to pathogen infection through the GA3 signaling pathway via down-regulation of ROS detoxification enzymes. PMID:27242882

  17. Overexpression of Cotton GhMPK11 Decreases Disease Resistance through the Gibberellin Signaling Pathway in Transgenic Nicotiana benthamiana.

    Science.gov (United States)

    Wang, Fang; Wang, Chen; Yan, Yan; Jia, Haihong; Guo, Xingqi

    2016-01-01

    Many changes in development, growth, hormone activity and environmental stimuli responses are mediated by mitogen-activated protein kinase (MAPK) cascades. However, in plants, studies on MAPKs have mainly focused on MPK3, MPK4 and MPK6. Here, a novel group B MAPK gene, GhMPK11, was isolated from cotton (Gossypium hirsutum L.) and characterized. Both promoter and expression pattern analyses revealed that GhMPK11 is involved in defense responses and signaling pathways. GhMPK11 overexpression in Nicotiana benthamiana plants could increase gibberellin 3 (GA3) content through the regulation of GA-related genes. Interestingly, either GhMPK11 overexpression or exogenous GA3 treatment in N. benthamiana plants could enhance the susceptibility of these plants to the infectious pathogens Ralstonia solanacearum and Rhizoctonia solani. Moreover, reactive oxygen species (ROS) accumulation was increased after pathogen infiltration due to the increased expression of ROS-related gene respiratory burst oxidative homologs (RbohB) and the decreased expression or activity of ROS detoxification enzymes regulated by GA3, such as superoxide dismutases (SODs), peroxidases (PODs), catalase (CAT) and glutathione S-transferase (GST). Taken together, these results suggest that GhMPK11 overexpression could enhance the susceptibility of tobacco to pathogen infection through the GA3 signaling pathway via down-regulation of ROS detoxification enzymes. PMID:27242882

  18. Overexpression of copper/zinc superoxide dismutase from mangrove Kandelia candel in tobacco enhances salinity tolerance by the reduction of reactive oxygen species in chloroplast

    Directory of Open Access Journals (Sweden)

    Xiaoshu eJing

    2015-01-01

    Full Text Available Na+ uptake and transport in Kandelia candel and antioxidative defense were investigated under rising NaCl stress from 100 mM to 300 mM. Salinized K. candel roots had a net Na+ efflux with a declined flux rate during an extended NaCl exposure. Na+ buildup in leaves enhanced H2O2 levels, superoxide dismutase (SOD activity, and increased transcription of CSD gene encoding a Cu/Zn SOD. Sequence and subcellular localization analyses have revealed that KcCSD is a typical Cu/Zn SOD in chloroplast. The transgenic tobacco experimental system was used as a functional genetics model to test the effect of KcCSD on salinity tolerance. KcCSD-transgenic lines were more Na+ tolerant than wild-type (WT tobacco in terms of lipid peroxidation, root growth, and survival rate. In the latter, 100 mM NaCl led to a remarkable reduction in chlorophyll content and a/b ratio, decreased maximal chlorophyll a fluorescence, and photochemical efficiency of photosystem II. NaCl stress in WT resulted from H2O2 burst in chloroplast. Na+ injury to chloroplast was less pronounced in KcCSD-transgenic plants due to upregulated antioxidant defense. KcCSD-transgenic tobacco enhanced SOD activity by an increment in SOD isoenzymes under 100 mM NaCl stress from 24 h to 7 d. Catalase activity rose in KcCSD overexpressing tobacco plants. KcCSD-transgenic plants better scavenged NaCl-elicited reactive oxygen species (ROS compared to WT ones. In conclusion, K. candel effectively excluded Na+ in roots during a short exposure; and increased CSD expression to reduce ROS in chloroplast in a long-term and high saline environment.

  19. Overexpression of receptor-like kinase ERECTA improves thermotolerance in rice and tomato.

    Science.gov (United States)

    Shen, Hui; Zhong, Xiangbin; Zhao, Fangfang; Wang, Yanmei; Yan, Bingxiao; Li, Qun; Chen, Genyun; Mao, Bizeng; Wang, Jianjun; Li, Yangsheng; Xiao, Guoying; He, Yuke; Xiao, Han; Li, Jianming; He, Zuhua

    2015-09-01

    The detrimental effects of global warming on crop productivity threaten to reduce the world's food supply. Although plant responses to changes in temperature have been studied, genetic modification of crops to improve thermotolerance has had little success to date. Here we demonstrate that overexpression of the Arabidopsis thaliana receptor-like kinase ERECTA (ER) in Arabidopsis, rice and tomato confers thermotolerance independent of water loss and that Arabidopsis er mutants are hypersensitive to heat. A loss-of-function mutation of a rice ER homolog and reduced expression of a tomato ER allele decreased thermotolerance of both species. Transgenic tomato and rice lines overexpressing Arabidopsis ER showed improved heat tolerance in the greenhouse and in field tests at multiple locations in China during several seasons. Moreover, ER-overexpressing transgenic Arabidopsis, tomato and rice plants had increased biomass. Our findings could contribute to engineering or breeding thermotolerant crops with no growth penalty. PMID:26280413

  20. Ameliorating replicative senescence of human bone marrow stromal cells by PSMB5 overexpression

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Li, E-mail: luli7300@126.com [Department of Anatomy, Shanxi Medical University, Taiyuan 030001 (China); Song, Hui-Fang; Wei, Jiao-Long; Liu, Xue-Qin [Department of Anatomy, Shanxi Medical University, Taiyuan 030001 (China); Song, Wen-Hui [Department of Orthopaedics, The Second Affiliated Hospital of Shanxi Medical University, Taiyuan 030001 (China); Yan, Ba-Yi; Yang, Gui-Jiao [Department of Anatomy, Shanxi Medical University, Taiyuan 030001 (China); Li, Ang [Department of Medicine, University of Hong Kong Faculty of Medicine, Hong Kong (Hong Kong); Department of Anatomy, University of Hong Kong Faculty of Medicine, Hong Kong (Hong Kong); Yang, Wu-Lin, E-mail: wulinyoung@163.com [School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009 (China); Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research - A*STAR (Singapore)

    2014-01-24

    Highlights: • PSMB5 overexpression restores the differentiation potential of aged hBMSCs. • PSMB5 overexpression enhances the proteasomal activity of late-stage hBMSCs. • PSMB5 overexpression inhibits replicative senescence and improved cell viability. • PSMB5 overexpression promotes cell growth by upregulating the Cyclin D1/CDK4 complex. - Abstract: Multipotent human bone marrow stromal cells (hBMSCs) potentially serve as a source for cell-based therapy in regenerative medicine. However, in vitro expansion was inescapably accompanied with cell senescence, characterized by inhibited proliferation and compromised pluripotency. We have previously demonstrated that this aging process is closely associated with reduced 20S proteasomal activity, with down-regulation of rate-limiting catalytic β-subunits particularly evident. In the present study, we confirmed that proteasomal activity directly contributes to senescence of hBMSCs, which could be reversed by overexpression of the β5-subunit (PSMB5). Knocking down PSMB5 led to decreased proteasomal activity concurrent with reduced cell proliferation in early-stage hBMSCs, which is similar to the senescent phenotype observed in late-stage cells. In contrast, overexpressing PSMB5 in late-stage cells efficiently restored the normal activity of 20S proteasomes and promoted cell growth, possibly via upregulating the Cyclin D1/CDK4 complex. Additionally, PSMB5 could enhance cell resistance to oxidative stress, as evidenced by the increased cell survival upon exposing senescent hBMSCs to hydrogen peroxide. Furthermore, PSMB5 overexpression retained the pluripotency of late-stage hBMSCs by facilitating their neural differentiation both in vitro and in vivo. Collectively, our work reveals a critical role of PSMB5 in 20S proteasome-mediated protection against replicative senescence, pointing to a possible strategy for maintaining the integrity of culture-expanded hBMSCs by manipulating the expression of PSMB5.

  1. Ameliorating replicative senescence of human bone marrow stromal cells by PSMB5 overexpression

    International Nuclear Information System (INIS)

    Highlights: • PSMB5 overexpression restores the differentiation potential of aged hBMSCs. • PSMB5 overexpression enhances the proteasomal activity of late-stage hBMSCs. • PSMB5 overexpression inhibits replicative senescence and improved cell viability. • PSMB5 overexpression promotes cell growth by upregulating the Cyclin D1/CDK4 complex. - Abstract: Multipotent human bone marrow stromal cells (hBMSCs) potentially serve as a source for cell-based therapy in regenerative medicine. However, in vitro expansion was inescapably accompanied with cell senescence, characterized by inhibited proliferation and compromised pluripotency. We have previously demonstrated that this aging process is closely associated with reduced 20S proteasomal activity, with down-regulation of rate-limiting catalytic β-subunits particularly evident. In the present study, we confirmed that proteasomal activity directly contributes to senescence of hBMSCs, which could be reversed by overexpression of the β5-subunit (PSMB5). Knocking down PSMB5 led to decreased proteasomal activity concurrent with reduced cell proliferation in early-stage hBMSCs, which is similar to the senescent phenotype observed in late-stage cells. In contrast, overexpressing PSMB5 in late-stage cells efficiently restored the normal activity of 20S proteasomes and promoted cell growth, possibly via upregulating the Cyclin D1/CDK4 complex. Additionally, PSMB5 could enhance cell resistance to oxidative stress, as evidenced by the increased cell survival upon exposing senescent hBMSCs to hydrogen peroxide. Furthermore, PSMB5 overexpression retained the pluripotency of late-stage hBMSCs by facilitating their neural differentiation both in vitro and in vivo. Collectively, our work reveals a critical role of PSMB5 in 20S proteasome-mediated protection against replicative senescence, pointing to a possible strategy for maintaining the integrity of culture-expanded hBMSCs by manipulating the expression of PSMB5

  2. Six1 overexpression at early stages of HPV16-mediated transformation of human keratinocytes promotes differentiation resistance and EMT

    International Nuclear Information System (INIS)

    Previous studies in our laboratory discovered that SIX1 mRNA expression increased during in vitro progression of HPV16-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. In this study, we explored the role of Six1 at early stages of HPV16-mediated transformation by overexpressing Six1 in HKc/HPV16. We found that Six1 overexpression in HKc/HPV16 increased cell proliferation and promoted cell migration and invasion by inducing epithelial–mesenchymal transition (EMT). Moreover, the overexpression of Six1 in HKc/HPV16 resulted in resistance to serum and calcium-induced differentiation, which is the hallmark of the HKc/DR phenotype. Activation of MAPK in HKc/HPV16 overexpressing Six1 is linked to resistance to calcium-induced differentiation. In conclusion, this study determined that Six1 overexpression resulted in differentiation resistance and promoted EMT at early stages of HPV16-mediated transformation of human keratinocytes. - Highlights: • Six1 expression increases during HPV16-mediated transformation. • Six1 overexpression causes differentiation resistance in HPV16-immortalized cells. • Six1 overexpression in HPV16-immortalized keratinocytes activates MAPK. • Activation of MAPK promotes EMT and differentiation resistance. • Six1 overexpression reduces Smad-dependent TGF-β signaling

  3. Six1 overexpression at early stages of HPV16-mediated transformation of human keratinocytes promotes differentiation resistance and EMT

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hanwen [Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208 (United States); Pirisi, Lucia [Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, University of South Carolina, Columbia, SC 29208 (United States); Creek, Kim E., E-mail: creekk@sccp.sc.edu [Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208 (United States)

    2015-01-01

    Previous studies in our laboratory discovered that SIX1 mRNA expression increased during in vitro progression of HPV16-immortalized human keratinocytes (HKc/HPV16) toward a differentiation-resistant (HKc/DR) phenotype. In this study, we explored the role of Six1 at early stages of HPV16-mediated transformation by overexpressing Six1 in HKc/HPV16. We found that Six1 overexpression in HKc/HPV16 increased cell proliferation and promoted cell migration and invasion by inducing epithelial–mesenchymal transition (EMT). Moreover, the overexpression of Six1 in HKc/HPV16 resulted in resistance to serum and calcium-induced differentiation, which is the hallmark of the HKc/DR phenotype. Activation of MAPK in HKc/HPV16 overexpressing Six1 is linked to resistance to calcium-induced differentiation. In conclusion, this study determined that Six1 overexpression resulted in differentiation resistance and promoted EMT at early stages of HPV16-mediated transformation of human keratinocytes. - Highlights: • Six1 expression increases during HPV16-mediated transformation. • Six1 overexpression causes differentiation resistance in HPV16-immortalized cells. • Six1 overexpression in HPV16-immortalized keratinocytes activates MAPK. • Activation of MAPK promotes EMT and differentiation resistance. • Six1 overexpression reduces Smad-dependent TGF-β signaling.

  4. Ultraviolet influence on catalase activity and mineral content in eyeballs of gibel carp (Carassius auratus gibelio)

    Energy Technology Data Exchange (ETDEWEB)

    Formicki, Grzegorz [Cracow Pedagogical Academy, Institute of Biology, Department of Zoology, ul. Podbrzezie 3, 31-054 Cracow (Poland)]. E-mail: formicki@ap.krakow.pl; Stawarz, Robert [Cracow Pedagogical Academy, Institute of Biology, Department of Zoology, ul. Podbrzezie 3, 31-054 Cracow (Poland)

    2006-10-01

    UV radiation present in the environment may induce several eye disorders including inflammation and cataract. The aim of this work was to study catalase activity and Mg, Cu, Ca and Zn contents in the eyeballs of gibel carp exposed to ecologically relevant doses of UV radiation (0.09 kJ/m{sup 2} for UV-A and 0.98 kJ/m{sup 2} for UV-B) simulated in laboratory conditions. Ultraviolet exposure resulted in significant reduction of catalase activity in the eyeballs of tested fish. Reductions in Mg, Cu and Ca contents after UV exposure were also observed. The differences in Mg and Cu levels between control and UV exposed animals were statistically significant, whereas the reduction of Ca level was insignificant. Zinc level in the eyeballs of UV-exposed fish was significantly higher than in non-irradiated specimens. The results suggest that ultraviolet radiation affects prooxidant/antioxidant balance and Mg, Cu, Zn contents in the eyes of fish living in shallow habitats. These may lead to cataract formation.

  5. Superoxide dismutase, catalase, and. alpha. -tocopherol content of stored potato tubers. [Solanum tuberosum L

    Energy Technology Data Exchange (ETDEWEB)

    Spychalla, J.P.; Desborough, S.L. (Univ. of Minnesota, St. Paul (USA))

    1990-11-01

    Activated oxygen or oxygen free radical mediated damage to plants has been established or implicated in many plant stress situations. The extent of activated oxygen damage to potato (Solanum tuberosum L.) tubers during low temperature storage and long-term storage is not known. Quantitation of oxygen free radical mediated damage in plant tissues is difficult. However, it is comparatively easy to quantitate endogenous antioxidants, which detoxify potentially damaging forms of activated oxygen. Three tuber antioxidants, superoxide dismutase, catalase, and {alpha}-tocopherol were assayed from four potato cultivars stored at 3{degree}C and 9{degree}C for 40 weeks. Tubers stored at 3{degree}C demonstrated increased superoxide dismutase activities (up to 72%) compared to tubers stored at 9{degree}C. Time dependent increases in the levels of superoxide dismutase, catalase, and {alpha}-tocopherol occurred during the course of the 40 week storage. The possible relationship between these increases in antioxidants and the rate of activated oxygen production in the tubers is discussed.

  6. Comprehensive Functional Analysis of the Catalase Gene Family in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Yan-Yan Du; Peng-Cheng Wang; Jia Chen; Chun-Peng Song

    2008-01-01

    In Arabidopsis, catalase (CAT) genes encode a small family of proteins including CAT1, CAT2 and CAT3, which catalyze the decomposition of hydrogen peroxide (H2O2) and play an important role in controlling homeostasis of reactive oxygen species (ROS). Here, we analyze the expression profiles and activities of three catalases under different treatments including drought, cold, oxidative stresses, abscisic acid and salicylic acid in Arabidopsis. Our results reveal that CAT1 is an important player in the removal of H2O2 generated under various environmental stresses. CAT2 and CAT3 are major H2O2 scavengers that contribute to ROS homeostasis in light or darkness, respectively. In addition, CAT2 is activated by cold and drought stresses and CAT3 is mainly enhanced by abscisic acid and oxidative treatments as well as at the senescence stage. These results, together with previous data, suggest that the network of transcriptional control explains how CATs and other scavenger enzymes such as peroxidase and superoxide dismutase may be coordinately regulated during development, but differentially expressed in response to different stresses for controlling ROS homeostasis.

  7. Mn(II) complexes with bipyridine, phenanthroline and benzoic acid: Biological and catalase-like activity

    Indian Academy of Sciences (India)

    Ibrahim Kani; Özlem Atlier; Kiymet Güven

    2016-04-01

    Five mononuclear Mn(II) complexes, [Mn(phen)2(ClO4)2] (1), [Mn(phen)3](ClO4)2(H2CO3)2(2), [Mn(bipy)2(ClO4)2] (3), [Mn(bipy)3](ClO4)2) (4), and Mn(phen)2(ba)(H2O)](ClO4)(CH3OH) (5), where bipy = 2,2’-bipyridine, phen = 1,10-phenanthroline, and ba = benzoic acid were prepared and characterized by Xray, IR and UV-Vis spectroscopies, and their catalase-like and biological activities were studied. The presence of two different types and the number of chelating NN-donor neutral ligands allowed for analysis of their effects on the catalase and biological activities. It was observed that the presence and number of phen ligands improved the activity more than the bipy ligand. Complexes 1 and 2, which contain more basic phen ligands, disproportionate H2O2 faster than complexes 3 and 4, which contain less basic bipy ligands. The in vitro antimicrobial activities of all the complexes were also tested against seven bacterial strains by microdilution tests. All the bacterial isolates demonstrated sensitivity to the complexes and the antifungal (anticandidal) activities of the Mn(II) complexes were remarkably higher than the reference drug ketoconazole.

  8. Overexpressed TP73 induces apoptosis in medulloblastoma

    OpenAIRE

    Perlaky Laszlo; Adesina Adekunle M; Rajan Jessen A; Skapura Darlene G; Lin Linda L; De Bortoli Massimiliano; Castellino Robert C; Irwin Meredith S; Kim John YH

    2007-01-01

    Abstract Background Medulloblastoma is the most common malignant brain tumor of childhood. Children who relapse usually die of their disease, which reflects resistance to radiation and/or chemotherapy. Improvements in outcome require a better understanding of the molecular basis of medulloblastoma growth and treatment response. TP73 is a member of the TP53 tumor suppressor gene family that has been found to be overexpressed in a variety of tumors and mediates apoptotic responses to genotoxic ...

  9. Effects of some environmental parameters on catalase activity measured in the mussel (Mytilus galloprovincialis) exposed to lindane

    International Nuclear Information System (INIS)

    Mussels (Mytilus galloprovincialis), collected from the Bizerta lagoon, were acclimated for four days to various conditions of temperature, salinity, photoperiod and food supply and then exposed to lindane at a concentration of 40 μg l-1. Catalase activity, which is a biomarker of exposure to an oxidative stress, was measured in the whole soft tissues of control and assay groups. In control mussels, high temperature, high salinity and light duration significantly increased catalase activity whereas this activity decreased when food, composed of freeze-dried, algae was available. When mussels were treated with lindane, catalase activities were higher than in controls. This increase was significant with temperature, salinity and light duration. The food supply did not change catalase activity, which was always higher compared to controls. Oxidative stress was shown in mussels exposed to lindane. The results highlight the need of considering abiotic parameters in biomonitoring studies, and especially when using catalase as a biomarker. - Oxidative stress in mussels exposed to lindane was also influenced by a number of abiotic parameters

  10. Important role of catalase in the cellular response of the budding yeast Saccharomyces cerevisiae exposed to ionizing radiation.

    Science.gov (United States)

    Nishimoto, Takuto; Furuta, Masakazu; Kataoka, Michihiko; Kishida, Masao

    2015-03-01

    Ionizing radiation indirectly causes oxidative stress in cells via reactive oxygen species (ROS), such as hydroxyl radicals (OH(-)) generated by the radiolysis of water. We investigated how the catalase function was affected by ionizing radiation and analyzed the phenotype of mutants with a disrupted catalase gene in Saccharomyces cerevisiae exposed to radiation. The wild-type yeast strain and isogenic mutants with disrupted catalase genes were exposed to various doses of (60)Co gamma-rays. There was no difference between the wild-type strain and the cta1 disruption mutant following exposure to gamma-ray irradiation. In contrast, there was a significant decrease in the ctt1 disruption mutant, suggesting that this strain exhibited decreased survival on gamma-ray exposure compared with other strains. In all three strains, stationary phase cells were more tolerant to the exposure of gamma-rays than exponential phase cells, whereas the catalase activity in the wild-type strain and cta1 disruption mutant was higher in the stationary phase than in the exponential phase. These data suggest a correlation between catalase activity and survival following gamma-ray exposure. However, this correlation was not clear in the ctt1 disruption mutant, suggesting that other factors are involved in the tolerance to ROS induced by irradiation. PMID:25416226

  11. Working Memory Deficits, Increased Anxiety-Like Traits, and Seizure Susceptibility in BDNF Overexpressing Mice

    Science.gov (United States)

    Papaleo, Francesco; Silverman, Jill L.; Aney, Jordan; Tian, Qingjun; Barkan, Charlotte L.; Chadman, Kathryn K.; Crawley, Jacqueline N.

    2011-01-01

    BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher…

  12. Cloning of catalase and expression patterns of catalase and selenium-dependent glutathione peroxidase fromExopalaemon carinicauda in response to low salinity stress

    Institute of Scientific and Technical Information of China (English)

    REN Hai; LI Jian; LI Jitao; YING Yu; GE Hongxing; LI Dongli; YU Tianji

    2015-01-01

    Catalase (CAT) and selenium-dependent glutathione peroxidase (Se-GPx) play a vital role in protecting organisms against various oxidative stresses by eliminating H2O2. The objective of this paper is to evaluate the roles of these antioxidant molecules in the ridgetail white prawnExopalaemon carinicauda in response to low salinity stress. A complementary DNA (cDNA) containing the complete coding sequence of CAT was cloned from the hepatopancreas using reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. The full-length cDNA of CAT (2 649 bp) contains a 5'-untranslated region (UTR) of 78 bp, a 3'- UTR of 1 017 bp, with a poly (A) tail, and an open reading frame of 1 554 bp encoding a 517-amino-acid polypeptide with predicted molecular mass of 58.46 kDa and estimated isoelectric point of 6.64. This CAT sequence contained the proximal active site signature (60FDRERIPERVVHAKGAG76), proximal heme-ligand signature sequence (350RLFSYPDTH358) and three catalytic amino acid residues (His71, Asn144 and Tyr354). Sequence comparison showed that the CAT deduced amino acid sequence ofE.carinicauda shared 68%-92% of identities with those of other species. Quantitative real-time PCR analysis revealed that CAT mRNA was widely expressed in the hepatopancreas (highest), hemocyte, eyestalk, heart, gill, muscle, ovary and stomach. Under low salinity stress, CAT and GPx mRNA expression levels both in the gill and hepatopancreas increased significantly at the first 48 h and 6 h respectively, indicating a tissue- and time-dependent antioxidant response inE.carinicauda. All these results indicate thatE.carinicauda CAT is a member of the CAT family and might be involved in the acute response against low salinity stress.

  13. Tratamento pós-menopausa reduz a atividade da catalase e atenua o risco cardiovascular

    Directory of Open Access Journals (Sweden)

    Vera S. Castanho

    2012-11-01

    Full Text Available FUNDAMENTO: A menopausa pode levar a alterações na saúde feminina, com mudanças no estado oxidativo de mulheres pós-menopausadas, para as quais são limitadas as informações relativas à influência da hormonioterapia (HT sobre as atividades das enzimas antioxidantes. OBJETIVO: Avaliar a influência da HT sobre a atividade da catalase, concentrações de lipídeos e lipoproteínas, proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, nitratos, proteína C-reativa ultrassensível e espessura da carótida em mulheres pós-menopausadas. MÉTODOS: Foram alocadas 94 mulheres para um de quatro grupos com ou sem HT. O último grupo foi subdividido em mulheres sendo tratadas com estrógeno e outras com estrógeno mais progestágeno. Foram realizadas medidas de parâmetros bioquímicos plasmáticos e da espessura da íntima-média da carótida. RESULTADOS: A HT antagonizou a redução na atividade da catalase após a menopausa, mas não teve efeito sobre os níveis da proteína de transferência de colesteril éster, substâncias reativas ao ácido tiobarbitúrico, peróxido lipídico, nitrato e proteína C reativa ultrassensível, nem sobre a espessura da íntima-média da carótida. A análise multivariada mostrou que a HT baseada em estrógeno atenuou a relação entre os fatores de risco cardiovasculares e a espessura da íntima-média da carótida comum. CONCLUSÃO: Este estudo mostra que a HT em mulheres pós-menopausadas produz efeitos antioxidantes e antiateroscleróticos benéficos por melhorar as concentrações séricas de lipídios e lipoproteínas, aumentar a atividade da catalase sérica e atenuar a associação entre os fatores de risco cardiovasculares e a aterosclerose precoce.

  14. Effect of γ-radiation on the activities of superoxide dimutase, catalase and peroxidase on the germinating wheat grain (Triticum aestivum,L.)

    International Nuclear Information System (INIS)

    Effect of γ-radiation on several enzymes like catalase, peroxidase and superoxide dismutase in different parts of germinating wheat seeds has been studied. It was found that superoxide dismutase activity under the influence of γ-radiation was highest in the embryo part and showed maximum activity, 24 hours after germination. The activity exhibited a gradual decline with time. catalase and peroxidase, the stimulatory efect being maximum in the case of catalase activity. The catalase and peroxidase activities were found to be maximally localised in the embryo part and the highest value was attained after 72 hrs. in the case of catalase and after 48 hrs in the case of peroxidase activity. The results indicate that γ-radiation stimulates free radical generation in the embryo along with subsequent increase in the activities of superoside dismutase, catalase and peroxidase. (author)

  15. Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

    International Nuclear Information System (INIS)

    Monoclinic (P21) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å. Catalase (EC 1.11.1.6) catalyses the breakdown of hydrogen peroxide to water and molecular oxygen. Recombinant Vibrio salmonicida catalase (VSC) possesses typical cold-adapted features, with higher catalytic efficiency, lower thermal stability and a lower temperature optimum than its mesophilic counterpart from Proteus mirabilis. Crystals of VSC were produced by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belong to the monoclinic space group P21, with unit-cell parameters a = 98.15, b = 217.76, c = 99.28 Å, β = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit

  16. Crystallization and preliminary X-ray analysis of a bifunctional catalase-phenol oxidase from Scytalidium thermophilum

    International Nuclear Information System (INIS)

    The bifunctional enzyme catalase-phenol oxidase from S. thermophilum was crystallized by the hanging-drop vapour-diffusion method in space group P21 and diffraction data were collected to 2.8 Å resolution. Catalase-phenol oxidase from Scytalidium thermophilum is a bifunctional enzyme: its major activity is the catalase-mediated decomposition of hydrogen peroxide, but it also catalyzes phenol oxidation. To understand the structural basis of this dual functionality, the enzyme, which has been shown to be a tetramer in solution, has been purified by anion-exchange and gel-filtration chromatography and has been crystallized using the hanging-drop vapour-diffusion technique. Streak-seeding was used to obtain larger crystals suitable for X-ray analysis. Diffraction data were collected to 2.8 Å resolution at the Daresbury Synchrotron Radiation Source. The crystals belonged to space group P21 and contained one tetramer per asymmetric unit

  17. Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

    Energy Technology Data Exchange (ETDEWEB)

    Riise, Ellen Kristin [The Norwegian Structural Biology Centre, Faculty of Science, University of Tromsø, N-9037 Tromsø (Norway); Lorentzen, Marit Sjo [Department of Molecular Biotechnology, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, N-9037 Tromsø (Norway); Helland, Ronny [The Norwegian Structural Biology Centre, Faculty of Science, University of Tromsø, N-9037 Tromsø (Norway); Willassen, Nils Peder, E-mail: nilspw@fagmed.uit.no [The Norwegian Structural Biology Centre, Faculty of Science, University of Tromsø, N-9037 Tromsø (Norway); Department of Molecular Biotechnology, Institute of Medical Biology, Faculty of Medicine, University of Tromsø, N-9037 Tromsø (Norway)

    2006-01-01

    Monoclinic (P2{sub 1}) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å. Catalase (EC 1.11.1.6) catalyses the breakdown of hydrogen peroxide to water and molecular oxygen. Recombinant Vibrio salmonicida catalase (VSC) possesses typical cold-adapted features, with higher catalytic efficiency, lower thermal stability and a lower temperature optimum than its mesophilic counterpart from Proteus mirabilis. Crystals of VSC were produced by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 98.15, b = 217.76, c = 99.28 Å, β = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit.

  18. Potentiometric measurement of glucose concentration with an immobilized glucose oxidase/catalase electrode.

    Science.gov (United States)

    Wingard, L B; Liu, C C; Wolfson, S K; Yao, S J; Drash, A L

    1982-01-01

    A series of enzyme electrodes for measurement of glucose have been constructed. The electrodes contain glucose oxidase immobilized on platinum, either with or without co-immobilization of catalase. When placed in buffered glucose, the enzyme electrodes show a potentiometric response to glucose with respect to a Ag/AgCl reference electrode. This response is reproducible in the physiologic range of glucose concentrations. The immobilization technique, some of the environmental variables such as oxygen concentration and pH, and several compounds that might interfere with the selectivity of the enzyme electrodes for glucose have received preliminary study. This direct potentiometric approach is undergoing further evaluation to determine the basic electrochemical mechanism responsible for the potentiometric signal and whether it can be adapted for continuous in vivo monitoring of the glucose concentration in body fluids. PMID:7172983

  19. Simultaneous co-immobilization of glucose oxidase and catalase in their substrates.

    Science.gov (United States)

    Ozyilmaz, G; Tukel, S S

    2007-01-01

    Glucose oxidase (GOD) and catalase (CAT) were simultaneously co-immobilized onto magnesium silicate (florisil) by covalent coupling. Glucose was added in immobilization mixture and hydrogen peroxide which is the substrate of CAT was produced in coupling mixture during immobilization time. Therefore, co-immobilization of GOD and CAT was carried out in presence of both their substrate: glucose and hydrogen peroxide, respectively. The effect of glucose concentration in immobilization mixture on activities of GOD and CAT of co-immobilized samples were investigated. Maximum GOD and CAT activities were determined for samples co-immobilized in presence of 15 and 20 mM glucose, respectively. Co-immobilization of GOD and CAT in presence of their substrates highly improved the activity and reusability of both enzymes. PMID:17345856

  20. Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

    Science.gov (United States)

    Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

    1988-01-01

    The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

  1. The catalase gene family in cucumber: genome-wide identification and organization

    Science.gov (United States)

    Hu, Lifang; Yang, Yingui; Jiang, Lunwei; Liu, Shiqiang

    2016-01-01

    Abstract Catalase (CAT) is a common antioxidant enzyme in almost all living organisms. Currently, detailed reports on cucumber (Cucumis sativus L.) CAT (CsCAT) genes and tissue expression profiling are limited. In the present study, four candidate CsCAT genes were identified in cucumber. Phylogenetic analysis indicated that CsCAT1-CsCAT3 are closely related to Arabidopsis AtCAT1-AtCAT3, but no obvious counterpart was observed for CsCAT4. Intron/exon structure analysis revealed that only one of the 15 positions was completely conserved. Motif analysis showed that, unlike the CAT genes of other species, none of CsCAT genes contained all 10 motifs. Expression data showed that transcripts of all of the CsCAT genes, except CsCAT4, were detected in five tissues. Moreover, their transcription levels displayed differences under different stress treatments. PMID:27560990

  2. Isolation and characterization of a novel catalase-negative, urease-positive Campylobacter from cattle faeces

    DEFF Research Database (Denmark)

    Atabay, H.I.; Corry, J.E.L.; On, S.L.W.

    1997-01-01

    Forty-four strains of a phenotypically unique Campylobacter were isolated from the faeces of 26 of 45 cows in a single herd. Isolation involved enrichment and membrane filtration onto blood agar or plating onto cefoperazone amphotericin teicoplanin agar. The strains exhibited phenotypic character......Forty-four strains of a phenotypically unique Campylobacter were isolated from the faeces of 26 of 45 cows in a single herd. Isolation involved enrichment and membrane filtration onto blood agar or plating onto cefoperazone amphotericin teicoplanin agar. The strains exhibited phenotypic...... characteristics typical for Campylobacter species. However, they were unusual in that they produced urease and copious H2S in triple sugar iron (TSI) medium, but did not produce catalase. They did not grow aerobically. None of the strains grew on modified cefoperazone charcoal deoxycholate agar (m...

  3. [Use of cadmium hydroxide gel for isolation of extracellular catalases from Penicillium piceum and characterization of purified enzymes].

    Science.gov (United States)

    Eremin, A N; Moroz, I V; Mikhaĭlova, R V

    2008-01-01

    We optimized the conditions for isolation of extracellular catalases from Penicillium piceum F-648 and P. piceum A3 by means of volume chromatography with cadmium hydroxide gel. Our study showed that 55-57 mg wet gel are sufficient for the maximum sorption of catalase from 1 ml of culture fluid. This gel was formed in 1 ml 70 mM Cd(NO3)2 after addition of NaOH (Cd(NO3)2/NaOH molar ratio 1:2.2). The eluting solution contained 50 mM NaH2PO4 (pH 7.0), 5.0 mM dithiothreitol, and 0.3% sodium cholate and was potent in desorbing catalase from the gel. Subsequent ultrafiltration of the eluate on the membrane with a retention limit of 50 kDa allowed us to concentrate and purify the sample from low-molecular-weight protein impurities. NH4Cl (1.0 M) containing 0.3% sodium cholate was used to wash the sample from low-molecular-weight aromatic metabolites. Purified catalases included 33-34% antiparallel beta-structures and 9% alpha-spirals. Under optimal conditions in the medium of 10 mM phosphate buffered saline (pH 7.0) at 30 degrees C, catalases from P. piceum F-648 were characterized by the following parameters: K(M), 158.8 mM; catalytic constant, 2.83 x 10(6) s(-1); enzyme inactivation rate constant in H2O2 decomposition, 3.5 x 10(-2) s(-1); and constant of the interaction between catalase complex I and second molecule of H2O2, 1.8 x 10(7) M(-1) s(-1). PMID:19145972

  4. Investigation on the toxic interaction of superparamagnetic iron oxide nanoparticles with catalase

    International Nuclear Information System (INIS)

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for various applications in targeted drug delivery and magnetic resonance imaging. Given their clinical relevance, there is a need to understand these particles' potential cytotoxic effects and possible mechanisms of cytotoxicity. Using a variety of spectroscopic techniques, we investigated the interaction of SPIONs with catalase (CAT) in an aqueous environment. Catalase is an important enzyme that protects cells and tissues from oxidative damage by reactive oxygen species (ROS). Therefore, in this work, CAT served as a model protein for examining the physiological effects of SPIONs due to is function in eliminating H2O2. Synchronous fluorescence spectroscopy results showed that SPIONs have little effect on tryptophan residues in CAT. Data from circular dichroism (CD) and UV–vis spectroscopies showed that CAT α-helical content decreased from 32.4% to 29.1% in the presence of SPIONs. Moreover, a ca. 10% decrease in CAT activity was observed in the presence of SPIONs at a 20:1 particle:protein ratio. These results show that SPIONs can interact with proteins to alter both their structure and function. Further studies with CAT or other toxicologically relevant enzymes may be used for elucidating the mechanisms of SPION cytotoxicity. - Highlights: • This work established the binding mode of SPIONs with CAT on molecular level. • The interaction mechanism was explored by multiple spectroscopic techniques. • SPIONs can loosen the skeleton of protein and increase the exposure of amide moieties in the hydrophobic pocket. • SPIONs can inhibit CAT activity and trigger conformational changes in CAT

  5. Francisella tularensis Catalase Restricts Immune Function by Impairing TRPM2 Channel Activity.

    Science.gov (United States)

    Shakerley, Nicole L; Chandrasekaran, Akshaya; Trebak, Mohamed; Miller, Barbara A; Melendez, J Andrés

    2016-02-19

    As an innate defense mechanism, macrophages produce reactive oxygen species that weaken pathogens and serve as secondary messengers involved in immune function. The Gram-negative bacterium Francisella tularensis utilizes its antioxidant armature to limit the host immune response, but the mechanism behind this suppression is not defined. Here we establish that F. tularensis limits Ca(2+) entry in macrophages, thereby limiting actin reorganization and IL-6 production in a redox-dependent fashion. Wild type (live vaccine strain) or catalase-deficient F. tularensis (ΔkatG) show distinct profiles in their H2O2 scavenging rates, 1 and 0.015 pm/s, respectively. Murine alveolar macrophages infected with ΔkatG display abnormally high basal intracellular Ca(2+) concentration that did not increase further in response to H2O2. Additionally, ΔkatG-infected macrophages displayed limited Ca(2+) influx in response to ionomycin, as a result of ionophore H2O2 sensitivity. Exogenously added H2O2 or H2O2 generated by ΔkatG likely oxidizes ionomycin and alters its ability to transport Ca(2+). Basal increases in cytosolic Ca(2+) and insensitivity to H2O2-mediated Ca(2+) entry in ΔkatG-infected cells are reversed by the Ca(2+) channel inhibitors 2-aminoethyl diphenylborinate and SKF-96365. 2-Aminoethyl diphenylborinate but not SKF-96365 abrogated ΔkatG-dependent increases in macrophage actin remodeling and IL-6 secretion, suggesting a role for H2O2-mediated Ca(2+) entry through the transient receptor potential melastatin 2 (TRPM2) channel in macrophages. Indeed, increases in basal Ca(2+), actin polymerization, and IL-6 production are reversed in TRPM2-null macrophages infected with ΔkatG. Together, our findings provide compelling evidence that F. tularensis catalase restricts reactive oxygen species to temper macrophage TRPM2-mediated Ca(2+) signaling and limit host immune function. PMID:26679996

  6. Investigation on the toxic interaction of superparamagnetic iron oxide nanoparticles with catalase

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zehua [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Liu, Hongwei [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Hu, Xinxin; Song, Wei [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Liu, Rutao, E-mail: rutaoliu@sdu.edu.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China)

    2015-03-15

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for various applications in targeted drug delivery and magnetic resonance imaging. Given their clinical relevance, there is a need to understand these particles' potential cytotoxic effects and possible mechanisms of cytotoxicity. Using a variety of spectroscopic techniques, we investigated the interaction of SPIONs with catalase (CAT) in an aqueous environment. Catalase is an important enzyme that protects cells and tissues from oxidative damage by reactive oxygen species (ROS). Therefore, in this work, CAT served as a model protein for examining the physiological effects of SPIONs due to is function in eliminating H{sub 2}O{sub 2}. Synchronous fluorescence spectroscopy results showed that SPIONs have little effect on tryptophan residues in CAT. Data from circular dichroism (CD) and UV–vis spectroscopies showed that CAT α-helical content decreased from 32.4% to 29.1% in the presence of SPIONs. Moreover, a ca. 10% decrease in CAT activity was observed in the presence of SPIONs at a 20:1 particle:protein ratio. These results show that SPIONs can interact with proteins to alter both their structure and function. Further studies with CAT or other toxicologically relevant enzymes may be used for elucidating the mechanisms of SPION cytotoxicity. - Highlights: • This work established the binding mode of SPIONs with CAT on molecular level. • The interaction mechanism was explored by multiple spectroscopic techniques. • SPIONs can loosen the skeleton of protein and increase the exposure of amide moieties in the hydrophobic pocket. • SPIONs can inhibit CAT activity and trigger conformational changes in CAT.

