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Sample records for n-acetylcysteine-mediated catalase upregulation

  1. A rapid and transient ROS generation by cadmium triggers apoptosis via caspase-dependent pathway in HepG2 cells and this is inhibited through N-acetylcysteine-mediated catalase upregulation

    SciTech Connect

    Oh, Seon-Hee; Lim, Sung-Chul . E-mail: sclim@chosun.ac.kr

    2006-05-01

    Although reactive oxygen species (ROS) have been implicated in cadmium (Cd)-induced hepatotoxicity, the role of ROS in this pathway remains unclear. Therefore, we attempted to determine the molecular mechanisms relevant to Cd-induced cell death in HepG2 cells. Cd was found to induce apoptosis in the HepG2 cells in a time- and dose-dependent fashion, as confirmed by DNA fragmentation analysis and TUNEL staining. In the early stages, both rapid and transient ROS generation triggered apoptosis via Fas activation and subsequent caspase-8-dependent Bid cleavage, as well as by calpain-mediated mitochondrial Bax cleavage. The timing of Bid activation was coincided with the timing at which the mitochondrial transmembrane potential (MMP) collapsed as well as the cytochrome c (Cyt c) released into the cytosol. Furthermore, mitochondrial permeability transition (MPT) pore inhibitors, such as cyclosporin A (CsA) and bongkrekic acid (BA), did not block Cd-induced ROS generation, MMP collapse and Cyt c release. N-acetylcysteine (NAC) pretreatment resulted in the complete inhibition of the Cd-induced apoptosis via catalase upregulation and subsequent Fas downregulation. NAC treatment also completely blocked the Cd-induced intracellular ROS generation, MMP collapse and Cyt c release, indicating that Cd-induced mitochondrial dysfunction may be regulated indirectly by ROS-mediated signaling pathway. Taken together, a rapid and transient ROS generation by Cd triggers apoptosis via caspase-dependent pathway and subsequent mitochondrial pathway. NAC inhibits Cd-induced apoptosis through the blocking of ROS generation as well as the catalase upregulation.

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

    PubMed Central

    Whittaker, James W.

    2012-01-01

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

  3. Radiation immobilization of catalase and its application

    NASA Astrophysics Data System (ADS)

    Guanghui, Wang; Hongfei, Ha; Xia, Wang; Jilan, Wu

    Catalase was immobilized by chemical method on porous polyacrylamide particles which produced through radiation polymerization of acrylamide monomer at low temperature (-78°C). Activity of immobilized catalase was enhanced distinctly by joining a chemical "arm" to the support. The method of recovery of catalase activity on immobilized polymer was found by soaking it in certain buffer. The treatment of H 2O 2 both in aqueous solution and alcoholic solution by using the immobilized catalase was performed.

  4. Sirt1 protects against oxidative stress-induced renal tubular cell apoptosis by the bidirectional regulation of catalase expression

    SciTech Connect

    Hasegawa, Kazuhiro; Wakino, Shu Yoshioka, Kyoko; Tatematsu, Satoru; Hara, Yoshikazu; Minakuchi, Hitoshi; Washida, Naoki; Tokuyama, Hirobumi; Hayashi, Koichi; Itoh, Hiroshi

    2008-07-18

    NAD{sup +}-dependent protein deacetylase Sirt1 regulates cellular apoptosis. We examined the role of Sirt1 in renal tubular cell apoptosis by using HK-2 cells, proximal tubular cell lines with or without reactive oxygen species (ROS), H{sub 2}O{sub 2}. Without any ROS, Sirt1 inhibitors enhanced apoptosis and the expression of ROS scavenger, catalase, and Sirt1 overexpression downregulated catalase. When apoptosis was induced with H{sub 2}O{sub 2}, Sirt1 was upregulated with the concomitant increase in catalase expression. Sirt1 overexpression rescued H{sub 2}O{sub 2}-induced apoptosis through the upregulation of catalase. H{sub 2}O{sub 2} induced the nuclear accumulation of forkhead transcription factor, FoxO3a and the gene silencing of FoxO3a enhanced H{sub 2}O{sub 2}-induced apoptosis. In conclusion, endogenous Sirt1 maintains cell survival by regulating catalase expression and by preventing the depletion of ROS required for cell survival. In contrast, excess ROS upregulates Sirt1, which activates FoxO3a and catalase leading to rescuing apoptosis. Thus, Sirt1 constitutes a determinant of renal tubular cell apoptosis by regulating cellular ROS levels.

  5. [Immobilized catalase in water purification systems].

    PubMed

    Nazarov, N M; Bezborodov, A M; Solomon, Z G; Biber, B L; Malykh, E Iu

    1998-01-01

    The results of studies on producing the biocatalyst based on catalase immobilized in the fibers from triacetate are presented. The catalase producer is Penicillium fungus. Catalase was produced by precipitation with the use of ethyl alcohol from the cultural fluid with separate and unseparate mycelium. The highest activity of catalase in the cultural fluid is seen on the nutrient medium containing 4% of carbon source. For immobilization the water solution of enzyme was concentrated in the vacuum-rotor evaporator at temperature of 25 degrees C. The enzyme was included in the structure of fibers during the process of their formation. Of the fiber-producing polymers (cellulose triacetate, chlorine, polysulphone) the most enzymatic activity has the catalase-containing fibers derived from the cellulose triacetate, in this case, the fine fibers of biocatalyst have the higher specific activity. It is established that the fibers obtained by using catalase of microbiological origin possess high stability and their activity does not practically change in the aqueous environment. The unpurified catalase is one and a half higher than at purified catalase. Under laboratory conditions there turned out the experimental batches of fibers and there conducted their endurance tests. Catalase included in cellulase triacetate has effectively functioned during a period of 2 years purifying the distilled water containing 50 mg/l of hydrogen peroxide. PMID:9858984

  6. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in...

  7. 7 CFR 58.432 - Catalase.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Quality Specifications for Raw Material § 58.432 Catalase. The catalase preparation shall be a stable, buffered solution, neutral in...

  8. Catalases Induction in High Virulence Pinewood Nematode Bursaphelenchus xylophilus under Hydrogen Peroxide-Induced Stress.

    PubMed

    Vicente, Cláudia S L; Ikuyo, Yoriko; Shinya, Ryoji; Mota, Manuel; Hasegawa, Koichi

    2015-01-01

    Considered an EPPO A2 quarantine pest, Bursaphelenchus xylophilus is the causal agent of the pine wilt disease and the most devastating plant parasitic nematode attacking coniferous trees in the world. In the early stages of invasion, this nematode has to manage host defence mechanisms, such as strong oxidative stress. Only successful, virulent nematodes are able to tolerate the basal plant defences, and furthermore migrate and proliferate inside of the host tree. In this work, our main objective was to understand to what extent B. xylophilus catalases are involved in their tolerance to oxidative stress and virulence, using as oxidant agent the reactive oxygen species hydrogen peroxide (H2O2). After 24 hours of exposure, high virulence isolates of B. xylophilus could withstand higher H2O2 concentrations in comparison with low virulence B. xylophilus and B. mucronatus, corroborating our observation of Bxy-ctl-1 and Bxy-ctl-2 catalase up-regulation under the same experimental conditions. Both catalases are expressed throughout the nematode intestine. In addition, transgenic strains of Caenorhabditis elegans overexpressing B. xylophilus catalases were constructed and evaluated for survival under similar conditions as previously. Our results suggest that catalases of high virulence B. xylophilus were crucial for nematode survival under prolonged exposure to in vitro oxidative stress, highlighting their adaptive response, which could contribute to their success in host conditions. PMID:25894519

  9. Catalases Induction in High Virulence Pinewood Nematode Bursaphelenchus xylophilus under Hydrogen Peroxide-Induced Stress

    PubMed Central

    Vicente, Cláudia S. L.; Ikuyo, Yoriko; Shinya, Ryoji; Mota, Manuel; Hasegawa, Koichi

    2015-01-01

    Considered an EPPO A2 quarantine pest, Bursaphelenchus xylophilus is the causal agent of the pine wilt disease and the most devastating plant parasitic nematode attacking coniferous trees in the world. In the early stages of invasion, this nematode has to manage host defence mechanisms, such as strong oxidative stress. Only successful, virulent nematodes are able to tolerate the basal plant defences, and furthermore migrate and proliferate inside of the host tree. In this work, our main objective was to understand to what extent B. xylophilus catalases are involved in their tolerance to oxidative stress and virulence, using as oxidant agent the reactive oxygen species hydrogen peroxide (H2O2). After 24 hours of exposure, high virulence isolates of B. xylophilus could withstand higher H2O2 concentrations in comparison with low virulence B. xylophilus and B. mucronatus, corroborating our observation of Bxy-ctl-1 and Bxy-ctl-2 catalase up-regulation under the same experimental conditions. Both catalases are expressed throughout the nematode intestine. In addition, transgenic strains of Caenorhabditis elegans overexpressing B. xylophilus catalases were constructed and evaluated for survival under similar conditions as previously. Our results suggest that catalases of high virulence B. xylophilus were crucial for nematode survival under prolonged exposure to in vitro oxidative stress, highlighting their adaptive response, which could contribute to their success in host conditions. PMID:25894519

  10. Gold nanoparticles and/or N-acetylcysteine mediate carrageenan-induced inflammation and oxidative stress in a concentration-dependent manner.

    PubMed

    Paula, Marcos M S; Petronilho, Fabricia; Vuolo, Francieli; Ferreira, Gabriela K; De Costa, Leandro; Santos, Giulia P; Effting, Pauline S; Dal-Pizzol, Felipe; Dal-Bó, Alexandre G; Frizon, Tiago E; Silveira, Paulo C L; Pinho, Ricardo A

    2015-10-01

    We report the effect of gold nanoparticles (AuNP) in an acute inflammation model induced by carrageenan (CG) and compared this effect with those induced by the antioxidant N-acetylcysteine (NAC) alone and by the synergistic effect of NAC and AuNP together. Male Wistar rats received saline or saline containing CG administered into the pleural cavity, and some rats also received NAC (20 mg/kg) subcutaneously and/or AuNP administered into the pleural cavity immediately after surgery. Four hours later, the rats were sacrificed and pleural exudates obtained for evaluation of cytokine levels and myeloperoxidase activities. Oxidative stress parameters were also evaluated in the lungs. The results demonstrated that the inflammatory process caused by the administration of CG into the pleural cavity resulted in a substantial increase in the levels of tumor necrosis factor-?, interleukin-1?, and myeloperoxidase and a reduction in interleukin-10 levels. These levels seem to be reversed after different treatments in animals. Antioxidant enzymes exhibited positive responses after treatment of NAC?+?AuNP, and all treatments were effective at reducing lipid peroxidation and oxidation of thiol groups induced by CG. These findings suggest that small compounds, such as NAC plus AuNP, may be useful in the treatment of conditions associated with local inflammation. PMID:25917538

  11. Discovery of Catalases in Members of the Chlamydiales Order

    PubMed Central

    Rusconi, Brigida

    2013-01-01

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

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

    E-print Network

    Simha, Rahul

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

  13. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase...

  14. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase...

  15. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase...

  16. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase...

  17. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase...

  18. Probing the binding of flavonoids to catalase by molecular spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhu, Jingfeng; Zhang, Xia; Li, Daojin; Jin, Jing

    2007-10-01

    The binding of flavonoids (quercetin and myricetin) to catalase was investigated by fluorescence and circular dichroism (CD) techniques under physiological conditions. The binding parameters and binding mode between flavonoids and catalase were determined, and the results of synchronous fluorescence spectra and CD indicated a conformational change of catalase with addition of flavonoids. The effect of both Cu 2+ and vitamin C on the binding constant of flavonoid-catalase was also examined. The experiment data show that the difference of the structure characteristics of quercetin and myricetin has a significant effect on their binding affinity for catalase.

  19. Molecular Characterization of a Catalase from Hydra vulgaris

    PubMed Central

    Dash, Bhagirathi; Phillips, Timothy D.

    2012-01-01

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

  20. Hydrogen peroxide production regulates the mitochondrial function in insulin resistant muscle cells: effect of catalase overexpression.

    PubMed

    Barbosa, Marina R; Sampaio, Igor H; Teodoro, Bruno G; Sousa, Thais A; Zoppi, Claudio C; Queiroz, André L; Passos, Madla A; Alberici, Luciane C; Teixeira, Felipe R; Manfiolli, Adriana O; Batista, Thiago M; Cappelli, Ana Paula Gameiro; Reis, Rosana I; Frasson, Danúbia; Kettelhut, Isis C; Parreiras-e-Silva, Lucas T; Costa-Neto, Claudio M; Carneiro, Everardo M; Curi, Rui; Silveira, Leonardo R

    2013-10-01

    The mitochondrial redox state plays a central role in the link between mitochondrial overloading and insulin resistance. However, the mechanism by which the ROS induce insulin resistance in skeletal muscle cells is not completely understood. We examined the association between mitochondrial function and H2O2 production in insulin resistant cells. Our hypothesis is that the low mitochondrial oxygen consumption leads to elevated ROS production by a mechanism associated with reduced PGC1? transcription and low content of phosphorylated CREB. The cells were transfected with either the encoded sequence for catalase overexpression or the specific siRNA for catalase inhibition. After transfection, myotubes were incubated with palmitic acid (500?M) and the insulin response, as well as mitochondrial function and fatty acid metabolism, was determined. The low mitochondrial oxygen consumption led to elevated ROS production by a mechanism associated with ?-oxidation of fatty acids. Rotenone was observed to reduce the ratio of ROS production. The elevated H2O2 production markedly decreased the PGC1? transcription, an effect that was accompanied by a reduced phosphorylation of Akt and CREB. The catalase transfection prevented the reduction in the phosphorylated level of Akt and upregulated the levels of phosphorylated CREB. The mitochondrial function was elevated and H2O2 production reduced, thus increasing the insulin sensitivity. The catalase overexpression improved mitochondrial respiration protecting the cells from fatty acid-induced, insulin resistance. This effect indicates that control of hydrogen peroxide production regulates the mitochondrial respiration preventing the insulin resistance in skeletal muscle cells by a mechanism associated with CREB phosphorylation and ?-oxidation of fatty acids. PMID:23643711

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

    SciTech Connect

    Mori, Yoki; Murakami, Sumika; Sagae, Toshiyuki

    1996-02-09

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because H{sub 2}O{sub 2} is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase by DEP was observed only in the presence of anions such as Cl{sup {minus}}, Br{sup {minus}}, or thiocyanate. Other anions, such as CH{sub 3}COO{sup {minus}} or SO{sub 4}{sup {minus}}, and cations such as K{sup +}, Na{sup +}, Mg{sup 2+}, or Fe{sup 2+}, did not affect the activity of catalase, even in the presence of DEP extract. Catalase from guinea pig alveolar cells and catalase from red blood cells were also inhibited by DEP extracts, as was catalase from bovine liver. These results suggest that DEP taken up in the lung and located on alveolar spaces might cause cell injury by inhibiting the activity of catalase in epithelial lining fluid, enhancing the toxicity of H{sub 2}O{sub 2} generated from cells in addition to that of O{sub 2}{sup {minus}} generated by the chemical reaction of DEP with oxygen. 10 refs., 6 figs.

  2. Catalase-positive microbial detection by using different ultrasonic parameters

    NASA Astrophysics Data System (ADS)

    Shukla, S. K.; Durán, C.; Elvira, L.

    2012-12-01

    A method for rapid detection of catalase enzyme activity using ultrasonic parameters is presented in this work. It is based on the detection of the hydrolysis of hydrogen peroxide molecule into water and oxygen induced by the enzyme catalase. A special medium was made to amplify changes produced by catalase enzyme during the hydrolysis process. Enzymatic process can be monitored by means of ultrasonic parameters such as wave amplitude, time of flight (TOF), and backscattering measurements which are sensitive to oxygen bubble production. It is shown that catalase activity of the order of 10-3unit/ml can be detected using different ultrasonic parameters. The sensitivity provided by them is discussed.

  3. The effect of alcohol and hydrogen peroxide on liver hepcidin gene expression in mice lacking antioxidant enzymes, glutathione peroxidase-1 or catalase.

    PubMed

    Harrison-Findik, Duygu Dee; Lu, Sizhao

    2015-01-01

    This study investigates the regulation of hepcidin, the key iron-regulatory molecule, by alcohol and hydrogen peroxide (H2O2) in glutathione peroxidase-1 (gpx-1(-/-)) and catalase (catalase(-/-)) knockout mice. For alcohol studies, 10% ethanol was administered in the drinking water for 7 days. Gpx-1(-/-) displayed significantly higher hepatic H2O2 levels than catalase(-/-) compared to wild-type mice, as measured by 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA). The basal level of liver hepcidin expression was attenuated in gpx-1(-/-) mice. Alcohol increased H2O2 production in catalase(-/-) and wild-type, but not gpx-1(-/-), mice. Hepcidin expression was inhibited in alcohol-fed catalase(-/-) and wild-type mice. In contrast, alcohol elevated hepcidin expression in gpx-1(-/-) mice. Gpx-1(-/-) mice also displayed higher level of basal liver CHOP protein expression than catalase(-/-) mice. Alcohol induced CHOP and to a lesser extent GRP78/BiP expression, but not XBP1 splicing or binding of CREBH to hepcidin gene promoter, in gpx-1(-/-) mice. The up-regulation of hepatic ATF4 mRNA levels, which was observed in gpx-1(-/-) mice, was attenuated by alcohol. In conclusion, our findings strongly suggest that H2O2 inhibits hepcidin expression in vivo. Synergistic induction of CHOP by alcohol and H2O2, in the absence of gpx-1, stimulates liver hepcidin gene expression by ER stress independent of CREBH. PMID:25955433

  4. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... fermentation process may be safely used in destroying and removing hydrogen peroxide used in the manufacture of... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived...

  5. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... fermentation process may be safely used in destroying and removing hydrogen peroxide used in the manufacture of... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived...

  6. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fermentation process may be safely used in destroying and removing hydrogen peroxide used in the manufacture of... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Catalase derived from Micrococcus lysodeikticus... FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.135 Catalase derived...

  7. IS CATALASE ACTIVITY ASSOCIATED WITH MAIZE RESISTANCE TO ASPERGILLUS FLAVUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catalase activity was measured in various cob tissues during maize ear development because of its role in maintaining reactive oxygen homeostasis during biotic and abiotic stress. Catalase activity was determined in immature and mature embryos, pericarp, and rachis tissues of maize lines that are re...

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

    PubMed Central

    2011-01-01

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

  9. Regulation of catalase expression in healthy and cancerous cells.

    PubMed

    Glorieux, Christophe; Zamocky, Marcel; Sandoval, Juan Marcelo; Verrax, Julien; Calderon, Pedro Buc

    2015-10-01

    Catalase is an important antioxidant enzyme that dismutates hydrogen peroxide into water and molecular oxygen. The catalase gene has all the characteristics of a housekeeping gene (no TATA box, no initiator element sequence, high GC content in promoter) and a core promoter that is highly conserved among species. We demonstrate in this review that within this core promoter, the presence of DNA binding sites for transcription factors, such as NF-Y and Sp1, plays an essential role in the positive regulation of catalase expression. Additional transcription factors, such as FoxO3a, are also involved in this regulatory process. There is strong evidence that the protein Akt/PKB in the PI3K signaling pathway plays a major role in the expression of catalase by modulating the activity of FoxO3a. Over the past decade, other transcription factors (PPAR?, Oct-1, etc.), as well as genetic, epigenetic, and posttranscriptional processes, have emerged as crucial contributors to the regulation of catalase expression. Altered expression levels of catalase have been reported in cancer tissues compared to their normal counterparts. Deciphering the molecular mechanisms that regulate catalase expression could, therefore, be of crucial importance for the future development of pro-oxidant cancer chemotherapy. PMID:26117330

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

    PubMed

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

    1984-10-01

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

  11. A Laboratory Experiment of the Purification of Catalase.

    ERIC Educational Resources Information Center

    Busquets, Montserrat; Franco, Rafael

    1986-01-01

    Describes a simple method for purifying catalase for the study of proteins. Procedures are systematically and diagramatically presented. Also identifies polyacrylamide gel electrophoresis, kinetic studies, and apparent molecular weight determination as possible techniques to be used in studying proteins. (ML)

  12. Increased microglial catalase activity in multiple sclerosis grey matter.

    PubMed

    Gray, Elizabeth; Kemp, Kevin; Hares, Kelly; Redondo, Julianna; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2014-04-22

    Chronic demyelination, on-going inflammation, axonal loss and grey matter neuronal injury are likely pathological processes that contribute to disease progression in multiple sclerosis (MS). Although the precise contribution of each process and their aetiological substrates is not fully known, recent evidence has implicated oxidative damage as a major cause of tissue injury in MS. The degree of tissue injury caused by oxidative molecules, such as reactive oxygen species (ROS), is balanced by endogenous anti-oxidant enzymes which detoxify ROS. Understanding endogenous mechanisms which protect the brain against oxidative injury in MS is important, since enhancing anti-oxidant responses is a major therapeutic strategy for preventing irreversible tissue injury in the disease. Our aims were to determine expression and activity levels of the hydrogen peroxide-reducing enzyme catalase in MS grey matter (GM). In MS GM, a catalase enzyme activity was elevated compared to control GM. We measured catalase protein expression by immune dot-blotting and catalase mRNA by a real-time polymerase chain reaction (RT-PCR). Protein analysis studies showed a strong positive correlation between catalase and microglial marker IBA-1 in MS GM. In addition, calibration of catalase mRNA level with reference to the microglial-specific transcript AIF-1 revealed an increase in this transcript in MS. This was reflected by the extent of HLA-DR immunolabeling in MS GM which was significantly elevated compared to control GM. Collectively, these observations provide evidence that microglial catalase activity is elevated in MS grey matter and may be an important endogenous anti-oxidant defence mechanism in MS. PMID:24602691

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

    PubMed

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

    2008-09-01

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

  14. The Catalase C-262T Gene Polymorphism and Cancer Risk

    PubMed Central

    Shen, Yongchun; Li, Diandian; Tian, Panwen; Shen, Konglong; Zhu, Jing; Feng, Mei; Wan, Chun; Yang, Ting; Chen, Lei; Wen, Fuqiang

    2015-01-01

    Abstract Many studies suggest that catalase C-262T gene polymorphism is associated with cancer risk, but with inconsistent results. This study aimed to summarize the overall association between catalase C-262T polymorphism and cancer risk. Literature search was performed in PubMed, Embase, and other databases, studies regarding the association between catalase C-262T polymorphism and cancer risk were identified, and data were retrieved and analyzed by using Review Manager 5.0.24 and STATA 12.0. A total of 18 publications with 22 case–control studies, including 9777 cancer patients and 12,223 controls, met the inclusion criteria. Meta-analysis results showed significant association between catalase C-262 T polymorphism and cancer risk (TT vs CT?+?CC: odds ratio [OR]?=?1.17, 95% confidence interval [CI]?=?1.03–1.31, P?=?0.01). Subgroup analyses stratified by cancer types suggested the catalase C-262T polymorphism was significantly associated with an increased prostate cancer risk (TT vs CT?+?CC: OR?=?1.61, 95% CI?=?1.17–2.22, P?=?0.004); for subgroup analyses stratified by ethnicity, no associations between this polymorphism and Asians or whites were identified (CT?+?TT vs CC: OR?=?1.11, 95% CI?=?0.98–1.26, P?=?0.09 for whites; OR?=?1.19, 95% CI?=?0.78–1.80, P?=?0.42 for Asians). In summary, the catalase C-262T polymorphism may be a risk factor for cancer with cancer type-specific effects. Further studies should be performed to confirm these findings. PMID:25837760

  15. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Catalase derived from Micrococcus lysodeikticus. 173.135 Section 173.135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme...

  16. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of...purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1...requirements and additional requirements for enzyme preparations in the Food...

  17. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of...purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1...requirements and additional requirements for enzyme preparations in the Food...

  18. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of...purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1...requirements and additional requirements for enzyme preparations in the Food...

  19. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of...purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1...requirements and additional requirements for enzyme preparations in the Food...

  20. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of...purified liquid or powder. Its characterizing enzyme activity is catalase (EC 1.11.1...requirements and additional requirements for enzyme preparations in the Food...

  1. 21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Catalase derived from Micrococcus lysodeikticus. 173.135 Section 173.135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION...

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    Biocatalytic propulsion is expected to play an important role in the future of micromotors as it might drastically increase the number of available fuelling reactions. However, most of the enzyme-propelled micromotors so far reported still rely on the degradation of peroxide by catalase, in spite of being vulnerable to relatively high peroxide concentrations. To overcome this limitation, herein we present a strategy to encapsulate the catalase and to graft the resulting enzyme capsules on motor particles. Significant improvement of the stability in the presence of peroxide and other aggressive agents has been observed.Biocatalytic propulsion is expected to play an important role in the future of micromotors as it might drastically increase the number of available fuelling reactions. However, most of the enzyme-propelled micromotors so far reported still rely on the degradation of peroxide by catalase, in spite of being vulnerable to relatively high peroxide concentrations. To overcome this limitation, herein we present a strategy to encapsulate the catalase and to graft the resulting enzyme capsules on motor particles. Significant improvement of the stability in the presence of peroxide and other aggressive agents has been observed. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr02459a

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

    E-print Network

    Nishiguchi, Michele

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

  4. Altered methanol embryopathies in embryo culture with mutant catalase-deficient mice and transgenic mice expressing human catalase

    SciTech Connect

    Miller, Lutfiya; Wells, Peter G.

    2011-04-01

    The mechanisms underlying the teratogenicity of methanol (MeOH) in rodents, unlike its acute toxicity in humans, are unclear, but may involve reactive oxygen species (ROS). Embryonic catalase, although expressed at about 5% of maternal activity, may protect the embryo by detoxifying ROS. This hypothesis was investigated in whole embryo culture to remove confounding maternal factors, including metabolism of MeOH by maternal catalase. C57BL/6 (C57) mouse embryos expressing human catalase (hCat) or their wild-type (C57 WT) controls, and C3Ga.Cg-Catb/J 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 4 mg/ml MeOH or vehicle, and evaluated for functional and morphological changes. hCat and C57 WT vehicle-exposed embryos developed normally. MeOH was embryopathic in C57 WT embryos, evidenced by decreases in anterior neuropore closure, somites developed and turning, whereas hCat embryos were protected. Vehicle-exposed aCat mouse embryos had lower yolk sac diameters compared to C3H WT controls, suggesting that endogenous ROS are embryopathic. MeOH was more embryopathic in aCat embryos than WT controls, with reduced anterior neuropore closure and head length only in catalase-deficient embryos. These data suggest that ROS may be involved in the embryopathic mechanism of methanol, and that embryonic catalase activity may be a determinant of teratological risk.

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

    PubMed

    Miller-Pinsler, Lutfiya; Wells, Peter G

    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(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 24h to 2 or 4mg/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 50kU/kg PEG-catalase (PEG-cat) 8h 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. PMID:26074427

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

    PubMed Central

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

    1991-01-01

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

  7. Progeric effects of catalase inactivation in human cells

    SciTech Connect

    Koepke, Jay I.; Wood, Christopher S.; Terlecky, Laura J.; Walton, Paul A.; Terlecky, Stanley R.

    2008-10-01

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

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

    PubMed Central

    Yao, Chunxiang; Behring, Jessica B.; Shao, Di; Sverdlov, Aaron L.; Whelan, Stephen A.; Elezaby, Aly; Yin, Xiaoyan; Siwik, Deborah A.; Seta, Francesca; Costello, Catherine E.; Cohen, Richard A.; Matsui, Reiko; Colucci, Wilson S.; McComb, Mark E.; Bachschmid, Markus M.

    2015-01-01

    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. PMID:26642319

  9. Catalase eliminates reactive oxygen species and influences the intestinal microbiota of shrimp.

    PubMed

    Yang, Hui-Ting; Yang, Ming-Chong; Sun, Jie-Jie; Guo, Fang; Lan, Jiang-Feng; Wang, Xian-Wei; Zhao, Xiao-Fan; Wang, Jin-Xing

    2015-11-01

    Intestinal innate immune response is an important defense mechanism of animals and humans against external pathogens. The mechanism of microbiota homeostasis in host intestines has been well studied in mammals and Drosophila. The reactive oxygen species (ROS) and antimicrobial peptides have been reported to play important roles in homeostasis. However, how to maintain the microbiota homeostasis in crustacean intestine needs to be elucidated. In this study, we identified a novel catalase (MjCAT) involved in ROS elimination in kuruma shrimp, Marsupenaeus japonicus. MjCAT mRNA was widely distributed in hemocytes, heart, hepatopancreas, gills, stomach, and intestine. After the shrimp were challenged with pathogenic bacteria via oral infection, the expression level of MjCAT was upregulated, and the enzyme activity was increased in the intestine. ROS level was also increased in the intestine at early time after oral infection and recovered rapidly. When MjCAT was knocked down by RNA interference (RNAi), high ROS level maintained longer time, and the number of bacteria number was declined in the shrimp intestinal lumen than those in the control group, but the survival rate of the MjCAT-RNAi shrimp was declined. Further study demonstrated that the intestinal villi protruded from epithelial lining of the intestinal wall were damaged by the high ROS level in MjCAT-knockdown shrimp. These results suggested that MjCAT participated in the intestinal host-microbe homeostasis by regulating ROS level. PMID:26314524

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

    SciTech Connect

    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.

  11. Structural analysis of catalase from two Musa accessions, FHIA18 and Williams, and from Ravenala madagascariensis.

    PubMed

    Khoyratty, Sher-ullah S S; Souza, Manoel T; Jaufeerally-Fakim, Yasmina

    2008-01-01

    Nucleotide sequences of catalase were obtained following amplification using specific primers and were blasted against Musa acuminata catalase 2 mRNA from NCBI (157418810). Clustering of the amino acid sequences from NCBI was done using Clustal X. The latter revealed that FHIA18 catalase is more related to Ravenala madagascariensis (Musa relative) catalase while the Williams catalase is more related to a clade containing a Musa acuminata (Musa ancestor) catalase from NCBI. The tertiary structures and the catalase consensus functional sites, based on the Pseudomonas syringae catalase structural template, were obtained for FHIA18, Williams, Ravenala madagascariensis and Musa acuminata catalases. They were found to differ slightly. Using known features of catalase active sites, four pre-requisite criteria were defined to find such sites: (1) Position of tyrosine axial to heme determined by X-ray diffraction, (2) 7 conserved amino acids in the active site found by sequence alignment, (3) favourable docking energy, and (4) presence of an unobstructed long tunnel that leads the ligand to the active site. Two differing potential docking sites were found for both FHIA18 and Williams that fit a maximum number of criteria. In terms of 1D sequence, the region of the docking site for Williams is within the catalase domains as seen upon NCBI blast. The counterpart of FHIA18 for the same region is not. This sequence difference between FHIA18 and Williams affects the best docking site in FHIA18 and Williams in silico. PMID:19374128

  12. Inhibition of host cell catalase by Mycoplasma pneumoniae: a possible mechanism for cell injury.

    PubMed Central

    Almagor, M; Yatziv, S; Kahane, I

    1983-01-01

    This study demonstrates that viable Mycoplasma pneumoniae cells inhibit catalase activity in several types of intact human cells as well as in solution. Human erythrocyte catalase was inhibited up to 72%, and the inhibition of catalase in human cultured skin fibroblasts, lung carcinoma epithelial cells, and ciliated epithelial cells from human nasal polyps ranged between 75 and 80%. UV light-killed mycoplasmas failed to inhibit catalase activity both in intact cells and in vitro. After M. pneumoniae infection of human cultured skin fibroblasts, the level of malonyldialdehyde, an indicator for membrane lipid peroxidation, was 3.5 times higher than in control fibroblasts. Virulent M. pneumoniae completely inhibited catalase activity in solution, whereas the nonvirulent strains had a lesser ability to inhibit catalase activity. These findings suggest that as a result of host cell catalase inhibition by M. pneumoniae, the toxicity of the hydrogen peroxide generated by the microorganism and the affected cell is enhanced, thereby inducing host cell damage. PMID:6407999

  13. Catalase degradation in sunflower cotyledons during peroxisome transition from glyoxysomal to leaf peroxisomal function. [Helianthus annuus

    SciTech Connect

    Eising, R.; Gerhardt, B.

    1987-06-01

    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 /sup 14/C-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/sup -1/ in contrast to the constants ranging from 0.304 day/sup -1/ to 0.515 day/sup -1/ during the other developmental stages. Density labeling experiments comprising labeling of catalase with /sup 2/H/sub 2/O and its isopycnic centrifugation on CsCl gradients demonstrated that the determinations of the degradation constants were not substantially affected by reutilization of /sup 14/C-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.

  14. Plating isolation of various catalase-negative microorganisms from soil

    NASA Technical Reports Server (NTRS)

    Labeda, D. P.; Hunt, C. M.; Casida, L. E., Jr.

    1974-01-01

    A unique plating procedure was developed that allows isolation, but not enumeration, of representatives of the catalase-negative soil microflora. The numbers recovered, however, are low as compared to the numbers recovered when the modified dilution-to-extinction isolation procedure is used. The latter procedure provides prolonged inoculation in sealed tubes containing a nutritionally rich broth medium over small submerged agar slants. In contrast, the plating procedure utilizes nutritionally minimal media and the shorter incubations mandated by the inherent problems associated with plating.

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

    PubMed Central

    Kawa?ek, 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 yeastHansenula 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, the CLS of cat cells was enhanced relative to the wild-type control, when cells were grown on methanol, which is oxidized by peroxisomal alcohol oxidase. At these conditions strongly enhanced ROS levels were observed during the exponential growth phase of cat cells. This was paralleled by activation of the transcription factor Yap1, as well as an increase in the levels of the antioxidant enzymes cytochrome c peroxidase and superoxide dismutase. Upon deletion of the genes encoding Yap1 or cytochrome c peroxidase, the CLS extension of cat cells on methanol was abolished. These findings reveal for the first time an important role of enhanced cytochrome c peroxidase levels in yeast CLS extension. PMID:23425686

  16. Fluorescence Spectrometry of the Interaction of Multi-Walled Carbon Nanotubes with Catalase

    NASA Astrophysics Data System (ADS)

    Fan, Y.; Li, Y.; Cai, H.; Li, J.; Miao, J.; Fu, D.; Yang, Q.

    2014-11-01

    The interaction of multi-walled carbon nanotubes (MWCNTs) with catalase is investigated using fluorescence and circular dichroism spectroscopic techniques. The results of the fluorescence experiments suggest that MWCNTs quench the intrinsic fluorescence of catalase via a static quenching mechanism. The circular dichroism spectral results reveal the unfolding of catalase with a significant decrease in the ?-helix content in the presence of MWCNTs, which indicates that the conformation of catalase is changed in the binding process, thereby remarkably decreasing its activity. The binding constants and the number of binding sites of the MWCNT to the catalase are calculated at different temperatures. The thermodynamic parameters, such as the changes in free energy (?G), enthalpy (?H), and entropy (?S), are calculated using thermodynamic equations. The fact that all negative values of ?G, ?H, and ?S are obtained suggests that the interaction of the MWCNTs with catalase is spontaneous, and that hydrogen bonding and van der Waals interactions play an important role in the binding process.

  17. Gut Catalase-Positive Bacteria Cross-Protect Adjacent Bifidobacteria from Oxidative Stress

    PubMed Central

    Rodríguez, Eva; Peirotén, Ángela; Landete, José María; Medina, Margarita; Arqués, Juan Luis

    2015-01-01

    Bifidobacteria isolated from infant gut and breast milk exhibited different abilities to grow under microaerobic conditions, alone or in the presence of added catalase. In the present study, we demonstrated that some Bifidobacterium strains unable to grow under microaerobic conditions were cross-protected on solid media from oxidative stress by adjacent colonies of gut catalase-positive Staphylococcus epidermidis or Escherichia coli, but not by a catalase-deficient E. coli. The results of this study support the possible contribution of catalase-positive bacteria to the establishment of certain bifidobacteria in non-anaerobic human niches of the infant gastrointestinal tract or mammary gland. PMID:26040451

  18. Extracellular localization of catalase is associated with the transformed state of malignant cells.

    PubMed

    Böhm, Britta; Heinzelmann, Sonja; Motz, Manfred; Bauer, Georg

    2015-12-01

    Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase. PMID:26140730

  19. Benfotiamine upregulates antioxidative system in activated BV-2 microglia cells

    PubMed Central

    Bozic, Iva; Savic, Danijela; Stevanovic, Ivana; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Chronic microglial activation and resulting sustained neuroinflammatory reaction are generally associated with neurodegeneration. Activated microglia acquires proinflammatory cellular profile that generates oxidative burst. Their persistent activation exacerbates inflammation, which damages healthy neurons via cytotoxic mediators, such as superoxide radical anion and nitric oxide. In our recent study, we have shown that benfotiamine (S-benzoylthiamine O-monophosphate) possesses anti-inflammatory effects. Here, the effects of benfotiamine on the pro-oxidative component of activity of LPS-stimulated BV-2 cells were investigated. The activation of microglia was accompanied by upregulation of intracellular antioxidative defense, which was further promoted in the presence of benfotiamine. Namely, activated microglia exposed to non-cytotoxic doses of benfotiamine showed increased levels and activities of hydrogen peroxide- and superoxide-removing enzymes—catalase and glutathione system, and superoxide dismutase. In addition, benfotiamine showed the capacity to directly scavenge superoxide radical anion. As a consequence, benfotiamine suppressed the activation of microglia and provoked a decrease in NO and ·O?2 production and lipid peroxidation. In conclusion, benfotiamine might silence pro-oxidative activity of microglia to alleviate/prevent oxidative damage of neighboring CNS cells. PMID:26388737

  20. Study of catalase adsorption on two mixed-mode ligands and the mechanism involved therein.

    PubMed

    Shiva Ranjini, S; Vijayalakshmi, M A

    2012-11-01

    Mixed-mode chromatography sorbents n-hexylamine HyperCel™ (HEA) and phenylpropylamine HyperCel™ (PPA) were evaluated for the study of adsorption of catalase from two different sources. Various parameters such as buffer composition, ionic strength and pH were investigated to study the mechanism of interaction of commercially available pre-purified catalase from Bovine liver, purified catalase from black gram (Vigna mungo) and crude extract of black gram containing catalase with these mixed-mode ligands. A simple and economical screening protocol for identifying optimal buffer conditions for adsorption and desorption of catalase was established with micro volumes of the sorbent in batch mode. With HEA HyperCel, it was observed that pre-purified catalase from both bovine liver and black gram was completely retained at pH 7.0, irrespective of the presence or absence of NaCl in the adsorption buffer, whereas the catalase from crude extract of black gram was completely retained only in the presence of 0.2 M salt in the adsorption buffer. The elution of catalase from both the sources was accomplished by lowering the pH to 4.5 in absence of salt. In case of PPA HyperCel, catalase from both the sources was very strongly adsorbed under different buffer conditions studied, and elution did not yield a significant catalase activity. From the screening experiments, it could be concluded that the interaction of catalase with HEA HyperCel could be dominated by hydrophobic forces with minor contributions from ionic interaction and with PPA HyperCel, it could be a combination of different non-covalent interactions acting on different loci on the surface of the protein. PMID:23108613

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  3. Forchlorfenuron detection based on its inhibitory effect towards catalase immobilized on boron nitride substrate.

    PubMed

    Xu, Qin; Cai, Lijuan; Zhao, Huijie; Tang, Jiaqian; Shen, Yuanyuan; Hu, Xiaoya; Zeng, Haibo

    2015-01-15

    An enzymatic procedure based on a catalase biosensor for the detection of forchlorfenuron (CPPU) has been reported in this work. Catalase was immobilized on boron nitride (BN) sheets dispersed in chitosan by adsorption. The immobilized catalase exhibited direct electron transfer character and excellent electrocatalytic activity towards H2O2 reduction. After introducing CPPU into the H2O2 containing phosphate buffer solution, the catalase-catalyzed H2O2 reduction current decreased. By measuring the current decrease, CPPU can be determined in the range of 0.5-10.0 µM with the detection limit of 0.07 ?M. The non-competitive inhibition behavior of CPPU towards catalase was verified by the Lineweaver-Burk plots. Long stability character has been ascribed to this biosensor. Possible use of this biosensor in flow systems is illustrated. The proposed biosensor has been successfully applied to CPPU determination in fruits samples with satisfactory results. PMID:25108110

  4. 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

    PubMed Central

    2012-01-01

    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?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 against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress. PMID:22551313

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

    PubMed Central

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

    1989-01-01

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

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

    PubMed

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

    2015-02-25

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

  7. Superoxide Dismutase and Catalase Genotypes in Pediatric Migraine Patients.

    PubMed

    Saygi, Semra; Erol, ?lknur; Alehan, Füsun; Yalç?n, Yaprak Y?lmaz; Kubat, Gözde; Ataç, Fatma Belgin

    2015-10-01

    This study compared superoxide dismutase (SOD) and catalase (CAT) alleles in 97 consecutive children and adolescents with migraine to 96 healthy children and adolescents. Isolated genomic DNA was used as a template for SOD1 (35 A/C), SOD2 16 C/T, and CAT2 [(-262 C/T) and (-21 A/T)] allele genotyping. The SOD2 16 C/T genotype and C allele frequency differed significantly between controls and migraine (P = .047; P = .038). CAT -21 AA genotype and A allele frequency were significantly higher in both migraine with aura patients (P = .013; P = .004) and migraine without aura patients (P = .003; P = .001) compared to controls. To our knowledge, this is the first demonstration of differences in SOD and CAT genotypes between pediatric migraine patients and age-matched controls. Further studies on the functional implications of these genetic variants on neural antioxidant capacity and the use of antioxidant modulators for migraine treatment are warranted. PMID:25818327

  8. Amelioration of hepatic reperfusion injury by superoxide dismutase and catalase

    SciTech Connect

    Clemens, M.G.; Burke, F.; Chaudry, I.H.

    1986-03-05

    Oxygen-derived free radicals have been implicated in reperfusion injury in various tissues. The present study determined if enzymatic scavenging of free radicals could improve recovery of hepatic function following ischemia. Livers from fasted rats were perfused with Krebs-HCO/sub 3/ buffer with substrates for gluconeogenesis for 30 min (control) followed by 60 min warm ischemia and 90 min reperfusion. At the beginning and end of ischemia the liver was flushed with buffered Ringer's with superoxide dismutase + catalase (150,000 U/L each)(SOD) or without additions (Untreated). Bile flow and glucose release were monitored during control and reperfusion periods and tissue sampled at the end of the experiment to determine tissue water and electrolytes. Bile flow and gluconeogenesis were markedly depressed after ischemia in both groups. At the end of 90 min reperfusion bile flow in Untreated and SOD were 23 +/- 6 and 46 +/- 8 ..mu..l/15 min (20% and 41% of control respectively, p < .01). Gluconeogenesis recovered to 83 +/- 4% of control in Untreated vs 103 +/- 6% with SOD (p < .05). Tissue water and electrolytes were not different. These results suggest that generation of oxygen-derived free radicals contributes to functional deficits in the liver following ischemia and that these defects can be attenuated by enzymatic scavenging.