  7. Role of glutathione redox cycle and catalase in defense against oxidative stress induced by endosulfan in adrenocortical cells of rainbow trout (Oncorhynchus mykiss)

    International Nuclear Information System (INIS)

    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 GSH redox cycle in protection against the adrenal toxicity of endosulfan, a pesticide that impairs cell viability (LC50 366 μM) and cortisol secretion (EC50 19 μM) in a concentration-related manner. Pretreatment with ATA and L-BSO enhanced the toxicity of endosulfan (LC50 and EC50, respectively, 302 and 2.6 μM with ATA, 346 and 3.1 μM with L-BSO), while pretreatment with NAC had no significant effect on cell viability and increased the EC50 of endosulfan to 51 μM. CAT activity was significantly reduced following exposure to endosulfan when cells were pretreated with ATA. Pretreatment with L-BSO significantly decreased glutathione peroxidase (GPx) activity and reduced glutathione (GSH) levels in a concentration-related manner following exposure to endosulfan, while GSH levels were significantly higher in NAC pretreated cells compared to untreated cells. Finally, pretreatment with ATA and L-BSO increased, while pretreatment with NAC decreased, lipid hydroperoxides (LOOH) levels. CAT, GPx, and GSH were identified as important antioxidants in maintaining the function and integrity of rainbow trout adrenocortical cells and ATA, L-BSO, and NAC were identified as effective modulators of CAT and GSH redox cycle. Moreover, this study suggests that the glutathione redox cycle may be more efficient than catalase in protecting adrenocortical cells against endosulfan-induced oxidative stress

  8. Atividade da catalase e da lactato desidrogenase em tilápias submetidas a estresse de confinamento: efeito da cor do ambiente Catalase and lactate dehydrogenase activity in tilapia subjected to contention stress: effect of the background color

    Directory of Open Access Journals (Sweden)

    Elyara Maria Pereira-da-Silva

    2012-05-01

    Full Text Available Avaliaram-se os efeitos da cor do ambiente sobre o crescimento e a atividade da enzima antioxidante catalase (CAT e da lactato desidrogenase (LDH em tilápias do Nilo (n=24; 36,2±3,6g. Oito exemplares foram mortos para determinação da atividade basal das enzimas e os demais permaneceram isolados durante 14 dias sob espectro de luz branca ou azul (n=8 peixes/tratamento. A seguir os peixes foram submetidos a um estresse diário de confinamento de 90 minutos (15° ao 28° dia e pesados semanalmente para cálculo da taxa de crescimento específico (TCE. A TCE negativa confirmou que o confinamento provocou estresse nos peixes, independentemente da cor do ambiente. O aumento da atividade da LDH no músculo vermelho dos peixes mantidos sob luz branca ou azul indicou mudança do metabolismo aeróbio para anaeróbio. O estresse reduziu a atividade da CAT no músculo branco dos peixes mantidos sob a luz branca ou azul. Na musculatura vermelha, esta redução ocorreu apenas nos animais mantidos sob a luz branca. O confinamento aumenta os processos metabólicos anaeróbios e é adequado para estudos sobre os efeitos do estresse. O espectro de luz azul não evita a redução do crescimento e a demanda energética anaeróbia em situações de estresse, mas preserva a atividade da CAT, contribuindo para o bem-estar da tilápia.We assess the effects of the background color on the growth and antioxidant enzyme catalase (CAT and lactate dehydrogenase (LDH in Nile tilapia (n=24; 36.2±3.6g. Eight fish were killed for assessment of basal activity of the enzymes and the others remained isolated for 14 days under white or blue light spectrum (n=8 fish/treatment. Then each animal were subjected to a daily stress of confinement of 90 minutes (15th to 28th day and weighed to calculate the specific growth rate (SGR. The negative SGR confirmed that the confinement stressed in fish, regardless of the background color. The increased activity of LDH in red muscle of fish

  9. Overexpressed TP73 induces apoptosis in medulloblastoma

    Directory of Open Access Journals (Sweden)

    Perlaky Laszlo

    2007-07-01

    Full Text Available Abstract Background Medulloblastoma is the most common malignant brain tumor of childhood. Children who relapse usually die of their disease, which reflects resistance to radiation and/or chemotherapy. Improvements in outcome require a better understanding of the molecular basis of medulloblastoma growth and treatment response. TP73 is a member of the TP53 tumor suppressor gene family that has been found to be overexpressed in a variety of tumors and mediates apoptotic responses to genotoxic stress. In this study, we assessed expression of TP73 RNA species in patient tumor specimens and in medulloblastoma cell lines, and manipulated expression of full-length TAp73 and amino-terminal truncated ΔNp73 to assess their effects on growth. Methods We analyzed medulloblastoma samples from thirty-four pediatric patients and the established medulloblastoma cell lines, Daoy and D283MED, for expression of TP73 RNA including the full-length transcript and the 5'-terminal variants that encode the ΔNp73 isoform, as well as TP53 RNA using quantitative real time-RTPCR. Protein expression of TAp73 and ΔNp73 was quantitated with immunoblotting methods. Clinical outcome was analyzed based on TP73 RNA and p53 protein expression. To determine effects of overexpression or knock-down of TAp73 and ΔNp73 on cell cycle and apoptosis, we analyzed transiently transfected medulloblastoma cell lines with flow cytometric and TUNEL methods. Results Patient medulloblastoma samples and cell lines expressed full-length and 5'-terminal variant TP73 RNA species in 100-fold excess compared to non-neoplastic brain controls. Western immunoblot analysis confirmed their elevated levels of TAp73 and amino-terminal truncated ΔNp73 proteins. Kaplan-Meier analysis revealed trends toward favorable overall and progression-free survival of patients whose tumors display TAp73 RNA overexpression. Overexpression of TAp73 or ΔNp73 induced apoptosis under basal growth conditions in vitro and

  10. Behavioral decline and premature lethality upon pan-neuronal ferritin overexpression in Drosophila infected with a virulent form of Wolbachia.

    Science.gov (United States)

    Kosmidis, Stylianos; Missirlis, Fanis; Botella, Jose A; Schneuwly, Stephan; Rouault, Tracey A; Skoulakis, Efthimios M C

    2014-01-01

    Iron is required for organismal growth. Therefore, limiting iron availability may be a key part of the host's innate immune response to various pathogens, for example, in Drosophila infected with Zygomycetes. One way the host can transiently reduce iron bioavailability is by ferritin overexpression. To study the effects of neuronal-specific ferritin overexpression on survival and neurodegeneration we generated flies simultaneously over-expressing transgenes for both ferritin subunits in all neurons. We used two independent recombinant chromosomes bearing UAS-Fer1HCH, UAS-Fer2LCH transgenes and obtained qualitatively different levels of late-onset behavioral and lifespan declines. We subsequently discovered that one parental strain had been infected with a virulent form of the bacterial endosymbiont Wolbachia, causing widespread neuronal apoptosis and premature death. This phenotype was exacerbated by ferritin overexpression and was curable by antibiotic treatment. Neuronal ferritin overexpression in uninfected flies did not cause evident neurodegeneration but resulted in a late-onset behavioral decline, as previously reported for ferritin overexpression in glia. The results suggest that ferritin overexpression in the central nervous system of flies is tolerated well in young individuals with adverse manifestations appearing only late in life or under unrelated pathophysiological conditions. PMID:24772084

  11. Behavioral decline and premature lethality upon pan-neuronal ferritin overexpression in Drosophila infected with a virulent form of Wolbachia.

    Directory of Open Access Journals (Sweden)

    FanisMissirlis

    2014-04-01

    Full Text Available Iron is required for organismal growth. Therefore, limiting iron availability may be a key part of the host’s innate immune response to various pathogens, for example in Drosophila infected with Zygomycetes. One way the host can transiently reduce iron bioavailability is by ferritin overexpression. To study the effects of neuronal-specific ferritin overexpression on survival and neurodegeneration we generated flies simultaneously over-expressing transgenes for both ferritin subunits in all neurons. We used two independent recombinant chromosomes bearing UAS-Fer1HCH, UAS-Fer2LCH transgenes and obtained qualitatively different levels of late-onset behavioral and lifespan declines. We subsequently discovered that one parental strain had been infected with a virulent form of the bacterial endosymbiont Wolbachia, causing widespread neuronal apoptosis and premature death. This phenotype was exacerbated by ferritin overexpression and was curable by antibiotic treatment. Neuronal ferritin overexpression in uninfected flies did not cause evident neurodegeneration but resulted in a late-onset behavioral decline, as previously reported for ferritin overexpression in glia. The results suggest that ferritin overexpression in the central nervous system of flies is tolerated well in young individuals with adverse manifestations appearing only late in life or under unrelated pathophysiological conditions.

  12. Nucleophosmin is overexpressed in thyroid tumors

    International Nuclear Information System (INIS)

    Nucleophosmin (NPM) is a protein that contributes to several cell functions. Depending on the context, it can act as an oncogene or tumor suppressor. No data are available on NPM expression in thyroid cells. In this work, we analyzed both NPM mRNA and protein levels in a series of human thyroid tumor tissues and cell lines. By using immunohistochemistry, NPM overexpression was detected in papillary, follicular, undifferentiated thyroid cancer, and also in follicular benign adenomas, indicating it as an early event during thyroid tumorigenesis. In contrast, various levels of NPM mRNA levels as detected by quantitative RT-PCR were observed in tumor tissues, suggesting a dissociation between protein and transcript expression. The same behavior was observed in the normal thyroid FRTL5 cell lines. In these cells, a positive correlation between NPM protein levels, but not mRNA, and proliferation state was detected. By using thyroid tumor cell lines, we demonstrated that such a post-mRNA regulation may depend on NPM binding to p-Akt, whose levels were found to be increased in the tumor cells, in parallel with reduction of PTEN. In conclusion, our present data demonstrate for the first time that nucleophosmin is overexpressed in thyroid tumors, as an early event of thyroid tumorigenesis. It seems as a result of a dysregulation occurring at protein and not transcriptional level related to an increase of p-Akt levels of transformed thyrocytes.

  13. Multiple abiotic stress tolerance of the transformants yeast cells and the transgenic Arabidopsis plants expressing a novel durum wheat catalase.

    Science.gov (United States)

    Feki, Kaouthar; Kamoun, Yosra; Ben Mahmoud, Rihem; Farhat-Khemakhem, Ameny; Gargouri, Ali; Brini, Faiçal

    2015-12-01

    Catalases are reactive oxygen species scavenging enzymes involved in response to abiotic and biotic stresses. In this study, we described the isolation and functional characterization of a novel catalase from durum wheat, designed TdCAT1. Molecular Phylogeny analyses showed that wheat TdCAT1 exhibited high amino acids sequence identity to other plant catalases. Sequence homology analysis showed that TdCAT1 protein contained the putative calmodulin binding domain and a putative conserved internal peroxisomal targeting signal PTS1 motif around its C-terminus. Predicted three-dimensional structural model revealed the presence of four putative distinct structural regions which are the N-terminal arm, the β-barrel, the wrapping and the α-helical domains. TdCAT1 protein had the heme pocket that was composed by five essential residues. TdCAT1 gene expression analysis showed that this gene was induced by various abiotic stresses in durum wheat. The expression of TdCAT1 in yeast cells and Arabidopsis plants conferred tolerance to several abiotic stresses. Compared with the non-transformed plants, the transgenic lines maintained their growth and accumulated more proline under stress treatments. Furthermore, the amount of H2O2 was lower in transgenic lines, which was due to the high CAT and POD activities. Taken together, these data provide the evidence for the involvement of durum wheat catalase TdCAT1 in tolerance to multiple abiotic stresses in crop plants. PMID:26555900

  14. Catalase activity in Smicridea McLachlan, 1871 (Insecta, Trichoptera collected from natural and altered/impacted streams

    Directory of Open Access Journals (Sweden)

    Cristiane Biasus

    2015-06-01

    Full Text Available Aim: We compare catalase activity in SmicrideaMcLachlan, 1871 (Insecta, Trichoptera collected in natural and agricultural streams and correlates the enzyme pattern with metal content in the water.MethodsOrganisms were collected in sites classified as natural (riparian vegetation in buffer zone and altered/impacted (agricultural land use in drainage area environments, located at Cravo River and Campo River sub-basins (RS, Brazil. Next the collected larvae were identified and used to proteins quantification and catalase activity measure. The concentration of Mg, Cr, Cu, Pb and Cd in the water was determined by atomic absorption spectrometry.ResultsCatalase activity in Smicridea ranged from 1.5 to 6 U, with mean values about 2.63 ± 0.096 U (SEM. The presence of metals was higher in the streams located at agricultural drainage area, except for Mg at the Cravo sub-basin and Cu at the Campo sub-basin. Catalase was higher in Smicridea collected in natural streams as compared to that agriculture streams and was correlated with Pb and Cd levels.ConclusionsThe data showed the potential of this biomarker as a useful tool for complementation of water quality biomonitoring studies using Smicridea as bioindicator.

  15. Herbicidal and antioxidant responses of transgenic rice overexpressing Myxococcus xanthus protoporphyrinogen oxidase.

    Science.gov (United States)

    Jung, Sunyo; Back, Kyoungwhan

    2005-05-01

    We analyzed the herbicidal and antioxidant defense responses of transgenic rice plants that overexpressed the Myxococcus xanthus protoporphyrinogen oxidase gene. Leaf squares of the wild-type incubated with oxyfluorfen were characterized by necrotic leaf lesions and increases in conductivity and malonyldialdehyde levels, whereas transgenic lines M4 and M7 did not show any change with up to 100 microM oxyfluorfen. The wild-type had decreased F(v)/F(m) and produced a high level of H(2)O(2) at 18 h after foliar application of oxyfluorfen, whereas transgenic lines M4 and M7 were unaffected. In response to oxyfluorfen, violaxanthin, beta-carotene, and chlorophylls (Chls) decreased in wild-type plants, whereas antheraxanthin and zeaxanthin increased. Only a slight decline in Chls was observed in transgenic lines at 48 h after oxyfluorfen treatment. Noticeable increases of cytosolic Cu/Zn-superoxide dismutase, peroxidase isozymes 1 and 2, and catalase were observed after at 48 h of oxyfluorfen treatment in the wild-type. Non-enzymatic antioxidants appeared to respond faster to oxyfluorfen-induced photodynamic stress than did enzymatic antioxidants. Protective responses for the detoxification of active oxygen species were induced to counteract photodynamic stress in oxyfluorfen-treated, wild-type plants. However, oxyfluorfen-treated, transgenic plants suffered less oxidative stress, confirming increased herbicidal resistance resulted from dual expression of M. xanthus Protox in chloroplasts and mitochondria. PMID:15890521

  16. Overexpression of phospholipase Dα gene enhances drought and salt tolerance of Populus tomentosa

    Institute of Scientific and Technical Information of China (English)

    ZHANG TingTing; SONG YunZhi; LIU YuDong; GUO XingQi; ZHU ChangXiang; WEN FuJiang

    2008-01-01

    The cDNA of AtPLDα (Arabidopsis thaliana Phospholipase Da) gene was introduced into P. tomentosa (Populus tomentosa) under the control of the Cauliflower mosaic virus 35S promoter. Southern and Northern blot analyses suggested that the AtPLDα gene has been transferred into the P. tomentosa genome. No obvious morphological or developmental difference was observed between the transgenic and wild-type (WT) plants. Drought and salt tolerance and gene expression of seedlings of several transgenic lines and WT plants (control) were studied. The results showed that the rhizogenesis rate and the average root-length of transgenic lines were significantly higher than WT plants after mannitol and NaCl treatment under the same growth conditions. Northern blot analysis indicated that the higher the PLDα expression in the transgenic plants, the more tolerant the transgenic plants are to drought and salt treatment. Meanwhile, another group of these transgenic lines and WT plants (control) were treated with PEG6000 and NaCI separately. The contents of chlorophylls and the activities of some antioxidant enzymes (superoxide dismutase, guaiacol peroxidase and catalase) as well as malondialdehyde and relative electrical conductivity were analyzed. Altogether, our results demonstrated that overexpression of the PLDα gene can enhance the drought and salt tolerance in transgenic P. tomentosa plants.

  17. The Effect of cdk- 5 Overexpression and Overactivation on Tau Hyperphosphorylation in Cultured N2a Cells

    Institute of Scientific and Technical Information of China (English)

    CHEN Juan; LI Hong-lian; FENG You-mei; WANG Jian-zhi

    2005-01-01

    Neurofibrillary tangles (NFTs) are one of the neuropathological hallmarks of Alzheimer' s disease (AD) and abnormally hyperphosphorylated tau is the major protein of NFTs. It was reported that cyclin-dependent kinase5 (Cdk-5) could phosphorylate tau at most AD-related epitopes in vivo. In this study, we investigated the effect of cdk-5 overexpression on tau hyperphosphorylation in neuroblastoma N2a cells. We demonstrated that overexpression of cdk-5 which resulted in a 3.5-fold Cdk5 activation in the transfected cells induced a dramatic increase in phosphorylation of tau at several phosphorylation sites. Overexpression of cdk-5 led to a reduced staining with antibody Tau-1 and an enhanced staining with antibody PHF-1, suggesting hy perphosphorylation of tau at Ser199/202 and Ser396/404 sites. It implies that in vitro overexpression of cdk-5 leads to Cdk5 overactivation and tau hyperphosphorylation may be the underline mechanism.

  18. Improved photosynthetic performance during severe drought in Nicotiana tabacum overexpressing a nonenergy conserving respiratory electron sink.

    Science.gov (United States)

    Dahal, Keshav; Martyn, Greg D; Vanlerberghe, Greg C

    2015-10-01

    Chloroplasts have means to manage excess reducing power but these mechanisms may become restricted by rates of ATP turnover. Alternative oxidase (AOX) is a mitochondrial terminal oxidase that uncouples the consumption of reducing power from ATP synthesis. Physiological and biochemical analyses were used to compare respiration and photosynthesis of Nicotiana tabacum wild-type (WT) plants with that of transgenic lines overexpressing AOX, under both well-watered and drought stress conditions. With increasing drought severity, AOX overexpression acted to increase respiration in the light (RL ) relative to WT. CO2 and light response curves indicated that overexpression also improved photosynthetic performance relative to WT, as drought severity increased. This was not due to an effect of AOX amount on leaf water status or the development of the diffusive limitations that occur due to drought. Rather, AOX overexpression dampened photosystem stoichiometry adjustments and losses of key photosynthetic components that occurred in WT. The results indicate that AOX amount influences RL , particularly during severe drought, when cytochrome pathway respiration may become increasingly restricted. This impacts the chloroplast redox state, influencing how the photosynthetic apparatus responds to increasing drought severity. In particular, the development of biochemical limitations to photosynthesis are dampened in plants with increased nonenergy conserving RL . PMID:26032897

  19. Overexpression of ABCG1 protein attenuates arteriosclerosis and endothelial dysfunction in atherosclerotic rabbits

    Directory of Open Access Journals (Sweden)

    Martin Ungerer

    2012-06-01

    Full Text Available The ABCG1 protein is centrally involved in reverse cholesterol transport from the vessel wall. Investigation of the effects of ABCG1 overexpression or knockdown in vivo has produced controversial results and strongly depended on the gene intervention model in which it was studied. Therefore, we investigated the effect of local overexpression of human ABCG1 in a novel model of vessel wall-directed adenoviral gene transfer in atherosclerotic rabbits. We conducted local, vascular-specific gene transfer by adenoviral delivery of human ABCG1 (Ad-ABCG1-GFP in cholesterol-fed atherosclerotic rabbits in vivo. Endothelial overexpression of ABCG1 markedly reduced atheroprogression (plaque size and almost blunted vascular inflammation, as shown by markedly reduced macrophage and smooth muscle cell invasion into the vascular wall. Also endothelial function, as determined by vascular ultrasound in vivo, was improved in rabbits after gene transfer with Ad-ABCG1-GFP. Therefore, both earlier and later stages of atherosclerosis were improved in this model of somatic gene transfer into the vessel wall. In contrast to results in transgenic mice, overexpression of ABCG1 by somatic gene transfer to the atherosclerotic vessel wall results in a significant improvement of plaque morphology and composition, and of vascular function in vivo.

  20. Matrix-Dependent Regulation of AKT in Hepsin-Overexpressing PC3 Prostate Cancer Cells12

    Science.gov (United States)

    Wittig-Blaich, Stephanie M; Kacprzyk, Lukasz A; Eismann, Thorsten; Bewerunge-Hudler, Melanie; Kruse, Petra; Winkler, Eva; Strauss, Wolfgang S L; Hibst, Raimund; Steiner, Rudolf; Schrader, Mark; Mertens, Daniel; Sültmann, Holger; Wittig, Rainer

    2011-01-01

    The serine-protease hepsin is one of the most prominently overexpressed genes in human prostate carcinoma. Forced expression of the enzyme in mice prostates is associated with matrix degradation, invasive growth, and prostate cancer progression. Conversely, hepsin overexpression in metastatic prostate cancer cell lines was reported to induce cell cycle arrest and reduction of invasive growth in vitro. We used a system for doxycycline (dox)-inducible target gene expression in metastasis-derived PC3 cells to analyze the effects of hepsin in a quantitative manner. Loss of viability and adhesion correlated with hepsin expression levels during anchorage-dependent but not anchorage-independent growth. Full expression of hepsin led to cell death and detachment and was specifically associated with reduced phosphorylation of AKT at Ser473, which was restored by growth on matrix derived from RWPE1 normal prostatic epithelial cells. In the chorioallantoic membrane xenograft model, hepsin overexpression in PC3 cells reduced the viability of tumors but did not suppress invasive growth. The data presented here provide evidence that elevated levels of hepsin interfere with cell adhesion and viability in the background of prostate cancer as well as other tissue types, the details of which depend on the microenvironment provided. Our findings suggest that overexpression of the enzyme in prostate carcinogenesis must be spatially and temporally restricted for the efficient development of tumors and metastases. PMID:21750652

  1. Matrix-Dependent Regulation of AKT in Hepsin-Overexpressing PC3 Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Stephanie M Wittig-Blaich

    2011-07-01

    Full Text Available The serine-protease hepsin is one of the most prominently overexpressed genes in human prostate carcinoma. Forced expression of the enzyme in mice prostates is associated with matrix degradation, invasive growth, and prostate cancer progression. Conversely, hepsin overexpression in metastatic prostate cancer cell lines was reported to induce cell cycle arrest and reduction of invasive growth in vitro. We used a system for doxycycline (dox-inducible target gene expression in metastasis-derived PC3 cells to analyze the effects of hepsin in a quantitative manner. Loss of viability and adhesion correlated with hepsin expression levels during anchorage-dependent but not anchorage-independent growth. Full expression of hepsin led to cell death and detachment and was specifically associated with reduced phosphorylation of AKT at Ser473, which was restored by growth on matrix derived from RWPE1 normal prostatic epithelial cells. In the chorioallantoic membrane xenograft model, hepsin overexpression in PC3 cells reduced the viability of tumors but did not suppress invasive growth. The data presented here provide evidence that elevated levels of hepsin interfere with cell adhesion and viability in the background of prostate cancer as well as other tissue types, the details of which depend on the microenvironment provided. Our findings suggest that overexpression of the enzyme in prostate carcinogenesis must be spatially and temporally restricted for the efficient development of tumors and metastases.

  2. Amelioration of radiation induced decrease in activity of catalase and superoxide dismutase in mouse liver by Punica granatum

    International Nuclear Information System (INIS)

    Ionizing radiation generates reactive oxygen species (ROS) in irradiated tissue. Cells of liver have their own defence system, the antioxidant system to deactivate ROS. Antioxidant system includes enzymatic and non-enzymatic components. Liver is rich in endogenous antioxidants and related enzymes. Catalase and Superoxide dismutase (SOD) are powerful antioxidant enzymes. In the present study Punica granatum fruit rind Ethanol extract (PGFRE) was tested against 60Co gamma radiation induced alteration in Swiss albino mouse. Healthy adult (25±2) Swiss albino mouse were selected and divided into four groups. The first group was sham irradiated. The second group was irradiated with 8 Gy 60Co gamma radiation only and served as control. The third group was administered with Ethanol extract of Punica granatum fruit rind one hour before irradiation at the dose rate of 10 mg/kg body weight orally. Animals were exposed to 8 Gy 60Co gamma radiation. Fourth group was administered with Ethanol extract of Punica granatum fruit rind at the dose rate of 10 mg/kg body weight. Mice were sacrificed at various post irradiation intervals and liver was removed, weighed and analysed biochemically for Catalase and SOD activity. Catalase and SOD activity decreased up till 7th post irradiation day in 8 Gy irradiated group than normal. In PGFRE pretreated irradiated group catalase and SOD activity were higher than the corresponding control group at all the intervals. These results indicate that PGFRE extract protects damage to the catalase and SOD activity in liver of Swiss albino mouse against lethal dose of gamma radiation. (author)

  3. Further studies on O2-resistant photosynthesis and photorespiration in a tobacco mutant with enhanced catalase activity

    International Nuclear Information System (INIS)

    The increase in net photosynthesis in M4 progeny of an O2-resistant tobacco (Nicotiana tabacum) mutant relative to wild-type plants at 21 and 42% O2 has been confirmed and further investigated. Self-pollination of an M3 mutant produced M4 progeny segregating high catalase phenotypes (average 40% greater than wild type) at a frequency of about 60%. The high catalase phenotype cosegregated precisely with O2-resistant photosynthesis. About 25% of the F1 progeny of reciprocal crosses between the same M3 mutant and wild type had high catalase activity, whether the mutant was used as the maternal or paternal parent, indicating nuclear inheritance. In high-catalase mutants the activity of NADH-hydroxypyruvate reductase, another peroxisomal enzyme, was the same as wild type. The mutants released 15% less photorespiratory CO2 as a percent of net photosynthesis in CO2-free 21% O2 and 36% less in CO2-free 42% O2 compared with wild type. The mutant leaf tissue also released less 14CO2 per [1-14C]glycolate metabolized than wild type in normal air, consistent with less photorespiration in the mutant. The O2-resistant photosynthesis appears to be caused by a decrease in photorespiration especially under conditions of high O2 where the stoichiometry of CO2 release per glycolate metabolized is expected to be enhanced. The higher catalase activity in the mutant may decrease the nonenzymatic peroxidation of keto-acids such as hydroxypyruvate and glyoxylate by photorespiratory H2O2

  4. 过氧化氢酶与糖尿病的研究进展%Catalase and diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    赵瑞娥; 刘丽梅

    2008-01-01

    Catalase(CAT)can decompose hydrogen peroxide(H2O2),a product of peroxide dismuted by superoxide dismutase,into oxygen and water,so as to reduce the generation of toxic reactive hydroxyl radicals and prevent damage and dysfunction of islet β cells.Previous studies have shown that two polymorphisms,C-262T and C1167T,of CAT gene were significantly associated with diabetes mellitus,and that their C alleles were risk factors of type 1 diabetes mellitus.Moreover,other ethnical studies demonstrated that both genetic defects and pelymorphisms of the CAT gene could reduce the activity of CAT,increase the concentration of the H2O2 and therefore aggravate the oxidative stress.These data suggested that genetic variation of CAT may be an important pathophysiological mechanism in the development of diabetes and its complications.%过氧化氢酶(CAT)能迅速将超氧化物歧化酶分解过氧化物产生的过氧化氢(H2O2)转化为氧气和水,从而减少更具氧化活性的羟自由基生成,防止氧化应激造成的胰岛β细胞损伤和功能异常.研究发现,CAT基因的两个多态位点C-262T及C1167T均与糖尿病发生显著相关,其C等位基因均为1型糖尿病发病的危险因子.此外,其他种族研究证实,CAT的遗传学缺陷及其基因多态性均可引起CAT活性下降,使机体H2O2浓度增加,加重氧化应激.提示CAT的遗传变异可能是促进糖尿病及其并发症发生和发展的重要病理生理机制之一.

  5. Overexpression of Robo2 causes defects in the recruitment of metanephric mesenchymal cells and ureteric bud branching morphogenesis

    International Nuclear Information System (INIS)

    Highlights: ► Overexpression of Robo2 caused reduced UB branching and glomerular number. ► Fewer MM cells surrounding the UB after overexpression of Robo2 in vitro. ► No abnormal Epithelial Morphology of UB or apoptosis of mm cells in the kidney. ► Overexpression of Robo2 affected MM cells migration and caused UB deficit. ► The reduced glomerular number can also be caused by fewer MM cells. -- Abstract: Roundabout 2 (Robo2) is a member of the membrane protein receptor family. The chemorepulsive effect of Slit2–Robo2 signaling plays vital roles in nervous system development and neuron migration. Slit2–Robo2 signaling is also important for maintaining the normal morphogenesis of the kidney and urinary collecting system, especially for the branching of the ureteric bud (UB) at the proper site. Slit2 or Robo2 mouse mutants exhibit multilobular kidneys, multiple ureters, and dilatation of the ureter, renal pelvis, and collecting duct system, which lead to vesicoureteral reflux. To understand the effect of Robo2 on kidney development, we used microinjection and electroporation to overexpress GFP-Robo2 in an in vitro embryonic kidney model. Our results show reduced UB branching and decreased glomerular number after in vitro Robo2 overexpression in the embryonic kidneys. We found fewer metanephric mesenchymal (MM) cells surrounding the UB but no abnormal morphology in the branching epithelial UB. Meanwhile, no significant change in MM proliferation or apoptosis was observed. These findings indicate that Robo2 is involved in the development of embryonic kidneys and that the normal expression of Robo2 can help maintain proper UB branching and glomerular morphogenesis. Overexpression of Robo2 leads to reduced UB branching caused by fewer surrounding MM cells, but MM cell apoptosis is not involved in this effect. Our study demonstrates that overexpression of Robo2 by microinjection in embryonic kidneys is an effective approach to study the function of Robo2.

  6. Focal adhesion kinase overexpression and its impact on human osteosarcoma

    Science.gov (United States)

    Chen, Yong; Yang, Aizhen; Chen, Hui; Zhang, Jian; Wu, Sujia; Shi, Xin; Wang, Chen; Sun, Xiaoliang

    2015-01-01

    Focal adhesion kinase (FAK) has been implicated in tumorigenesis in various malignancies. We sought to examine the expression patterns of FAK and the activated form, phosphorylated FAK (pFAK), in human osteosarcoma and to investigate the correlation of FAK expression with clinicopathologic parameters and prognosis. In addition, the functional consequence of manipulating the FAK protein level was investigated in human osteosarcoma cell lines. Immunohistochemical staining was used to detect FAK and pFAK in pathologic archived materials from 113 patients with primary osteosarcoma. Kaplan-Meier survival and Cox regression analyses were performed to evaluate the prognoses. The role of FAK in the cytological behavior of MG63 and 143B human osteosarcoma cell lines was studied via FAK protein knock down with siRNA. Cell proliferation, migration, invasiveness and apoptosis were assessed using the CCK8, Transwell and Annexin V/PI staining methods. Both FAK and pFAK were overexpressed in osteosarcoma. There were significant differences in overall survival between the FAK-/pFAK- and FAK+/pFAK- groups (P = 0.016), the FAK+/pFAK- and FAK+/pFAK+ groups (P = 0.012) and the FAK-/pFAK- and FAK+/pFAK+ groups (P < 0.001). There were similar differences in metastasis-free survival between groups. The Cox proportional hazards analysis showed that the FAK expression profile was an independent indicator of both overall and metastasis-free survival. siRNA-based knockdown of FAK not only dramatically reduced the migration and invasion of MG63 and 143B cells, but also had a distinct effect on osteosarcoma cell proliferation and apoptosis. These results collectively suggest that FAK overexpression and phosphorylation might predict more aggressive biologic behavior in osteosarcoma and may be an independent predictor of poor prognosis. PMID:26393679

  7. Comparison of catalase immunoreactivity in the hippocampus between young, adult and aged mice and rats.

    Science.gov (United States)

    Ahn, Ji Hyeon; Chen, Bai Hui; Shin, Bich-Na; Lee, Tae-Kyeong; Cho, Jeong Hwi; Kim, In Hye; Park, Joon Ha; Lee, Jae-Chul; Tae, Hyun-Jin; Lee, Choong-Hyun; Won, Moo-Ho; Lee, Yun Lyul; Choi, Soo Young; Hong, Seongkweon

    2016-07-01

    Catalase (CAT) is an important antioxidant enzyme and is crucial in modulating synaptic plasticity in the brain. In this study, CAT expression as well as neuronal distribution was compared in the hippocampus among young, adult and aged mice and rats. Male ICR mice and Sprague Dawley rats were used at postnatal month (PM) 1, PM 6 and PM 24 as the young, adult and aged groups, respectively (n=14/group). CAT expression was examined by immunohistochemistry and western blot analysis. In addition, neuronal distribution was examined by NeuN immunohistochemistry. In the present study, the mean number of NeuN‑immunoreactive neurons was marginally decreased in mouse and rat hippocampi during aging, although this change was not identified to be significantly different. However, CAT immunoreactivity was significantly increased in pyramidal and granule neurons in the adult mouse and rat hippocampi and was significantly decreased in the aged mouse and rat hippocampi compared with that in the young animals. CAT protein levels in the hippocampus were also lowest in the aged mouse and rat hippocampus. These results indicate that CAT expression is significantly decreased in the hippocampi of aged animals and decreased CAT expression may be closely associated with aging. PMID:27221506

  8. Effects of sodium nitroprusside on mouse erythrocyte catalase activity and malondialdehyde status.

    Science.gov (United States)

    Sani, Mamane; Sebai, Hichem; Refinetti, Roberto; Mondal, Mohan; Ghanem-Boughanmi, Néziha; Boughattas, Naceur A; Ben-Attia, Mossadok

    2016-07-01

    There is controversy about the anti- or pro-oxidative effects of the nitric oxide (NO)-donor sodium nitroprusside (SNP). Hence, the activity of the antioxidant enzyme catalase (CAT) and the status of malondialdehyde (MDA) were investigated after a 2.5 mg/kg dose of SNP had been i.p. administered to different and comparable groups of mice (n =  48). The drug was administered at two different circadian times (1 and 13 h after light onset [HALO]). There were, irrespectively of sampling time, no significant differences in the means of CAT activity and MDA status between control and SNP-treated groups, no matter the treatment time. However, CAT activity was significantly (Student's t-test, p analysis of variance (ANOVA) detected a significant (F0.05(7,88)= 5.3; p < 0.0006) interaction between sampling time and treatment in mice injected at 1 HALO, suggesting the influence of treatment on sampling-time-related changes in CAT activity. However, ANOVA validated no interaction between the two factors in mice treated at 13 HALO, illustrating that the sampling-time differences in enzyme activity were greater. Furthermore, two-way ANOVA revealed no interaction in the variation of MDA status in animals treated either at 1 or 13 HALO. This study indicates that SNP significantly affected the anti-oxidant system. PMID:26738972

  9. Molecular Insights into the Potential Toxicological Interaction of 2-Mercaptothiazoline with the Antioxidant Enzyme—Catalase

    Science.gov (United States)

    Huang, Zhenxing; Huang, Ming; Mi, Chenyu; Wang, Tao; Chen, Dong; Teng, Yue

    2016-01-01

    2-mercaptothiazoline (2-MT) is widely used in many industrial fields, but its residue is potentially harmful to the environment. In this study, to evaluate the biological toxicity of 2-MT at protein level, the interaction between 2-MT and the pivotal antioxidant enzyme—catalase (CAT) was investigated using multiple spectroscopic techniques and molecular modeling. The results indicated that the CAT fluorescence quenching caused by 2-MT should be dominated by a static quenching mechanism through formation of a 2-MT/CAT complex. Furthermore, the identifications of the binding constant, binding forces, and the number of binding sites demonstrated that 2-MT could spontaneously interact with CAT at one binding site mainly via Van der Waals’ forces and hydrogen bonding. Based on the molecular docking simulation and conformation dynamic characterization, it was found that 2-MT could bind into the junctional region of CAT subdomains and that the binding site was close to enzyme active sites, which induced secondary structural and micro-environmental changes in CAT. The experiments on 2-MT toxicity verified that 2-MT significantly inhibited CAT activity via its molecular interaction, where 2-MT concentration and exposure time both affected the inhibitory action. Therefore, the present investigation provides useful information for understanding the toxicological mechanism of 2-MT at the molecular level. PMID:27537873

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Nanospherical Brush as Catalase Container for Enhancing the Detection Sensitivity of Competitive Plasmonic ELISA.

    Science.gov (United States)

    Huang, Xiaolin; Chen, Rui; Xu, Hengyi; Lai, Weihua; Xiong, Yonghua

    2016-02-01

    Plasmonic enzyme-linked immunosorbent assay (pELISA) based on catalase (CAT)-mediated gold nanoparticle growth shows great potential for the determination of disease-related biomarkers at ultralow concentrations by using sandwich formats. However, the relatively low sensitivity of this strategy using competitive formats limits its adoption for hapten detection. Herein, we present an improved competitive pELISA for ultrasensitive detection of ochratoxin A (OTA), where silica nanoparticles carrying poly(acrylic acid) brushes (SiO2@PAA) were used to decrease the affinity of competing antigens to anti-OTA monoclonal antibodies and amplify the signal as a "CAT container" (SiO2@PAA@CAT). The developed competitive pELISA exhibits extremely high sensitivity for OTA with detection limits of 10(-18) and 5 × 10(-20) g/mL by the naked eye and microplate reader, respectively. These values are at least 7 orders of magnitude lower than that of competitive CAT-based pELISA (10(-11) g/mL by the naked eye) and 8 orders of magnitude lower than that of horseradish peroxidase-based conventional ELISA (10(-11) g/mL by the microplate reader), respectively. Reliability and robustness of the proposed method were evaluated using actual agricultural products and human serum samples. This study demonstrated the potential of this modified method in practical applications involving the ultrasensitive detection of mycotoxins or other haptens. PMID:26719076

  12. Involvement of catalase in the protective benefits of metformin in mice with oxidative liver injury.

    Science.gov (United States)

    Dai, Jie; Liu, Mingwei; Ai, Qing; Lin, Ling; Wu, Kunwei; Deng, Xinyu; Jing, Yuping; Jia, Mengying; Wan, Jingyuan; Zhang, Li

    2014-06-01

    Metformin is a commonly used anti-diabetic drug with AMP-activated protein kinase (AMPK)-dependent hypoglycemic activities. Recent studies have revealed its anti-inflammatory and anti-oxidative properties. In the present study, the anti-oxidative potential of metformin and its potential mechanisms were investigated in a mouse model with carbon tetrachloride (CCl₂)-induced severe oxidative liver injury. Our results showed that treatment with metformin significantly attenuated CCl₂-induced elevation of serum aminotransferases and hepatic histological abnormalities. The alleviated liver injury was associated with decreased hepatic contents of oxidized glutathione (GSSG) and malondialdehyde (MDA). In addition, metformin treatment dose-dependently enhanced the activities of catalase (CAT) and decreased CCl₄-induced elevation of hepatic H₂O₂ levels, but it had no obvious effects on the protein level of CAT. We also found that metformin increased the level of phosphorylated AMP-activated protein kinase (AMPK), but treatment with AMPK activator AICAR had no obvious effects on CAT activity. A molecular docking analysis indicated that metformin might interact with CAT via hydrogen bonds. These data suggested that metformin effectively alleviated CCl₄-induced oxidative liver injury in mice and these hepatoprotective effects might be associated with CAT. PMID:24717679

  13. Analysis of oxidative stress status, catalase and catechol-O-methyltransferase polymorphisms in Egyptian vitiligo patients.

    Directory of Open Access Journals (Sweden)

    Dina A Mehaney

    Full Text Available Vitiligo is the most common depigmentation disorder of the skin. Oxidative stress is implicated as one of the probable events involved in vitiligo pathogenesis possibly contributing to melanocyte destruction. Evidence indicates that certain genes including those involved in oxidative stress and melanin synthesis are crucial for development of vitiligo. This study evaluates the oxidative stress status, the role of catalase (CAT and catechol-O-Methyltransferase (COMT gene polymorphisms in the etiology of generalized vitiligo in Egyptians. Total antioxidant capacity (TAC and malondialdehyde (MDA levels as well as CAT exon 9 T/C and COMT 158 G/A polymorphisms were determined in 89 patients and 90 age and sex-matched controls. Our results showed significantly lower TAC along with higher MDA levels in vitiligo patients compared with controls. Meanwhile, genotype and allele distributions of CAT and COMT polymorphisms in cases were not significantly different from those of controls. Moreover, we found no association between both polymorphisms and vitiligo susceptibility. In conclusion, the enhanced oxidative stress with the lack of association between CAT and COMT polymorphisms and susceptibility to vitiligo in our patients suggest that mutations in other genes related to the oxidative pathway might contribute to the etiology of generalized vitiligo in Egyptian population.

  14. Effect of phenol on germination capacity and polyphenol oxidase, peroxidase and catalase activities in lettuce

    Directory of Open Access Journals (Sweden)

    Tadić Vojin

    2014-01-01

    Full Text Available In this study we examined the activities of polyphenol oxidase (PPO and antioxidant enzymes, peroxidase (POX and catalase (CAT during lettuce seed germination at different concentrations of phenol. Out of eleven varieties of lettuce, four were chosen according to their germination tolerance to phenol as follows: plants exhibiting high (Ljubljanska ledenka - LJL and Nansen - N and low toleranace (Little Gem - LG and Majska kraljica - MK. A decrease in germination efficiency after exposure to LD50 of phenol was determined for these four varieties. The effects of phenol treatment on POX, CAT and PPO activities were determined after 4, 5, 6, 7 and 8 days of growth at LD50 concentrations. A trend of increased peroxidase activity was observed in seeds grown on LD50 of phenol compared to control seeds. A significant increase in CAT activity was observed at the beginning of treatment for MK, LG and N in seeds grown on phenol as well as in control seeds. A trend of increased PPO activity was observed in all control seeds. We also investigated the affinity of PPO for two different substrates that were used for the determination of enzyme activity. Our results show that LJL and N are the varieties most tolerant to growth on phenol. Here we report on the activities of their antioxidant enzymes and PPO during seed germination. [Projekat Ministarstva nauke Republike Srbije, br. ON173017

  15. Reduction of oxidative cellular damage by overexpression of the thioredoxin TRX2 gene improves yield and quality of wine yeast dry active biomass

    Directory of Open Access Journals (Sweden)

    Ros Joaquim

    2010-02-01

    Full Text Available Abstract Background Wine Saccharomyces cerevisiae strains, adapted to anaerobic must fermentations, suffer oxidative stress when they are grown under aerobic conditions for biomass propagation in the industrial process of active dry yeast production. Oxidative metabolism of sugars favors high biomass yields but also causes increased oxidation damage of cell components. The overexpression of the TRX2 gene, coding for a thioredoxin, enhances oxidative stress resistance in a wine yeast strain model. The thioredoxin and also the glutathione/glutaredoxin system constitute the most important defense against oxidation. Trx2p is also involved in the regulation of Yap1p-driven transcriptional response against some reactive oxygen species. Results Laboratory scale simulations of the industrial active dry biomass production process demonstrate that TRX2 overexpression increases the wine yeast final biomass yield and also its fermentative capacity both after the batch and fed-batch phases. Microvinifications carried out with the modified strain show a fast start phenotype derived from its enhanced fermentative capacity and also increased content of beneficial aroma compounds. The modified strain displays an increased transcriptional response of Yap1p regulated genes and other oxidative stress related genes. Activities of antioxidant enzymes like Sod1p, Sod2p and catalase are also enhanced. Consequently, diminished oxidation of lipids and proteins is observed in the modified strain, which can explain the improved performance of the thioredoxin overexpressing strain. Conclusions We report several beneficial effects of overexpressing the thioredoxin gene TRX2 in a wine yeast strain. We show that this strain presents an enhanced redox defense. Increased yield of biomass production process in TRX2 overexpressing strain can be of special interest for several industrial applications.