  9. Differential expression of catalases in Vibrio parahaemolyticus under various stress conditions.

    PubMed

    Lin, Ling-Chun; Lin, Guang-Huey; Wang, Zi-Li; Tseng, Yi-Hsiung; Yu, Mei-Shiuan

    2015-10-01

    Among antioxidant enzymes, catalases protect microorganisms by degrading hydrogen peroxide under oxidative stress. In this study, the activities of at least four Vibrio parahaemolyticus catalases (Kat1 to Kat4) were differentially detected during different growth stages and under various stress conditions using zymographic analysis. Our results showed that only Kat2 is stable at 55 °C. Kat1 and Kat2 respond to hydrogen peroxide during the early stationary and exponential growth phases, respectively and the response decreases upon entering the stationary phase. Kat3 and Kat4 are bifunctional, exhibiting both catalase and peroxidase activities and are only expressed during the stationary phase, under starvation or under stress at pH 5.5. Our study also shows that expression of Kat3 and Kat4 depends on RpoS. We confirm that both monofunctional and bifunctional catalases are expressed and function differentially under various stresses to contribute total catalase activities for the survival of V. parahaemolyticus. A comparative genomic study among Vibrio species revealed that only V. parahaemolyticus contains two copies of genes that encode monofunctional and bifunctional catalases. We propose that both types of catalases, whether evolved or acquired horizontally through long-term evolution, may play crucial protective roles in V. parahaemolyticus in response to environmental fluctuations. PMID:26192211

  10. Catalase characterization and implication in bleaching of a symbiotic sea anemone.

    PubMed

    Merle, Pierre-Laurent; Sabourault, Cécile; Richier, Sophie; Allemand, Denis; Furla, Paola

    2007-01-15

    Symbiotic cnidarians are marine invertebrates harboring photosynthesizing microalgae (named zooxanthellae), which produce great amounts of oxygen and free radicals upon illumination. Studying antioxidative balance is then crucial to understanding how symbiotic cnidarians cope with ROS production. In particular, it is suspected that oxidative stress triggers cnidarian bleaching, i.e., the expulsion of zooxanthellae from the animal host, responsible for symbiotic cnidarian mass mortality worldwide. This study therefore investigates catalase antioxidant enzymes and their role in bleaching of the temperate symbiotic sea anemone Anemonia viridis. Using specific separation of animal tissues (ectoderm and endoderm) from the symbionts (zooxanthellae), spectrophotometric assays and native PAGE revealed both tissue-specific and activity pattern distribution of two catalase electrophoretypes, E1 and E2. E1, expressed in all three tissues, presents high sensitivity to the catalase inhibitor aminotriazole (ATZ) and elevated temperatures. The ectodermal E1 form is responsible for 67% of total catalase activity. The E2 form, expressed only within zooxanthellae and their host endodermal cells, displays low sensitivity to ATZ and relative thermostability. We further cloned an ectodermal catalase, which shares 68% identity with mammalian monofunctional catalases. Last, 6 days of exposure of whole sea anemones to ATZ (0.5 mM) led to effective catalase inhibition and initiated symbiont expulsion. This demonstrates the crucial role of this enzyme in cnidarian bleaching, a phenomenon responsible for worldwide climate-change-induced mass mortalities, with catastrophic consequences for marine biodiversity. PMID:17189829

  11. Over-Expression of Catalase in Myeloid Cells Confers Acute Protection Following Myocardial Infarction

    PubMed Central

    Cabigas, E. Bernadette; Somasuntharam, Inthirai; Brown, Milton E.; Che, Pao Lin; Pendergrass, Karl D.; Chiang, Bryce; Taylor, W. Robert; Davis, Michael E.

    2014-01-01

    Cardiovascular disease is the leading cause of death in the United States and new treatment options are greatly needed. Oxidative stress is increased following myocardial infarction and levels of antioxidants decrease, causing imbalance that leads to dysfunction. Therapy involving catalase, the endogenous scavenger of hydrogen peroxide (H2O2), has been met with mixed results. When over-expressed in cardiomyocytes from birth, catalase improves function following injury. When expressed in the same cells in an inducible manner, catalase showed a time-dependent response with no acute benefit, but a chronic benefit due to altered remodeling. In myeloid cells, catalase over-expression reduced angiogenesis during hindlimb ischemia and prevented monocyte migration. In the present study, due to the large inflammatory response following infarction, we examined myeloid-specific catalase over-expression on post-infarct healing. We found a significant increase in catalase levels following infarction that led to a decrease in H2O2 levels, leading to improved acute function. This increase in function could be attributed to reduced infarct size and improved angiogenesis. Despite these initial improvements, there was no improvement in chronic function, likely due to increased fibrosis. These data combined with what has been previously shown underscore the need for temporal, cell-specific catalase delivery as a potential therapeutic option. PMID:24853285

  12. Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification?

    PubMed

    Krych-Madej, Justyna; Gebicka, Lidia

    2015-09-01

    Hypochlorous acid (HOCl), highly reactive oxidizing and chlorinating species, is formed in the immune response to invading pathogens by the reaction of hydrogen peroxide with chloride catalyzed by the enzyme myeloperoxidase. Catalase, an important antioxidant enzyme, catalyzing decomposition of hydrogen peroxide to water and molecular oxygen, hampers in vitro HOCl formation, but is also one of the main targets for HOCl. In this work we have investigated HOCl-induced catalase inhibition at different pH, and the influence of flavonoids (catechin, epigallocatechin gallate and quercetin) on this process. It has been shown that HOCl-induced catalase inhibition is independent on pH in the range 6.0-7.4. Preincubation of catalase with epigallocatechin gallate and quercetin before HOCl treatment enhances the degree of catalase inhibition, whereas catechin does not affect this process. Our rapid kinetic measurements of absorption changes around the heme group have revealed that heme modification by HOCl is mainly due to secondary, intramolecular processes. The presence of flavonoids, which reduce active catalase intermediate, Compound I to inactive Compound II have not influenced the kinetics of HOCl-induced heme modification. Possible mechanisms of the reaction of hypochlorous acid with catalase are proposed and the biological consequences are discussed. PMID:26116387

  13. The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase.

    PubMed

    Campomanes, Pablo; Rothlisberger, Ursula; Alfonso-Prieto, Mercedes; Rovira, Carme

    2015-09-01

    Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H2O2). The origin of this disparity remains unknown due to the lack of atomistic information on the catalase-like reaction in HRP. Using QM(DFT)/MM metadynamics simulations, we uncover the mechanism for reduction of the HRP Compound I intermediate by H2O2 at atomic detail. The reaction begins with a hydrogen atom transfer, forming a peroxyl radical and a Compound II-like species. Reorientation of the peroxyl radical in the active site, concomitant with the transfer of the second hydrogen atom, is the rate-limiting step, with a computed free energy barrier (18.7 kcal/mol, ? 6 kcal/mol higher than the one obtained for catalase) in good agreement with experiments. Our simulations reveal the crucial role played by the distal pocket residues in accommodating H2O2, enabling formation of a Compound II-like intermediate, similar to catalases. However, out of the two pathways for Compound II reduction found in catalases, only one is operative in HRP. Moreover, the hydrogen bond network in the distal side of HRP compensates less efficiently than in catalases for the energetic cost required to reorient the peroxyl radical at the rate-determining step. The distal Arg and a water molecule in the "wet" active site of HRP have a substantial impact on the reaction barrier, compared to the "dry" active site in catalase. Therefore, the lower catalase-like efficiency of heme peroxidases compared to catalases can be directly attributed to the different distal pocket architecture, providing hints to engineer peroxidases with a higher rate of H2O2 disproportionation. PMID:26274391

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

    SciTech Connect

    Sohn, Eun Jeong; Kim, Dae Won; Kim, Young Nam; Kim, So Mi; Lim, Soon Sung; Kang, Tae-Cheon; Kwon, Hyeok Yil; Kim, Duk-Soo; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

    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.

  15. Physicochemical peculiarities of iron porphyrin-containing electrodes in catalase- and peroxidase-type biomimetic sensors

    NASA Astrophysics Data System (ADS)

    Sardarly, N. A.; Nagiev, T. M.

    2009-08-01

    New catalase- and peroxidase-type iron porphyrin biomimetic electrodes have been developed for determining ultralow concentrations of H2O2 and C2H5OH in aqueous solutions. Their physicochemical features have been studied. A mechanism of catalase and peroxidase reactions was suggested. Biomimetic electrodes did not lose their activity for a long time under the action of the oxidant, intermediates, and the final products of the decomposition of H2O2. Potentiometric biomimetic sensors of catalase and peroxidase types have been designed and studied.

  16. Deregulation of catalase, not MnSOD, is associated with necrotic death of p53-defective DF-1 cells under antimycin A-induced oxidative stress.

    PubMed

    You, Seungkwon; Kong, Byung-Whi; Jeon, Sun-Young; Foster, Douglas N; Kim, Hyunggee

    2004-10-31

    One of distinct genetic alterations in spontaneously immortalized DF-1 cells was found to be dysfunction of p53 and E2F-1 as well as altered antioxidant gene expression (upregulation of MnSOD and downregulation of catalase). We have characterized the cellular responses of primary and immortal DF-1 cells to oxidative stress and found that DF-1 cells were more sensitive to oxidative stress than their primary counterparts when treated with antimycin A. The increased DF-1 cell death by oxidative stress was accompanied by an increase in the levels of intracellular superoxide anions and hydrogen peroxide. The cell death in DF-1 cells by antimycin A showed none of the hallmarks of apoptosis, but displayed a significantly increased necrotic cell population. Anti-apoptotic Bcl-2 failed to inhibit oxidative-induced necrotic cell death in the DF-1 cells. However, this necrotic cell death was significantly decreased by treatment with hydrogen peroxide scavengers such as sodium pyruvate and N-acetyl-cysteine. Interestingly, overexpression of human catalase in DF-1 cells endowed cells resistant to the oxidative stress by antimycin A treatment, although the downregulation of MnSOD by an antisense strategy showed no evident change in the cytotoxic effect caused by antimycin A. Taken together, the present study might provide new therapeutic approach for tumor cells having the loss of p53 function and the altered antioxidant functions. PMID:15528999

  17. Endothelin-1 upregulates MCAM in melanocytes.

    PubMed

    Mangahas, Catherine R; dela Cruz, Gelo V; Schneider, Robert J; Jamal, Sumayah

    2004-12-01

    Melanoma cell adhesion molecule (MCAM) is a cell-surface adhesion molecule expressed on over 70% of metastatic melanoma cells but not expressed in normal melanocytes invivo. Protein levels of MCAM correlate with aggressive invasive behavior of melanoma cells in vitro and invivo. Here we demonstrate that endothelin-1 (ET-1) upregulates MCAM protein in primary human melanocytes. MCAM upregulation by ET-1 occurs irrespective of degree of melanocyte pigmentation and is dose-responsive. The drug BQ788 is an endothelin-B (ET(B)) receptor antagonist and inhibits upregulation of MCAM by ET-1. In addition, endothelin-3 (ET-3) and N-succinyl-[Glu9, Ala11, 15]-ET-1-1620, both selective ET(B) agonists, are potent upregulators of MCAM. These demonstrate a critical role for the ET(B) receptor in the upregulation of MCAM by ET-1 and related isoforms. MCAM mRNA abundance is also increased by ET-1 stimulation, thus the mechanism of MCAM protein upregulation may occur at the level of transcription. Our previous studies have demonstrated that ET-1 downregulates E-cadherin in melanocytes and melanoma cells. Since E-cadherin is a melanoma invasion suppressor, and MCAM is a melanoma invasion promoter, ET-1 may promote melanoma invasion and metastasis through the regulation of adhesion molecule expression. PMID:15610525

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

    NASA Astrophysics Data System (ADS)

    Johnson, Kristin A.

    2000-11-01

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

  19. Stability of catalase and its potential role in lipid oxidation in meat.

    PubMed

    Pradhan, A A; Rhee, K S; Hernández, P

    2000-04-01

    The activity of catalase in microbial growth-controlled and uncontrolled ground beef muscle (semimembranosus, SM) did not change (P>0.05) during 6-day storage at 4°C. Likewise, catalase activity in ground, beef SM and longissimus dorsi (LD), pork LD, and chicken breast (B) and thigh (T) muscles was not affected (P>0.05) by 2-month storage at -20°C, with or without mid-month thawing/refreezing. When sodium azide (a catalase inhibitor) was added to ground beef SM, lipid oxidation (as measured by peroxide values) during 4-day refrigeration was higher (P<0.05) in treated samples - 43 and 55% higher at day 2 and day 4, respectively - than in the controls. It was concluded that catalase would be stable during meat storage/distribution and contribute significantly to the antioxidative process in raw meat products. PMID:22060796

  20. research papers 1972 Murshudov et al. Catalase Acta Cryst. (2002). D58, 19721982

    E-print Network

    2002-01-01

    research papers 1972 Murshudov et al. Catalase Acta Cryst. (2002). D58, 1972±1982 Acta ) is associated with increased haem bending and is accompanied by a distal movement of the iron and the side chain

  1. Spectroscopic study on the interaction of catalase with bifendate and analogs

    NASA Astrophysics Data System (ADS)

    Wang, Ruiqiang; Zhang, Lu; Wang, Rui; Dou, Huanjing; Li, Hua; Wang, Yi; Pu, Juanjuan; Wang, Ruiyong

    2013-02-01

    The interactions of bifendate (DDB) or analogs (Bicyclol, I, II and III) with catalase are analyzed by spectrophotometric methods. The fluorescence spectra results show the intrinsic fluorescence of catalase is strongly quenched by DDB or analogs with a static quenching procedure. The binding constants are obtained at three temperatures. The thermodynamics parameters (?H, ?S, ?G) indicate the hydrophobic and electrostatic interactions play a major role in the interaction. The results of synchronous fluorescence, UV-vis absorption and three-dimensional fluorescence spectra demonstrate that the microenvironments of Trp residue of catalase are disturbed by the analogs. Thermodynamic results showed that DDB is the strongest quencher and bind to catalase with the highest affinity among five compounds.

  2. Human catalase is imported and assembled in peroxisomes of Saccharomyces cerevisiae.

    PubMed

    de Hoop, M J; Holtman, W L; Ab, G

    1993-01-01

    To study the conservation of peroxisomal targeting signals, we have determined the intracellular localization of human peroxisomal catalase when expressed in yeast. Using immunofluorescence, differential centrifugation and immunoelectron microscopy, we show that the protein is targeted to the peroxisomes of the heterologous cell and assembled in its active tetrameric form. These data show the conservation of the catalase targeting signal and import specificity between human and yeast peroxisomes. PMID:8442388

  3. Not so monofunctional--a case of thermostable Thermobifida fusca catalase with peroxidase activity.

    PubMed

    Lon?ar, Nikola; Fraaije, Marco W

    2015-03-01

    Thermobifida fusca is a mesothermophilic organism known for its ability to degrade plant biomass and other organics, and it was demonstrated that it represents a rich resource of genes encoding for potent enzymes for biocatalysis. The thermostable catalase from T. fusca has been cloned and overexpressed in Escherichia coli with a yield of 400 mg/L. Heat treatment of disrupted cells at 60 °C for 1 h resulted in enzyme preparation of high purity; hence, no chromatography steps are needed for large-scale production. Except for catalyzing the dismutation of hydrogen peroxide, TfuCat was also found to catalyze oxidations of phenolic compounds. The catalase activity was comparable to other described catalases while peroxidase activity was quite remarkable with a k obs of nearly 1000 s(-1) for catechol. Site directed mutagenesis was used to alter the ratio of peroxidase/catalase activity. Resistance to inhibition by classic catalase inhibitors and an apparent melting temperature of 74 °C classifies this enzyme as a robust biocatalyst. As such, it could compete with other commercially available catalases while the relatively high peroxidase activity also offers new biocatalytic possibilities. PMID:25227535

  4. Inhibitory effects of a novel Val to Thr mutation on the distal heme of human catalase

    PubMed Central

    Mashhadi, Zahra; Boeglin, William E.; Brash, Alan R.

    2014-01-01

    True catalases efficiently breakdown hydrogen peroxide, whereas the catalase-related enzyme allene oxide synthase (cAOS) is completely unreactive and instead metabolizes a fatty acid hydroperoxide. In cAOS a Thr residue adjacent to the distal His restrains reaction with H2O2 (Tosha et al (2006) J. Biol. Chem. 281:12610; De Luna et al (2013) J. Phys. Chem. B 117: 14635) and its mutation to the consensus Val of true catalases permits the interaction. Here we investigated the effects of the reciprocal experiment in which the Val74 of human catalase is mutated to Thr, Ser, Met, Pro, or Ala. The Val74Thr substitution decreased catalatic activity by 3.5-fold and peroxidatic activity by 3-fold. Substitution with Ser had similar negative effects (5- and 3-fold decreases). Met decreased catalatic activity 2-fold and eliminated peroxidatic activity altogether, whereas the Val74Ala substitution was well tolerated. (The Val74Pro protein lacked heme). We conclude that the conserved Val74 of true catalases helps optimize catalysis. There are rare substitutions of Val74 with Ala, Met, or Pro, but not with Ser of Thr, possibly due their hydrogen bonding affecting the conformation of His75, the essential distal heme residue for activity in catalases. PMID:25086217

  5. Mitochondrial catalase suppresses naturally occurring lung cancer in old mice

    PubMed Central

    Ge, Xuang; Pettan-Brewer, Christina; Morton, John; Carter, Katrina; Fatemi, Sy; Rabinovitch, Peter; Ladiges, Warren C.

    2015-01-01

    Lung cancer is generally difficult to detect until the late stages of disease, when it is much more difficult to treat because of the more aggressive and invasive behavior. Advanced lung cancer is much more common in older adults making it even more challenging to treat. Adenocarcinoma belongs to a category of non-small cell lung cancers, which comprise up to 40% of all lung cancers, and about half of these have an activating K-ras mutation. Because treatment relapses are common, more effective unconventional treatment and prevention methods are needed. In this regard, the antioxidant enzyme catalase targeted to mitochondria (mCAT) has been shown to delay aging and cancer in mice, and the progression of transgenic oncogene and syngeneic tumors was suppressed, helping support the notion that attenuation of mitochondria-generated hydrogen peroxide signaling is associated with an antitumor effect. In order to determine if mCAT has any effect on naturally occurring lung cancer of the adenocarcinoma type in old mice, the tumor incidence and progression were examined in the lungs of old mCAT transgenic and wild-type (WT) mice with a CB6F1 (Balb/c X C57BL/6) background. CB6F1 mice with a WT genotype were found to have a high incidence of adenomas at 24 months of age, which progressed to adenocarcinomas at 32 months of age. CB6F1 mice with the mCAT genotype had significantly reduced incidence and severity of lung tumors at both ages. Fibroblasts isolated from the lungs of old mCAT mice, but not WT mice, were shown to secrete soluble factors that inhibited lung tumor cell growth suggesting that stromal fibroblasts play a role in mediating the antitumor effects of mCAT. The aged CB6F1 mouse, with its high incidence of K-ras mutant lung cancer, is an excellent model to further study the anticancer potential of mitochondria-targeted therapy. PMID:26400209

  6. Purification and Characterization of a Novel Thermo-Alkali-Stable Catalase from Thermus brockianus

    SciTech Connect

    Thompson, Vicki Sue; Schaller, Kastli Dianne; Apel, William Arnold

    2003-10-01

    A novel thermo-alkali-stable catalase from Thermus brockianus was purified and characterized. The protein was purified from a T. brockianus cell extract in a three-step procedure that resulted in 65-fold purification to a specific activity of 5300 U/mg. The enzyme consisted of four identical subunits of 42.5 kDa as determined by SDS-PAGE and a total molecular mass measured by gel filtration of 178 kDa. The catalase was active over a temperature range from 30 to 94 C and a pH range from 6 to 10, with optimum activity occurring at 90 C and pH 8. At pH 8, the enzyme was extremely stable at elevated temperatures with half-lives of 330 h at 80 C and 3 h at 90 C. The enzyme also demonstrated excellent stability at 70 C and alkaline pH with measured half-lives of 510 h and 360 h at pHs of 9 and 10, respectively. The enzyme had an unusual pyridine hemochrome spectrum and appears to utilize eight molecules of heme c per tetramer rather than protoheme IX present in the majority of catalases studied to date. The absorption spectrum suggested that the heme iron of the catalase was in a 6-coordinate low spin state rather than the typical 5-coordinate high spin state. A Km of 35.5 mM and a Vmax of 20.3 mM/min·mg protein for hydrogen peroxide was measured, and the enzyme was not inhibited by hydrogen peroxide at concentrations up to 450 mM. The enzyme was strongly inhibited by cyanide and the traditional catalase inhibitor 3-amino-1,2,4-triazole. The enzyme also showed no peroxidase activity to peroxidase substrates o-dianisidine and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), a trait of typical monofunctional catalases. However, unlike traditional monofunctional catalases, the T. brockianus catalase was easily reduced by dithionite, a characteristic of catalase-peroxidases. The above properties indicate that this catalase has potential for applications in industrial bleaching processes to remove residual hydrogen peroxide from process streams.

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

    NASA Astrophysics Data System (ADS)

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

    1998-11-01

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

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

    PubMed Central

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

    2014-01-01

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

  9. Two Cytoplasmic Effectors of Phytophthora sojae Regulate Plant Cell Death via Interactions with Plant Catalases1

    PubMed Central

    Zhang, Meixiang; Li, Qi; Liu, Tingli; Liu, Li; Shen, Danyu; Zhu, Ye; Liu, Peihan; Zhou, Jian-Min; Dou, Daolong

    2015-01-01

    Plant pathogenic oomycetes, such as Phytophthora sojae, secrete an arsenal of host cytoplasmic effectors to promote infection. We have shown previously that P. sojae PsCRN63 (for crinkling- and necrosis-inducing proteins) induces programmed cell death (PCD) while PsCRN115 blocks PCD in planta; however, they are jointly required for full pathogenesis. Here, we find that PsCRN63 alone or PsCRN63 and PsCRN115 together might suppress the immune responses of Nicotiana benthamiana and demonstrate that these two cytoplasmic effectors interact with catalases from N. benthamiana and soybean (Glycine max). Transient expression of PsCRN63 increases hydrogen peroxide (H2O2) accumulation, whereas PsCRN115 suppresses this process. Transient overexpression of NbCAT1 (for N. benthamiana CATALASE1) or GmCAT1 specifically alleviates PsCRN63-induced PCD. Suppression of the PsCRN63-induced PCD by PsCRN115 is compromised when catalases are silenced in N. benthamiana. Interestingly, the NbCAT1 is recruited into the plant nucleus in the presence of PsCRN63 or PsCRN115; NbCAT1 and GmCAT1 are destabilized when PsCRN63 is coexpressed, and PsCRN115 inhibits the processes. Thus, PsCRN63/115 manipulates plant PCD through interfering with catalases and perturbing H2O2 homeostasis. Furthermore, silencing of catalase genes enhances susceptibility to Phytophthora capsici, indicating that catalases are essential for plant resistance. Taken together, we suggest that P. sojae secretes these two effectors to regulate plant PCD and H2O2 homeostasis through direct interaction with catalases and, therefore, overcome host immune responses. PMID:25424308

  10. The oxidation of chiral alcohols catalyzed by catalase in organic solvents

    SciTech Connect

    Magner, E.; Klibanov, A.M.

    1995-04-20

    The catalytic properties of bovine liver catalase have been investigated in organic solvents. In tetrahydrofuran, dioxane, and acetone (all containing 1% to 3% of water), the enzyme breaks down tert-butyl hydroperoxide several fold faster than in pure water. Furthermore, the rate of catalase-catalyzed production of tert-butanol from tert-butyl hydroperoxide increases more than 400-fold upon transition from aqueous buffer to ethanol as the reaction medium. The mechanistic rationale for this striking effect is that in aqueous buffer the rate-limiting step of the enzymatic process involves the reduction of catalase`s compound 1 by tert-butyl hydroperoxide. In ethanol, an additional step in the reaction scheme becomes available in which ethanol, greatly outcompeting the hydroperoxide, is oxidized by compound 1 regenerating the free enzyme. In solvents, such as acetonitrile or tetrahydrofuran, which themselves are not oxidizable by compound 1, catalase catalyzes the oxidation of numerous primary and secondary alcohols with tert-butyl hydroperoxide to the corresponding aldehydes or ketones. The enzymatic oxidation of some chiral alcohols (2,3-butanediol, citronellol, and menthol) under these conditions occurs enantioselectively. Examination of the enantioselectivity for the oxidation of 2,3-butanediol in a series of organic solvents reveals a considerable solvent dependence.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  12. A minor catalase/peroxidase from Burkholderia cenocepacia is required for normal aconitase activity.

    PubMed

    Lefebre, Mathew D; Flannagan, Ronald S; Valvano, Miguel A

    2005-06-01

    The opportunistic bacterium Burkholderia cenocepacia C5424 contains two catalase/peroxidase genes, katA and katB. To investigate the functions of these genes, katA and katB mutants were generated by targeted integration of suicide plasmids into the katA and katB genes. The catalase/peroxidase activity of the katA mutant was not affected as compared with that of the parental strain, while no catalase/peroxidase activity was detected in the katB mutant. However, the katA mutant displayed reduced resistance to hydrogen peroxide under iron limitation, while the katB mutant showed hypersensitivity to hydrogen peroxide, and reduced growth under all conditions tested. The katA mutant displayed reduced growth only in the presence of carbon sources that are metabolized through the tricarboxylic acid (TCA) cycle, as the growth defect was abrogated in cultures supplemented with glucose or glycerol. This phenotype was also correlated with a marked reduction in aconitase activity. In contrast, aconitase activity was not reduced in the katB mutant and parental strains. The authors conclude that the KatA protein is a specialized catalase/peroxidase that has a novel function by contributing to maintain the normal activity of the TCA cycle, while KatB is a classical catalase/peroxidase that plays a global role in cellular protection against oxidative stress. PMID:15942004

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

    PubMed Central

    Kirkman, H N; Gaetani, G F

    1984-01-01

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

  14. Relationship between uptake of mercury vapor by mushrooms and its catalase activity

    SciTech Connect

    Ogata, M.; Kenmotsu, K.; Hirota, N.; Naito, M.

    1981-12-01

    The uptake of mercury vapor by mushrooms (Shiitake) artifically grown on an oak tree and the uptake in vitro by catalase extracts prepared from mushroom Hay Bacillus and spinach are reported. Mushrooms were exposed to 1.4 mg/Hg/cu m for 11 days. Measurement of total mercury was as previously described (Ogata et al. 1978, 1979). Levels in mushrooms ranged from 0.4 +/- 0.1 ..mu..g/g at 0.5 days to 4.6 +/- 0.2 ..mu..g/g at 10.5 days and steady-state thereafter. In in vitro studies Hy uptake by mushroom catalase extract was estimated by the perborate method. Uptake was found to parallel catalase activity and was inhibited by potassium cyanide, sodium azide, and 3-amino-1,2,4-triazole. Similar results were obtained with Hay Bacillus and spinach catalase extracts. Results suggest that the level of mercury in the mushroom can be used as an indicator of mercury pollution in the environment. It is also suggested that catalase has an important role in uptake of mercury vapor in the plant. 2 tables (JMT)

  15. ICAM-1 targeted catalase encapsulated PLGA-b-PEG nanoparticles against vascular oxidative stress.

    PubMed

    Sari, Ece; Tunc-Sarisozen, Yeliz; Mutlu, Hulya; Shahbazi, Reza; Ucar, Gulberk; Ulubayram, Kezban

    2015-11-01

    Targeted delivery of therapeutics is the favourable idea, whereas it is possible to distribute the therapeutically active drug molecule only to the site of action. For this purpose, in this study, catalase encapsulated poly(d,l-lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles were developed and an endothelial target molecule (anti-ICAM-1) was conjugated to this carrier system in order to decrease the oxidative stress level in the target site. According to the enzymatic activity results, initial catalase activity of nanoparticles was increased from 27.39 U/mg to up to 45.66 U/mg by adding 5?mg/mL bovine serum albumin (BSA). After 4?h, initial catalase activity was preserved up to 46.98% while free catalase retained less than 4% of its activity in proteolytic environment. Furthermore, FITC labelled anti-ICAM-1 targeted catalase encapsulated nanoparticles (anti-ICAM-1/CatNPs) were rapidly taken up by cultured endothelial cells and concomitantly endothelial cells were resistant to H2O2 induced oxidative impairment. PMID:26471402

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

    PubMed

    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

  17. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide

    PubMed Central

    Shigli, Anand L; Sharma, Divya S; Thakur, Gagan

    2015-01-01

    ABSTRACT Aim: To evaluate the effects of postbleaching antioxidant application fluoridation treatment on the surface morphology and microhardness of human enamel. Materials and methods: Ten freshly extracted human maxillary central incisors were cut at cementoenamel junction. Crown portion was sectioned into six slabs which were divided into five groups: group A – untreated controls; group B – 35% carbamide peroxide (CP); group C – 35% CP and catalase; group D – treatment with 35% CP and 5% sodium fluoride; group E – 35% CP, catalase and 5% sodium fluoride. Thirty-five percent carbamide peroxide application included two applications of 30 minutes each at a 5-day interval. After treatment, the slabs were thoroughly washed with water for 10 seconds and stored in artificial saliva at 37°C until the next treatment. Two percent sodium fluoride included application for 5 minutes. Three catalase included application for 3 minutes. Results: After 5 days, groups B and C showed significantly decreased enamel microhardness compared to control. Group D specimens showed relatively less reduction in enamel micro-hardness than group C specimens. There is a marked increase in enamel microhardness in group E specimens. Conclusions: Fluoride take up was comparatively enhanced after catalase application resulting in less demineralization and increased microhardness. How to cite this article: Thakur R, Shigli AL, Sharma DS, Thakur G. Effect of Catalase and Sodium Fluoride on Human Enamel bleached with 35% Carbamide Peroxide. Int J Clin Pediatr Dent 2015;8(1):12-17. PMID:26124575

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

    PubMed Central

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

    2014-01-01

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

  19. Metabolic Damage and Premature Thymus Aging Caused by Stromal Catalase Deficiency.

    PubMed

    Griffith, Ann V; Venables, Thomas; Shi, Jianjun; Farr, Andrew; van Remmen, Holly; Szweda, Luke; Fallahi, Mohammad; Rabinovitch, Peter; Petrie, Howard T

    2015-08-18

    T lymphocytes are essential mediators of immunity that are produced by the thymus in proportion to its size. The thymus atrophies rapidly with age, resulting in progressive diminution of new T cell production. This decreased output is compensated by duplication of existing T cells, but it results in gradual dominance by memory T cells and decreased ability to respond to new pathogens or vaccines. Here, we show that accelerated and irreversible thymic atrophy results from stromal deficiency in the reducing enzyme catalase, leading to increased damage by hydrogen peroxide generated by aerobic metabolism. Genetic complementation of catalase in stromal cells diminished atrophy, as did chemical antioxidants, thus providing a mechanistic link between antioxidants, metabolism, and normal immune function. We propose that irreversible thymic atrophy represents a conventional aging process that is accelerated by stromal catalase deficiency in the context of an intensely anabolic (lymphoid) environment. PMID:26257169

  20. ENVIRONMENTAL EFFECTS ON SUPEROXIDE DISMUTASE AND CATALASE ACTIVITY AND EXPRESSION IN HONEY BEE.

    PubMed

    Nikoli?, Tatjana V; Pura?, Jelena; Or?i?, Snežana; Koji?, Danijela; Vujanovi?, Dragana; Stanimirovi?, Zoran; Gržeti?, Ivan; Ilijevi?, Konstantin; Šikoparija, Branko; Blagojevi?, Duško P

    2015-12-01

    Understanding the cellular stress response in honey bees will significantly contribute to their conservation. The aim of this study was to analyze the response of the antioxidative enzymes superoxide dismutase and catalase in honey bees related to the presence of toxic metals in different habitats. Three locations were selected: (i) Tunovo on the mountain Golija, as control area, without industry and large human impact, (ii) Belgrade as urban area, and (iii) Zaja?a, as mining and industrial zone. Our results showed that the concentrations of lead (Pb) in whole body of bees vary according to habitat, but there was very significant increase of Pb in bees from investigated industrial area. Bees from urban and industrial area had increased expression of both Sod1 and Cat genes, suggesting adaptation to increased oxidative stress. However, in spite increased gene expression, the enzyme activity of catalase was lower in bees from industrial area suggesting inhibitory effect of Pb on catalase. PMID:26314562

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

    PubMed

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

    2015-05-01

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

  2. Diminution of mouse epidermal superoxide dismutase and catalase activities by tumor promotors

    SciTech Connect

    Solanki, V.; Rana, R.S.; Slaga, T.J.

    1981-01-01

    The effects of phorbol ester tumor promoters and related compounds on superoxide dismutase (SOD) and catalase were examined. The treatment of adult mouse skin with 2 ..mu..g 12-0-tetradecanoylphorbol-13-acetate (TPA) resulted in a sustained decrease in the basal levels of both SOD and catalase activities in the epidermis. A decline in SOD activity occurred within 2 h after application and the maximum effect was seen at 16-17 h. The decrease in SOD activity was always accompanied by a similar decline in the epidermal catalase activity. The alterations in both enzymes occurred against a high background of enhanced protein synthesis which indicates that the effect of TPA is selective for SOD and catalase. Other tumor promoters such as phorbol 12,13-dibutyrate and the non-phorbol tumor promoter anthraline also lowered the activities of both the enzymes. Mezerein, a resiniferonol derivative with weak promoting activity but a potent stage-II promoter, appeared to be more potent than TPA in lowering the basal levels. These results indicate that damage which favors neoplastic progression would occur in TPA-treated mouse skin due to the accumulation of free radicals resulting from low levels of SOD and catalase activity. In addition, the TPA-caused decrease in the levels of SOD and catalase was not prevented by either retinoic acid, fluocinolone acetonide, tosyl amino-2-phenylethyl chloromethyl ketone, or butylated hydroxytoluene, suggesting that inhibition of tumor promotion by these agents is not mediated through alterations in the levels of enzymatic activities which decrease free radical concentrations.

  3. Catalase Therapy Corrects Oxidative Stress-Induced Pathophysiology in Incipient Diabetic Retinopathy

    PubMed Central

    Giordano, Courtney R.; Roberts, Robin; Krentz, Kendra A.; Bissig, David; Talreja, Deepa; Kumar, Ashok; Terlecky, Stanley R.; Berkowitz, Bruce A.

    2015-01-01

    Purpose. Preclinical studies have highlighted retinal oxidative stress in the pathogenesis of diabetic retinopathy. We evaluated whether a treatment designed to enhance cellular catalase reduces oxidative stress in retinal cells cultured in high glucose and in diabetic mice corrects an imaging biomarker responsive to antioxidant therapy (manganese-enhanced magnetic resonance imaging [MEMRI]). Methods. Human retinal Müller and pigment epithelial cells were chronically exposed to normal or high glucose levels and treated with a cell-penetrating derivative of the peroxisomal enzyme catalase (called CAT-SKL). Hydrogen peroxide (H2O2) levels were measured using a quantitative fluorescence-based assay. For in vivo studies, streptozotocin (STZ)-induced diabetic C57Bl/6 mice were treated subcutaneously once a week for 3 to 4 months with CAT-SKL; untreated age-matched nondiabetic controls and untreated diabetic mice also were studied. MEMRI was used to analytically assess the efficacy of CAT-SKL treatment on diabetes-evoked oxidative stress-related pathophysiology in vivo. Similar analyses were performed with difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. Results. After catalase transduction, high glucose-induced peroxide production was significantly lowered in both human retinal cell lines. In diabetic mice in vivo, subnormal intraretinal uptake of manganese was significantly improved by catalase supplementation. In addition, in the peroxisome-rich liver of treated mice catalase enzyme activity increased and oxidative damage (as measured by lipid peroxidation) declined. On the other hand, DFMO was largely without effect in these in vitro or in vivo assays. Conclusions. This proof-of-concept study raises the possibility that augmentation of catalase is a therapy for treating the retinal oxidative stress associated with diabetic retinopathy. PMID:25813998

  4. The euryhaline yeast Debaryomyces hansenii has two catalase genes encoding enzymes with differential activity profile.

    PubMed

    Segal-Kischinevzky, Claudia; Rodarte-Murguía, Beatriz; Valdés-López, Victor; Mendoza-Hernández, Guillermo; González, Alicia; Alba-Lois, Luisa

    2011-03-01

    Debaryomyces hansenii is a spoilage yeast able to grow in a variety of ecological niches, from seawater to dairy products. Results presented in this article show that (i) D. hansenii has an inherent resistance to H2O2 which could be attributed to the fact that this yeast has a basal catalase activity which is several-fold higher than that observed in Saccharomyces cerevisiae under the same culture conditions, (ii) D. hansenii has two genes (DhCTA1 and DhCTT1) encoding two catalase isozymes with a differential enzymatic activity profile which is not strictly correlated with a differential expression profile of the encoding genes. PMID:21061125

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

    PubMed

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

    1996-11-01

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

  6. Isolation and characterization of spinach photosystem II membrane-associated catalase and polyphenol oxidase.

    PubMed

    Sheptovitsky, Y G; Brudvig, G W

    1996-12-17

    Photosystem II (PSII) membranes exhibit catalase and polyphenol oxidase (PPO) activities. Mild heat treatment of PSII membranes for 90 min at 30 degrees C releases most of these enzyme activities into the supernatant, accompanied by a 7-fold activation of PPO. In contrast, mild heat treatment of thylakoid membranes does not release significant amounts of either activity, indicating that both enzymes are bound to the luminal surface of the thylakoid membrane. The heat-released PSII membrane-associated catalase and PPO have been purified and characterized. Catalase activity was correlated with a 63 kDa polypeptide which was purified by batch adsorption to anion-exchange beads followed by gel filtration. The PSII membrane-associated catalase is unstable in solution, probably due to irreversible aggregation. The enzyme was characterized in terms of molecular and subunit size, amino-acid composition, UV-visible absorption, heme content, pH optimum, inhibitor sensitivity, and K(m) value for H2O2. Its properties indicate that the PSII membrane-associated catalase is a luminal thylakoid membrane-bound heme enzyme that has not been identified previously. The residual catalase activity of PSII membranes after mild heat treatment is irreversibly inhibited with 3-amino-1,2,4-triazole, a specific inhibitor of heme catalases, without inhibition of O2-evolution activity. This result indicates that little, if any, of the catalase activity from PSII membranes in the dark is catalyzed by the O2-evolving center of PSII. PPO activity was correlated with a 48 kDa polypeptide. However, the 48 kDa polypeptide and another heat-released polypeptide of 72 kDa have the same N-terminal sequence, which is also identical to that of a known 64 kDa protein [Hind, G., Marshak, D. R., & Coughlan, S. J. (1995) Biochemistry 34, 8157-8164]. During heat treatment of PSII membranes and further manipulations it was found that the 72 kDa polypeptide was largely converted into the 48 kDa polypeptide. Thus, the 72 kDa polypeptide appears to be a latent precursor of the active 48 kDa PPO. The PSII membrane-associated PPO was purified by anion-exchange chromatography and was characterized in terms of substrate specificity, pH optimum, inhibitor sensitivity and native molecular weight. The heat-released PPO appears to be identical to the enzyme previously isolated from spinach thylakoid membranes [Golbeck, J. H., & Cammarata, K. V. (1981) Plant Physiol. 67, 977-984]. PMID:8973199

  7. The CYP2E1 inhibitor DDC up-regulates MMP-1 expression in hepatic stellate cells via an ERK1/2- and Akt-dependent mechanism

    PubMed Central

    Liu, Tianhui; Wang, Ping; Cong, Min; Xu, Youqing; Jia, Jidong; You, Hong

    2013-01-01

    DDC (diethyldithiocarbamate) could block collagen synthesis in HSC (hepatic stellate cells) through the inhibition of ROS (reactive oxygen species) derived from hepatocyte CYP2E1 (cytochrome P450 2E1). However, the effect of DDC on MMP-1 (matrix metalloproteinase-1), which is the main collagen degrading matrix metalloproteinase, has not been reported. In co-culture experiments, we found that DDC significantly enhanced MMP-1 expression in human HSC (LX-2) that were cultured with hepatocyte C3A cells either expressing or not expressing CYP2E1. The levels of both proenzyme and active MMP-1 enzyme were up-regulated in LX-2 cells, accompanied by elevated enzyme activity of MMP-1 and decreased collagen I, in both LX-2 cells and the culture medium. H2O2 treatment abrogated DDC-induced MMP-1 up-regulation and collagen I decrease, while catalase treatment slightly up-regulated MMP-1 expression. These data suggested that the decrease in ROS by DDC was partially responsible for the MMP-1 up-regulation. ERK1/2 (extracellular signal-regulated kinase 1/2), Akt (protein kinase B) and p38 were significantly activated by DDC. The ERK1/2 inhibitor (U0126) and Akt inhibitor (T3830) abrogated the DDC-induced MMP-1 up-regulation. In addition, a p38 inhibitor (SB203580) improved MMP-1 up-regulation through the stimulation of ERK1/2. Our data indicate that DDC significantly up-regulates the expression of MMP-1 in LX-2 cells which results in greater MMP-1 enzyme activity and decreased collagen I. The enhancement of MMP-1 expression by DDC was associated with H2O2 inhibition and coordinated regulation by the ERK1/2 and Akt pathways. These data provide some new insights into treatment strategies for hepatic fibrosis. PMID:23577625

  8. Iron deficiency upregulates Egr1 expression.

    PubMed

    Lee, Seung-Min; Lee, Sun Bok; Prywes, Ron; Vulpe, Christopher D

    2015-07-01

    Iron-deficient anemia is a prevalent disease among humans. We searched for genes regulated by iron deficiency and its regulated mechanism. cDNA microarrays were performed using Hepa1c1c7 cells treated with 100 ?M desferrioxamine (DFO), an iron chelator. Early growth response 1 (Egr1) was upregulated with at least 20-fold increase within 4 h and lasted for 24 h, which was confirmed by qRT-PCR. This activation was not seen by ferric ammonium citrate (FAC). DFO increased the transcriptional activity of Egr1-luc (-604 to +160) and serum response element (SRE)-luc reporters by 2.7-folds. In addition, cycloheximide lowered DFO-induced Egr1 mRNA levels. The upregulation of Egr1 by DFO was accompanied by sustained ERK signals along with phosphorylation of Elk-1. The ERK inhibitor (PD98059) prevented the DFO-induced Egr1 mRNAs. Overexpression of Elk-1 mutant (pElk-1S383A) decreased Egr1 reporter activity. DFO lowered reactive oxygen species (ROS) production and increased caspase 3/7 activity and cell death. DFO-induced iron deficiency upregulates Egr1 in part through transcriptional activation via ERK and Elk-1 signals, which may be important in the regulation of cell death in hepatoma cells. Our study demonstrated that iron depletion controlled the expression of Egr1, which might contribute to decisions about cellular fate in response to iron deficiency. PMID:25981695

  9. Cloning, characterization, and targeted disruption of cpcat1, coding for an in planta secreted catalase of Claviceps purpurea.

    PubMed

    Garre, V; Müller, U; Tudzynski, P

    1998-08-01

    Claviceps purpurea has been shown to secrete catalases in axenic and parasitic culture. In order to determine the importance of these enzymes in the host-parasite interaction, especially their role in overcoming oxidative stress imposed on the pathogen by the plant's defense system, the catR gene from A. niger was used to isolate a putative catalase gene from a genomic library of C. purpurea, cpcat1 consists of an open reading frame of 2,148 bp that is interrupted by five introns. Its derived gene product shows significant homology to fungal catalases and contains a putative signal peptide of 19 amino acids and three putative N-glycosylation sites, which indicates that CPCAT1 is a secreted catalase. Disruption of the gene by a gene replacement approach resulted in the loss of two catalase isoforms, CATC and CATD, strongly suggesting that they are both encoded by cpcat1. CATD is the major secreted catalase of C. purpurea and is furthermore the only catalase present in the honeydew of infected rye ears. Deletion mutants of cpcat1 were inoculated on rye plants and showed no significant reduction in virulence. Ovarian tissue and honeydew of plants inoculated with the mutants lacked CATD, confirming that this catalase is not essential for colonization of the host tissue by C. purpurea. PMID:9675893

  10. Induction and inactivation of catalase and superoxide dismutase of Escherichia coli by ozone

    SciTech Connect

    Whiteside, C.; Hassan, H.M.

    1987-09-01

    Oxyradicals have been implicated in ozone (O/sub 3/) toxicity and in other oxidant stress. In this study, we investigated the effects of O/sub 3/ on the biosynthesis of the antioxidant enzymes catalase and superoxide dismutase in Escherichia coli to determine their role in the defense against ozone toxicity. Inhibition of growth and loss of viability were observed in cultures exposed to ozone. Results also showed an increase in the activities of catalase and superoxide dismutase in cultures exposed to ozone, which was shown to be due to true induction rather than activation of preexisting apoproteins. Cessation of O/sub 3/ exposure resulted in 30 min of continual high rate of catalase biosynthesis followed by a gradual decrease in the level of the enzyme approaching that of control cultures. This decrease was attributed to a concomitant cessation of de novo enzyme synthesis and dilution of preexisting enzyme by cellular growth. Ozonation of cell-free extracts showed that superoxide dismutase and catalase are subject to oxidative inactivation by ozone. In vivo induction of these enzymes may represent an adaptive response evolved to protect cells against ozone toxicity.

  11. Low dose X -ray effects on catalase activity in animal tissue

    NASA Astrophysics Data System (ADS)

    Focea, R.; Nadejde, C.; Creanga, D.; Luchian, T.

    2012-12-01

    This study was intended to investigate the effect of low-dose X ray-irradiation upon the activity of catalase (CAT) in freshly excised chicken tissues (liver, kidney, brain, muscle). The tissue samples were irradiated with 0.5Gy and 2Gy respectively, in a 6 MV photon beam produced by a clinical linear accelerator (VARIAN CLINAC 2100SC). The dose rate was of 260.88cGy/min. at 100 cm source to sample distance. The catalase level was assayed spectrophotometrically, based on reaction kinetics, using a catalase UV assay kit (SIGMA). Catalase increased activity in various tissue samples exposed to the studied X ray doses (for example with 24 % in the liver cells, p<0.05) suggested the stimulation of the antioxidant enzyme biosynthesis within several hours after exposure at doses of 0.5 Gy and 2 Gy; the putative enzyme inactivation could also occur (due to the injuries on the hydrogen bonds that ensure the specificity of CAT active site) but the resulted balance of the two concurrent processes indicates the cell ability of decomposing the hydrogen peroxide-with benefits for the cell physiology restoration for the chosen low dose radiation.