  16. Nitric Oxide Synthase Type III Overexpression By Gene Therapy Exerts Antitumoral Activity In Mouse Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Raúl González

    2015-08-01

    Full Text Available Hepatocellular carcinoma develops in cirrhotic liver. The nitric oxide (NO synthase type III (NOS-3 overexpression induces cell death in hepatoma cells. The study developed gene therapy designed to specifically overexpress NOS-3 in cultured hepatoma cells, and in tumors derived from orthotopically implanted tumor cells in fibrotic livers. Liver fibrosis was induced by CCl4 administration in mice. Hepa 1-6 cells were used for in vitro and in vivo experiments. The first generation adenovirus was designed to overexpress NOS-3 (or GFP and luciferase cDNA under the regulation of murine alpha-fetoprotein (AFP and Rous Sarcoma Virus (RSV promoters, respectively. Both adenoviruses were administered through the tail vein two weeks after orthotopic tumor cell implantation. AFP-NOS-3/RSV-Luciferase increased oxidative-related DNA damage, p53, CD95/CD95L expression and caspase-8 activity in cultured Hepa 1-6 cells. The increased expression of CD95/CD95L and caspase-8 activity was abolished by l-NAME or p53 siRNA. The tail vein infusion of AFP-NOS- 3/RSV-Luciferase adenovirus increased cell death markers, and reduced cell proliferation of established tumors in fibrotic livers. The increase of oxidative/nitrosative stress induced by NOS-3 overexpression induced DNA damage, p53, CD95/CD95L expression and cell death in hepatocellular carcinoma cells. The effectiveness of the gene therapy has been demonstrated in vitro and in vivo.

  17. Simultaneous and sequential co-immobilization of glucose oxidase and catalase onto florisil.

    Science.gov (United States)

    Ozyilmaz, Gul; Tukel, S Seyhan

    2007-06-01

    The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against H2O2 inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and 30 degrees C, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both 5 degrees C and 25 degrees C. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by H2O2 and supplying additional O2 to the reaction system. PMID:18050914

  18. Biophysical perspective of the binding of ester-functionalized gemini surfactants with catalase.

    Science.gov (United States)

    Akram, Mohd; Bhat, Imtiyaz Ahmad; Anwar, Sana; Ahmad, Ajaz; Kabir-Ud-Din

    2016-07-01

    Interaction of surfactants with biomacromolecules is an essential subject of biophysical chemistry to address their diverse applications in industry, biomedical, and cosmetic domains. In this context, we have examined the binding interactions of three ester-functionalized surfactants (m-E2-m) with bovine liver catalase (BLC, 10μM) by employing a multi-technique approach. The m-E2-m geminis quench fluorescence intensity of BLC through static procedure. The binding ability of concerned gemini surfactants was found to be in the order 12-E2-12 (Kb=2.3×10(2))>16-E2-16 (Kb=1.1×10(2))>14-E2-14 (Kb=1.0×10(2)). Quenching efficacy, as determined by Ksv values, were observed as 12-E2-12 (3.0×10(2))>16-E2-16 (1.4×10(2))>14-E2-14 (1.0×10(2)). The negative ΔG°b values (12-E2-12 (-13.48kJ/mol)>16-E2-16 (-11.65kJ/mol)>14-E2-14 (-11.41kJ/mol)) indicate spontaneous nature of m-E2-m-BLC interactions. UV-vis spectroscopy, circular dichroism (CD) and micropolarity (F1/F3) assessments indicate conformational changes in BLC upon m-E2-m combination. ITC confirms the stability of BLC upon gemini combination. Docking provides support to fluorescence results by presenting the localization site of m-E2-m surfactants near to aromatic residues (mainly Tyr, Trp and Phe). Moreover, since surfactant-protein interactions have essential miscellaneous implications, therefore, this study can be significant for industrial and biomedical realms. PMID:27060016

  19. Application of different molecular techniques for characterization of catalase-positive cocci isolated from sucuk.

    Science.gov (United States)

    Kesmen, Zülal; Yarimcam, Burcu; Aslan, Hakiye; Ozbekar, Esra; Yetim, Hasan

    2014-02-01

    This study was carried out for the characterization and discrimination of the indigenous Gram positive, catalase-positive cocci (GCC) population in sucuk, a traditional Turkish dry-fermented sausage. Sucuk samples, produced by the traditional method without starter culture were collected from 8 local producers in Kayseri/Turkey and a total of 116 GCC isolates were identified by using different molecular techniques. Two different molecular fingerprinting methods; namely, randomly amplified polymorphic DNA-PCR (RAPD-PCR) and repetitive extragenic palindrome-PCR (rep-PCR), were used for the clustering of isolates and identification at species level was carried out by full length sequencing of 16S rDNA. Combining the results obtained from molecular fingerprinting and 16S rDNA sequencing showed that the dominant GCC species isolated from the sucuk samples was Staphylococcus saprophyticus followed by Staphylococcus succinus and Staphylococcus equorum belonging to the Staphylococcus genus. Real-time PCR DNA melting curve analysis and high-resolution melting (HRM) analysis targeting the V1 + V3 regions of 16S rDNA were also applied for the discrimination of isolates belonging to different species. It was observed statistically different Tm values and species-specific HRM profiles for all except 2 species (S. saprophyticus and Staphylococcus xylosus) that have high 16S rDNA sequence similarity. The combination of rep-PCR and/or PCR-RAPD with 16S rRNA gene sequencing was an efficient approach for the characterization and identification of the GCC population in spontaneously fermented sucuk. On the other hand, intercalating dye assays were found to be a simple and very promising technique for the differentiation of the GCC population at species level. PMID:24410408

  20. Catalase inhibition accelerates dormancy release and sprouting in potato (Solanum tuberosum L. tubers

    Directory of Open Access Journals (Sweden)

    Mohammed Bajji

    2007-01-01

    Full Text Available The involvement of hydrogen peroxide (H2O2 metabolism in dormancy release and sprouting of potato (Solanum tuberosum L. tubers has been investigated using three complementary approaches. In the first approach, the evolution of the sprouting kinetics, H2O2 content and antioxidant enzyme activities were examined during tuber storage. The most important changes occurred at the « bud/sprout » level. In particular, dormancy release was accompanied by a transient but remarkable increase in H2O2 content. In the second approach, the effect of a catalase (CAT, EC 1.11.1.6 inhibitor (thiourea or of exogenous H2O2 application on tuber sprouting behaviour was assessed. Both treatments resulted in a reduction of the dormancy period and in rapid and synchronised sprouting of the treated tubers when compared to the control as well as in increased sprout number per tuber. In the third approach, the effect of CAT inhibition on potato tuber dormancy and sprouting was evaluated using the transgenic technology. Plants partially repressed in their CAT activity were produced and, once again, CAT inhibition resulted in acceleration of the sprouting kinetics and in increased sprout number of the transgenic tubers compared to those from the wild type. It thus appears that tuber dormancy and sprouting can be controlled in potato by the manipulation of H2O2 metabolism via the inhibition of CAT activity. The possible mechanisms whereby CAT inhibitors or H2O2 overcome dormancy and promote sprouting in the potato tuber are discussed in relation to what is known in other plant models (seeds and fruit tree buds.

  1. The use of glucose oxidase and catalase for the enzymatic reduction of the potential ethanol content in wine.

    Science.gov (United States)

    Röcker, Jessica; Schmitt, Matthias; Pasch, Ludwig; Ebert, Kristin; Grossmann, Manfred

    2016-11-01

    Due to the increase of sugar levels in wine grapes as one of the impacts of climate change, alcohol reduction in wines becomes a major focus of interest. This study combines the use of glucose oxidase and catalase activities with the aim of rapid conversion of glucose into non-fermentable gluconic acid. The H2O2 hydrolysing activity of purified catalase is necessary in order to stabilize glucose oxidase activity. After establishing the adequate enzyme ratio, the procedure was applied in large-scale trials (16L- and 220L-scale) of which one was conducted in a winery under industrial wine making conditions. Both enzyme activity and wine flavour were clearly influenced by the obligatory aeration in the different trials. With the enzyme treatment an alcohol reduction of 2%vol. was achieved after 30h of aeration. However the enzyme treated wines were significantly more acidic and less typical. PMID:27211694

  2. Overexpression of Bcl2 in osteoblasts inhibits osteoblast differentiation and induces osteocyte apoptosis.

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    Takeshi Moriishi

    Full Text Available Bcl2 subfamily proteins, including Bcl2 and Bcl-X(L, inhibit apoptosis. As osteoblast apoptosis is in part responsible for osteoporosis in sex steroid deficiency, glucocorticoid excess, and aging, bone loss might be inhibited by the upregulation of Bcl2; however, the effects of Bcl2 overexpression on osteoblast differentiation and bone development and maintenance have not been fully investigated. To investigate these issues, we established two lines of osteoblast-specific BCL2 transgenic mice. In BCL2 transgenic mice, bone volume was increased at 6 weeks of age but not at 10 weeks of age compared with wild-type mice. The numbers of osteoblasts and osteocytes increased, but osteoid thickness and the bone formation rate were reduced in BCL2 transgenic mice with high expression at 10 weeks of age. The number of BrdU-positive cells was increased but that of TUNEL-positive cells was unaltered at 2 and 6 weeks of age. Osteoblast differentiation was inhibited, as shown by reduced Col1a1 and osteocalcin expression. Osteoblast differentiation of calvarial cells from BCL2 transgenic mice also fell in vitro. Overexpression of BCL2 in primary osteoblasts had no effect on osteoclastogenesis in co-culture with bone marrow cells. Unexpectedly, overexpression of BCL2 in osteoblasts eventually caused osteocyte apoptosis. Osteocytes, which had a reduced number of processes, gradually died with apoptotic structural alterations and the expression of apoptosis-related molecules, and dead osteocytes accumulated in cortical bone. These findings indicate that overexpression of BCL2 in osteoblasts inhibits osteoblast differentiation, reduces osteocyte processes, and causes osteocyte apoptosis.

  3. Transgenic mice overexpressing γ-aminobutyric acid transporter subtype I develop obesity

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Transgenic mice ubiquitously overexpressing murine γaminobutyric acid transporter subtype I were created. Unexpectedly, these mice markedly exhibited heritable obesity,which features significantly increased body weight and fat deposition. Behavioral examination revealed that transgenic mice have slightly reduced spontaneous locomotive capacity and altered feeding pattern. This preliminary finding indicates that the inappropriate level of γ-aminobutyric acid transporters may be directly or indirectly involved in the pathogenic mechanism underlying certain types of obesity.

  4. Transgenic mice overexpressing γ—aminobutyric acid transporter subtype I develop obesity

    Institute of Scientific and Technical Information of China (English)

    MAYINGHUA; ZHENTONGMEI; 等

    2000-01-01

    Transgenic mice ubiquitously overexpressing murine γ-aminobutyric acid transporter subtype I were created.Unexpectedly,these mice markedly exhibited heritable obesity,which features significantly increased body weight and fat deposition.Behavioral examination revealed that transgenic mice have slightly reduced spontaneous locomotive capacity and altered feeding pattern.This preliminary finding indicates that the inappropriate level of γ-aminobutyric acid transporters may be directly or indirectly involved in the pathogenic mechanism underlying certain types of obesity.

  5. recA and catalase in H sub 2 O sub 2 -mediated toxicity in Neisseria gonorrhoeae

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Charniga, L.; Cohen, M.S. (Univ. of North Carolina, Chapel Hill (USA))

    1990-12-01

    Neisseria gonorrhoeae cells defective in the biosynthesis of the recA gene product are no more sensitive to hydrogen peroxide than wild-type cells. Although gonococci possess nearly 100-fold-greater catalase levels than Escherichia coli, they are more susceptible to hydrogen peroxide than this organism. The natural niche of gonococci undoubtedly results in exposure to oxidant stress; however, they do not demonstrate particularly efficient antioxidant defense systems.

  6. Interaction with the Redox Cofactor MYW and Functional Role of a Mobile Arginine in Eukaryotic Catalase-Peroxidase.

    Science.gov (United States)

    Gasselhuber, Bernhard; Graf, Michael M H; Jakopitsch, Christa; Zamocky, Marcel; Nicolussi, Andrea; Furtmüller, Paul G; Oostenbrink, Chris; Carpena, Xavi; Obinger, Christian

    2016-06-28

    Catalase-peroxidases (KatGs) are unique bifunctional heme peroxidases with an additional posttranslationally formed redox-active Met-Tyr-Trp cofactor that is essential for catalase activity. On the basis of studies of bacterial KatGs, controversial mechanisms of hydrogen peroxide oxidation were proposed. The recent discovery of eukaryotic KatGs with differing pH optima of catalase activity now allows us to scrutinize those postulated reaction mechanisms. In our study, secreted KatG from the fungus Magnaporthe grisea (MagKatG2) was used to analyze the role of a remote KatG-typical mobile arginine that was shown to interact with the Met-Tyr-Trp adduct in a pH-dependent manner in bacterial KatGs. Here we present crystal structures of MagKatG2 at pH 3.0, 5.5, and 7.0 and investigate the mobility of Arg461 by molecular dynamics simulation. Data suggest that at pH ≥4.5 Arg461 mostly interacts with the deprotonated adduct Tyr. Elimination of Arg461 by mutation to Ala slightly increases the thermal stability but does not alter the active site architecture or the kinetics of cyanide binding. However, the variant Arg461Ala lost the wild-type-typical optimum of catalase activity at pH 5.25 (kcat = 6450 s(-1)) but exhibits a broad plateau between pH 4.5 and 7.5 (kcat = 270 s(-1) at pH 5.5). Moreover, significant differences in the kinetics of interconversion of redox intermediates of wild-type and mutant protein mixed with either peroxyacetic acid or hydrogen peroxide are observed. These findings together with published data from bacterial KatGs allow us to propose a role of Arg461 in the H2O2 oxidation reaction of KatG. PMID:27293030

  7. Effects of Saponin from Solanum anguivi Lam. Fruit on Heart and Kidney Superoxide Dismutase, Catalase and Malondialdehyde in Rat

    OpenAIRE

    O.O. Elekofehinti; I.G. Adanlawo; Fakoya, A; J.A. Saliu; S.A. Sodehinde

    2012-01-01

    Reactive Oxygen Species (ROS) are generated via normal metabolic processes or as the products of exogenous insults. They are capable of damaging essential biomolecules and accelerating cancer, cardiovascular diseases and neurodegenerative diseases. In this study, the effect saponin from Solanum anguivi (SAS) fruits on Superoxide Dismutase (SOD), catalase (CAT) and Lipid Peroxidation (LPO) in the homogenates of the hearts and kidney was evaluated. Thirty six male Wister rats of average weight1...

  8. Caloric restriction or catalase inactivation extends yeast chronological lifespan by inducing H2O2 and superoxide dismutase activity

    OpenAIRE

    Mesquita, Ana; Weinberger, Martin; Silva, Alexandra; Sampaio-Marques, Belém; Almeida, Bruno; Leão, Cecília; Costa, Vítor; Rodrigues, Fernando; Burhans, William C.; Ludovico, Paula

    2010-01-01

    The free radical theory of aging posits oxidative damage to macromolecules as a primary determinant of lifespan. Recent studies challenge this theory by demonstrating that in some cases, longevity is enhanced by inactivation of oxidative stress defenses or is correlated with increased, rather than decreased reactive oxygen species and oxidative damage. Here we show that, in Saccharomyces cerevisiae, caloric restriction or inactivation of catalases extends chronological lifespan by inducing el...

  9. Caloric restriction or catalase inactivation extends yeast chronological lifespan by inducing H₂O₂ and superoxide dismutase activity

    OpenAIRE

    Mesquita, Ana Maria Macedo; Weinberger, Martin; Silva, Alexandra; Marques, Belém Sampaio; Almeida, Bruno; Leão, Cecília; Costa, Vitor; Rodrigues, Fernando José dos Santos; Burhans, William C.; Ludovico, Paula

    2010-01-01

    The free radical theory of aging posits oxidative damage to macromolecules as a primary determinant of lifespan. Recent studies challenge this theory by demonstrating that in some cases, longevity is enhanced by inactivation of oxidative stress defenses or is correlated with increased, rather than decreased reactive oxygen species and oxidative damage. Here we show that, in Saccharomyces cerevisiae, caloric restriction or inactivation of catalases extends chronological lifespan by inducing el...

  10. Targeting of human catalase to peroxisomes is dependent upon a novel COOH-terminal peroxisomal targeting sequence

    OpenAIRE

    1996-01-01

    We have identified a novel peroxisomal targeting sequence (PTS) at the extreme COOH terminus of human catalase. The last four amino acids of this protein (-KANL) are necessary and sufficient to effect targeting to peroxisomes in both human fibroblasts and Saccharomyces cerevisiae, when appended to the COOH terminus of the reporter protein, chloramphenicol acetyl transferase. However, this PTS differs from the extensive family of COOH-terminal PTS tripeptides collectively termed PTS1 in two ma...

  11. Influence of the lead ions and low dose radiation on the catalase activity in the maize germinant

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2006-02-01

    Full Text Available The experimental results of changes of the catalase activity in the maize germinants under the influence of the lead ions and low doses of radiation separately and simultaneously are presented. The consentration of the lead was 1 · 10 – 4 M and the radiation dozes were 2, 5, 10, and 15 R.

  12. Effects of Soy-Germ Protein on Catalase Activity of Plasma and Erythocyte of Metabolic Syndrome Women

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    Hery Winarsi

    2015-01-01

    Full Text Available Oxidative stress always accompany patients with metabolic syndrome (MS. Several researchers reported that soy-protein is able to decrease oxidative stress level. However, there is no report so far about soy-germ protein in relation to its potential to the decrease oxidative stress level of MS patients. The aim of this study was to explore the potential of soy-germ protein on activity of catalase enzyme in blood’s plasma as well as erythrocytes of MS patients. Double-blind randomized clinical trial was used as an experimental study. Thirty respondents were included in this study with MS, normal level blood sugar, low-HDL cholesterol but high in triglyceride, 40-65 years old, Body Mass Index > 25 kg/m2, live in Purwokerto and agreed to sign the informed consent. They were randomly grouped into 3 different groups, 10 each: Group I, was given special milk that contains soy-germ protein and Zn; Group II, soy-germ protein, while Group III was placebo; for two consecutive months. Data were taken from blood samples in 3 different periods i.e. 0, 1, and 2 months after treatment. Two months after treatment, there was an increase from 5.36 to 20.17 IU/mg (P = 0.028 in activity of catalase enzyme in blood’s plasma respondents who consumed milk containing soy-germ protein with or without Zn. A similar trend of catalase activity, but at a lower level, was also noticed in erythrocyte; which increased from 88.31 to 201.11 IU/mg (P = 0.013. The increase in activity of catalase enzyme in blood’s plasma was 2.2 times higher than that in erythrocytes.

  13. The Catalase –262C/T Promoter Polymorphism and Diabetic Complications in Caucasians with Type 2 Diabetes

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    Kátia Gonçalves dos Santos

    2006-01-01

    Full Text Available Catalase is a central antioxidant enzyme constituting the primary defense against oxidative stress. In this study, we investigated whether the functional –262C/T polymorphism in the promoter of catalase gene is associated with the presence of diabetic retinopathy (DR, diabetic nephropathy (DN and ischemic heart disease (IHD in 520 Caucasian-Brazilians with type 2 diabetes. The –262C/T polymorphism was also examined in 100 Caucasian blood donors. Patients underwent a clinical and laboratory evaluation consisting of a questionnaire, physical examination, assessment of diabetic complications and laboratory tests. Genotype analysis was performed using the polymerase chain reaction followed by digestion with restriction enzyme. The genotype and allele frequencies of the –262C/T polymorphism in patients with type 2 diabetes were very similar to those of blood donors (T allele frequency = 0.20 and 0.18, respectively. Likewise, there were no differences in either genotype or allele frequencies between type 2 diabetic patients with or without DR, DN or IHD. Thus, our results do not support the hypothesis that the –262C/T polymorphism is related to the development of DR, DN or IHD in patients with type 2 diabetes. Further studies are necessary to elucidate the role of catalase gene polymorphisms in the pathogenesis of diabetic complications.

  14. Influence of nutritive substrate and pH on catalase and peroxidase production in saprophytic fungus Rhizopus nigricans

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    Tamara Barbaneagra

    2012-10-01

    Full Text Available Aerobic organisms are vulnerable to action of reactive oxygen species that are very noxious and may beresponsible for damage of all cellular constituents. Most organisms have developed defense mechanisms to protect cells from high levels of free radicals. The purpose of this paper is to determine the antioxidant response in fungus Rhizopus nigricans, materialized trough enzymatic activity of biochemical markers of oxidative stress – catalase and peroxidase.We followed the influence of culture medium pH and nutrient substrate on development of the two enzymes. Enzymaticassays were performed at intervals of 5, 10 and 15 days, using both fungus mycelium and culture liquid. Development of the fungus was completely inhibited at pH 2. Catalase and peroxidase production was mostly endocellular because in theculture liquid in most work variants enzymatic assay was not possible and in the remaining work variants were recordedlow values for catalase and extremely low, near to zero for peroxidase.

  15. A potential oncogenic role of the commonly observed E2F5 overexpression in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yuzhu Jiang; Seon-Hee Yim; Hai-Dong Xu; Seung-Hyun Jung; So Young Yang; Hae-Jin Hu; Chan-Kwon Jung; Yeun-Jun Chung

    2011-01-01

    AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined. RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021). CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells.

  16. Overexpression of protein disulfide isomerase in Aspergillus.

    Science.gov (United States)

    El-Adawi, H; Khanh, N Q; Gassen, H

    2000-10-01

    One of the major problems with the production of biotechnologically valuable proteins has been the purification of the product. For Escherichia coli and Saccharomyces cerevisiae, there are several techniques for the purification of intracellular proteins, but these are time consuming and often result in poor yields. Purification can be considerably facilitated, if the product is secreted from the host cell. In the work presented, we have constructed an expression vector (pSGNH2) for the secretion of protein disulfide isomerase (PDI; EC 5.3.4.1) from Aspergillus niger, in which the retention signal His-Asp-Glu-Leu (H-D-E-L) was modified to Ala-Leu-Glu-Gln (A-L-E-Q) via the polymerase chain reaction (PCR) method. The PDI gene was placed under the control of the A. oryzae alpha-amylase promoter. This expression vector was transformed into A. niger NRRL3, resulting in PDI secretion into the medium. The catalytic activity of overexpressed PDI from A. niger was indistinguishable from that of PDI isolated from bovine liver. With further strain improvement and optimization of culture conditions, it could be possible to raise the PDI production to the bioprocessing scale. PMID:10977899

  17. Vldlr overexpression causes hyperactivity in rats

    Directory of Open Access Journals (Sweden)

    Iwata Keiko

    2012-10-01

    Full Text Available Abstract Background Reelin regulates neuronal positioning in cortical brain structures and neuronal migration via binding to the lipoprotein receptors Vldlr and Lrp8. Reeler mutant mice display severe brain morphological defects and behavioral abnormalities. Several reports have implicated reelin signaling in the etiology of neurodevelopmental and psychiatric disorders, including autism, schizophrenia, bipolar disorder, and depression. Moreover, it has been reported that VLDLR mRNA levels are increased in the post-mortem brain of autistic patients. Methods We generated transgenic (Tg rats overexpressing Vldlr, and examined their histological and behavioral features. Results Spontaneous locomotor activity was significantly increased in Tg rats, without detectable changes in brain histology. Additionally, Tg rats tended to show performance deficits in the radial maze task, suggesting that their spatial working memory was slightly impaired. Thus, Vldlr levels may be involved in determining locomotor activity and memory function. Conclusions Unlike reeler mice, patients with neurodevelopmental or psychiatric disorders do not show striking neuroanatomical aberrations. Therefore, it is notable, from a clinical point of view, that we observed behavioral phenotypes in Vldlr-Tg rats in the absence of neuroanatomical abnormalities.

  18. Frequent Nek1 overexpression in human gliomas.

    Science.gov (United States)

    Zhu, Jun; Cai, Yu; Liu, Pin; Zhao, Weiguo

    2016-08-01

    Never in mitosis A (NIMA)-related kinase 1 (Nek1) regulates cell cycle progression to mitosis. Its expression and potential functions in human gliomas have not been studied. Here, our immunohistochemistry (IHC) assay and Western blot assay results showed that Nek1 expression was significantly upregulated in fresh and paraffin-embedded human glioma tissues. Its level in normal brain tissues was low. Nek1 overexpression in human gliomas was correlated with the proliferation marker (Ki-67), tumor grade, Karnofsky performance scale (KPS) and more importantly, patients' poor survival. Further studies showed that Nek1 expression level was also increased in multiple human glioma cell lines (U251-MG, U87-MG, U118, H4 and U373). Significantly, siRNA-mediated knockdown of Nek1 inhibited glioma cell (U87-MG/U251-MG) growth. Nek1 siRNA also sensitized U87-MG/U251-MG cells to temozolomide (TMZ), causing a profound apoptosis induction and growth inhibition. The current study indicates Nek1 might be a novel and valuable oncotarget of glioma, it is important for glioma cell growth and TMZ-resistance. PMID:27251576

  19. Catalase activity is stimulated by H2O2 in rich culture medium and is required for H2O2 resistance and adaptation in yeast ☆

    OpenAIRE

    Dorival Martins; English, Ann M.

    2014-01-01

    Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1) protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A) does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4). This we attributed to...

  20. Enhanced migration of tissue inhibitor of metalloproteinase overexpressing hepatoma cells is attributed to gelatinases:Relevance to intracellular signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Elke Roeb; Anja-Katrin Bosserhoff; Sabine Hamacher; Bettina Jansen; Judith Dahmen; Sandra Wagner; Siegfried Matern

    2005-01-01

    AIM: To study the effect of gelatinases (especially MMP-9)on migration of tissue inhibitor of metalloproteinase (TIMP-1) overexpressing hepatoma cells.METHODS: Wild type HepG2 cells, cells stably transfected with TIMP-1 and TIMP-1 antagonist (MMP-9-H401A, a catalytically inactive matrix metalloproteinase (MMP) which still binds and neutralizes TIMP-1) were incubated in Boyden chambers either with or without Galardin (a synthetic inhibitor of MMP-1, -2, -3, -8, -9) or a specific inhibitor of gelatinases.RESULTS: Compared to wild type HepG2 cells, the cells overexpressing TIMP-1 showed 115% migration (P<0.05)and the cells overexpressing MMP-9-H401A showed 62% migration (P<0.01). Galardin reduced cell migration dose dependently in all cases. The gelatinase inhibitor reduced migration in TIMP-1 overexpressing cells predominantly.Furthermore, we examined intracellular signal transduction pathways of TIMP-1-dependent HepG2 cells. TIMP-1deactivates cell signaling pathways of MMP-2 and MMP-9involving p38 mitogen-activated protein kinase. Specific blockade of the ERK pathway suppresses gelatinase expression either in the presence or absence of TIMP-1.CONCLUSION: Overexpressing functional TIMP-1-enhanced migration of HepG2-TIMP-1 cells depends on enhanced MMP-activity, especially MMP-9.

  1. AMPKα1 overexpression alleviates the hepatocyte model of nonalcoholic fatty liver disease via inactivating p38MAPK pathway.

    Science.gov (United States)

    Zhang, Hong-Ai; Yang, Xiao-Yan; Xiao, Yan-Feng

    2016-05-27

    Nonalcoholic fatty liver disease (NAFLD) has a wide spectrum of liver damage with a worldwide prevalence of almost 20%. AMP-activated protein kinase α1 (AMPKα1) is an energy sensor that plays a key role in regulating lipid metabolism of the liver. This study explores the role of AMPKα1 overexpression in a steatotic hepatocyte model. The results displayed that the AMPKα1 overexpression suppressed lipid accumulation in the cytoplasm, decreased triglyceride levels, maintained the survival of steatotic hepatocyte model with decreased cell apoptosis and increased survival rate. Besides, AMPKα1 overexpression promoted the expression of lipid catabolism-related genes, reduced the level of anabolism-related genes, alleviated the inflammatory response by reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines. Moreover, AMPKα1 overexpression could inhibit the activation of p38 mitogen-activated protein kinase (p38MAPK). Finally, Anisomycin, a frequently-used activator of p38MAPK, reversed the inhibitory effect of pc-AMPKα1 on the expression of p-p38MAPK, suggesting that AMPKα1 overexpression alleviates inflammatory response through the inactivation of p38MAPK. These results indicated that AMPKα1 may serve as a novel target for treatment of NAFLD. PMID:27109475

  2. Overexpression of Glycolate Oxidase Confers Improved Photosynthesis under High Light and High Temperature in Rice

    Science.gov (United States)

    Cui, Li-Li; Lu, Yu-sheng; Li, Yong; Yang, Chengwei; Peng, Xin-Xiang

    2016-01-01

    While glycolate oxidase (GLO) is well known as a key enzyme for the photorespiratory metabolism in plants, its physiological function and mechanism remains to be further clarified. Our previous studies have shown that suppression of GLO in rice leads to stunted growth and inhibited photosynthesis (Pn) which is positively and linearly correlated with decreased GLO activities. It is, therefore, of interest to further understand whether Pn can be improved when GLO is up-regulated? In this study, four independent overexpression rice lines, with gradient increases in GLO activity, were generated and functionally analyzed. Phenotypic observations showed that the growth could be improved when GLO activities were increased by 60 or 100%, whereas reduced growth was noticed when the activity was further increased by 150 or 210%. As compared with WT plants, all the overexpression plants exhibited significantly improved Pn under conditions of high light and high temperature, but not under normal conditions. In addition, the overexpression plants were more resistant to the MV-induced photooxidative stress. It was further demonstrated that the antioxidant enzymes, and the antioxidant metabolite glutathione was not significantly altered in the overexpression plants. In contrast, H2O2 and salicylic acid (SA) were correspondingly induced upon the GLO overexpression. Taken together, the results suggest that GLO may play an important role for plants to cope with high light and high temperature, and that H2O2 and SA may serve as signaling molecules to trigger stress defense responses but antioxidant reactions appear not to be involved in the defense. PMID:27540387

  3. Impaired baroreflex function in mice overexpressing alpha-synuclein

    Directory of Open Access Journals (Sweden)

    Sheila eFleming

    2013-07-01

    Full Text Available Cardiovascular autonomic dysfunction, such as orthostatic hypotension consequent to baroreflex failure and cardiac sympathetic denervation, is frequently observed in the synucleinopathy Parkinson’s disease (PD. In the present study, the baroreceptor reflex was assessed in mice overexpressing human wildtype alpha-synuclein (Thy1-aSyn, a genetic mouse model of synucleinopathy. The beat-to-beat change in heart rate, computed from R-R interval, in relation to blood pressure was measured in anesthetized and conscious mice equipped with arterial blood pressure telemetry transducers during transient bouts of hypertension and hypotension. Compared to wildtype, tachycardia following nitroprusside-induced hypotension was significantly reduced in Thy1-aSyn mice. Thy1-aSyn mice also showed an abnormal cardiovascular response (i.e., diminished tachycardia to muscarinic blockade with atropine. We conclude that Thy1-aSyn mice have impaired basal and dynamic range of sympathetic and parasympathetic-mediated changes in heart rate and will be a useful model for long-term study of cardiovascular autonomic dysfunction associated with PD.

  4. Overexpression of DRAM enhances p53-dependent apoptosis

    International Nuclear Information System (INIS)

    Tumor suppressor p53-dependent apoptosis is thought to be one of the most important tumor-suppressive mechanisms in human tumorigenesis. Till date, “super p53” mutants exhibiting more potent ability to induce apoptosis than wild-type p53 have been reported. These super p53s may provide a clue for development of novel therapeutic targets. However, the major mechanism underlying the super p53-dependent apoptosis remains unclear. To identify critical gene(s) in this mechanism, we performed a comprehensive and comparative expression analysis in p53-null Saos-2 cells with conditional expression of wild-type p53 and S121F, which was previously reported as a super p53 mutant. We identified damage-regulated autophagy modulator (DRAM) as one of the genes that were more upregulated by S121F than wild-type p53. Although knockdown of DRAM was not sufficient for reducing the ability of S121F to induce apoptosis, DRAM overexpression enhanced the ability in a wild-type p53-dependent manner. Here, we show that DRAM is an important gene for the enhancement of p53-dependent apoptosis. Additional analysis of the mechanism of super p53-dependent apoptosis may lead to the identification of novel drug targets for cancer therapy

  5. Ectopic overexpression of the cell wall invertase gene CIN1 leads to dehydration avoidance in tomato

    DEFF Research Database (Denmark)

    Albacete, Alfonso; Cantero-Navarro, Elena; Grosskinsky, Dominik Kilian;

    2015-01-01

    %), markedly improving water stress adaptation through an efficient physiological strategy of dehydration avoidance. Drought stress strongly reduced cwInv activity and induced its proteinaceous inhibitor in the leaves of the wild-type plants. However, the CIN1-overexpressing plants registered 3- to 6-fold...

  6. Overexpression of Ferredoxin, PETF, Enhances Tolerance to Heat Stress in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Li-Fen Huang

    2013-10-01

    Full Text Available Reactive oxygen species (ROS produced by plants in adverse environments can cause damage to organelles and trigger cell death. Removal of excess ROS can be achieved through the ascorbate scavenger pathway to prevent plant cell death. The amount of this scavenger can be regulated by ferredoxin (FDX. Chloroplastic FDXs are electron transfer proteins that perform in distributing photosynthetic reducing power. In this study, we demonstrate that overexpression of the endogenous photosynthetic FDX gene, PETF, in Chlamydomonas reinhardtii could raise the level of reduced ascorbate and diminish H2O2 levels under normal growth conditions. Furthermore, the overexpressing PETF transgenic Chlamydomonas lines produced low levels of H2O2 and exhibited protective effects that were observed through decreased chlorophyll degradation and increased cell survival under heat-stress conditions. The findings of this study suggest that overexpression of PETF can increase the efficiency of ROS scavenging in chloroplasts to confer heat tolerance. The roles of PETF in the downregulation of the ROS level offer a method for potentially improving the tolerance of crops against heat stress.

  7. Virulence of catalase-deficient aspergillus nidulans in p47(phox)-/- mice. Implications for fungal pathogenicity and host defense in chronic granulomatous disease.

    OpenAIRE

    Chang, Y.C.; Segal, B.H.; Holland, S M; Miller, G.F.; Kwon-Chung, K. J.

    1998-01-01

    Chronic granulomatous disease (CGD) is a rare genetic disorder in which phagocytes fail to produce superoxide because of defects in one of several components of the NADPH oxidase complex. As a result, patients develop recurrent life-threatening bacterial and fungal infections. The organisms to which CGD patients are most susceptible produce catalase, regarded as an important factor for microbial pathogenicity in CGD. To test the role of pathogen-derived catalase in CGD directly, we have gener...

  8. Overexpressing OsPIN2 enhances aluminium internalization by elevating vesicular trafficking in rice root apex

    OpenAIRE

    Wu, Daoming; Shen, Hong; Yokawa, Ken; Baluška, František

    2015-01-01

    Aluminium (Al) sequestration is required for internal detoxification of Al in plant cells. In this study, it was found that the rice OsPIN2 overexpression line (OX1) had significantly reduced Al content in its cell wall and increased Al concentration in cell sap only in rice root tips relative to the wild-type (WT). In comparison with WT, OX1 reduced morin staining of cytosolic Al, enhanced FM 4–64 staining of membrane vesicular trafficking in root tip sections (0–1mm), and showed morin-FM 4–...

  9. [Overexpression of FKS1 to improve yeast autolysis-stress].

    Science.gov (United States)

    Li, Jia; Wang, Jinjing; Li, Qi

    2015-09-01

    With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing. PMID:26955712

  10. Evidence that SOX2 overexpression is oncogenic in the lung.

    Directory of Open Access Journals (Sweden)

    Yun Lu

    Full Text Available BACKGROUND: SOX2 (Sry-box 2 is required to maintain a variety of stem cells, is overexpressed in some solid tumors, and is expressed in epithelial cells of the lung. METHODOLOGY/PRINCIPAL FINDINGS: We show that SOX2 is overexpressed in human squamous cell lung tumors and some adenocarcinomas. We have generated mouse models in which Sox2 is upregulated in epithelial cells of the lung during development and in the adult. In both cases, overexpression leads to extensive hyperplasia. In the terminal bronchioles, a trachea-like pseudostratified epithelium develops with p63-positive cells underlying columnar cells. Over 12-34 weeks, about half of the mice expressing the highest levels of Sox2 develop carcinoma. These tumors resemble adenocarcinoma but express the squamous marker, Trp63 (p63. CONCLUSIONS: These findings demonstrate that Sox2 overexpression both induces a proximal phenotype in the distal airways/alveoli and leads to cancer.

  11. The Effect of MicroRNA-124 Overexpression on Anti-Tumor Drug Sensitivity.

    Directory of Open Access Journals (Sweden)

    Shiau-Mei Chen

    Full Text Available MicroRNAs play critical roles in regulating various physiological processes, including growth and development. Previous studies have shown that microRNA-124 (miR-124 participates not only in regulation of early neurogenesis but also in suppression of tumorigenesis. In the present study, we found that overexpression of miR-124 was associated with reduced DNA repair capacity in cultured cancer cells and increased sensitivity of cells to DNA-damaging anti-tumor drugs, specifically those that cause the formation of DNA strand-breaks (SBs. We then examined which DNA repair-related genes, particularly the genes of SB repair, were regulated by miR-124. Two SB repair-related genes, encoding ATM interactor (ATMIN and poly (ADP-ribose polymerase 1 (PARP1, were strongly affected by miR-124 overexpression, by binding of miR-124 to the 3¢-untranslated region of their mRNAs. As a result, the capacity of cells to repair DNA SBs, such as those resulting from homologous recombination, was significantly reduced upon miR-124 overexpression. A particularly important therapeutic implication of this finding is that overexpression of miR-124 enhanced cell sensitivity to multiple DNA-damaging agents via ATMIN- and PARP1-mediated mechanisms. The translational relevance of this role of miR-124 in anti-tumor drug sensitivity is suggested by the finding that increased miR-124 expression correlates with better breast cancer prognosis, specifically in patients receiving chemotherapy. These findings suggest that miR-124 could potentially be used as a therapeutic agent to improve the efficacy of chemotherapy with DNA-damaging agents.

  12. Overexpression of inosine 5'-monophosphate dehydrogenase type II mediates chemoresistance to human osteosarcoma cells.

    Directory of Open Access Journals (Sweden)

    Jörg Fellenberg

    Full Text Available BACKGROUND: Chemoresistance is the principal reason for poor survival and disease recurrence in osteosarcoma patients. Inosine 5'-monophosphate dehydrogenase type II (IMPDH2 encodes the rate-limiting enzyme in the de novo guanine nucleotide biosynthesis and has been linked to cell growth, differentiation, and malignant transformation. In a previous study we identified IMPDH2 as an independent prognostic factor and observed frequent IMPDH2 overexpression in osteosarcoma patients with poor response to chemotherapy. The aim of this study was to provide evidence for direct involvement of IMPDH2 in the development of chemoresistance. METHODOLOGY/PRINCIPAL FINDINGS: Stable cell lines overexpressing IMPDH2 and IMPDH2 knock-down cells were generated using the osteosarcoma cell line Saos-2 as parental cell line. Chemosensitivity, proliferation, and the expression of apoptosis-related proteins were analyzed by flow cytometry, WST-1-assay, and western blot analysis. Overexpression of IMPDH2 in Saos-2 cells induced strong chemoresistance against cisplatin and methotrexate. The observed chemoresistance was mediated at least in part by increased expression of the anti-apoptotic proteins Bcl-2, Mcl-1, and XIAP, reduced activation of caspase-9, and, consequently, reduced cleavage of the caspase substrate PARP. Pharmacological inhibition of IMPDH induced a moderate reduction of cell viability and a strong decrease of cell proliferation, but no increase in chemosensitivity. However, chemoresistant IMPDH2-overexpressing cells could be resensitized by RNA interference-mediated downregulation of IMPDH2. CONCLUSIONS: IMPDH2 is directly involved in the development of chemoresistance in osteosarcoma cells, suggesting that targeting of IMPDH2 by RNAi or more effective pharmacological inhibitors in combination with chemotherapy might be a promising means of overcoming chemoresistance in osteosarcomas with high IMPDH2 expression.

  13. Odontoblast-targeted Bcl-2 Overexpression Impairs Dentin Formation

    OpenAIRE

    Zhang, Wenjian; Ju, Jun; Gronowicz, Gloria

    2010-01-01

    Apoptosis has been described extensively in tooth development, which is under tight control of multiple apoptosis regulators, including anti-apoptotic protein Bcl-2. However, it is totally unclear how Bcl-2 is related to odontogenesis, especially dentinogenesis. Using a transgenic mouse Col2.3Bcl-2 in which human Bcl-2 was overexpressed in odontoblasts, the effect of Bcl-2 on dentinogenesis was investigated. Overexpression of Bcl-2 was detected by immunohistochemistry and Western blot. Odonto...

  14. Transgenic cyclooxygenase-2 overexpression sensitizes mouse skin for carcinogenesis

    OpenAIRE

    Müller-Decker, Karin; Neufang, Gitta; Berger, Irina; Neumann, Melanie; Marks, Friedrich; Fürstenberger, Gerhard

    2002-01-01

    Genetic and pharmacological evidence suggests that overexpression of cyclooxygenase-2 (COX-2) is critical for epithelial carcinogenesis and provides a major target for cancer chemoprevention by nonsteroidal antiinflammatory drugs. Transgenic mouse lines with keratin 5 promoter-driven COX-2 overexpression in basal epidermal cells exhibit a preneoplastic skin phenotype. As shown here, this phenotype depends on the level of COX-2 expression and COX-2-mediated prostaglandin accumulation. The tran...

  15. Sesamin Modulates Tyrosine Hydroxylase, Superoxide Dismutase, Catalase, Inducible No Synthase and Interleukin-6 Expression in Dopaminergic Cells Under Mpp+-Induced Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Vicky Lahaie-Collins

    2008-01-01

    Full Text Available Oxidative stress is regarded as a mediator of nerve cell death in several neurodegenerative disorders, such as Parkinson's disease. Sesamin, a lignan mainly found in sesame oil, is currently under study for its anti-oxidative and possible neuroprotective properties. We used 1-methyl-4-phenyl-pyridine (MPP+ ion, the active metabolite of the potent parkinsonism-causing toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, to produce oxidative stress and neurodegeneration in neuronal PC12 cells, which express dopamine, as well as neurofilaments. Our results show that picomolar doses of sesamin protected neuronal PC12 cells from MPP+-induced cellular death, as revealed by colorimetric measurements and production of reactive oxygen species. We also demonstrated that sesamin acted by rescuing tyrosine hydroxylase levels from MPP+-induced depletion. Sesamin, however, did not modulate dopamine transporter levels, and estrogen receptor-alpha and -beta protein expression. By examining several parameters of cell distress, we found that sesamin also elicited a strong increase in superoxide dismutase activity as well as protein expression and decreased catalase activity and the MPP+ stimulated inducible nitric oxide synthase protein expression, in neuronal PC12 cells. Finally, sesamin possessed significant anti-inflammatory properties, as disclosed by its potential to reduce MPP+-induced interleukin-6 mRNA levels in microglia. From these studies, we determined the importance of the lignan sesamin as a neuroprotective molecule and its possible role in complementary and/or preventive therapies of neurodegenerative diseases.

  16. Assessment of tick antioxidant responses to exogenous oxidative stressors and insight into the role of catalase in the reproductive fitness of the Gulf Coast tick, Amblyomma maculatum.

    Science.gov (United States)

    Kumar, D; Budachetri, K; Meyers, V C; Karim, S

    2016-06-01

    As obligate blood-sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H2 O2 ) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H2 O2 or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2-16-fold increases in target antioxidant gene transcripts, signifying the ability of Am. maculatum to regulate its antioxidant machinery when exposed to increased ROS levels. Next, RNA interference was used to determine the functional role of CAT in haematophagy, redox homeostasis and reproductive fitness. CAT gene silencing was confirmed by transcript depletion within tick tissues; however, CAT knockdown alone did not interfere with tick haematophagy or phenotype, as confirmed by the resulting differential expression of antioxidant genes, thereby indicating an alternative mechanism for ROS control. Interestingly, double stranded RNA of CAT gene (dsCAT) and the CAT inhibitor, 3-aminotriazole, together reduced tick reproductive fitness via a marked reduction in egg mass and larval eclosion rates, highlighting a role for CAT in tick redox-homeostasis, making it a potential target for tick control. PMID:26919203

  17. Sperm characteristics and heterologous in vitro fertilisation capacity of Iberian ibex (Capra pyrenaica) epididymal sperm, frozen in the presence of the enzymatic antioxidant catalase.

    Science.gov (United States)

    López-Saucedo, J; Paramio, M T; Fierro, R; Izquierdo, D; Catalá, M G; Coloma, M A; Toledano-Díaz, A; López-Sebastián, A; Santiago-Moreno, J

    2014-06-01

    The aim of this work was to evaluate the protective effect of catalase (CAT) on frozen/thawed ibex epididymal sperm recovered post mortem, and to detect any harmful effect this might have on sperm fertilisation capacity. Epididymal spermatozoa were diluted using a Tris-citric acid-glucose medium (TCG) composed of 3.8% Tris (w/v), 2.2% citric acid (w/v), 0.6% glucose (w/v), 5% glycerol (v/v), and 6% egg yolk (v/v). Sperm masses from the right epididymis were diluted with TCG medium, while those from the left were diluted with TCG medium supplemented with 200IU/mL CAT. Heterologous in vitro fertilisation (IVF) was used to assess the fertilisation capacity of this sperm. The addition of CAT to the extender did not improve frozen/thawed sperm variables. Moreover, a reduced fertilisation capacity was detected: sperm diluted with TCG provided 25.5% 2PN zygotes, while just 13.2% was recorded for that diluted with TCG-CAT (PTCG sperm than with the TCG-CAT sperm (16.7% vs. 7.6%). The use of 200IU/mL CAT as an additive cannot, therefore, be recommended for the preservation of ibex epididymal sperm. Other antioxidants should, however, be tested in both this and related wild mountain ungulates. PMID:24699464

  18. Nickel and cobalt resistance engineered in Escherichia coli by overexpression of serine acetyltransferase from the nickel hyperaccumulator plant Thlaspi goesingense.

    Science.gov (United States)

    Freeman, John L; Persans, Michael W; Nieman, Ken; Salt, David E

    2005-12-01

    The overexpression of serine acetyltransferase from the Ni-hyperaccumulating plant Thlaspi goesingense causes enhanced nickel and cobalt resistance in Escherichia coli. Furthermore, overexpression of T. goesingense serine acetyltransferase results in enhanced sensitivity to cadmium and has no significant effect on resistance to zinc. Enhanced nickel resistance is directly related to the constitutive overactivation of sulfur assimilation and glutathione biosynthesis, driven by the overproduction of O-acetyl-L-serine, the product of serine acetyltransferase and a positive regulator of the cysteine regulon. Nickel in the serine acetyltransferase-overexpressing strains is not detoxified by coordination or precipitation with sulfur, suggesting that glutathione is involved in reducing the oxidative damage imposed by nickel. PMID:16332856

  19. Glyoxalase 1 overexpression does not affect atherosclerotic lesion size and severity in ApoE-/- mice with or without diabetes

    DEFF Research Database (Denmark)

    Hanssen, Nordin M J; Brouwers, Olaf; Gijbels, Marion J;

    2014-01-01

    E(-/-) huGLO1(+/-) (n = 20) mice. To induce diabetes, we injected a subset with streptozotocin (STZ) to generate diabetic ApoE(-/-) (n = 8) and ApoE(-/-) huGLO1(+/-) (n = 13) mice. All mice were fed chow and sacrificed at 25 weeks of age. The GLO1 activity was three-fold increased in huGLO1(+/-) aorta, but......(+/-) overexpression. Although diabetic mice showed decreased GLO1 expression (P < 0.05) and increased lesion size (P < 0.05) in comparison with non-diabetic mice, GLO1 overexpression also did not affect the aortic root lesion size or inflammation in diabetic mice. CONCLUSION: In ApoE(-/-) mice with or without...... diabetes, GLO1 overexpression did not lead to decreased atherosclerotic lesion size or systemic inflammation. Increasing GLO1 levels does not seem to be an effective strategy to reduce glycation in atherosclerotic lesions, likely due to increased AGE formation through GLO1-independent mechanisms....

  20. Characterization of OxyR as a negative transcriptional regulator that represses catalase production in Corynebacterium diphtheriae.

    Science.gov (United States)

    Kim, Ju-Sim; Holmes, Randall K

    2012-01-01

    Corynebacterium diphtheriae and Corynebacterium glutamicum each have one gene (cat) encoding catalase. In-frame Δcat mutants of C. diphtheriae and C. glutamicum were hyper-sensitive to growth inhibition and killing by H(2)O(2). In C. diphtheriae C7(β), both catalase activity and cat transcription decreased ~2-fold during transition from exponential growth to early stationary phase. Prototypic OxyR in Escherichia coli senses oxidative stress and it activates katG transcription and catalase production in response to H(2)O(2). In contrast, exposure of C. diphtheriae C7(β) to H(2)O(2) did not stimulate transcription of cat. OxyR from C. diphtheriae and C. glutamicum have 52% similarity with E. coli OxyR and contain homologs of the two cysteine residues involved in H(2)O(2) sensing by E. coli OxyR. In-frame ΔoxyR deletion mutants of C. diphtheriae C7(β), C. diphtheriae NCTC13129, and C. glutamicum were much more resistant than their parental wild type strains to growth inhibition by H(2)O(2). In the C. diphtheriae C7(β) ΔoxyR mutant, cat transcripts were about 8-fold more abundant and catalase activity was about 20-fold greater than in the C7(β) wild type strain. The oxyR gene from C. diphtheriae or C. glutamicum, but not from E. coli, complemented the defect in ΔoxyR mutants of C. diphtheriae and C. glutamicum and decreased their H(2)O(2) resistance to the level of their parental strains. Gel-mobility shift, DNaseI footprint, and primer extension assays showed that purified OxyR from C. diphtheriae C7(β) bound, in the presence or absence of DTT, to a sequence in the cat promoter region that extends from nucleotide position -55 to -10 with respect to the +1 nucleotide in the cat ORF. These results demonstrate that OxyR from C. diphtheriae or C. glutamicum functions as a transcriptional repressor of the cat gene by a mechanism that is independent of oxidative stress induced by H(2)O(2). PMID:22438866

  1. Characterization of OxyR as a negative transcriptional regulator that represses catalase production in Corynebacterium diphtheriae.

    Directory of Open Access Journals (Sweden)

    Ju-Sim Kim

    Full Text Available Corynebacterium diphtheriae and Corynebacterium glutamicum each have one gene (cat encoding catalase. In-frame Δcat mutants of C. diphtheriae and C. glutamicum were hyper-sensitive to growth inhibition and killing by H(2O(2. In C. diphtheriae C7(β, both catalase activity and cat transcription decreased ~2-fold during transition from exponential growth to early stationary phase. Prototypic OxyR in Escherichia coli senses oxidative stress and it activates katG transcription and catalase production in response to H(2O(2. In contrast, exposure of C. diphtheriae C7(β to H(2O(2 did not stimulate transcription of cat. OxyR from C. diphtheriae and C. glutamicum have 52% similarity with E. coli OxyR and contain homologs of the two cysteine residues involved in H(2O(2 sensing by E. coli OxyR. In-frame ΔoxyR deletion mutants of C. diphtheriae C7(β, C. diphtheriae NCTC13129, and C. glutamicum were much more resistant than their parental wild type strains to growth inhibition by H(2O(2. In the C. diphtheriae C7(β ΔoxyR mutant, cat transcripts were about 8-fold more abundant and catalase activity was about 20-fold greater than in the C7(β wild type strain. The oxyR gene from C. diphtheriae or C. glutamicum, but not from E. coli, complemented the defect in ΔoxyR mutants of C. diphtheriae and C. glutamicum and decreased their H(2O(2 resistance to the level of their parental strains. Gel-mobility shift, DNaseI footprint, and primer extension assays showed that purified OxyR from C. diphtheriae C7(β bound, in the presence or absence of DTT, to a sequence in the cat promoter region that extends from nucleotide position -55 to -10 with respect to the +1 nucleotide in the cat ORF. These results demonstrate that OxyR from C. diphtheriae or C. glutamicum functions as a transcriptional repressor of the cat gene by a mechanism that is independent of oxidative stress induced by H(2O(2.

  2. Immobilization of Genetically-Modified d-Amino Acid Oxidase and Catalase on Carbon Nanotubes to Improve the Catalytic Efficiency

    OpenAIRE

    Rong Li; Jian Sun; Yaqi Fu; Kun Du; Mengsha Cai; Peijun Ji; Wei Feng

    2016-01-01

    d-amino acid oxidase (DAAO) and catalase (CAT) have been genetically modified by fusing them to an elastin-like polypeptide (ELP). ELP-DAAO and ELP-CAT have been separately immobilized on multi-walled carbon nanotubes (MWNTs). It has been found that the secondary structures of the enzymes have been preserved. ELP-DAAO catalyzed the oxidative deamination of d-alanine, and H2O2 was evolved continuously. When the MWNT-supported enzymes were used together, the generated hydrogen peroxide of ELP-D...

  3. Oxidative stress, hemoglobin content, superoxide dismutase and catalase activity influenced by sulphur baths and mud packs in patients with osteoarthritis

    Directory of Open Access Journals (Sweden)

    Jokić Aleksandar

    2010-01-01

    Full Text Available Background/Aim. It is weel-known that sulphur baths and mud paks demonstrate beneficial effects on patients suffering from degenerative knee and hip osteoarthritis (OA through the increased activity of protective antioxidant enzymes. The aim of this study was to assess lipid peroxidation level, i.e. malondialdehyde concetration, in individuals with knee and/or hip osteoarthritis (OA, as well as to determine the influence of sulphur baths and mud packs application on the activity of superoxide dismutase (SOD and catalase (CAT in order to minimize or eliminate excessive free radical species production (oxidative stress. Methods. Thirty one patiens with knee and/or hip OA of both sexes were included in the study. All OA patients received mud pack and sulphur bath for 20 minutes a day, for 6 consecutive days a week, over 3 weeks. Blood lipid peroxidation, ie malondialdehyde concentration, superoxide dismutase and catalase activity were measured spectrophotometrically, before, on day 5 during the treatment and at the end of spa cure. Healthy volunteers (n = 31 were the controls. Results. The sulphur baths and mud packs treatment of OA patients caused a significant decrease in plasma malondialdehyde concentration compared to the controls ( p < 0.001. The mean SOD activity before the terapy was 1 836.24 U/gHb, on day 5 it rose to 1 942.15 U/gHb and after the spa cure dropped to 1 745.98 U/gHb. Catalase activity before the therapy was 20.56 kU/gHb and at the end of the terapy decreased to 16.16 kU/gHb. The difference in catalase activity before and after the therapy was significant (p < 0.001, and also significant as compared to control (p < 0.001. At the end of the treatment significant increase of hemoglobin level and significant decrease of pain intensity were noticed. Conclusion. A combined 3-week treatment by sulphur bath and mud packs led to a significant decrease of lipid peroxidation in plasma, as well as pain intensity in the patients with OA

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

    OpenAIRE

    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 initi...

  5. Breast tumors in PyMT transgenic mice expressing mitochondrial catalase have decreased labeling for macrophages and endothelial cells

    Directory of Open Access Journals (Sweden)

    Sy Fatemie

    2012-05-01

    Full Text Available We show by immunohistochemical labeling that prominent cell types in the tumor microenvironment of PyMT transgenic mice are tumor-associated macrophages (TAMs and endothelial cells, and that both populations are decreased in the presence of mitochondrial targeted catalase (mCAT. This observation suggests that mitochondrial ROS can drive tumor invasiveness in conjunction with the presence of TAMs and increased angiogenesis. Since primary PyMT tumor cells expressing mCAT undergo increased apoptosis, mitochondrial antioxidants might be attractive anti-tumor agents.

  6. Oxidative DNA damage levels and catalase activity in the clam Ruditapes decussatus as pollution biomarkers of Tunisian marine environment.

    Science.gov (United States)

    Jebali, Jamel; Banni, Mohamed; de Almeida, Eduardo Alves; Boussetta, Hamadi

    2007-01-01

    Levels of the oxidative DNA damage 7, 8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG) and catalase (CAT) activity were measured in the digestive gland and gills of clams Ruditapes decussatus, related to the presence of pollutants along Tunisian marine environment. Increased levels of CAT were observed in tissues of clams from all the sites studied, compared to control values, and elevated 8-oxodG levels were observed at specific sites. Results obtained in this work indicate that the measurement of 8-oxodG levels and CAT activity in tissues of R. decussatus is promising in pollution monitoring studies of the Tunisian marine environment. PMID:16897518

  7. Prolonged ethanol administration depletes mitochondrial DNA in MnSOD-overexpressing transgenic mice, but not in their wild type littermates

    International Nuclear Information System (INIS)

    Alcohol consumption increases reactive oxygen species formation and lipid peroxidation, whose products can damage mitochondrial DNA (mtDNA) and alter mitochondrial function. A possible role of manganese superoxide dismutase (MnSOD) on these effects has not been investigated. To test whether MnSOD overexpression modulates alcohol-induced mitochondrial alterations, we added ethanol to the drinking water of transgenic MnSOD-overexpressing (TgMnSOD) mice and their wild type (WT) littermates for 7 weeks. In TgMnSOD mice, alcohol administration further increased the activity of MnSOD, but decreased cytosolic glutathione as well as cytosolic glutathione peroxidase activity and peroxisomal catalase activity. Whereas ethanol increased cytochrome P-450 2E1 and mitochondrial ROS generation in both WT and TgMnSOD mice, hepatic iron, lipid peroxidation products and respiratory complex I protein carbonyls were only increased in ethanol-treated TgMnSOD mice but not in WT mice. In ethanol-fed TgMnSOD mice, but not ethanol-fed WT mice, mtDNA was depleted, and mtDNA lesions blocked the progress of polymerases. The iron chelator, DFO prevented hepatic iron accumulation, lipid peroxidation, protein carbonyl formation and mtDNA depletion in alcohol-treated TgMnSOD mice. Alcohol markedly decreased the activities of complexes I, IV and V of the respiratory chain in TgMnSOD, with absent or lesser effects in WT mice. There was no inflammation, apoptosis or necrosis, and steatosis was similar in ethanol-treated WT and TgMnSOD mice. In conclusion, prolonged alcohol administration selectively triggers iron accumulation, lipid peroxidation, respiratory complex I protein carbonylation, mtDNA lesions blocking the progress of polymerases, mtDNA depletion and respiratory complex dysfunction in TgMnSOD mice but not in WT mice

  8. Small heterodimer partner overexpression partially protects against liver tumor development in farnesoid X receptor knockout mice

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guodong [Department of Surgical Oncology, Cancer Treatment Center, The Fourth Affiliated Hospital of Harbin Medical University, Harbin (China); Kong, Bo [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Zhu, Yan [Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing (China); Zhan, Le [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Williams, Jessica A. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Tawfik, Ossama [Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Kassel, Karen M. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Luyendyk, James P. [Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI (United States); Wang, Li [Department of Medicine, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT (United States); Guo, Grace L., E-mail: guo@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ (United States)

    2013-10-15

    Farnesoid X receptor (FXR, Nr1h4) and small heterodimer partner (SHP, Nr0b2) are nuclear receptors that are critical to liver homeostasis. Induction of SHP serves as a major mechanism of FXR in suppressing gene expression. Both FXR{sup −/−} and SHP{sup −/−} mice develop spontaneous hepatocellular carcinoma (HCC). SHP is one of the most strongly induced genes by FXR in the liver and is a tumor suppressor, therefore, we hypothesized that deficiency of SHP contributes to HCC development in the livers of FXR{sup −/−} mice and therefore, increased SHP expression in FXR{sup −/−} mice reduces liver tumorigenesis. To test this hypothesis, we generated FXR{sup −/−} mice with overexpression of SHP in hepatocytes (FXR{sup −/−}/SHP{sup Tg}) and determined the contribution of SHP in HCC development in FXR{sup −/−} mice. Hepatocyte-specific SHP overexpression did not affect liver tumor incidence or size in FXR{sup −/−} mice. However, SHP overexpression led to a lower grade of dysplasia, reduced indicator cell proliferation and increased apoptosis. All tumor-bearing mice had increased serum bile acid levels and IL-6 levels, which was associated with activation of hepatic STAT3. In conclusion, SHP partially protects FXR{sup −/−} mice from HCC formation by reducing tumor malignancy. However, disrupted bile acid homeostasis by FXR deficiency leads to inflammation and injury, which ultimately results in uncontrolled cell proliferation and tumorigenesis in the liver. - Highlights: • SHP does not prevent HCC incidence nor size in FXR KO mice but reduces malignancy. • Increased SHP promotes apoptosis. • Bile acids and inflammation maybe critical for HCC formation with FXR deficiency.

  9. Small heterodimer partner overexpression partially protects against liver tumor development in farnesoid X receptor knockout mice

    International Nuclear Information System (INIS)

    Farnesoid X receptor (FXR, Nr1h4) and small heterodimer partner (SHP, Nr0b2) are nuclear receptors that are critical to liver homeostasis. Induction of SHP serves as a major mechanism of FXR in suppressing gene expression. Both FXR−/− and SHP−/− mice develop spontaneous hepatocellular carcinoma (HCC). SHP is one of the most strongly induced genes by FXR in the liver and is a tumor suppressor, therefore, we hypothesized that deficiency of SHP contributes to HCC development in the livers of FXR−/− mice and therefore, increased SHP expression in FXR−/− mice reduces liver tumorigenesis. To test this hypothesis, we generated FXR−/− mice with overexpression of SHP in hepatocytes (FXR−/−/SHPTg) and determined the contribution of SHP in HCC development in FXR−/− mice. Hepatocyte-specific SHP overexpression did not affect liver tumor incidence or size in FXR−/− mice. However, SHP overexpression led to a lower grade of dysplasia, reduced indicator cell proliferation and increased apoptosis. All tumor-bearing mice had increased serum bile acid levels and IL-6 levels, which was associated with activation of hepatic STAT3. In conclusion, SHP partially protects FXR−/− mice from HCC formation by reducing tumor malignancy. However, disrupted bile acid homeostasis by FXR deficiency leads to inflammation and injury, which ultimately results in uncontrolled cell proliferation and tumorigenesis in the liver. - Highlights: • SHP does not prevent HCC incidence nor size in FXR KO mice but reduces malignancy. • Increased SHP promotes apoptosis. • Bile acids and inflammation maybe critical for HCC formation with FXR deficiency

  10. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  11. Catalase activity is stimulated by H2O2 in rich culture medium and is required for H2O2 resistance and adaptation in yeast

    Directory of Open Access Journals (Sweden)

    Dorival Martins

    2014-01-01

    Full Text Available Catalases are efficient scavengers of H2O2 and protect cells against H2O2 stress. Examination of the H2O2 stimulon in Saccharomyces cerevisiae revealed that the cytosolic catalase T (Ctt1 protein level increases 15-fold on H2O2 challenge in synthetic complete media although previous work revealed that deletion of the CCT1 or CTA1 genes (encoding peroxisomal/mitochondrial catalase A does not increase the H2O2 sensitivity of yeast challenged in phosphate buffer (pH 7.4. This we attributed to our observation that catalase activity is depressed when yeast are challenged with H2O2 in nutrient-poor media. Hence, we performed a systematic comparison of catalase activity and cell viability of wild-type yeast and of the single catalase knockouts, ctt1∆ and cta1∆, following H2O2 challenge in nutrient-rich medium (YPD and in phosphate buffer (pH 7.4. Ctt1 but not Cta1 activity is strongly induced by H2O2 when cells are challenged in YPD but suppressed when cells are challenged in buffer. Consistent with the activity results, exponentially growing ctt1∆ cells in YPD are more sensitive to H2O2 than wild-type or cta1∆ cells, whereas in buffer all three strains exhibit comparable H2O2 hypersensitivity. Furthermore, catalase activity is increased during adaptation to sublethal H2O2 concentrations in YPD but not in buffer. We conclude that induction of cytosolic Ctt1 activity is vital in protecting yeast against exogenous H2O2 but this activity is inhibited by H2O2 when cells are challenged in nutrient-free media.

  12. Layer by layer assembly of catalase and amine-terminated ionic liquid onto titanium nitride nanoparticles modified glassy carbon electrode: Study of direct voltammetry and bioelectrocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Saadati, Shagayegh [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Salimi, Abdollah, E-mail: absalimi@uok.ac.ir [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hallaj, Rahman; Rostami, Amin [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

    2012-11-13

    Highlights: Black-Right-Pointing-Pointer Catalase and amine-terminated ionic liquid were immobilized to GC/TiNnp with LBL assembly method. Black-Right-Pointing-Pointer First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation. Black-Right-Pointing-Pointer With alternative assemble of IL and catalase with positive and negative charged, multilayer was formed. Black-Right-Pointing-Pointer Immobilized catalase shows excellent electrocatalytic activity toward H{sub 2}O{sub 2} reduction. Black-Right-Pointing-Pointer Biosensor response is directly correlated to the number of bilayers. - Abstract: A novel, simple and facile layer by layer (LBL) approach is used for modification of glassy carbon (GC) electrode with multilayer of catalase and nanocomposite containing 1-(3-Aminopropyl)-3-methylimidazolium bromide (amine terminated ionic liquid (NH{sub 2}-IL)) and titanium nitride nanoparticles (TiNnp). First a thin layer of NH{sub 2}-IL is covalently attached to GC/TiNnp electrode using electro-oxidation method. Then, with alternative self assemble positively charged NH{sub 2}-IL and negatively charged catalase a sensitive H{sub 2}O{sub 2} biosensor is constructed, whose response is directly correlated to the number of bilayers. The surface coverage of active catalase per bilayer, heterogeneous electron transfer rate constant (k{sub s}) and Michaelis-Menten constant (K{sub M}) of immobilized catalase were 3.32 Multiplication-Sign 10{sup -12} mol cm{sup -2}, 5.28 s{sup -1} and 1.1 mM, respectively. The biosensor shows good stability, high reproducibility, long life-time, and fast amperometric response with the high sensitivity of 380 {mu}A mM{sup -1} cm{sup -2} and low detection limit of 100 nM at concentration range up to 2.1 mM.

  13. Overexpression of SOCS3 exhibits preclinical antitumor activity against malignant pleural mesothelioma.

    Science.gov (United States)

    Iwahori, Kota; Serada, Satoshi; Fujimoto, Minoru; Nomura, Shintaro; Osaki, Tadashi; Lee, Chun Man; Mizuguchi, Hiroyuki; Takahashi, Tsuyoshi; Ripley, Barry; Okumura, Meinoshin; Kawase, Ichiro; Kishimoto, Tadamitsu; Naka, Tetsuji

    2011-08-15

    Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis for which an effective therapy remains to be established. Our study investigated the therapeutic potential of the suppressor of cytokine signaling 3 (SOCS3), an endogenous inhibitor of intracellular signaling pathways, for treatment of MPM. We infected MPM cells (H226, EHMES-1, MESO-1 and MESO-4) with an adenovirus-expressing SOCS3 (AdSOCS3) to examine the effect of SOCS3 overexpression on MPM cells. SOCS3 overexpression reduced MPM proliferation and induced apoptosis and partial G0/G1 arrest. SOCS3 also inhibited the proliferation of MPM cells via multiple signaling pathways including Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), extracellular signal-regulated kinase (ERK), focal adhesion kinase (FAK) and p53 pathways. Notably, AdSOCS3 treatment inhibited tumor growth in an MPM pleural xenograft model. These findings demonstrate that overexpression of SOCS3 has a potent antitumor effect against MPM both in vitro and in vivo and indicate the potential for clinical use of SOCS3 for MPM treatment. PMID:20949562

  14. Impaired reproduction in transgenic mice overexpressing γ-aminobutyric acid transporter I (GAT1)

    Institute of Scientific and Technical Information of China (English)

    Jia Hua HU; Jin Fu ZHANG; Ying Hua MA; Jie JIANG; Na YANG; Xin Bo LI; Zhi Guang YU CHI; Jian FEI; Li He GUO

    2004-01-01

    It is well documented that γ-aminobutyric acid (GABA) system existed in reproductive organs. Recent researches showed that GABAA and GABAB receptors were present in testis and sperm,and might mediate the acrosome reaction induced by GABA and progesterone. GABA transporter I (GAT1) also existed in testis and sperm,but its physiological function was unknown. In the present study,we used GAT1 overexpressing mice to explore GAT1 function in male reproductive system. We found that the expression level of GAT1 continuously increased in wild-type mouse testis from 1 month to 2 months after birth. GAT1 overexpression in mouse affected testis development,which embodied reduced testis mass and slowed spermatogenesis in transgenic mice. Moreover,transgenic mice showed increase of the percentage of broken sperm. The further study revealed that the reproductive capacity was impaired in GAT1 overexpressing mice. In addition,testosterone level was significantly low in transgenic mice compared with that in wild-type mice. Our findings provided the first evidence that abnormal expression of GAT1 could result in dysgenesis,and indicated that GAT1 might be therapeutically targeted for contraception or dysgenesis treatment.

  15. Behind melanocortin antagonist overexpression in the zebrafish brain: A behavioral and transcriptomic approach.

    Science.gov (United States)

    Guillot, Raúl; Cortés, Raúl; Navarro, Sandra; Mischitelli, Morena; García-Herranz, Víctor; Sánchez, Elisa; Cal, Laura; Navarro, Juan Carlos; Míguez, Jesús M; Afanasyev, Sergey; Krasnov, Aleksei; Cone, Roger D; Rotllant, Josep; Cerdá-Reverter, Jose Miguel

    2016-06-01

    Melanocortin signaling is regulated by the binding of naturally occurring antagonists, agouti-signaling protein (ASIP) and agouti-related protein (AGRP) that compete with melanocortin peptides by binding to melanocortin receptors to regulate energy balance and growth. Using a transgenic model overexpressing ASIP, we studied the involvement of melanocortin system in the feeding behaviour, growth and stress response of zebrafish. Our data demonstrate that ASIP overexpression results in enhanced growth but not obesity. The differential growth is explained by increased food intake and feeding efficiency mediated by a differential sensitivity of the satiety system that seems to involve the cocaine- and amphetamine- related transcript (CART). Stress response was similar in both genotypes. Brain transcriptome of transgenic (ASIP) vs wild type (WT) fish was compared using microarrays. WT females and males exhibited 255 genes differentially expressed (DEG) but this difference was reduced to 31 after ASIP overexpression. Statistical analysis revealed 1122 DEG when considering only fish genotype but 1066 and 981 DEG when comparing ASIP males or females with their WT counterparts, respectively. Interaction between genotype and sex significantly affected the expression of 97 genes. Several neuronal systems involved in the control of food intake were identified which displayed a differential expression according to the genotype of the fish that unravelling the flow of melanocortinergic information through the central pathways that controls the energy balance. The information provided herein will help to elucidate new central systems involved in control of obesity and should be of invaluable use for sustaining fish production systems. PMID:27156808

  16. Compact tomato seedlings and plants upon overexpression of a tomato chromatin remodelling ATPase gene.

    Science.gov (United States)

    Folta, Adam; Bargsten, Joachim W; Bisseling, Ton; Nap, Jan-Peter; Mlynarova, Ludmila

    2016-02-01

    Control of plant growth is an important aspect of crop productivity and yield in agriculture. Overexpression of the AtCHR12/23 genes in Arabidopsis thaliana reduced growth habit without other morphological changes. These two genes encode Snf2 chromatin remodelling ATPases. Here, we translate this approach to the horticultural crop tomato (Solanum lycopersicum). We identified and cloned the single tomato ortholog of the two Arabidopsis Snf2 genes, designated SlCHR1. Transgenic tomato plants (cv. Micro-Tom) that constitutively overexpress the coding sequence of SlCHR1 show reduced growth in all developmental stages of tomato. This confirms that SlCHR1 combines the functions of both Arabidopsis genes in tomato. Compared to the wild type, the transgenic seedlings of tomato have significantly shorter roots, hypocotyls and reduced cotyledon size. Transgenic plants have a much more compact growth habit with markedly reduced plant height, severely compacted reproductive structures with smaller flowers and smaller fruits. The results indicate that either GMO-based or non-GMO-based approaches to modulate the expression of chromatin remodelling ATPase genes could develop into methods to control plant growth, for example to replace the use of chemical growth retardants. This approach is likely to be applicable and attractive for any crop for which growth habit reduction has added value. PMID:25974127

  17. Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

    International Nuclear Information System (INIS)

    The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors

  18. Identification of cytotoxic drugs that selectively target tumor cells with MYC overexpression.

    Directory of Open Access Journals (Sweden)

    Anna Frenzel

    Full Text Available Expression of MYC is deregulated in a wide range of human cancers, and is often associated with aggressive disease and poorly differentiated tumor cells. Identification of compounds with selectivity for cells overexpressing MYC would hence be beneficial for the treatment of these tumors. For this purpose we used cell lines with conditional MYCN or c-MYC expression, to screen a library of 80 conventional cytotoxic compounds for their ability to reduce tumor cell viability and/or growth in a MYC dependent way. We found that 25% of the studied compounds induced apoptosis and/or inhibited proliferation in a MYC-specific manner. The activities of the majority of these were enhanced both by c-MYC or MYCN over-expression. Interestingly, these compounds were acting on distinct cellular targets, including microtubules (paclitaxel, podophyllotoxin, vinblastine and topoisomerases (10-hydroxycamptothecin, camptothecin, daunorubicin, doxorubicin, etoposide as well as DNA, RNA and protein synthesis and turnover (anisomycin, aphidicholin, gliotoxin, MG132, methotrexate, mitomycin C. Our data indicate that MYC overexpression sensitizes cells to disruption of specific pathways and that in most cases c-MYC and MYCN overexpression have similar effects on the responses to cytotoxic compounds. Treatment of the cells with topoisomerase I inhibitors led to down-regulation of MYC protein levels, while doxorubicin and the small molecule MYRA-A was found to disrupt MYC-Max interaction. We conclude that the MYC pathway is only targeted by a subset of conventional cytotoxic drugs currently used in the clinic. Elucidating the mechanisms underlying their specificity towards MYC may be of importance for optimizing treatment of tumors with MYC deregulation. Our data also underscores that MYC is an attractive target for novel therapies and that cellular screenings of chemical libraries can be a powerful tool for identifying compounds with a desired biological activity.

  19. Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Young-Mi, E-mail: youngmi_ham@hms.harvard.edu [College of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States); Mahoney, Sarah Jane [Department of Cell Biology, Harvard Medical School, Boston, MA 02115 (United States)

    2013-06-10

    The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy. -- Highlights: • TRIM72 inhibits AKT signaling through ubiquitination of IRS-1 in cardiac cells. • TRIM72 regulates the size of cardiac cells. • TRIM72 regulates size of postnatal TRIM72-overexpressing transgenic mice hearts. • Adult TRIM72-overexpressing transgenic mice hearts showed cardiac dysfunction. • Adult TRIM72 transgenic mice hearts showed higher expression of endothelin receptors.

  20. HSP25 overexpression attenuates oxidative stress-induced apoptosis: role of ERK1/2 signaling and manganase superoxide dismutase

    International Nuclear Information System (INIS)

    Full text: HSP25 has been shown to induce resistance to radiation and oxidative stress. However, its exact mechanisms remain unclear. In the present study, high concentration of H 2 O 2 was found to induce DNA fragmentation in L929 mouse fibroblast cells, and HSP25 overexpression attenuated this phenomenon. To elucidate the mechanisms of H 2 O 2 mediated cell death, ERK1/2, p38-MAPK and JNK1/2 phosphorylation by H2O2were examined. ERK1/2 and JNK1/2 were activated by H2O2and ERK1/2 activation was inhibited in HSP25 overexpressed cells, while JNK1/2 was indifferent. Inhibition of ERK1/2 activation by treatment with PD98059 or dominant-negative ERK2 transfection blocked H2O2-induced cell death, while HSP25 overexpressed cells was not affected at all. Moreover, inhibition of JNK1/2 by dominant-negative JNK1 or JNK2, or MKK4 or MKK7 transfection did not affect H2O2-mediated cell death in control cells. Dominant negative Ras or Raf transfection inhibited H2O2-mediated ERK1/2 activation and cell death in control cells. On the contrary, HSP25 overexpressed cells did not show any differences. Upstream pathways of H2O2-mediated ERK1/2 activation and cell death were both tyrosine kinase (PDGF and receptor and Src) and PKC and, while these kinases did not respond by H2O2treatment in HSP25 overexpressed cells. Since HSP25 overexpression increased manganese superoxide dismutase (MnSOD) gene expression and enzyme activity, involvement of MnSOD in HSP25 mediated attenuation of H2O2-mediated ERK1/2 activation and cell death was examined. Blockage of MnSOD with antisense oligonucleotides prevented DNA fragmentation and returned the ERK1/2 activation to the control level. Indeed, when MnSOD was overexpressed in L929 cells, similar phenomenon to HSP25 overexpressed cells to reduce DNA fragmentation and ERK1/2 activation was observed. From the above results, we suggested for the first time that reduced oxidative damage by HSP25 was due to MnSOD-mediated downregulation of ERK1/2

  1. Overexpression of Robo2 causes defects in the recruitment of metanephric mesenchymal cells and ureteric bud branching morphogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Jiayao [Institute of Nephrology, State Key Laboratory of Kidney Disease (2011DAV00088), The Chinese PLA General Hospital, Beijing 100853 (China); Medical College of NanKai University, Tianjin (China); Li, Qinggang; Xie, Yuansheng; Zhang, Xueguang; Cui, Shaoyuan; Shi, Suozhu [Institute of Nephrology, State Key Laboratory of Kidney Disease (2011DAV00088), The Chinese PLA General Hospital, Beijing 100853 (China); Chen, Xiangmei, E-mail: xmchen301@126.com [Institute of Nephrology, State Key Laboratory of Kidney Disease (2011DAV00088), The Chinese PLA General Hospital, Beijing 100853 (China); Medical College of NanKai University, Tianjin (China)

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer Overexpression of Robo2 caused reduced UB branching and glomerular number. Black-Right-Pointing-Pointer Fewer MM cells surrounding the UB after overexpression of Robo2 in vitro. Black-Right-Pointing-Pointer No abnormal Epithelial Morphology of UB or apoptosis of mm cells in the kidney. Black-Right-Pointing-Pointer Overexpression of Robo2 affected MM cells migration and caused UB deficit. Black-Right-Pointing-Pointer The reduced glomerular number can also be caused by fewer MM cells. -- Abstract: Roundabout 2 (Robo2) is a member of the membrane protein receptor family. The chemorepulsive effect of Slit2-Robo2 signaling plays vital roles in nervous system development and neuron migration. Slit2-Robo2 signaling is also important for maintaining the normal morphogenesis of the kidney and urinary collecting system, especially for the branching of the ureteric bud (UB) at the proper site. Slit2 or Robo2 mouse mutants exhibit multilobular kidneys, multiple ureters, and dilatation of the ureter, renal pelvis, and collecting duct system, which lead to vesicoureteral reflux. To understand the effect of Robo2 on kidney development, we used microinjection and electroporation to overexpress GFP-Robo2 in an in vitro embryonic kidney model. Our results show reduced UB branching and decreased glomerular number after in vitro Robo2 overexpression in the embryonic kidneys. We found fewer metanephric mesenchymal (MM) cells surrounding the UB but no abnormal morphology in the branching epithelial UB. Meanwhile, no significant change in MM proliferation or apoptosis was observed. These findings indicate that Robo2 is involved in the development of embryonic kidneys and that the normal expression of Robo2 can help maintain proper UB branching and glomerular morphogenesis. Overexpression of Robo2 leads to reduced UB branching caused by fewer surrounding MM cells, but MM cell apoptosis is not involved in this effect. Our study demonstrates that

  2. Over-expression of ascorbate oxidase in the apoplast of transgenic tobacco results in altered ascorbate and glutathione redox states and increased sensitivity to ozone

    DEFF Research Database (Denmark)

    Sanmartin, Maite; Drogoudi, Pavlina D.; Lyons, Tom;

    2003-01-01

    redox state of ascorbate was reduced from 30% in wild-type leaves to below the threshold for detection in transgenic plants. Levels of ascorbic acid and glutathione in the symplast were not affected by AO overexpression, but the redox state of ascorbate was reduced, while that of glutathione was...

  3. Overexpression of miR-378 is frequent and may affect treatment outcomes in patients with acute myeloid leukemia.

    Science.gov (United States)

    Qian, Jun; Lin, Jiang; Qian, Wei; Ma, Ji-chun; Qian, Si-xuan; Li, Yun; Yang, Jing; Li, Jian-yong; Wang, Cui-zhu; Chai, Hai-yan; Chen, Xing-xing; Deng, Zhao-qun

    2013-07-01

    MicroRNA miR-378 plays important roles in tumorigenesis by enhancing cell survival, reducing apoptosis, promoting tumor growth, angiogenesis and promoting cell migration and invasion. Abnormal expression of miR-378 has been observed in various types of cancers. The aim of this study was to investigate the expression status of miR-378 and its clinical significance in patients with acute myeloid leukemia (AML) using real-time quantitative PCR. miR-378 overexpression was identified in 26 of 84 (31%) AML patients. The patients with miR-378 overexpression had lower hemoglobin level than those without miR-378 overexpression (66 versus 78 g/L, respectively, P=0.010). The frequency of miR-378 overexpression in FAB-M2 subtype was higher than other subtypes (44% versus 20%, P=0.032). Moreover, the frequency of miR-378 overexpression was higher in patients with t(8;21) than in others (64% versus 24%, P=0.012). The status of miR-378 expression was not correlated with the mutations of eight genes (FLT3-ITD, NPM1, C-KIT, IDH1/IDH2, DNMT3A, C/EBPA and U2AF1). The difference in relapse-free survival was observed between patients with and without miR-378 overexpression (P=0.049). These findings suggest that miR-378 up-regulation is a common event and might have an adverse impact on prognosis in AML. PMID:23582927

  4. SND1 overexpression deregulates cholesterol homeostasis in hepatocellular carcinoma.

    Science.gov (United States)

    Navarro-Imaz, Hiart; Rueda, Yuri; Fresnedo, Olatz

    2016-09-01

    SND1 is a multifunctional protein participating, among others, in gene transcription and mRNA metabolism. SND1 is overexpressed in cancer cells and promotes viability and tumourigenicity of hepatocellular carcinoma cells. This study shows that cholesterol synthesis is increased in SND1-overexpressing hepatoma cells. Neither newly synthesised nor extracellularly supplied cholesterol are able to suppress this increase; however, inhibition of cholesterol esterification reverted the activated state of sterol-regulatory element-binding protein 2 (SREBP2) and cholesterogenesis. These results highlight SND1 as a potential regulator of cellular cholesterol distribution and homeostasis in hepatoma cells, and support the rationale for the therapeutic use of molecules that influence cholesterol management when SND1 is overexpressed. PMID:27238764

  5. MIC3 over-expression reduces cotton susceptibility to root-knot nematode

    Science.gov (United States)

    The inheritance of root-knot nematode (RKN) resistance in cotton has been the focus of much research; however, the mechanism of the resistance at the molecular level remains largely unknown. To date, increased transcript and protein levels of MIC3 in galls of resistant plants remains the only examp...