  12. Catalase deciency drastically affects gene expression induced by high light in Arabidopsis thaliana

    E-print Network

    Gent, Universiteit

    in plants. Keywords: catalase de®ciency, Arabidopsis thaliana, microarray, hydrogen peroxide, high contributed equally to the paper. Summary In plants, hydrogen peroxide (H2O2) plays a major signaling role-light irradiation. Introduction A ®ne-tuned balance between hydrogen peroxide (H2O2) production and its removal

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

    EPA Science Inventory

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

  14. The Serum Levels of Malondialdehyde, Vitamin E and Erythrocyte Catalase Activity in Psoriasis Patients

    PubMed Central

    Ireddy, Shankargouda; Itagi, Inderraj; Kumar H., Siddesh

    2014-01-01

    Background: Psoriasis is a common skin disease which is characterized by increased epidermal proliferation and dermal inflammation affecting 0.1-3% of general population. Most of the psoriasis patients are young or middle aged adults, although no age exempted. The oxidative stress develops due to imbalance in oxidants and antioxidants, which was proposed to have role in psoriasis. Aims and Objectives: The presented research work was planned to evaluate oxidative stress by measuring serum malondialdehyde (MDA) as oxidant and serum vitamin E, erythrocyte catalase (CAT) activity as antioxidants in psoriasis patients. Materials and Methods: Total 90 clinically diagnosed psoriasis patients of age group of 20 to 60 years and without any drug therapy for preceding two months and 90 matched healthy controls were included in the presented study. The severity of psoriasis was determined by PASI score. The fasting blood sample collected and accessed for serum MDA, serum vitamin E and erythrocyte catalase activity. Results: The study results were compiled and statistical analysis was done using students t-test. Our results showed significantly increased levels of serum MDA (p<0.001) and significantly decreased serum vitamin E (p<0.001) as well as erythrocyte catalase activity (p<0.001) in psoriasis patients as compared to controls. Conclusion: The presented study concluded the oxidative stress in psoriasis, indicated by increased serum MDA and decreased Vitamin E, erythrocyte catalase activity. Our study also supports the possibility of involvement of oxidative stress in pathogenesis of psoriasis. PMID:25584212

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

    SciTech Connect

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

    1989-01-01

    Genetic deficiencies of glucose-6-phosphate dehydrogenase (G6PD) and NADPH predispose affected erythrocytes to destruction from peroxides. Conversely, genetic deficiencies of catalase do not predispose affected erythrocytes to peroxide-induced destruction. These observations have served to strengthen the assumption that the NADPH/glutathione/glutathione peroxidase pathway is the principal means for disposal of H/sub 2/O/sub 2/ in human erythrocytes. Recently, however, mammalian catalase was found to have tightly bound NADPH and to require NADPH for the prevention and reversal of inactivation by its toxic substrate (H/sub 2/O/sub 2/). Since both catalase and the glutathione pathway are dependent on NADPH for function, this finding raises the possibility that both mechanisms destroy H/sub 2/O/sub 2/ in human erythrocytes. A comparison of normal and acatalasemic erythrocytes in the present study indicated that catalase accounts for more than half of the destruction of H/sub 2/O/sub 2/ when H/sub 2/O/sub 2/ is generated at a rate comparable to that which leads to hemolysis in G6PD- deficient erythrocytes.

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

    E-print Network

    Pradhan, Abhijeet Amar

    1997-01-01

    water. Catalase activity in ground beef SM, beef longissimus dorsi (LD), chicken breast (B), chicken thigh (T), and pork LD muscle samples did not decline during 3 months of storage at-20'C, even when subjected to 3 freeze-thaw cycles. TBARS in all...

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

    NASA Technical Reports Server (NTRS)

    Yang, T.; Poovaiah, B. W.

    2002-01-01

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

  18. Catalase and superoxide dismutase in alfalfa root nodules. [Medicago sativa L

    SciTech Connect

    Becana, M.; Aparicio-Tejo, P.M.; Sanchez-Diaz, M.

    1986-04-01

    Catalase and superoxide dismutase (SOD), in scavenging H/sub 2/ O/sub 2/ and O/sub 2/, respectively, have been recently proposed to play a role in leghemoglobin protection. The occurrence of catalase and SOD activities in alfalfa (Medicago sativa L.) nodule cytosol is reported here. Enzymes were extracted at 0-4/sup 0/C from 0.5 g fresh nodules with 12 ml of a medium containing K-phosphate buffer 50 mM, pH 7.8 and Na/sub 2/EDTA 0.1 mM. The homogenate was filtered and centrifuged at 18,000 xg for 10 min, and the resulting supernatant was used for catalase assay. A further precipitation of leghemoglobin was required to avoid interferences with SOD determination. Catalase was determined by back-titration with KMnO/sub 4/. SOD was assayed by measuring the inhibition of nitro blue tetrazolium reduction. The sensitivity of SOD activity to CN/sup -/ was tested by including 1 mM KCN in the reaction mixture. Catalase activity of alfalfa nodule cytosol was 237 +/- 1 units/mg protein, decreasing very significantly (P < 0.01, Duncan's multiple range test) at 20 mM NO/sub 3//sup -/. Typical specific SOD activities were 94 +/- 5 and 65 +/- 4 units/mg protein, without CN/sup -/ and with CN/sup -/, respectively. Both activities increased very significantly at 20 mM NO/sub 3//sup -/. SOD activities with CN/sup -/ were 70-80% those without CN/sup -/ within the range of NO/sub 3//sup -/ investigated (0-20 mM).

  19. Catalase and superoxide dismutase activities as biomarkers of oxidative stress in workers exposed to mercury vapors

    SciTech Connect

    Perrin-Nadif, R.; Dusch, M.; Mur, J.M.; Koch, C.; Schmitt, P.

    1996-06-07

    We investigated the role of three blood antioxidant enzyme activities and total antioxidant status (TAS) as biological markers of oxidative stress in workers exposed to mercury (Hg{degrees}) vapors. Twenty-two female workers took part in the study. Blood and urine sampling for biological analyses was performed. The workers were classified into three subgroups according to their creatinine-corrected Hg concentration in urine. Blood antioxidant enzyme activities and TAS were compared between groups with nonparametric distribution-free methods. A significant difference existed in catalase activity and a slight, but not significant, difference existed in Cu{sup 2+}/Zn{sup 2+} superoxide dismutase (Cu{sup 2+}/Zn{sup 2+} SOD) activity between the three groups. No differences were observed in either the glutathione peroxidase activity or the TAS between these groups. Catalase and Cu{sup 2+}/Zn{sup 2+} SOD activities were increased in the groups of workers with higher creatinine-corrected urinary Hg concentrations when compared with the group of lower creatinine-corrected urinary Hg concentrations. Catalase activity was positively correlated with the creatinine-corrected concentration of Hg in urine, and Cu{sup 2+}/Zn{sup 2+} SOD activity was slightly correlated with the creatinine-corrected concentration of Hg in urine. The role of erythrocyte catalase and Cu{sup 2}/Zn{sup 2+} SOD activities we have measured is in agreement with the hypothesis of the involvement of reactive oxygen species production as an important event in chronic exposure to Hg{degrees} vapors in humans. In spite of the small sample size, results indicate that erythrocyte catalase and Cu{sup 2+}/Zn{sup 2+} SOD activities could be considered as markers of biological effect in workers exposed to Hg{degrees} vapors. 24 refs., 3 figs., 2 tabs.

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

    PubMed Central

    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 parameters a = b = 184.3 A and c = 305.5 A. An X-ray data set with 76% completeness at 3.2 A resolution was collected in a rotating anode generator using mirrors to improve the collimation of the beam. An initial solution was obtained by molecular replacement only when using a beef liver catalase tetramer model in which fragments with no sequence homology had been omitted, about 150 residues per subunit. In the structure found a single molecule of catalase A (a tetramer with accurate 222 molecular symmetry) is located in the asymmetric unit of the crystal with an estimated solvent content of about 61%. The preliminary analysis of the structure confirms the absence of a carboxy terminal domain as the one found in the catalase from Penicillium vitalae, the only other fungal catalase structure available. The NADPH binding site appears to be involved in crystal contacts, suggesting that heterogeneity in the occupancy of the nucleotide can be a major difficulty during crystallization. PMID:9041655

  1. A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes: DISCOVERY OF P450-TYPE HYDROPEROXIDE LYASE ACTIVITY IN A CATALASE.

    PubMed

    Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E; Calcutt, Wade M; Brash, Alan R; Samel, Nigulas

    2015-08-01

    In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using (18)O-labeled substrate and incubations in H2(18)O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom. PMID:26100625

  2. Understanding the role of the catalase/peroxide genes in H2O2 resistance of E. coli serotype O157:H7 biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Escherichia coli serotype O157:H7 defenses against H2O2 include the peroxiredoxin AhpC and three catalases: KatG (catalase-peroxidase), KatE (catalase), and the plasmid-encoded KatP (catalase/peroxidase). AhpC, KatG, and KatP are induced by OxyR in exponential phase, while KatE is indu...

  3. Fluid shear stress upregulates placental growth factor in the vessel wall via NADPH oxidase 4.

    PubMed

    Rashdan, Nabil A; Lloyd, Pamela G

    2015-11-15

    Placental growth factor (PLGF), a potent stimulator of arteriogenesis, is upregulated during outward arterial remodeling. Increased fluid shear stress (FSS) is a key physiological stimulus for arteriogenesis. However, the role of FSS in regulating PLGF expression is unknown. To test the hypothesis that FSS regulates PLGF expression in vascular cells and to identify the signaling pathways involved, human coronary artery endothelial cells (HCAEC) and human coronary artery smooth muscle cells were cultured on either side of porous Transwell inserts. HCAEC were then exposed to pulsatile FSS of 0.07 Pa ("normal," mimicking flow through quiescent collaterals), 1.24 Pa ("high," mimicking increased flow in remodeling collaterals), or 0.00 Pa ("static") for 2 h. High FSS increased secreted PLGF protein ?1.4-fold compared with static control (n = 5, P < 0.01), while normal FSS had no significant effect on PLGF. Similarly, high flow stimulated PLGF mRNA expression nearly twofold in isolated mouse mesenteric arterioles. PLGF knockdown using siRNA revealed that HCAEC were the primary source of PLGF in cocultures (n = 5, P < 0.01). Both H2O2 and nitric oxide production were increased by FSS compared with static control (n = 5, P < 0.05). N(G)-nitro-l-arginine methyl ester (100 ?M) had no significant effect on the FSS-induced increase in PLGF. In contrast, both catalase (500 U/ml) and diphenyleneiodonium (5 ?M) attenuated the effects of FSS on PLGF protein in cocultures. Diphenyleneiodonium also blocked the effect of high flow to upregulate PLGF mRNA in isolated arterioles. Further studies identified NADPH oxidase 4 as a source of reactive oxygen species for this pathway. We conclude that FSS regulates PLGF expression via NADPH oxidase 4 and reactive oxygen species signaling. PMID:26408539

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

    SciTech Connect

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

    1980-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  6. The roles of CATALASE2 in abscisic acid signaling in Arabidopsis guard cells.

    PubMed

    Jannat, Rayhanur; Uraji, Misugi; Morofuji, Miho; Hossain, Mohammad Anowar; Islam, Mohammad Muzahidul; Nakamura, Yoshimasa; Mori, Izumi C; Murata, Yoshiyuki

    2011-01-01

    We investigated the roles of catalase (CAT) in abscisic acid (ABA)-induced stomatal closure using a cat2 mutant and an inhibitor of CAT, 3-aminotriazole (AT). Constitutive reactive oxygen species (ROS) accumulation due to the CAT2 mutation and AT treatment did not affect stomatal aperture in the absence of ABA, whereas ABA-induced stomatal closure, ROS production, and [Ca(2+)](cyt) oscillation were enhanced. PMID:21979081

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

    PubMed

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

    2014-01-01

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

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

    SciTech Connect

    Davy, C.A.; Tesfay, Z.; Jones, J.; Rosenberg, R.C.; McCarthy, C.; Rosenberg, S.O.

    1986-05-01

    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/sup -/) for murine Cu-Zn-SOD was determined to be 6.8 x 10/sup -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.

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

    SciTech Connect

    Halaban, R.; Moellmann, G. )

    1990-06-01

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

  10. Catalase model systems. Decomposition of hydrogen peroxide catalysed by mesoferrihaem, deuteroferrihaem, coproferrihaem and haematoferrihaem.

    PubMed Central

    Hatzikonstantinou, H; Brown, S B

    1978-01-01

    The catalytic decomposition of H2O2 by deuteroferrihaem, mesoferrihaem, coproferrihaem and haematoferrihaem was studied as a model for the mechanism of action of catalase. For haematoferrihaem, anomalous but reproducible results were obtained, which could not be adequately explained. For each of the other ferrihaems studied, both monomeric and dimeric species catalysed decomposition, although the activity of monomer (aM) was much greater than that of dimer (aD). The pH variation of aD in the range 6.5--11 was consistent with an inverse dependence on [H+]1/2. The molecular mechanism whereby such a dependence could be achieved is not apparent. A study of the pH-dependence of aM in the range 6.5--11 revealed a linear inverse relationship with [H+]. This is interpreted in terms of attack by HO2- on ferrihaem monomer. The specific pH-independent rate constants for this reaction were in the order coproferrihaem greater than protoferrihaem greater than or equal to mesoferrihaem congruent to deuteroferrihaem. The order of magnitude of these rate constants is the same as that for catalysis by Fe(H2O)63+ and the second-order rate constant for decomposition of H2O2 by catalase. The implications on the mechanism of action of catalase are discussed. PMID:31868

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

    PubMed Central

    Halaban, R; Moellmann, G

    1990-01-01

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

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

    PubMed

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

    2015-02-01

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

  13. Amperometric biosensor for the detection of hydrogen peroxide using catalase modified electrodes in polyacrylamide.

    PubMed

    Varma, Shailly; Mattiasson, Bo

    2005-09-23

    A simple biosensor for the detection of hydrogen peroxide in organic solvents has been developed and coupled to a flow injection analysis (FIA) system. Catalase was entrapped in polyacrylamide gel and placed on the surface of platinum (working electrode) fixed in a Teflon holder with Ag-wire (auxiliary electrode), followed by addition of filter paper soaked in KCl. The entrapped catalase gel was held on the electrode using membranes. The effects of cellulose and polytetrafluroethylene (PTFE) membranes on the electrode response towards hydrogen peroxide have been studied. The modified electrode has been used to study the detection of hydrogen peroxide in solvents like water, dimethyl sulfoxide (DMSO), and 1,4-dioxane using amperometric techniques like cyclic voltammetry (CV) and FIA. The CV of modified catalase electrode showed a broad oxidation peak at -150 mV and a clear reduction peak at -212 mV in the presence of hydrogen peroxide. Comparison of CV with hydrogen peroxide in various solvents has been carried out. The electrode showed an irreversible kinetics with DMSO as the solvent. A flow cell has been designed in order to carry on FIA studies to obtain calibration plots for hydrogen peroxide with the modified electrode. The calibration plots in several solvents such as water, dimethyl sulfoxide, 1,4-dioxane have been obtained. The throughput of the enzyme electrode was 10 injections per hour. Due to the presence of membrane the response time of the electrode is concentration dependent. PMID:16099064

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

    PubMed Central

    Trawczy?ska, 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 permeabilization factor. Response surface methodology (RSM) has been applied in determining the influence of different parameters on permeabilization process. The aim of the study was to find such values of the process parameters that would yield maximum activity of catalase during decomposition of hydrogen peroxide. The optimum operating conditions for permeabilization process obtained by RSM were as follows: 53% (v/v) of ethanol concentration, temperature of 14.8 °C and treatment time of 40 min. After permeabilization, the activity of catalase increased ca. 40 times and its maximum value equalled to 4711 U/g. PMID:26019618

  15. Nucleotide diversity and gene expression of Catalase and Glutathione peroxidase in irradiated Scots pine (Pinus sylvestris L.) from the Chernobyl exclusion zone.

    PubMed

    Vornam, Barbara; Arkhipov, Andrey; Finkeldey, Reiner

    2012-04-01

    In the Chernobyl exclusion zone forest trees have to tolerate and to adapt to ionizing radiation, therefore the molecular basis of their adaptive responses is of the utmost interest. Based on SNP analysis and real time PCR nucleotide diversity and expression profiles of gene fragments of catalase (Cat) and glutathione peroxidase (GPx), which are known as radical scavenging genes, were analysed in the needles of irradiated pine trees of the Chernobyl exclusion zone. In acutely and chronically irradiated trees (50 years old) planted before the accident a higher nucleotide diversity of Cat and more somatic mutations were found compared to their control. Chronically irradiated trees (20 years old) planted after the accident showed a similar nucleotide diversity of Cat compared to their control and in both collectives one somatic mutation was found. The nucleotide diversity of GPx was higher in all analysed trees compared to Cat. No somatic mutation events were found in GPx. For both gene fragments, no association between the received dose in a tree and the nucleotide diversity and mutation events was detected. The expression profiles of Cat and GPx in acutely and chronically and in chronically irradiated trees were similar. Compared to their corresponding control collectives, Cat was up-regulated and GPx slightly down-regulated. PMID:22304996

  16. Unprecedented access of phenolic substrates to the heme active site of a catalase: substrate binding and peroxidase-like reactivity of Bacillus pumilus catalase monitored by X-ray crystallography and EPR spectroscopy.

    PubMed

    Loewen, Peter C; Villanueva, Jacylyn; Switala, Jacek; Donald, Lynda J; Ivancich, Anabella

    2015-05-01

    Heme-containing catalases and catalase-peroxidases catalyze the dismutation of hydrogen peroxide as their predominant catalytic activity, but in addition, individual enzymes support low levels of peroxidase and oxidase activities, produce superoxide, and activate isoniazid as an antitubercular drug. The recent report of a heme enzyme with catalase, peroxidase and penicillin oxidase activities in Bacillus pumilus and its categorization as an unusual catalase-peroxidase led us to investigate the enzyme for comparison with other catalase-peroxidases, catalases, and peroxidases. Characterization revealed a typical homotetrameric catalase with one pentacoordinated heme b per subunit (Tyr340 being the axial ligand), albeit in two orientations, and a very fast catalatic turnover rate (kcat ?=?339,000 s(-1) ). In addition, the enzyme supported a much slower (kcat ?=?20 s(-1) ) peroxidatic activity utilizing substrates as diverse as ABTS and polyphenols, but no oxidase activity. Two binding sites, one in the main access channel and the other on the protein surface, accommodating pyrogallol, catechol, resorcinol, guaiacol, hydroquinone, and 2-chlorophenol were identified in crystal structures at 1.65-1.95 Å. A third site, in the heme distal side, accommodating only pyrogallol and catechol, interacting with the heme iron and the catalytic His and Arg residues, was also identified. This site was confirmed in solution by EPR spectroscopy characterization, which also showed that the phenolic oxygen was not directly coordinated to the heme iron (no low-spin conversion of the Fe(III) high-spin EPR signal upon substrate binding). This is the first demonstration of phenolic substrates directly accessing the heme distal side of a catalase. PMID:25663126

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

    PubMed Central

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

    2012-01-01

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

  18. AGEs-Induced IL-6 Synthesis Precedes RAGE Up-Regulation in HEK 293 Cells: An Alternative Inflammatory Mechanism?

    PubMed Central

    Serban, Andreea Iren; Stanca, Loredana; Geicu, Ovidiu Ionut; Dinischiotu, Anca

    2015-01-01

    Advanced glycation end products (AGEs) can activate the inflammatory pathways involved in diabetic nephropathy. Understanding these molecular pathways could contribute to therapeutic strategies for diabetes complications. We evaluated the modulation of inflammatory and oxidative markers, as well as the protective mechanisms employed by human embryonic kidney cells (HEK 293) upon exposure to 200 ?g/mL bovine serum albumine (BSA) or AGEs–BSA for 12, 24 and 48 h. The mRNA and protein expression levels of AGEs receptor (RAGE) and heat shock proteins (HSPs) 27, 60 and 70, the activity of antioxidant enzymes and the expression levels of eight cytokines were analysed. Cell damage via oxidative mechanisms was evaluated by glutathione and malondialdehyde levels. The data revealed two different time scale responses. First, the up-regulation of interleukin-6 (IL-6), HSP 27 and high catalase activity were detected as early as 12 h after exposure to AGEs–BSA, while the second response, after 24 h, consisted of NF-?B p65, RAGE, HSP 70 and inflammatory cytokine up-regulation, glutathione depletion, malondialdehyde increase and the activation of antioxidant enzymes. IL-6 might be important in the early ignition of inflammatory responses, while the cellular redox imbalance, RAGE activation and NF-?B p65 increased expression further enhance inflammatory signals in HEK 293 cells. PMID:26307981

  19. Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells

    PubMed Central

    Bauer, Georg

    2015-01-01

    Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. PMID:26342455

  20. Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells.

    PubMed

    Bauer, Georg

    2015-12-01

    Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. PMID:26342455

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

    NASA Astrophysics Data System (ADS)

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

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

  2. Susceptibility of Treponema pallidum to the toxic products of oxygen reduction and the non-treponemal nature of its catalase.

    PubMed Central

    Steiner, B; Wong, G H; Graves, S

    1984-01-01

    We examined the sensitivity of Treponema pallidum (Nichols strain) to toxic products of oxygen reduction. T pallidum was sensitive to hydrogen peroxide at concentrations similar to those to which obligate anaerobes are sensitive. Accelerated death of T pallidum occurred at hydrogen peroxide concentrations below 50 mumol/l. Agents protective against hydrogen peroxide and the hydroxyl free radical (catalase, peroxidase, and mannitol) significantly enhanced treponemal survival in vitro under all three conditions of aerobiosis tested--that is, air, 3% oxygen, and 3% oxygen in conjunction with a reduced medium. Superoxide dismutase (which provides protection against superoxide radicals) did not enhance treponemal survival in normal media. When superoxide radicals were generated in the medium by means of a xanthine and xanthine oxidase system, however, the enzyme did protect T pallidum. A possible toxic involvement of singlet oxygen was also indicated by enhanced treponemal survival in air in the presence of histidine. Extracts of T pallidum from infected rabbit testes showed catalase activity which, on polyacrylamide gel electrophoresis, had the same relative mobility as purified rabbit catalase. The treponemal catalase activity was neutralised by anti rabbit catalase antiserum (raised in guinea pigs). This confirmed that the catalase was of rabbit origin and not an endogenous enzyme of T pallidum. We discuss the relation of these results to the obligate parasitism of T pallidum. Images PMID:6421449

  3. A comprehensive evaluation of catalase-like activity of different classes of redox-active therapeutics.

    PubMed

    Tovmasyan, Artak; Maia, Clarissa G C; Weitner, Tin; Carballal, Sebastián; Sampaio, Romulo S; Lieb, Dominik; Ghazaryan, Robert; Ivanovic-Burmazovic, Ivana; Ferrer-Sueta, Gerardo; Radi, Rafael; Reboucas, Julio S; Spasojevic, Ivan; Benov, Ludmil; Batinic-Haberle, Ines

    2015-09-01

    Because of the increased insight into the biological role of hydrogen peroxide (H2O2) under physiological and pathological conditions and the role it presumably plays in the action of natural and synthetic redox-active drugs, there is a need to accurately define the type and magnitude of reactions that may occur with this intriguing and key species of redoxome. Historically, and frequently incorrectly, the impact of catalase-like activity has been assigned to play a major role in the action of many redox-active drugs, mostly SOD mimics and peroxynitrite scavengers, and in particular MnTBAP(3-) and Mn salen derivatives. The advantage of one redox-active compound over another has often been assigned to the differences in catalase-like activity. Our studies provide substantial evidence that Mn(III) N-alkylpyridylporphyrins couple with H2O2 in actions other than catalase-related. Herein we have assessed the catalase-like activities of different classes of compounds: Mn porphyrins (MnPs), Fe porphyrins (FePs), Mn(III) salen (EUK-8), and Mn(II) cyclic polyamines (SOD-active M40403 and SOD-inactive M40404). Nitroxide (tempol), nitrone (NXY-059), ebselen, and MnCl2, which have not been reported as catalase mimics, were used as negative controls, while catalase enzyme was a positive control. The dismutation of H2O2 to O2 and H2O was followed via measuring oxygen evolved with a Clark oxygen electrode at 25°C. The catalase enzyme was found to have kcat(H2O2)=1.5×10(6)M(-1) s(-1). The yield of dismutation, i.e., the maximal amount of O2 evolved, was assessed also. The magnitude of the yield reflects an interplay between the kcat(H2O2) and the stability of compounds toward H2O2-driven oxidative degradation, and is thus an accurate measure of the efficacy of a catalyst. The kcat(H2O2) values for 12 cationic Mn(III) N-substituted (alkyl and alkoxyalkyl) pyridylporphyrin-based SOD mimics and Mn(III) N,N'-dialkylimidazolium porphyrin, MnTDE-2-ImP(5+), ranged from 23 to 88M(-1) s(-1). The analogous Fe(III) N-alkylpyridylporphyrins showed ~10-fold higher activity than the corresponding MnPs, but the values of kcat(H2O2) are still ~4 orders of magnitude lower than that of the enzyme. While the kcat(H2O2) values for Fe ethyl and n-octyl analogs were 803.5 and 368.4M(-1) s(-1), respectively, the FePs are more prone to H2O2-driven oxidative degradation, therefore allowing for similar yields in H2O2 dismutation as analogous MnPs. The kcat(H2O2) values are dependent on the electron deficiency of the metal site as it controls the peroxide binding in the first step of the dismutation process. SOD-like activities depend on electron deficiency of the metal site also, as it controls the first step of O2(?-) dismutation. In turn, the kcat(O2(?-)) parallels the kcat(H2O2). Therefore, the electron-rich anionic non-SOD mimic MnTBAP(3-) has essentially very low catalase-like activity, kcat(H2O2)=5.8M(-1) s(-1). The catalase-like activities of Mn(III) and Fe(III) porphyrins are at most, 0.0004 and 0.05% of the enzyme activity, respectively. The kcat(H2O2) values of 8.2 and 6.5M(-1) s(-1) were determined for electron-rich Mn(II) cyclic polyamine-based compounds, M40403 and M40404, respectively. The EUK-8, with modest SOD-like activity, has only slightly higher kcat(H2O2)=13.5M(-1) s(-1). The biological relevance of kcat(H2O2) of MnTE-2-PyP(5+), MnTDE-2-ImP(5+), MnTBAP(3-), FeTE-2-PyP(5+), M40403, M40404, and Mn salen was evaluated in wild-type and peroxidase/catalase-deficient E. coli. PMID:26026699

  4. Genes Upregulated in Human Fetal by Infection or Labor

    E-print Network

    Bryant-Greenwood, Gillian D.

    hybridization method in a homogeneous cell line*' before using it on a complex tissue such as the fetalGenes Upregulated in Human Fetal by Infection or Labor Membranes LILY S. TASHIMA, PhD, LYNNAE K hybridization can detect genes in fetal membranes that are upregulated by infection, preterm premature rupture

  5. A Single Nucleotide Polymorphism in Catalase Is Strongly Associated with Ovarian Cancer Survival

    PubMed Central

    Saed, Mohammed G.; Abusamaan, Mohammed S.; Dyson, Gregory; Diamond, Michael P.; Saed, Ghassan M.

    2015-01-01

    Ovarian cancer is the deadliest of all gynecologic cancers. Recent evidence demonstrates an association between enzymatic activity altering single nucleotide polymorphisms (SNP) with human cancer susceptibility. We sought to evaluate the association of SNPs in key oxidant and antioxidant enzymes with increased risk and survival in epithelial ovarian cancer. Individuals (n = 143) recruited were divided into controls, (n = 94): healthy volunteers, (n = 18), high-risk BRCA1/2 negative (n = 53), high-risk BRCA1/2 positive (n = 23) and ovarian cancer cases (n = 49). DNA was subjected to TaqMan SNP genotype analysis for selected oxidant and antioxidant enzymes. Of the seven selected SNP studied, no association with ovarian cancer risk (Pearson Chi-square) was found. However, a catalase SNP was identified as a predictor of ovarian cancer survival by the Cox regression model. The presence of this SNP was associated with a higher likelihood of death (hazard ratio (HR) of 3.68 (95% confidence interval (CI): 1.149–11.836)) for ovarian cancer patients. Kaplan-Meier survival analysis demonstrated a significant median overall survival difference (108 versus 60 months, p<0.05) for those without the catalase SNP as compared to those with the SNP. Additionally, age at diagnosis greater than the median was found to be a significant predictor of death (HR of 2.78 (95% CI: 1.022–7.578)). This study indicates a strong association with the catalase SNP and survival of ovarian cancer patients, and thus may serve as a prognosticator. PMID:26301412

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

    PubMed Central

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

    2014-01-01

    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 ccp1? cells and the accumulation of holoCcp1 in cta1? 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

  7. Touch automatically upregulates motor readiness in humans.

    PubMed

    van Ede, Freek; Winner, Tobias; Maris, Eric

    2015-12-01

    Goal-directed movements require effective integration of tactile input with ongoing movement. Here we investigated the functional consequences of such integration in healthy humans by probing the influence of spatially congruent and incongruent tactile stimuli on performance in a speeded button-press task. In addition, using magnetoencephalography (MEG), we evaluated whether the modulation of somato-motor beta (13-30 Hz) oscillations following tactile input-which has been shown to propagate to motor areas-could underlie this influence. We demonstrate that congruent tactile stimuli, despite being irrelevant to the motor task, lead to both faster and more accurate responses. We further show that this automatic upregulation of lateralized motor readiness 1) is specific to tactile input, 2) is independent of the spatial separation of the hands in peripersonal space, and 3) lasts (and remains facilitatory) for up to a second after the tactile input. This pattern of behavioral results is in line with recent physiological investigations showing that somatosensory and motor areas directly influence each other's processing capacity through joint changes in brain state. At the same time, however, the tactile-induced modulation of beta oscillations (one particular index of such a somato-motor state change) could not account for the observed movement facilitation, because it had a different time course. PMID:26400256

  8. Erythropoietin upregulation in pulmonary arterial hypertension

    PubMed Central

    2014-01-01

    Abstract The pathophysiologic alterations of patients with pulmonary arterial hypertension (PAH) are diverse. We aimed to determine novel pathogenic pathways from circulating proteins in patients with PAH. Multianalyte profiling (MAP) was used to measure 90 specifically selected antigens in the plasma of 113 PAH patients and 51 control patients. Erythropoietin (EPO) functional activity was assessed via in vitro pulmonary artery endothelial cell networking and smooth muscle cell proliferation assays. Fifty-eight patients had idiopathic PAH, whereas 55 had other forms of PAH; 5 had heritable PAH, 18 had connective tissue disease (15 with scleroderma and 3 with lupus erythematosis), 13 had portopulmonary hypertension, 6 had PAH associated with drugs or toxins, and 5 had congenital heart disease. The plasma-antigen profile of PAH revealed increased levels of several novel biomarkers, including EPO. Immune quantitative and histochemical studies revealed that EPO not only was significantly elevated in the plasma of PAH patients but also promoted pulmonary artery endothelial cell network formation and smooth muscle cell proliferation. MAP is a hypothesis-generating approach to identifying novel pathophysiologic pathways in PAH. EPO is upregulated in the circulation and lungs of patients with PAH and may affect endothelial and smooth muscle cell proliferation. PMID:25006446

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

    NASA Astrophysics Data System (ADS)

    Borovik, A. A.; Grebenko, A. I.; Melik-Adamyan, V. R.

    2011-07-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    PubMed

    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)}(?-2-MeOC6H4CO2)2(?-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 ?MT 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

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

    SciTech Connect

    Borovik, A. A.; Grebenko, A. I.; Melik-Adamyan, V. R.

    2011-07-15

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

  13. A catalase from the freshwater mussel Cristaria plicata with cloning, identification and protein characterization.

    PubMed

    Yang, Xilan; Li, Gang; Wen, Chungen; Hu, Baoqing; Deng, Lirong; Pei, Pengzu; Xie, Yanhai

    2011-09-01

    Catalase is an important antioxidant protein which can protect organisms against various oxidative stresses by eliminating hydrogen peroxide. The catalase cDNA of Cristaria plicata (cpCAT) was cloned from the haemocytes using degenerate primers by the method of 3' and 5' rapid amplification of cDNA ends PCR. The gene is 4863 bp long and has a total of two introns and three exons. The precise size and location of the introns and exons have been determined. In addition the full-length cDNA of cpCAT contained 2618 bp, The cDNA contained a 5' untranslated region (UTR) of 136 nucleotides, the 3' UTR of 979 bp with a canonical polyadenylation signal sequence AATAAA and a polyA tail, and an open reading frame (ORF) of 1503 bp, encoding 501 amino acid residues with 56.86 kDa predicted molecular weight. The theoretical isoelectric point was 6.77. BLAST analysis showed that the deduced amino acid sequence of cpCAT had significant homology to catalases from animals, plants and bacteria. The deduced amino acid sequence of cpCAT had characteristic features of catalase family such as catalytic site motif (61FNRERIPERVVHAKGAG77), heme-ligand signature motif (351RLYSYSDTH359), two glycosylation sites (N145, N436), NADPH binding site and the three catalytic amino acid residues (His72, Asn145 and Tyr355). It had no signal peptide. The phylogenetic tree indicated that cpCAT gene was very close to the gene of scallops, Chlamys farreri. The enzymatic activity of purified recombinant cpCAT was 11194.4 ± 40.4 U/mg, it might resist against H(2)O(2). The recombinant enzyme held higher thermal stability, the optimum temperature was 25 °C, it retained more than 82% activity between 25 and 60 °C. The stability of the recombinant enzyme were higher between pH 5 and 10, and the optimal pH value was 7.0. When cpCAT was treated with 2-4 moL/L urea and 1%-3% SDS, the activity was also stable, it kept more than 80% activity. PMID:21689759

  14. Catalytic activity of catalase under strong magnetic fields of up to 8 T

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Iwasaka, M.

    1996-04-01

    The question of whether or not magnetic fields affect enzymatic activity is of considerable interest in biomagnetics and biochemistry. This study focuses on whether magnetically related enzymatic activities can be affected by magnetic fields. We examined the effect of magnetic fields of up to 8 T on catalytic decomposition of hydrogen peroxide (H2O2). We observed changes in absorbance of reaction mixture of hydrogen peroxide and catalase at 240 nm, during and after magnetic field exposures. When the reaction mixture was not treated with nitrogen-gas bubbling, it was observed that the initial reaction rate of the reaction which was exposed to magnetic fields of up to 8 T was 50%-85% lower than the control data. This magnetic field effect was not observed, however, when the reaction mixture was bubbled with nitrogen gas to remove the dissolved oxygen molecules which were produced in the solution. We also measured concentration of dissolved oxygen which was produced by the decomposition of hydrogen peroxide. Dissolved oxygen concentration in the reaction mixture which was exposed to magnetic fields increased 20%-25% compared to the control solution. The results of the present study indicate that magnetic fields affect dynamic movement of oxygen bubbles which are produced in the reaction mixture by the decomposition of hydrogen peroxide, but not the catalytic activity of catalase itself.

  15. Catalase-like activity studies of the manganese(II) adsorbed zeolites

    NASA Astrophysics Data System (ADS)

    ?içek, Ekrem; Dede, Bülent

    2013-12-01

    Preparation of manganese(II) adsorbed on zeolite 3A, 4A, 5A. AW-300, ammonium Y zeolite, organophilic, molecular sieve and catalase-like enzyme activity of manganese(II) adsorbed zeolites are reported herein. Firstly zeolites are activated at 873 K for two hours before contact manganese(II) ions. In order to observe amount of adsorption, filtration process applied for the solution. The pure zeolites and manganese(II) adsorbed zeolites were analysed by FT-IR. As a result according to the FT-IR spectra, the incorporation of manganese(II) cation into the zeolite structure causes changes in the spectra. These changes are expected particularly in the pseudolattice bands connected with the presence of alumino and silicooxygen tetrahedral rings in the zeolite structure. Furthermore, the catalytic activities of the Mn(II) adsorbed zeolites for the disproportionation of hydrogen peroxide were investigated in the presence of imidazole. The Mn(II) adsorbed zeolites display efficiency in the disproportion reactions of hydrogen peroxide, producing water and dioxygen in catalase-like activity.

  16. Isozymes of Ipomoea batatas catechol oxidase differ in catalase-like activity.

    PubMed

    Gerdemann, C; Eicken, C; Magrini, A; Meyer, H E; Rompel, A; Spener, F; Krebs, B

    2001-07-01

    The amino acid sequences of two isozymes of catechol oxidase from sweet potatoes (Ipomoea batatas) were determined by Edman degradation of BrCN cleavage fragments of the native protein and by sequencing of amplified cDNA fragments. Sequence alignment and phylogenetic analysis of plant catechol oxidases revealed about 80% equidistance between the two I. batatas catechol oxidases and approximately 40--60% to catechol oxidases of other plants. When H(2)O(2) was applied as substrate the 39 kDa isozyme, but not the 40 kDa isozyme, showed catalase-like activity. The structure of the 40 kDa isozyme was modeled on the basis of the published crystal structure of the 39 kDa isozyme [T. Klabunde et al., Nat. Struct. Biol. 5 (1998) 1084]. The active site model closely resembled that of the 39 kDa isozyme determined by crystallography, except for a mutation of Thr243 (40 kDa isozyme) to Ile241 (39 kDa isozyme) close to the dimetal center. This residue difference affects the orientation of the Glu238/236 residue, which is thought to be responsible for the catalase-like activity of the 39 kDa isozyme for which a catalytic mechanism is proposed. PMID:11451442

  17. Influence of added catalase on chromosome stability and neoplastic transformation of mouse cells in culture.

    PubMed Central

    Jones, G. M.; Sanford, K. K.; Parshad, R.; Gantt, R.; Price, F. M.; Tarone, R. E.

    1985-01-01

    The generation of hydrogen peroxide (H2O2) and the derivative free hydroxyl radical (. OH) in cultures of mouse cells grown in the presence of visible light and ambient oxygen was shown previously to be implicated in chromatid damage. Furthermore, chromosome alterations appear to be associated with the spontaneous neoplastic transformation of mouse cells in culture. An attempt was made in this study to reduce the incidence of chromosomal aberrations and delay or prevent the onset of spontaneous neoplastic transformation of freshly isolated mouse cells, both fibroblasts and epidermal keratinocytes, by adding catalase to the culture medium, shielding the cultures from wavelengths less than 500 nm and providing a gas phase of 0-1% O2. These conditions significantly decreased the incidence of chromosomal aberrations in both cell types, and in fibroblasts prevented tumourigenicity in non-irradiated syngeneic mice, and increased latent periods for tumour development in X-irradiated mice. The epidermal keratinocytes were particularly resistant to spontaneous neoplastic transformation under all conditions tested. These observations on the protective effect of extracellular catalase suggest that H2O2, a normal metabolite, and/or the derivative .OH can directly or indirectly produce genetic damage and neoplastic transformation in mouse fibroblasts. PMID:2415146

  18. One-step purification and properties of catalase from leaves of Zantedeschia aethiopica.

    PubMed

    Trindade, H; Karmali, A; Pais, M S

    1988-12-01

    Catalase (E.C 1.11.1.6) was purified from leaves of Zandedeschia aethiopica to apparent homogeneity by a one-step hydrophobic interaction chromatography on a phenyl Sepharose CL-4B column. The purified enzyme preparation was obtained with a final recovery of enzyme activity of about 61% and a specific activity of 146 U/mg protein. The purified enzyme ran as a single protein band when analyzed both by native PAGE and SDS-PAGE corresponding to an Mr of 220,000 Da, which consists of 4 subunits with identical Mr of 54,000 Da. The pI of purified enzyme was found to be 5.2 by isoelectric focusing on ultrathin polyacrylamide gels. The purified catalase has an optimum temperature of activity at 40 degrees C, whereas it is stable between 0 degrees and 50 degrees C. As regards pH, the enzyme has an optimum activity at pH 7.0 and it is stable in the range pH 6-8. The absorption spectrum of the purified enzyme exhibited 2 peaks at 280 nm and 405 nm. PMID:3150680

  19. Catalase Activity as a Biomarker for Mild-Stress-Induced Robustness in Bacillus weihenstephanensis

    PubMed Central

    Effraimidou, Styliani; Abee, Tjakko

    2013-01-01

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

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

    PubMed

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

    2014-11-01

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

  1. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae?

    PubMed Central

    Abbott, Derek A.; Suir, Erwin; Duong, Giang-Huong; de Hulster, Erik; Pronk, Jack T.; van Maris, Antonius J. A.

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2? reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h?1 in anaerobic batch cultures containing lactic acid but only 0.16 h?1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae. PMID:19251894

  2. Molecular Cloning and Expression Analysis of a Catalase Gene (NnCAT) from Nelumbo nucifera.

    PubMed

    Dong, Chen; Zheng, Xingfei; Diao, Ying; Wang, Youwei; Zhou, Mingquan; Hu, Zhongli

    2015-11-01

    Rapid amplification cDNA end (RACE) assay was established to achieve the complete cDNA sequence of a catalase gene (NnCAT) from Nelumbo nucifera. The obtained full-length cDNA was 1666 bp in size and contained a 1476-bp open reading frame. The 3D structural model of NnCAT was constructed by homology modeling. The putative NnCAT possessed all the main characteristic amino acid residues and motifs of catalase (CAT) protein family, and the phylogenetic analysis revealed that NnCAT grouped together with high plants. Moreover, recombinant NnCAT showed the CAT activity (758 U/mg) at room temperature, holding high activity during temperature range of 20-50 °C, then the optimal pH of recombinant protein was assessed from pH 4 to pH 11. Additionally, real-time PCR assay demonstrated that NnCAT mRNA was expressed in various tissues of N. nucifera, with the highest expression in young leaf and lowest level in the root, and mRNA level of NnCAT was significantly augmented in response to short-time mechanical wounding. Different expression pattern of NnCAT gene suggested that NnCAT probably played a defensive role in the initial stages of oxidative stress, regulating the level of reactive oxygen species (ROS) by extracellular stimuli such as short-time mechanical wounding. PMID:26299377

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

    SciTech Connect

    Spychalla, J.P.; Desborough, S.L. )

    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.

  4. Evidence for separate substrate binding sites for hydrogen peroxide and cumene hydroperoxide (CHP) in the oxidation of ethanol by catalase

    SciTech Connect

    DeMaster, E.G.; Nagasawa,ss H.T.

    1986-03-01

    The oxidation of ethanol by purified bovine liver catalase (Sigma, C-40) can be supported by H/sub 2/O/sub 2/ or by CHP. The time course of the H/sub 2/O/sub 2/ supported reaction (using glucose/glucose oxidase as the H/sub 2/O/sub 2/ source) was linear for at least one hr, whereas the rate of acetaldehyde formation in the CHP (4.2 mM) supported reaction decreased with time. When catalase was exposed o CHP for 5 min before the addition of ethanol, the rate of CHP supported ethanol oxidation was reduced by more than 90% compared to incubations where the addition of ethanol preceded that of CHP. In the CHP inhibited state, the peroxidative activity of catalase was not restored by further addition of CHP or ethanol; however, addition of fresh catalase yielded its expected activity. Significantly, the CHP inhibited enzyme was equally effective as the untreated enzyme in catalyzing (a) the oxidation of ethanol in the presence H/sub 2/O/sub 2/ supported peroxidative activity as well as catalytic activity by CHP inhibited catalase points to separate binding sites for H/sub 2/O/sub 2/ and CHP in this reaction. Alternatively, CHP may bind adjacent to a common peroxide active site, thereby sterically impeding the binding of CHP - but not of H/sub 2/O/sub 2/ - to this active site.