  6. Hair Cell Overexpression of Islet1 Reduces Age-Related and Noise-Induced Hearing Loss

    OpenAIRE

    Huang, Mingqian; Kantardzhieva, Albena; Scheffer, Deborah; Liberman, M. Charles; Chen, Zheng-Yi

    2013-01-01

    Isl1 is a LIM-homeodomain transcription factor that is critical in the development and differentiation of multiple tissues. In the mouse inner ear, Isl1 is expressed in the prosensory region of otocyst, in young hair cells and supporting cells, and is no longer expressed in postnatal auditory hair cells. To evaluate how continuous Isl1 expression in postnatal hair cells affects hair cell development and cochlear function, we created a transgenic mouse model in which the Pou4f3 promoter drives...

  7. Hippocampal Neuroligin-2 Overexpression Leads to Reduced Aggression and Inhibited Novelty Reactivity in Rats

    OpenAIRE

    Kohl, Christine; Riccio, Orbicia; Grosse, Jocelyn; Zanoletti, Olivia; Fournier, Céline; Schmidt, Mathias V.; Sandi, Carmen

    2013-01-01

    Disturbances of the excitation/inhibition (E/I) balance in the brain were recently suggested as potential factors underlying disorders like autism and schizophrenia resulting in associated behavioral alterations including changes in social and emotional behavior as well as abnormal aggression. Neuronal cell adhesion molecules (nCAMs) and mutations in these genes were found to be strongly implicated in the pathophysiology of these disorders. Neuroligin2 (nlgn2) is a postsynaptic cell adhesion ...

  8. CD147 overexpression promotes tumorigenicity in Chinese hamster ovary cells.

    Science.gov (United States)

    Yong, Yu-Le; Liao, Cheng-Gong; Wei, Ding; Chen, Zhi-Nan; Bian, Huijie

    2016-04-01

    CD147 overexpresses in many epithelium-originated tumors and plays an important role in tumor migration and invasion. Most studies aim at the role of CD147 in tumor progression using tumor cell models. However, the influence of abnormal overexpression of CD147 on neoplastic transformation of normal cells is unknown. Here, the role of CD147 in malignant phenotype transformation in CHO cells was investigated. Three CHO cell lines that stably overexpressed CD147 (CHO-CD147), EGFP-CD147 (CHO-EGFP-CD147), and EGFP (CHO-EGFP) were generated by transfection of plasmids containing human CD147, EGFP-human CD147, and EGFP genes into CHO cells. Cell migration and invasion were detected by wound healing and transwell matrix penetration assay. Trypan blue exclusion, MTT, cell cycle analysis, and BrdU cell proliferation assay were used to detect cell viability and cell proliferation. Annexin V-FITC analysis was performed to detect apoptosis. We found that CD147 overexpression promoted the migration and invasion of CHO cells. CD147 accelerated the G1 to S phase transition and enhanced the CHO cell proliferation. Overexpression of CD147 inhibited both early- and late-stages of apoptosis of CHO-CD147 cells, which is caused by serum deprivation. CHO-EGFP-CD147 cells showed an increased anchorage-independent growth compared with CHO-EGFP cells as detected by soft-agar colony formation assay. The tumors formed by CHO-CD147 cells in nude mice were larger and coupled with higher expression of proliferating cell nuclear antigen and Ki-67 than that of CHO cells. In conclusion, human CD147 overexpression induces malignant phenotype in CHO cells. PMID:26676266

  9. Matrix metalloproteinase-8 overexpression prevents proper tissue repair

    DEFF Research Database (Denmark)

    Danielsen, Patricia L; Holst, Anders V; Maltesen, Henrik R; Bassi, Maria R; Holst, Peter J; Heinemeier, Katja M; Olsen, Jørgen; Danielsen, Carl Christian; Poulsen, Steen S; Jorgensen, Lars N; Agren, Magnus S

    2011-01-01

    The collagenolytic matrix metalloproteinase-8 (MMP-8) is essential for normal tissue repair but is often overexpressed in wounds with disrupted healing. Our aim was to study the impact of a local excess of this neutrophil-derived proteinase on wound healing using recombinant adenovirus-driven tra......The collagenolytic matrix metalloproteinase-8 (MMP-8) is essential for normal tissue repair but is often overexpressed in wounds with disrupted healing. Our aim was to study the impact of a local excess of this neutrophil-derived proteinase on wound healing using recombinant adenovirus...

  10. Effect of various levels of catalase antioxidant in semen extenders on lipid peroxidation and semen quality after the freeze-thawing bull semen

    Directory of Open Access Journals (Sweden)

    Reza Asadpour

    2011-11-01

    Full Text Available The objective of this study was to evaluate effect of different concentrations of catalase in two extenders on motility, viability and lipid peroxidation bull spermatozoa during semen freezing process. Thirty ejaculates collected from ten Holstein bulls were pooled and evaluated at 37 °C. Pool ejaculated was split into two main experimental groups, 1 and 2. In experiment 1, specimen was diluted to a final concentration of 30 × 106 spermatozoa with citrate-egg yolk and in experiment 2; specimen was diluted with tris-egg yolk extender to the same concentration. In both experiments diluted semen was divided into three aliquots, including a control and two test groups. Each aliquot was rediluted with an equal volume of extender either without (control or with one of the antioxidants contained one of the following antioxidants: catalase (CAT; 100 IU mL-1 catalase (CAT; 200 IU mL-1 and control group. No significant differences were observed in sperm viability and motility following addition of catalase enzyme at concentration of 100 IU mL-1 and 200 IU mL-1 to citrate-egg yolk extender. But the highest sperm viability was achieved by addition of 100 IU mL-1 and 200 IU mL-1 catalase to tris-egg yolk semen extender compared with the control group (P < 0.05. Malondialdehyde levels did not change with addition of catalase in both extenders compared with the control group. The obtained results provide a new approach to the cryopreservation of bull semen, and could positively contribute to intensive cattle production.

  11. Mipu1 overexpression protects macrophages from oxLDL-induced foam cell formation and cell apoptosis.

    Science.gov (United States)

    Qu, Shun-Lin; Fan, Wen-Jing; Zhang, Chi; Guo, Fang; Han, Dan; Pan, Wen-Jun; Li, Wei; Feng, Da-Ming; Jiang, Zhi-Sheng

    2014-12-01

    Mipu1 (myocardial ischemic preconditioning upregulated protein 1) is a novel N-terminal Kruppel-associated box (KRAB)/C2H2 zinc finger superfamily protein, that displays a powerful effect in protecting H9c2 cells from oxidative stress-induced cell apoptosis. The present study aims to investigate the effect of Mipu1 overexpression on oxidized low-density lipoprotein (oxLDL)-induced foam cell formation, cell apoptosis, and its possible mechanisms. New Zealand healthy rabbits were used to establish atherosclerosis model, and serum levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were detected by an automatic biochemical analyzer. Sudan IV staining was used to detect atherosclerotic lesions. The RAW264.7 macrophage cell line was selected as the experimental material. Oil red O staining, high-performance liquid chromatography, and Dil-labeled lipoprotein were used to detect cholesterol accumulation qualitatively and quantitatively, respectively. Flow cytometry was used to determine cell apoptosis. Real-time quantitative polymerase chain reaction (PCR) was used to detect the mRNA expression of the main proteins that are associated with the transport of cholesterol, such as ABCA1, ABCG1, SR-BI, and CD36. Western blot analysis was used to detect the protein expression of Mipu1. There were atherosclerotic lesions in the high-fat diet group with Sudan IV staining. High-fat diet decreased Mipu1 expression and increased CD36 expression significantly at the 10th week compared with standard-diet rabbits. Mipu1 overexpression decreased oxLDL-induced cholesterol accumulation, oxLDL uptake, cell apoptosis, and cleaved caspase-3. Mipu1 overexpression inhibited the oxLDL-induced CD36 mRNA and protein expression, but it did not significantly inhibit the mRNA expression of ABCA1, ABCG1, and SR-BI. Mipu1 overexpression inhibits oxLDL-induced foam cell formation and cell apoptosis. Mipu1 overexpression reduces the

  12. Hinokitiol Exerts Anticancer Activity through Downregulation of MMPs 9/2 and Enhancement of Catalase and SOD Enzymes: In Vivo Augmentation of Lung Histoarchitecture

    Directory of Open Access Journals (Sweden)

    Chien-Hsun Huang

    2015-09-01

    Full Text Available Melanoma is extremely resistant to chemotherapy and the death rate is increasing hastily worldwide. Extracellular matrix promotes the migration and invasion of tumor cells through the production of matrix metalloproteinase (MMP-2 and -9. Evidence has shown that natural dietary antioxidants are capable of inhibiting cancer cell growth. Our recent studies showed that hinokitiol, a natural bioactive compound, inhibited vascular smooth muscle cell proliferation and platelets aggregation. The present study is to investigate the anticancer efficacy of hinokitiol against B16-F10 melanoma cells via modulating tumor invasion factors MMPs, antioxidant enzymes in vitro. An in vivo mice model of histological investigation was performed to study the patterns of elastic and collagen fibers. Hinokitiol inhibited the expression and activity of MMPs-2 and -9 in B16-F10 melanoma cells, as measured by western blotting and gelatin zymography, respectively. An observed increase in protein expression of MMPs 2/9 in melanoma cells was significantly inhibited by hinokitiol. Notably, hinokitiol (1–5 μM increased the activities of antioxidant enzymes catalase (CAT and superoxide dismutase (SOD from the reduction in melanoma cells. Also, hinokitiol (2–10 µM concentration dependently reduced in vitro Fenton reaction induced hydroxyl radical (OH· formation. An in vivo study showed that hinokitiol treatment increased elastic fibers (EF, collagens dispersion, and improved alveolar alterations in the lungs of B16/F10 injected mice. Overall, our findings propose that hinokitiol may be a potent anticancer candidate through down regulation of MMPs 9/2, reduction of OH· production and enhancement of antioxidant enzymes SOD and CAT.

  13. Atherosclerosis in aged mice over-expressing the reverse cholesterol transport genes

    Directory of Open Access Journals (Sweden)

    J.A. Berti

    2005-03-01

    Full Text Available We determined whether over-expression of one of the three genes involved in reverse cholesterol transport, apolipoprotein (apo AI, lecithin-cholesterol acyl transferase (LCAT and cholesteryl ester transfer protein (CETP, or of their combinations influenced the development of diet-induced atherosclerosis. Eight genotypic groups of mice were studied (AI, LCAT, CETP, LCAT/AI, CETP/AI, LCAT/CETP, LCAT/AI/CETP, and non-transgenic after four months on an atherogenic diet. The extent of atherosclerosis was assessed by morphometric analysis of lipid-stained areas in the aortic roots. The relative influence (R² of genotype, sex, total cholesterol, and its main sub-fraction levels on atherosclerotic lesion size was determined by multiple linear regression analysis. Whereas apo AI (R² = 0.22, P < 0.001 and CETP (R² = 0.13, P < 0.01 expression reduced lesion size, the LCAT (R² = 0.16, P < 0.005 and LCAT/AI (R² = 0.13, P < 0.003 genotypes had the opposite effect. Logistic regression analysis revealed that the risk of developing atherosclerotic lesions greater than the 50th percentile was 4.3-fold lower for the apo AI transgenic mice than for non-transgenic mice, and was 3.0-fold lower for male than for female mice. These results show that apo AI overexpression decreased the risk of developing large atherosclerotic lesions but was not sufficient to reduce the atherogenic effect of LCAT when both transgenes were co-expressed. On the other hand, CETP expression was sufficient to eliminate the deleterious effect of LCAT and LCAT/AI overexpression. Therefore, increasing each step of the reverse cholesterol transport per se does not necessarily imply protection against atherosclerosis while CETP expression can change specific athero genic scenarios.

  14. Prohibitin overexpression improves myocardial function in diabetic cardiomyopathy.

    Science.gov (United States)

    Dong, Wen-Qian; Chao, Min; Lu, Qing-Hua; Chai, Wei-Li; Zhang, Wei; Chen, Xue-Ying; Liang, Er-Shun; Wang, Ling-Bo; Tian, Hong-Liang; Chen, Yu-Guo; Zhang, Ming-Xiang

    2016-01-01

    Prohibitin (PHB) is a highly conserved protein implicated in various cellular functions including proliferation, apoptosis, tumor suppression, transcription, and mitochondrial protein folding. However, its function in diabetic cardiomyopathy (DCM) is still unclear. In vivo, type 2 diabetic rat model was induced by using a high-fat diet and low-dose streptozotocin. Overexpression of the PHB protein in the model rats was achieved by injecting lentivirus carrying PHB cDNA via the jugular vein. Characteristics of type 2 DCM were evaluated by metabolic tests, echocardiography and histopathology. Rats with DCM showed severe insulin resistance, left ventricular dysfunction, fibrosis and apoptosis. PHB overexpression ameliorated the disease. Cardiofibroblasts (CFs) and H9c2 cardiomyoblasts were used in vitro to investigate the mechanism of PHB in altered function. In CFs treated with HG, PHB overexpression decreased expression of collagen, matrix metalloproteinase activity, and proliferation. In H9c2 cardiomyoblasts, PHB overexpression inhibited apoptosis induced by HG. Furthermore, the increased phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 was significantly decreased and the inhibited phosphorylation of Akt was restored in DCM. Therefore, PHB may be a new therapeutic target for human DCM. PMID:26623724

  15. Brain phenotype of transgenic mice overexpressing cystathionine β-synthase.

    Directory of Open Access Journals (Sweden)

    Vinciane Régnier

    Full Text Available BACKGROUND: The cystathionine β-synthase (CBS gene, located on human chromosome 21q22.3, is a good candidate for playing a role in the Down Syndrome (DS cognitive profile: it is overexpressed in the brain of individuals with DS, and it encodes a key enzyme of sulfur-containing amino acid (SAA metabolism, a pathway important for several brain physiological processes. METHODOLOGY/PRINCIPAL FINDINGS: Here, we have studied the neural consequences of CBS overexpression in a transgenic mouse line (60.4P102D1 expressing the human CBS gene under the control of its endogenous regulatory regions. These mice displayed a ∼2-fold increase in total CBS proteins in different brain areas and a ∼1.3-fold increase in CBS activity in the cerebellum and the hippocampus. No major disturbance of SAA metabolism was observed, and the transgenic mice showed normal behavior in the rotarod and passive avoidance tests. However, we found that hippocampal synaptic plasticity is facilitated in the 60.4P102D1 line. CONCLUSION/SIGNIFICANCE: We demonstrate that CBS overexpression has functional consequences on hippocampal neuronal networks. These results shed new light on the function of the CBS gene, and raise the interesting possibility that CBS overexpression might have an advantageous effect on some cognitive functions in DS.

  16. Overexpression, Purification, Characterization, and Pathogenicity of Vibrio harveyi Hemolysin VHH

    Science.gov (United States)

    Zhong, Yingbin; Zhang, Xiao-Hua; Chen, Jixiang; Chi, Zhenghao; Sun, Boguang; Li, Yun; Austin, Brian

    2006-01-01

    Vibrio harveyi VHH hemolysin is a putative pathogenicity factor in fish. In this study, the hemolysin gene vhhA was overexpressed in Escherichia coli, and the purified VHH was characterized with regard to pH and temperature profiles, phospholipase activity, cytotoxicity, pathogenicity to flounder, and the signal peptide. PMID:16988279

  17. Co-overexpressing a Plasma Membrane and a Vacuolar Membrane Sodium/Proton Antiporter Significantly Improves Salt Tolerance in Transgenic Arabidopsis Plants

    Science.gov (United States)

    Pehlivan, Necla; Sun, Li; Jarrett, Philip; Yang, Xiaojie; Mishra, Neelam; Chen, Lin; Kadioglu, Asim; Shen, Guoxin; Zhang, Hong

    2016-01-01

    The Arabidopsis gene AtNHX1 encodes a vacuolar membrane-bound sodium/proton (Na+/H+) antiporter that transports Na+ into the vacuole and exports H+ into the cytoplasm. The Arabidopsis gene SOS1 encodes a plasma membrane-bound Na+/H+ antiporter that exports Na+ to the extracellular space and imports H+ into the plant cell. Plants rely on these enzymes either to keep Na+ out of the cell or to sequester Na+ into vacuoles to avoid the toxic level of Na+ in the cytoplasm. Overexpression of AtNHX1 or SOS1 could improve salt tolerance in transgenic plants, but the improved salt tolerance is limited. NaCl at concentration >200 mM would kill AtNHX1-overexpressing or SOS1-overexpressing plants. Here it is shown that co-overexpressing AtNHX1 and SOS1 could further improve salt tolerance in transgenic Arabidopsis plants, making transgenic Arabidopsis able to tolerate up to 250 mM NaCl treatment. Furthermore, co-overexpression of AtNHX1 and SOS1 could significantly reduce yield loss caused by the combined stresses of heat and salt, confirming the hypothesis that stacked overexpression of two genes could substantially improve tolerance against multiple stresses. This research serves as a proof of concept for improving salt tolerance in other plants including crops. PMID:26985021

  18. The overexpressed human 46-kDa mannose 6-phosphate receptor mediates endocytosis and sorting of β-glucuronidase

    International Nuclear Information System (INIS)

    The authors studied the function of the human small (46-kDa) mannose 6-phosphate receptor (SMPR) in transfected mouse L cells that do not express the larger insulin-like growth factor II/mannose 6-phosphate receptor. Cells overexpressing human SMPR were studied for enzyme binding to cell surface receptors, for binding to intracellular receptors in permeabilized cells, and for receptor-mediated endocytosis of recombinant human β-glucuronidase. Specific binding to human SMPR in permeabilized cells showed a pH optimum between pH 6.0 and pH 6.5. Binding was significant in the present of EDTA but was enhanced by added divalent cations. Up to 2.3% of the total functional receptor could be detected on the cell surface by enzyme binding. They present experiments showing that at very high levels of overexpression, and at pH 6.5, human SMPR mediated the endocytosis of β-glucuronidase. At pH 7.5, the rate of endocytosis was only 14% the rate seen at pH 6.5. Cells overexpressing human SMPR also showed reduced secretion of newly synthesized β-glucuronidase when compared to cells transfected with vector only, suggesting that overexpressed human SMPR can participate in sorting of newly synthesized β-glucuronidase and partially correct the sorting defect in mouse L cells that do not express the insulin-like growth factor II/mannose 6-phosphate receptor

  19. Over-Expression of SlSHN1 Gene Improves Drought Tolerance by Increasing Cuticular Wax Accumulation in Tomato

    Directory of Open Access Journals (Sweden)

    Ayed M. Al-Abdallat

    2014-10-01

    Full Text Available Increasing cuticular wax accumulation in plants has been associated with improving drought tolerance in plants. In this study, a cDNA clone encoding the SlSHN1 transcription factor, the closest ortholog to WIN/SHN1 gene in Arabidopsis, was isolated from tomato plant. Expression analysis of SlSHN1 indicated that it is induced in response to drought conditions. The over-expression of SlSHN1 in tomato under the control of the constitutive CaMV 35S promoter produced plants that showed mild growth retardation phenotype with shiny and dark green leaves. Scanning electron microscopy showed that the over-expression of SlSHN1 in tomato resulted in higher cuticular wax deposition on leaf epidermial tissue when compared to non-transformed plants. Expression analysis in transgenic lines over-expressing SlSHN1 indicated that several wax-related synthesis genes were induced. Transgenic tomato plants over-expressing SlSHN1 showed higher drought tolerance when compared with wild type plants; this was reflected in delayed wilting of transgenic lines, improved water status and reduced water loss rate when compared with wild type plants. In conclusion, the SlSHN1 gene can modulate wax accumulation and could be utilized to enhance drought tolerance in tomato plant.

  20. Effect of Lead (Pb Exposure on the Activity of Superoxide Dismutase and Catalase in Battery Manufacturing Workers (BMW of Western Maharashtra (India with Reference to Heme biosynthesis

    Directory of Open Access Journals (Sweden)

    Kusal K. Das

    2006-12-01

    Full Text Available The aim of this study was to estimate the activity of superoxide dismutase (SOD and catalase in erythrocytes and malondialdehyde (MDA in plasma of battery manufacturing workers (BMW of Western Maharashtra (India who were occupationally exposed to lead (Pb over a long period of time (about 15 years. This study was also aimed to determine the Pb intoxication resulted in a disturbance of heme biosynthesis in BMW group. The blood Pb level of BMW group (n = 28 was found to be in the range of 25.8 – 78.0 μg/dL (mean + SD, 53.63 + 16.98 whereas in Pb unexposed control group (n = 35 the range was 2.8 – 22.0 μg/dL (mean + SD, 12.52 + 4.08. The blood level (Pb-B and urinary lead level (Pb-U were significantly increased in BMW group as compared to unexposed control. Though activated d- aminolevulinic acid dehydratase (ALAD activities in BMW group did not show any significant change when compared to control group but activated / non activated erythrocyte – ALAD activities in BMW group showed a significant increase. Erythrocyte- zinc protoporphyrin (ZPP, urinary daminolevulinic acid (ALA-U and porphobilinogen (PBG-U of BMW groups elevated significantly as compared to control. A positive correlation (r = 0.66, p 1.0 were observed in control group. Hematological study revealed a significant decrease of hemoglobin concentration, packed cell volume (% and other blood indices and a significant increase of total leucocytes count in BMW group in comparison to control group. The serum MDA content was significantly increased (p< 0.001 and the activities of antioxidant enzymes such as erythrocyte- SOD (p< 0.001 and erythrocytecatalase (p< 0.001 were significantly reduced in BMW group as compared to control group. A positive correlation (r = 0.45, p<0.02 between Pb-B and serum MDA level was observed in BMW group (Pb-B range 25.8 – 78.0 μg / dL but such significant correlation did not notice in

  1. Singlet oxygen treatment of tumor cells triggers extracellular singlet oxygen generation, catalase inactivation and reactivation of intercellular apoptosis-inducing signaling.

    Science.gov (United States)

    Riethmüller, Michaela; Burger, Nils; Bauer, Georg

    2015-12-01

    Intracellular singlet oxygen generation in photofrin-loaded cells caused cell death without discrimination between nonmalignant and malignant cells. In contrast, extracellular singlet oxygen generation caused apoptosis induction selectively in tumor cells through singlet oxygen-mediated inactivation of tumor cell protective catalase and subsequent reactivation of intercellular ROS-mediated apoptosis signaling through the HOCl and the NO/peroxynitrite signaling pathway. Singlet oxygen generation by extracellular photofrin alone was, however, not sufficient for optimal direct inactivation of catalase, but needed to trigger the generation of cell-derived extracellular singlet oxygen through the interaction between H2O2 and peroxynitrite. Thereby, formation of peroxynitrous acid, generation of hydroxyl radicals and formation of perhydroxyl radicals (HO2(.)) through hydroxyl radical/H2O2 interaction seemed to be required as intermediate steps. This amplificatory mechanism led to the formation of singlet oxygen at a sufficiently high concentration for optimal inactivation of membrane-associated catalase. At low initial concentrations of singlet oxygen, an additional amplification step needed to be activated. It depended on singlet oxygen-dependent activation of the FAS receptor and caspase-8, followed by caspase-8-mediated enhancement of NOX activity. The biochemical mechanisms described here might be considered as promising principle for the development of novel approaches in tumor therapy that specifically direct membrane-associated catalase of tumor cells and thus utilize tumor cell-specific apoptosis-inducing ROS signaling. PMID:26225731

  2. Effect of drought stress and subsequent recovery on protein, carbohydrate contents, catalase and peroxidase activities in three chickpea (Cicer arietinum) cultivars

    NARCIS (Netherlands)

    Mafakheri, A.; Siosemardeh, A.; Bahramnejad, B.; Struik, P.C.; Sohrabi, Y.

    2011-01-01

    Drought stress is one of the major abiotic stresses in agriculture worldwide. This study was carried out to investigate the effects of drought stress and subsequent recovery on protein, carbohydrate content, catalase (CAT), and peroxidase (POX) activities in three varieties of chickpea (drought tole

  3. Growth retardation, reduced invasiveness, and impaired colistin-mediated cell death associated with colistin resistance development in Acinetobacter baumannii.

    Science.gov (United States)

    Pournaras, Spyros; Poulou, Aggeliki; Dafopoulou, Konstantina; Chabane, Yassine Nait; Kristo, Ioulia; Makris, Demosthenes; Hardouin, Julie; Cosette, Pascal; Tsakris, Athanassios; Dé, Emmanuelle

    2014-01-01

    Two colistin-susceptible/colistin-resistant (Col(s)/Col(r)) pairs of Acinetobacter baumannii strains assigned to international clone 2, which is prevalent worldwide, were sequentially recovered from two patients after prolonged colistin administration. Compared with the respective Col(s) isolates (Ab248 and Ab299, both having a colistin MIC of 0.5 μg/ml), both Col(r) isolates (Ab249 and Ab347, with colistin MICs of 128 and 32 μg/ml, respectively) significantly overexpressed pmrCAB genes, had single-amino-acid shifts in the PmrB protein, and exhibited significantly slower growth. The Col(r) isolate Ab347, tested by proteomic analysis in comparison with its Col(s) counterpart Ab299, underexpressed the proteins CsuA/B and C from the csu operon (which is necessary for biofilm formation). This isolate also underexpressed aconitase B and different enzymes involved in the oxidative stress response (KatE catalase, superoxide dismutase, and alkyl hydroperoxide reductase), suggesting a reduced response to reactive oxygen species (ROS) and, consequently, impaired colistin-mediated cell death through hydroxyl radical production. Col(s) isolates that were indistinguishable by macrorestriction analysis from Ab299 caused six sequential bloodstream infections, and isolates indistinguishable from Ab248 caused severe soft tissue infection, while Col(r) isolates indistinguishable from Ab347 and Ab249 were mainly colonizers. In particular, a Col(s) isolate identical to Ab299 was still invading the bloodstream 90 days after the colonization of this patient by Col(r) isolates. These observations indicate considerably lower invasiveness of A. baumannii clinical isolates following the development of colistin resistance. PMID:24247145

  4. Regulation, overexpression, and target gene identification of Potato Homeobox 15 (POTH15) - a class-I KNOX gene in potato.

    Science.gov (United States)

    Mahajan, Ameya S; Kondhare, Kirtikumar R; Rajabhoj, Mohit P; Kumar, Amit; Ghate, Tejashree; Ravindran, Nevedha; Habib, Farhat; Siddappa, Sundaresha; Banerjee, Anjan K

    2016-07-01

    Potato Homeobox 15 (POTH15) is a KNOX-I (Knotted1-like homeobox) family gene in potato that is orthologous to Shoot Meristemless (STM) in Arabidopsis. Despite numerous reports on KNOX genes from different species, studies in potato are limited. Here, we describe photoperiodic regulation of POTH15, its overexpression phenotype, and identification of its potential targets in potato (Solanum tuberosum ssp. andigena). qRT-PCR analysis showed a higher abundance of POTH15 mRNA in shoot tips and stolons under tuber-inducing short-day conditions. POTH15 promoter activity was detected in apical and axillary meristems, stolon tips, tuber eyes, and meristems of tuber sprouts, indicating its role in meristem maintenance and leaf development. POTH15 overexpression altered multiple morphological traits including leaf and stem development, leaflet number, and number of nodes and branches. In particular, the rachis of the leaf was completely reduced and leaves appeared as a bouquet of leaflets. Comparative transcriptomic analysis of 35S::GUS and two POTH15 overexpression lines identified more than 6000 differentially expressed genes, including 2014 common genes between the two overexpression lines. Functional analysis of these genes revealed their involvement in responses to hormones, biotic/abiotic stresses, transcription regulation, and signal transduction. qRT-PCR of selected candidate target genes validated their differential expression in both overexpression lines. Out of 200 randomly chosen POTH15 targets, 173 were found to have at least one tandem TGAC core motif, characteristic of KNOX interaction, within 3.0kb in the upstream sequence of the transcription start site. Overall, this study provides insights to the role of POTH15 in controlling diverse developmental processes in potato. PMID:27217546

  5. Bacterial lipoprotein-induced tolerance is reversed by overexpression of IRAK-1.

    LENUS (Irish Health Repository)

    Li, Chong Hui

    2012-03-01

    Tolerance to bacterial cell wall components including bacterial lipoprotein (BLP) represents an essential regulatory mechanism during bacterial infection. Reduced Toll-like receptor 2 (TLR2) and IL-1 receptor-associated kinase 1 (IRAK-1) expression is a characteristic of the downregulated TLR signaling pathway observed in BLP-tolerised cells. In this study, we attempted to clarify whether TLR2 and\\/or IRAK-1 are the key molecules responsible for BLP-induced tolerance. Transfection of HEK293 cells and THP-1 cells with the plasmid encoding TLR2 affected neither BLP tolerisation-induced NF-κB deactivation nor BLP tolerisation-attenuated pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) production, indicating that BLP tolerance develops despite overexpression of TLR2 in these cells. In contrast, overexpression of IRAK-1 reversed BLP-induced tolerance, as transfection of IRAK-1 expressing vector resulted in a dose-dependent NF-κB activation and TNF-α release in BLP-tolerised cells. Furthermore, BLP-tolerised cells exhibited markedly repressed NF-κB p65 phosphorylation and impaired binding of p65 to several pro-inflammatory cytokine gene promoters including TNF-α and interleukin-6 (IL-6). Overexpression of IRAK-1 restored the nuclear transactivation of p65 at both TNF-α and IL-6 promoters. These results indicate a crucial role for IRAK-1 in BLP-induced tolerance, and suggest IRAK-1 as a potential target for manipulation of the TLR-mediated inflammatory response during microbial sepsis.

  6. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Institute of Scientific and Technical Information of China (English)

    Jun-Fei; Gu; Ming; Qiu; Jian-Chang; Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.

  7. Overexpression of mtDNA-associated AtWhy2 compromises mitochondrial function

    Directory of Open Access Journals (Sweden)

    Abou-Rached Charbel

    2008-04-01

    Full Text Available Abstract Background StWhy1, a member of the plant-specific Whirly single-stranded DNA-binding protein family, was first characterized as a transcription factor involved in the activation of the nuclear PR-10a gene following defense-related stress in potato. In Arabidopsis thaliana, Whirlies have recently been shown to be primarily localized in organelles. Two representatives of the family, AtWhy1 and AtWhy3 are imported into plastids while AtWhy2 localizes to mitochondria. Their function in organelles is currently unknown. Results To understand the role of mitochondrial Whirlies in higher plants, we produced A. thaliana lines with altered expression of the atwhy2 gene. Organellar DNA immunoprecipitation experiments demonstrated that AtWhy2 binds to mitochondrial DNA. Overexpression of atwhy2 in plants perturbs mitochondrial function by causing a diminution in transcript levels and mtDNA content which translates into a low activity level of respiratory chain complexes containing mtDNA-encoded subunits. This lowered activity of mitochondria yielded plants that were reduced in size and had distorted leaves that exhibited accelerated senescence. Overexpression of atwhy2 also led to early accumulation of senescence marker transcripts in mature leaves. Inactivation of the atwhy2 gene did not affect plant development and had no detectable effect on mitochondrial morphology, activity of respiratory chain complexes, transcription or the amount of mtDNA present. This lack of phenotype upon abrogation of atwhy2 expression suggests the presence of functional homologues of the Whirlies or the activation of compensating mechanisms in mitochondria. Conclusion AtWhy2 is associated with mtDNA and its overexpression results in the production of dysfunctional mitochondria. This report constitutes the first evidence of a function for the Whirlies in organelles. We propose that they could play a role in the regulation of the gene expression machinery of organelles.

  8. Overexpressing CYP71Z2 enhances resistance to bacterial blight by suppressing auxin biosynthesis in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available The hormone auxin plays an important role not only in the growth and development of rice, but also in its defense responses. We've previously shown that the P450 gene CYP71Z2 enhances disease resistance to pathogens through regulation of phytoalexin biosynthesis in rice, though it remains unclear if auxin is involved in this process or not.The expression of CYP71Z2 was induced by Xanthomonas oryzae pv. oryzae (Xoo inoculation was analyzed by qRT-PCR, with GUS histochemical staining showing that CYP71Z2 expression was limited to roots, blades and nodes. Overexpression of CYP71Z2 in rice durably and stably increased resistance to Xoo, though no significant difference in disease resistance was detected between CYP71Z2-RNA interference (RNAi rice and wild-type. Moreover, IAA concentration was determined using the HPLC/electrospray ionization/tandem mass spectrometry system. The accumulation of IAA was significantly reduced in CYP71Z2-overexpressing rice regardless of whether plants were inoculated or not, whereas it was unaffected in CYP71Z2-RNAi rice. Furthermore, the expression of genes related to IAA, expansin and SA/JA signaling pathways was suppressed in CYP71Z2-overexpressing rice with or without inoculation.These results suggest that CYP71Z2-mediated resistance to Xoo may be via suppression of IAA signaling in rice. Our studies also provide comprehensive insight into molecular mechanism of resistance to Xoo mediated by IAA in rice. Moreover, an available approach for understanding the P450 gene functions in interaction between rice and pathogens has been provided.

  9. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Directory of Open Access Journals (Sweden)

    Jun-Fei Gu

    2013-12-01

    Full Text Available Maize-specific pyruvate orthophosphate dikinase (PPDK was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK. The wild-type (WT cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW, moderate drought (MD and severe drought (SD, were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities, biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines (PPDK and PCK were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by 45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%, 20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments, respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase (PEPC and carbonic anhydrase (CA in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4 photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to drought-tolerance breeding via overexpression of C4 enzymes in rice.

  10. 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

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti

    2013-06-01

    Full Text Available 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 μg/kg, bolus and a depressor dose of sodium nitroprusside (50 μg/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 μL 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.

  11. Overexpression of esterase D in kidney from trisomy 13 fetuses

    Energy Technology Data Exchange (ETDEWEB)

    Loughna, S.; Moore, G. (Institute of Obstetrics and Gynaecology, London (United Kingdom)); Gau, G.; Blunt, S. (Cytogenetics Lab., London (United Kingdom)); Nicolaides, K. (King' s College School of Medicine and Dentistry, London (United Kingdom))

    1993-10-01

    Human trisomy 13 (Patau syndrome) occurs in approximately 1 in 5,000 live births. It is compatible with life, but prolonged survival is rare. Anomalies often involve the urogenital, cardiac, craniofacial, and central nervous systems. It is possible that these abnormalities may be due to the overexpression of developmentally important genes on chromosome 13. The expression of esterase D (localized to chromosome 13q14.11) has been investigated in both muscle and kidney from trisomy 13 fetuses and has been compared with normal age- and sex-matched fetal tissues, by using northern analysis. More than a twofold increase in expression of esterase D was found in the kidney of two trisomy 13 fetuses, with normal levels in a third. Overexpression was not seen in the muscle tissues from these fetuses. 34 refs., 3 figs., 2 tabs.

  12. Overexpression of kinesins mediates docetaxel resistance in breast cancer cells.

    Science.gov (United States)

    De, Sarmishtha; Cipriano, Rocky; Jackson, Mark W; Stark, George R

    2009-10-15

    Resistance to chemotherapy remains a major barrier to the successful treatment of cancer. To understand mechanisms underlying docetaxel resistance in breast cancer, we used an insertional mutagenesis strategy to identify proteins whose overexpression confers resistance. A strong promoter was inserted approximately randomly into the genomes of tumor-derived breast cancer cells, using a novel lentiviral vector. We isolated a docetaxel-resistant clone in which the level of the kinesin KIFC3 was elevated. When KIFC3 or the additional kinesins KIFC1, KIF1A, or KIF5A were overexpressed in the breast cancer cell lines MDA-MB231 and MDA-MB 468, the cells became more resistant to docetaxel. The binding of kinesins to microtubules opposes the stabilizing effect of docetaxel that prevents cytokinesis and leads to apoptosis. Our finding that kinesins can mediate docetaxel resistance might lead to novel therapeutic approaches in which kinesin inhibitors are paired with taxanes. PMID:19789344

  13. Trichostatin A suppresses lung adenocarcinoma development in Grg1 overexpressing transgenic mice

    International Nuclear Information System (INIS)

    Trichostatin A (TSA) is a histone deacetylase inhibitor and a potential therapeutic for various malignancies. The in vivo effect of TSA, however, has not been investigated in a transgenic lung cancer model. Previously, we generated transgenic mice with overexpression of Groucho-related-gene 1 (Grg1) and these mice all developed mucinous lung adenocarcinoma. Grg1 is a transcriptional co-repressor protein, the function of which is thought to depend on HDAC activity. However, functions outside the nucleus have also been proposed. We tested the supposition that Grg1-induced tumorigenesis is HDAC-dependent by assaying the therapeutic effect of TSA in the Grg1 transgenic mouse model. We found that TSA significantly inhibited lung tumorigenesis in Grg1 transgenic mice (p < 0.01). TSA did not affect overall Grg1 protein levels, but instead reduced ErbB1 and ErbB2 expression, which are upregulated by Grg1 in the absence of TSA. We confirmed this effect in A549 cells. Furthermore, lapatinib, an inhibitor of both ErbB1 and ErbB2, effectively masked the effect of TSA on the inhibition of A549 cell proliferation and migration, suggesting TSA does work, at least in part, by downregulating ErbB receptors. We additionally found that TSA reduced the expression of VEGF and VEGFR2, but not basic FGF and FGFR1. Our findings indicate that TSA effectively inhibits Grg1-induced lung tumorigenesis through the down-regulation of ErbB1 and ErbB2, as well as reduced VEGF signaling. This suggests TSA and other HDAC inhibitors could have therapeutic value in the treatment of lung cancers with Grg1 overexpression. - Highlights: • TSA suppresses lung tumorigenesis in Grg1 overexpressing transgenic mice. • TSA does not affect overall Grg1 protein levels in the mice and in A549 cells. • TSA reduces ErbB1 and ErbB2 expression in the mice and in A549 cells. • Lapatinib masks TSA-induced inhibition of A549 cell proliferation and migration. • TSA inhibits VEGF signaling, but not basic FGF

  14. Trichostatin A suppresses lung adenocarcinoma development in Grg1 overexpressing transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ju, E-mail: ju.liu@sdu.edu.cn [Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan (China); Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Li, Yan [Children' s Health Care Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong 250014 (China); Dong, Fengyun; Li, Liqun [Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan (China); Masuda, Takahiro; Allen, Thaddeus D. [Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Lobe, Corrinne G. [Molecular and Cellular Biology Division, Sunnybrook Health Science Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5 (Canada); Miami Mice Research Corp., MaRS Centre, Heritage Bldg., 101 College Street, Toronto, Ontario M5G 1L7 (Canada)

    2015-08-07

    Trichostatin A (TSA) is a histone deacetylase inhibitor and a potential therapeutic for various malignancies. The in vivo effect of TSA, however, has not been investigated in a transgenic lung cancer model. Previously, we generated transgenic mice with overexpression of Groucho-related-gene 1 (Grg1) and these mice all developed mucinous lung adenocarcinoma. Grg1 is a transcriptional co-repressor protein, the function of which is thought to depend on HDAC activity. However, functions outside the nucleus have also been proposed. We tested the supposition that Grg1-induced tumorigenesis is HDAC-dependent by assaying the therapeutic effect of TSA in the Grg1 transgenic mouse model. We found that TSA significantly inhibited lung tumorigenesis in Grg1 transgenic mice (p < 0.01). TSA did not affect overall Grg1 protein levels, but instead reduced ErbB1 and ErbB2 expression, which are upregulated by Grg1 in the absence of TSA. We confirmed this effect in A549 cells. Furthermore, lapatinib, an inhibitor of both ErbB1 and ErbB2, effectively masked the effect of TSA on the inhibition of A549 cell proliferation and migration, suggesting TSA does work, at least in part, by downregulating ErbB receptors. We additionally found that TSA reduced the expression of VEGF and VEGFR2, but not basic FGF and FGFR1. Our findings indicate that TSA effectively inhibits Grg1-induced lung tumorigenesis through the down-regulation of ErbB1 and ErbB2, as well as reduced VEGF signaling. This suggests TSA and other HDAC inhibitors could have therapeutic value in the treatment of lung cancers with Grg1 overexpression. - Highlights: • TSA suppresses lung tumorigenesis in Grg1 overexpressing transgenic mice. • TSA does not affect overall Grg1 protein levels in the mice and in A549 cells. • TSA reduces ErbB1 and ErbB2 expression in the mice and in A549 cells. • Lapatinib masks TSA-induced inhibition of A549 cell proliferation and migration. • TSA inhibits VEGF signaling, but not basic FGF

  15. Clinical significance of Phosphatidyl Inositol Synthase overexpression in oral cancer

    OpenAIRE

    Srivastava Anurag; Shukla Nootan K; DattaGupta Siddartha; Sawhney Meenakshi; Kaur Jatinder; Ralhan Ranju

    2010-01-01

    Abstract Background We reported increased levels of Phosphatidyl Inositol synthase (PI synthase), (enzyme that catalyses phosphatidyl inositol (PI) synthesis-implicated in intracellular signaling and regulation of cell growth) in smokeless tobacco (ST) exposed oral cell cultures by differential display. This study determined the clinical significance of PI synthase overexpression in oral squamous cell carcinoma (OSCC) and premalignant lesions (leukoplakia), and identified the downstream signa...

  16. From Biogenesis to Overexpression of Membrane Proteins in Escherichia coli

    OpenAIRE

    Wagner, Samuel

    2008-01-01

    In both pro- and eukaryotes 20-30% of all genes encode alpha-helical transmembrane domain proteins, which act in various and often essential capacities. Notably, membrane proteins play key roles in disease and they constitute more than half of all known drug targets. The natural abundance of membrane proteins is in general too low to conveniently isolate sufficient material for functional and structural studies. Therefore, most membrane proteins have to be obtained through overexpression. Esc...

  17. Overexpression of Protochlorophyllide Oxidoreductase C Regulates Oxidative Stress in Arabidopsis

    OpenAIRE

    Pattanayak, Gopal K.; Tripathy, Baishnab C

    2011-01-01

    Light absorbed by colored intermediates of chlorophyll biosynthesis is not utilized in photosynthesis; instead, it is transferred to molecular oxygen, generating singlet oxygen ((1)O(2)). As there is no enzymatic detoxification mechanism available in plants to destroy (1)O(2), its generation should be minimized. We manipulated the concentration of a major chlorophyll biosynthetic intermediate i.e., protochlorophyllide in Arabidopsis by overexpressing the light-inducible protochlorophyllide ox...

  18. Overexpression of esterase D in kidney from trisomy 13 fetuses.

    OpenAIRE

    Loughna, S; P. Bennett; Gau, G; K. Nicolaides; Blunt, S; Moore, G

    1993-01-01

    Human trisomy 13 (Patau syndrome) occurs in approximately 1 in 5,000 live births. It is compatible with life, but prolonged survival is rare. Anomalies often involve the urogenital, cardiac, craniofacial, and central nervous systems. It is possible that these abnormalities may be due to the overexpression of developmentally important genes on chromosome 13. The expression of esterase D (localized to chromosome 13q14.11) has been investigated in both muscle and kidney from trisomy 13 fetuses a...

  19. DKC1 overexpression associated with prostate cancer progression

    OpenAIRE

    Sieron, P; Hader, C; Hatina, J; Engers, R; Wlazlinski, A; Müller, M.; Schulz, W A

    2009-01-01

    Background: Dyskerin encoded by the DKC1 gene is a predominantly nucleolar protein essential for the formation of pseudouridine in RNA and the telomerase RNA subunit hTR. Inherited mutations inactivating dyskerin cause dyskeratosis congenita, a syndrome with progeroid features characterised by skin defects and haematopoiesis failure, as well as cancer susceptibility. In this study, we report DKC1 overexpression in prostate cancers. Methods: Expression of DKC1 was measured by quantitative RT–P...

  20. Overexpression of the riboflavin biosynthetic pathway in Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Mattanovich Diethard

    2008-07-01

    Full Text Available Abstract Background High cell density cultures of Pichia pastoris grown on methanol tend to develop yellow colored supernatants, attributed to the release of free flavins. The potential of P. pastoris for flavin overproduction is therefore given, but not pronounced when the yeast is grown on glucose. The aim of this study is to characterize the relative regulatory impact of each riboflavin synthesis gene. Deeper insight into pathway control and the potential of deregulation is established by overexpression of the single genes as well as a combined deregulation of up to all six riboflavin synthesis genes. Results Overexpression of the first gene of the riboflavin biosynthetic pathway (RIB1 is already sufficient to obtain yellow colonies and the accumulation of riboflavin in the supernatant of shake flask cultures growing on glucose. Sequential deregulation of all the genes, by exchange of their native promoter with the strong and constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (PGAP increases the riboflavin accumulation significantly. Conclusion The regulation of the pathway is distributed over more than one gene. High cell density cultivations of a P. pastoris strain overexpressing all six RIB genes allow the accumulation of 175 mg/L riboflavin in the supernatant. The basis for rational engineering of riboflavin production in P. pastoris has thus been established.

  1. Role of overexpressed CFA/I fimbriae in bacterial swimming

    International Nuclear Information System (INIS)

    Enterotoxigenic Escherichia coli CFA/I is a protective antigen and has been overexpressed in bacterial vectors, such as Salmonella Typhimurium H683, to generate vaccines. Effects that overexpressed CFA/I may engender on the bacterial host remain largely unexplored. To investigate, we constructed a high CFA/I expression strain, H683-pC2, and compared it to a low CFA/I expression strain, H683-pC, and to a non-CFA/I expression strain, H683-pY. The results showed that H683-pC2 was less able to migrate into semisolid agar (0.35%) than either H683-pC or H683-pY. Bacteria that migrated showed motility halo sizes of H683-pC2 < H683-pC < H683-pY. In the liquid culture media, H683-pC2 cells precipitated to the bottom of the tube, while those of H683-pY did not. In situ imaging revealed that H683-pC2 bacilli tended to auto-agglutinate within the semisolid agar, while H683-pY bacilli did not. When the cfaBE fimbrial fiber encoding genes were deleted from pC2, the new plasmid, pC2(-), significantly recovered bacterial swimming capability. Our study highlights the negative impact of overexpressed CFA/I fimbriae on bacterial swimming motility. (paper)

  2. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker)*

    Science.gov (United States)

    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 (P0.05), but the activities were significantly lower than the normal level at 4/5LT50 and LT50 (P<0.05). PMID:23024046

  3. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker).

    Science.gov (United States)

    Chen, Shi-chao; Liu, Xiao-qing; Jiang, Wen; Li, Ke-feng; Du, Jun; Shen, Dan-zhou; Gong, Quan

    2012-10-01

    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 (LC(50)) and the median lethal time (LT(50)) were determined to evaluate acute lethal effects on Chinese suckers. The results showed that the LC(50) values of 4, 6, 8, and 10 h were 142%, 137%, 135%, and 130%, respectively. The LT(50) 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 LT(50). 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 3/5LT(50) (P0.05), but the activities were significantly lower than the normal level at 4/5LT(50) and LT(50) (P<0.05). PMID:23024046

  4. Evaluation of Both Malondialdehyde and Catalase Enzymes In Semen, Tissue And Blood In Adult Men With Grade 3 Varicocele

    Directory of Open Access Journals (Sweden)

    Ercan Malkoc

    2013-04-01

    Full Text Available This work aimed to assess malondialdehyde (MDA and catalase (CAT levels in semen, blood and tissue and to investigate their relationship with spermiogram parameters in the presence of grade 3 varicocele patients. Following the partial removal of the varicose vein during varicocelectomy, both MDA and CAT levels were assessed in the tissue and semen fluid. Additionally MDA levels were measured in blood samples collected from varicose veins during varicocelectomy. A total of 88 patients, mean age 21.8, were enrolled in the study. While progressive motility (A + B was <32% in 11 (12.5%, and #8805; 32 in 77 (87.5% patients; the total motility (A + B + C was <40 in 11 (12.5%, and and #8805; 40% in 77 (87.5% patients. Sperm count was <5 million/ml in 13 patients (14.8%, <15million/ml in 29 (32.9%, and and #8805; 15million/ml in 40 (45.5% patients. When patients were subgrouped according to the spermia, sperm count and sperm motility ratios, MDA and CAT levels did not differ significantly except for semen MDA activity which was significantly higher in patients with a sperm count lower than 15 million per ml (p=0.044. This finding suggests that MDA levels may affect the sperm counts. [Dis Mol Med 2013; 1(2.000: 26-30

  5. Physiological analyses indicate superoxide dismutase, catalase, and phytochelatins play important roles in Pb tolerance in Eremochloa ophiuroides.

    Science.gov (United States)

    Li, Xi; Cen, Huameng; Chen, Youxiang; Xu, Siying; Peng, Lingli; Zhu, Hanmingyue; Li, Yiqiao

    2016-01-01

    Phytoremediation is considered to be a promising approach to restore or stabilize soil contaminated by lead (Pb). Turfgrasses, due to their high biomass yields, are considered to be suitable for use in phytoextraction of soil contaminated with heavy metal. It has been demonstrated that centipedegrass (Eremochloa ophiuroides (Munro) Hack., Poaceae) is a good turfgrass for restore of soil contaminated by Pb. However, the enhanced tolerant mechanisms in metallicolous (M) centipedegrass accessions remain unknown. In this study, we made a comparative study of growth performance, Pb accumulation, antioxidant levels, and phytochelatin concentrations in roots and shoots from M and nonmetallicolous (NM) centipedegrass accessions. Results showed that turf quality and growth rate were less repressed in M accessions than in NM accession. Pb stress caused generation of reactive oxygen species in centipedegrass with relatively lower levels in M accessions. Antioxidant activity analysis indicated that superoxide dismutase and catalase played important roles in Pb tolerance in M accessions. M accessions accumulated more Pb in roots and shoots. Greatly increased phytochelatins and less repressed sulfur contents in roots and shoots of M accessions indicated that they correlated with Pb accumulation and tolerance in centipedegrass. PMID:26368658

  6. Determination of oxidative stress in vitiligo by measuring superoxide dismutase and catalase levels in vitiliginous and non-vitiliginous skin

    Directory of Open Access Journals (Sweden)

    Sravani P

    2009-01-01

    Full Text Available Background: Vitiligo is an acquired disorder characterized by circumscribed depigmented macules devoid of identifiable melanocytes. Complex genetic, immunological, neural and self destructive mechanisms interplay in its pathogenesis. According to autocytotoxic hypothesis, oxidative stress has been suggested to be the initial pathogenic event in melanocyte degeneration. Aims: The aim of our investigation was to evaluate the role of oxidative stress by measuring levels of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT in lesional and normal skin of patients with vitiligo and in the skin of normal controls. Methods: We determined the activity of SOD in lesional and non-lesional skin and CAT in lesional skin only of 25 vitiligo patients and 25 controls by using the spectrophotometric assay and Aebi′s method, respectively. Results: There was statistically significant increase in the levels of SOD in vitiliginous and non vitiliginous skin of patient group compared to the control group ( P < 0.001. No significant difference was found between the levels of SOD in lesional skin and non-lesional skin of vitiligo patients. The levels of CAT in the skin of patients were found to be significantly lower than those of controls ( P < 0.001. Conclusions: There is increased oxidative stress in vitiligo as is indicated by high levels of SOD and low levels of CAT in the skin of vitiligo patients.

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

    Institute of Scientific and Technical Information of China (English)

    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 why such differences occur, the effects of simulated acid rain (pH 2.5-5.0) on the activities of peroxidase (ROD) and catalase (CAT) during seed ger-mination of rice (O. sativa),-wheat (T. aestivum), and rape (B. chinensis var. oleifera) were investigated. Results indi-cated that the maximum change in activities of CAT and POD by acid rain treatment with different acidity and time in relation to the referent treatment without acid rain, was in the order: rice (28.8%, 31.7%)wheat (4.0)>rape (5.0). Moreover, the change in activity of POD was higher than that of CAT, which showed that POD was more sensitive to acid rain stress than CAT. The difference in the ability of POD and CAT in removing free radicals was one reason why the germina-tion indexes of these three species behaved differently.

  8. Investigation on the interaction between isorhamnetin and bovine liver catalase by spectroscopic techniques under different pH conditions.

    Science.gov (United States)

    Yang, Yumin; Li, Daojin

    2016-08-01

    The binding of isorhamnetin to bovine liver catalase (BLC) was first investigated at 302, 310 and 318 K at pH 7.4 using spectroscopic methods including fluorescence spectra, circular dichroism (CD) and UV-vis absorption. Spectrophotometric observations are rationalized mainly in terms of a static quenching process. The binding constants and binding sites were evaluated by fluorescence quenching methods. Enzymatic activity of BLC in the absence and presence of isorhamnetin was measured using a UV/vis spectrophotometer. The result revealed that the binding of isorhamnetin to BLC led to a reduction in the activity of BLC. The positive entropy change and enthalpy change indicated that the interaction of isorhamnetin with BLC was mainly driven by hydrophobic forces. The distance r between the donor (BLC) and acceptor (isorhamnetin) was estimated to be 2.99 nm according to fluorescence resonance energy transfer. Fluorescence, synchronous fluorescence, and CD spectra showed no obvious change in the conformation of BLC upon the binding of isorhamnetin. In addition, the influence of pH on the binding of isorhamnetin to BLC was investigated and the binding ability of the drug to BLC deceased under other pH conditions (pH 9.0, 6.5, 5.0, 3.5, or 2.0) as compared with that at pH 7.4. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26748824

  9. Moonlighting of Helicobacter pylori catalase protects against complement-mediated killing by utilising the host molecule vitronectin

    Science.gov (United States)

    Richter, Corinna; Mukherjee, Oindrilla; Ermert, David; Singh, Birendra; Su, Yu-Ching; Agarwal, Vaibhav; Blom, Anna M.; Riesbeck, Kristian

    2016-01-01

    Helicobacter pylori is an important human pathogen and a common cause of peptic ulcers and gastric cancer. Despite H. pylori provoking strong innate and adaptive immune responses, the bacterium is able to successfully establish long-term infections. Vitronectin (Vn), a component of both the extracellular matrix and plasma, is involved in many physiological processes, including regulation of the complement system. The aim of this study was to define a receptor in H. pylori that binds Vn and determine the significance of the interaction for virulence. Surprisingly, by using proteomics, we found that the hydrogen peroxide-neutralizing enzyme catalase KatA is a major Vn-binding protein. Deletion of the katA gene in three different strains resulted in impaired binding of Vn. Recombinant KatA was generated and shown to bind with high affinity to a region between heparin-binding domain 2 and 3 of Vn that differs from previously characterised bacterial binding sites on the molecule. In terms of function, KatA protected H. pylori from complement-mediated killing in a Vn-dependent manner. Taken together, the virulence factor KatA is a Vn-binding protein that moonlights on the surface of H. pylori to promote bacterial evasion of host innate immunity. PMID:27087644

  10. Ultrasensitive fluorescence immunoassay for detection of ochratoxin A using catalase-mediated fluorescence quenching of CdTe QDs.

    Science.gov (United States)

    Huang, Xiaolin; Zhan, Shengnan; Xu, Hengyi; Meng, Xianwei; Xiong, Yonghua; Chen, Xiaoyuan

    2016-04-28

    Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to perform a dynamic linear detection of OTA ranging from 0.05 pg mL(-1) to 10 pg mL(-1). The half maximal inhibitory concentration was 0.53 pg mL(-1) and the limit of detection was 0.05 pg mL(-1). These values were approximately 283- and 300-folds lower than those of horseradish peroxidase (HRP)-based conventional ELISA, respectively. The reported method is accurate, highly reproducible, and specific against other mycotoxins in agricultural products as well. In summary, the developed fluorescence immunoassay based on H2O2-induced fluorescence quenching of CdTe QDs can be used for the rapid and highly sensitive detection of mycotoxins or haptens in food safety monitoring. PMID:27093176

  11. Evaluation of the serum catalase and myeloperoxidase activities in chronic arsenic-exposed individuals and concomitant cytogenetic damage

    International Nuclear Information System (INIS)

    Chronic arsenic exposure through contaminated drinking water is a major environmental health issue. Chronic arsenic exposure is known to exert its toxic effects by a variety of mechanisms, of which generation of reactive oxygen species (ROS) is one of the most important. A high level of ROS, in turn, leads to DNA damage that might ultimately culminate in cancer. In order to keep the level of ROS in balance, an array of enzymes is present, of which catalase (CAT) and myeloperoxidase (MPO) are important members. Hence, in this study, we determined the activities of these two enzymes in the sera and chromosomal aberrations (CA) in peripheral blood lymphocytes in individuals exposed and unexposed to arsenic in drinking water. Arsenic in drinking water and in urine was used as a measure of exposure. Our results show that individuals chronically exposed to arsenic have significantly higher CAT and MPO activities and higher incidence of CA. We found moderate positive correlations between CAT and MPO activities, induction of CA and arsenic in urine and water. These results indicate that chronic arsenic exposure causes higher CAT and MPO activities in serum that correlates with induction of genetic damage. We conclude that the serum levels of these enzymes might be used as biomarkers of early arsenic exposure induced disease much before the classical dermatological symptoms of arsenicosis begin to appear.

  12. The effect of seedling chilling on glutathione content, catalase and peroxidase activity in Brassica oleracea L. var. italica

    Directory of Open Access Journals (Sweden)

    Renata Wojciechowska

    2013-09-01

    Full Text Available The study was designed to determine the possible relationship between Brassica oleracea var. italica seedlings stored at 2°C in the dark for seven and fourteen days, respectively, and the level of certain antioxidant parameters in particular organs. A parallel objective of the experiment was to determine if the reaction of seedlings to low temperature might be persistent in fully developed plants until harvest time. After 14 days of chilling a significant increase in the glutathione content was observed in the seedling leaves in comparison to the non-chilled plants. During vegetation in field conditions this effect was maintained in leaves up to the stage of formation of flower buds. At harvest the highest content of glutathione was demonstrated in broccoli heads, obtained from plants, which were previously chilled in the seedling phase for two weeks. Peroxidase activity in broccoli seedlings increased each year of the three-year study due to the duration of the cooling time, whereas in the case of catalase the changes were not so distinct. At harvest time the activity of both enzymes in the leaves and flower buds fluctuated according to the particular year of study.

  13. Transcriptional and epigenetic regulation of KIF14 overexpression in ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Brigitte L Thériault

    Full Text Available KIF14 (kinesin family member 14 is a mitotic kinesin and an important oncogene in several cancers. Tumor KIF14 expression levels are independently predictive of poor outcome, and in cancer cells KIF14 can modulate metastatic behavior by maintaining appropriate levels of cell adhesion and migration proteins at the cell membrane. Thus KIF14 is an exciting potential therapeutic target. Understanding KIF14's regulation in cancer cells is crucial to the development of effective and selective therapies to block its tumorigenic function(s. We previously determined that close to 30% of serous ovarian cancers (OvCa tumors exhibit low-level genomic gain, indicating one mechanism of KIF14 overexpression in tumors. We now report on transcriptional and epigenetic regulation of KIF14. Through promoter deletion analyses, we identified one cis-regulatory region containing binding sites for Sp1, HSF1 and YY1. siRNA-mediated knockdown of these transcription factors demonstrated endogenous regulation of KIF14 overexpression by Sp1 and YY1, but not HSF1. ChIP experiments confirmed an enrichment of both Sp1 and YY1 binding to the endogenous KIF14 promoter in OvCa cell lines with high KIF14 expression. A strong correlation was seen in primary serous OvCa tumors between Sp1, YY1 and KIF14 expression, further evidence that these transcription factors are important players in KIF14 overexpression. Hypomethylation patterns were observed in primary serous OvCa tumors, suggesting a minor role for promoter methylation in the control of KIF14 gene expression. miRNA expression analysis determined that miR-93, miR-144 and miR-382 had significantly lower levels of expression in primary serous OvCa tumors than normal tissues; treatment of an OvCa cell line with miRNA mimics and inhibitors specifically modulated KIF14 mRNA levels, pointing to potential novel mechanisms of KIF14 overexpression in primary tumors. Our findings reveal multiple mechanisms of KIF14 upregulation in

  14. Overexpression of Mineralocorticoid Receptors Partially Prevents Chronic Stress-Induced Reductions in Hippocampal Memory and Structural Plasticity.

    Directory of Open Access Journals (Sweden)

    Sofia Kanatsou

    Full Text Available Exposure to chronic stress is a risk factor for cognitive decline and psychopathology in genetically predisposed individuals. Preliminary evidence in humans suggests that mineralocorticoid receptors (MRs may confer resilience to these stress-related changes. We specifically tested this idea using a well-controlled mouse model for chronic stress in combination with transgenic MR overexpression in the forebrain. Exposure to unpredictable stressors for 21 days in adulthood reduced learning and memory formation in a low arousing hippocampus-dependent contextual learning task, but enhanced stressful contextual fear learning. We found support for a moderating effect of MR background on chronic stress only for contextual memory formation under low arousing conditions. In an attempt to understand potentially contributing factors, we studied structural plasticity. Chronic stress altered dendritic morphology in the hippocampal CA3 area and reduced the total number of doublecortin-positive immature neurons in the infrapyramidal blade of the dentate gyrus. The latter reduction was absent in MR overexpressing mice. We therefore provide partial support for the idea that overexpression of MRs may confer resilience to the effects of chronic stress on hippocampus-dependent function and structural plasticity.

  15. Overexpression of brain-derived neurotrophic factor in the hippocampus protects against post-stroke depression

    Institute of Scientific and Technical Information of China (English)

    Hao-hao Chen; Ning Zhang; Wei-yun Li; Ma-rong Fang; Hui Zhang; Yuan-shu Fang; Ming-xing Ding; Xiao-yan Fu

    2015-01-01

    Post-stroke depression is associated with reduced expression of brain-derived neurotrophic factor (BDNF). In this study, we evaluated whether BDNF overexpression affects depression-like behavior in a rat model of post-stroke depression. The middle cerebral artery was occluded to produce a model of focal cerebral ischemia. These rats were then subjected to isolation-housing combined with chronic unpredictable mild stress to generate a model of post-stroke depression. ABDNF gene lentiviral vector was injected into the hippocampus. At 7 days after injection, western blot assay and real-time quantitative PCR revealed that BDNF expression in the hippo-campus was increased in depressive rats injected with BDNF lentivirus compared with depressive rats injected with control vector. Furthermore, sucrose solution consumption was higher, and horizontal and vertical movement scores were increased in the open ifeld test in these rats as well. These ifndings suggest that BDNF overexpression in the hippocampus of post-stroke depressive rats alleviates depression-like behaviors.

  16. Levetiracetam reverses synaptic deficits produced by overexpression of SV2A.

    Directory of Open Access Journals (Sweden)

    Amy Nowack

    Full Text Available Levetiracetam is an FDA-approved drug used to treat epilepsy and other disorders of the nervous system. Although it is known that levetiracetam binds the synaptic vesicle protein SV2A, how drug binding affects synaptic functioning remains unknown. Here we report that levetiracetam reverses the effects of excess SV2A in autaptic hippocampal neurons. Expression of an SV2A-EGFP fusion protein produced a ∼1.5-fold increase in synaptic levels of SV2, and resulted in reduced synaptic release probability. The overexpression phenotype parallels that seen in neurons from SV2 knockout mice, which experience severe seizures. Overexpression of SV2A also increased synaptic levels of the calcium-sensor protein synaptotagmin, an SV2-binding protein whose stability and trafficking are regulated by SV2. Treatment with levetiracetam rescued normal neurotransmission and restored normal levels of SV2 and synaptotagmin at the synapse. These results indicate that changes in SV2 expression in either direction impact neurotransmission, and suggest that levetiracetam may modulate SV2 protein interactions.

  17. Perfil de susceptibilidade a antimicrobianos em amostras de cocos Gram-positivos, catalase negativos, isoladas de mastite subclínica bubalina Profile of antimicrobial susceptibility in strains of Gram positive cocos, negative catalase, isolated from buffalo subclinical mastitis

    Directory of Open Access Journals (Sweden)

    Maria C.E. Vianni

    2003-06-01

    Full Text Available Estudou-se o perfil de susceptibilidade a antimicrobianos em cocos Gram-positivos catalase negativos (21 amostras de Lactococcus garvieae e 6 de Enterococcus gallinarum, isoladas do leite de fêmeas com mastite subclínica e pertencentes a uma população composta por seis rebanhos bubalinos localizados no Estado do Rio de Janeiro. O teste utilizado foi o da difusão de discos em agar Müller Hinton, segundo recomendações do National Committee for Clinical Laboratory Standards - NCCLS, tendo sido testados discos com ampicilina (10mg, cefalotina (30mg, cefotaxima (30mg, cefoxitina (30mg, cloranfenicol (30mg, eritromicina (15mg, gentamicina (10mg, nitrofurantoína (300mg, norfloxacina (10mg, penicilina (10 UI, tetraciclina (30mg e vancomicina (30mg. Os resultados evidenciaram que em se tratando de Lactococcus garvieae, o antimicrobiano mais eficiente foi o nitrofurantoína com 85,71% de sensibilidade, seguido da cefotaxima (61,90%, vancomicina (52,38%, norfloxacina (47,62% e cefalotina (47,62%. A maior resistência foi desenvolvida frente a penicilina e ampicilina, com 95,24% de resistênciapara os dois antimicrobianos testados. O perfil de susceptibilidade desenvolvido pelas amostras de Enterococcus gallinarum, mostrou baixa sensibilidade frente aos antimicrobianos testados, onde os maiores índices foram observados frente eritromicina e gentamicina, com 33,34% de sensibilidade para ambos; quanto à resistência desenvolvida, foi possível observar 100% de resistência com relação a vancomicina e tetraciclina, seguindo-se cloranfenicol, penicilina, ampicilina, cefoxitina, cefalotina, cefotaxima, norfloxacina e nitrofurantoína, todas evidenciando uma resistência de 83,33% das amostras testadas.The susceptibility of antimicrobials was studied in Gram positive and catalase negative cocci (21 samples of Lactococcus garvieae and 6 Enterococcus gallinarum, isolated from the milk of cows with subclinical mastitis, belonging to six buffalo herds in

  18. Identification and Overexpression of a Knotted1-Like Transcription Factor in Switchgrass (Panicum virgatum L.) for Lignocellulosic Feedstock Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Wuddineh, Wegi A.; Mazarei, Mitra; Zhang, Ji-Yi; Turner, Geoffrey B.; Sykes, Robert W.; Decker, Stephen R.; Davis, Mark F.; Udvardi, Michael K.; Stewart, C. Neal, Jr.

    2016-04-28

    High biomass production and wide adaptation has made switchgrass (Panicum virgatum L.) an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Gene expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox) gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox) genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signaling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our results demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.

  19. Identification and overexpression of a Knotted1-like transcription factor in switchgrass (Panicum virgatum L. for lignocellulosic feedstock improvement

    Directory of Open Access Journals (Sweden)

    Wegi eWuddineh

    2016-04-01

    Full Text Available High biomass production and wide adaptation has made switchgrass (Panicum virgatum L. an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Gene expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signalling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our results demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.

  20. Ultrasensitive fluorescence immunoassay for detection of ochratoxin A using catalase-mediated fluorescence quenching of CdTe QDs

    Science.gov (United States)

    Huang, Xiaolin; Zhan, Shengnan; Xu, Hengyi; Meng, Xianwei; Xiong, Yonghua; Chen, Xiaoyuan

    2016-04-01

    Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to perform a dynamic linear detection of OTA ranging from 0.05 pg mL-1 to 10 pg mL-1. The half maximal inhibitory concentration was 0.53 pg mL-1 and the limit of detection was 0.05 pg mL-1. These values were approximately 283- and 300-folds lower than those of horseradish peroxidase (HRP)-based conventional ELISA, respectively. The reported method is accurate, highly reproducible, and specific against other mycotoxins in agricultural products as well. In summary, the developed fluorescence immunoassay based on H2O2-induced fluorescence quenching of CdTe QDs can be used for the rapid and highly sensitive detection of mycotoxins or haptens in food safety monitoring.Herein, for the first time we report an improved competitive fluorescent enzyme linked immunosorbent assay (ELISA) for the ultrasensitive detection of ochratoxin A (OTA) by using hydrogen peroxide (H2O2)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (QDs). In this immunoassay, catalase (CAT) was labeled with OTA as a competitive antigen to connect the fluorescence signals of the QDs with the concentration of the target. Through the combinatorial use of H2O2-induced fluorescence quenching of CdTe QDs as a fluorescence signal output and the ultrahigh catalytic activity of CAT to H2O2, our proposed method could be used to

  1. Effects of total dissolved gas supersaturated water on lethality and catalase activity of Chinese sucker (Myxocyprinus asiaticus Bleeker)

    Institute of Scientific and Technical Information of China (English)

    Shi-chao CHEN; Xiao-qing LIU; Wen JIANG; Ke-feng LI; Jun DU; Dan-zhou SHEN; Quan GONG

    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).

  2. Electrospun Poly(acrylonitrile-co-acrylic acid) Nanofibrous Membranes for Catalase Immobilization:Effect of Porphyrin Filling on the Enzyme Activity

    Institute of Scientific and Technical Information of China (English)

    KE Bei-bei; WAN Ling-shu; HUANG Xiao-jun; XU Zhi-kang

    2011-01-01

    Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acryionitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenyiporphyrin(TPP) and its metalloderivatives(ZnTPP and CuTPP) were studied as filling mediators for the immobilization of redox enzyme. Results indicate that the introduction of TPP, ZnTPP and CuTPP improves the retention activity of the immobilized catalase.Among these three porphyrins, the ZnTPP-filled PANCAA nanofibrous membrane exhibits an activity retention of 93%, which is an exciting improvement. This improvement is attributed to both the strong catalase-porphyrin affinity and the possible facilitated electron transfer induced by the porphyrin as evidenced by quartz crystal microbalance (QCM) and fluorescence spectroscopy studies.

  3. Catalase immobilized on a functionalized multi-walled carbon nanotubes–gold nanocomposite as a highly sensitive bio-sensing system for detection of hydrogen peroxide

    International Nuclear Information System (INIS)

    By immobilizing catalase on a nanocomposite containing functionalized multi-walled carbon nanotubes and L-cysteine modified gold nanoparticles, a third generation biosensor was developed for determination of the hydrogen peroxide. The cyclic voltammograms of catalase on the nanocomposite modified glassy carbon electrode showed a pair of well-defined quasi-reversible redox peaks with the formal potential of −441 ± 2 mV versus Ag/AgCl at a scan rate of 0.05 V/s. The heterogeneous electron transfer constant was calculated to be 8.72 s−1. The enzyme electrode response toward hydrogen peroxide was linear in the concentrations ranging from 1 nM to 1 μM, with a detection limit of 0.5 nM. The apparent Michaelis–Menten constant was calculated to be 0.34 μM

  4. L’INFLUENCE DE L’HERBICIDE GRAMOXONE SUR L’ACTIVITÉ DE LA CATALASE DANS LES GRAINS DE BLÉ ET DE HARICOT AU COURS DE LA GERMINATION

    OpenAIRE

    Anca Huma; Antoanela Patras; Vlad Artenie; Paula Amagdei

    2003-01-01

    Cet ouvrage présente l’étude de l’influence de l’herbicide Gramoxone dont la substance active est le paraquat (méthy le viologène) sur l’activité de la catalase (EC. 1.11.1.6) dans les grains de blé (Triticum aestivum) et d’haricot au cours de la germination. L’activité de la catalase dans les grains germinés des deux espèces des plantes est inhibée par toutes les concentrations de Gramoxone testées. L’effet inhibiteur de celui-ci s’accentue avec l’augmentation de sa concentration, e...

  5. Change in the Content of Salicylic Acid and in the Activities of Phenylalanine Ammonia-Lyase and Catalase in Wheat Seedling Roots Under the Effect of Azospirillum Lectins

    Directory of Open Access Journals (Sweden)

    Alen'kina S.A.

    2012-05-01

    Full Text Available We investigated the time course of changes in the endogenous content of salicylic acid, the ratio between the acid's free and bound forms, and changes in the activities of phenylalanine ammonia-lyase and catalase in wheat seedling roots under the effect of the lectins of two strains of the associative nitrogen-fixing bacterium Azospirillum: A. brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3. Differences in plant response to the action of the lectins from these two strains were established. On the basis of the obtained data, a model was proposed for lectin-assisted induction of resistance, according to which the lectin effect on the roots of seedlings results in accumulation of free salicylic acid, which inhibits catalase activity, ultimately leading to accumulation of hydrogen peroxide and to formation of induced resistance.

  6. Properties of astrocytes cultured from GFAP over-expressing and GFAP mutant mice

    International Nuclear Information System (INIS)

    Alexander disease is a fatal leukoencephalopathy caused by dominantly-acting coding mutations in GFAP. Previous work has also implicated elevations in absolute levels of GFAP as central to the pathogenesis of the disease. However, identification of the critical astrocyte functions that are compromised by mis-expression of GFAP has not yet been possible. To provide new tools for investigating the nature of astrocyte dysfunction in Alexander disease, we have established primary astrocyte cultures from two mouse models of Alexander disease, a transgenic that over-expresses wild type human GFAP, and a knock-in at the endogenous mouse locus that mimics a common Alexander disease mutation. We find that mutant GFAP, as well as excess wild type GFAP, promotes formation of cytoplasmic inclusions, disrupts the cytoskeleton, decreases cell proliferation, increases cell death, reduces proteasomal function, and compromises astrocyte resistance to stress.

  7. Properties of astrocytes cultured from GFAP over-expressing and GFAP mutant mice

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Woosung [Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, 1500 Highland Ave, Rm 713, Madison, WI 53705 (United States); Messing, Albee, E-mail: messing@waisman.wisc.edu [Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, 1500 Highland Ave, Rm 713, Madison, WI 53705 (United States)

    2009-04-15

    Alexander disease is a fatal leukoencephalopathy caused by dominantly-acting coding mutations in GFAP. Previous work has also implicated elevations in absolute levels of GFAP as central to the pathogenesis of the disease. However, identification of the critical astrocyte functions that are compromised by mis-expression of GFAP has not yet been possible. To provide new tools for investigating the nature of astrocyte dysfunction in Alexander disease, we have established primary astrocyte cultures from two mouse models of Alexander disease, a transgenic that over-expresses wild type human GFAP, and a knock-in at the endogenous mouse locus that mimics a common Alexander disease mutation. We find that mutant GFAP, as well as excess wild type GFAP, promotes formation of cytoplasmic inclusions, disrupts the cytoskeleton, decreases cell proliferation, increases cell death, reduces proteasomal function, and compromises astrocyte resistance to stress.

  8. Hepatic steatosis in transgenic mice overexpressing human histone deacetylase 1

    International Nuclear Information System (INIS)

    It is generally thought that histone deacetylases (HDACs) play important roles in the transcriptional regulation of genes. However, little information is available concerning the specific functions of individual HDACs in disease states. In this study, two transgenic mice lines were established which harbored the human HDAC1 gene. Overexpressed HDAC1 was detected in the nuclei of transgenic liver cells, and HDAC1 enzymatic activity was significantly higher in the transgenic mice than in control littermates. The HDAC1 transgenic mice exhibited a high incidence of hepatic steatosis and nuclear pleomorphism. Molecular studies showed that HDAC1 may contribute to nuclear pleomorphism through the p53/p21 signaling pathway

  9. Formation of chloroplast protrusions and catalase activity in alpine Ranunculus glacialis under elevated temperature and different CO2/O2 ratios

    OpenAIRE

    Buchner, Othmar; Moser, Tim; Karadar, Matthias; Roach, Thomas; Kranner, Ilse; Holzinger, Andreas

    2015-01-01

    Chloroplast protrusions (CPs) have frequently been observed in plants, but their significance to plant metabolism remains largely unknown. We investigated in the alpine plant Ranunculus glacialis L. treated under various CO2 concentrations if CP formation is related to photorespiration, specifically focusing on hydrogen peroxide (H2O2) metabolism. Immediately after exposure to different CO2 concentrations, the formation of CPs in leaf mesophyll cells was assessed and correlated to catalase (C...

  10. Effect of Orange (Citrus sinensis) Peel Oil on Lipid Peroxidation, Catalase activity and Hepatic Biomarker levels in Blood Plasma of Normo Rats

    OpenAIRE

    Erukainure, Ochuko L.

    2012-01-01

    Dietary antioxidants are considered beneficial because of their potential protective role against oxidative stress, which is involved in the pathogenesis of multiple diseases such as cancer and coronary heart disease. The effect of feeding orange peel oil on lipid peroxidation, catalase and hepatic biomarkers in blood plasma of normo rats was investigated. Beside mouse chow, four diets were designed to contain 50% of energy as carbohydrate, 35% as fat, and 15% as protein, and one that was lip...

  11. The Therapeutic Effects of a Medicinal Plant Mixture in Capsule Form on Catalase Levels in the Semen of Men with Oligospermia

    OpenAIRE

    Alizadeh Hasti; Khaki Arash; Farzadi Laya; Nouri Mohammad; Ahmadi-Asrbadr Yadoulah; Seyed-Ghiasi Giti; Shahnazi Vahideh

    2015-01-01

    Objective: In the present study, the therapeutic effects of mixed herbs (onion, ginger, basil, cinnamon, orange peel, yellow and red watermelon seeds, and carrot seed) on catalase levels in the semen of men with oligospermia were evaluated. About 50% of recognized infertility factors are male-related factors, and are mainly the result of oligospermia, astenospermia, and teratozoospermia. Materials and Methods: The study participants included 40 males with o...

  12. Cytoplasmic expression of recombinant interleukin-2 and interleukin-4 proteins results in hydrogen peroxide accumulation and reduction in catalase activity in Escherichia coli

    OpenAIRE

    M.S Hejazi; F Karimi; E Mehdizadeh Aghdam; Barzegari, A. (MSc); M Farshdosti Hagh; Parvizi, M.; L Mahmoodi Azar; Hejazi, M. A.

    2009-01-01

    Background and the purpose of the study: The Reactive oxygen species (ROS) is induced in the cells following various stresses but the effect of recombinant protein expression on ROS generation has not been studied yet. In this study, H2O2 concentration and catalase activity variations and their correlation with cell growth following cytoplasmic expression of human interleukin-2 (hIL-2) and mouse interleukin-4 (mIL-4) in Escherichia coli were investigated. Additionally, the effect of recombina...

  13. Influence of Foreign DNA Introduction and Periplasmic Expression of Recombinant Human Interleukin-2 on Hydrogen Peroxide Quantity and Catalase Activity in Escherichia coli

    OpenAIRE

    Lena Mahmoudi Azar; Elnaz Mehdizadeh Aghdam; Farrokh Karimi; Babak Haghshenas; Abolfazl Barzegari; Parichehr Yaghmaei; Mohammad Saeid Hejazi

    2013-01-01

    Purpose: Oxidative stress is generated through imbalance between composing and decomposing of reactive oxygen species (ROS). This kind of stress was rarely discussed in connection with foreign protein production in Escherichia coli. Effect of cytoplasmic recombinant protein expression on Hydrogen peroxide concentration and catalase activity was previously reported. In comparison with cytoplasm, periplasmic space has different oxidative environment. Therefore, in present study we describe t...

  14. Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.

    Science.gov (United States)

    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 (1870 bp) 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 0.5 days 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

  15. The Therapeutic Effects of a Medicinal Plant Mixture in Capsule Form on Catalase Levels in the Semen of Men with Oligospermia

    Directory of Open Access Journals (Sweden)

    Alizadeh Hasti

    2015-01-01

    Full Text Available Objective: In the present study, the therapeutic effects of mixed herbs (onion, ginger, basil, cinnamon, orange peel, yellow and red watermelon seeds, and carrot seed on catalase levels in the semen of men with oligospermia were evaluated. About 50% of recognized infertility factors are male-related factors, and are mainly the result of oligospermia, astenospermia, and teratozoospermia. Materials and Methods: The study participants included 40 males with oligospermia and infertility. The studied medicine were 700 mg capsules containing onion, ginger, basil, cinnamon, orange peel, yellow and red watermelon seeds, and carrot seed (100 mg of each. Catalase activity was measured by Aebi method. Results: A significant increase was observed in catalase level in semen as a result of using the medicinal plant mixture (P < 0.001. Conclusion: Free radicals play an important role in male infertility. Antioxidants can prevent the damaging effects they have on sperm. Oxidative stress reduction can increase the chances of natural fertility or assisted reproductive technology (ART. Medicinal plants have low costs, complications, and easy availability, and cause an increase in semen plasma antioxidants and subsequent improvement in semen parameters. Thus, they can be the source of new hopes for the treatment of infertility.

  16. Overexpression of ERβ is sufficient to inhibit hypoxia-inducible factor-1 transactivation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choa; Lee, YoungJoo, E-mail: yjlee@sejong.ac.kr

    2014-07-18

    Highlights: • We examined the effect of ERβ specific ligand on HIF-1 inhibition. • DPN down-regulates the ARNT protein levels in PC3 cells. • DPN did not show additional effect in ERβ transfected MCF-7 cells. • Our study shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression. - Abstract: Estrogen receptor (ER) β is predicted to play an important role in the prevention of breast cancer development and progression. We have previously shown that ERβ suppresses hypoxia inducible factor (HIF)-1-mediated transcription through aryl hydrocarbon receptor nuclear translocator (ARNT) degradation via ubiquitination processes. In this study, we attempted to examine the effect of ERβ specific ligand on HIF-1 inhibition in ERβ positive PC3 cells and ERβ transfected MCF-7 cells. ERβ specific agonist diarylpropionitrile (DPN) stimulated estrogen response element (ERE)-luciferase activity in a similar fashion to estradiol in PC3 cells. We observed that DPN down-regulates the ARNT protein levels leading to an attenuation of hypoxia-induced hypoxia response element (HRE)-driven luciferase reporter gene activation in PC3 cells. Treatment of DPN reduced vascular endothelial growth factor (VEGF) expression and co-treatment with ERβ specific antagonist PHTPP abrogated the effect in PC3 cells. We then examined the effect of DPN in ERβ transfected MCF-7 cells. HIF-1 transcriptional activity repression by ERβ was not further reduced by DPN, as examined by HRE-driven luciferase assays. Expression of ERβ significantly decreased VEGF secretion and ARNT expression under hypoxic conditions. However, DPN did not additionally affect this suppression in MCF-7 cells transfected with ERβ. This result shows that unliganded ERβ is sufficient to inhibit HIF-1 in systems of overexpression.

  17. Overexpression of fatty acid amide hydrolase induces early flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Neal D. Teaster

    2012-02-01

    Full Text Available N-Acylethanolamines (NAEs are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE. In animal systems this reaction is part of the endocannabinoid signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH, which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440 lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA, enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD and inductive long day (LD conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3, were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.