  5. A factor converting viable but nonculturable Vibrio cholerae to a culturable state in eukaryotic cells is a human catalase

    PubMed Central

    Senoh, Mitsutoshi; Hamabata, Takashi; Takeda, Yoshifumi

    2015-01-01

    In our previous work, we demonstrated that viable but nonculturable (VBNC) Vibrio cholerae O1 and O139 were converted to culturable by coculture with eukaryotic cells. Furthermore, we isolated a factor converting VBNC V. cholerae to culturable (FCVC) from a eukaryotic cell line, HT-29. In this study, we purified FCVC by successive column chromatographies comprising UNO Q-6 anion exchange, Bio-Scale CHT2-1 hydroxyapatite, and Superdex 200 10/300 GL. Homogeneity of the purified FCVC was demonstrated by SDS-PAGE. Nano-LC MS/MS analysis showed that the purified FCVC was a human catalase. An experiment of RNAi knockdown of catalase mRNA from HT-29 cells and treatment of the purified FCVC with a catalase inhibitor, 3-amino-1,2,4-triazole confirmed that the FCVC was a catalase. A possible role of the catalase in converting a VBNC V. cholerae to a culturable state in the human intestine is discussed. PMID:25974870

  6. Protective effects of PEP-1-Catalase on stress-induced cellular toxicity and MPTP-induced Parkinson’s disease

    PubMed Central

    Eom, Seon Ae; Kim, Dae Won; Shin, Min Jea; Ahn, Eun Hee; Chung, Seok Young; Sohn, Eun Jeong; Jo, Hyo Sang; Jeon, Su-Jeong; Kim, Duk-Soo; Kwon, Hyeok Yil; Cho, Sung-Woo; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    Parkinson’s disease (PD) is a neurodegenerative disability caused by a decrease of dopaminergic neurons in the substantia nigra (SN). Although the etiology of PD is not clear, oxidative stress is believed to lead to PD. Catalase is antioxidant enzyme which plays an active role in cells as a reactive oxygen species (ROS) scavenger. Thus, we investigated whether PEP-1-Catalase protects against 1-methyl-4-phenylpyridinium (MPP+) induced SH-SY5Y neuronal cell death and in a 1-methyl-4-phenyl-1,2,3,6-trtrahydropyridine (MPTP) induced PD animal model. PEP-1-Catalase transduced into SH-SY5Y cells significantly protecting them against MPP+-induced death by decreasing ROS and regulating cellular survival signals including Akt, Bax, Bcl-2, and p38. Immunohistochemical analysis showed that transduced PEP-1-Catalase markedly protected against neuronal cell death in the SN in the PD animal model. Our results indicate that PEP-1-Catalase may have potential as a therapeutic agent for PD and other oxidative stress related diseases. [BMB Reports 2015; 48(7): 395-400] PMID:25322954

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

    PubMed

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

    2015-04-01

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

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

    SciTech Connect

    Riise, Ellen Kristin; Lorentzen, Marit Sjo; Helland, Ronny; Willassen, Nils Peder

    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, ? = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit.

  9. Catalase and superoxide dismutase activities after heat injury of listeria monocytogenes

    SciTech Connect

    Dallmier, A.W.; Martin, S.E.

    1988-02-01

    Four strains of Listeria monocytogenes were examined for catalase (CA) and superoxide dismutase (SOD) activities. The two strains having the highest CA activities (LCDC and Scott A) also possessed the highest SOD activities. The CA activity of heated cell extracts of all four strains examined decreased sharply between 55 and 60/sup 0/C. SOD was more heat labile than CA. Two L. monocytogenes strains demonstrated a decline in SOD activity after heat treatment at 45/sup 0/C, whereas the other two strains demonstrated a decline at 50/sup 0/C. Sublethal heating of the cells at 55/sup 0/C resulted in increased sensitivity to 5.5% NaCl. Exogenous hydrogen peroxide was added to suspensions of L. monocytogenes; strains producing the highest CA levels showed the greatest H/sub 2/O/sub 2/ resistance.

  10. Catalase HPI influences membrane permeability in Escherichia coli following near-UV stress

    SciTech Connect

    Leven, S.; Heimberger, A.; Eisenstark, A. )

    1990-09-28

    The katG gene in Escherichia coli encodes catalase HPI, which is involved in membrane transport and protects the cell during oxidative stress. Hydrogen peroxide (H2O2) induces synthesis of HPI. We examined the role of HPI in membrane permeability (proline uptake) following exposure to near-ultraviolet radiation (NUV). We found that NUV resulted in the same type of induction as H2O2. KatG::Tn10 cells experienced a large drop in uptake after NUV exposure, and levels remained low following incubation. A strain carrying a katG+ plasmid, however, showed considerably less decrease in uptake after NUV, and uptake quickly resumed upon incubation. Further, in an srd mutant which lacks 4-thiouracil, NUV resulted in only a small drop in proline uptake, which was immediately resumed.

  11. Sixty years from discovery to solution: crystal structure of bovine liver catalase form III

    SciTech Connect

    Foroughi, Leila M.; Kang, You-Na; Matzger, Adam J.

    2012-03-27

    The crystallization and structural characterization of bovine liver catalase (BLC) has been intensively studied for decades. Forms I and II of BLC have previously been fully characterized using single-crystal X-ray diffraction. Form III has previously been analyzed by electron microscopy, but owing to the thinness of this crystal form an X-ray crystal structure had not been determined. Here, the crystal structure of form III of BLC is presented in space group P212121, with unit-cell parameters a = 68.7, b = 173.7, c = 186.3 {angstrom}. The asymmetric unit is composed of the biological tetramer, which is packed in a tetrahedron motif with three other BLC tetramers. This higher resolution structure has allowed an assessment of the previously published electron-microscopy studies.

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

    PubMed

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

    2014-12-01

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

  13. A gas-phase amplified quartz crystal microbalance immunosensor based on catalase modified immunoparticles.

    PubMed

    Liu, Wei; Huang, Renliang; Qi, Wei; Wang, Mengfan; Su, Rongxin; He, Zhimin

    2015-02-21

    A novel signal amplification strategy for quartz crystal microbalance (QCM) based on catalytic gas generation was developed to construct an ultrasensitive immunosensor for the detection of proteins (immunoglobulin G, IgG, used as a model). A catalase modified immunoparticle was prepared to form a sandwich-type immunocomplex with the IgG and anti-IgG antibodies that were immobilized on the QCM sensor. The amount of immunoparticles on the sensor surface was thus controlled by the IgG concentration. Then H2O2 was added and catalyzed by catalase for oxygen generation. The generated oxygen replaced some of the liquid on the sensor surface, leading to the change in the shear modulus of the immunocomplex layer and the apparent viscosity and density of the liquid layer. Due to the ultrasensitive response of QCM to these changes, a significant frequency shift related to the IgG concentration was achieved. Different parameters, including the flow cell structure, operation temperature, immunoparticle concentration, and H2O2 concentration were optimized to achieve steady and efficient frequency shifts. Under the optimal conditions, the proposed gas-phase amplified QCM sensor could achieve up to 72 times improvement of detection sensitivity compared to the label-free sensor as a control, in the concentration range of 0.1-3.0 ?g mL(-1). The detection limit was also reduced from 236 ng mL(-1) to 51.0 ng mL(-1) at the 3Sblank level. PMID:25519742

  14. Novel synthetic SOD/catalase mimetics can mitigate capillary endothelial cell apoptosis caused by ionizing radiation.

    PubMed

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

    2010-06-01

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

  15. Inhibition of peroxidase and catalase activities and modulation of hydrogen peroxide level by inositol phosphoglycan-like compounds.

    PubMed

    Thomasz, L; Aran, M; Pizarro, R A; Ibañez, J; Pisarev, M A; Converso, D; Juvenal, G J; Krawiec, L

    2007-01-01

    Inositol phosphoglycan-like compounds are produced by the hydrolysis of the membrane bound glycosyl phosphoinositides. Besides being short term mediators of insulin action, they inhibit peroxidases and catalase, increasing the concentration of cellular hydrogen peroxide. Although high concentrations of hydrogen peroxide are toxic, moderate increases of its basal level are signals for different metabolic pathways. The inhibitor, localized in the cytosol of the cell, acts on peroxidases and catalase of the same tissue (homologous action) and of other tissues or organisms (heterologous action). The inositol phosphoglycan-like compound inhibits peroxidases with different prosthetic groups, i.e. containing iron such as: thyroid peroxidase, lactoperoxidase, horseradish peroxidase, soy bean peroxidase; and containing selenium such as glutathione peroxidase and 2-cys peroxiredoxin with no prosthetic group. Besides peroxidases, the inositol phosphoglycan-like compound inhibits catalase, another heme enzyme. The inhibition kinetics demonstrates a noncompetitive effect. The site of action is not the prosthetic group, given that the inhibitor does not produce any effect on the peak in the Soret region in the presence or absence of hydrogen peroxide. In conclusion, the inositol phosphoglycan-like compound is the general inhibitor of peroxidases and catalase involved in the modulation of hydrogen peroxide level that acts in different metabolic pathways as a signal transducer. PMID:17226108

  16. Novel immobilization process of a thermophilic catalase: efficient purification by heat treatment and subsequent immobilization at high temperature.

    PubMed

    Xu, Juan; Luo, Hui; López, Claudia; Xiao, Jing; Chang, Yanhong

    2015-10-01

    The main goal of the present work is to investigate a novel process of purification and immobilization of a thermophilic catalase at high temperatures. The catalase, originated from Bacillus sp., was overexpressed in a recombinant Escherichia coli BL21(DE3)/pET28-CATHis and efficiently purified by heat treatment, achieving a threefold purification. The purified catalase was then immobilized onto an epoxy support at different temperatures (25, 40, and 55 °C). The immobilizate obtained at higher temperatures reached its maximum activity in a shorter time than that obtained at lower temperatures. Furthermore, immobilization at higher temperatures required a lower ionic strength than immobilization at lower temperatures. The characteristics of immobilized enzymes prepared at different temperatures were investigated. The high-temperature immobilizate (55 °C) showed the highest thermal stability, followed by the 40 °C immobilizate. And the high-temperature immobilizate (55 °C) had slightly higher operational stability than the 25 °C immobilizate. All of the immobilized catalase preparations showed higher stability than the free enzyme at alkaline pH 10.0, while the alkali resistance of the 25 °C immobilizate was slightly better than that of the 40 and 55 °C immobilizates. PMID:26205324

  17. Erythrocyte Catalase Activity in More Frequent Microcytic Hypochromic Anemia: Beta-Thalassemia Trait and Iron Deficiency Anemia

    PubMed Central

    Lazarte, Sandra Stella; Mónaco, María Eugenia; Jimenez, Cecilia Laura; Ledesma Achem, Miryam Emilse; Terán, Magdalena María; Issé, Blanca Alicia

    2015-01-01

    Most common microcytic hypochromic anemias are iron deficiency anemia (IDA) and ?-thalassemia trait (BTT), in which oxidative stress (OxS) has an essential role. Catalase causes detoxification of H2O2 in cells, and it is an indispensable antioxidant enzyme. The study was designed to measure erythrocyte catalase activity (ECAT) in patients with IDA (10) or BTT (21), to relate it with thalassemia mutation type (?0 or ?+) and to compare it with normal subjects (67). Ninety-eight individuals were analyzed since September 2013 to June 2014 in Tucumán, Argentina. Total blood count, hemoglobin electrophoresis at alkaline pH, HbA2, catalase, and iron status were performed. ?-thalassemic mutations were determined by real-time PCR. Normal range for ECAT was 70,0–130,0?MU/L. ECAT was increased in 14% (3/21) of BTT subjects and decreased in 40% (4/10) of those with IDA. No significant difference (p = 0,245) was shown between normal and BTT groups, while between IDA and normal groups the difference was proved to be significant (p = 0,000). In ?0 and ?+ groups, no significant difference (p = 0,359) was observed. An altered ECAT was detected in IDA and BTT. These results will help to clarify how the catalase activity works in these anemia types. PMID:26527217

  18. Parthenolide-induced apoptosis in multiple myeloma cells involves reactive oxygen species generation and cell sensitivity depends on catalase activity.

    PubMed

    Wang, Wei; Adachi, Masaaki; Kawamura, Rina; Sakamoto, Hiroki; Hayashi, Toshiaki; Ishida, Tadao; Imai, Kohzoh; Shinomura, Yasuhisa

    2006-12-01

    The sesquiterpene lactone, parthenolide (PTL), possesses strong anticancer activity against various cancer cells. We report that PTL strongly induced apoptosis in 4 multiple myeloma (MM) cell lines and primary MM cells (CD38(+) high), but barely induced death in normal lymphocytes (CD38(-/+)low). PTL-mediated apoptosis correlated well with ROS generation and was almost completely inhibited by L-N-acetylcysteine (L-NAC), indicating the crucial role of oxidative stress in the mechanism. Among 4 MM cell lines, there is considerable difference in susceptibility to PTL. KMM-1 and MM1S cells sensitive to PTL possess less catalase activity than the less sensitive KMS-5 and NCI-H929 cells as well as normal lymphocytes. A catalase inhibitor 3-amino-1,2,4-triazole enhanced their PTL-mediated ROS generation and cell death. The siRNA-mediated knockdown of catalase in KMS-5 cells decreased its activity and sensitized them to PTL. Our findings indicate that PTL induced apoptosis in MM cells depends on increased ROS and intracellular catalase activity is a crucial determinant of their sensitivity to PTL. PMID:17051330

  19. Horizontal gene transfer confers adaptive advantages to phytopathogenic fungi: a case study of catalase-peroxidase in Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Horizontal gene transfer (HGT), the exchange and stable integration of genetic material between different evolutionary lineages, is widely observed in fungi. We hypothesize that successful stabilization of HGT elements provides adaptive advantages (e.g., virulence). Catalase/peroxidases (KatGs) are ...

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

    PubMed

    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 ?-barrel, the wrapping and the ?-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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  3. Further studies on O sub 2 -resistant photosynthesis and photorespiration in a tobacco mutant with enhanced catalase activity

    SciTech Connect

    Zelitch, I. )

    1990-02-01

    The increase in net photosynthesis in M{sub 4} progeny of an O{sub 2}-resistant tobacco (Nicotiana tabacum) mutant relative to wild-type plants at 21 and 42% O{sub 2} has been confirmed and further investigated. Self-pollination of an M{sub 3} mutant produced M{sub 4} progeny segregating high catalase phenotypes (average 40% greater than wild type) at a frequency of about 60%. The high catalase phenotype cosegregated precisely with O{sub 2}-resistant photosynthesis. About 25% of the F{sub 1} progeny of reciprocal crosses between the same M{sub 3} 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 CO{sub 2} as a percent of net photosynthesis in CO{sub 2}-free 21% O{sub 2} and 36% less in CO{sub 2}-free 42% O{sub 2} compared with wild type. The mutant leaf tissue also released less {sup 14}CO{sub 2} per (1-{sup 14}C)glycolate metabolized than wild type in normal air, consistent with less photorespiration in the mutant. The O{sub 2}-resistant photosynthesis appears to be caused by a decrease in photorespiration especially under conditions of high O{sub 2} where the stoichiometry of CO{sub 2} 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 H{sub 2}O{sub 2}.

  4. Secretion of a Fungal Extracellular Catalase by Claviceps purpurea During Infection of Rye: Putative Role in Pathogenicity and Suppression of Host Defense.

    PubMed

    Garre, V; Tenberge, K B; Eising, R

    1998-08-01

    ABSTRACT Hydrogen peroxide of the host origin accumulates in plant apoplasts in response to pathogen attack and probably functions directly in defense reactions or in signaling, according to a previous study. Since Claviceps purpurea produces compatible interactions with hundreds of host species, we hypothesized that the fungus might interfere with H(2)O(2)-mediated defense by means of secreted catalases. In axenic culture of C. purpurea, catalase activity accumulated in the medium and was inhibited by the catalase inhibitor aminotriazole. Polyacrylamide gel electrophoresis followed by diaminobenzidine (DAB)-mediated activity staining showed that one specific catalase found in culture filtrate was also present in rye ovaries infected with C. purpurea and in honeydew. This catalase form is probably induced during infection. In situ activity staining, using DAB-mediated enzyme-cytochemistry in electron microscopy, located catalase activity in hyphal walls during both axenic culture and infection of rye. Activity staining accumulated in periplasmic spaces and was especially strong at hyphal surfaces; control staining after aminotriazole inhibition was negative. Intracellular activity staining in organelles of the fungal secretory pathway substantiated that catalase was secreted by C. purpurea. With molecular cytology, anticatalase epitopes were localized with different heterologous catalase antibodies at sites corresponding to the activity staining pattern. In all infection phases, immunogold labeling indicated that the putative catalase was secreted via multivesicular bodies into the fungal wall and diffused into the host apoplast exclusively at the hostpathogen interface. The secretion of fungal catalase is a novel finding in phytopathology, and we discuss its role in the ubiquitous ergot disease. PMID:18944879

  5. Up-Regulated Expression of AOS-LOXa and Increased Eicosanoid Synthesis in Response to Coral Wounding

    PubMed Central

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

    2014-01-01

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

  6. Failure of catalase to protect against aflatoxin B{sub 1}-induced mouse lung tumorigenicity

    SciTech Connect

    Guindon, Katherine A.; Foley, Julie F.; Maronpot, Robert R.; Massey, Thomas E.

    2008-03-01

    The carcinogenic mycotoxin aflatoxin B{sub 1} (AFB{sub 1}) induces 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation in mouse lung, an effect that can be prevented by treatment with polyethylene glycol-conjugated catalase (PEG-CAT). G {yields} T transversion mutation in K-ras, an early event in AFB{sub 1}-induced mouse lung carcinogenesis, is thought to result from AFB{sub 1}-8,9-exo-epoxide binding to DNA to form AFB{sub 1}-N{sup 7}-guanine, but may also result from formation of 8-OHdG. Therefore, oxidative DNA damage may be important in AFB{sub 1} carcinogenicity. The objective of this study was to determine whether PEG-CAT would prevent AFB{sub 1} tumorigenicity. Mouse lung tumorigenesis was assessed following treatment of female A/J mice with 300 kU/kg PEG-CAT ip and/or 50 mg/kg AFB{sub 1}. Mice were killed 7 months post-treatment and tumors greater than 1 mm in diameter were excised. Unexpectedly, the mean number of tumors per mouse in the PEG-CAT + AFB{sub 1} group (8.81 {+-} 3.64, n = 47) was greater than that of the group treated with AFB{sub 1} alone (7.05 {+-} 3.45, n = 42) (P < 0.05). The tumors obtained from mice treated with PEG-CAT + AFB{sub 1} were larger than those from mice treated with AFB{sub 1} alone (P < 0.05). There was no difference in K-ras exon 1 mutation spectrum or in the histological diagnosis of tumors between AFB{sub 1} and PEG-CAT + AFB{sub 1} groups (P > 0.05). In vitro incubation with mouse liver catalase (CAT) resulted in conversion of [{sup 3}H]AFB{sub 1} into a DNA-binding species, a possible explanation for the results observed in vivo. These results demonstrate that PEG-CAT is not protective against AFB{sub 1} carcinogenicity in mouse lung despite preventing DNA oxidation.

  7. Upregulation of NAD(P)H oxidase 1 in hypoxia activates hypoxia-inducible factor 1 via increase in reactive oxygen species.

    PubMed

    Goyal, Parag; Weissmann, Norbert; Grimminger, Friedrich; Hegel, Cornelia; Bader, Lucius; Rose, Frank; Fink, Ludger; Ghofrani, Hossein A; Schermuly, Ralph T; Schmidt, Harald H H W; Seeger, Werner; Hänze, Jörg

    2004-05-15

    Hypoxia sensing and related signaling events, including activation of hypoxia-inducible factor 1 (HIF-1), represent key features in cell physiology and lung function. Using cultured A549 cells, we investigated the role of NAD(P)H oxidase 1 (Nox1), suggested to be a subunit of a low-output NAD(P)H oxidase complex, in hypoxia signaling. Nox1 expression was detected on both the mRNA and protein levels. Upregulation of Nox1 mRNA and protein occurred during hypoxia, accompanied by enhanced reactive oxygen species (ROS) generation. A549 cells, which were transfected with a Nox1 expression vector, revealed an increase in ROS generation accompanied by activation of HIF-1-dependent target gene expression (heme oxygenase 1 mRNA, hypoxia-responsive-element reporter gene activity). In A549 cells stably overexpressing Nox1, accumulation of HIF-1alpha in normoxia and an additional increase in hypoxia were noted. Interference with ROS metabolism by the flavoprotein inhibitor diphenylene iodonium (DPI) and catalase inhibited HIF-1 induction. This suggests that H2O2 links Nox1 and HIF-1 activation. We conclude that hypoxic upregulation of Nox1 and subsequently augmented ROS generation may activate HIF-1-dependent pathways. PMID:15110393

  8. Potential toxicity of sarafloxacin to catalase: Spectroscopic, ITC and molecular docking descriptions

    NASA Astrophysics Data System (ADS)

    Cao, Zhaozhen; Liu, Rutao; Yang, Bingjun

    2013-11-01

    The interaction between sarafloxacin and catalase (CAT) was studied by fluorescence spectroscopy, UV-visible absorption spectroscopy, circular dichroism (CD) spectroscopy, isothermal titration microcalorimetry (ITC) and molecular docking method. After deducting the inner filter effect, the fluorescence of CAT was quenched regularly by different concentrations of sarafloxacin. The quenching mechanism was studied by lifetime measurement, and it was proved to be mostly due to static quenching. The formation of sarafloxacin-CAT complex alters the micro-environment of amide moieties and tryptophan (Trp) residues, reduces the ?-helix content of the enzyme, changes the peripheral substituents on the porphyrin ring of heme and leads to the inhibition of the enzyme activity. Molecular docking study reveals that sarafloxacin is located between two ?-helix of CAT near to Trp 182 and Trp 185 residues, which supports the experimental results and helps to have a more clear understanding about the interaction mechanism. The change in the relative position of His 74 to heme induced by the variation of secondary structure is considered to be the major reason for the reduction of CAT activity. Moreover, sarafloxacin binds into a hydrophobic area of CAT mainly through hydrophobic interactions, which is consistent with the ITC analysis.

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

    SciTech Connect

    Fungjou Lu; Youngshin Chen . Dept. of Biochemistry); Tienshang Huang . 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.

  10. Endothelial targeting of liposomes encapsulating SOD/catalase mimetic EUK-134 alleviates acute pulmonary inflammation.

    PubMed

    Howard, Melissa D; Greineder, Colin F; Hood, Elizabeth D; Muzykantov, Vladimir R

    2014-03-10

    Production of excessive levels of reactive oxygen species (ROS) in the vascular endothelium is a common pathogenic pathway in many dangerous conditions, including acute lung injury, ischemia-reperfusion, and inflammation. Ineffective delivery of antioxidants to the endothelium limits their utility for management of these conditions. In this study, we devised a novel translational antioxidant intervention targeted to the vascular endothelium using PEG-liposomes loaded with EUK-134 (EUK), a potent superoxide dismutase/catalase mimetic. EUK loaded into antibody-coated liposomes (size 197.8±4.5 nm diameter, PDI 0.179±0.066) exerted partial activity in the intact carrier, while full activity was recovered upon liposome disruption. For targeting we used antibodies (Abs) to platelet-endothelial cell adhesion molecule (PECAM-1). Both streptavidin-biotin and SATA/SMCC conjugation chemistries provided binding of 125-150 Ab molecules per liposome. Ab/EUK/liposomes, but not IgG/EUK/liposomes: i) bound to endothelial cells and inhibited cytokine-induced inflammatory activation in vitro; and, ii) accumulated in lungs after intravascular injection, providing >60% protection against pulmonary edema in endotoxin-challenged mice (vs <6% protection afforded by IgG/liposome/EUK counterpart). Since the design elements of this drug delivery system are already in clinical use (PEG-liposomes, antibodies, SATA/SMCC conjugation), it is an attractive candidate for translational interventions using antioxidant molecules such as EUK and other clinically acceptable drugs. PMID:24412573

  11. Effect of salts and organic solvents on the activity of Halobacterium cutirubrum catalase.

    PubMed

    Lanyi, J K; Stevenson, J

    1969-05-01

    Catalase in extracts of the extreme halophile Halobacterium cutirubrum exhibits up to threefold stimulation by 0.5 to 1.5 m monovalent salts and by 0.1 m divalent salts. Above these concentrations, inhibition of enzyme activity is observed. The inhibitory effect, and to some extent the stimulation, is salt-specific; the effectiveness of a salt in inhibiting enzyme activity depends on both cation and anion. Thus, the order of effectiveness is MgCl(2) > LiCl > NaCl > KCl > NH(4)Cl, and LiCl > LiNO(3) > Li(2)SO(4). The magnitude of enzyme inhibition for the salts tested is positively correlated with their molar vapor pressure depression in aqueous solution. Stimulation of enzyme activity was observed when one salt was added at its optimal concentration in the presence of inhibiting concentrations of another salt, indicating that the effect on the enzyme is not due to changing water activity but probably to enzyme-salt interaction. Aqueous solutions of ethylene glycol, glycerol, and dimethyl sulfoxide containing no ions influence enzyme activity in the same manner as do salts. PMID:5784214

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

    PubMed

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

    2014-05-01

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

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

    PubMed

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

    2012-10-01

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

  14. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P<0.01), the quadratic effects of temperature were significant ( P<0.05), the linear effects of copper ion concentration were not significant ( P>0.05), and the quadratic effects of copper ion concentration were significant ( P<0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant ( P>0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  15. Effect of cyprodinil and fludioxonil pesticides on bovine liver catalase activity

    PubMed Central

    Karadag, Hasan; Ozhan, Fadil

    2015-01-01

    This study investigated if the use of the pesticides cyprodinil and fludioxonil produced an inhibitory effect on the bovine liver catalase (CAT) activity. It was documented that the activity of the enzyme decreased with increasing concentrations of cyprodinil and fludioxonil from 0 to 500 ppm. At pesticide concentrations of 250 and 500 ppm, the activity of CAT remained unchanged and passed to a steady state. The exposure to cyprodinil in concentrations of 10, 50, 100, 250 and 500 ppm, led to a decrease in the per cent of the CAT enzyme activity calculated as 45.4, 68.0, 73.0, 77.8 and 77.4, respectively. Similarly, the exposure to fludioxonil in concentrations of 10, 50, 100, 250 and 500 ppm, produced the following percentage decrease in the CAT enzyme activity: 20.0, 30.8, 42.8, 46.3 and 45.9, respectively. Cyprodinil inhibited CAT competitively, whereas the mechanism of fludioxonil inhibition over the enzyme was non-competitive.

  16. Catalase expression in MCF-7 breast cancer cells is mainly controlled by PI3K/Akt/mTor signaling pathway.

    PubMed

    Glorieux, Christophe; Auquier, Julien; Dejeans, Nicolas; Sid, Brice; Demoulin, Jean-Baptiste; Bertrand, Luc; Verrax, Julien; Calderon, Pedro Buc

    2014-05-15

    Catalase is an antioxidant enzyme that catalyzes mainly the transformation of hydrogen peroxide into water and oxygen. Although catalase is frequently down-regulated in tumors the underlying mechanism remains unclear. Few transcription factors have been reported to directly bind the human catalase promoter. Among them FoxO3a has been proposed as a positive regulator of catalase expression. Therefore, we decided to study the role of the transcription factor FoxO3a and the phosphatidylinositol-3 kinase (PI3K) signaling pathway, which regulates FoxO3a, in the expression of catalase. To this end, we developed an experimental model of mammary breast MCF-7 cancer cells that acquire resistance to oxidative stress, the so-called Resox cells, in which catalase is overexpressed as compared with MCF-7 parental cell line. In Resox cells, Akt expression is decreased but its phosphorylation is enhanced when compared with MCF-7 cells. A similar profile is observed for FoxO3a, with less total protein but more phosphorylated FoxO3a in Resox cells, correlating with its higher Akt activity. The modulation of FoxO3a expression by knockdown and overexpression strategies did not affect catalase expression, neither in MCF-7 nor in Resox cells. Inhibition of PI3K and mTOR by LY295002 and rapamycin, respectively, decreases the phosphorylation of downstream targets (i.e. GSK3? and p70S6K) and leads to an increase of catalase expression only in MCF-7 but not in Resox cells. In conclusion, FoxO3a does not appear to play a critical role in the regulation of catalase expression in both cancer cells. Only MCF-7 cells are sensitive and dependent on PI3K/Akt/mTOR signaling. PMID:24630930

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Up-Regulated Dicer Expression in Patients with Cutaneous Melanoma

    E-print Network

    Oliver, Douglas L.

    Up-Regulated Dicer Expression in Patients with Cutaneous Melanoma Zhihai Ma1 , Helen Swede2 , David Dicer in 81% of cutaneous, 80% of acrolentiginous and 96% of metastatic melanoma specimens compared compared to benign melanocytic nevi (P,0.0001). In patients with cutaneous melanomas, Dicer up

  20. Effect of catalase inactivation on levels of inorganic peroxides, superoxide dismutase, glutathione, oxygen consumption and life span in adult houseflies (Musca domestica).

    PubMed Central

    Allen, R G; Farmer, K J; Sohal, R S

    1983-01-01

    The effects of total inhibition of catalase, induced by 3-amino-1,2,4-triazole, on the adult housefly (Musca domestica) were examined. The lack of catalase activity had no effect on the longevity of the houseflies. Inorganic-peroxide concentration was elevated at younger ages, but declined in older flies. The rate of oxygen consumption by the flies was greatly decreased and the levels of oxidized as well as reduced glutathione were augmented. Superoxide dismutase activity showed a slight increase. This study suggests that loss of catalase activity does not affect survival of houseflies due to adaptive responses. PMID:6661212

  1. EUK-134, a synthetic superoxide dismutase and catalase mimetic, prevents oxidative stress and attenuates kainate-induced neuropathology

    PubMed Central

    Rong, Yongqi; Doctrow, Susan R.; Tocco, Georges; Baudry, Michel

    1999-01-01

    The present study tested the effects of EUK-134, a synthetic superoxide dismutase/catalase mimetic, on several indices of oxidative stress and neuropathology produced in the rat limbic system as a result of seizure activity elicited by systemic kainic acid (KA) administration. Pretreatment of rats with EUK-134 did not modify the latency for or duration of KA-induced seizure activity. It did produce a highly significant reduction in increased protein nitration, activator protein-1- and NF-?B-binding activity, and spectrin proteolysis as well as in neuronal damage resulting from seizure activity in limbic structures. These results support the hypothesis that kainate-induced excitotoxicity is caused, at least in part, by the action of reactive oxygen species. Furthermore, they suggest that synthetic superoxide dismutase/catalase mimetics such as EUK-134 might be used to prevent excitotoxic neuronal injury. PMID:10449791

  2. Dynamics of erythrocyte count, hemoglobin, and catalase activity in rat blood in hypokinesia, muscular activity and restoration

    NASA Technical Reports Server (NTRS)

    Taneyeva, G. V.; Potapovich, G. M.; Voloshko, N. A.; Uteshev, A. B.

    1980-01-01

    Tests were conducted to prove that muscular exertion (in this instance swimming) of different duration and intensity, as well as hypodynamia, result in an increase of hemoglobin and number of red blood cells in peripheral blood rats. Catalase activity increased with an increase in the duration of swimming, but only up to 6 hr; with 7-9 hr of swimming as well as in hypodynamia, catalase activity decreased. It was also observed that under hypodynamia as well as in 3, 5 and 6 hr exertion (swimming) the color index of blood decreased. Pressure chamber treatment (for 8 min each day for one week), alternating a 2 min negative pressure up to 35 mm Hg with 1 min positive pressure, increased the erythrocyte count and hemoglobin content.

  3. Catalase Expression Is Modulated by Vancomycin and Ciprofloxacin and Influences the Formation of Free Radicals in Staphylococcus aureus Cultures.

    PubMed

    Wang, Ying; Hougaard, Anni B; Paulander, Wilhelm; Skibsted, Leif H; Ingmer, Hanne; Andersen, Mogens L

    2015-09-01

    Detection of free radicals in biological systems is challenging due to their short half-lives. We have applied electron spin resonance (ESR) spectroscopy combined with spin traps using the probes PBN (N-tert-butyl-?-phenylnitrone) and DMPO (5,5-dimethyl-1-pyrroline N-oxide) to assess free radical formation in the human pathogen Staphylococcus aureus treated with a bactericidal antibiotic, vancomycin or ciprofloxacin. While we were unable to detect ESR signals in bacterial cells, hydroxyl radicals were observed in the supernatant of bacterial cell cultures. Surprisingly, the strongest signal was detected in broth medium without bacterial cells present and it was mitigated by iron chelation or by addition of catalase, which catalyzes the decomposition of hydrogen peroxide to water and oxygen. This suggests that the signal originates from hydroxyl radicals formed by the Fenton reaction, in which iron is oxidized by hydrogen peroxide. Previously, hydroxyl radicals have been proposed to be generated within bacterial cells in response to bactericidal antibiotics. We found that when S. aureus was exposed to vancomycin or ciprofloxacin, hydroxyl radical formation in the broth was indeed increased compared to the level seen with untreated bacterial cells. However, S. aureus cells express catalase, and the antibiotic-mediated increase in hydroxyl radical formation was correlated with reduced katA expression and catalase activity in the presence of either antibiotic. Therefore, our results show that in S. aureus, bactericidal antibiotics modulate catalase expression, which in turn influences the formation of free radicals in the surrounding broth medium. If similar regulation is found in other bacterial species, it might explain why bactericidal antibiotics are perceived as inducing formation of free radicals. PMID:26150471

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

    SciTech Connect

    Hassett, D.J.; Charniga, L.; Cohen, M.S. )

    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.

  5. The structure and peroxidase activity of a 33-kDa catalase-related protein from Mycobacterium avium ssp. paratuberculosis

    PubMed Central

    Pakhomova, Svetlana; Gao, Benlian; Boeglin, William E; Brash, Alan R; Newcomer, Marcia E

    2009-01-01

    True catalases are tyrosine-liganded, usually tetrameric, hemoproteins with subunit sizes of ?55–84 kDa. Recently characterized hemoproteins with a catalase-related structure, yet lacking in catalatic activity, include the 40–43 kDa allene oxide synthases of marine invertebrates and cyanobacteria. Herein, we describe the 1.8 Å X-ray crystal structure of a 33 kDa subunit hemoprotein from Mycobacterium avium ssp. paratuberculosis (annotated as MAP-2744c), that retains the core elements of the catalase fold and exhibits an organic peroxide-dependent peroxidase activity. MAP-2744c exhibits negligible catalatic activity, weak peroxidatic activity using hydrogen peroxide (20/s) and strong peroxidase activity (?300/s) using organic hydroperoxides as co-substrate. Key amino acid differences significantly impact prosthetic group conformation and placement and confer a distinct activity to this prototypical member of a group of conserved bacterial “minicatalases”. Its structural features and the result of the enzyme assays support a role for MAP-2744c and its close homologues in mitigating challenge by a variety of reactive oxygen species. PMID:19827095

  6. Impact of Microscale and Pilot-Scale Freeze-Drying on Protein Secondary Structures: Sucrose Formulations of Lysozyme and Catalase.

    PubMed

    Peters, Björn-Hendrik; Leskinen, Jari T T; Molnár, Ferdinand; Ketolainen, Jarkko

    2015-11-01

    Microscale (MS) freeze-drying offers rapid process cycles for early-stage formulation development. The effects of the MS approach on the secondary structures of two model proteins, lysozyme and catalase, were compared with pilot-scale (PS) vial freeze-drying. The secondary structures were assessed by attenuated total reflection Fourier transformed infrared spectroscopy. Formulations were made with increasing sucrose-protein ratios. Freeze-drying protocols involved regular cooling without thermal treatment and annealing with MS and PS equipment, and cooling rate variations with the MS. Principal component analysis of smoothed second-derivative amide I spectra revealed sucrose-protein ratio-dependent shifts toward ?-helical structures. Transferability of sucrose-protein formulations from MS to PS vial freeze-drying was evidenced at regular cooling rates. Local differences in protein secondary structures between the bottom and top of sucrose-catalase samples could be detected at the sucrose-catalase ratios of 1 and 2, this being related to the initial filling height and ice crystal morphology. Annealing revealed temperature, protein, formulation, and sample location-dependent effects influencing surface morphology at the top, or causing protein secondary structure perturbation at the bottom. With the MS approach, protein secondary structure differences at different cooling rates could be detected for sucrose-lysozyme samples at the sucrose-lysozyme ratio of 1. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3710-3721, 2015. PMID:26305147

  7. Transcriptional inhibition of the Catalase gene in phosphine-induced oxidative stress in Drosophila melanogaster.

    PubMed

    Liu, Tao; Li, Li; Zhang, Fanhua; Wang, Yuejin

    2015-10-01

    Phosphine (PH3) is a toxic substance to pest insects and is therefore commonly used in pest control. The oxidative damage induced by PH3 is considered to be one of the primary mechanisms of its toxicity in pest insects; however, the precise mode of PH3 action in this process is still unclear. In this study, we evaluated the responses of several oxidative biomarkers and two of the main antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD), after fumigation treatment with PH3 in Drosophila melanogaster as a model system. The results showed that larvae exposed to sub-lethal levels of PH3 (0.028?mg/L) exhibited lower aerobic respiration rates and higher levels of hydrogen peroxide (H2O2) and lipid peroxidation (LPO). Furthermore, unlike SOD, the activity and expression of CAT and its encoding gene were downregulated by PH3 in a time- and dose-dependent manner. Finally, the responses of six potential transcription factors of PH3 were determined by real-time polymerase chain reaction to explore the regulation mechanism of DmCAT by PH3. There were no significant effects of PH3 on three nuclear factor-kappa B homologs (DORSAL, DIF, and RELISH) or two activator protein-1 genes (JUN and FOS), while dramatic inhibition of DNA replication-related element factor (DREF) expression was observed after fumigation with PH3, suggesting that PH3 could inhibit the expression of DmCAT via the DRE/DREF system. These results confirmed that PH3 induces oxidative stress and targets CAT by downregulating its encoding gene in Drosophila. Our results provide new insight into the signal transduction mechanism between PH3 and its target genes. PMID:26453223

  8. Upregulating endogenous genes by an RNA-programmable artificial transactivator.

    PubMed

    Fimiani, Cristina; Goina, Elisa; Mallamaci, Antonello

    2015-09-18

    To promote expression of endogenous genes ad libitum, we developed a novel, programmable transcription factor prototype. Kept together via an MS2 coat protein/RNA interface, it includes a fixed, polypeptidic transactivating domain and a variable RNA domain that recognizes the desired gene. Thanks to this device, we specifically upregulated five genes, in cell lines and primary cultures of murine pallial precursors. Gene upregulation was small, however sufficient to robustly inhibit neuronal differentiation. The transactivator interacted with target gene chromatin via its RNA cofactor. Its activity was restricted to cells in which the target gene is normally transcribed. Our device might be useful for specific applications. However for this purpose, it will require an improvement of its transactivation power as well as a better characterization of its target specificity and mechanism of action. PMID:26152305

  9. Iron upregulates melanogenesis in cultured retinal pigment epithelial cells.

    PubMed

    Wolkow, Natalie; Li, Yafeng; Maminishkis, Arvydas; Song, Ying; Alekseev, Oleg; Iacovelli, Jared; Song, Delu; Lee, Jennifer C; Dunaief, Joshua L

    2014-11-01

    The purpose of our studies was to examine the relationship between iron and melanogenesis in retinal pigment epithelial cells, as prior observations had suggested that iron may promote melanogenesis. This relationship has potential clinical importance, as both iron overload and hyperpigmentation are associated with age-related macular degeneration (AMD). Human fetal retinal pigment epithelial cells and ARPE-19 cells were treated with iron in the form of ferric ammonium citrate, after which quantitative RT-PCR and electron microscopy were performed. Melanogenesis genes tyrosinase, tyrosinase-related protein 1, Hermansky-Pudlak Syndrome 3, premelanosome protein and dopachrome tautomerase were upregulated, as was the melanogenesis-controlling transcription factor, microphthalmia-associated transcription factor (MITF). Iron-treated cells had increased pigmentation and melanosome number. Multiple transcription factors upstream of MITF were upregulated by iron. PMID:25277027

  10. Upregulating endogenous genes by an RNA-programmable artificial transactivator

    PubMed Central

    Fimiani, Cristina; Goina, Elisa; Mallamaci, Antonello

    2015-01-01

    To promote expression of endogenous genes ad libitum, we developed a novel, programmable transcription factor prototype. Kept together via an MS2 coat protein/RNA interface, it includes a fixed, polypeptidic transactivating domain and a variable RNA domain that recognizes the desired gene. Thanks to this device, we specifically upregulated five genes, in cell lines and primary cultures of murine pallial precursors. Gene upregulation was small, however sufficient to robustly inhibit neuronal differentiation. The transactivator interacted with target gene chromatin via its RNA cofactor. Its activity was restricted to cells in which the target gene is normally transcribed. Our device might be useful for specific applications. However for this purpose, it will require an improvement of its transactivation power as well as a better characterization of its target specificity and mechanism of action. PMID:26152305

  11. Acoustic trauma triggers upregulation of serotonin receptor genes

    PubMed Central

    Smith, Adam R.; Kwon, Jae Hyun; Navarro, Marco; Hurley, Laura M.

    2014-01-01

    Hearing loss induces plasticity in excitatory and inhibitory neurotransmitter systems in auditory brain regions. Excitatory-inhibitory balance is also influenced by a range of neuromodulatory regulatory systems, but less is known about the effects of auditory damage on these networks. In this work, we studied the effects of acoustic trauma on neuromodulatory plasticity in the auditory midbrain of CBA/J mice. Quantitative PCR was used to measure the expression of serotonergic and GABAergic receptor genes in the inferior colliculus (IC) of mice that were unmanipulated, sham controls with no hearing loss, and experimental individuals with hearing loss induced by exposure to a 116 dB, 10 kHz pure tone for 3 hours. Acoustic trauma induced substantial hearing loss that was accompanied by selective upregulation of two serotonin receptor genes in the IC. The Htr1B receptor gene was upregulated tenfold following trauma relative to shams, while the Htr1A gene was upregulated threefold. In contrast, no plasticity in serotonin receptor gene expression was found in the hippocampus, a region also innervated by serotonergic projections. Analyses in the IC demonstrated that acoustic trauma also changed the coexpression of genes in relation to each other, leading to an overexpression of Htr1B compared to other genes.. These data suggest that acoustic trauma induces serotonergic plasticity in the auditory system, and that this plasticity may involve comodulation of functionally-linked receptor genes. PMID:24997228

  12. Catalase (KatA) Plays a Role in Protection against Anaerobic Nitric Oxide in Pseudomonas aeruginosa

    PubMed Central

    Su, Shengchang; Panmanee, Warunya; Wilson, Jeffrey J.; Mahtani, Harry K.; Li, Qian; VanderWielen, Bradley D.; Makris, Thomas M.; Rogers, Melanie; McDaniel, Cameron; Lipscomb, John D.; Irvin, Randall T.; Schurr, Michael J.; Lancaster, Jack R.; Kovall, Rhett A.; Hassett, Daniel J.

    2014-01-01

    Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ?nirS produced ?50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ?katA mutant and a mucoid mucA22 ?katA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ?katA mutant, and dramatically in a ?norCB mutant compared to basal levels of DNIC in PAO1 and ?nirS mutant. Expression of KatA dramatically reduced the DNIC levels in ?norCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ?6 ?M). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached. PMID:24663218

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

    PubMed

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

    2015-02-01

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

  14. Only one catalase, katG, is detectable in Rhizobium etli, and is encoded along with the regulator OxyR on a plasmid replicon.