  18. The over-expression of cell migratory genes in alveolar rhabdomyosarcoma could contribute to metastatic spread.

    Science.gov (United States)

    Rapa, Elizabeth; Hill, Sophie K; Morten, Karl J; Potter, Michelle; Mitchell, Chris

    2012-06-01

    Alveolar (ARMS) and Embryonal (ERMS) rhabdomyosarcoma differ in their response to current treatments. The ARMS subtype has a less favourable prognosis and often presents with widespread metastases, while the less metastatic ERMS has a 5 year survival rate of more than 80 %. In this study we investigate gene expression differences that could contribute to the high frequency of metastasis in ARMS. Microarray analysis identified significant differences in DNA repair, cell cycle and cell migration between the two RMS subtypes. Two genes up regulated in ARMS and involved in cell migration; the engulfment and cell motility gene 1 (ELMO1) and NEL-like 1 gene (NELL1) were selected for further investigation. Over-expression of ELMO1 significantly increased cell invasion from 24.70 ± 7% to 93 ± 5.4% in primary myoblasts and from 29.43 ± 2.1% to 87.33 ± 4.1% in the ERMS cell line RD. siRNA knockout of ELMO1 in the ARMS cell line RH30 significantly reduced cell invasion from 88.2 ± 3.8% to 35.2 ± 2.5%. Over-expression of NELL1 significantly increased myoblast invasion from 23.6 ± 6.9% to 100 ± 0.1%, but had no effect on invasion of the ERMS cell line RD. These findings suggest that ELMO1 may play a key role in ARMS metastasis. NELL1 increased invasion in primary myoblasts, but other factors required for it to enhance motility were not present in the RD ERMS cell line. Impairing ELMO1 function by pharmacological or siRNA knockdown could be a highly effective approach to reduce the metastatic spread of RMS. PMID:22415709

  19. p8/TTDA overexpression enhances UV-irradiation resistance and suppresses TFIIH mutations in a Drosophila trichothiodystrophy model.

    Directory of Open Access Journals (Sweden)

    Javier Aguilar-Fuentes

    2008-11-01

    Full Text Available Mutations in certain subunits of the DNA repair/transcription factor complex TFIIH are linked to the human syndromes xeroderma pigmentosum (XP, Cockayne's syndrome (CS, and trichothiodystrophy (TTD. One of these subunits, p8/TTDA, interacts with p52 and XPD and is important in maintaining TFIIH stability. Drosophila mutants in the p52 (Dmp52 subunit exhibit phenotypic defects similar to those observed in TTD patients with defects in p8/TTDA and XPD, including reduced levels of TFIIH. Here, we demonstrate that several Dmp52 phenotypes, including lethality, developmental defects, and sterility, can be suppressed by p8/TTDA overexpression. TFIIH levels were also recovered in rescued flies. In addition, p8/TTDA overexpression suppressed a lethal allele of the Drosophila XPB homolog. Furthermore, transgenic flies overexpressing p8/TTDA were more resistant to UV irradiation than were wild-type flies, apparently because of enhanced efficiency of cyclobutane-pyrimidine-dimers and 6-4 pyrimidine-pyrimidone photoproducts repair. This study is the first using an intact higher-animal model to show that one subunit mutant can trans-complement another subunit in a multi-subunit complex linked to human diseases.

  20. Overexpression of MuHSP70 gene from Macrotyloma uniflorum confers multiple abiotic stress tolerance in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Masand, Shikha; Yadav, Sudesh Kumar

    2016-02-01

    A 70-KD heat shock protein (HSP70) is one of the most conserved chaperones. It is involved in de novo protein folding and prevents the aggregation of unfolded proteins under lethal environmental factors. The purpose of this study is to characterise a MuHSP70 from horsegram (Macrotyloma uniflorum) and elucidating its role in stress tolerance of plants. A MuHSP70 was cloned and characterised from a natural drought stress tolerant HPK4 variety of horsegram (M. uniflorum). For functional characterization, MuHSP70 was overexpressed in transgenic Arabidopsis. Overexpression of MuHSP70 was found to provide tolerance to the transgenic Arabidopsis against various stresses such as heat, cold, drought, salinity and oxidative stress. MuHSP70 transgenics were observed to maintain the shoot biomass, root length, relative water content, and chlorophyll content during exposure to multi-stresses relative to non-transgenic control. Transgenic lines have further shown the reduced levels of MDA, H2O2, and proteolytic activity. Together, these findings suggest that overexpression of MuHSP70 plays an important role in improving abiotic stress tolerance and could be a crucial candidate gene for exploration in crop improvement program. PMID:26694324

  1. Proinflammatory cytokine production and insulin sensitivity regulated by overexpression of resistin in 3T3-L1 adipocytes

    Directory of Open Access Journals (Sweden)

    Garvey W Timothy

    2006-07-01

    Full Text Available Abstract Resistin is secreted from adipocytes, and high circulating levels have been associated with obesity and insulin resistance. To investigate whether resistin could exert autocrine effects in adipocytes, we expressed resistin gene in 3T3-L1 fibroblasts using a lentiviral vector, and selected several stably-transduced cell lines under blasticidin selection. We observed that 3T3-L1 adipocytes expressing resistin have a decreased gene expression for related transcriptional factors (CCAAT/enhancer binding protein α(C/EBPα , peroxisome proliferator-activated receptor gamma (PPARγ, and adipocyte lipid binding protein (ALBP/aP2 which is one of target genes for the PPARγ during adipocyte differentiation,. Overexpression of resistin increased the levels of three proinflammatory cytokines, tumor necrosis factor alpha (TNFα, interleukin 6 (IL-6 and monocyte chemoattractant protein-1 (MCP-1, which play important roles for insulin resistance, glucose and lipid metabolisms during adipogenesis. Furthermore, overexpressing resistin in adipocytes inhibits glucose transport 4 (GLUT4 activity and its gene expression, reducing insulin's ability for glucose uptake by 30 %. In conclusion, resistin overexpression in stably transduced 3T3-L1 cells resulted in: 1 Attenuation of programmed gene expression responsible for adipogenesis; 2 Increase in expression of proinflammatory cytokines; 3 Decrease in insulin responsiveness of the glucose transport system. These data suggest a new role for resistin as an autocrine/paracrine factor affecting inflammation and insulin sensitivity in adipose tissue.

  2. Overexpression of Rad in muscle worsens diet-induced insulin resistance and glucose intolerance and lowers plasma triglyceride level

    Science.gov (United States)

    Ilany, Jacob; Bilan, Philip J.; Kapur, Sonia; Caldwell, James S.; Patti, Mary-Elizabeth; Marette, Andre; Kahn, C. Ronald

    2006-03-01

    Rad is a low molecular weight GTPase that is overexpressed in skeletal muscle of some patients with type 2 diabetes mellitus and/or obesity. Overexpression of Rad in adipocytes and muscle cells in culture results in diminished insulin-stimulated glucose uptake. To further elucidate the potential role of Rad in vivo, we have generated transgenic (tg) mice that overexpress Rad in muscle using the muscle creatine kinase (MCK) promoter-enhancer. Rad tg mice have a 6- to 12-fold increase in Rad expression in muscle as compared to wild-type littermates. Rad tg mice grow normally and have normal glucose tolerance and insulin sensitivity, but have reduced plasma triglyceride levels. On a high-fat diet, Rad tg mice develop more severe glucose intolerance than the wild-type mice; this is due to increased insulin resistance in muscle, as exemplified by a rightward shift in the dose-response curve for insulin stimulated 2-deoxyglucose uptake. There is also a unexpected further reduction of the plasma triglyceride levels that is associated with increased levels of lipoprotein lipase in the Rad tg mice. These results demonstrate a potential synergistic interaction between increased expression of Rad and high-fat diet in creation of insulin resistance and altered lipid metabolism present in type 2 diabetes. diabetes mellitus | glucose transport | RGK GTPase | transgenic mouse

  3. SNEV overexpression extends the life span of human endothelial cells

    International Nuclear Information System (INIS)

    In a recent screening for genes downregulated in replicatively senescent human umbilical vein endothelial cells (HUVECs), we have isolated the novel protein SNEV. Since then SNEV has proven as a multifaceted protein playing a role in pre-mRNA splicing, DNA repair, and the ubiquitin/proteosome system. Here, we report that SNEV mRNA decreases in various cell types during replicative senescence, and that it is increased in various immortalized cell lines, as well as in breast tumors, where SNEV transcript levels also correlate with the survival of breast cancer patients. Since these mRNA profiles suggested a role of SNEV in the regulation of cell proliferation, the effect of its overexpression was tested. Thereby, a significant extension of the cellular life span was observed, which was not caused by altered telomerase activity or telomere dynamics but rather by enhanced stress resistance. When SNEV overexpressing cells were treated with bleomycin or bleomycin combined with BSO, inducing DNA damage as well as reactive oxygen species, a significantly lower fraction of apoptotic cells was found in comparison to vector control cells. These data suggest that high levels of SNEV might extend the cellular life span by increasing the resistance to stress or by improving the DNA repair capacity of the cells

  4. Azotobacter vinelandii NADPH:ferredoxin reductase cloning, sequencing, and overexpression.

    Science.gov (United States)

    Isas, J M; Yannone, S M; Burgess, B K

    1995-09-01

    Azotobacter vinelandii ferredoxin I (AvFdI) controls the expression of another protein that was originally designated Protein X. Recently we reported that Protein X is a NADPH-specific flavoprotein that binds specifically to FdI (Isas, J.M., and Burgess, B.K. (1994) J. Biol. Chem. 269, 19404-19409). The gene encoding this protein has now been cloned and sequenced. Protein X is 33% identical and has an overall 53% similarity with the fpr gene product from Escherichia coli that encodes NADPH:ferredoxin reductase. On the basis of this similarity and the similarity of the physical properties of the two proteins, we now designate Protein X as A. vinelandii NADPH:ferredoxin reductase and its gene as the fpr gene. The protein has been overexpressed in its native background in A. vinelandii by using the broad host range multicopy plasmid, pKT230. In addition to being regulated by FdI, the fpr gene product is overexpressed when A. vinelandii is grown under N2-fixing conditions even though the fpr gene is not preceded by a nif specific promoter. By analogy to what is known about fpr expression in E. coli, we propose that FdI may exert its regulatory effect on fpr by interacting with the SoxRS regulon. PMID:7673160

  5. Overexpression of glutamine synthetases confers transgenic rice herbicide resistance

    Institute of Scientific and Technical Information of China (English)

    Sun Hui; Huang Qiman; Su Jin

    2005-01-01

    Glutamine synthetase (GS, E.C.6.3.1.2) is a key enzyme involved in the assimilation of inorganic nitrogen in higher plants and gram-negative microorganisms. GS is the targeting enzyme of a herbicide phosphinothricin (PPT) or Basta. In order to generate PPT-resistant transgenic rice via overexpression of GS, we constructed a plant expression vector p2GS harboring two different isoenzymes GS1 and GS2 cDNAs under the control of constitutive promoters of rice Act1 and maize Ubiquitin(Ubi) genes. The p2GS was introduced into rice genome by Agrobacterium-mediated transformation and confirmed by PCR and Southern blot hybridization. GS-transgene expression was first detected by Northern blot analyses. Results from Basta test indicated that GS-transgenic plants can tolerate as high as 0.3% Basta solution. In addition, our results also demonstrated that GS overexpression conferred transformed rice calli PPT resistance. Thus, GS cassette can serve as a selective marker gene instead of bar cassette for selection of PPT transformants.

  6. Nitrate metabolism in tobacco leaves overexpressing Arabidopsis nitrite reductase.

    Science.gov (United States)

    Davenport, Susie; Le Lay, Pascaline; Sanchez-Tamburrrino, Juan Pablo

    2015-12-01

    Primary nitrogen assimilation in plants includes the reduction of nitrite to ammonium in the chloroplasts by the enzyme nitrite reductase (NiR EC:1.7.7.1) or in the plastids of non-photosynthetic organs. Here we report on a study overexpressing the Arabidopsis thaliana NiR (AtNiR) gene in tobacco plants under the control of a constitutive promoter (CERV - Carnation Etched Ring Virus). The aim was to overexpress AtNiR in an attempt to alter the level of residual nitrite in the leaf which can act as precursor to the formation of nitrosamines. The impact of increasing the activity of AtNiR produced an increase in leaf protein and a stay-green phenotype in the primary transformed AtNiR population. Investigation of the T1 homozygous population demonstrated elevated nitrate reductase (NR) activity, reductions in leaf nitrite and nitrate and the amino acids proline, glutamine and glutamate. Chlorophyl content of the transgenic lines was increased, as evidenced by the stay-green phenotype. This reveals the importance of NiR in primary nitrogen assimilation and how modification of this key enzyme affects both the nitrogen and carbon metabolism of tobacco plants. PMID:26447683

  7. Over-expression of EGFR in Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    BO Ai-hua; HOU Jin-chao; LAN Yong-hao; TIAN Ya-ting; ZHANG Jun-yan

    2008-01-01

    Objective:To explore the relationship of overexpression of epidermal growth factor receptor(EGFR)in occurrence,development and treatment of breast cancer. Methods:Samples of 46 breast adenoma tissues and 86 breast cancer tissues were regularly dehydrate-fixed,embedded in paraffin,sliced in to 5 μm thick,stained with SABC immunohistochemistry and coloured with DAB. Results:The positive staining of EGFR was shown as brown- yellow and distributed in cytoplasm.The positive rates in the tissues of breast adenosis and breast cancer were 17.04%(6/46)and 56.98%(49/86)respectively.The positive rates of EGFR in the tissue of invasive ductal carcinoma was 64.49%(41/59),which was significantly higher than that in in situ carcinoma(P<0.05).The positive rate of lymph metastasis group was higher than that in non-lymph metastasis group (P<0.05). Conclusion:The overexpression of EGFR was related with occurrence,lymph metastasis and pathologic types of breast cancer.The examination of EGFR in the breast cancer can serve as a guidance for target chemotherapy.

  8. Decreased Xylitol Formation during Xylose Fermentation in Saccharomyces cerevisiae Due to Overexpression of Water-Forming NADH Oxidase

    Science.gov (United States)

    Zhang, Guo-Chang; Ding, Wen-Tao

    2012-01-01

    The recombinant xylose-fermenting Saccharomyces cerevisiae strain harboring xylose reductase (XR) and xylitol dehydrogenase (XDH) from Scheffersomyces stipitis requires NADPH and NAD+, creates cofactor imbalance, and causes xylitol accumulation during growth on d-xylose. To solve this problem, noxE, encoding a water-forming NADH oxidase from Lactococcus lactis driven by the PGK1 promoter, was introduced into the xylose-utilizing yeast strain KAM-3X. A cofactor microcycle was set up between the utilization of NAD+ by XDH and the formation of NAD+ by water-forming NADH oxidase. Overexpression of noxE significantly decreased xylitol formation and increased final ethanol production during xylose fermentation. Under xylose fermentation conditions with an initial d-xylose concentration of 50 g/liter, the xylitol yields for of KAM-3X(pPGK1-noxE) and control strain KAM-3X were 0.058 g/g xylose and 0.191 g/g, respectively, which showed a 69.63% decrease owing to noxE overexpression; the ethanol yields were 0.294 g/g for KAM-3X(pPGK1-noxE) and 0.211 g/g for the control strain KAM-3X, which indicated a 39.33% increase due to noxE overexpression. At the same time, the glycerol yield also was reduced by 53.85% on account of the decrease in the NADH pool caused by overexpression of noxE. PMID:22156411

  9. Depressive-like phenotype induced by AAV-mediated overexpression of human α-synuclein in midbrain dopaminergic neurons.

    Science.gov (United States)

    Caudal, D; Alvarsson, A; Björklund, A; Svenningsson, P

    2015-11-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by a progressive loss of nigral dopaminergic neurons and by the presence of aggregates containing α-synuclein called Lewy bodies. Viral vector-induced overexpression of α-synuclein in dopaminergic neurons represents a model of PD which recapitulates disease progression better than commonly used neurotoxin models. Previous studies using this model have reported motor and cognitive impairments, whereas depression, mood and anxiety phenotypes are less described. To investigate these psychiatric phenotypes, Sprague-Dawley rats received bilateral injections of a recombinant adeno-associated virus (AAV) vector expressing human α-synuclein or GFP into the substantia nigra pars compacta. Behavior was assessed at two timepoints: 3 and 8 weeks post-injection. We report that nigral α-synuclein overexpression led to a pronounced nigral dopaminergic cell loss accompanied by a smaller cell loss in the ventral tegmental area, and to a decreased striatal density of dopaminergic fibers. The AAV-α-synuclein group exhibited modest, but significant motor impairments 8 weeks after vector administration. The AAV-α-synuclein group displayed depressive-like behavior in the forced swim test after 3 weeks, and reduced sucrose preference at week 8. At both timepoints, overexpression of α-synuclein was linked to a hyperactive hypothalamic-pituitary-adrenal (HPA) axis regulation of corticosterone. The depressive-like phenotype was also correlated with decreased nigral brain-derived neurotrophic factor and spinophilin levels, and with decreased striatal levels of the activity-regulated cytoskeleton-associated protein. This study demonstrates that AAV-mediated α-synuclein overexpression in dopamine neurons is not only useful to model motor impairments of PD, but also depression. This study also provides evidence that depression in experimental Parkinsonism is correlated to dysregulation of the HPA axis and to

  10. Overexpression of MicroRNA-30b Improves Adenovirus-Mediated p53 Cancer Gene Therapy for Laryngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Liang Li

    2014-10-01

    Full Text Available MicroRNAs play important roles in laryngeal carcinoma and other cancers. However, the expression of microRNAs in paracancerous tissue has been studied less. Here, using laser capture microdissection (LCM, we detected the expression of microRNAs in paracancerous tissues. Among all down-regulated microRNAs in the center area of tumor tissues, only miR-30b expression was significantly reduced in paracancerous tissues compared to surgical margins. Therefore, to further investigate the effect of miR-30b on laryngeal carcinoma, we stably overexpressed miR-30b in laryngeal carcinoma cell line HEp-2 cells. It was found that although there was no significant difference in cell viability between miR-30b overexpressed cells and control HEp-2 cells, p53 expression was obviously enhanced in miR-30b overexpressed cells. Whether miR-30b could improve the anti-tumor effect of adenovirus-p53 (Ad-p53 in laryngeal carcinoma and other cancer cell lines was also evaluated. It was found that in miR-30b overexpressed HEp-2 cells, p53-mediated tumor cell apoptosis was obviously increased both in vitro and in vivo. MDM2-p53 interaction might be involved in miR-30b-mediated anti-tumor effect. Together, results suggested that miR-30b could modulate p53 pathway and enhance p53 gene therapy-induced apoptosis in laryngeal carcinoma, which could provide a novel microRNA target in tumor therapy.

  11. Metabolic hormone FGF21 is induced in ground squirrels during hibernation but its overexpression is not sufficient to cause torpor.

    Science.gov (United States)

    Nelson, Bethany T; Ding, Xunshan; Boney-Montoya, Jamie; Gerard, Robert D; Kliewer, Steven A; Andrews, Matthew T

    2013-01-01

    Hibernation is a natural adaptation that allows certain mammals to survive physiological extremes that are lethal to humans. Near freezing body temperatures, heart rates of 3-10 beats per minute, absence of food consumption, and depressed metabolism are characteristic of hibernation torpor bouts that are periodically interrupted by brief interbout arousals (IBAs). The molecular basis of torpor induction is unknown, however starved mice overexpressing the metabolic hormone fibroblast growth factor 21 (FGF21) promote fat utilization, reduce body temperature, and readily enter torpor-all hallmarks of mammalian hibernation. In this study we cloned FGF21 from the naturally hibernating thirteen-lined ground squirrel (Ictidomys tridecemlineatus) and found that levels of FGF21 mRNA in liver and FGF21 protein in serum are elevated during hibernation torpor bouts and significantly elevated during IBAs compared to summer active animals. The effects of artificially elevating circulating FGF21 concentrations 50 to 100-fold via adenoviral-mediated overexpression were examined at three different times of the year. This is the first time that a transgenic approach has been used in a natural hibernator to examine mechanistic aspects of hibernation. Surgically implanted transmitters measured various metrics of the hibernation phenotype over a 7-day period including changes in motor activity, heart rate and core body temperature. In April fed-state animals, FGF21 overexpression decreased blood insulin and free fatty acid concentrations, effects similar to those seen in obese mice. However, elevated FGF21 concentrations did not cause torpor in these fed-state animals nor did they cause torpor or affect metabolic parameters in fasted-state animals in March/April, August or October. We conclude that FGF21 is strongly regulated during torpor and IBA but that its overexpression is not sufficient to cause torpor in naturally hibernating ground squirrels. PMID:23301087

  12. Mitochondrial defects and neurodegeneration in mice overexpressing wild-type or G399S mutant HtrA2.

    Science.gov (United States)

    Casadei, Nicolas; Sood, Poonam; Ulrich, Thomas; Fallier-Becker, Petra; Kieper, Nicole; Helling, Stefan; May, Caroline; Glaab, Enrico; Chen, Jing; Nuber, Silke; Marcus, Katrin; Rapaport, Doron; Ott, Thomas; Riess, Olaf; Krüger, Rejko; Fitzgerald, Julia C

    2016-02-01

    The protease HtrA2 has a protective role inside mitochondria, but promotes apoptosis under stress. We previously identified the G399S HtrA2 mutation in Parkinson's disease (PD) patients and reported mitochondrial dysfunction in vitro. Mitochondrial dysfunction is a common feature of PD and related to neurodegeneration. Complete loss of HtrA2 has been shown to cause neurodegeneration in mice. However, the full impact of HtrA2 overexpression or the G399S mutation is still to be determined in vivo. Here, we report the first HtrA2 G399S transgenic mouse model. Our data suggest that the mutation has a dominant-negative effect. We also describe a toxic effect of wild-type (WT) HtrA2 overexpression. Only low overexpression of the G399S mutation allowed viable animals and we suggest that the mutant protein is likely unstable. This is accompanied by reduced mitochondrial respiratory capacity and sensitivity to apoptotic cell death. Mice overexpressing WT HtrA2 were viable, yet these animals have inhibited mitochondrial respiration and significant induction of apoptosis in the brain leading to motor dysfunction, highlighting the opposing roles of HtrA2. Our data further underscore the importance of HtrA2 as a key mediator of mitochondrial function and its fine regulatory role in cell fate. The location and abundance of HtrA2 is tightly controlled and, therefore, human mutations leading to gain- or loss of function could provide significant risk for PD-related neurodegeneration. PMID:26604148

  13. High-irradiance responses induced by far-red light in grass seedlings of the wild type or overexpressing phytochrome A

    International Nuclear Information System (INIS)

    The occurrence of phytochrome-mediated high irradiance responses (HIR), previously characterised largely in dicotyledonous plants, was investigated in Triticum aestivum L., Zea mays L., Lolium multiflorum Lam. and in both wild-type Oryza sativa L. and in transgenic plants overexpressing oat phytochrome A under the control of a 35S promoter. Coleoptile growth was promoted (maize, ryegrass) or inhibited (wild-type rice) by continuous far-red light (FRc). However, at equal fluences, hourly pulses of far-red light (FRp) were equally effective, indicating that the growth responses to FRc were not true HIR. In contrast, in maize and rice, FRc increased anthocyanin content in the coleoptile in a fluence-rate dependent manner. This response was a true HIR as FRp had reduced effects. In maize, anthocyanin levels were significantly higher under FRc than under continuous red light. In rice, overexpression of phytochrome A increased the inhibition of coleoptile growth and the levels of anthocyanin under FRc but not under FRp or under continuous red light. The effect of FRc was fluence-rate dependent. In light-grown rice, overexpression of phytochrome A reduced leaf-sheath length, impaired the response to supplementary far-red light, but did not affect the response to canopy shade-light. In grasses, typical HIR, i.e. fluence-rate dependent responses showing reciprocity failure, can be induced by FRc. Under FRc, overexpressed phytochrome A operates through this action mode in transgenic rice. (author)

  14. Pressure overload-induced hypertrophy in transgenic mice selectively overexpressing AT2 receptors in ventricular myocytes.

    Science.gov (United States)

    Yan, Xinhua; Schuldt, Adam J T; Price, Robert L; Amende, Ivo; Liu, Fen-Fen; Okoshi, Katashi; Ho, Kalon K L; Pope, Adèle J; Borg, Thomas K; Lorell, Beverly H; Morgan, James P

    2008-03-01

    The role of the angiotensin II type 2 (AT2) receptor in cardiac hypertrophy remains controversial. We studied the effects of AT2 receptors on chronic pressure overload-induced cardiac hypertrophy in transgenic mice selectively overexpressing AT2 receptors in ventricular myocytes. Left ventricular (LV) hypertrophy was induced by ascending aorta banding (AS). Transgenic mice overexpressing AT2 (AT2TG-AS) and nontransgenic mice (NTG-AS) were studied after 70 days of aortic banding. Nonbanded NTG mice were used as controls. LV function was determined by catheterization via LV puncture and cardiac magnetic resonance imaging. LV myocyte diameter and interstitial collagen were determined by confocal microscopy. Atrial natriuretic polypeptide (ANP) and brain natriuretic peptide (BNP) were analyzed by Northern blot. Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2, inducible nitric oxide synthase (iNOS), endothelial NOS, ERK1/2, p70S6K, Src-homology 2 domain-containing protein tyrosine phosphatase-1, and protein serine/threonine phosphatase 2A were analyzed by Western blot. LV myocyte diameter and collagen were significantly reduced in AT2TG-AS compared with NTG-AS mice. LV anterior and posterior wall thickness were not different between AT2TG-AS and NTG-AS mice. LV systolic and diastolic dimensions were significantly higher in AT2TG-AS than in NTG-AS mice. LV systolic pressure and end-diastolic pressure were lower in AT2TG-AS than in NTG-AS mice. ANP, BNP, and SERCA2 were not different between AT2TG-AS and NTG-AS mice. Phospholamban (PLB) and the PLB-to-SERCA2 ratio were significantly higher in AT2TG-AS than in NTG-AS mice. iNOS was higher in AT2TG-AS than in NTG-AS mice but not significantly different. Our results indicate that AT2 receptor overexpression modified the pathological hypertrophic response to aortic banding in transgenic mice. PMID:18178728

  15. Adipose Overexpression of Desnutrin Promotes Fatty Acid Use and Attenuates Diet-Induced Obesity

    OpenAIRE

    Ahmadian, Maryam; Duncan, Robin E.; Varady, Krista A.; Frasson, Danubia; Hellerstein, Marc K.; Birkenfeld, Andreas L.; Samuel, Varman T.; Shulman, Gerald I.; Wang, Yuhui; Kang, Chulho; Sul, Hei Sook

    2009-01-01

    OBJECTIVE To investigate the role of desnutrin in adipose tissue triacylglycerol (TAG) and fatty acid metabolism. RESEARCH DESIGN AND METHODS We generated transgenic mice overexpressing desnutrin (also called adipose triglyceride lipase [ATGL]) in adipocytes (aP2-desnutrin) and also performed adenoviral-mediated overexpression of desnutrin in 3T3-L1CARΔ1 adipocytes. RESULTS aP2-desnutrin mice were leaner with decreased adipose tissue TAG content and smaller adipocyte size. Overexpression of d...

  16. Induced overexpression of mitochondrial Mn-superoxide dismutase extends the life span of adult Drosophila melanogaster.

    OpenAIRE

    Sun, Jingtao; Folk, Donna; Bradley, Timothy J.; Tower, John

    2002-01-01

    A transgenic system ("FLP-out") based on yeast FLP recombinase allowed induced overexpression of MnSOD enzyme in adult Drosophila melanogaster. With FLP-out a brief heat pulse (HP) of young, adult flies triggered the rearrangement and subsequent expression of a MnSOD transgene throughout the adult life span. Control (no HP) and overexpressing (HP) flies had identical genetic backgrounds. The amount of MnSOD enzyme overexpression achieved varied among six independent transgenic lines, with inc...

  17. Reducing costs by reducing size

    International Nuclear Information System (INIS)

    The present paper discusses briefly the many factors, including capital cost, which have to be taken into account in determining whether a series of power stations based on a small nuclear plant can be competitive with a series based on traditional large unit sizes giving the guaranteed level of supply. The 320 MWe UK/US Safe Integral Reactor is described as a good example of how the factors discussed can be beneficially incorporated into a design using proven technology. Finally it goes on to illustrate how the overall costs of a generating system can indeed by reduced by use of the 320 MWe Safe Integral Reactor rather than conventional units of around 1200 MWe. (author). 9 figs

  18. Overexpression of Eg5 correlates with high grade astrocytic neoplasm.

    Science.gov (United States)

    Liu, Liqiong; Liu, Xichun; Mare, Marcus; Dumont, Aaron S; Zhang, Haitao; Yan, Dong; Xiong, Zhenggang

    2016-01-01

    To investigate the relationship between Eg5 and histopathological grade of astrocytoma, Eg5 expression was evaluated by immunohistochemical examination on 88 specimens including 25 cases of glioblastoma (WHO grade IV), 22 cases of anaplastic astrocytoma (WHO grade III), 20 cases of diffuse astrocytoma (WHO grade II), and 21 cases of pilocytic astrocytoma (WHO grade I). The histopathological characteristics and Eg5 expression level of each tumor were assessed and statistically analyzed. Astrocytic tumors exhibited significant correlation of expression of Eg5 with higher WHO histopathological grades (p astrocytoma, 6-36% (mean 18.60%) of neoplastic cells in diffuse astrocytoma, and 2-28% (mean 13.48%) of neoplastic cells in pilocytic astrocytoma. In conclusion, overexpression of Eg5 associates with high-grade astrocytic neoplasm, and it may represent an independent diagnostic and prognostic factor in grading astrocytic tumors and predicting prognosis of astrocytic tumor patients. PMID:26456023

  19. CENPA overexpression promotes genome instability in pRb-depleted human cells

    Directory of Open Access Journals (Sweden)

    Lentini Laura

    2009-12-01

    Full Text Available Abstract Background Aneuploidy is a hallmark of most human cancers that arises as a consequence of chromosomal instability and it is frequently associated with centrosome amplification. Functional inactivation of the Retinoblastoma protein (pRb has been indicated as a cause promoting chromosomal instability as well centrosome amplification. However, the underlying molecular mechanism still remains to be clarified. Results Here we show that pRb depletion both in wild type and p53 knockout HCT116 cells was associated with the presence of multipolar spindles, anaphase bridges, lagging chromosomes and micronuclei harbouring whole chromosomes. In addition aneuploidy caused by pRb acute loss was not affected by p53 loss. Quantitative real-time RT-PCR showed that pRB depletion altered expression of genes involved in centrosome duplication, kinetochore assembly and in the Spindle Assembly Checkpoint (SAC. However, despite MAD2 up-regulation pRb-depleted cells seemed to have a functional SAC since they arrested in mitosis after treatments with mitotic poisons. Moreover pRb-depleted HCT116 cells showed BRCA1 overexpression that seemed responsible for MAD2 up-regulation. Post-transcriptional silencing of CENPA by RNA interference, resulting in CENP-A protein levels similar to those present in control cells greatly reduced aneuploid cell numbers in pRb-depleted cells. Conclusion Altogether our findings indicate a novel aspect of pRb acute loss that promotes aneuploidy mainly by inducing CENPA overexpression that in turn might induce micronuclei by affecting the correct attachment of spindle microtubules to kinetochores.

  20. Transgenic overexpression of LARGE induces α-dystroglycan hyperglycosylation in skeletal and cardiac muscle.

    Directory of Open Access Journals (Sweden)

    Martin Brockington

    Full Text Available BACKGROUND: LARGE is one of seven putative or demonstrated glycosyltransferase enzymes defective in a common group of muscular dystrophies with reduced glycosylation of α-dystroglycan. Overexpression of LARGE induces hyperglycosylation of α-dystroglycan in both wild type and in cells from dystroglycanopathy patients, irrespective of their primary gene defect, restoring functional glycosylation. Viral delivery of LARGE to skeletal muscle in animal models of dystroglycanopathy has identical effects in vivo, suggesting that the restoration of functional glycosylation could have therapeutic applications in these disorders. Pharmacological strategies to upregulate Large expression are also being explored. METHODOLOGY/PRINCIPAL FINDINGS: In order to asses the safety and efficacy of long term LARGE over-expression in vivo, we have generated four mouse lines expressing a human LARGE transgene. On observation, LARGE transgenic mice were indistinguishable from the wild type littermates. Tissue analysis from young mice of all four lines showed a variable pattern of transgene expression: highest in skeletal and cardiac muscles, and lower in brain, kidney and liver. Transgene expression in striated muscles correlated with α-dystroglycan hyperglycosylation, as determined by immunoreactivity to antibody IIH6 and increased laminin binding on an overlay assay. Other components of the dystroglycan complex and extracellular matrix ligands were normally expressed, and general muscle histology was indistinguishable from wild type controls. Further detailed muscle physiological analysis demonstrated a loss of force in response to eccentric exercise in the older, but not in the younger mice, suggesting this deficit developed over time. However this remained a subclinical feature as no pathology was observed in older mice in any muscles including the diaphragm, which is sensitive to mechanical load-induced damage. CONCLUSIONS/SIGNIFICANCE: This work shows that

  1. Identification of a novel topoisomerase inhibitor effective in cells overexpressing drug efflux transporters.

    Directory of Open Access Journals (Sweden)

    Walid Fayad

    Full Text Available BACKGROUND: Natural product structures have high chemical diversity and are attractive as lead structures for discovery of new drugs. One of the disease areas where natural products are most frequently used as therapeutics is oncology. METHOD AND FINDINGS: A library of natural products (NCI Natural Product set was screened for compounds that induce apoptosis of HCT116 colon carcinoma cells using an assay that measures an endogenous caspase-cleavage product. One of the apoptosis-inducing compounds identified in the screen was thaspine (taspine, an alkaloid from the South American tree Croton lechleri. The cortex of this tree is used for medicinal purposes by tribes in the Amazonas basin. Thaspine was found to induce conformational activation of the pro-apoptotic proteins Bak and Bax, mitochondrial cytochrome c release and mitochondrial membrane permeabilization in HCT116 cells. Analysis of the gene expression signature of thaspine-treated cells suggested that thaspine is a topoisomerase inhibitor. Inhibition of both topoisomerase I and II was observed using in vitro assays, and thaspine was found to have a reduced cytotoxic effect on a cell line with a mutated topoisomerase II enzyme. Interestingly, in contrast to the topoisomerase II inhibitors doxorubicin, etoposide and mitoxantrone, thaspine was cytotoxic to cell lines overexpressing the PgP or MRP drug efflux transporters. We finally show that thaspine induces wide-spread apoptosis in colon carcinoma multicellular spheroids and that apoptosis is induced in two xenograft mouse models in vivo. CONCLUSIONS: The alkaloid thaspine from the cortex of Croton lechleri is a dual topoisomerase inhibitor effective in cells overexpressing drug efflux transporters and induces wide-spread apoptosis in multicellular spheroids.

  2. Over-expression of tetraspanin 8 in malignant glioma regulates tumor cell progression

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Si-Jian [Department of Neurosurgery, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025 (China); Wu, Yue-Bing [Department of Internal Medicine Oncology, Hubei Cancer Hospital, Wuhan, Hubei 430079 (China); Cai, Shang [Department of Radiotherapy and Oncology, the Second Affiliated Hospital of Soochow University, Suzhou 21500 (China); Pan, Yi-Xin; Liu, Wei [Department of Stereotactic and Functional Neurosurgery, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Bian, Liu-Guan [Department of Neurosurgery, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025 (China); Sun, Bomin [Department of Stereotactic and Functional Neurosurgery, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Sun, Qing-Fang, E-mail: sunqingfang11@163.com [Department of Neurosurgery, Rui Jin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025 (China)

    2015-03-13

    Tumor cell invasion and proliferation remain the overwhelming causes of death for malignant glioma patients. To establish effective therapeutic methods, new targets implied in these processes have to be identified. Tetraspanin 8 (Tspn8) forms complexes with a large variety of trans-membrane and/or cytosolic proteins to regulate several important cellular functions. In the current study, we found that Tspn8 was over-expressed in multiple clinical malignant glioma tissues, and its expression level correlated with the grade of tumors. Tspn8 expression in malignant glioma cells (U251MG and U87MG lines) is important for cell proliferation and migration. siRNA-mediated knockdown of Tspn8 markedly reduced in vitro proliferation and migration of U251MG and U87MG cells. Meanwhile, Tspn8 silencing also increased the sensitivity of temozolomide (TMZ), and significantly increased U251MG or U87MG cell death and apoptosis by TMZ were achieved with Tspn8 knockdown. We observed that Tspn8 formed a complex with activated focal adhesion kinase (FAK) in both human malignant glioma tissues and in above glioma cells. This complexation appeared required for FAK activation, since Tspn8 knockdown inhibited FAK activation in U251MG and U87MG cells. These results provide evidence that Tspn8 contributes to the pathogenesis of glioblastoma probably by promoting proliferation, migration and TMZ-resistance of glioma cells. Therefore, targeting Tspn8 may provide a potential therapeutic intervention for malignant glioma. - Highlights: • Tspn8 is over-expressed in multiple clinical malignant glioma tissues. • Tspn8 expression is correlated with the grade of malignant gliomas. • Tspn8 knockdown suppresses U251MG/U87MG proliferation and in vitro migration. • Tspn8 knockdown significantly increases TMZ sensitivity in U251MG/U87MG cells. • Tspn8 forms a complex with FAK, required for FAK activation.

  3. Over-expression of tetraspanin 8 in malignant glioma regulates tumor cell progression

    International Nuclear Information System (INIS)

    Tumor cell invasion and proliferation remain the overwhelming causes of death for malignant glioma patients. To establish effective therapeutic methods, new targets implied in these processes have to be identified. Tetraspanin 8 (Tspn8) forms complexes with a large variety of trans-membrane and/or cytosolic proteins to regulate several important cellular functions. In the current study, we found that Tspn8 was over-expressed in multiple clinical malignant glioma tissues, and its expression level correlated with the grade of tumors. Tspn8 expression in malignant glioma cells (U251MG and U87MG lines) is important for cell proliferation and migration. siRNA-mediated knockdown of Tspn8 markedly reduced in vitro proliferation and migration of U251MG and U87MG cells. Meanwhile, Tspn8 silencing also increased the sensitivity of temozolomide (TMZ), and significantly increased U251MG or U87MG cell death and apoptosis by TMZ were achieved with Tspn8 knockdown. We observed that Tspn8 formed a complex with activated focal adhesion kinase (FAK) in both human malignant glioma tissues and in above glioma cells. This complexation appeared required for FAK activation, since Tspn8 knockdown inhibited FAK activation in U251MG and U87MG cells. These results provide evidence that Tspn8 contributes to the pathogenesis of glioblastoma probably by promoting proliferation, migration and TMZ-resistance of glioma cells. Therefore, targeting Tspn8 may provide a potential therapeutic intervention for malignant glioma. - Highlights: • Tspn8 is over-expressed in multiple clinical malignant glioma tissues. • Tspn8 expression is correlated with the grade of malignant gliomas. • Tspn8 knockdown suppresses U251MG/U87MG proliferation and in vitro migration. • Tspn8 knockdown significantly increases TMZ sensitivity in U251MG/U87MG cells. • Tspn8 forms a complex with FAK, required for FAK activation

  4. Muscle cell atrophy induced by HSP gene silencing was counteracted by HSP overexpression

    Science.gov (United States)

    Choi, Inho; Lee, Joo-Hee; Nikawa, Takeshi; Gwag, Taesik; Park, Kyoungsook; Park, Junsoo

    Heat shock proteins (HSP), as molecular chaperones, are known to assist protein quality control under various stresses. Although overexpression of HSP70 was found to contribute to muscle size retention under an unloading condition, it remains largely unclarified whether muscle atrophy is induced by active suppression of HSP expression. In this study, we pre-treated Hsp70 siRNA to rat L6 cells for the HSP gene silencing, and determined myotube diameter, HSP72 expression and anabolic and catabolic signaling activities in the absence or presence of triterpene celastrol (CEL), the HSP70 inducer. Relative to a negative control (NC), muscle cell diameter was reduced 0.89-fold in the siRNA-treated group, increased 1.2-fold in the CEL-treated group and retained at the size of NC in the siRNA+CEL group. HSP72 expression was decreased 0.35-fold by siRNA whereas the level was increased 6- to 8-fold in the CEL and siRNA+CEL groups. Expression of FoxO3 and atrogin-1 was increased 1.8- to 4.8-fold by siRNA, which was abolished by CEL treatment. Finally, phosphorylation of Akt1, S6K and ERK1/2 was not affected by siRNA, but was elevated 2- to 6-fold in the CEL and siRNA+CEL groups. Taken together, HSP downregulation by Hsp gene silencing led to muscle cell atrophy principally via increases in catabolic activities and that such anti-atrophic effect was counteracted by HSP overexpression.

  5. Overexpression of the Eggplant (Solanum melongena) NAC Family Transcription Factor SmNAC Suppresses Resistance to Bacterial Wilt.