    PubMed

    Vargas, María del Carmen; Encarnación, Sergio; Dávalos, Araceli; Reyes-Pérez, Agustín; Mora, Yolanda; García-de los Santos, Alejandro; Brom, Susana; Mora, Jaime

    2003-05-01

    The plasmid-borne Rhizobium etli katG gene encodes a dual-function catalase-peroxidase (KatG) (EC 1.11.1.7) that is inducible and heat-labile. In contrast to other rhizobia, katG was shown to be solely responsible for catalase and peroxidase activity in R. etli. An R. etli mutant that did not express catalase activity exhibited increased sensitivity to hydrogen peroxide (H(2)O(2)). Pre-exposure to a sublethal concentration of H(2)O(2) allowed R. etli to adapt and survive subsequent exposure to higher concentrations of H(2)O(2). Based on a multiple sequence alignment with other catalase-peroxidases, it was found that the catalytic domains of the R. etli KatG protein had three large insertions, two of which were typical of KatG proteins. Like the katG gene of Escherichia coli, the R. etli katG gene was induced by H(2)O(2) and was important in sustaining the exponential growth rate. In R. etli, KatG catalase-peroxidase activity is induced eightfold in minimal medium during stationary phase. It was shown that KatG catalase-peroxidase is not essential for nodulation and nitrogen fixation in symbiosis with Phaseolus vulgaris, although bacteroid proteome analysis indicated an alternative compensatory mechanism for the oxidative protection of R. etli in symbiosis. Next to, and divergently transcribed from the catalase promoter, an ORF encoding the regulator OxyR was found; this is the first plasmid-encoded oxyR gene described so far. Additionally, the katG promoter region contained sequence motifs characteristic of OxyR binding sites, suggesting a possible regulatory mechanism for katG expression. PMID:12724378

  15. Upregulated CDK16 Expression in Serous Epithelial Ovarian Cancer Cells

    PubMed Central

    Zhou, Qi; Yu, Yanni

    2015-01-01

    Background As CDK-16 has been shown to be upregulated in several transformed cancer lines, we hypothesized that the cyclin-dependent kinase 16 (CDK-16) may be upregulated in serous epithelial ovarian cancer (EOC) cells. Therefore, we comparatively examined the mRNA and protein expression of CDK-16 in samples resected from serous EOC patients and normal controls. Material/Methods Tissue samples were collected from 70 serous EOC patients and 40 normal controls. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was conducted to assess mRNA expression. CDK-16 protein expression was assessed by semi-quantitative immunohistochemical staining. Differences in mRNA and protein expression between serous EOC cells and normal tissue cells were tested with the Kruskal-Wallis test and analysis of variance (ANOVA). Results Both CDK-16 mRNA and protein expression were significantly higher in serous EOC tumor cells as compared to normal control ovarian cells (p<0.01). Although there was no significant correlation between CDK-16 mRNA expression and serous EOC stage (p=0.0794), there was a significant correlation between CDK-16 mRNA expression and serous EOC grade (p<0.0001). Moreover, there were significant correlations between CDK-16 protein expression and serous EOC stage (p<0.0001) and grade (p<0.0001). Conclusions CDK-16 upregulation in serous EOC cells may represent a negative feedback loop to promote ovarian cell differentiation in malignantly-transformed serous EOC cells. Further in-depth investigation on CDK-16’s role in serous EOC is needed. PMID:26546806

  16. Up-Regulated Dicer Expression in Patients with Cutaneous Melanoma

    PubMed Central

    Ma, Zhihai; Swede, Helen; Cassarino, David; Fleming, Elizabeth; Fire, Andrew; Dadras, Soheil S.

    2011-01-01

    Background MicroRNAs (miRNAs) are small non-coding RNAs (18–24 nucleotides) that have recently been shown to regulate gene expression during cancer progression. Dicer, a central enzyme in the multi-component miRNA biogenesis pathway, is involved in cutting precursor miRNAs to functionally mature forms. Emerging evidence shows that Dicer expression is deregulated in some human malignancies and it correlates with tumor progression, yet this role has not yet been investigated in skin cancers. Methods and Findings Using an anti-human monoclonal antibody against Dicer and immunohistochemistry, we compared the expression of Dicer protein among 404 clinically annotated controls and skin tumors consisting of melanocytic nevi (n?=?71), a variety of melanomas (n?=?223), carcinomas (n?=?73) and sarcomas (n?=?12). Results showed a cell-specific up-regulated Dicer in 81% of cutaneous, 80% of acrolentiginous and 96% of metastatic melanoma specimens compared to carcinoma or sarcoma specimens (P<0.0001). The expression of Dicer was significantly higher in melanomas compared to benign melanocytic nevi (P<0.0001). In patients with cutaneous melanomas, Dicer up-regulation was found to be significantly associated with an increased tumor mitotic index (P?=?0.04), Breslow's depth of invasion (P?=?0.03), nodal metastasis (P?=?0.04) and a higher American Joint Committee on Caner (AJCC) clinical stage (P?=?0.009). Using western blot analysis, we confirmed the cell-specific up-regulation of Dicer protein in vitro. A pooled-analysis on mRNA profiling in cutaneous tumors showed up-regulation of Dicer at the RNA level in cutaneous melanoma, also showing deregulation of other enzymes that participate in the biogenesis and maturation of canonical miRNAs. Conclusions Increased Dicer expression may be a clinically useful biomarker for patients with cutaneous melanoma. Understanding deregulation of Dicer and its influence on miRNA maturation is needed to predict the susceptibility of melanoma patients to miRNA-based therapy in the future. PMID:21698147

  17. Mechanism of catalase activity in aqueous solutions of dimanganese(III,IV) ethylenediamine-N,N prime -diacetate

    SciTech Connect

    Rush, J.D.; Maskos, Z. )

    1990-03-07

    Manganous ions, ligated by ethylenediamine-N,N{prime}-diacetate (edda = L) decompose hydrogen peroxide with a rate law {minus}d(H{sub 2}O{sub 2})/dt = k{sub 17}(Mn(edda))(H{sub 2}O{sub 2}) where k{sub 17} = 5.4 M{sup {minus}1} s{sup {minus}1} at pH 7. The reduction of peroxide to water is initiated by the reaction of Mn{sup II}L with a dinuclear Mn{sup III,IV}L{sub 2}. A subsequent fast reaction between the transient product of this reaction and hydrogen peroxide or tert-butyl hydroperoxide effectively oxidizes Mn(II) to Mn(IV) in a concerted step without formation of the hydroxyl radical. The green mixed-valence complex, which is probably a bis({mu}-oxo)-bridged structure, is stable in neutral aqueous solution and exhibits a 16-line ESR signal in frozen solution. The basis of catalase activity is the autocatalytic formation of this complex when hydrogen peroxide is reduced by manganese(II). The catalase cycle is independent of the formation of oxy radicals. Mononuclear Mn{sup III}edda and Mn{sup II}edda react with superoxide radicals, but the decomposition of peroxide is virtually independent of these reactions. In unbuffered solutions, with a moderate excess of hydrogen peroxide, an oscillation in the concentration of the dinuclear complex is detected. 28 refs., 10 figs., 5 tabs.

  18. Engineering of chimeric catalase-Angiopep-2 for intracellular protection of brain endothelial cells against oxidative stress.

    PubMed

    Yainoy, Sakda; Houbloyfa, Patcharaporn; Eiamphungporn, Warawan; Isarankura-Na-Ayudhya, Chartchalerm; Prachayasittikul, Virapong

    2014-07-01

    Blood-brain barrier (BBB) disruption and brain microvascular endothelial cells (BMVECs) death caused by excessive production of hydrogen peroxide (H2O2) have been implicated in several neurological conditions. To overcome this problem, H2O2-degrading enzyme with ability to enter the BMVECs is required. In the present study, genetic fusion of gene encoding human catalase and gene encoding Angiopep-2 (AP2), a brain targeting peptide, was performed. The fusion protein was successfully expressed in Escherichia coli and purified to homogeneity. The protein retained heme content and specific enzymatic activity in the same order of magnitude as that of native enzyme. Study of the BMVECs internalization showed that 0.1?M of the fusion protein can enter the cell within 15min, while internalization of the native protein was not observed at this condition. In addition, treatment of the BMVECs with 20 units of the fusion protein for 30min showed protection against H2O2 up to 5.0mM, whereas this protective effect was not observed from treatment with the native protein. Therefore, construction of chimeric human catalase and AP2 provides an insight into the development of potential therapeutic antioxidant with ability to penetrate the BBB for protection against neurodegenerative disorders. PMID:24769213

  19. Selective peracetic acid determination in the presence of hydrogen peroxide using a label free enzymatic method based on catalase.

    PubMed

    Galbán, Javier; Sanz, Vanesa; de Marcos, Susana

    2010-11-01

    Peracetic acid (PAA) is selectively determined in the presence of hydrogen peroxide (H(2)O(2)) by using the self-indicating UV-Vis molecular absorption properties of catalase. The PAA reacts with the protein giving an intermediate (Cat-I) which is reduced back by the amino acid core surrounding the heme group. Since the original form of the enzyme and the Cat-I have different UV-Vis absorption properties, the absorbance changes can be used for PAA determination. The H(2)O(2)/catalase reaction is extremely fast so that neither Cat-I compound nor kinetic interferences are observed. The method permits PAA determination in the 5 × 10(-7) to 1.5 × 10(-5) M range, the reproducibility being between 1% and 10%. Using this method, PAA has been successfully determined in water samples treated with commercial PAA/H(2)O(2) biocides. A theoretical study has also been carried out for obtaining a mathematical model able to analytically describe the process. PMID:20824427

  20. Triadimefon pretreatment protects newly assembled membrane system and causes up-regulation of stress proteins in salinity stressed Amaranthus lividus L. during early germination.

    PubMed

    Bhattacharjee, Soumen

    2008-09-01

    Imposition of salinity stress during early germination imposes a secondary oxidative stress in 120-hr-old Amaranthus lividus seedlings (measured in terms of accumulation of reactive oxygen species, antioxidative defense system and oxidative membrane lipid and protein damages). Seeds of Amaranthus when treated with triadimefon along with NaCI salinity significantly enhanced the activities of catalase, peroxidase and superoxide dismutase, compared to untreated salinity stressed 5-day-old seedlings. Triadimefon treatment also reduced the accumulation of both the ROS (H2O2 and O2*-) in 5-day-old Amaranthus seedlings. When oxidative membrane damages were estimated for triadimefon treated and salinity stressed juvenile seedlings and compared with untreated salinity stressed seedlings, it shows a clear reversal in oxidative membrane damages induced by triadimefon under salinity stress. Triadimefon treatment significantly reduces the membrane lipid peroxidation and the loss of membrane protein thiol level in salinity stressed Amaranthus seedlings. That triadimefon treatment under salinity stress restores the membrane integrity and improves the post-germinative seedling growth could be supported by the data of membrane injury index (MII), relative leakage ratio (RLR), membrane permeability status (MPS), relative growth index (RGI) and mean tolerance index (MTI). SDS-PAGE of total extractible proteins revealed that some new proteins were synthesized in triadimefon treated and salinity stressed seedlings as compared to untreated and salinity stressed one. However the most remarkable feature is the up-regulation of some of the stress proteins in triadimefon treated and salinity stressed seedlings. So, it appears that significant extent of salinity tolerance exhibited by triadimefon pretreated Amaranthus seedlings could be related to the mitigation of oxidative damage to the newly assembled membrane system of juvenile tissues as well as synthesis and up-regulation of stress proteins that enhanced salinity tolerance. PMID:19295087

  1. Aberrant Upregulation of Astroglial Ceramide Potentiates Oligodendrocyte Injury

    PubMed Central

    Kim, SunJa; Steelman, Andrew J.; Zhang, Yumin; Kinney, Hannah C.; Li, Jianrong

    2015-01-01

    Oligodendroglial injury is a pathological hallmark of many human white matter diseases, including multiple sclerosis and periventricular leukomalacia. Critical regulatory mechanisms of oligodendroglia destruction, however, remain incompletely understood. Ceramide, a bioactive sphingolipid pivotal to sphingolipid metabolism pathways, regulates cell death in response to diverse stimuli and has been implicated in neurodegenerative disorders. We report here that ceramide accumulates in reactive astrocytes in active lesions of multiple sclerosis and periventricular leukomalacia, as well as in animal models of demyelination. Serine palmitoyltransferase, the rate-limiting enzyme for ceramide de novo biosynthesis, was consistently upregulated in reactive astrocytes in the cuprizone mouse model of demyelination. Mass spectrometry confirmed the upregulation of specific ceramides during demyelination and revealed a concomitant increase of sphingosine as well as a suppression of sphingosine-1-phosphate, a potent signaling molecule with key roles in cell survival and mitogenesis. Importantly, this altered sphingolipid metabolism during demyelination was restored upon active remyelination. In culture, ceramide acted synergistically with tumor necrosis factor leading to apoptotic death of oligodendroglia in an astrocyte-dependent manner. Taken together, our findings implicate that disturbed sphingolipid pathways in reactive astrocytes may indirectly contribute to oligodendroglial injury in cerebral white matter disorders. PMID:21615590

  2. Upregulation of decorin by FXR in vascular smooth muscle cells

    SciTech Connect

    He Fengtian; Zhang Qiuhong; Kuruba, Ramalinga; Gao Xiang; Li Jiang; Li Yong; Gong Wei; Jiang, Yu; Xie Wen; Li Song

    2008-08-08

    Decorin is a member of the family of small leucine-rich proteoglycans that are present in blood vessels and synthesized by vascular smooth muscle cells (VSMCs). Decorin plays complex roles in both normal vascular physiology and the pathogenesis of various types of vascular disorders. However, the mechanisms of regulation of decorin expression in vasculature are not clearly understood. Particularly little information is available about a role of nuclear receptors in the regulation of decorin expression. In the present study, we report that activation of vascular FXR by a specific ligand resulted in upregulation of decorin at the levels of both mRNA and protein. FXR appears to induce decorin expression at a transcriptional level because (1) upregulation of decorin mRNA expression was abolished by the treatment of a transcription inhibitor, actinomycin D; and (2) decorin promoter activity was significantly increased by activation of FXR. Functional analysis of human decorin promoter identified an imperfect inverted repeat DNA motif, IR8 (-2313TGGTCAtagtgtcaTGACCT-2294), as a likely FXR-responsive element that is involved in decorin regulation.

  3. Upregulation of Phosphodiesterase type 5 in the Hyperplastic Prostate

    PubMed Central

    Zhang, Wenhao; Zang, Ning; Jiang, Yaoming; Chen, Ping; Wang, Xinghuan; Zhang, Xinhua

    2015-01-01

    Both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) are common in the aging male. Numerous clinical trials have demonstrated the efficacy and safety of phosphodiesterase type 5 inhibitors (PDE5-Is) for treating LUTS/BPH with/without ED. However, the influence of BPH on prostatic PDE5 expression has never been studied. A testosterone-induced rat model of BPH was developed and human hyperplastic prostate specimens were harvested during cystoprostatectomy. PDE5, nNOS, eNOS and ?1-adrenoreceptor subtypes (?1aARs, ?1bARs and ?1dARs) were determined with real-time RT-PCR for rat tissues whilst PDE5 and ?1-adrenoreceptor subtypes were determined in human samples. PDE5 was further analyzed with Western-blot and histological examination. Serum testosterone was measured with ELISA. The rat BPH model was validated as having a significantly enlarged prostate. PDE5 localized mainly in fibromuscular stroma in prostate. Our data showed a significant and previously undocumented upregulation of PDE5 in both rat and human BPH, along with increased expression of nNOS and ?1dARs for rat tissues and ?1aARs for human BPH. The upregulation of PDE5 in the hyperplastic prostate could explain the mechanism and contribute to the high effectiveness of PDE5-Is for treating LUTS/BPH. Fibromuscular stroma could be the main target for PDE5-Is within prostate. PMID:26657792

  4. FRZB up-regulated in hepatocellular carcinoma bone metastasis

    PubMed Central

    Huang, Jia; Hu, Wenhao; Lin, Xiangjin; Wang, Xuanwei; Jin, Ketao

    2015-01-01

    The clinical relevance of frizzled-related protein (FRZB) in hepatocellular carcinoma (HCC) bone metastasis remains uncertain. The aim of this study was to assess the clinical relationship of FRZB in patients with HCC bone metastasis after surgical resection. FRZB expression was evaluated by immunohistochemistry in formalin-fixed paraffin embedded (FFPE) HCC and paired bone metastasis tissues from 13 patients that underwent surgical resection. The clinical characteristics of 13 HCC patients with synchronous or metachronous bone metastasis received surgery were retrospectively reviewed. We found that FRZB was positive in 9 HCC tissues (69.2%) and in 11 paired bone metastatic tissues (84.6%) among these 13 paired samples. The expression of FRZB in the bone metastases was noticeably higher than that in the paired HCC tissues. The expression of FRZB was up-regulated in 10 (76.9%) paired bone metastases tissues. FRZB expression was up-regulated in HCC bone metastasis tissue, which suggested that FRZB might play a key role in the HCC bone metastasis. PMID:26722540

  5. Three-phase partitioning as a rapid and easy method for the purification and recovery of catalase from sweet potato tubers (Solanum tuberosum).

    PubMed

    Duman, Yonca Avc?; Kaya, Erdem

    2013-07-01

    Three-phase partitioning (TPP) was used to purify and recover catalase from potato crude extract. The method consists of ammonium sulfate saturation, t-butanol addition, and adjustment of pH, respectively. The best catalase recovery (262 %) and 14.1-fold purification were seen in the interfacial phase in the presence of 40 % (w/v) ammonium sulfate saturation with 1.0:1.0 crude extract/t-butanol ratio (v/v) at pH 7 in a single step. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the enzyme showed comparatively purification and protein molecular weight was nearly found to be 56 kDa. This study shows that TPP is a simple, economical, and quick method for the recovering of catalase and can be used for the purification process. PMID:23640263

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

    PubMed

    Kavakç?o?lu, Berna; Tarhan, Leman

    2014-10-01

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

  7. Purification, biochemical characterization, and implications of an alkali-tolerant catalase from the spacecraft-associated and oxidation-resistant Acinetobacter gyllenbergii 2P01AA.

    PubMed

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

    2015-04-01

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

  8. Extraction of superoxide dismutase, catalase, and carbonic anhydrase from stroma-free red blood cell hemolysate for the preparation of the nanobiotechnological complex of polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase.

    PubMed

    Guo, C; Gynn, M; Chang, T M S

    2015-06-01

    We report a novel method to simultaneously extract superoxide dismutase (SOD), catalase (CAT), and carbonic anhydrase (CA) from the same sample of red blood cells (RBCs). This avoids the need to use expensive commercial enzymes, thus enabling a cost-effective process for large-scale production of a nanobiotechnological polyHb-SOD-CAT-CA complex, with enhancement of all three red blood cell functions. An optimal concentration of phosphate buffer for ethanol-chloroform treatment results in good recovery of CAT, SOD, and CA after extraction. Different concentrations of the enzymes can be used to enhance the activity of polyHb-SOD-CAT-CA to 2, 4, or 6 times that of RBC. PMID:25961364

  9. Spectroscopic and kinetic investigation of the reactions of peroxyacetic acid with Burkholderia pseudomallei catalase-peroxidase, KatG.

    PubMed

    Ivancich, Anabella; Donald, Lynda J; Villanueva, Jacylyn; Wiseman, Ben; Fita, Ignacio; Loewen, Peter C

    2013-10-15

    Catalase-peroxidases or KatGs can utilize organic peroxyacids and peroxides instead of hydrogen peroxide to generate the high-valent ferryl-oxo intermediates involved in the catalase and peroxidase reactions. In the absence of peroxidatic one-electron donors, the ferryl intermediates generated with a low excess (10-fold) of peroxyacetic acid (PAA) slowly decay to the ferric resting state after several minutes, a reaction that is demonstrated in this work by both stopped-flow UV-vis absorption measurements and EPR spectroscopic characterization of Burkholderia pseudomallei KatG (BpKatG). EPR spectroscopy showed that the [Fe(IV)?O Trp330(•+)], [Fe(IV)?O Trp139(•)], and [Fe(IV)?O Trp153(•)] intermediates of the peroxidase-like cycle of BpKatG ( Colin, J. Wiseman, B. Switala, J. Loewen, P. C. Ivancich, A. ( 2009 ) J. Am. Chem. Soc. 131 , 8557 - 8563 ), formed with a low excess of PAA at low temperature, are also generated with a high excess (1000-fold) of PAA at room temperature. However, under high excess conditions, there is a rapid conversion to a persistent [Fe(IV)?O] intermediate. Analysis of tryptic peptides of BpKatG by mass spectrometry before and after treatment with PAA showed that specific tryptophan (including W330, W139, and W153), methionine (including Met264 of the M-Y-W adduct), and cysteine residues are either modified with one, two, or three oxygen atoms or could not be identified in the spectrum because of other undetermined modifications. It was concluded that these oxidized residues were the source of electrons used to reduce the excess of PAA to acetic acid and return the enzyme to the ferric state. Treatment of BpKatG with PAA also caused a loss of catalase activity towards certain substrates, consistent with oxidative disruption of the M-Y-W adduct, and a loss of peroxidase activity, consistent with accumulation of the [Fe(IV)?O] intermediate and the oxidative modification of the W330, W139, and W153. PAA, but not H2O2 or tert-butyl hydroperoxide, also caused subunit cross-linking. PMID:24044787

  10. Prognostic implication of neuropilin-1 upregulation in human nasopharyngeal carcinoma

    PubMed Central

    2013-01-01

    Objective As a receptor for both vascular endothelial growth factors and semaphorin, neuropilin-1 (NRP-1) is reported to be up-regulated in cells of several cancers. However, its roles in human nasopharyngeal carcinoma (NPC) are still unclear. Therefore, the goal of this study was to investigate the expression pattern of NRP-1 in NPC tissues, to clarify the clinical significance of NRP-1 expression in NPC as well as the potential prognostic implication of NRP-1 expression. Methods Immunohistochemistry was performed to detect the expression of NRP-1 in tumor tissue samples from 266 NPC patients. The association of NRP-1 protein expression with the clinicopathological characteristics and the prognosis of NPC were subsequently assessed. Results Immunohistochemical analysis showed that 176 of 266 (66.17%) paraffin-embedded archival NPC biopsies showed high expression of NRP-1, but no non-cancerous nasopharyngeal specimens showed positive expression of NRP-1. In addition, high NRP-1 expression was significantly associated with advanced clinical stage (P?=?0.02), positive recurrence (P?=?0.001) and metastasis status (P?=?0.001) of NPC. Moreover, the NPC patients with higher NRP-1 expression had shorter overall survival, whereas patients with lower NRP-1 expression had better survival (P?upregulation may be a novel biomarker for the prediction of advanced tumor progression and unfavorable prognosis in NPC patients who may benefit from alternative treatment strategy and targeted treatment. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1507827881105018. PMID:24053763

  11. Polymer-Induced Heteronucleation for Protein Single Crystal Growth: Structural Elucidation of Bovine Liver Catalase and Concanavalin A Forms

    SciTech Connect

    Foroughi, Leila M.; Kang, You-Na; Matzger, Adam J.

    2012-05-09

    Obtaining single crystals for X-ray diffraction remains a major bottleneck in structural biology; when existing crystal growth methods fail to yield suitable crystals, often the target rather than the crystallization approach is reconsidered. Here we demonstrate that polymer-induced heteronucleation, a powerful technique that has been used for small molecule crystallization form discovery, can be applied to protein crystallization by optimizing the heteronucleant composition and crystallization formats for crystallizing a wide range of protein targets. Applying these advances to two benchmark proteins resulted in dramatically increased crystal size, enabling structure determination, for a half century old form of bovine liver catalase (BLC) that had previously only been characterized by electron microscopy, and the discovery of two new forms of concanavalin A (conA) from the Jack bean and accompanying structural elucidation of one of these forms.

  12. Electron pathways in catalase and peroxidase enzymic catalysis. Metal and macrocycle oxidations of iron porphyrins and chlorins

    SciTech Connect

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

    1981-02-11

    Charge iterative extended Hueckel calculations are presented for compound II, the one-electron oxidation intermediate of horseradish peroxidase (HRP), and for compounds I, the two-electron oxidation transients of HRP and catalase (CAT) observed in the catalytic cycles of the hydroperoxidase enzymes. Compound II is described in terms of a ferryl configuration (O = Fe/sup IV/), and compounds I are described as ferrylporphyrin ..pi..-cation radicals. The validity of the iron ..pi..-cation calculations is supported by favorable comparison of parallel computations for porphyrin ..pi.. cations of diamagnetic metals with new and previously reported ESR results for radicals of zinc tetrabenz-, meso-tetramethyl, (/sup 14/N and /sup 15/N) tetraphenyl-, and magnesium (/sup 1/H and /sup 2/H) octaethylporphyrins. The calculated electronic configurations and unpaired spin density profiles for the ferryl ..pi.. cations satisfactorily account for the physical properties reported for compounds I of HRP (in the native protoporphyrin IX form or reconstituted with deuteroporphyrin), chloroperoxidase, and CAT. The ground states of the ..pi.. cations, a/sub 1u/ or a/sub 2u/, are determined by peripheral substitution and axial ligation, and the axial ligand of CAT I is predicted to differ from that of HRP I. The combination of model studies and calculations suggests that /sup 2/H, /sup 13/C, and /sup 15/N NMR studies of isotopically substituted proto and deutero HRP I would confirm the electronic profiles predicted. /sup 15/N NMR in particular would clearly discriminate between a/sub 1u/ and a/sub 2u/ configurations. As an additional test of the ferryl ..pi..-cation hypothesis, calculations are presented for a proposed ferrylchlorin ..pi.. cation of Neurospora crassa catalase, which contains an iron chlorin prosthetic group. Compound I of this unusual heme is predicted to occupy an a/sub 2/ ground state with the spin distribution and optical spectra reported here for synthetic chlorin radicals.

  13. A natural xanthone increases catalase activity but decreases NF-kappa B and lipid peroxidation in U-937 and HepG2 cell lines.

    PubMed

    Sahoo, Binay K; Zaidi, Adeel H; Gupta, Pankaj; Mokhamatam, Raveendra B; Raviprakash, Nune; Mahali, Sidhartha K; Manna, Sunil K

    2015-10-01

    Mangiferin, a C-glycosyl xanthone, has shown anti-inflammatory, antioxidant, and anti-tumorigenic activities. In the present study, we investigated the molecular mechanism for the antioxidant property of mangiferin. Considering the role of nuclear transcription factor kappa B (NF-?B) in inflammation and tumorigenesis, we hypothesized that modulating its activity will be a viable therapeutic target in regulating the redox-sensitive ailments. Our results show that mangiferin blocks several inducers, such as tumor necrosis factor (TNF), lypopolysaccharide (LPS), phorbol-12-myristate-13-acetate (PMA) or hydrogen peroxide (H2O2) mediated NF-?B activation via inhibition of reactive oxygen species generation. In silico docking studies predicted strong binding energy of mangiferin to the active site of catalase (-9.13 kcal/mol), but not with other oxidases such as myeloperoxidase, glutathione peroxidase, or inducible nitric oxide synthase. Mangiferin increased activity of catalase by 44%, but had no effect on myeloperoxidase activity in vitro. Fluorescence spectroscopy further revealed the binding of mangiferin to catalase at the single site with binding constant and binding affinity of 3.1×10(-7) M(-1) and 1.046 respectively. Mangiferin also inhibits TNF-induced lipid peroxidation and thereby protects apoptosis. Hence, mangiferin with its ability to inhibit NF-?B and increase the catalase activity may prove to be a potent therapeutic. PMID:26209362

  14. Coexpressed Catalase Protects Chimeric Antigen Receptor-Redirected T Cells as well as Bystander Cells from Oxidative Stress-Induced Loss of Antitumor Activity.

    PubMed

    Ligtenberg, Maarten A; Mougiakakos, Dimitrios; Mukhopadhyay, Madhura; Witt, Kristina; Lladser, Alvaro; Chmielewski, Markus; Riet, Tobias; Abken, Hinrich; Kiessling, Rolf

    2016-01-15

    Treatment of cancer patients by adoptive T cell therapy has yielded promising results. In solid tumors, however, T cells encounter a hostile environment, in particular with increased inflammatory activity as a hallmark of the tumor milieu that goes along with abundant reactive oxygen species (ROS) that substantially impair antitumor activity. We present a strategy to render antitumor T cells more resilient toward ROS by coexpressing catalase along with a tumor specific chimeric Ag receptor (CAR) to increase their antioxidative capacity by metabolizing H2O2. In fact, T cells engineered with a bicistronic vector that concurrently expresses catalase, along with the CAR coexpressing catalase (CAR-CAT), performed superior over CAR T cells as they showed increased levels of intracellular catalase and had a reduced oxidative state with less ROS accumulation in both the basal state and upon activation while maintaining their antitumor activity despite high H2O2 levels. Moreover, CAR-CAT T cells exerted a substantial bystander protection of nontransfected immune effector cells as measured by CD3? chain expression in bystander T cells even in the presence of high H2O2 concentrations. Bystander NK cells, otherwise ROS sensitive, efficiently eliminate their K562 target cells under H2O2-induced oxidative stress when admixed with CAR-CAT T cells. This approach represents a novel means for protecting tumor-infiltrating cells from tumor-associated oxidative stress-mediated repression. PMID:26673145

  15. Singlet oxygen treatment of tumor cells triggers extracellular singlet oxygen generation, catalase inactivation and reactivation of intercellular apoptosis-inducing signaling?

    PubMed Central

    Riethmüller, Michaela; Burger, Nils; Bauer, Georg

    2015-01-01

    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

  16. Simulated Microgravity Induces SOST/Sclerostin Upregulation in Osteocytes

    NASA Technical Reports Server (NTRS)

    Spatz, Jordan; Sibonga, Jean; Wu, Honglu; Barry, Kevin; Bouxsein, Mary; Pajevic, Paola Divieti

    2010-01-01

    Osteocytes are theorized to be the mechanosensors and transducers of mechanical forces in bone, yet the biological mechanism of this action remains elusive. Recent evidence suggests that SOST/Sclerostin is an important regulator of mechano-transduction. To investigate the molecular mechanisms of SOST/Sclerostin regulation under in-vitro and ex-vivo unloading we used the NASA Rotating Wall Vessel(RWV) Bioreactor. For in-vitro experiments, MLOY-4 osteocytic cells were seeded at a concentration of 250,000 cells onto 3D collagen scaffold (BD). Scaffolds (4 per condition) were either rotated in a vertical 50ml NASA/bioreactor vessel at 18 rpm (unloaded), cultured in a horizontal 50 ml NASA bioreactor vessel at 18 rpm (control for the sheared environment of vertical rotating vessel), or cultured in a static T-75 cm dish (static condition ) for 7days. For ex-vivo experiments, calvaria bones were harvested from 12-week old C57/Bl6 mice and sequentially digested with type I/II collagenase to remove periosteal osteoblasts. Calvaria halves (10 per condition) were then exposed to the same set of culture conditions described above. Simulated unloading, as achieved in the NASA RWV, resulted in enlarged, round osteocytes, as assessed by H&E staining, that was reminiscent of prior reports of unloading causing loss of osteocyte morphology and dendritic network connectivity. Semiquantitative realtime qPCR and immunohistochemistry from both in-vitro and ex-vivo RWV experiments demonstrated a four-fold up-regulation of SOST/Sclerostin. Furthermore, mRNA of the transcriptional SOST enhancer Mef2C was upregulated 1.4 fold in ex-vivo calvaria subjected to unloading conditions of the NASA RWV, suggesting that Mef2C might be an important regulator of mechano-sensation. These findings are consistent with results from seven day hindlimb unloading experiments, C57/B6 females, conducted in our laboratory and validate the use of the NASA RWV as a tool to study osteocyte mechanotransduction

  17. Identification of a member of the catalase multigene family on wheat chromosome 7A associated with flour b* colour and biological significance of allelic variation.

    PubMed

    Li, Dora A; Walker, Esther; Francki, Michael G

    2015-12-01

    Carotenoids (especially lutein) are known to be the pigment source for flour b* colour in bread wheat. Flour b* colour variation is controlled by a quantitative trait locus (QTL) on wheat chromosome 7AL and one gene from the carotenoid pathway, phytoene synthase, was functionally associated with the QTL on 7AL in some, but not all, wheat genotypes. A SNP marker within a sequence similar to catalase (Cat3-A1snp) derived from full-length (FL) cDNA (AK332460), however, was consistently associated with the QTL on 7AL and implicated in regulating hydrogen peroxide (H2O2) to control carotenoid accumulation affecting flour b* colour. The number of catalase genes on chromosome 7AL was investigated in this study to identify which gene may be implicated in flour b* variation and two were identified through interrogation of the draft wheat genome survey sequence consisting of five exons and a further two members having eight exons identified through comparative analysis with the single catalase gene on rice chromosome 6, PCR amplification and sequencing. It was evident that the catalase genes on chromosome 7A had duplicated and diverged during evolution relative to its counterpart on rice chromosome 6. The detection of transcripts in seeds, the co-location with Cat3-A1snp marker and maximised alignment of FL-cDNA (AK332460) with cognate genomic sequence indicated that TaCat3-A1 was the member of the catalase gene family associated with flour b* colour variation. Re-sequencing identified three alleles from three wheat varieties, TaCat3-A1a, TaCat3-A1b and TaCat3-A1c, and their predicted protein identified differences in peroxisomal targeting signal tri-peptide domain in the carboxyl terminal end providing new insights into their potential role in regulating cellular H2O2 that contribute to flour b* colour variation. PMID:26134858

  18. Effects of the administration of a catalase inhibitor into the fourth cerebral ventricle on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke

    PubMed Central

    Valenti, Vitor E.; de Abreu, Luiz Carlos; Fonseca, Fernando L. A.; Adami, Fernando; Sato, Monica A.; Vanderlei, Luiz Carlos M.; Ferreira, Lucas Lima; Rodrigues, Luciano M.; Ferreira, Celso

    2013-01-01

    OBJECTIVE: Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke. METHODS: Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 ?g/kg, bolus) and a depressor dose of sodium nitroprusside (50 ?g/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 ?L) into the 4th V. RESULTS: Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p<0.05) to a greater extent in WKY rats exposed to sidestream cigarette smoke than in WKY rats exposed to fresh air. However, in spontaneously hypertensive rats, the effect of the catalase inhibitor treatment was stronger in the fresh air condition (p<0.05). CONCLUSION: Administration of a catalase inhibitor into the 4th V combined with exposure to sidestream cigarette smoke has a stronger effect in WKY rats than in SH rats. PMID:23778493

  19. Revealing mechanisms of selective, concentration-dependent potentials of 4-hydroxy-2-nonenal to induce apoptosis in cancer cells through inactivation of membrane-associated catalase.

    PubMed

    Bauer, Georg; Zarkovic, Neven

    2015-04-01

    Tumor cells generate extracellular superoxide anions and are protected against superoxide anion-mediated intercellular apoptosis-inducing signaling by the expression of membrane-associated catalase. 4-Hydroxy-2-nonenal (4-HNE), a versatile second messenger generated during lipid peroxidation, has been shown to induce apoptosis selectively in malignant cells. The findings described in this paper reveal the strong, concentration-dependent potential of 4-HNE to specifically inactivate extracellular catalase of tumor cells both indirectly and directly and to consequently trigger apoptosis in malignant cells through superoxide anion-mediated intercellular apoptosis-inducing signaling. Namely, 4-HNE caused apoptosis selectively in NOX1-expressing tumor cells through inactivation of their membrane-associated catalase, thus reactivating subsequent intercellular signaling through the NO/peroxynitrite and HOCl pathways, followed by the mitochondrial pathway of apoptosis. Concentrations of 4-HNE of 1.2 µM and higher directly inactivated membrane-associated catalase of tumor cells, whereas at lower concentrations, 4-HNE triggered a complex amplificatory pathway based on initial singlet oxygen formation through H2O2 and peroxynitrite interaction. Singlet-oxygen-dependent activation of the FAS receptor and caspase-8 increased superoxide anion generation by NOX1 and amplification of singlet oxygen generation, which allowed singlet-oxygen-dependent inactivation of catalase. 4-HNE and singlet oxygen cooperate in complex autoamplificatory loops during this process. The finding of these novel anticancer pathways may be useful for understanding the role of 4-HNE in the control of malignant cells and for the optimization of ROS-dependent therapeutic approaches including antioxidant treatments. PMID:25619142

  20. Morphine upregulates kappa-opioid receptors of human lymphocytes.

    PubMed

    Suzuki, S; Chuang, T K; Chuang, L F; Doi, R H; Chuang, R Y

    2001-01-01

    Opioids such as morphine are potent analgesic and addictive compounds. Chronic morphine use also induces immunomodulatory and immunosuppressive effects, as especially evident in HIV-infected patients. Morphine acts on the immune cells primarily through its binding to mu-opioid receptors on the plasma membrane. However, morphine modulation of immune functions still exists in mu-opioid receptor knockout mice, suggesting that in addition to the mu opioid receptors, morphine may also act by mechanisms mediated by either delta or kappa opioid receptors. To determine whether morphine activates kappa opioid receptors (KOR), a quantitative competitive RT-PCR procedure was utilized to quantify the KOR gene expression of morphine-treated cells. A segment of KOR transcript spanning the second extracellular loop, which has the reported dynorphin specificity, and the seventh transmembrane domain of the receptor was amplified from the total RNA of morphine-treated CEM x174 lymphocytes, along with a competitor molecule. The competitor was constructed by deleting a 33-nucleotide fragment from KOR. The results of the competitive RT/PCR indicated that CEM x174 cells expressed KOR mRNA constitutively, in the order of femto-grams. Treatment of 10 microM of morphine resulted in the up-regulation of KOR gene expression 24 hr post-treatment. The observed morphine effect could be reversed by treating the cells with either naloxone (a KOR-partially selective antagonist) or nor-Binaltorphimine (a KOR-selective antagonist). PMID:11727785

  1. Inhibitory effects of deferasirox on the structure and function of bovine liver catalase: a spectroscopic and theoretical study.

    PubMed

    Moradi, M; Divsalar, A; Saboury, A A; Ghalandari, B; Harifi, A R

    2015-01-01

    Deferasirox (DFX), as an oral chelator, is used for treatment of transfusional iron overload. In this study, we have investigated the effects of DFX as an iron chelator, on the function and structure of bovine liver catalase (BLC) by different spectroscopic methods of UV-visible, fluorescence, and circular dichroism (CD) at two temperatures of 25 and 37 °C. In vitro kinetic studies showed that DFX can inhibit the enzymatic activity in a competitive manner. KI value was calculated 39 nM according to the Lineweaver-Burk plot indicating a high rate of inhibition of the enzyme. Intrinsic fluorescence data showed that increasing the drug concentrations leads to a significant decrease in the intrinsic emission of the enzyme indicating a significant change in the three-dimensional environment around the chromophores of the enzyme structure. By analyzing the fluorescence quenching data, it was found that the BLC has two binding sites for DFX and the values of binding constant at 25 and 37 °C were calculated 1.7 × 10(7) and 3 × 10(7) M(-1), respectively. The static type of quenching mechanism is involved in the quenching of intrinsic emission of enzyme. The thermodynamic data suggest that hydrophobic interactions play a major role in the binding reaction. UV-vis spectroscopy results represented the changes in tryptophan (Trp) absorption and Soret band spectra, which indicated changes in Trp and heme group position caused by the drug binding. Also, CD data represented that high concentrations of DFX lead to a significant decreasing in the content of ?-sheet and random coil accompanied an increasing in ?-helical content of the protein. The molecular docking results indicate that docking may be an appropriate method for prediction and confirmation of experimental results and also useful for determining the binding mechanism of proteins and drugs. According to above results, it can be concluded that the DFX can chelate the Fe(III) on the enzyme active site leading to changes in the function and structure of catalase which can be considered as a side effect of this drug and consequently has an important role in hepatic complications and fibrosis. PMID:25586906

  2. Molecular Characterization of KatY (Antigen 5), a Thermoregulated Chromosomally Encoded Catalase-Peroxidase of Yersinia pestis

    PubMed Central

    Garcia, Emilio; Nedialkov, Yuri A.; Elliott, Jeffrey; Motin, Vladimir L.; Brubaker, Robert R.

    1999-01-01

    The first temperature-dependent proteins (expressed at 37°C, but not 26°C) to be identified in Yersinia pestis were antigens 3 (fraction 1), 4 (pH 6 antigen), and 5 (hereafter termed KatY). Antigens 3 and 4 are now established virulence factors, whereas little is known about KatY, except that it is encoded chromosomally, produced in abundance, possesses modest catalase activity, and is shared by Yersinia pseudotuberculosis, but not Yersinia enterocolitica. We report here an improved chromatographic method (DEAE-cellulose, calcium hydroxylapatite, and Sephadex G-150) that yields enzymatically active KatY (2,423 U/mg of protein). Corresponding mouse monoclonal antibody 1B70.1 detected plasminogen activator-mediated hydrolysis of KatY, and a polyclonal rabbit antiserum raised against outer membranes of Y. pestis was enriched for anti-KatY. A sequenced ?16-kb Y. pestis DNA insert of a positive pLG338 clone indicated that katY encodes an 81.4-kDa protein (pI 6.98) containing a leader sequence of 2.6 kDa; the deduced molecular mass and pI of processed KatY were 78.8 kDa and 6.43, respectively. A minor truncated variant (predicted molecular mass of 53.6 kDa) was also expressed. KatY is similar (39 to 59% identity) to vegetative bacterial catalase-peroxidases (KatG in Escherichia coli) and is closely related to plasmid-encoded KatP of enterohemorrhagic E. coli O157:H7 (75% identity). katY encoded a putative Ca2+-binding site, and its promoter contained three homologues to the consensus recognition sequence of the pCD-encoded transcriptional activator LcrF. rbsA was located upstream of katY, and cybB, cybC, dmsABC, and araD were mapped downstream. These genes are not linked to katG or katP in E. coli. PMID:10322012

  3. Cerebral adenosine A? receptors are upregulated in rodent encephalitis.

    PubMed

    Paul, Soumen; Khanapur, Shivashankar; Boersma, Wytske; Sijbesma, Jurgen W; Ishiwata, Kiichi; Elsinga, Philip H; Meerlo, Peter; Doorduin, Janine; Dierckx, Rudi A; van Waarde, Aren

    2014-05-15

    Adenosine A1 receptors (A1Rs) are implied in the modulation of neuroinflammation. Activation of cerebral A1Rs acts as a brake on the microglial response after traumatic brain injury and has neuroprotective properties in animal models of Parkinson's disease and multiple sclerosis. Neuroinflammatory processes in turn may affect the expression of A1Rs, but the available data is limited and inconsistent. Here, we applied an animal model of encephalitis to assess how neuroinflammation affects the expression of A1Rs. Two groups of animals were studied: Infected rats (n=7) were intranasally inoculated with herpes simplex virus-1 (HSV-1, 1 × 10(7) plaque forming units), sham-infected rats (n=6) received only phosphate-buffered saline. Six or seven days later, microPET scans (60 min with arterial blood sampling) were made using the tracer 8-dicyclopropyl-1-(11)C-methyl-3-propyl-xanthine ((11)C-MPDX). Tracer clearance from plasma and partition coefficient (K?/k? estimated from a 2-tissue compartment model fit) were not significantly altered after virus infection. PET tracer distribution volume calculated from a Logan plot was significantly increased in the hippocampus (+37%) and medulla (+27%) of virus infected rats. Tracer binding potential (k?/k? estimated from the model fit) was significantly increased in the cerebellum (+87%) and the medulla (+148%) which may indicate increased A1R expression. This was confirmed by immunohistochemical analysis showing a strong increase of A1R immunoreactivity in the cerebellum of HSV-1-infected rats. Both the quantitative PET data and immunohistochemical analysis indicate that A1Rs are upregulated in brain areas where active virus is present. PMID:24513151

  4. Upregulation of b-FGF receptor expression after carotid bypass.

    PubMed

    Brothers, T E; Robison, J G; Elliott, B M; Boggs, J M; Frankel, A E; Willingham, M C

    1995-01-01

    Basic fibroblast growth factor (b-FGF) appears to be an important positive modulator of the neointimal hyperplasia that occurs after prosthetic vascular graft implantation through its effects on vascular myointimal/smooth muscle cell migration and proliferation. The distribution and extent of b-FGF receptor (b-FGFR1) expression was compared using immunohistochemical techniques in normal porcine carotid arteries and at various times up to 6 weeks following implantation of small caliber prosthetic vascular grafts. At the time of graft harvest, specimens were infused with OCT medium at 100 mm Hg and rapidly frozen in liquid nitrogen. Transverse sections of the perianastomotic arterial tissues were labeled with primary mouse monoclonal antibody directed toward the extracellular domain of the receptor, followed by goat-anti mouse IgG and rabbit anti-goat IgG conjugated to horseradish peroxidase. The b-FGFR1-positive cells were identified by peroxidase activity within the Golgi complex of smooth muscle cells. Normal porcine carotid arteries showed no evidence of staining for b-FGFR1. However, at 6 weeks cells in the perianastomotic area clearly showed significant b-FGFR1 localization. Anti-muscle actin labeling confirmed these to be smooth muscle cells. The observed upregulation of b-FGFR1 expression supports the concept of positive feedback by cytokines as a contributing factor to the hyperplastic response of smooth muscle cells after prosthetic vascular graft implantation. This finding further supports a potential strategy to specifically target activated smooth muscle cells through use of mitotoxin therapy. PMID:7830402

  5. Oxidative stress upregulates the NMDA receptor on cerebrovascular endothelium.

    PubMed

    Betzen, Christian; White, Robin; Zehendner, Christoph M; Pietrowski, Eweline; Bender, Bianca; Luhmann, Heiko J; Kuhlmann, Christoph R W

    2009-10-15

    N-methyl-d-aspartate receptor (NMDA-R)-mediated oxidative stress has been implicated in blood-brain barrier (BBB) disruption in a variety of neuropathological diseases. Although some interactions between both phenomena have been elucidated, possible influences of reactive oxygen species (ROS) on the NMDA-R itself have so far been neglected. The objective of this study was to examine how the cerebroendothelial NMDA-R is affected by exposure to oxidative stress and to assess possible influences on BBB integrity. RT-PCR confirmed several NMDA-R subunits (NR1, NR2B-D) expressed in the bEnd3 cell line (murine cerebrovascular endothelial cells). NR1 protein expression after exposure to ROS was observed via in-cell Western. The functionality of the expressed NMDA-R was determined by measuring DiBAC fluorescence in ROS-preexposed cells upon stimulation with the specific agonist NMDA. Finally, the effects on barrier integrity were evaluated using the ECIS system to detect changes in monolayer impedance upon NMDA-R stimulation after exposure to ROS. The expression of NR1 significantly (p<0.001) increased 72 h after 30 min exposure to superoxide (+33.8+/-7.5%), peroxynitrite (+84.9+/-10.7%), or hydrogen peroxide (+92.8+/-7.6%), resulting in increased cellular response to NMDA-R stimulation and diminished monolayer impedance. We conclude that oxidative stress upregulates NMDA-R on cerebrovascular endothelium and thus heightens susceptibility to glutamate-induced BBB disruption. PMID:19660541

  6. Chemokine Expression is Upregulated in Chondrocytes in Diabetic Fracture Healing

    PubMed Central

    Alblowi, Jazia; Tian, Chen; Siqueira, Michelle F.; Kayal, Rayyan; McKenzie, Erin; Behl, Yugal; Gerstenfeld, Louis; Einhorn, Thomas A.; Graves, Dana T.

    2013-01-01

    Chemokines are thought to play an important role in several aspects of bone metabolism including the recruitment of leukocytes and the formation of osteoclasts. We investigated the impact of diabetes on chemokine expression in normal and diabetic fracture healing. Fracture of the femur was performed in streptozotocin-induced diabetic and matched normoglycemic control mice. Microarray analysis was carried out and chemokine mRNA levels in vivo were assessed. CCL4 were examined in fracture calluses by immunohistochemistry and the role of TNF in diabetes-enhanced expression was investigated by treatment of animals with the TNF-specific inhibitor, pegsunercept. In vitro studies were conducted with ATDC5 chondrocytes. Diabetes significantly upregulated mRNA levels of several chemokines in vivo including CCL4, CCL8, CCL6, CCL11, CCL20, CCL24, CXCL2, CXCL5 and chemokine receptors CCR5 and CXCR4. Chondrocytes were identified as a significant source of CCL4 and its expression in diabetic fractures was dependent on TNF in diabetic fractures (P<0.05). TNF-? significantly increased mRNA levels of several chemokines in vitro which were knocked down with FOXO1 siRNA (P<0.05). CCL4 expression at the mRNA and proteins levels was induced by FOXO1 over-expression and reduced by FOXO1 knockdown. The current studies point to the importance of TNF-? as a mechanism for diabetes enhanced chemokine expression by chondrocytes, which may contribute to the accelerated loss of cartilage observed in diabetic fracture healing. Moreover, in vitro results point to FOXO1 as a potentially important transcription factor in mediating this effect. PMID:23262028

  7. Upregulation of GPR109A in Parkinson’s Disease

    PubMed Central

    Wakade, Chandramohan; Chong, Raymond; Bradley, Eric; Thomas, Bobby; Morgan, John

    2014-01-01

    Background Anecdotal animal and human studies have implicated the symptomatic and neuroprotective roles of niacin in Parkinson’s disease (PD). Niacin has a high affinity for GPR109A, an anti-inflammatory receptor. Niacin is also thought to be involved in the regulation of circadian rhythm. Here we evaluated the relationships among the receptor, niacin levels and EEG night-sleep in individuals with PD. Methods and Findings GPR109A expression (blood and brain), niacin index (NAD-NADP ratio) and cytokine markers (blood) were analyzed. Measures of night-sleep function (EEG) and perceived sleep quality (questionnaire) were assessed. We observed significant up-regulation of GPR109A expression in the blood as well as in the substantia nigra (SN) in the PD group compared to age-matched controls. Confocal microscopy demonstrated co-localization of GPR109A staining with microglia in PD SN. Pro and anti-inflammatory cytokines did not show significant differences between the groups; however IL1-?, IL-4 and IL-7 showed an upward trend in PD. Time to sleep (sleep latency), EEG REM and sleep efficiency were different between PD and age-matched controls. Niacin levels were lower in PD and were associated with increased frequency of experiencing body pain and decreased duration of deep sleep. Conclusions The findings of associations among the GPR109A receptor, niacin levels and night-sleep function in individuals with PD are novel. Further studies are needed to understand the pathophysiological mechanisms of action of niacin, GPR109A expression and their associations with night-sleep function. It would be also crucial to study GPR109A expression in neurons, astrocytes, and microglia in PD. A clinical trial to determine the symptomatic and/or neuroprotective effect of niacin supplementation is warranted. PMID:25329911

  8. Physiological analyses indicate superoxide dismutase, catalase, and phytochelatins play important roles in Pb tolerance in Eremochloa ophiuroides.

    PubMed

    Li, Xi; Cen, Huameng; Chen, Youxiang; Xu, Siying; Peng, Lingli; Zhu, Hanmingyue; Li, Yiqiao

    2016-03-01

    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

  9. Kinetin increases chromium absorption, modulates its distribution, and changes the activity of catalase and ascorbate peroxidase in Mexican Palo Verde

    PubMed Central

    Zhao, Yong; Peralta-Videa, Jose R.; Lopez-Moreno, Martha L.; Ren, Minghua; Saupe, Geoffrey; Gardea-Torresdey, Jorge L

    2015-01-01

    This report shows, for the first time, the effectiveness of the phytohormone kinetin (KN) in increasing Cr translocation from roots to stems in Mexican Palo Verde. Fifteen-day-old seedlings, germinated in soil spiked with Cr(III) and (VI) at 60 and 10 mg kg?1, respectively, were watered every other day for 30 days with a KN solution at 250 ?M. Samples were analyzed for catalase (CAT) and ascorbate peroxidase (APOX) activities, Cr concentration, and Cr distribution in tissues. Results showed that KN reduced CAT but increased APOX in the roots of Cr(VI)-treated plants. In the leaves, KN reduced both CAT and APOX in Cr(III) but not in Cr(VI)-treated plants. However, KN increased total Cr concentration in roots, stems, and leaves by 45%, 103%, and 72%, respectively, compared to Cr(III) alone. For Cr(VI), KN increased Cr concentrations in roots, stems, and leaves, respectively, by 53%, 129%, and 168%, compared to Cr(VI) alone. The electron probe microanalyzer results showed that Cr was mainly located at the cortex section in the root, and Cr distribution was essentially homogenous in stems. However, proven through X-ray images, Cr(VI)-treated roots and stems had more Cr accumulation than Cr(III) counterparts. KN increased the Cr translocation from roots to stems. PMID:21174467

  10. In Vitro Effect of Sodium Fluoride on Malondialdehyde Concentration and on Superoxide Dismutase, Catalase, and Glutathione Peroxidase in Human Erythrocytes

    PubMed Central

    Gutiérrez-Salinas, José; García-Ortíz, Liliana; Morales González, José A.; Hernández-Rodríguez, Sergio; Ramírez-García, Sotero; Núñez-Ramos, Norma R.; Madrigal-Santillán, Eduardo

    2013-01-01

    The aim of this paper was to describe the in vitro effect of sodium fluoride (NaF) on the specific activity of the major erythrocyte antioxidant enzymes, as well as on the membrane malondialdehyde concentration, as indicators of oxidative stress. For this purpose, human erythrocytes were incubated with NaF (0, 7, 28, 56, and 100??g/mL) or NaF (100??g/mL) + vitamin E (1, 2.5, 5 and 10??g/mL). The malondialdehyde (MDA) concentration on the surface of the erythrocytes was determined, as were the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GlPx). Our results demonstrated that erythrocytes incubated with increasing NaF concentrations had an increased MDA concentration, along with decreased activity of antioxidant enzymes. The presence of vitamin E partially reversed the toxic effects of NaF on erythrocytes. These findings suggest that NaF induces oxidative stress in erythrocytes in vitro, and this stress is partially reversed by the presence of vitamin E. PMID:24223512

  11. Ascorbate Peroxidase and Catalase Activities and Their Genetic Regulation in Plants Subjected to Drought and Salinity Stresses

    PubMed Central

    Sofo, Adriano; Scopa, Antonio; Nuzzaci, Maria; Vitti, Antonella

    2015-01-01

    Hydrogen peroxide (H2O2), an important relatively stable non-radical reactive oxygen species (ROS) is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses). Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT), ascorbate peroxidases (APX), some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants. PMID:26075872

  12. Evaluation of the serum catalase and myeloperoxidase activities in chronic arsenic-exposed individuals and concomitant cytogenetic damage

    SciTech Connect

    Banerjee, Mayukh; Banerjee, Nilanjana; Ghosh, Pritha; Das, Jayanta K.; Basu, Santanu; Sarkar, Ajoy K.; States, J. Christopher; Giri, Ashok K.

    2010-11-15

    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.

  13. Effect of nutrition factors on the synthesis of superoxide dismutase, catalase, and membrane lipid peroxide levels in Cordyceps militaris mycelium.

    PubMed

    Wang, Zun-Sheng; Gu, Yu-Xiang; Yuan, Qin-Sheng

    2006-01-01

    Effect of carbon, nitrogen, and metal ion sources on superoxide dismutase (SOD), catalase (CAT) activities, and lipid perioxide (LPO) levels in Cordyceps militaris mycelium were investigated at stationary growth phase by step supplementing with these nutrition factors in shake-flask cultures. Mycelium was cultivated in several growth media containing different carbon sources. The observed highest SOD and CAT activities were 44.3 U/mg protein in the presence of 20% potato broth plus 2% glucose medium and 93.7 U/mg protein in presence of 20% potato broth plus 1% glucose medium, respectively. By supplementing with either yeast extract or tryptone in 0.1-0.5% concentration range, the highest SOD and CAT activities were 21.1 U/mg protein in medium supplemented with 0.1% yeast extract and 20.7 U/mg protein in medium supplemented with 0.1% tryptone, respectively. Supplementing with Cu(2+), Zn(2+), and Mn(2+) caused a stimulation of SOD synthesis. The minimum LPO level was observed at media presented Zn(2+). The time course of SOD and CAT biosynthesis showed two maxima, which correspond to the maximum of biomass. High SOD levels and low LPO levels in the medium described above indicated that the appropriate metal ions could provide a suitable protection for cells against oxygen radical damage. PMID:16392009

  14. Spectroscopic investigations on the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots on catalase

    NASA Astrophysics Data System (ADS)

    Sun, Haoyu; Yang, Bingjun; Cui, Erqian; Liu, Rutao

    2014-11-01

    Quantum dots (QDs) are recognized as some of the most promising semiconductor nanocrystals in biomedical applications. However, the potential toxicity of QDs has aroused wide public concern. Catalase (CAT) is a common enzyme in animal and plant tissues. For the potential application of QDs in vivo, it is important to investigate the interaction of QDs with CAT. In this work, the effect of N-Acetyl-L-cysteine-Capped CdTe Quantum Dots with fluorescence emission peak at 612 nm (QDs-612) on CAT was investigated by fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible (UV-vis) absorption and circular dichroism (CD) techniques. Binding of QDs-612 to CAT caused static quenching of the fluorescence, the change of the secondary structure of CAT and the alteration of the microenvironment of tryptophan residues. The association constants K were determined to be K288K = 7.98 × 105 L mol-1 and K298K = 7.21 × 105 L mol-1. The interaction between QDs-612 and CAT was spontaneous with 1:1 stoichiometry approximately. The CAT activity was also inhibited for the bound QDs-612. This work provides direct evidence about enzyme toxicity of QDs-612 to CAT in vitro and establishes a new strategy to investigate the interaction between enzyme and QDs at a molecular level, which is helpful for clarifying the bioactivities of QDs in vivo.

  15. Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.

    PubMed

    Nie, Qiong; Gao, Guo-Li; Fan, Qing-jie; Qiao, Guang; Wen, Xiao-Peng; Liu, Tao; Peng, Zhi-Jun; Cai, Yong-Qiang

    2015-05-25

    Abiotic stresses usually cause H2O2 accumulation, with harmful effects, in plants. Catalase may play a key protective role in plant cells by detoxifying this excess H2O2. Pitaya (Hylocereus undatus) shows broad ecological adaptation due to its high tolerance to abiotic stresses, e.g. drought, heat and poor soil. However, involvement of the pitaya catalase gene (HuCAT) in tolerance to abiotic stresses is unknown. In the present study, a full-length HuCAT3 cDNA (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

  16. Fenton reaction-mediated fluorescence quenching of N-acetyl-l-cysteine-protected gold nanoclusters: analytical applications of hydrogen peroxide, glucose, and catalase detection.

    PubMed

    Deng, Hao-Hua; Wu, Gang-Wei; He, Dong; Peng, Hua-Ping; Liu, Ai-Lin; Xia, Xing-Hua; Chen, Wei

    2015-10-26

    Given the importance of hydrogen peroxide (H2O2) in many biological processes and its wide application in various industries, the demand for sensitive, accurate, and economical H2O2 sensors is high. In this study, we used Fenton reaction-stimulated fluorescence quenching of N-acetyl-l-cysteine-protected gold nanoclusters (NAC-AuNCs) as a reporter system for the determination of H2O2. After the experimental conditions were optimized, the sensing platform enabled the analysis of H2O2 with a limit of detection (LOD) as low as 0.027 ?M. As the glucose oxidase cascade leads to the generation of H2O2 and catalase catalyzes the decomposition of H2O2, these two biocatalytic procedures can be probed by the Fenton reaction-mediated quenching of NAC-AuNCs. The LOD for glucose was found to be 0.18 ?M, and the linear range was 0.39-27.22 ?M. The LOD for catalase was 0.002 U mL(-1), and the linear range was 0.01-0.3 U mL(-1). Moreover, the proposed sensing methods were successfully applied for human serum glucose detection and the non-invasive determination of catalase activity in human saliva, demonstrating their great potential for practical applications. PMID:26436146

  17. Environmental Lead Exposure, Catalase Gene, and Markers of Antioxidant and Oxidative Stress Relation to Hypertension: An Analysis Based on the EGAT Study

    PubMed Central

    Kaojarern, Sukhumpun; Chanprasertyothin, Suwannee; Panpunuan, Pachara; Petchpoung, Krittaya; Tatsaneeyapant, Aninthita; Yoovathaworn, Krongtong; Sura, Thunyachai; Kaojarern, Sming; Sritara, Piyamit

    2015-01-01

    Lead has been linked to the development of hypertension via oxidative stress. Catalase plays an important role in the disposal of hydrogen peroxide in erythrocyte and its activity was determined by CAT gene. The aims of this study were to investigate (1) the association between blood levels of antioxidant markers such as catalase, superoxide dismutase, glutathione, glutathione peroxidase, oxidative stress-marker (malondialdehyde), and blood lead level and (2) the influence of genetic polymorphism of CAT gene (rs769217) on change in blood pressure in general population of EGAT study project. This is a cross-sectional study of 332 normotensive, 432 prehypertensive, and 222 hypertensive male subjects. Hypertensive subjects had significantly higher blood lead level (5.28??g/dL) compared to normotensive (4.41??g/dL) and prehypertensive (4.55??g/dL) subjects (P < 0.05). These significant findings are also found in MDA levels. Moreover, individuals with TT genotype in hypertensive group had significantly higher blood lead and MDA levels (6.06??g/dL and 9.67??mol/L) than those with CC genotype (5.32??g/dL and 8.31??mol/L, P < 0.05). Our findings suggested that decreased blood catalase activity in this polymorphism together with low level lead exposure induced lipid peroxidation may be responsible for hypertension. PMID:25793211

  18. Methamphetamine-Induced Degeneration of Dopaminergic Neurons Involves Autophagy and Upregulation of

    E-print Network

    Sulzer, David

    Methamphetamine-Induced Degeneration of Dopaminergic Neurons Involves Autophagy and Upregulation and Physiology, University of California, San Francisco, California 94143 Methamphetamine (METH) selectively producing oxyradical stress, autophagy, and neurite degeneration. Key words: methamphetamine; VMAT2

  19. Exercise training reverses age-induced inducible nitric oxide synthase upregulation 

    E-print Network

    Song, Wook

    2005-02-17

    NOS suggesting that delayed induction of iNOS may cause devastating damage to muscle and contribute to rhabdomyolysis (141). Inflammatory myopathies are also characterized by an upregulation of iNOS. In 21 patients with autoimmune inflammatory myopathies...

  20. Quercetin up-regulates mitochondrial complex-I activity to protect against programmed cell death in rotenone model of Parkinson's disease in rats.

    PubMed

    Karuppagounder, S S; Madathil, S K; Pandey, M; Haobam, R; Rajamma, U; Mohanakumar, K P

    2013-04-16

    We tested quercetin, a dietary bioflavonoid with potent free radical scavenging action and antioxidant activity, for its neuroprotective effects in rotenone-induced hemi-parkinsonian rats. Rats were infused unilaterally with rotenone into the substantia nigra, and quercetin (25-75mg/kg, i.p.) was administered at 12-h intervals for 4days, and analyzed on the 5th day. Amphetamine- or apomorphine-induced unilateral rotations were significantly reduced in quercetin-treated rats, when analyzed on 14th or 16th day post-surgery, respectively. Quercetin possessed potent hydroxyl radical scavenging action in a cells-free, Fenton-like reaction in test tubes, and in isolated mitochondria when measured by salicylate hydroxylation method. We observed dose-dependent attenuation of the rotenone-induced loss in striatal dopamine, and nigral oxidized and reduced glutathione, as well as the increases in endogenous antioxidant enzymes (catalase and superoxide dismutase) activities supporting the notion that quercetin-effect is mediated via its powerful hydroxyl radicals-scavenging and antioxidant actions. Quercetin's dose-dependent ability to up-regulate mitochondrial complex-I activity, as evidenced by NADH-oxidation, and as seen in blue native-polyacrylamide gel electrophoresis (PAGE) staining in both the contra- and ipsi-lateral nigra suggests the containment of reactive oxygen production at the mitochondrial level. Rotenone-induced induction of NADH-diaphorase activity in the nigral neurons, and its attenuation by quercetin pointed to the possible involvement of nitric oxide too. Reversal of neuronal death induced by rotenone as observed by increased tyrosine hydroxylase-positive cells and decreased TdT-mediated dUTP nick end-labeling (TUNEL) staining in the substantia nigra confirmed the potential of quercetin to revamp dopaminergic cells following oxidative stress mediated programmed cell death and neuronal demise. The present study strongly implicates quercetin's potential ability to repair mitochondrial electron transport defects and to up-regulate its function as the basis of neuroprotection observed in a mitochondrial neurotoxin-induced Parkinsonism. PMID:23357119

  1. [Application of visible/near-infrared spectroscopy to the determination of catalase and peroxidase content in barley leaves].

    PubMed

    Zhao, Yun; Zhang, Chu; Liu, Fei; Kong, Wen-Wen; He, Yong

    2014-09-01

    Visible/near-infrared spectroscopy was applied to determine the content of catalase (CAT) and peroxidase (POD) in barley leaves under the herbicide stress of propyl 4-(2-(4, 6-dimethoxypyrimidin-2-yloxy) benzylamino) benzoate (ZJ0273). The spectral data of the barley leaves in the range of 500-900 nm were preprocessed by moving average with 11 points. Seven outlier samples for CAT and 8 outlier samples for POD were detected and removed by Monte Carlo-partial least squares (MCPLS). PLS, least-squares support vector machine (LS-SVM) and extreme learning machine (ELM) models were built for both CAT and POD. ELM model obtained best results for CAT, with correlation coefficient of calibration (Rc) of 0.916 and correlation co-efficient of prediction (Rp) of 0.786. PLS model obtained best prediction results for POD, with Rc of 0.984 and Rp of 0.876. Successive projections algorithm (SPA) was applied to select 8 and 19 effective wavelengths for CAT and POD, respectively. PLS, LS-SVM and ELM models were built using the selected effective wavelengths of CAT and POD. ELM model performed best for CAT and POD prediction, with Rc of 0.928 and Rp of 0.790 for CAT and Rp of 0.965 and Rp of 0.941 for POD. The prediction results using the full spectral data and the effective wavelengths were quite close, and the prediction performance for POD was much better than the prediction performance for CAT, and the studies should be further explored to build more precise and more robust models for CAT and POD determination. The overall results indicated that it was feasible to use visible/near-infrared spectroscopy for CAT and POD content determination in barley leaves under the stress of ZJ0273. PMID:25532330

  2. 3{prime} UTR sequence-specific mRNA-protein complexes and the post-transcriptional regulation of catalase

    SciTech Connect

    Reimer, D.L.; Ott, R.N.; Singh, S.M.

    1994-09-01

    Recently, sequences in the 3{prime} untranslated region (3{prime} UTR) of some genes have been recognized which may play an important role in the post-transcriptional regulation of gene expression. Mutations in this region of the gene are known to cause at least two diseases including myotonic dystrophy and a lysosomal accumulation disease. The mechanism is thought to involve mRNA-protein interactions that affect translation and/or mRNA stability. Reports of this nature are not common and the significance of the often large 3{prime} UTR on the regulation of gene expression remains speculative. Studies on the 3{prime} UTR mRNA-protein interactions in model eukaryotic genes therefore are critical to better understand the molecular mechanisms involved in post-transcriptional gene regulation. Mouse catalase, encoded by Cas-1, was used as a model to characterize the molecular mechanisms of post-transcriptional gene regulation. The 3{prime} UTR (752 bp) of Cas-1 contains three unusual, near repeats [(CA){sub 31}, (U){sub 15} and (TGTGC){sub 7}]. Gel mobility shift assays using {sup 32}P-labelled transcripts which contain these sequences and tissue homogenates from various sources identified mRNA-protein complexes specific to (CA){sub 31} and (U){sub 15} only. In all strains analyzed, a single protein of 69 kDa which was involved in the (CA){sub 31} complex, was observed in most tissues except lung and was localized to the polysomal fraction. Similarly, two proteins involved in the (U){sub 15} complex, 38 and 47 kDa, were observed in all tissues and strains studied. Only the 38 kDa protein was observed in the polysomal fraction. The results argue for a possible role for these 3{prime} UTR mRNA-binding protein complexes in the post-transcriptional regulation of this antioxidant enzyme.

  3. Roles of Mn-catalase and a possible heme peroxidase homologue in protection from oxidative stress in Thermus thermophilus.

    PubMed

    Ebihara, Akio; Manzoku, Miho; Fukui, Kenji; Shimada, Atsuhiro; Morita, Rihito; Masui, Ryoji; Kuramitsu, Seiki

    2015-07-01

    Hydrogen peroxide (H2O2) produces hydroxyl radicals that directly attack a variety of biomolecules and cause severe cellular dysfunction. An extremely thermophilic bacterium, Thermus thermophilus HB8, possesses at least three enzymes that can scavenge H2O2: manganese-containing catalase (TTHA0122, MnCAT), a possible peroxiredoxin homologue (TTHA1300), and a possible heme peroxidase (HPX) homologue (TTHA1714). To investigate the roles of these proteins, we attempted to disrupt each of these genes in T. thermophilus HB8. Although we were able to completely disrupt ttha1300, we were unable to completely delete ttha0122 and ttha1714 because of polyploidy. Quantitative real-time PCR showed that, compared to the wild type, 31 % of ttha0122 and 11 % of ttha1714 remained in the ?ttha0122 and ?ttha1714 disruption mutants, respectively. Mutants with reduced levels of ttha0122 or ttha1714 exhibited a significant increase in spontaneous mutation frequency. ?ttha1714 grew slower than the wild type under normal conditions. ?ttha0122 grew very poorly after exposure to H2O2. Moreover, ?ttha0122 did not show H2O2-scavenging activity, whereas ?ttha1300 and ?ttha1714 scavenged H2O2, a property similar to that exhibited by the wild type. MnCAT purified from T. thermophilus HB8 cells scavenged H2O2 in vitro. The recombinant form of the possible HPX homologue, reconstituted with hemin, showed peroxidase activity with H2O2 as an oxidant substrate. Based on these results, we propose that not only MnCAT but also the possible HPX homologue is involved in protecting the cell from oxidative stress in T. thermophilus. PMID:25997395

  4. The involvement of nuclear factor-?appaB in the nuclear targeting and cyclin E1 upregulating activities of hepatoma upregulated protein.

    PubMed

    Chen, Jo-Mei Maureen; Chiu, Shao-Chih; Wei, Tong-You Wade; Lin, Shin-Yi; Chong, Cheong-Meng; Wu, Chi-Chen; Huang, Jiao-Ying; Yang, Shu-Ting; Ku, Chia-Feng; Hsia, Jiun-Yi; Yu, Chang-Tze Ricky

    2015-01-01

    Hepatoma upregulated protein (HURP) is originally isolated during the search for the genes associated with hepatoma. HURP is upregulated in many human cancers. Culture cells exhibit transformed and invasive phenotype when ectopic HURP is introduced, revealing HURP as an oncogene candidate. Our previous studies demonstrated that Aurora-A regulated the cell transforming activities of HURP by phosphorylating HURP at four serines. To unravel how the Aurora-A/HURP cascade contributes to cell transformation, we firstly noticed that HURP shuttled between cytoplasm and nucleus. The nuclear localization activity of HURP was promoted or abolished by overexpression or knockdown of Aurora-A. Similarly, the HURP phosphorylation mimicking mutant 4E had higher nuclear targeting activity than the phosphorylation deficient mutant 4A. The HURP 4E accelerated G1 progression and upregulated cyclin E1, and the cyclin E1 upregulating and cell transforming activities of HURP were diminished when the nuclear localization signal (NLS) was removed from HURP. Furthermore, HURP employed p38/nuclear factor-?B (NF-?B) cascade to stimulate cell growth. Interestingly, NF-?B trapped HURP in nucleus by interacting with HURP 4E. At last, the HURP/NF-?B complex activated the cyclin E1 promoter. Collectively, Aurora-A/HURP relays cell transforming signal to NF-?B, and the HURP/NF-?B complex is engaged in the regulation of cyclin E1 expression. PMID:25289861

  5. Bilirubin inhibits the up-regulation of inducible nitric oxide synthase by scavenging reactive oxygen species generated by the toll-like receptor 4-dependent activation of NADPH oxidase

    PubMed Central

    Idelman, Gila; Smith, Darcey L.H.; Zucker, Stephen D.

    2015-01-01

    It has been previously shown that bilirubin prevents the up-regulation of inducible nitric oxide synthase (iNOS) in response to LPS. The present study examines whether this effect is exerted through modulation of Toll-Like Receptor-4 (TLR4) signaling. LPS-stimulated iNOS and NADPH oxidase (Nox) activity in RAW 264.7 murine macrophages was assessed by measuring cellular nitrate and superoxide (O2?) production, respectively. The generation of both nitrate and O2? in response to LPS was suppressed by TLR4 inhibitors, indicating that activation of iNOS and Nox is TLR4-dependent. While treatment with superoxide dismutase (SOD) and bilirubin effectively abolished LPS-mediated O2? production, hydrogen peroxide and nitrate release were inhibited by bilirubin and PEG-catalase, but not SOD, supporting that iNOS activation is primarily dependent upon intracellular H2O2. LPS treatment increased nuclear translocation of the redox-sensitive transcription factor Hypoxia Inducible Factor-1? (HIF-1?), an effect that was abolished by bilirubin. Cells transfected with murine iNOS reporter constructs in which the HIF-1?-specific hypoxia response element was disrupted exhibited a blunted response to LPS, supporting that HIF-1? mediates Nox-dependent iNOS expression. Bilirubin, but not SOD, blocked the cellular production of interferon-?, while interleukin-6 production remained unaffected. These data support that bilirubin inhibits the TLR4-mediated up-regulation of iNOS by preventing activation of HIF-1? through scavenging of Nox-derived reactive oxygen species. Bilirubin also suppresses interferon-? release via a ROS-independent mechanism. These findings characterize potential mechanisms for the anti-inflammatory effects of bilirubin. PMID:26163808

  6. Hypoxia up-regulates SERPINB3 through HIF-2? in human liver cancer cells

    PubMed Central

    Paternostro, Claudia; Biasiolo, Alessandra; Colombatto, Sebastiano; Cambieri, Irene; Quarta, Santina; Novo, Erica; Morello, Elisabetta; Villano, Gianmarco; Fasolato, Silvano; Musso, Tiziana; David, Ezio; Tusa, Ignazia; Rovida, Elisabetta; Autelli, Riccardo; Smedile, Antonina; Cillo, Umberto; Pontisso, Patrizia; Parola, Maurizio

    2015-01-01

    SERPINB3 is a cysteine-proteases inhibitor up-regulated in a significant number of cirrhotic patients carrying hepatocellular carcinoma (HCC) and recently proposed as a prognostic marker for HCC early recurrence. SERPINB3 has been reported to stimulate proliferation, inhibit apoptosis and, similar to what reported for hypoxia, to trigger epithelial-to-mesenchymal transition (EMT) and increased invasiveness in liver cancer cells. This study has investigated whether SERPINB3 expression is regulated by hypoxia-related mechanisms in liver cancer cells. Exposure of HepG2 and Huh7 cells to hypoxia up-regulated SERPINB3 transcription, protein synthesis and release in the extracellular medium. Hypoxia-dependent SERPINB3 up-regulation was selective (no change detected for SERPINB4) and operated through hypoxia inducible factor (HIF)-2? (not HIF-1?) binding to SERPINB3 promoter, as confirmed by chromatin immuno-precipitation assay and silencing experiments employing specific siRNAs. HIF-2?-mediated SERPINB3 up-regulation under hypoxic conditions required intracellular generation of ROS. Immuno-histochemistry (IHC) and transcript analysis, performed in human HCC specimens, revealed co-localization of the two proteins in liver cancer cells and the existence of a positive correlation between HIF-2? and SERPINB3 transcript levels, respectively. Hypoxia, through HIF-2?-dependent and redox-sensitive mechanisms, up-regulates the transcription, synthesis and release of SERPINB3, a molecule with a high oncogenic potential. PMID:25544768

  7. Mechanisms of Hypoxic Up-Regulation of Versican Gene Expression in Macrophages

    PubMed Central

    Sotoodehnejadnematalahi, Fattah; Staples, Karl J.; Chrysanthou, Elvina; Pearson, Helen; Ziegler-Heitbrock, Loems; Burke, Bernard

    2015-01-01

    Hypoxia is a hallmark of many pathological tissues. Macrophages accumulate in hypoxic sites and up-regulate a range of hypoxia-inducible genes. The matrix proteoglycan versican has been identified as one such gene, but the mechanisms responsible for hypoxic induction are not fully characterised. Here we investigate the up-regulation of versican by hypoxia in primary human monocyte-derived macrophages (HMDM), and, intriguingly, show that versican mRNA is up-regulated much more highly (>600 fold) by long term hypoxia (5 days) than by 1 day of hypoxia (48 fold). We report that versican mRNA decay rates are not affected by hypoxia, demonstrating that hypoxic induction of versican mRNA is mediated by increased transcription. Deletion analysis of the promoter identified two regions required for high level promoter activity of luciferase reporter constructs in human macrophages. The hypoxia-inducible transcription factor HIF-1 has previously been implicated as a key potential regulator of versican expression in hypoxia, however our data suggest that HIF-1 up-regulation is unlikely to be principally responsible for the high levels of induction observed in HMDM. Treatment of HMDM with two distinct specific inhibitors of Phosphoinositide 3-kinase (PI3K), LY290042 and wortmannin, significantly reduced induction of versican mRNA by hypoxia and provides evidence of a role for PI3K in hypoxic up-regulation of versican expression. PMID:26057378

  8. Exogenous Proline and Glycine Betaine Mediated Upregulation of Antioxidant Defense and Glyoxalase Systems Provides Better Protection against Salt-Induced Oxidative Stress in Two Rice (Oryza sativa L.) Varieties

    PubMed Central

    Hasanuzzaman, Mirza; Alam, Md. Mahabub; Rahman, Anisur; Hasanuzzaman, Md.; Nahar, Kamrun; Fujita, Masayuki

    2014-01-01

    The present study investigates the roles of exogenous proline (Pro, 5?mM) and glycine betaine (GB, 5?mM) in improving salt stress tolerance in salt sensitive (BRRI dhan49) and salt tolerant (BRRI dhan54) rice (Oryza sativa L.) varieties. Salt stresses (150 and 300?mM NaCl for 48?h) significantly reduced leaf relative water (RWC) and chlorophyll (chl) content and increased endogenous Pro and increased lipid peroxidation and H2O2 levels. Ascorbate (AsA), glutathione (GSH) and GSH/GSSG, ascorbate peroxidae (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), catalase (CAT), and glyoxalase I (Gly I) activities were reduced in sensitive variety and these were increased in tolerant variety due to salt stress. The glyoxalase II (Gly II), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities were increased in both cultivars by salt stress. Exogenous Pro and GB application with salt stress improved physiological parameters and reduced oxidative damage in both cultivars where BRRI dhan54 showed better tolerance. The result suggests that exogenous application of Pro and GB increased rice seedlings' tolerance to salt-induced oxidative damage by upregulating their antioxidant defense system where these protectants rendered better performance to BRRI dhan54 and Pro can be considered as better protectant than GB. PMID:24991566

  9. Relations between occupational exposure to coal mine dusts, erythrocyte catalase and Cu++/Zn++ superoxide dismutase activities, and the severity of coal workers' pneumoconiosis

    PubMed Central

    Nadif, R.; Bourgkard, E.; Dusch, M.; Bernadac, P.; Bertrand, J. P.; Mur, J. M.; Pham, Q. T.

    1998-01-01

    OBJECTIVES: To better understand the relations between occupational exposure, blood antioxidant enzyme activities, total plasma antioxidant concentration, and the severity of coal workers' pneumoconiosis (CWP). METHODS: Blood samples were obtained from miners without CWP exposed to low dust concentrations for > or = 4 years at the time of the study (n = 105), or exposed to high dust concentrations for > or = 14 years at the time of the study (n = 58), and from retired miners with CWP (n = 19). Miners without CWP were classified into three subgroups according to their estimated cumulative exposure to dust. Chest x ray films were obtained for each miner. Miners were classified in five subgroups according to their International Labour Organisation (ILO) profusion grades. Univariate tests were completed by multiple linear regression analyses. RESULTS: The estimated cumulative exposure to dust was strongly positively related to erythrocyte catalase activity and strongly negatively related to Cu++/Zn++ SOD activity only in miners exposed to high dust concentrations for > or = 14 years at the time of the study (F tests p = 0.006 and p = 0.004 respectively). Moreover, catalase activity was strongly related to the severity of CWP expressed as five subgroups of ILO profusion grades (F test p = 0.003); the greatest difference in the mean values was found between the group of 1/1 to 1/2 ILO profusion grades and the group of 2/1 to 3/3 ILO profusion grades. CONCLUSION: These results are in good agreement with the hypothesis that production of reactive oxygen species may be an important event in the exposure to coal mine dusts and the severity of CWP. Erythrocyte catalase and Cu++/Zn++ SOD activities are more closely related to recent exposure to high dust concentrations than to cumulative exposure, and could be considered as biological markers of exposure rather than as markers of early adverse biological effect.   PMID:9849540

  10. Evidence for an Ionic Intermediate in the Transformation of Fatty Acid Hydroperoxide by a Catalase-related Allene Oxide Synthase from the Cyanobacterium Acaryochloris marina*

    PubMed Central

    Gao, Benlian; Boeglin, William E.; Zheng, Yuxiang; Schneider, Claus; Brash, Alan R.

    2009-01-01

    Allene oxides are reactive epoxides biosynthesized from fatty acid hydroperoxides by specialized cytochrome P450s or by catalase-related hemoproteins. Here we cloned, expressed, and characterized a gene encoding a lipoxygenase-catalase/peroxidase fusion protein from Acaryochloris marina. We identified novel allene oxide synthase (AOS) activity and a by-product that provides evidence of the reaction mechanism. The fatty acids 18.4?3 and 18.3?3 are oxygenated to the 12R-hydroperoxide by the lipoxygenase domain and converted to the corresponding 12R,13-epoxy allene oxide by the catalase-related domain. Linoleic acid is oxygenated to its 9R-hydroperoxide and then, surprisingly, converted ?70% to an epoxyalcohol identified spectroscopically and by chemical synthesis as 9R,10S-epoxy-13S-hydroxyoctadeca-11E-enoic acid and only ?30% to the 9R,10-epoxy allene oxide. Experiments using oxygen-18-labeled 9R-hydroperoxide substrate and enzyme incubations conducted in H218O indicated that ?72% of the oxygen in the epoxyalcohol 13S-hydroxyl arises from water, a finding that points to an ionic intermediate (epoxy allylic carbocation) during catalysis. AOS and epoxyalcohol synthase activities are mechanistically related, with a reacting intermediate undergoing a net hydrogen abstraction or hydroxylation, respectively. The existence of epoxy allylic carbocations in fatty acid transformations is widely implicated although for AOS reactions, without direct experimental support. Our findings place together in strong association the reactions of allene oxide synthesis and an ionic reaction intermediate in the AOS-catalyzed transformation. PMID:19531485

  11. Combustion products of 1,3-butadiene inhibit catalase activity and induce expression of oxidative DNA damage repair enzymes in human bronchial epithelial cells.

    PubMed

    Kennedy, Christopher H; Catallo, W James; Wilson, Vincent L; Mitchell, James B

    2009-10-01

    1,3-Butadiene, an important petrochemical, is commonly burned off when excess amounts need to be destroyed. This combustion process produces butadiene soot (BDS), which is composed of a complex mixture of polycyclic aromatic hydrocarbons in particulates ranging in size from <1 microm to 1 mm. An organic extract of BDS is both cytotoxic and genotoxic to normal human bronchial epithelial (NHBE) cells. Based on the oxidizing potential of BDS, we hypothesized that an organic extract of this particulate matter would (1) cause enzyme inactivation due to protein amino acid oxidation and (2) induce oxidative DNA damage in NHBE cells. Thus, our aims were to determine the effect of butadiene soot ethanol extract (BSEE) on both enzyme activity and the expression of proteins involved in the repair of oxidative DNA damage. Catalase was found to be sensitive to BDS as catalase activity was potently diminished in the presence of BSEE. Using Western analysis, both the alpha isoform of human 8-oxoguanine DNA glycosylase (alpha-hOGG1) and human apurinic/apyrimidinic endonuclease (APE-1) were shown to be significantly overexpressed as compared to untreated controls after exposure of NHBE cells to BSEE. Our results indicate that BSEE is capable of effectively inactivating the antioxidant enzyme catalase, presumably via oxidation of protein amino acids. The presence of oxidized biomolecules may partially explain the extranuclear fluorescence that is detected when NHBE cells are treated with an organic extract of BDS. Overexpression of both alpha-hOGG1 and APE-1 proteins following treatment of NHBE cells with BSEE suggests that this mixture causes oxidative DNA damage. PMID:18685817

  12. Immobilization of catalase on electrospun PVA/PA6-Cu(II) nanofibrous membrane for the development of efficient and reusable enzyme membrane reactor.

    PubMed

    Feng, Quan; Zhao, Yong; Wei, Anfang; Li, Changlong; Wei, Qufu; Fong, Hao

    2014-09-01

    In this study, a mat/membrane consisting of overlaid PVA/PA6-Cu(II) composite nanofibers was prepared via the electrospinning technique followed by coordination/chelation with Cu(II) ions; an enzyme of catalase (CAT) was then immobilized onto the PVA/PA6-Cu(II) nanofibrous membrane. The amount of immobilized catalase reached a high value of 64 ± 4.6 mg/g, while the kinetic parameters (Vmax and Km) of enzyme were 3774 ?mol/mg·min and 41.13 mM, respectively. Furthermore, the thermal stability and storage stability of immobilized catalase were improved significantly. Thereafter, a plug-flow type of immobilized enzyme membrane reactor (IEMR) was assembled from the PVA/PA6-Cu(II)-CAT membrane. With the increase of operational pressure from 0.02 to 0.2 MPa, the flux value of IEMR increased from 0.20 ± 0.02 to 0.76 ± 0.04 L/m(2)·min, whereas the conversion ratio of H2O2 decreased slightly from 92 ± 2.5% to 87 ± 2.1%. After 5 repeating cycles, the production capacity of IEMR was merely decreased from 0.144 ± 0.006 to 0.102 ± 0.004 mol/m(2)·min. These results indicated that the assembled IEMR possessed high productivity and excellent reusability, suggesting that the IEMR based on electrospun PVA/PA6-Cu(II) nanofibrous membrane might have great potential for various applications, particularly those related to environmental protection. PMID:25093534

  13. Structural and dynamical properties of manganese catalase and the synthetic protein DF1 and their implication for reactivity from classical molecular dynamics calculations.

    PubMed

    Spiegel, Katrin; De Grado, William F; Klein, Michael L

    2006-11-01

    There is a pressing need for accurate force fields to assist in metalloprotein analysis and design. Recent work on the design of mimics of dimetal proteins highlights the requirements for activity. DF1 is a de novo designed protein, which mimics the overall fold and active site geometry of a series of diiron and dimanganese proteins. Specifically, the dimanganese form of DF1 is a mimic of the natural enzyme manganese catalase, which catalyzes the dismutation reaction of hydrogen peroxide into water and oxygen. During catalytic turnover, the active site has to accommodate both the reduced and the oxidized state of the dimanganese core. The biomimetic protein DF1 is only stable in the reduced form and thus not active. Furthermore, the synthetic protein features an additional bridging glutamate sidechain, which occupies the substrate binding site. The goal of this study is to develop classical force fields appropriate for design of such important dimanganese proteins. To this aim, we use a nonbonded model to represent the metal-ligand interactions, which implicitly takes into account charge transfer and local polarization effects between the metal and its ligands. To calibrate this approach, we compare and contrast geometric and dynamical properties of manganese catalase and DF1. Having demonstrated a good correspondence with experimental structural data, we examine the effect of mutating the bridging glutamate to aspartate (M1) and serine (M2). Classical MD based on the refined forcefield shows that these point mutations affect not only the immediate coordination sphere of the manganese ions, but also the relative position of the helices, improving the similarity to Mn-catalase, especially in case of M2. On the basis of these findings, classical molecular dynamics calculations with the active site parameterization scheme introduced herein seem to be a promising addition to the protein design toolbox. PMID:16917908

  14. Identification of Scedosporium boydii catalase A1 gene, a reactive oxygen species detoxification factor highly expressed in response to oxidative stress and phagocytic cells.