    Science.gov (United States)

    Na, Chen; Shuanghua, Wu; Jinglong, Fu; Bihao, Cao; Jianjun, Lei; Changming, Chen; Jin, Jiang

    2016-01-01

    Bacterial wilt (BW) is a serious disease that affects eggplant (Solanum melongena) production. Although resistance to this disease has been reported, the underlying mechanism is unknown. In this study, we identified a NAC family transcription factor (SmNAC) from eggplant and characterized its expression, its localization at the tissue and subcellular levels, and its role in BW resistance. To this end, transgenic eggplant lines were generated in which the expression of SmNAC was constitutively up regulated or suppressed using RNAi. The results indicated that overexpression of SmNAC decreases resistance to BW. Moreover, SmNAC overexpression resulted in the reduced accumulation of the plant immune signaling molecule salicylic acid (SA) and reduced expression of ICS1 (a gene that encode isochorismate synthase 1, which is involved in SA biosynthesis). We propose that reduced SA content results in increased bacterial wilt susceptibility in the transgenic lines. Our results provide important new insights into the regulatory mechanisms of bacterial wilt resistance in eggplant. PMID:27528282

  6. Fascin overexpression promotes neoplastic progression in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Fascin is a globular actin cross-linking protein, which plays a major role in forming parallel actin bundles in cell protrusions and is found to be associated with tumor cell invasion and metastasis in various type of cancers including oral squamous cell carcinoma (OSCC). Previously, we have demonstrated that fascin regulates actin polymerization and thereby promotes cell motility in K8-depleted OSCC cells. In the present study we have investigated the role of fascin in tumor progression of OSCC. To understand the role of fascin in OSCC development and/or progression, fascin was overexpressed along with vector control in OSCC derived cells AW13516. The phenotype was studied using wound healing, Boyden chamber, cell adhesion, Hanging drop, soft agar and tumorigenicity assays. Further, fascin expression was examined in human OSCC samples (N = 131) using immunohistochemistry and level of its expression was correlated with clinico-pathological parameters of the patients. Fascin overexpression in OSCC derived cells led to significant increase in cell migration, cell invasion and MMP-2 activity. In addition these cells demonstrated increased levels of phosphorylated AKT, ERK1/2 and JNK1/2. Our in vitro results were consistent with correlative studies of fascin expression with the clinico-pathological parameters of the OSCC patients. Fascin expression in OSCC showed statistically significant correlation with increased tumor stage (P = 0.041), increased lymph node metastasis (P = 0.001), less differentiation (P = 0.005), increased recurrence (P = 0.038) and shorter survival (P = 0.004) of the patients. In conclusion, our results indicate that fascin promotes tumor progression and activates AKT and MAPK pathways in OSCC-derived cells. Further, our correlative studies of fascin expression in OSCC with clinico-pathological parameters of the patients indicate that fascin may prove to be useful in prognostication and treatment of OSCC

  7. Overexpression of Androgen Receptors in Target Musculature Confers Androgen Sensitivity to Motoneuron Dendrites

    OpenAIRE

    Huguenard, Anna L.; Fernando, Shannon M.; Monks, D. Ashley; Sengelaub, Dale R.

    2010-01-01

    Androgen sensitivity of motoneuron dendrites is conferred indirectly via the enrichment of androgen receptors in the musculature in transgenic rats overexpressing androgen receptors in skeletal muscle.

  8. Correlation between human papillomavirus and p16 overexpression in oropharyngeal tumours

    DEFF Research Database (Denmark)

    Grønhøj Larsen, C; Gyldenløve, M; Jensen, D H; Therkildsen, M H; Kiss, Katalin; Norrild, B; Konge, L; von Buchwald, C

    2014-01-01

    A significant proportion of squamous cell carcinomas of the oropharynx (OP-SCC) are related to human papillomavirus (HPV) infection and p16 overexpression. This subgroup proves better prognosis and survival but no evidence exists on the correlation between HPV and p16 overexpression based on diag...... diagnostic measures and definition of p16 overexpression. We evaluated means of p16 and HPV diagnostics, and quantified overexpression of p16 in HPV-positive and -negative OP-SCCs by mode of immunohistochemical staining of carcinoma cells....

  9. Overexpression of microRNA-124 promotes the neuronal differentiation of bone marrow-derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Defeng Zou; Yi Chen; Yaxin Han; Chen Lv; Guanjun Tu

    2014-01-01

    microRNAs (miRNAs) play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124 (miR-124) overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs inbone marrow-derived mesen-chymal stem cells, neural stem cells and neurons. miR-124 expression was substantially reduced inbone marrow-derived mesenchymal stem cells compared with the other cell types. We con-structed a lentiviral vector overexpressing miR-124 and transfected it intobone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markersβ-III tu-bulin and microtubule-associated protein-2 were signiifcantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These re-sults suggest that miR-124 plays an important role in the differentiation ofbone marrow-derived mesenchymal stem cells into neurons. Our ifndings should facilitate the development of novel strategies for enhancing the therapeutic efifcacy ofbone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.

  10. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves

    Science.gov (United States)

    Tondo, María Laura; Delprato, María Laura; Kraiselburd, Ivana; Fernández Zenoff, María Verónica; Farías, María Eugenia; Orellano, Elena G.

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance. PMID:26990197

  11. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

  12. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves.

    Directory of Open Access Journals (Sweden)

    María Laura Tondo

    Full Text Available Xanthomonas citri subsp. citri (Xcc is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG, carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance.

  13. KatG, the Bifunctional Catalase of Xanthomonas citri subsp. citri, Responds to Hydrogen Peroxide and Contributes to Epiphytic Survival on Citrus Leaves.

    Science.gov (United States)

    Tondo, María Laura; Delprato, María Laura; Kraiselburd, Ivana; Fernández Zenoff, María Verónica; Farías, María Eugenia; Orellano, Elena G

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker. This bacterium is exposed to reactive oxygen species (ROS) at different points during its life cycle, including those normally produced by aerobic respiration or upon exposition to ultraviolet (UV) radiation. Moreover, ROS are key components of the host immune response. Among enzymatic ROS-detoxifying mechanisms, catalases eliminate H2O2, avoiding the potential damage caused by this specie. Xcc genome includes four catalase genes. In this work, we studied the physiological role of KatG, the only bifunctional catalase of Xcc, through the construction and characterization of a modified strain (XcckatG), carrying an insertional mutation in the katG gene. First, we evaluated the involvement of KatG in the bacterial adaptive response to H2O2. XcckatG cultures exhibited lower catalase activity than those of the wild-type strain, and this activity was not induced upon treatment with sub-lethal doses of H2O2. Moreover, the KatG-deficient mutant exhibited decreased tolerance to H2O2 toxicity compared to wild-type cells and accumulated high intracellular levels of peroxides upon exposure to sub-lethal concentrations of H2O2. To further study the role of KatG in Xcc physiology, we evaluated bacterial survival upon exposure to UV-A or UV-B radiation. In both conditions, XcckatG showed a high mortality in comparison to Xcc wild-type. Finally, we studied the development of bacterial biofilms. While structured biofilms were observed for the Xcc wild-type, the development of these structures was impaired for XcckatG. Based on these results, we demonstrated that KatG is responsible for Xcc adaptive response to H2O2 and a key component of the bacterial response to oxidative stress. Moreover, this enzyme plays an important role during Xcc epiphytic survival, being essential for biofilm formation and UV resistance. PMID:26990197

  14. COMPARED ANALYSIS OF CATALASE AND PEROXIDASE ACTIVITY IN CELLULOLYTIC FUNGUS TRICHODERMA REESEI GROWN ON MEDIUM WITH DIFFERENT CONCENTRATIONS OF GRINDED WHEAT AND BARLEY STRAWS

    OpenAIRE

    Elena Ciornea; Tamara Barbaneagra; Alexandru Manoliu; Mihaela Cristica

    2010-01-01

    The purpose of this study was to assess the evolution of catalase and peroxidase activity in Trichoderma reesei grown on medium containing grinded wheat and barley straws. Carbon source of cultivation medium - glucose was replaced by various concentrations of grinded wheat and barley straws, finally resulting three experimental variants as follows: V1 = 20 g/l, V2 = 30 g/l, V3 = 40 g/l. ĂŽn addition to these variants a control sample was added in which composition remainded unchanged. The cat...

  15. γ-Aminobutyric acid transporter (GAT1) overexpression in mouse affects the testicular morphology

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    γ-Aminobutyric acid and GABAergic receptors were previously reported to be distributed in reproductive sys tems besides CNS and predicted to participate in the mod ulation of testicular function. γ-Aminobutyric acid trans porter was implicated to be involved in this process. How ever, the potential role of γ-aminobutyric transporter in testis has not been explored. In this study, we investi gated the existence of mouse γ-aminobutyric acid trans porter subtype I (mGAT1) in testis. Wild-type and trans genic mice, which overexpressing mGAT1 in a variety of tissues, especially in testis, were primarily studied to ap proach the profile of mGAT1 in testis. Mice with overex pressed mGAT1 develop normally but with reduced mass and size of testis as compared with wild-type. Testicu lar morphology of transgenic mice exhibited overt abnor malities including focal damage of the spermatogenic ep ithelium accompanied by capillaries proliferation and in creased diameter of seminiferous tubules lumen. Reduced number of spermatids was also found in some seminiferous tubules. Our results clearly demonstrate the presence of GAT1 in mouse testis and imply that GAT1 is possibly involved in testicular function.

  16. Overexpression of Soybean Isoflavone Reductase (GmIFR) Enhances Resistance to Phytophthora sojae in Soybean.

    Science.gov (United States)

    Cheng, Qun; Li, Ninghui; Dong, Lidong; Zhang, Dayong; Fan, Sujie; Jiang, Liangyu; Wang, Xin; Xu, Pengfei; Zhang, Shuzhen

    2015-01-01

    Isoflavone reductase (IFR) is an enzyme involved in the biosynthetic pathway of isoflavonoid phytoalexin in plants. IFRs are unique to the plant kingdom and are considered to have crucial roles in plant response to various biotic and abiotic environmental stresses. Here, we report the characterization of a novel member of the soybean isoflavone reductase gene family GmIFR. Overexpression of GmIFR transgenic soybean exhibited enhanced resistance to Phytophthora sojae. Following stress treatments, GmIFR was significantly induced by P. sojae, ethephon (ET), abscisic acid (placeCityABA), salicylic acid (SA). It is located in the cytoplasm when transiently expressed in soybean protoplasts. The daidzein levels reduced greatly for the seeds of transgenic plants, while the relative content of glyceollins in transgenic plants was significantly higher than that of non-transgenic plants. Furthermore, we found that the relative expression levels of reactive oxygen species (ROS) of transgenic soybean plants were significantly lower than those of non-transgenic plants after incubation with P. sojae, suggesting an important role of GmIFR might function as an antioxidant to reduce ROS in soybean. The enzyme activity assay suggested that GmIFR has isoflavone reductase activity. PMID:26635848

  17. High mobility group A1 protein expression reduces the sensitivity of colon and thyroid cancer cells to antineoplastic drugs

    OpenAIRE

    D’Angelo, Daniela; Mussnich, Paula; De Rosa, Roberta; Bianco, Roberto; Tortora, Giampaolo; Fusco, Alfredo

    2014-01-01

    Background Development of resistance to conventional drugs and novel biological agents often impair long-term chemotherapy. HMGA gene overexpression is often associated with antineoplastic drug resistance and reduced survival. Inhibition of HMGA expression in thyroid cancer cells reduces levels of ATM protein, the main cellular sensor of DNA damage, and enhances cellular sensitivity to DNA-damaging agents. HMGA1 overexpression promotes chemoresistance to gemcitabine in pancreatic adenocarcino...

  18. Overexpression of SOS (Salt Overly Sensitive)Genes Increases Salt Tolerance in Transgenic Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Qing Yang; Zhi-Zhong Chen; Xiao-Feng Zhoua; Hai-Bo Yin; Xia Li; Xiu-Fang Xin; Xu-Hui Hong; Jian-Kang Zhu; Zhizhong Gong

    2009-01-01

    Soil salinity is a major abiotic stress that decreases plant growth and productivity. Recently, it was reported that plants overexpressing AtNHX1 or SOS1 have significantly increased salt tolerance. To test whether overexpression of multiple genes can improve plant salt tolerance even more, we produced six different transgenic Arabidopsis plants that overexpress AtNHX1, SOS3, AtNHXl + SOS3, SOS1, SOS2 + SOS3, or SOS1 + SOS2 + SOS3. Northern blot analyses confirmed the presence of high levels of the relevant gene transcripts in transgenic plants. Transgenic Arabidopsis plants overexpressing AtNHX1 alone did not present any significant increase in salt tolerance, contrary to earlier reports. We found that transgenic plants overexpressing SOS3 exhibit increased salt tolerance similar to plants overexpressing SOS1. Moreover, salt tolerance of transgenic plants overexpressing AtNHXl + SOS3, 50S2 + SOS3, or SOS1 + SOS2 +SOS3, respectively, appeared similar to the tolerance of transgenic plants overexpressing either SOS1 or SOS3 alone.

  19. COX-2 overexpression in resected pancreatic head adenocarcinomas correlates with favourable prognosis

    OpenAIRE

    Pomianowska, Ewa; Schjølberg, Aasa R.; Clausen, Ole P F; Gladhaug, Ivar P

    2014-01-01

    Background Overexpression of cyclooxygenase-2 (COX-2) has been implicated in oncogenesis and progression of adenocarcinomas of the pancreatic head. The data on the prognostic importance of COX expression in these tumours is inconsistent and conflicting. We evaluated how COX-2 overexpression affected overall postoperative survival in pancreatic head adenocarcinomas. Methods The study included 230 conse...

  20. Combined gene overexpression of neuropeptide Y and its receptor Y5 in the hippocampus suppresses seizures

    DEFF Research Database (Denmark)

    Gøtzsche, Casper René; Nikitidou, Litsa; Sørensen, Andreas; Olesen, Mikkel V; Sørensen, Gunnar; Christiansen, Søren Hofman Oliveira; Ängehagen, Mikael; Woldbye, David Paul Drucker; Kokaia, Merab

    2012-01-01

    the hippocampus strengthened the seizure-suppressant effect of transgene Y2 receptors. Here we show for the first time that another neuropeptide Y receptor, Y5, can also be overexpressed in the hippocampus. However, unlike Y2 receptor overexpression, transgene Y5 receptors in the hippocampus had no...

  1. Regulation of [Ca2+](i) homeostasis in MRP1 overexpressing cells

    NARCIS (Netherlands)

    Filipeanu, C.M; Nelemans, Adriaan; Veldman, Robert Jan; de Zeeuw, Dick; Kok, Jan Willem

    2000-01-01

    Regulation of capacitative Ca2+ entry,vas studied in two different multidrug resistance (MDR) protein (MRP1) overexpressing cell lines, HT29(col) and GLC4/ADR. MRP1 overexpression was accompanied by a decreased response to thapsigargin, Moreover, inhibition of capacitative Ca2+ entry by D,L-threo-1-

  2. Adult T-cell leukemia cells overexpress Wnt5a and promote osteoclast differentiation

    OpenAIRE

    Bellon, Marcia; Ko, Nga Ling; Lee, Min-Jung; Yao, Yuan; Waldmann, Thomas A; Trepel, Jane B; Nicot, Christophe

    2013-01-01

    Profiling of the Wnt/β-catenin pathway reveals overexpression of Wnt5a, LEF-1 and TCF-1 in ATL patient cells.ATL cells overexpress Wnt5a, which enhances osteoclastogenesis and may contribute to the osteolytic bone lesions and hypercalcemia.

  3. Overexpression of the AtSHI gene in poinsettia, Euphorbia pulcherrima, results in compact plants.

    Science.gov (United States)

    Islam, M Ashraful; Lütken, Henrik; Haugslien, Sissel; Blystad, Dag-Ragnar; Torre, Sissel; Rolcik, Jakub; Rasmussen, Søren K; Olsen, Jorunn E; Clarke, Jihong Liu

    2013-01-01

    Euphorbia pulcherrima, poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact poinsettia plants with desirable height and reduce the utilization of growth retardants, the Arabidopsis SHORT INTERNODE (AtSHI) gene controlled by the cauliflower mosaic virus 35S promoter was introduced into poinsettia by Agrobacterium-mediated transformation. Three independent transgenic lines were produced and stable integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21-52%) and internode lengths (31-49%) were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed transgenic line (TL1). The indole-3-acetic acid (IAA) content appeared lower (11-31% reduction) in the transgenic lines compared to the wild type (WT) controls, with the lowest level (31% reduction) in TL1. Total internode numbers, bract numbers and bract area were significantly reduced in all transgenic lines in comparison with the WT controls. Only TL1 showed significantly lower plant diameter, total leaf area and total dry weight, whereas none of the AtSHI expressing lines showed altered timing of flower initiation, cyathia abscission or bract necrosis. This study demonstrated that introduction of the AtSHI gene into poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that AtSHI gene was overexpressed in poinsettia and transgenic poinsettia plants with compact growth were produced. PMID:23308204

  4. HMGA1 overexpression in adipose tissue impairs adipogenesis and prevents diet-induced obesity and insulin resistance

    Science.gov (United States)

    Arce-Cerezo, Altamira; García, Miquel; Rodríguez-Nuevo, Aida; Crosa-Bonell, Mireia; Enguix, Natalia; Peró, Albert; Muñoz, Sergio; Roca, Carles; Ramos, David; Franckhauser, Sylvie; Elias, Ivet; Ferre, Tura; Pujol, Anna; Ruberte, Jesús; Villena, Josep A.; Bosch, Fàtima; Riu, Efrén

    2015-01-01

    High-Mobility-Group-A1 (HMGA1) proteins are non-histone proteins that regulate chromatin structure and gene expression during embryogenesis, tumourigenesis and immune responses. In vitro studies suggest that HMGA1 proteins may be required to regulate adipogenesis. To examine the role of HMGA1 in vivo, we generated transgenic mice overexpressing HMGA1 in adipose tissues. HMGA1 transgenic mice showed a marked reduction in white and brown adipose tissue mass that was associated with downregulation of genes involved in adipogenesis and concomitant upregulation of preadipocyte markers. Reduced adipogenesis and decreased fat mass were not associated with altered glucose homeostasis since HMGA1 transgenic mice fed a regular-chow diet exhibited normal glucose tolerance and insulin sensitivity. However, when fed a high-fat diet, overexpression of HMGA1 resulted in decreased body-weight gain, reduced fat mass, but improved insulin sensitivity and glucose tolerance. Although HMGA1 transgenic mice exhibited impaired glucose uptake in adipose tissue due to impaired adipogenesis, the increased glucose uptake observed in skeletal muscle may account for the improved glucose homeostasis. Our results indicate that HMGA1 plays an important function in the regulation of white and brown adipogenesis in vivo and suggests that impaired adipocyte differentiation and decreased fat mass is not always associated with impaired whole-body glucose homeostasis. PMID:26411793

  5. Geldanamycin inhibits proliferation and motility of Her2/neu-overexpressing SK-Br3 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Ren Yu; Wang Ke; He Jianjun; Chen Wuke; Ma Qingyong

    2008-01-01

    Objective Benzoquinone ansamycin antibiotic, geldanamycin (GA), is a new anticancer agent that could inhibit Hsp90 by occupying its NH2-terminal ATP-binding site. This study was to investigate the antitumor efficacy of GA on Her2/neu tyrosine kinase overexpressing human breast cancer cell line SKBr3. Methods The degradation of Her2/neu tyrosine kinase was analyzed by Western blotting, the proliferation index was determined by MTT assay,cell cycle distribution was detected by flow cytometry, Cyclin D1 mRNA transcription was measured by RT-PCR and real-time PCR, and cell motility was evaluated by the cell culture insert model. Results GA induced a dose- and a time-dependent degradation of the Her2/neu tyrosine kinase protein and concurrently, the inhibition of cancer cell proliferation. The antitumor effects mediated by GA included: GA treatment decreased the survival rates of cancer cells,and led to a dase-dependent G1 arrest. Furthermore, this antitumor effect was proved to be related to declined transcription of Cyclin D1. Concurrently, the motility of cancer cells was reduced by GA. Conclusion GA treatment could induce the degradation of Her2/neu tyrnsine kinase efficiently, inhibit cancer cell proliferation and reduce motility in Her2/nen tyrosine kinase overexpressed human breast cancer cell line SKBr3.

  6. Overexpression of a host factor TOM1 inhibits tomato mosaic virus propagation and suppression of RNA silencing.

    Science.gov (United States)

    Hagiwara-Komoda, Yuka; Hirai, Katsuyuki; Mochizuki, Atsuko; Nishiguchi, Masamichi; Meshi, Tetsuo; Ishikawa, Masayuki

    2008-06-20

    A plant integral membrane protein TOM1 is involved in the multiplication of Tomato mosaic virus (ToMV). TOM1 interacts with ToMV replication proteins and has been suggested to tether the replication proteins to the membranes where the viral RNA synthesis takes place. We have previously demonstrated that inactivation of TOM1 results in reduced ToMV multiplication. In the present study, we show that overexpression of TOM1 in tobacco also inhibits ToMV propagation. TOM1 overexpression led to a decreased accumulation of the soluble form of the replication proteins and interfered with the ability of the replication protein to suppress RNA silencing. The reduced accumulation of the soluble replication proteins was also observed in a silencing suppressor-defective ToMV mutant. Based on these results, we propose that RNA silencing suppression is executed by the soluble form of the replication proteins and that efficient ToMV multiplication requires balanced accumulation of the soluble and membrane-bound replication proteins. PMID:18440043

  7. Angiotensin-Converting Enzyme (ACE) 2 Overexpression Ameliorates Glomerular Injury in a Rat Model of Diabetic Nephropathy: A Comparison with ACE Inhibition

    OpenAIRE

    Liu, Chun Xi; Hu, Qin; Yan WANG; Zhang, Wei; Ma, Zhi Yong; Feng, Jin Bo; Wang, Rong; Wang, Xu Ping; Dong, Bo; Gao, Fei; Zhang, Ming Xiang; Zhang, Yun

    2010-01-01

    The reduced expression of angiotensin-converting enzyme (ACE) 2 in the kidneys of animal models and patients with diabetes suggests ACE2 involvement in diabetic nephrology. To explore the renoprotective effects of ACE2 overexpression, ACE inhibition (ACEI) or both on diabetic nephropathy and the potential mechanisms involved, 50 Wistar rats were randomly divided into a normal group that received an injection of sodium citrate buffer and a diabetic model group that received an injection of 60 ...

  8. Overexpression of Carnitine Palmitoyltransferase-1 in Skeletal Muscle Is Sufficient to Enhance Fatty Acid Oxidation and Improve High-Fat Diet–Induced Insulin Resistance

    OpenAIRE

    Bruce, Clinton R.; Hoy, Andrew J.; Turner, Nigel; Watt, Matthew J.; Allen, Tamara L.; Carpenter, Kevin; Cooney, Gregory J.; Febbraio, Mark A; Kraegen, Edward W.

    2009-01-01

    OBJECTIVE—Skeletal muscle insulin resistance is associated with lipid accumulation, but whether insulin resistance is due to reduced or enhanced flux of long-chain fatty acids into the mitochondria is both controversial and unclear. We hypothesized that skeletal muscle–specific overexpression of the muscle isoform of carnitine palmitoyltransferase 1 (CPT1), the enzyme that controls the entry of long-chain fatty acyl CoA into mitochondria, would enhance rates of fatty acid oxidation and improv...

  9. Lactate-Dehydrogenase 5 is overexpressed in non-small cell lung cancer and correlates with the expression of the transketolase-like protein 1

    OpenAIRE

    Stickeler Elmar; Aumann Konrad; Mattern Dominik; Schulte-Uentrop Luzie; Sienel Wulf; Kassem Ahmad; Kayser Gian; Werner Martin; Passlick Bernward; Hausen Axel

    2010-01-01

    Abstract Aims As one of the five Lactate dehydrogenase (LDH) isoenzymes, LDH5 has the highest efficiency to catalyze pyruvate transformation to lactate. LDH5 overexpression in cancer cells induces an upregulated glycolytic metabolism and reduced dependence on the presence of oxygen. Here we analyzed LDH5 protein expression in a well characterized large cohort of primary lung cancers in correlation to clinico-pathological data and its possible impact on patient survival. Methods Primary lung c...

  10. High level extracellular production of a recombinant alkaline catalase in E. coli BL21 under ethanol stress and its application in hydrogen peroxide removal after cotton fabrics bleaching.

    Science.gov (United States)

    Yu, Zhenxiao; Zheng, Hongchen; Zhao, Xingya; Li, Shufang; Xu, Jianyong; Song, Hui

    2016-08-01

    The effects of induction parameters, osmolytes and ethanol stress on the productivity of the recombinant alkaline catalase (KatA) in Escherichia coli BL21 (pET26b-KatA) were investigated. The yield of soluble KatA was significantly enhanced by 2% ethanol stress. And a certain amount of Triton X-100 supplementation could markedly improved extracellular ratio of KatA. A total soluble catalase activity of 78,762U/mL with the extracellular ratio of 92.5% was achieved by fed-batch fermentation in a 10L fermentor, which was the highest yield so far. The purified KatA showed high stability at 50°C and pH 6-10. Application of KatA for elimination of H2O2 after cotton fabrics bleaching led to less consumption of water, steam and electric power by 25%, 12% and 16.7% respectively without productivity and quality losing of cotton fabrics. Thus, the recombinant KatA is a promising candidate for industrial production and applications. PMID:27151682

  11. Effect of the Ascorbic Acid, Pyridoxine and Hydrogen Peroxide Treatments on Germination, Catalase Activity, Protein and Malondialdehyde Content of Three Oil Seeds

    Directory of Open Access Journals (Sweden)

    Aria DOLATABADIAN

    2008-08-01

    Full Text Available Oil seed production has an important role in human nutrition and industry. Success in oil plant cultivation is related to seed production with high viability and rapid germination, because these seeds rapidly loose their viability by fats oxidation. Thus, in this work we studied the effects of ascorbic acid, pyridoxine and hydrogen peroxide solutions on germination quantitative traits, catalase activity, protein and malondialdehyde content of three old oil seeds (sunflower, rape seed and safflower. The results showed that ascorbic acid and pyridoxine stimulated significantly the sunflower and rape seed germination. These vitamins, however, didn't have any effect on safflower germination. Hydrogen peroxide strongly increased safflower germination. Ascorbic acid and pyridoxine decreased catalase activity in sunflower and rape seed, whereas hydrogen peroxide increased it. Ascorbic acid and pyridoxine prevented protein degradation and lipid peroxidation in germinated seeds. Consequently, we understand that ascorbic acid and pyridoxine can increase sunflower and rape seed germination and stimulate rate of growth. Also safflower germination increased due to germination inhibitor oxidation by hydrogen peroxide. In conclusion, this report shows that oil seeds treated with ascorbic acid, pyridoxine and hydrogen peroxide remarkably increase the capacity of germination. We suggest that treatments with such substances can improve the old oil seed germination during storage.

  12. COMPARED ANALYSIS OF CATALASE AND PEROXIDASE ACTIVITY IN CELLULOLYTIC FUNGUS TRICHODERMA REESEI GROWN ON MEDIUM WITH DIFFERENT CONCENTRATIONS OF GRINDED WHEAT AND BARLEY STRAWS

    Directory of Open Access Journals (Sweden)

    Mihaela Cristica

    2010-09-01

    Full Text Available The purpose of this study was to assess the evolution of catalase and peroxidase activity in Trichoderma reesei grown on medium containing grinded wheat and barley straws. Carbon source of cultivation medium - glucose was replaced by various concentrations of grinded wheat and barley straws, finally resulting three experimental variants as follows: V1 = 20 g/l, V2 = 30 g/l, V3 = 40 g/l. ĂŽn addition to these variants a control sample was added in which composition remainded unchanged. The catalase activity was determined by spectrophotometric Sinha method (Artenie et al., 2008 while peroxidase activity was assesed using the o-dianisidine method (Cojocaru, 2009. Enzymatic determinations were carried out at 7 and 14 days from inoculation, in both fungus mycelium and culture liquid. The enzymatic assay showed significant differences between determinations intervals and work variants. Enzyme activity is influenced by the age of fungus and by the different nature of the substrate used.

  13. Effect of Orange (Citrus sinensis Peel Oil on Lipid Peroxidation, Catalase activity and Hepatic Biomarker levels in Blood Plasma of Normo Rats

    Directory of Open Access Journals (Sweden)

    Ochuko L. Erukainure

    2012-07-01

    Full Text Available Dietary antioxidants are considered beneficial because of their potential protective role against oxidative stress, which is involved in the pathogenesis of multiple diseases such as cancer and coronary heart disease. The effect of feeding orange peel oil on lipid peroxidation, catalase and hepatic biomarkers in blood plasma of normo rats was investigated. Beside mouse chow, four diets were designed to contain 50% of energy as carbohydrate, 35% as fat, and 15% as protein, and one that was lipid-free diet which had distilled water substituted for fat. Groups of five rats were each fed one of these diets, while a fifth group was fed pelletized mouse chow. There was no significant difference in the amount of food consumed, though significant weight lost was observed in all groups except soybean oil. Feeding on orange peel oil led to significant (p<0.05 decrease in lipid peroxidation and catalase activities in comparison to soybean oil. Higher AST and lower ALT activities were observed in orange peel oil fed groups. These results suggest the oil from the orange peels possesses antioxidant potentials which could be protective against oxidative stress, thus useful in its treatment and management. However, the elevated levels of hepatic biomarkers pose a threat of hepatotoxicity thus suggesting that it should be consumed or used as a pharmaceutical ingredient at lower concentrations.

  14. Over-expression of COQ10 in Saccharomyces cerevisiae inhibits mitochondrial respiration

    International Nuclear Information System (INIS)

    Research highlights: → COQ10 deletion elicits a defect in mitochondrial respiration correctable by addition of coenzyme Q2, a synthetic diffusible ubiquinone. → The significance that purified Coq10p contains bound Q6 was examined by testing over-expression of Coq10p on respiration. → Inhibition of CoQ function due to Coq10p excess strength our hypothesis of Coq10p function in CoQ delivery. → Respiratory deficiency caused by more Coq10p was specific and restored by Q2 in mitochondria or by Coq8p in cells. → Coq8p over-production on other coq mutants revealed a surprisingly higher stability of other Coq proteins. -- Abstract: COQ10 deletion in Saccharomyces cerevisiae elicits a defect in mitochondrial respiration correctable by addition of coenzyme Q2. Rescue of respiration by Q2 is a characteristic of mutants blocked in coenzyme Q6 synthesis. Unlike Q6 deficient mutants, mitochondria of the coq10 null mutant have wild-type concentrations of Q6. The physiological significance of earlier observations that purified Coq10p contains bound Q6 was examined in the present study by testing the in vivo effect of over-expression of Coq10p on respiration. Mitochondria with elevated levels of Coq10p display reduced respiration in the bc1 span of the electron transport chain, which can be restored with exogenous Q2. This suggests that in vivo binding of Q6 by excess Coq10p reduces the pool of this redox carrier available for its normal function in providing electrons to the bc1 complex. This is confirmed by observing that extra Coq8p relieves the inhibitory effect of excess Coq10p. Coq8p is a putative kinase, and a high-copy suppressor of the coq10 null mutant. As shown here, when over-produced in coq mutants, Coq8p counteracts turnover of Coq3p and Coq4p subunits of the Q-biosynthetic complex. This can account for the observed rescue by COQ8 of the respiratory defect in strains over-producing Coq10p.

  15. Tbx3 represses PTEN and is over-expressed in head and neck squamous cell carcinoma

    International Nuclear Information System (INIS)

    Despite advances in diagnostic and treatment strategies, head and neck squamous cell cancer (HNSCC) constitutes one of the worst cancer types in terms of prognosis. PTEN is one of the tumour suppressors whose expression and/or activity have been found to be reduced in HNSCC, with rather low rates of mutations within the PTEN gene (6-8%). We reasoned that low expression levels of PTEN might be due to a transcriptional repression governed by an oncogene. Tbx2 and Tbx3, both of which are transcriptional repressors, have been found to be amplified or over-expressed in various cancer types. Thus, we hypothesize that Tbx3 may be over expressed in HNSCC and may repress PTEN, thus leading to cancer formation and/or progression. Using immunohistochemistry and quantitative PCR (qPCR), protein and mRNA levels of PTEN and Tbx3 were identified in samples excised from cancerous and adjacent normal tissues from 33 patients who were diagnosed with HNSCC. In addition, HeLa and HEK cell lines were transfected with a Tbx3 expressing plasmid and endogenous PTEN mRNA and protein levels were determined via qPCR and flow cytometry. Transcription assays were performed to demonstrate effects of Tbx3 on PTEN promoter activity. Mann–Whitney, Spearman’s Correlation and Wilcoxon signed-rank tests were used to analyze the data. We demonstrate that in HNSCC samples, Tbx3 mRNA levels are increased with respect to their normal tissue counterparts (p<0.001), whereas PTEN mRNA levels are significantly reduced in cancer tissues. Moreover, Tbx3 protein is also increased in HNSCC tissue sections. Over-expression of Tbx3 in HeLa and HEK cell lines causes reduction in endogenous PTEN mRNA and protein levels. In addition, transcription activity assays reveal that Tbx3 is capable of repressing both the basal and induced promoter activity of PTEN. We show that Tbx3 is up-regulated in tissue samples of HNSCC patients and that Tbx3 represses PTEN transcription. Thus, our data not only reveals a new

  16. Over-expression of COQ10 in Saccharomyces cerevisiae inhibits mitochondrial respiration

    Energy Technology Data Exchange (ETDEWEB)

    Zampol, Mariana A.; Busso, Cleverson; Gomes, Fernando [Departamento de Microbiologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo (Brazil); Ferreira-Junior, Jose Ribamar [Escola de Artes, Ciencias e Humanidades, Universidade de Sao Paulo, Sao Paulo (Brazil); Tzagoloff, Alexander [Department of Biological Sciences, Columbia University, NY (United States); Barros, Mario H., E-mail: mariohb@usp.br [Departamento de Microbiologia, Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo (Brazil)

    2010-11-05

    Research highlights: {yields} COQ10 deletion elicits a defect in mitochondrial respiration correctable by addition of coenzyme Q{sub 2}, a synthetic diffusible ubiquinone. {yields} The significance that purified Coq10p contains bound Q{sub 6} was examined by testing over-expression of Coq10p on respiration. {yields} Inhibition of CoQ function due to Coq10p excess strength our hypothesis of Coq10p function in CoQ delivery. {yields} Respiratory deficiency caused by more Coq10p was specific and restored by Q{sub 2} in mitochondria or by Coq8p in cells. {yields} Coq8p over-production on other coq mutants revealed a surprisingly higher stability of other Coq proteins. -- Abstract: COQ10 deletion in Saccharomyces cerevisiae elicits a defect in mitochondrial respiration correctable by addition of coenzyme Q{sub 2}. Rescue of respiration by Q{sub 2} is a characteristic of mutants blocked in coenzyme Q{sub 6} synthesis. Unlike Q{sub 6} deficient mutants, mitochondria of the coq10 null mutant have wild-type concentrations of Q{sub 6}. The physiological significance of earlier observations that purified Coq10p contains bound Q{sub 6} was examined in the present study by testing the in vivo effect of over-expression of Coq10p on respiration. Mitochondria with elevated levels of Coq10p display reduced respiration in the bc1 span of the electron transport chain, which can be restored with exogenous Q{sub 2}. This suggests that in vivo binding of Q{sub 6} by excess Coq10p reduces the pool of this redox carrier available for its normal function in providing electrons to the bc1 complex. This is confirmed by observing that extra Coq8p relieves the inhibitory effect of excess Coq10p. Coq8p is a putative kinase, and a high-copy suppressor of the coq10 null mutant. As shown here, when over-produced in coq mutants, Coq8p counteracts turnover of Coq3p and Coq4p subunits of the Q-biosynthetic complex. This can account for the observed rescue by COQ8 of the respiratory defect in strains

  17. Isolation and properties of fibroblast mutants overexpressing an altered Na+/H+ antiporter

    International Nuclear Information System (INIS)

    A new method based on the toxicity of low intracellular pH (pH/sub i/) was developed to isolate fibroblasts variants overexpressing Na+/H+ antiport activity. Chinese hamster lung fibroblasts (CCL39) were incubated for 60 min in medium containing 50 mM NH4Cl. Removal of external NH+4 induced in a rapid and lethal intracellular acidification when the Na+/H+ antiporter was inhibited during the 60 min of the pH/sub i/ recovery phase. The inhibition was provoked either by adding 5-(N-methyl, N-propyl)amiloride (MPA, LD50= 0.3 μM) or by reducing external [Na+] (LD50 = 25 mM). Progressively increasing the MPA concentration during the acid-load selection led to the isolation of two stable variants: AR40 and AR300, resistant, respectively, to 40 and 300 μM MPA. In response to an acid-load, these variants display a much higher rate of pH/sub i/ recovery due to an overexpression of Na+/H+ antiport activity. In addition, AR40 and AR300 have an altered Na+/H+ antiporter. Alternatively reducing Na+ concentration of the pH/sub i/ recovery saline medium in a stepwise manner led to the selection of another class of variants (DD8 and DD12) also characterized by an altered Na+/H+ antiporter and an increased expression level. The 10-fold increased rate of amiloride-sensitive Na+ influx of DD12 is accounted for by a 4-fold increase in V/sub max/ and a 2.5-fold increase in affinity for Na+ or Li+ at the external site. In conclusion, the genetic approach presented here: (i) provides a general and specific method for selecting variants of the Na+/H+ antiporter with increased expression levels and/or with structural alterations and (ii) demonstrates that the external Na+-and amiloride-binding sites are not identical, since they can be genetically altered independently of each other

  18. Clinical significance of Phosphatidyl Inositol Synthase overexpression in oral cancer

    International Nuclear Information System (INIS)

    We reported increased levels of Phosphatidyl Inositol synthase (PI synthase), (enzyme that catalyses phosphatidyl inositol (PI) synthesis-implicated in intracellular signaling and regulation of cell growth) in smokeless tobacco (ST) exposed oral cell cultures by differential display. This study determined the clinical significance of PI synthase overexpression in oral squamous cell carcinoma (OSCC) and premalignant lesions (leukoplakia), and identified the downstream signaling proteins in PI synthase pathway that are perturbed by smokeless tobacco (ST) exposure. Tissue microarray (TMA) Immunohistochemistry, Western blotting, Confocal laser scan microscopy, RT-PCR were performed to define the expression of PI synthase in clinical samples and in oral cell culture systems. Significant increase in PI synthase immunoreactivity was observed in premalignant lesions and OSCCs as compared to oral normal tissues (p = 0.000). Further, PI synthase expression was significantly associated with de-differentiation of OSCCs, (p = 0.005) and tobacco consumption (p = 0.03, OR = 9.0). Exposure of oral cell systems to smokeless tobacco (ST) in vitro confirmed increase in PI synthase, Phosphatidylinositol 3-kinase (PI3K) and cyclin D1 levels. Collectively, increased PI synthase expression was found to be an early event in oral cancer and a target for smokeless tobacco

  19. Overexpression and topology of bacterial oligosaccharyltransferase PglB

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lei [National Glycoengineering Research Center and The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Shandong 250100 (China); Departments of Biochemistry and Chemistry, The Ohio State University, Columbus, OH 43210 (United States); Woodward, Robert [Departments of Biochemistry and Chemistry, The Ohio State University, Columbus, OH 43210 (United States); Ding, Yan; Liu, Xian-wei [National Glycoengineering Research Center and The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Shandong 250100 (China); Yi, Wen; Bhatt, Veer S. [Departments of Biochemistry and Chemistry, The Ohio State University, Columbus, OH 43210 (United States); Chen, Min [National Glycoengineering Research Center and The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Shandong 250100 (China); Zhang, Lian-wen [College of Pharmacy, Nankai University, Tianjin 300071 (China); Wang, Peng George, E-mail: wang.892@osu.edu [National Glycoengineering Research Center and The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Shandong 250100 (China); Departments of Biochemistry and Chemistry, The Ohio State University, Columbus, OH 43210 (United States)

    2010-04-16

    Campylobacter jejuni contains a post-translational N-glycosylation system in which a STT3 homologue, PglB, functions as the oligosaccharyltransferase. Herein, we established a method for obtaining relatively large quantities of homogenous PglB proteins. PglB was overexpressed in Escherichia coli C43(DE3) at a level of 1 mg/L cell cultures. The activity of purified PglB was verified using a chemically synthesized sugar donor: N-acetylgalactosamine-diphospho-undecaprenyl (GalNAc-PP-Und) and a synthesized peptide acceptor. The result confirms that PglB is solely responsible for the oligosaccharyltransferase activity and complements the finding that PglB exhibits relaxed sugar substrate specificity. In addition, we performed the topology mapping of PglB using the PhoA/LacZ fusion method. The topological model shows that PglB possesses 11 transmembrane segments and two relatively large periplasmic regions other than the C-terminal domain, which is consistent with the proposal of the common N{sub cyt}-C{sub peri} topology with 11 transmembrane segments for the STT3 family proteins.

  20. Caveolin-1 overexpression in benign and malignant salivary gland tumors.

    Science.gov (United States)

    Jaafari-Ashkavandi, Zohreh; Ashraf, Mohammad Javad; Nazhvani, Ali Dehghani; Azizi, Zahra

    2016-02-01

    Caveolin-1, a tyrosine-phosphorylated protein, is supposed to have different regulatory roles as promoter or suppressor in many human cancers. However, no published study concerned its expression in benign and malignant salivary gland tumors. The aim of this study was to evaluate and compare the expression of Cav-1 in the most common benign and malignant salivary gland tumors and evaluate its correlation with proliferation activity. In this cross-sectional retrospective study, immunohistochemical expression of caveolin-1 and Ki67 were evaluated in 49 samples, including 11 normal salivary glands, 15 cases of pleomorphic adenoma (PA), 13 adenoid cystic carcinomas (AdCC), and 10 mucoepidermoid carcinomas (MEC). The expression of Cav-1 was seen in 18 % of normal salivary glands and 85 % of tumors. The immunoreaction in the tumors was significantly higher than normal tissues (P = 0.001), but the difference between benign and malignant tumors was not significant (P = 0.07). Expression of Cav-1 was correlated with Ki67 labeling index in PAs, but not in malignant tumors. Cav-1 expression was not in association with tumor size and stage. Overexpression of Cav-1 was found in salivary gland tumors in comparison with normal tissues, but no significant difference was observed between benign and malignant tumors. Cav-1 was inversely correlated with proliferation in PA. Therefore, this marker may participate in tumorigenesis of salivary gland tumors and may be a potential biomarker for cancer treatments. PMID:26323261