    PubMed

    Mina, Sara; Staerck, Cindy; d'Almeida, Sènan M; Marot, Agnès; Delneste, Yves; Calenda, Alphonse; Tabiasco, Julie; Bouchara, Jean-Philippe; Fleury, Maxime J J

    2015-12-01

    Scedosporium boydii is an opportunistic filamentous fungus which may be responsible for a large variety of infections in both immunocompetent and immunocompromised individuals. This fungus belongs to the Scedosporium apiospermum species complex which usually ranks second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF). Species of the S. apiospermum complex are able to chronically colonize the CF airways suggesting pathogenic mechanisms allowing persistence and growth of these fungi in the respiratory tract. Few putative virulence factors have been purified and characterized so far in the S. apiospermum complex including a cytosolic Cu,Zn-superoxide dismutase (SOD) and a monofunctional catalase (catalase A1). Upon microbial infection, host phagocytes release reactive oxygen species (ROS), such as hydrogen peroxide, as part of the antimicrobial response. Catalases are known to protect pathogens against ROS by degradation of the hydrogen peroxide. Here, we identified the S. boydii catalase A1 gene (CATA1) and investigated its expression in response to the environmental conditions encountered in the CF airways and to the oxidative stress. Results showed that S. boydii CATA1 gene expression is not affected by hypoxia, hypercapnia or pH changes. In contrast, CATA1 gene was overexpressed in response to a chemically induced oxidative stress with a relative gene expression 37-fold higher in the presence of 250 ?M H2O2, 20-fold higher with 250 ?M menadione and 5-fold higher with 2 mM paraquat. Moreover, S. boydii CATA1 gene expression progressively increased upon exposure to activated THP-1-derived macrophages, reaching a maximum after 12 h (26 fold). Activated HL60-derived neutrophils and activated human peripheral blood neutrophils more rapidly induced S. boydii CATA1 gene overexpression, a maximum gene expression level being reached at 75 min (17 fold) and 60 min (15 fold), respectively. In contrast expression of the gene encoding the Cu,Zn-SOD (SODC gene) was not affected by H2O2, menadione, paraquat or in co-culture with phagocytic cells. These results suggest that S. boydii CATA1 gene is highly stimulated by the oxidative burst response whereas SODC gene is constitutively expressed. PMID:26615753

  15. Epigenetic upregulation of endogenous VEGF-A reduces myocardial infarct size in mice.

    PubMed

    Turunen, Mikko P; Husso, Tiia; Musthafa, Haja; Laidinen, Svetlana; Dragneva, Galina; Laham-Karam, Nihay; Honkanen, Sanna; Paakinaho, Anne; Laakkonen, Johanna P; Gao, Erhe; Vihinen-Ranta, Maija; Liimatainen, Timo; Ylä-Herttuala, Seppo

    2014-01-01

    "Epigenetherapy" alters epigenetic status of the targeted chromatin and modifies expression of the endogenous therapeutic gene. In this study we used lentiviral in vivo delivery of small hairpin RNA (shRNA) into hearts in a murine infarction model. shRNA complementary to the promoter of vascular endothelial growth factor (VEGF-A) was able to upregulate endogenous VEGF-A expression. Histological and multiphoton microscope analysis confirmed the therapeutic effect in the transduced hearts. Magnetic resonance imaging (MRI) showed in vivo that the infarct size was significantly reduced in the treatment group 14 days after the epigenetherapy. Importantly, we show that promoter-targeted shRNA upregulates all isoforms of endogenous VEGF-A and that an intact hairpin structure is required for the shRNA activity. In conclusion, regulation of gene expression at the promoter level is a promising new treatment strategy for myocardial infarction and also potentially useful for the upregulation of other endogenous genes. PMID:24587164

  16. Antidepressants upregulate messenger RNA levels of the neuroprotective enzyme superoxide dismutase (SOD1).

    PubMed Central

    Li, X M; Chlan-Fourney, J; Juorio, A V; Bennett, V L; Shrikhande, S; Bowen, R C

    2000-01-01

    OBJECTIVE: To investigate the effect of amitriptyline, bupropion, doxepin or venlafaxine on the gene expression of the neuroprotective enzyme superoxide dismutase (SOD1) in a catecholamine cell in vitro model. DESIGN: Molecular study of a cultured cell line. INTERVENTIONS: Rat pheochromocytoma (PC12) cells were incubated in 1 and 10 mumol/L of various antidepressant medications for 24 or 48 hours. OUTCOME MEASURES: Northern blot analysis. RESULTS: Amitriptyline up-regulated SOD1 messenger RNA in a time- and dose-dependent manner. The greatest up-regulation was following incubation with 10 mumol/L amitriptyline for 48 hours. The addition of bupropion, doxepin or venlafaxine to PC12 cell cultures also up-regulated SOD1 mRNA. CONCLUSIONS: These findings suggest that some antidepressants have the ability to positively regulate neuroprotective genes. Images Fig. 2 PMID:10721683

  17. Basic fibroblast growth factor induces miR-134 upregulation in astrocyte for cell maturation.

    PubMed

    Numakawa, Tadahiro; Nakajima, Shingo; Yamamoto, Noriko; Ooshima, Yoshiko; Odaka, Haruki; Hashido, Kazuo; Adachi, Naoki; Kunugi, Hiroshi

    2015-01-01

    Evidence suggests that neuronal microRNAs (miRs) contribute to synaptic plasticity, although a role of glial miRs have been unknown. Growth factors including brain-derived neurotrophic factor (BDNF) regulate neuronal functions via upregulation of miRs, while possible influences on expression/function of glial miRs have not been fully understood. Here, we report that basic fibroblast growth factor (bFGF) increased miR-134 expression in astrocyte. The miR-134 was upregulated through stimulating extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling, because inhibitors for each signaling blocked the miR-134 induction by bFGF. We also found upregulation of glial fibrillary acidic protein (astrocyte marker) and decreased extracellular concentration of glutamate after miR-134 overexpression and bFGF application, suggesting that astroglial cell maturation is enhanced by bFGF through induction of miR-134. PMID:25482448

  18. Epigenetic Upregulation of Endogenous VEGF-A Reduces Myocardial Infarct Size in Mice

    PubMed Central

    Musthafa, Haja; Laidinen, Svetlana; Dragneva, Galina; Laham-Karam, Nihay; Honkanen, Sanna; Paakinaho, Anne; Laakkonen, Johanna P.; Gao, Erhe; Vihinen-Ranta, Maija; Liimatainen, Timo; Ylä-Herttuala, Seppo

    2014-01-01

    “Epigenetherapy” alters epigenetic status of the targeted chromatin and modifies expression of the endogenous therapeutic gene. In this study we used lentiviral in vivo delivery of small hairpin RNA (shRNA) into hearts in a murine infarction model. shRNA complementary to the promoter of vascular endothelial growth factor (VEGF-A) was able to upregulate endogenous VEGF-A expression. Histological and multiphoton microscope analysis confirmed the therapeutic effect in the transduced hearts. Magnetic resonance imaging (MRI) showed in vivo that the infarct size was significantly reduced in the treatment group 14 days after the epigenetherapy. Importantly, we show that promoter-targeted shRNA upregulates all isoforms of endogenous VEGF-A and that an intact hairpin structure is required for the shRNA activity. In conclusion, regulation of gene expression at the promoter level is a promising new treatment strategy for myocardial infarction and also potentially useful for the upregulation of other endogenous genes. PMID:24587164

  19. Mu opioid receptor up-regulation and participation in excitability of hippocampal pyramidal cell electrophysiology

    SciTech Connect

    Moudy, A.M.

    1988-01-01

    Chronic administration of opiate antagonists to rats results in up-regulation of their brain opioid receptors. Using subcellular fractionation techniques, brain opioid receptors were resolved into two membrane populations, one associated with synaptic plasma membranes (SPM) and the other enriched in smooth endoplasmic reticulum and Golgi (microsomes). This study addressed in part the question of whether an antagonist induces up-regulation uniformly in these two populations. Rats were administered naltrexone by subcutaneously implanted osmotic minipumps. Forebrain mu receptor levels were determined by homologous displacement of ({sup 3}H)D-ala{sup 2}-mePhe{sup 4}-gly-ol{sup 5}-enkephalin (DAGO) followed by computer estimation of binding parameters. Receptor levels in crude membranes rose 77% after treatment. Microsomes displayed a 92% increase, a two-fold greater change than in SPMs (51%). These results establish that naltrexone induces up-regulation of both membrane populations; and that microsomal and SPM receptors represent discrete populations of intracellular and cell surface sites, respectively. Binding experiments on isolated hippocampi also demonstrated up-regulation (71%) of mu receptors. To demonstrate up-regulation of opioid receptors electrophysiologically, hippocampal slices were prepared from rats which had been chronically treated with naltrexone. After superfusion with DAGO, these slices showed a 42% greater population spike output than controls in response to the same EPSP input. Hippocampi from animals treated for two weeks showed an additional increase in sensitivity. The results support a disinhibitory role for opioids in pyramidal cell hyper-excitability. More importantly, they demonstrate a significant physiological correlate to opioid receptor up-regulation.

  20. SREBP-1 Mediates Angiotensin II-Induced TGF-?1 Upregulation and Glomerular Fibrosis.

    PubMed

    Wang, Tony N; Chen, Xing; Li, Renzhong; Gao, Bo; Mohammed-Ali, Zahraa; Lu, Chao; Yum, Victoria; Dickhout, Jeffrey G; Krepinsky, Joan C

    2015-08-01

    Angiotensin II is an important mediator of CKD of diverse etiology. A common pathologic feature of CKD is glomerular fibrosis, a central mediator of which is the profibrotic cytokine TGF-?. The mechanisms underlying the induction of TGF-? and matrix by angiotensin II are not completely understood. Recent studies showed that overexpression of the transcription factor SREBP-1 induces glomerular sclerosis and that angiotensin II can activate SREBP-1 in tubular cells. We thus studied whether SREBP-1 is activated by angiotensin II and mediates angiotensin II-induced profibrogenic responses in primary rat mesangial cells. Treatment of cells with angiotensin II induced the upregulation and activation of SREBP-1. Angiotensin II-induced activation of SREBP-1 required signaling through the angiotensin II type I receptor and activation of PI3K/Akt in addition to the chaperone SCAP and protease S1P. Notably, angiotensin II-induced endoplasmic reticulum stress was identified as a key mediator of Akt-SREBP-1 activation, and inhibition of endoplasmic reticulum stress or SREBP-1 prevented angiotensin II-induced SREBP-1 binding to the TGF-? promoter, TGF-? upregulation, and downstream fibronectin upregulation. Endoplasmic reticulum stress alone, however, did not induce TGF-? upregulation despite activating SREBP-1. Although not required for SREBP-1 activation by angiotensin II, EGF receptor signaling was necessary for activation of the SREBP-1 cotranscription factor Sp1, which provided a required second signal for TGF-? upregulation. In vivo, endoplasmic reticulum stress and SREBP-1-dependent effects were induced in glomeruli of angiotensin II-infused mice, and administration of the SREBP inhibitor fatostatin prevented angiotensin II-induced TGF-? upregulation and matrix accumulation. SREBP-1 and endoplasmic reticulum stress thus provide potential novel therapeutic targets for the treatment of CKD. PMID:25398788

  1. Peroxiredoxin-glutaredoxin and catalase promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidants and survival within neutrophil extracellular traps.

    PubMed

    Juneau, Richard A; Pang, Bing; Armbruster, Chelsie E; Murrah, Kyle A; Perez, Antonia C; Swords, W Edward

    2015-01-01

    Nontypeable Haemophilus influenzae (NTHI) is a common commensal and opportunistic pathogen of the human airways. For example, NTHI is a leading cause of otitis media and is the most common cause of airway infections associated with chronic obstructive pulmonary disease (COPD). These infections are often chronic/recurrent in nature and involve bacterial persistence within biofilm communities that are highly resistant to host clearance. Our previous work has shown that NTHI within biofilms has increased expression of factors associated with oxidative stress responses. The goal of this study was to define the roles of catalase (encoded by hktE) and a bifunctional peroxiredoxin-glutaredoxin (encoded by pdgX) in resistance of NTHI to oxidants and persistence in vivo. Isogenic NTHI strain 86-028NP mutants lacking hktE and pdgX had increased susceptibility to peroxide. Moreover, these strains had persistence defects in the chinchilla infection model for otitis media, as well as in a murine model for COPD. Additional work showed that pdgX and hktE were important determinants of NTHI survival within neutrophil extracellular traps (NETs), which we have shown to be an integral part of NTHI biofilms in vivo. Based on these data, we conclude that catalase and peroxiredoxin-glutaredoxin are determinants of bacterial persistence during chronic/recurrent NTHI infections that promote bacterial survival within NETs. PMID:25348637

  2. Comparison of Conventional and Molecular Methods for Identification of Aerobic Catalase-Negative Gram-Positive Cocci in the Clinical Laboratory

    PubMed Central

    Bosshard, P. P.; Abels, S.; Altwegg, M.; Böttger, E. C.; Zbinden, R.

    2004-01-01

    Over a period of 18 months we have evaluated the use of 16S ribosomal DNA (rDNA) sequence analysis as a means of identifying aerobic catalase-negative gram-positive cocci in the clinical laboratory. A total of 171 clinically relevant strains were studied. The results of molecular analyses were compared with those obtained with a commercially available phenotypic identification system (API 20 Strep system; bioMérieux sa, Marcy l'Etoile, France). Phenotypic characterization identified 67 (39%) isolates to the species level and 32 (19%) to the genus level. Seventy-two (42%) isolates could not be discriminated at any taxonomic level. In comparison, 16S rDNA sequencing identified 138 (81%) isolates to the species level and 33 (19%) to the genus level. For 42 of 67 isolates assigned to a species with the API 20 Strep system, molecular analyses yielded discrepant results. Upon further analysis it was concluded that among the 42 isolates with discrepant results, 16S rDNA sequencing was correct for 32 isolates, the phenotypic identification was correct for 2 isolates, and the results for 8 isolates remained unresolved. We conclude that 16S rDNA sequencing is an effective means for the identification of aerobic catalase-negative gram-positive cocci. With the exception of Streptococcus pneumoniae and beta-hemolytic streptococci, we propose the use of 16S rDNA sequence analysis if adequate species identification is of concern. PMID:15131171

  3. Fluctuations in peroxidase and catalase activities of resistant and susceptible black gram (Vigna mungo (L.) Hepper) genotypes elicited by Bemisia tabaci (Gennadius) feeding

    PubMed Central

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Sandhu, Jeet Singh

    2012-01-01

    Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae), is a serious pest of black gram, (Vigna mungo (L.) Hepper), an important legume pulse crop grown in north India. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to whitefly in nine black gram genotypes. Oxidative enzyme activity was estimated spectrophotometrically from leaf samples collected at 30 and 50 d after sowing (DAS) from whitefly infested and uninfested plants. The enzymes showed different activity levels at different times after the infestation. The results indicated that in general, whitefly infestation increased the activities of peroxidase and decreased the catalase activity. Resistant genotypes NDU 5-7 and KU 99-20 recorded higher peroxidase and catalase activities at 30 and 50 DAS under whitefly-stress conditions as compared with non-stressed plants. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of black gram plants against B. tabaci infestation. The potential mechanisms to explain the correlation of resistance to whitefly in black gram genotypes with higher activities of oxidative enzymes are also discussed. PMID:22902801

  4. Upregulation of cathepsin S in psoriatic keratinocytes Alexander Scho nefu1

    E-print Network

    Lübbert, Hermann

    skin biopsies, i.e. atopic dermatitis, actinic keratosis and psoriasis, CATS staining is strongly increased in the dermis. But only in psoriasis, CATS- immunostaining is also detectable in keratinocytes. We ­ psoriasis ­ T-cell Please cite this paper as: Upregulation of cathepsin S in psoriatic keratinocytes

  5. Cotton Benzoquinone Reductase: Up-regulation During Early Cotton Fiber Developement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzoquinone reductase (BR; EC 1.6.5.7) is an enzyme that catalyzes the bivalent redox reactions of quinones without the production of free radical intermediates. Using 2-D PAGE comparisons, two proteins were found to be up-regulated in wild-type cotton ovules during the fiber initiation stage but ...

  6. CD84 is markedly up-regulated in Kawasaki disease arteriopathy

    PubMed Central

    Reindel, R; Bischof, J; Kim, K-Y A; Orenstein, J M; Soares, M B; Baker, S C; Shulman, S T; Perlman, E J; Lingen, M W; Pink, A J; Trevenen, C; Rowley, A H

    2014-01-01

    The major goals of Kawasaki disease (KD) therapy are to reduce inflammation and prevent thrombosis in the coronary arteries (CA), but some children do not respond to currently available non-specific therapies. New treatments have been difficult to develop because the molecular pathogenesis is unknown. In order to identify dysregulated gene expression in KD CA, we performed high-throughput RNA sequencing on KD and control CA, validated potentially dysregulated genes by real-time reverse transcription–polymerase chain reaction (RT–PCR) and localized protein expression by immunohistochemistry. Signalling lymphocyte activation molecule CD84 was up-regulated 16-fold (P < 0·01) in acute KD CA (within 2 months of onset) and 32-fold (P < 0·01) in chronic CA (5 months to years after onset). CD84 was localized to inflammatory cells in KD tissues. Genes associated with cellular proliferation, motility and survival were also up-regulated in KD CA, and immune activation molecules MX2 and SP140 were up-regulated in chronic KD. CD84, which facilitates immune responses and stabilizes platelet aggregates, is markedly up-regulated in KD CA in patients with acute and chronic arterial disease. We provide the first molecular evidence of dysregulated inflammatory responses persisting for months to years in CA significantly damaged by KD. PMID:24635044

  7. INTEGRIN-MEDIATED CELL ATTACHMENT SHOWS TIME-DEPENDENT UPREGULATION OF GAP JUNCTION COMMUNICATION.

    EPA Science Inventory


    Integrin-mediated Cell Attachment Shows Time-Dependent Upregulation of Gap Junction
    Communication

    Rachel Grindstaff and Carl Blackman, National Health & Environmental Effects Research
    Laboratory, Office of Research and Development, US EPA, Research Triang...

  8. Sex differences in immunity and rapid upregulation of immune defence during parental care in the burying

    E-print Network

    Sakaluk, Scott

    Sex differences in immunity and rapid upregulation of immune defence during parental care the carcass with anal exudates that have been shown to serve an antimicrobial function (social immunity sensu Behavioral Ecology, 21, 663­668). We examined the effect of sex, mating and parental care on measurements

  9. Up-regulation of the Neuronal Nicotinic Receptor 7 by HIV Glycoprotein 120

    E-print Network

    Lasalde Dominicc, Jose A. - Department of Biology, Universidad de Puerto Rico

    Up-regulation of the Neuronal Nicotinic Receptor 7 by HIV Glycoprotein 120 POTENTIAL IMPLICATIONS FOR HIV-ASSOCIATED NEUROCOGNITIVE DISORDER*S Received for publication,May 19, 2011, and in revised formAnatomyandNeurobiology,UniversityofPuertoRico,MedicalSciencesCampus,San Juan, Puerto Rico 00936-5067 Approximately 30­50% of the >30 million HIV-infected sub- jects develop

  10. Cisplatin upregulates mitochondrial nitric oxide synthase and peroxynitrite formation to promote renal injury

    SciTech Connect

    Jung, Michaela; Sola, Anna

    2009-01-15

    The mitochondria are a critical target for cisplatin-associated nephrotoxicity. Though nitric oxide formation has been implicated in the toxicity of cisplatin, this formation has not so far been related to a possible activation of mitochondrial nitric oxide synthase (mNOS). We show here that the upregulation of oxide mNOS and peroxynitrite formation in cisplatin treatment are key events that influence the development of the harmful parameters described in cisplatin-associated kidney failure. We confirm this by isolating the mitochondrial fraction of the kidney and across different access routes such as the use of a specific inhibitor of neuronal NOS, L-NPA, a peroxynitrite scavenger, FeTMPyP, and a peroxynitrite donor, SIN-1. The in vitro studies corroborated the information obtained in the in vivo experiments. The administration of cisplatin reveals a clear upregulation in the transcription of neuronal NOS and an increase in the levels of nitrites in the mitochondrial fractions of the kidneys. The upregulated transcription directly affects the cytoskeleton structure and the apoptosis. The inhibition of neuronal NOS reduces the levels of nitrites, cell death, and cytoskeleton derangement. Peroxynitrite is involved in the mechanism promoting the NOS transcription. In addition, in controls SIN-1 imitates the effects of cisplatin. In summary, we demonstrate that upregulation of mNOS in cisplatin treatment is a key component in both the initiation and the spread of cisplatin-associated damage in the kidney. Furthermore, peroxynitrite formation is directly involved in this process.

  11. Modulation of ultraviolet-induced hyperalgesia and cytokine upregulation by interleukins 10 and 13

    PubMed Central

    Saadé, Nayef E; Nasr, Isam W; Massaad, Cynthia A; Safieh-Garabedian, Bared; Jabbur, Suhayl J; Kanaan, Salim A

    2000-01-01

    Exposure to midrange ultraviolet radiation (UVB) is known to produce skin inflammation similar to sunburn. The aim of this study was to characterize the hyperalgesia and cytokine upregulation induced by UVB and their modulation by antiinflammatory cytokines. Acute exposure of the dorsal skin of mice to UVB (200, 250 and 300?mJ?cm2) resulted in a dose-dependent decrease in the latencies of the hot plate and tail flick tests, without evident signs of skin lesions. The observed hyperalgesia displayed a biphasic temporal evolution with an acute phase (3–6?h) and a late (48–96?h) phase. Exposure to UVB (300?mJ?cm2) elicited significant upregulation of interleukin (IL)-1?, tumour necrosis factor (TNF)-? and nerve growth factor (NGF), determined by ELISA in the exposed skin. This upregulation was more important during the acute phase of hyperalgesia. Daily treatment of mice, with i.p. injections of either IL-10 or IL-13 (1.5, 7.5 and 15?ng in 100??l saline) produced a dose-dependent attenuation of the UVB-induced hyperalgesia. Treatment with the highest doses of either IL-10 or IL-13, produced significant attenuation of the levels of the cytokines and NGF by UVB, with relatively more pronounced effects by IL-13. Acute exposure to moderate amounts of UVB results in a systemic hyperalgesia related to the upregulation of cytokine and NGF levels, since both were prevented by treatment with antiinflammatory cytokines. PMID:11090103

  12. Palladin is Upregulated in Kidney Disease and Contributes to Epithelial Cell Migration After Injury

    PubMed Central

    Chang, Emily H.; Gasim, Adil H.; Kerber, Michael L.; Patel, Julie B.; Glaubiger, Samuel A.; Falk, Ronald J.; Jennette, J. Charles; Otey, Carol A.

    2015-01-01

    Recovery from acute kidney injury involving tubular epithelial cells requires proliferation and migration of healthy cells to the area of injury. In this study, we show that palladin, a previously characterized cytoskeletal protein, is upregulated in injured tubules and suggest that one of its functions during repair is to facilitate migration of remaining cells to the affected site. In a mouse model of anti-neutrophilic cytoplasmic antibody involving both tubular and glomerular disease, palladin is upregulated in injured tubular cells, crescents and capillary cells with angiitis. In human biopsies of kidneys from patients with other kidney diseases, palladin is also upregulated in crescents and injured tubules. In LLC-PK1 cells, a porcine proximal tubule cell line, stress induced by transforming growth factor-?1 (TGF-?1) leads to palladin upregulation. Knockdown of palladin in LLC-PK1 does not disrupt cell morphology but does lead to a defect in cell migration. Furthermore, TGF-?1 induced increase in the 75?kDa palladin isoform occurs in both the nucleus and the cytoplasm. These data suggest that palladin expression is induced in injured cells and contributes to proper migration of cells in proximal tubules, possibly by regulation of gene expression as part of the healing process after acute injury. PMID:25573828

  13. Giant seaperch iridovirus infection upregulates Bas and Bak expression, leading to apoptotic death of fish cells.

    PubMed

    Chen, Xin-Yu; Wen, Chiu-Ming; Hui, Cho-Fat; Chen, Ming-Chyuan; Wu, Jen-Leih; Hsueh, Tsai-Ching; Lei, Wei-Han; Hong, Jiann-Ruey

    2015-08-01

    The giant seaperch iridovirus (GSIV) induces host cell apoptosis by a poorly-understood process. In this study, GSIV is shown to upregulate the pro-apoptotic death genes Bax and Bak at the middle replication stage, and factors in the grouper fin cell line (GF-1) are shown to modulate this process. Studying the mechanism of cell death, we found that upregulated, de novo-synthesized Bax and Bak proteins formed heterodimers. This up-regulation process correlated with mitochondrial membrane potential (MMP) loss, increased caspase-3 activity, and increased apoptotic cell death. All effects were diminished by treatment of infected GF-1 cells with the protein synthesis inhibitor cycloheximide. Interestingly, overexpression of the anti-apoptotic gene Bcl-xL also diminished GSIV-induced mitochondria-mediated cell death, increasing host cell viability and decreasing MMP loss at the early replication stage. Our data suggest that GSIV induces GF-1 apoptotic cell death through up-regulation of the pro-apoptotic genes Bax and Bak, which are regulated by Bcl-xL overexpression on mitochondria in GF-1 cells. PMID:26067170

  14. AGING UP-REGULATES EXPRESSION OF INFLAMMATORY MEDIATORS IN MOUSE ADIPOSE TISSUE (AT)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The incidence of type 2 diabetes (T2D) increases with age. Low-grade inflammation in AT is implicated in development of insulin resistance and T2D. This study investigated if inflammatory responses are up-regulated with age in AT. Results showed that visceral AT from old mice have higher mRNA expres...

  15. Male-Female Differences in Upregulation of Vasoconstrictor Responses in Human Cerebral Arteries

    PubMed Central

    Ahnstedt, Hilda; Cao, Lei; Krause, Diana N.; Warfvinge, Karin; Säveland, Hans; Nilsson, Ola G.; Edvinsson, Lars

    2013-01-01

    Background and purpose Male-female differences may significantly impact stroke prevention and treatment in men and women, however underlying mechanisms for sexual dimorphism in stroke are not understood. We previously found in males that cerebral ischemia upregulates contractile receptors in cerebral arteries, which is associated with lower blood flow. The present study investigates if cerebral arteries from men and women differ in cerebrovascular receptor upregulation. Experimental approach Freshly obtained human cerebral arteries were placed in organ culture, an established model for studying receptor upregulation. 5-hydroxtryptamine type 1B (5-HT1B), angiotensin II type 1 (AT1) and endothelin-1 type A and B (ETA and ETB) receptors were evaluated using wire myograph for contractile responses, real-time PCR for mRNA and immunohistochemistry for receptor expression. Key results Vascular sensitivity to angiotensin II and endothelin-1 was markedly lower in cultured cerebral arteries from women as compared to men. ETB receptor-mediated contraction occurred in male but not female arteries. Interestingly, there were similar upregulation in mRNA and expression of 5-HT1B, AT1, and ETB receptors and in local expression of Ang II after organ culture. Conclusions and Implications In spite of receptor upregulation after organ culture in both sexes, cerebral arteries from women were significantly less responsive to vasoconstrictors angiotensin II and endothelin-1 as compared to arteries from men. This suggests receptor coupling and/or signal transduction mechanisms involved in cerebrovascular contractility may be suppressed in females. This is the first study to demonstrate sex differences in the vascular function of human brain arteries. PMID:23658641

  16. Mechanism of Angiopoietin-1 Upregulation in Kaposi's Sarcoma-Associated Herpesvirus-Infected PEL Cell Lines

    PubMed Central

    Zheng, Xin; Ohsaki, Eriko

    2015-01-01

    ABSTRACT Angiopoietin-1 (ANGPT-1) is a secreted glycoprotein that was first characterized as a ligand of the Tie2 receptor. In a previous study using microarray analysis, we found that the expression of ANGPT-1 was upregulated in Kaposi's sarcoma-associated herpesvirus (KSHV)-infected primary effusion lymphoma (PEL) cell lines compared with that in uninfected Burkitt and other leukemia cell lines. Other authors have also reported focal expression of ANGPT-1 mRNA in biopsy specimens of Kaposi's sarcoma (KS) tissue from patients with AIDS. Here, to confirm these findings, we examined the expression and secretion levels of ANGPT-1 in KSHV-infected PEL cell lines and address the mechanisms of ANGPT-1 transcriptional regulation. We also showed that ANGPT-1 was expressed and localized in the cytoplasm and secreted into the supernatant of KSHV-infected PEL cells. Deletion studies of the regulatory region revealed that the region encompassing nucleotides ?143 to ?125 of the ANGPT-1-regulating sequence was responsible for this upregulation. Moreover, an electrophoretic mobility shift assay and chromatin immunoprecipitation, followed by quantitative PCR, suggested that some KSHV-infected PEL cell line-specific DNA-binding factors, such as OCT-1, should be involved in the upregulation of ANGPT-1 in a sequence-dependent manner. IMPORTANCE We confirmed that ANGPT-1 was expressed in and secreted from KSHV-infected PEL cells and that the transcriptional activity of ANGPT-1 was upregulated. A 19-bp fragment was identified as the region responsible for ANGPT-1 upregulation through binding with OCT-1 as a core factor in PEL cells. This study suggests that ANGPT-1 is overproduced in KSHV-infected PEL cells, which could affect the pathophysiology of AIDS patients with PEL. PMID:25631079

  17. Possible involvement of basic FGF in the upregulation of PDGFR? in pericytes after ischemic stroke.

    PubMed

    Nakamura, Kuniyuki; Arimura, Koichi; Nishimura, Ataru; Tachibana, Masaki; Yoshikawa, Yoji; Makihara, Noriko; Wakisaka, Yoshinobu; Kuroda, Junya; Kamouchi, Masahiro; Ooboshi, Hiroaki; Kitazono, Takanari; Ago, Tetsuro

    2016-01-01

    Central nervous system (CNS) pericytes have been recognized as an indispensable component of the neurovascular unit. The expression of platelet-derived growth factor receptor ? (PDGFR?) is markedly increased in CNS pericytes after brain ischemia. It has been elucidated that PDGFR?, expressed in pericytes and pericyte-derived fibroblast-like cells, plays important roles in the maintenance of the blood-brain barrier (BBB) and in the repair process in infarct areas. The aim of this study was to uncover how the PDGFR? expression is regulated in pericytes after brain ischemia. We found that basic fibroblast growth factor (bFGF), but neither hypoxia at 1% O2 nor acidification at pH 6.5, significantly upregulated the PDGFR? expression in human cultured CNS pericytes. SU5402, an inhibitor of FGF receptor (FGFR), and inhibitors of its downstream effectors Akt and Erk abolished the bFGF-induced upregulation of PDGFR?. On the other hand, acidification significantly upregulated the expression of bFGF, while hypoxia upregulated the expression of FGFR1 in the pericytes. The expression of bFGF and FGFR1 was markedly induced in the ischemic hemisphere after ischemic insult in a middle cerebral artery occlusion stroke model. Immunofluorescent double labeling demonstrated that the expression of bFGF and FGFR1 was co-localized with PDGFR?-positive cells in peri-infarct areas. Moreover, treatment with bFGF enhanced cell growth and the PDGF-BB-induced migratory activity of cultured pericytes, which were significantly suppressed by SU5402 or Sunitinib, an inhibitor of PDGFR. These data suggested that increased bFGF upregulates the expression of PDGFR? and may enhance PDGFR?-mediated pericyte functions after brain ischemia. PMID:26569132

  18. In Glaucoma the Upregulated Truncated TrkC.T1 Receptor Isoform in Glia Causes Increased TNF-

    E-print Network

    Burgess, Kevin

    In Glaucoma the Upregulated Truncated TrkC.T1 Receptor Isoform in Glia Causes Increased TNF and H. Uri Saragovi*,2,6,7 PURPOSE. Glaucoma is a distinct neuropathy characterized by the chronic-alpha (TNF- ). Previously, the authors showed that glaucoma causes a rapid upregulation of a neurotrophin

  19. Nicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend on Subunit Ratio*

    E-print Network

    Lasalde Dominicc, Jose A. - Department of Biology, Universidad de Puerto Rico

    acetylcholine receptors (nAChRs)1 belong to a superfamily of ligand-gated ion channels (e.g. -aminobu- tyricNicotine-induced Up-regulation and Desensitization of 4 2 Neuronal Nicotinic Receptors Depend exposure has been hypothesized to trigger the up-regulation of the 4 2 neuronal nicotinic acetylcholine

  20. Upregulation of early growth response factor-1 by bile acids requires mitogen-activated protein kinase signaling

    SciTech Connect

    Allen, Katryn; Kim, Nam Deuk; Moon, Jeon-OK; Copple, Bryan L.

    2010-02-15

    Cholestasis results when excretion of bile acids from the liver is interrupted. Liver injury occurs during cholestasis, and recent studies showed that inflammation is required for injury. Our previous studies demonstrated that early growth response factor-1 (Egr-1) is required for development of inflammation in liver during cholestasis, and that bile acids upregulate Egr-1 in hepatocytes. What remains unclear is the mechanism by which bile acids upregulate Egr-1. Bile acids modulate gene expression in hepatocytes by activating the farnesoid X receptor (FXR) and through activation of mitogen-activated protein kinase (MAPK) signaling. Accordingly, the hypothesis was tested that bile acids upregulate Egr-1 in hepatocytes by FXR and/or MAPK-dependent mechanisms. Deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) stimulated upregulation of Egr-1 to the same extent in hepatocytes isolated from wild-type mice and FXR knockout mice. Similarly, upregulation of Egr-1 in the livers of bile duct-ligated (BDL) wild-type and FXR knockout mice was not different. Upregulation of Egr-1 in hepatocytes by DCA and CDCA was prevented by the MEK inhibitors U0126 and SL-327. Furthermore, pretreatment of mice with U0126 prevented upregulation of Egr-1 in the liver after BDL. Results from these studies demonstrate that activation of MAPK signaling is required for upregulation of Egr-1 by bile acids in hepatocytes and for upregulation of Egr-1 in the liver during cholestasis. These studies suggest that inhibition of MAPK signaling may be a novel therapy to prevent upregulation of Egr-1 in liver during cholestasis.

  1. Upregulation of FOXM1 induces genomic instability in human epidermal keratinocytes

    PubMed Central

    2010-01-01

    Background The human cell cycle transcription factor FOXM1 is known to play a key role in regulating timely mitotic progression and accurate chromosomal segregation during cell division. Deregulation of FOXM1 has been linked to a majority of human cancers. We previously showed that FOXM1 was upregulated in basal cell carcinoma and recently reported that upregulation of FOXM1 precedes malignancy in a number of solid human cancer types including oral, oesophagus, lung, breast, kidney, bladder and uterus. This indicates that upregulation of FOXM1 may be an early molecular signal required for aberrant cell cycle and cancer initiation. Results The present study investigated the putative early mechanism of UVB and FOXM1 in skin cancer initiation. We have demonstrated that UVB dose-dependently increased FOXM1 protein levels through protein stabilisation and accumulation rather than de novo mRNA expression in human epidermal keratinocytes. FOXM1 upregulation in primary human keratinocytes triggered pro-apoptotic/DNA-damage checkpoint response genes such as p21, p38 MAPK, p53 and PARP, however, without causing significant cell cycle arrest or cell death. Using a high-resolution Affymetrix genome-wide single nucleotide polymorphism (SNP) mapping technique, we provided the evidence that FOXM1 upregulation in epidermal keratinocytes is sufficient to induce genomic instability, in the form of loss of heterozygosity (LOH) and copy number variations (CNV). FOXM1-induced genomic instability was significantly enhanced and accumulated with increasing cell passage and this instability was increased even further upon exposure to UVB resulting in whole chromosomal gain (7p21.3-7q36.3) and segmental LOH (6q25.1-6q25.3). Conclusion We hypothesise that prolonged and repeated UVB exposure selects for skin cells bearing stable FOXM1 protein causes aberrant cell cycle checkpoint thereby allowing ectopic cell cycle entry and subsequent genomic instability. The aberrant upregulation of FOXM1 serves as a 'first hit' where cells acquire genomic instability which in turn predisposes cells to a 'second hit' whereby DNA-damage checkpoint response (eg. p53 or p16) is abolished to allow damaged cells to proliferate and accumulate genetic aberrations/mutations required for cancer initiation. PMID:20187950

  2. Expression, purification, crystallization and preliminary X-ray analysis of the Met244Ala variant of catalase-peroxidase (KatG) from the haloarchaeon Haloarcula marismortui.

    PubMed

    Ten-I, Tomomi; Kumasaka, Takashi; Higuchi, Wataru; Tanaka, Satoru; Yoshimatsu, Katsuhiko; Fujiwara, Taketomo; Sato, Takao

    2007-11-01

    The covalent modification of the side chains of Trp95, Tyr218 and Met244 within the active site of Haloarcula marismortui catalase-peroxidase (KatG) appears to be common to all KatGs and has been demonstrated to be particularly significant for its bifunctionality [Smulevich et al. (2006), J. Inorg. Biochem. 100, 568-585; Jakopitsch, Kolarich et al. (2003), FEBS Lett. 552, 135-140; Jakopitsch, Auer et al. (2003), J. Biol. Chem. 278, 20185-20191; Jakopitsch et al. (2004), J. Biol. Chem. 279, 46082-46095; Regelsberger et al. (2001), Biochem. Soc. Trans. 29, 99-105; Ghiladi, Knudsen et al. (2005), J. Biol. Chem. 280, 22651-22663; Ghiladi, Medzihradzky et al. (2005), Biochemistry, 44, 15093-15105]. The Met244Ala variant of the H. marismortui KatG enzyme was expressed in haloarchaeal host cells and purified to homogeneity. The variant showed a complete loss of catalase activity, whereas the peroxidase activity of this mutant was highly enhanced owing to an increase in its affinity for the peroxidatic substrate. The variant was crystallized using the hanging-drop vapour-diffusion method with ammonium sulfate and NaCl as precipitants. The reddish-brown rod-shaped crystals obtained belong to the monoclinic space group C2, with unit-cell parameters a = 315.24, b = 81.04, c = 74.77 A, beta = 99.81 degrees . A crystal frozen using lithium sulfate as the cryoprotectant diffracted to beyond 2.0 A resolution. Preliminary X-ray analysis suggests the presence of a dimer in the asymmetric unit. PMID:18007045

  3. A Surface-Focused Biotinylation Procedure Identifies the Yersinia pestis Catalase KatY as a Membrane-Associated but Non-Surface-Located Protein?

    PubMed Central

    Myers-Morales, Tanya; Cowan, Clarissa; Gray, Michael E.; Wulff, Christine R.; Parker, Carol E.; Borchers, Christoph H.; Straley, Susan C.

    2007-01-01

    This study identified major surface proteins of the plague bacterium Yersinia pestis. We applied a novel surface biotinylation method, followed by NeutrAvidin (NA) bead capture, on-bead digestion, and identification by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The use of stachyose during biotinylation focused the reaction to the surface. Coupled with NA pulldown and immunoblot analysis, this method determined whether a protein was accessible to the surface. We applied the method to test the hypothesis that the catalase KatY is a surface protein of the plague bacterium Y. pestis. A rabbit serum recognized the catalase KatY as a major putative outer membrane-associated antigen expressed by Y. pestis cells grown at 37°C. Similar findings by other groups had led to speculations that this protein might be exposed to the surface and might be a candidate for evaluation as a protective antigen for an improved plague vaccine. KatY was obtained only in the total membrane fraction, and stachyose greatly reduced its biotinylation as well as that of the periplasmic maltose binding protein, indicating that KatY is not on the bacterial surface. LC-MS-MS analysis of on-bead digests representing ca. 109 cells identified highly abundant species, including KatY, Pal, and OmpA, as well as the lipoprotein Pcp, all of which bound in a biotin-specific manner. Pla, Lpp, and OmpX (Ail) bound to the NA beads in a non-biotin-specific manner. There was no contamination from abundant cytoplasmic proteins. We hypothesize that OmpX and Pcp are highly abundant and likely to be important for the Y. pestis pathogenic process. We speculate that a portion of KatY associates with the outer membrane in intact cells but that it is located on the periplasmic side. Consistent with this idea, it did not protect C57BL/6 mice against bubonic plague. PMID:17644638

  4. Effect of Yerbimat herbicide on lipid peroxidation, catalase activity, and histological damage in gills and liver of the freshwater fish Goodea atripinnis.

    PubMed

    Ortiz-Ordoñez, Esperanza; Uría-Galicia, Esther; Ruiz-Picos, Ricardo Arturo; Duran, Angela Georgina Sánchez; Trejo, Yoseline Hernández; Sedeño-Díaz, Jacinto Elías; López-López, Eugenia

    2011-10-01

    The use of herbicides for agricultural and aquatic weed control has increased worldwide. These substances are potentially toxic pollutants because they induce the production of reactive oxygen species for biological systems and exert oxidative stress in nontarget organisms living in the treated aquatic systems. Recent evidence suggests differences in the toxicity of glyphosate in the form of an active ingredient compared to the toxicity of glyphosate in combination with surfactants, such as those found in commercial formulations. In Mexico, one of the most widely used glyphosate-based herbicides is Yerbimat, which has agricultural as well as aquatic weed control applications. However, there are no aquatic toxicity data, particularly regarding native fish. Therefore, we determined the acute toxicity of commercial-formulation Yerbimat in a static bioassay at 96 h (LC(50)). We also determined its toxicity at 96 h in sublethal concentrations to assess the lipid peroxidation levels (LPX), catalase activity, hepatic glycogen content, and histological damage in the liver and gills of the fish Goodea atripinnis associated with chronic exposure (75 days). The LC(50) was 38.95 ± 0.33 mg/L. The results of the short-term exposure study indicate that Yerbimat can potentially induce oxidative stress in G. atripinnis, because LPX was increased in the gills and liver. Catalase activity was reduced in the gills but increased in the liver, whereas hepatic glycogen was depleted. Chronic exposure was associated with histopathological damage in the gills and liver, some of which was irreversible. Yerbimat represents a potential risk for aquatic biota; therefore, we recommend that its application be carefully considered. PMID:21305274

  5. Auxins Upregulate Expression of the Indole-3-Pyruvate Decarboxylase Gene in Azospirillum brasilense

    PubMed Central

    Vande Broek, Ann; Lambrecht, Mark; Eggermont, Kristel; Vanderleyden, Jos

    1999-01-01

    Transcription of the Azospirillum brasilense ipdC gene, encoding an indole-3-pyruvate decarboxylase involved in the biosynthesis of indole-3-acetic acid (IAA), is induced by IAA as determined by ipdC-gusA expression studies and Northern analysis. Besides IAA, exogenously added synthetic auxins such as 1-naphthaleneacetic acid, 2,4-dichlorophenoxypropionic acid, and p-chlorophenoxyacetic acid were also found to upregulate ipdC expression. No upregulation was observed with tryptophan, acetic acid, or propionic acid or with the IAA conjugates IAA ethyl ester and IAA-l-phenylalanine, indicating structural specificity is required for ipdC induction. This is the first report describing the induction of a bacterial gene by auxin. PMID:9973364

  6. Up-regulation of cyclooxygenase-2 by product-prostaglandin E2

    NASA Technical Reports Server (NTRS)

    Tjandrawinata, R. R.; Hughes-Fulford, M.

    1997-01-01

    The development of prostate cancer has been linked to high level of dietary fat intake. Our laboratory investigates the connection between cancer cell growth and fatty acid products. Studying human prostatic carcinoma PC-3 cells, we found that prostaglandin E2 (PGE2) increased cell growth and up-regulated the gene expression of its own synthesizing enzyme, cyclooxygenase-2 (COX-2). PGE2 increased COX-2 mRNA expression dose-dependently with the highest levels of stimulation seen at the 3-hour period following PGE2 addition. The NSAID flurbiprofen (5 microM), in the presence of exogenous PGE2, inhibited the up-regulation of COX-2 mRNA and cell growth. These data suggest that the levels of local intracellular PGE2 play a major role in the growth of prostate cancer cells through an activation of COX-2 gene expression.

  7. Upregulation of microRNA processing enzymes Drosha and Dicer in gestational diabetes mellitus.

    PubMed

    Rahimi, Giti; Jafari, Naser; Khodabakhsh, Mehnoush; Shirzad, Zohreh; Dogaheh, Hadi Peeri

    2015-02-01

    MicroRNAs (miRNAs) have been shown to play important roles in diverse cellular processes and linked to variety of disorders. Dicer and Drosha are two major enzymes in the miRNA biogenesis process. DGCR8 is the assistant of Drosha in the microprocessor complex. In this study, we evaluated the mRNA expression profiles of major miRNA processing machinery Drosha, Dicer, and DGCR8 in gestational diabetes mellitus (GDM), pregnant and healthy women. Our findings indicate that the expression levels of Drosha, Dicer and DGCR8 were upregulated in both pregnant and GDM patients compared to the control group. However, Drosha and Dicer were upregulated more than pregnant group. In conclusion, we detected dysregulation of Drosha, Dicer and DGCR8 expression in pregnant and GDM patients when compared to healthy control participants. Therefore, we favor the hypothesis that miRNAs are involved in the development of GDM. PMID:25295740

  8. Wnt/?-catenin up-regulates Midkine expression in glioma cells

    PubMed Central

    Tang, Shi-Lei; Gao, Yuan-Lin; Chen, Xiao-Bing

    2015-01-01

    Midkine, also known as neurite growth-promoting factor 2 (NEGF2), plays an important role in cell proliferation, apoptosis and differentiation. Recent studies have shown that Midkine is up-regulated in several types of human cancers. However, the molecular mechanism for its up-regulation remains poorly understood. Activation of Wnt/?-catenin signaling is viewed as crucial for multiple tumor growth and metastasis, including glioma. In the present study, we found that Wnt3a administration or transfection of a constitutively activated ?-catenin promoted Midkine expression in glioma cells. We further identified a TCF/LEF binding site, with which beta-catenin interacts, on the proximal promoter region of Midkine gene, by luciferase reporter and chromatin immunoprecipitation assays. Thus, our results suggest a previously unknown Wnt/?-catenin/Midkine molecular network controlling glioma development. PMID:26550177

  9. Deferoxamine Attenuated the Upregulation of Lipocalin-2 Induced by Traumatic Brain Injury in Rats.

    PubMed

    Zhao, Jinbing; Xi, Guohua; Wu, Gang; Keep, Richard F; Hua, Ya

    2016-01-01

    Intracranial hemorrhage is one of the most common consequences of traumatic brain injury (TBI). The release of iron from the breakdown of hemoglobin during intracerebral hematoma resolution results in an increase in perihematomal non-heme iron. Lipocalin 2 (LCN-2) is a siderophore-binding protein that mediates transferrin-independent iron transport. This study examined the effects of TBI (lateral fluid percussion) on LCN-2 expression in Sprague-Dawley rats. LCN-2 protein levels were markedly increased in the ipsilateral cortex and hippocampus after TBI, with the highest level at day 1. Most LCN-2-positive cells appeared to be astrocytes. Treatment with an iron chelator, deferoxamine (100 mg/kg, intramuscularly), attenuated the TBI-induced upregulation of LCN-2. In summary, TBI resulted in upregulation of LCN-2 and deferoxamine reduced TBI-induced LCN-2 increase, suggesting LCN-2 may have a role in iron-trafficking after TBI. PMID:26463963

  10. Nicotine-induced Upregulation of Nicotinic Receptors: Underlying Mechanisms and Relevance to Nicotine Addiction

    PubMed Central

    Govind, Anitha P.; Vezina, Paul; Green, William N.

    2009-01-01

    A major hurdle in defining the molecular biology of nicotine addiction has been characterizing the different nicotinic acetylcholine receptor (nAChR) subtypes in the brain and how nicotine alters their function. Mounting evidence suggests that the addictive effects of nicotine, like other drugs of abuse, occur through interactions with its receptors in the mesolimbic dopamine system, particularly ventral tegmental area (VTA) neurons, where nicotinic receptors act to modulate the release of dopamine. The molecular identity of the nicotinic receptors responsible for drug seeking behavior, their cellular and subcellular location and the mechanisms by which these receptors initiate and maintain addiction are poorly defined. In this commentary, we review how nicotinic acetylcholine receptors (nAChRs) are upregulated by nicotine exposure, the potential posttranslational events that appear to cause it and how upregulation is linked to nicotine addiction. PMID:19540212

  11. Human cytomegalovirus inhibits apoptosis involving upregulation of the antiapoptotic protein Bag-1.

    PubMed

    Li, Hai Ping; Yuan, Cong Ling; Zho, Ying Chun

    2015-11-01

    Human cytomegalovirus (HCMV) is an important opportunistic pathogen in immunocompromised individuals and is recognized as a major viral cause of birth defects. HCMV has the ability to establish lifelong persistence and latent infection following primary exposure. Apoptosis is an innate cellular defense response to viral infection. HCMV can block apoptosis in various cell types. Here we show that HCMV promotes survival of human embryonic lung fibroblasts by activating of MAPK/ERK signaling pathway. Bag-1 is up-regulated in a MAPK/ERK-dependent fashion in infected cells. Depletion of Bag-1 suppresses the antiapoptotic effect of HCMV. Taken together, these data indicate that Bag-1 up-regulation is required to maintain apoptosis resistance in HCMV infected cells. PMID:26087710

  12. Airway epithelial platelet-activating factor receptor expression is markedly upregulated in chronic obstructive pulmonary disease

    PubMed Central

    Shukla, Shakti Dhar; Sohal, Sukhwinder Singh; Mahmood, Malik Quasir; Reid, David; Muller, Hans Konrad; Walters, Eugene Haydn

    2014-01-01

    Background We recently published that platelet-activating factor receptor (PAFr) is upregulated on the epithelium of the proximal airways of current smokers and also in bronchial epithelial cells exposed to cigarette smoke extract. These treated cells also showed upregulation of Streptococcus pneumoniae adhesion. Bacterial wall phosphorylcholine specifically binds to PAFr expressed on airway epithelium, thus facilitating adherence and tissue invasion, which may be relevant to chronic obstructive pulmonary disease (COPD). Moreover, the use of inhaled corticosteroids (ICS) in COPD patients is associated with an increased risk of invasive respiratory pneumococcal infections. Objective In this study, we have investigated whether PAFr expression is especially upregulated in airway epithelium in COPD patients and whether this expression may be modulated by ICS therapy. Methods We cross-sectionally evaluated PAFr expression in bronchial biopsies from 15 COPD patients who were current smokers (COPD-smokers) and 12 COPD-ex-smokers, and we compared these to biopsies from 16 smokers with normal lung function. We assessed immunostaining with anti-PAFr monoclonal antibody. We also used material from a previous double-blinded randomized placebo-controlled 6-month ICS intervention study in COPD patients to explore the effect of ICS on PAFr expression. We employed computer-aided image analysis to quantify the percentage of epithelium stained for PAFr. Results Markedly enhanced expression of PAFr was found in both COPD-smokers (P<0.005) and COPD-ex-smokers (P<0.002) compared to smokers with normal lung function. There was little evidence that PAFr expression was affected by ICS therapy over 6 months. Conclusion Epithelial PAFr expression is upregulated in smokers, especially in those with COPD, and is not obviously affected by ICS therapy. PMID:25143722

  13. Functional Upregulation of ?4* Nicotinic Acetylcholine Receptors in VTA GABAergic Neurons Increases Sensitivity to Nicotine Reward

    PubMed Central

    Ngolab, Jennifer; Liu, Liwang; Zhao-Shea, Rubing; Gao, Guangping; Gardner, Paul D.

    2015-01-01

    Chronic nicotine exposure increases sensitivity to nicotine reward during a withdrawal period, which may facilitate relapse in abstinent smokers, yet the molecular neuroadaptation(s) that contribute to this phenomenon are unknown. Interestingly, chronic nicotine use induces functional upregulation of nicotinic acetylcholine receptors (nAChRs) in the mesocorticolimbic reward pathway potentially linking upregulation to increased drug sensitivity. In the ventral tegmental area (VTA), functional upregulation of nAChRs containing the ?4 subunit (?4* nAChRs) is restricted to GABAergic neurons. To test the hypothesis that increased functional expression of ?4* nAChRs in these neurons modulates nicotine reward behaviors, we engineered a Cre recombinase-dependent gene expression system to selectively express ?4 nAChR subunits harboring a “gain-of-function” mutation [a leucine mutated to a serine residue at the 9? position (Leu9?Ser)] in VTA GABAergic neurons of adult mice. In mice expressing Leu9?Ser ?4 nAChR subunits in VTA GABAergic neurons (Gad2VTA:Leu9?Ser mice), subreward threshold doses of nicotine were sufficient to selectively activate VTA GABAergic neurons and elicit acute hypolocomotion, with subsequent nicotine exposures eliciting tolerance to this effect, compared to control animals. In the conditioned place preference procedure, nicotine was sufficient to condition a significant place preference in Gad2VTA:Leu9?Ser mice at low nicotine doses that failed to condition control animals. Together, these data indicate that functional upregulation of ?4* nAChRs in VTA GABAergic neurons confers increased sensitivity to nicotine reward and points to nAChR subtypes specifically expressed in GABAergic VTA neurons as molecular targets for smoking cessation therapeutics. PMID:26041923

  14. HDAC Inhibition Upregulates PD-1 Ligands in Melanoma and Augments Immunotherapy with PD-1 Blockade.

    PubMed

    Woods, David M; Sodré, Andressa L; Villagra, Alejandro; Sarnaik, Amod; Sotomayor, Eduardo M; Weber, Jeffrey

    2015-12-01

    Expression of PD-1 ligands by tumors and interaction with PD-1-expressing T cells in the tumor microenvironment can result in tolerance. Therapies targeting this coinhibitory axis have proven clinically successful in the treatment of metastatic melanoma, non-small cell lung cancer, and other malignancies. Therapeutic agents targeting the epigenetic regulatory family of histone deacetylases (HDAC) have shown clinical success in the treatment of some hematologic malignancies. Beyond direct tumor cell cytotoxicity, HDAC inhibitors have also been shown to alter the immunogenicity and enhance antitumor immune responses. Here, we show that class I HDAC inhibitors upregulated the expression of PD-L1 and, to a lesser degree, PD-L2 in melanomas. Evaluation of human and murine cell lines and patient tumors treated with a variety of HDAC inhibitors in vitro displayed upregulation of these ligands. This upregulation was robust and durable, with enhanced expression lasting past 96 hours. These results were validated in vivo in a B16F10 syngeneic murine model. Mechanistically, HDAC inhibitor treatment resulted in rapid upregulation of histone acetylation of the PD-L1 gene leading to enhanced and durable gene expression. The efficacy of combining HDAC inhibition with PD-1 blockade for treatment of melanoma was also explored in a murine B16F10 model. Mice receiving combination therapy had a slower tumor progression and increased survival compared with control and single-agent treatments. These results highlight the ability of epigenetic modifiers to augment immunotherapies, providing a rationale for combining HDAC inhibitors with PD-1 blockade. Cancer Immunol Res; 3(12); 1375-85. ©2015 AACR. PMID:26297712

  15. Rapid systemic up-regulation of genes after heat-wounding and electrical stimulation

    NASA Technical Reports Server (NTRS)

    Davies, E.; Vian, A.; Vian, C.; Stankovic, B.

    1997-01-01

    When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.

  16. Gene up-regulation in response to predator kairomones in the water flea, Daphnia pulex

    PubMed Central

    2010-01-01

    Background Numerous cases of predator-induced polyphenisms, in which alternate phenotypes are produced in response to extrinsic stimuli, have been reported in aquatic taxa to date. The genus Daphnia (Branchiopoda, Cladocera) provides a model experimental system for the study of the developmental mechanisms and evolutionary processes associated with predator-induced polyphenisms. In D. pulex, juveniles form neckteeth in response to predatory kairomones released by Chaoborus larvae (Insecta, Diptera). Results Previous studies suggest that the timing of the sensitivity to kairomones in D. pulex can generally be divided into the embryonic and postembryonic developmental periods. We therefore examined which of the genes in the embryonic and first-instar juvenile stages exhibit different expression levels in the presence or absence of predator kairomones. Employing a candidate gene approach and identifying differentially-expressed genes revealed that the morphogenetic factors, Hox3, extradenticle and escargot, were up-regulated by kairomones in the postembryonic stage and may potentially be responsible for defense morph formation. In addition, the juvenile hormone pathway genes, JHAMT and Met, and the insulin signaling pathway genes, InR and IRS-1, were up-regulated in the first-instar stage. It is well known that these hormonal pathways are involved in physiological regulation following morphogenesis in many insect species. During the embryonic stage when morphotypes were determined, one of the novel genes identified by differential display was up-regulated, suggesting that this gene may be related to morphotype determination. Biological functions of the up-regulated genes are discussed in the context of defense morph formation. Conclusions It is suggested that, following the reception of kairomone signals, the identified genes are involved in a series of defensive phenotypic alterations and the production of a defensive phenotype. PMID:20433737

  17. Upregulation of articular synovial membrane ?-opioid-like receptors in an acute equine synovitis model.

    PubMed

    van Loon, J P A M; de Grauw, J C; Brunott, A; Weerts, E A W S; van Weeren, P R

    2013-04-01

    Intra-articular injection of opioids provides analgesia in painful equine joints and ?-opioid receptors (MORs) have been demonstrated in equine synovial membranes. The aim of this study was to determine whether acute inflammatory conditions will lead to up-regulation of MOR in equine synovial membranes and whether anti-inflammatory treatment can prevent any such upregulation. In a two-period, blinded, placebo-controlled randomised cross-over design, lipopolysaccharide (LPS, 1.0 ng) was injected into the left or right middle carpal joint of seven healthy ponies. Arthroscopy and synovial membrane biopsy was performed under general anaesthesia at baseline, 48 h (T48) and 672 h (T672) after LPS injection, with ponies assigned to receive either phenylbutazone (PBZ 2.2mg/kg PO BID) or placebo from 2h post-LPS. Ponies were scored for pain and lameness. Repeated synovial fluid samples were obtained and the degree of synovitis scored both macroscopically and microscopically. The density and staining pattern of MOR-like protein in synovial membrane biopsies over the course of the synovitis with or without PBZ treatment was evaluated using immunohistochemical techniques. LPS injection consistently induced a severe transient synovitis. Pain and lameness were significantly attenuated by treatment with PBZ. Up-regulation of MOR-like protein in the inflamed equine synovial membrane could be demonstrated in the placebo treated animals, but not in the PBZ-treated animals overall, although there were no significant differences at any individual time-point between the two groups. It was concluded that acute inflammation will up-regulate MOR, while anti-inflammatory treatment will attenuate this response. PMID:22939088

  18. High Glucose Up-regulates ADAM17 through HIF-1? in Mesangial Cells.

    PubMed

    Li, Renzhong; Uttarwar, Lalita; Gao, Bo; Charbonneau, Martine; Shi, Yixuan; Chan, John S D; Dubois, Claire M; Krepinsky, Joan C

    2015-08-28

    We previously showed that ADAM17 mediates high glucose-induced matrix production by kidney mesangial cells. ADAM17 expression is increased in diabetic kidneys, suggesting that its up-regulation may augment high glucose profibrotic responses. We thus studied the effects of high glucose on ADAM17 gene regulation. Primary rat mesangial cells were treated with high glucose (30 mm) or mannitol as osmotic control. High glucose dose-dependently increased ADAM17 promoter activity, transcript, and protein levels. This correlated with augmented ADAM17 activity after 24 h versus 1 h of high glucose. We tested involvement of transcription factors shown in other settings to regulate ADAM17 transcription. Promoter activation was not affected by NF-?B or Sp1 inhibitors, but was blocked by hypoxia-inducible factor-1? (HIF-1?) inhibition or down-regulation. This also prevented ADAM17 transcript and protein increases. HIF-1? activation by high glucose was shown by its increased nuclear translocation and activation of the HIF-responsive hypoxia-response element (HRE)-luciferase reporter construct. Assessment of ADAM17 promoter deletion constructs coupled with mutation analysis and ChIP studies identified HIF-1? binding to its consensus element at -607 as critical for the high glucose response. Finally, inhibitors of epidermal growth factor receptor (EGFR) and downstream PI3K/Akt, or ADAM17 itself, prevented high glucose-induced HIF-1? activation and ADAM17 up-regulation. Thus, high glucose induces ADAM17 transcriptional up-regulation in mesangial cells, which is associated with augmentation of its activity. This is mediated by HIF-1? and requires EGFR/ADAM17 signaling, demonstrating the potentiation by ADAM17 of its own up-regulation. ADAM17 inhibition thus provides a potential novel therapeutic strategy for the treatment of diabetic nephropathy. PMID:26175156

  19. Eurycomanone induce apoptosis in HepG2 cells via up-regulation of p53

    PubMed Central

    Zakaria, Yusmazura; Rahmat, Asmah; Pihie, Azimahtol Hawariah Lope; Abdullah, Noor Rain; Houghton, Peter J

    2009-01-01

    Background Eurycomanone is a cytotoxic compound found in Eurycoma longifolia Jack. Previous studies had noted the cytotoxic effect against various cancer cell lines. The aim of this study is to investigate the cytotoxicity against human hepato carcinoma cell in vitro and the mode of action. The cytotoxicity of eurycomanone was evaluated using MTT assay and the mode of cell death was detected by Hoechst 33258 nuclear staining and flow cytometry with Annexin-V/propidium iodide double staining. The protein expression Bax, Bcl-2, p53 and cytochrome C were studied by flow cytometry using a spesific antibody conjugated fluorescent dye to confirm the up-regulation of p53 and Bax in cancer cells. Results The findings suggested that eurycomanone was cytotoxic on cancerous liver cell, HepG2 and less toxic on normal cells Chang's liver and WLR-68. Furthermore, various methods proved that apoptosis was the mode of death in eurycomanone-treated HepG2 cells. The characteristics of apoptosis including chromatin condensation, DNA fragmentation and apoptotic bodies were found following eurycomanone treatment. This study also found that apoptotic process triggered by eurycomanone involved the up-regulation of p53 tumor suppressor protein. The up-regulation of p53 was followed by the increasing of pro-apoptotic Bax and decreasing of anti-apoptotic Bcl-2. The increased of cytochrome C levels in cytosol also results in induction of apoptosis. Conclusion The data suggest that eurycomanone was cytotoxic on HepG2 cells by inducing apoptosis through the up-regulation of p53 and Bax, and down-regulation of Bcl-2. PMID:19508737

  20. Acid Ceramidase Upregulation in Prostate Cancer Cells Confers Resistance to Radiation: AC Inhibition, a Potential Radiosensitizer

    PubMed Central

    Mahdy, Ayman EM; Cheng, Joseph C; Li, Jun; Elojeimy, Saeed; Meacham, William D; Turner, Lorianne S; Bai, Aiping; Gault, Christopher R; McPherson, Alex S; Garcia, Nicole; Beckham, Thomas H; Saad, Antonio; Bielawska, Alicja; Bielawski, Jacek; Hannun, Yusuf A; Keane, Thomas E; Taha, Mohhammed I; Hammouda, Hisham M; Norris, James S; Liu, Xiang

    2008-01-01

    Radiation resistance in a subset of prostate tumors remains a challenge to prostate cancer radiotherapy. The current study on the effects of radiation on prostate cancer cells reveals that radiation programs an unpredicted resistance mechanism by upregulating acid ceramidase (AC). Irradiated cells demonstrated limited changes of ceramide levels while elevating levels of sphingosine and sphingosine-1-phosphate. By genetically downregulating AC with small interfering RNA (siRNA), we observed radiosensitization of cells using clonogenic and cytotoxicity assays. Conversely, AC overexpression further decreased sensitivity to radiation. We also observed that radiation-induced AC upregulation was sufficient to create cross-resistance to chemotherapy as demonstrated by decreased sensitivity to Taxol and C6 ceramide compared to controls. Lower levels of caspase 3/7 activity were detected in cells pretreated with radiation, also indicating increased resistance. Finally, utilization of the small molecule AC inhibitor, LCL385, sensitized PPC-1 cells to radiation and significantly decreased tumor xenograft growth. These data suggest a new mechanism of cancer cell resistance to radiation, through upregulation of AC that is, in part, mediated by application of the therapy itself. An improved understanding of radiotherapy and the application of combination therapy achieved in this study offer new opportunities for the modulation of radiation effects in the treatment of cancer. PMID:19107118

  1. Regional upregulation of hippocampal melatonin MT2 receptors by valproic acid: therapeutic implications for Alzheimer's disease.

    PubMed

    Bahna, Sarra G; Sathiyapalan, Arani; Foster, Jane A; Niles, Lennard P

    2014-07-25

    We have reported that clinically relevant concentrations of valproic acid (VPA) upregulate the G protein-coupled melatonin MT1 receptor in rat C6 glioma cells, and both MT1 and MT2 receptors in the rat hippocampus. The melatonin MT2 receptor is relatively enriched in the hippocampus, where it is thought to be involved in modulating synaptic plasticity and cognitive function. Importantly, a significant decrease in MT2 expression has been observed in the hippocampus of Alzheimer's patients. Therefore, we examined whether the global upregulation of this receptor (and also the MT1) by VPA, observed in earlier RT-PCR and real time PCR studies, could be localized to more discrete hippocampal regions, which are involved in cognitive function. In situ hybridization of rat brain slices, following chronic VPA treatment (3mg/mL or 4mg/mL in drinking water), revealed a significant upregulation of the MT2 receptor mRNA in the CA1, CA2, CA3 and dentate gyrus (DG) regions of the rat hippocampus. In contrast, the MT1 receptor was not detected in the hippocampus by in situ hybridization. The significant induction of melatonin MT2 receptor expression by VPA in hippocampal regions involved in learning, memory and/or neural stem cell proliferation, suggests that a combinatorial therapeutic strategy involving VPA together with melatonin or other MT2 agonists, would be beneficial in neurodegenerative disorders such as Alzheimer's disease. PMID:24909617

  2. Chemokine up-regulation in SARS-coronavirus-infected, monocyte-derived human dendritic cells.

    PubMed

    Law, Helen K W; Cheung, Chung Yan; Ng, Hoi Yee; Sia, Sin Fun; Chan, Yuk On; Luk, Winsie; Nicholls, John M; Peiris, J S Malik; Lau, Yu Lung

    2005-10-01

    Lymphopenia and increasing viral load in the first 10 days of severe acute respiratory syndrome (SARS) suggested immune evasion by SARS-coronavirus (CoV). In this study, we focused on dendritic cells (DCs) which play important roles in linking the innate and adaptive immunity. SARS-CoV was shown to infect both immature and mature human monocyte-derived DCs by electron microscopy and immunofluorescence. The detection of negative strands of SARS-CoV RNA in DCs suggested viral replication. However, no increase in viral RNA was observed. Using cytopathic assays, no increase in virus titer was detected in infected DCs and cell-culture supernatant, confirming that virus replication was incomplete. No induction of apoptosis or maturation was detected in SARS-CoV-infected DCs. The SARS-CoV-infected DCs showed low expression of antiviral cytokines (interferon alpha [IFN-alpha], IFN-beta, IFN-gamma, and interleukin 12p40 [IL-12p40]), moderate up-regulation of proinflammatory cytokines (tumor necrosis factor alpha [TNF-alpha] and IL-6) but significant up-regulation of inflammatory chemokines (macrophage inflammatory protein 1alpha [MIP-1alpha], regulated on activation normal T cell expressed and secreted [RANTES]), interferon-inducible protein of 10 kDa [IP-10], and monocyte chemoattractant protein 1 [MCP-1]). The lack of antiviral cytokine response against a background of intense chemokine up-regulation could represent a mechanism of immune evasion by SARS-CoV. PMID:15860669

  3. Hypoxia promotes colon cancer dissemination through up-regulation of cell migration-inducing protein (CEMIP)

    PubMed Central

    Kuscu, Cem; Liu, Jingxuan; Cathcart, Jillian; Banach, Anna; Zhang, Qian; Li, Ellen; Joshi, Sonia; Yang, Jie; Denoya, Paula I; Pastorekova, Silvia; Zucker, Stanley; Shroyer, Kenneth R.; Cao, Jian

    2015-01-01

    Hypoxic stress drives cancer progression by causing a transcriptional reprogramming. Recently, KIAA1199 was discovered to be a cell-migration inducing protein (renamed CEMIP) that is upregulated in human cancers. However, the mechanism of induction of CEMIP in cancer was hitherto unknown. Here we demonstrate that hypoxia induces CEMIP expression leading to enhanced cell migration. Immunohistochemistry of human colon cancer tissues revealed that CEMIP is upregulated in cancer cells located at the invasive front or in the submucosa. CEMIP localization inversely correlated with E-cadherin expression, which is characteristic of the epithelial-to-mesenchymal transition. Mechanistically, hypoxia-inducible-factor-2? (HIF-2?), but not HIF-1? binds directly to the hypoxia response element within the CEMIP promoter region resulting in increased CEMIP expression. Functional characterization reveals that CEMIP is a downstream effector of HIF-2?-mediated cell migration. Expression of CEMIP was demonstrated to negatively correlate with the expression of Jarid1A, a histone demethylase that removes methyl groups from H3K4me3 (an activation marker for transcription), resulting in altered gene repression. Low oxygen tension inhibits the function of Jarid1A, leading to increased presence of H3K4me3 within the CEMIP promoter. These results provide insight into the upregulation of CEMIP within cancer and can lead to novel treatment strategies targeting this cancer cell migration-promoting gene. PMID:26009875

  4. Herp depletion protects from protein aggregation by up-regulating autophagy.

    PubMed

    Quiroga, Clara; Gatica, Damian; Paredes, Felipe; Bravo, Roberto; Troncoso, Rodrigo; Pedrozo, Zully; Rodriguez, Andrea E; Toro, Barbra; Chiong, Mario; Vicencio, Jose Miguel; Hetz, Claudio; Lavandero, Sergio

    2013-12-01

    Herp is an endoplasmic reticulum (ER) stress inducible protein that participates in the ER-associated protein degradation (ERAD) pathway. However, the contribution of Herp to other protein degradation pathways like autophagy and its connection to other types of stress responses remain unknown. Here we report that Herp regulates autophagy to clear poly-ubiquitin (poly-Ub) protein aggregates. Proteasome inhibition and glucose starvation (GS) led to a high level of poly-Ub protein aggregation that was drastically reduced by stably knocking down Herp (shHerp cells). The enhanced removal of poly-Ub inclusions protected cells from death caused by glucose starvation. Under basal conditions and increasingly after stress, higher LC3-II levels and GFP-LC3 puncta were observed in shHerp cells compared to control cells. Herp knockout cells displayed basal up-regulation of two essential autophagy regulators-Atg5 and Beclin-1, leading to increased autophagic flux. Beclin-1 up-regulation was due to a reduction in Hrd1 dependent proteasomal degradation, and not at transcriptional level. The consequent higher autophagic flux was necessary for the clearance of aggregates and for cell survival. We conclude that Herp operates as a relevant factor in the defense against glucose starvation by modulating autophagy levels. These data may have important implications due to the known up-regulation of Herp in pathological states such as brain and heart ischemia, both conditions associated to acute nutritional stress. PMID:24120520

  5. Low-level laser therapy promotes dendrite growth via upregulating brain-derived neurotrophic factor expression

    NASA Astrophysics Data System (ADS)

    Meng, Chengbo; He, Zhiyong; Xing, Da

    2014-09-01

    Downregulation of brain-derived neurotrophic factor (BDNF) in the hippocampus occurs early in the progression of Alzheimer's disease (AD). Since BDNF plays a critical role in neuronal survival and dendrite growth, BDNF upregulation may contribute to rescue dendrite atrophy and cell loss in AD. Low-level laser therapy (LLLT) has been demonstrated to regulate neuronal function both in vitro and in vivo. In the present study, we found that LLLT rescued neurons loss and dendritic atrophy via the increase of both BDNF mRNA and protein expression. In addition, dendrite growth was improved after LLLT, characterized by upregulation of PSD95 expression, and the increase in length, branching, and spine density of dendrites in hippocampal neurons. Together, these studies suggest that upregulation of BDNF with LLLT can ameliorate A?-induced neurons loss and dendritic atrophy, thus identifying a novel pathway by which LLLT protects against A?-induced neurotoxicity. Our research may provide a feasible therapeutic approach to control the progression of Alzheimer's disease.

  6. Placental fractalkine is up-regulated in severe early-onset preeclampsia.

    PubMed

    Siwetz, Monika; Dieber-Rotheneder, Martina; Cervar-Zivkovic, Mila; Kummer, Daniel; Kremshofer, Julia; Weiss, Gregor; Herse, Florian; Huppertz, Berthold; Gauster, Martin

    2015-05-01

    The pathogenesis of preeclampsia (PE) includes the release of placental factors into the maternal circulation, inducing an inflammatory environment in the mother. One of the factors may be the proinflammatory chemokine fractalkine, which is expressed in the syncytiotrophoblast of human placenta, from where it is released into the maternal circulation by constitutive shedding. We examined whether placental fractalkine is up-regulated in severe early-onset PE and whether the proinflammatory cytokines tumor necrosis factor (TNF)-? and IL-6 are able to increase the expression of fractalkine. Gene expression analysis, enzyme-linked immunosorbent assay, and immunohistochemistry consistently showed increased fractalkine expression in placentas from severe early-onset PE, compared to gestational age-matched controls. Expression of a disintegrin and metalloproteinases (ADAMs) 10 and 17, which convert transmembrane fractalkine into the soluble form, was significantly increased in these cases. Incubation of first-trimester placental explants with TNF-? provoked a significant increase in fractalkine expression and release of the soluble form, whereas IL-6 had no effect. TNF-?-mediated up-regulation of placental fractalkine was reversed in the presence of the aspirin-derivative salicylate, which impaired activation of NF-?B p65 in TNF-?-treated explants. On the basis of data from placental explants, we suggest that increased maternal TNF-? may up-regulate the expression and release of placental fractalkine, which, in turn, may contribute to an exaggerated systemic inflammatory response in PE. PMID:25769431

  7. Placental fractalkine is up-regulated in severe early onset preeclampsia

    PubMed Central

    Siwetz, Monika; Dieber-Rotheneder, Martina; Cervar-Zivkovic, Mila; Kummer, Daniel; Kremshofer, Julia; Weiss, Gregor; Herse, Florian; Huppertz, Berthold; Gauster, Martin

    2015-01-01

    The pathogenesis of preeclampsia includes the release of placental factors into the maternal circulation inducing an inflammatory environment in the mother. One of the factors may be the pro-inflammatory chemokine fractalkine, which is expressed in the syncytiotrophoblast of human placenta, from where it is released into the maternal circulation by constitutive shedding. We examined whether placental fractalkine is up-regulated in severe early onset preeclampsia and whether the pro-inflammatory cytokines tumor necrosis factor (TNF)-? and interleukin-6 are able to increase the expression of fractalkine. Gene expression analysis, ELISA, and immunohistochemistry consistently showed increased fractalkine expression in placentas from severe early onset preeclampsia, compared to gestational age-matched controls. Expression of the metalloproteinases ADAM10 and ADAM17, which convert transmembrane fractalkine into the soluble form, was significantly increased in these cases. Incubation of first trimester placental explants with TNF-? provoked a significant increase in fractalkine expression and release of the soluble form, whereas interleukin-6 had no effect. TNF-?-mediated up-regulation of placental fractalkine was reversed in the presence of the Aspirin-derivative salicylate, which impaired activation of NF-?B p65 in TNF-?-treated explants. Based on data from placental explants we suggest that increased maternal TNF-? may up-regulate the expression and release of placental fractalkine, which in turn may contribute to an exaggerated systemic inflammatory response in preeclampsia. PMID:25769431

  8. Metformin upregulates E-cadherin and inhibits B16F10 cell motility, invasion and migration

    PubMed Central

    LIANG, GUANZHAO; DING, MINGLEI; LU, HAITAO; CAO, NA; NIU, YANDONG; GAO, YANG; LU, JIE

    2015-01-01

    Malignant melanoma is a highly metastatic cancer, and has a poor prognosis once metastasis has occurred. E-cadherin downregulation is associated with a poorer prognosis in various types of cancer, including lung, ovarian, cervical and prostate. In the majority of cancer cell lines, E-cadherin upregulation inhibits cell motility, migration and invasiveness, and reduces tumor metastasis in in vivo models. In the present study, the inhibitory effects of metformin on the motility, invasion and migration of the B16F10 murine melanoma cell line, and the possible molecular mechanisms underlying this effect were investigated. B16F10 cells were treated with various concentrations of metformin for 24 h and their motility, migration and invasion were tested using a wound-healing assay, a migration assay and a matrigel invasion assay, respectively. Furthermore, the expression of E-cadherin was measured by immunocytochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction. The results showed that metformin effectively upregulated the expression of E-cadherin, and inhibited B16F10 cell motility, migration and invasion, in a dose-dependent manner. This suggested that the inhibition of motility, migration and invasion of B16F10 cells by metformin may be associated with the upregulation of E-cadherin expression, indicating that metformin may have a role in the treatment of melanoma. PMID:26622703

  9. P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest

    PubMed Central

    Shamseddine, A A; Clarke, C J; Carroll, B; Airola, M V; Mohammed, S; Rella, A; Obeid, L M; Hannun, Y A

    2015-01-01

    Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest. PMID:26512957

  10. Up-regulation of Bcl-2 by redox signals in glomerular mesangial cells.

    PubMed

    Sandau, K B; Brüne, B

    2000-01-01

    The mediators nitric oxide (NO) and superoxide (O2-) are known to regulate cell death and survival. In mesangial cells (MC), NO induced apoptosis and in higher concentrations necrosis. Intriguingly, cogeneration of NO and O2- in a balanced ratio promoted cell protection. Under these conditions, we noticed the accumulation of the anti-apoptotic protein Bcl-2. Its up-regulation is based on an increase in mRNA and protein level. To investigate whether oxidative stress elicits Bcl-2 expression in general, we further used the chemically unrelated oxidative agents diamide and butyl hydroperoxide. Both stimulated mRNA and protein up-regulation of Bcl-2. But in contrast to diamide, butyl hydroperoxide evoked apoptosis and necrosis despite Bcl-2 accumulation. As diamide was non-toxic, we used diamide as a Bcl-2 activator to protect MC against a subsequent toxic dose of NO. We conclude that redox changes promote Bcl-2 up-regulation that may confer cellular protection towards apoptosis. PMID:10713727

  11. Insecticide-Mediated Up-Regulation of Cytochrome P450 Genes in the Red Flour Beetle (Tribolium castaneum)

    PubMed Central

    Liang, Xiao; Xiao, Da; He, Yanping; Yao, Jianxiu; Zhu, Guonian; Zhu, Kun Yan

    2015-01-01

    Some cytochrome P450 (CYP) genes are known for their rapid up-regulation in response to insecticide exposures in insects. To date, however, limited information is available with respect to the relationships among the insecticide type, insecticide concentration, exposure duration and the up-regulated CYP genes. In this study, we examined the transcriptional response of eight selected CYP genes, including CYP4G7, CYP4Q4, CYP4BR3, CYP12H1, CYP6BK11, CYP9D4, CYP9Z5 and CYP345A1, to each of four insecticides in the red flour beetle, Tribolium castaneum. Reverse transcription quantitative PCR (RT-qPCR) revealed that CYP4G7 and CYP345A1 can be significantly up-regulated by cypermethrin (1.97- and 2.06-fold, respectively), permethrin (2.00- and 2.03-fold) and lambda-cyhalothrin (1.73- and 1.81-fold), whereas CYP4BR3 and CYP345A1 can be significantly up-regulated by imidacloprid (1.99- and 1.83-fold) when 20-day larvae were exposed to each of these insecticides at the concentration of LC20 for 24 h. Our studies also showed that similar levels of up-regulation can be achieved for CYP4G7, CYP4BR3 and CYP345A1 by cypermethrin, permethrin, lambda-cyhalothrin or imidacloprid with approximately one fourth of LC20 in 6 h. Our study demonstrated that up-regulation of these CYP genes was rapid and only required low concentrations of insecticides, and the up-regulation not only depended on the CYP genes but also the type of insecticides. Our results along with those from previous studies also indicated that there were no specific patterns for predicting the up-regulation of specific CYP gene families based on the insecticide classification. PMID:25607733

  12. Uncoupling protein-2 up-regulation and enhanced cyanide toxicity are mediated by PPAR{alpha} activation and oxidative stress

    SciTech Connect

    Zhang, X.; Li, L.; Prabhakaran, K.; Zhang, L.; Leavesley, H.B.; Borowitz, J.L.; Isom, G.E.

    2007-08-15

    Uncoupling protein 2 (UCP-2) is an inner mitochondrial membrane proton carrier that modulates mitochondrial membrane potential ({delta}{psi}{sub m}) and uncouples oxidative phosphorylation. We have shown that up-regulation of UCP-2 by Wy14,643, a selective peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) agonist, enhances cyanide cytotoxicity. The pathway by which Wy14,643 up-regulates UCP-2 was determined in a dopaminergic cell line (N27 cells). Since dopaminergic mesencephalic cells are a primary brain target of cyanide, the N27 immortalized mesencephalic cell was used in this study. Wy14,643 produced a concentration- and time-dependent up-regulation of UCP-2 that was linked to enhanced cyanide-induced cell death. MK886 (PPAR{alpha} antagonist) or PPAR{alpha} knock-down by RNA interference (RNAi) inhibited PPAR{alpha} activity as shown by the peroxisome proliferator response element-luciferase reporter assay, but only partially decreased up-regulation of UCP-2. The role of oxidative stress as an alternative pathway to UCP-2 up-regulation was determined. Wy14,643 induced a rapid surge of ROS generation and loading cells with glutathione ethyl ester (GSH-EE) or pre-treatment with vitamin E attenuated up-regulation of UCP-2. On the other hand, RNAi knockdown of PPAR{alpha} did not alter ROS generation, suggesting a PPAR{alpha}-independent component to the response. Co-treatment with PPAR{alpha}-RNAi and GSH-EE blocked both the up-regulation of UCP-2 by Wy14,643 and the cyanide-induced cell death. It was concluded that a PPAR{alpha}-mediated pathway and an oxidative stress pathway independent of PPAR{alpha} mediate the up-regulation of UCP-2 and subsequent increased vulnerability to cyanide-induced cytotoxicity.

  13. Airborne fine particulate matter induces an upregulation of endothelin receptors on rat bronchi.

    PubMed

    Wang, Rong; Xiao, Xue; Cao, Lei; Shen, Zhen-Xing; Lei, Ying; Cao, Yong-Xiao

    2016-02-01

    Airborne fine particulate matter (PM2.5) is a risk factor for respiratory diseases. However, little is known about the effects of PM2.5 on bronchi. The present study investigated the effect of airborne PM2.5 on rat bronchi and the underlying mechanisms. Isolated rat bronchial segments were cultured for 24 h. Endothelin (ET) receptor-mediated contractile responses were recorded using a wire myograph. The mRNA and protein expression levels of ET receptors were studied using quantitative real-time PCR, Western blotting, and immunohistochemistry. The results demonstrated that ETA and ETB receptor agonists induced remarkable contractile responses on fresh and cultured bronchial segments. PM2.5 (1.0 or 3.0 ?g/ml) significantly enhanced ETA and ETB receptor-mediated contractile responses in bronchi with a markedly increased maximal contraction compared to the DMSO or fresh groups. PM2.5 increased the mRNA and protein expression levels of ETA and ETB receptors. U0126 (a MEK1/2 inhibitor) and SB203580 (a p38 inhibitor) significantly suppressed PM2.5-induced increases in ETB receptor-mediated contractile responses, mRNA and protein levels. SP600125 (a JNK inhibitor) and SB203580 significantly abrogated the PM2.5-induced enhancement of ETA receptor-mediated contraction and receptor expression. In conclusion, PM2.5 upregulates ET receptors in bronchi. ETB receptor upregulation is associated with MEK1/2 and p38 pathways, and the upregulation of ETA receptor is involved in JNK and p38 pathways. PMID:26618262

  14. Upregulation of Gene Expression in Reward-Modulatory Striatal Opioid Systems by Sleep Loss

    PubMed Central

    Baldo, Brian A; Hanlon, Erin C; Obermeyer, William; Bremer, Quentin; Paletz, Elliott; Benca, Ruth M

    2013-01-01

    Epidemiological studies have shown a link between sleep loss and the obesity ‘epidemic,' and several observations indicate that sleep curtailment engenders positive energy balance via increased palatable-food ‘snacking.' These effects suggest alterations in reward-modulatory brain systems. We explored the effects of 10 days of sleep deprivation in rats on the expression of striatal opioid peptide (OP) genes that subserve food motivation and hedonic reward, and compared effects with those seen in hypothalamic energy balance-regulatory systems. Sleep-deprived (Sleep-Dep) rats were compared with yoked forced-locomotion apparatus controls (App-Controls), food-restricted rats (Food-Restrict), and unmanipulated controls (Home-Cage). Detection of mRNA levels with in situ hybridization revealed a subregion-specific upregulation of striatal preproenkephalin and prodynorhin gene expression in the Sleep-Dep group relative to all other groups. Neuropeptide Y (NPY) gene expression in the hippocampal dentate gyrus and throughout neocortex was also robustly upregulated selectively in the Sleep-Dep group. In contrast, parallel gene expression changes were observed in the Sleep-Dep and Food-Restrict groups in hypothalamic energy-sensing systems (arcuate nucleus NPY was upregulated, and cocaine- and amphetamine-regulated transcript was downregulated), in alignment with leptin suppression in both groups. Together, these results reveal a novel set of sleep deprivation-induced transcriptional changes in reward-modulatory peptide systems, which are dissociable from the energy-balance perturbations of sleep loss or the potentially stressful effects of the forced-locomotion procedure. The recruitment of telencephalic food-reward systems may provide a feeding drive highly resistant to feedback control, which could engender obesity through the enhancement of palatable feeding. PMID:23864029

  15. Zinc pyrithione impairs zinc homeostasis and upregulates stress response gene expression in reconstructed human epidermis

    PubMed Central

    Lamore, Sarah D.

    2014-01-01

    Zinc ion homeostasis plays an important role in human cutaneous biology where it is involved in epidermal differentiation and barrier function, inflammatory and antimicrobial regulation, and wound healing. Zinc-based compounds designed for topical delivery therefore represent an important class of cutaneous therapeutics. Zinc pyrithione (ZnPT) is an FDA-approved microbicidal agent used worldwide in over-the-counter topical antimicrobials, and has also been examined as an investigational therapeutic targeting psoriasis and UVB-induced epidermal hyperplasia. Recently, we have demonstrated that cultured primary human skin keratinocytes display an exquisite sensitivity to nanomolar ZnPT concentrations causing induction of heat shock response gene expression and poly(ADP-ribose) polymerase (PARP)-dependent cell death (Cell Stress Chaperones 15:309–322, 2010). Here we demonstrate that ZnPT causes rapid accumulation of intracellular zinc in primary keratinocytes as observed by quantitative fluorescence microscopy and inductively coupled plasma mass spectrometry (ICP-MS), and that PARP activation, energy crisis, and genomic impairment are all antagonized by zinc chelation. In epidermal reconstructs (EpiDerm™) exposed to topical ZnPT (0.1–2% in Vanicream™), ICP-MS demonstrated rapid zinc accumulation, and expression array analysis demonstrated upregulation of stress response genes encoding metallothionein-2A (MT2A), heat shock proteins (HSPA6, HSPA1A, HSPB5, HSPA1L, DNAJA1, HSPH1, HSPD1, HSPE1), antioxidants (SOD2, GSTM3, HMOX1), and the cell cycle inhibitor p21 (CDKN1A). IHC analysis of ZnPT-treated EpiDerm™ confirmed upregulation of Hsp70 and TUNEL-positivity. Taken together our data demonstrate that ZnPT impairs zinc ion homeostasis and upregulates stress response gene expression in primary keratinocytes and reconstructed human epidermis, activities that may underlie therapeutic and toxicological effects of this topical drug. PMID:21424779

  16. Smac mimetic-induced upregulation of interferon-? sensitizes glioblastoma to temozolomide-induced cell death.

    PubMed

    Marschall, V; Fulda, S

    2015-01-01

    Inhibitor of apoptosis (IAP) proteins are frequently expressed at high levels in cancer cells and represent attractive therapeutic targets. We previously reported that the Smac (second mitochondria-derived activator of caspases) mimetic BV6, which antagonizes IAP proteins, sensitizes glioblastoma cells to temozolomide (TMZ)-induced cell death in a nuclear factor-?B (NF-?B)-dependent manner. However, BV6-induced NF-?B target genes responsible for this synergistic interaction have remained elusive. Using whole-genome gene expression profiling, we here identify BV6-stimulated, NF-?B-dependent transcriptional upregulation of interferon-? (IFN?) and IFN-mediated proapoptotic signaling as critical events that mediate BV6/TMZ-induced apoptosis. Knockdown of IFN? significantly rescues cells from BV6/TMZ-induced cell death. Similarly, silencing of the corresponding receptor IFN?/? receptor (IFNAR) confers a significant protection against apoptosis, demonstrating that IFN? and IFN signaling are required for BV6/TMZ-mediated cell death. Moreover, BV6 and TMZ cooperate to transcriptionally upregulate the proapoptotic B-cell lymphoma 2 family proteins Bax (Bcl-2-associated X protein) or Puma (p53-upregulated modulator of apoptosis). Knockdown of Bax or Puma significantly decreases BV6/TMZ-induced apoptosis, showing that both proteins are necessary for apoptosis. By identifying IFN? as a key mediator of BV6/TMZ-induced apoptosis, our study provides novel insights into the underlying molecular mechanisms of Smac mimetic-mediated chemosensitization with important implications for the development of novel treatment strategies for glioblastoma. PMID:26379193

  17. Heme oxygenase-1 upregulation modulates tone and fibroelastic properties of internal anal sphincter

    PubMed Central

    Krishna, Chadalavada Vijay; Singh, Jagmohan; Kumar, Sumit

    2014-01-01

    A compromise in the internal anal sphincter (IAS) tone and fibroelastic properties (FEP) plays an important role in rectoanal incontinence. Herein, we examined the effects of heme oxygenase (HO)-1 upregulation on these IAS characteristics in young rats. We determined the effect of HO-1 upregulator hemin on HO-1 mRNA and protein expressions and on basal IAS tone and its FEP before and after HO-1 inhibitor tin protoporphyrin IX. For FEP, we determined the kinetics of the IAS smooth muscle responses, by the velocities of relaxation, and recovery of the IAS tone following 0 Ca2+ and electrical field stimulation. To characterize the underlying signal transduction for these changes, we determined the effects of hemin on RhoA-associated kinase (RhoA)/Rho kinase (ROCK) II, myosin-binding subunit of myosin light chain phosphatase 1, fibronectin, and elastin expression levels. Hemin increased HO-1 mRNA and protein similar to the increases in the basal tone, and in the FEP of the IAS. Underlying mechanisms in the IAS characteristics are associated with increases in the genetic and translational expressions of RhoA/ROCKII, and elastin. Fibronectin expression levels on the other hand were found to be decreased following HO-1 upregulation. The results of our study show that the hemin/HO-1 system regulates the tone and FEP of IAS. The hemin/HO-1 system thus provides a potential target for the development of new interventions aimed at treatment of gastrointestinal motility disorders, specifically the age-related IAS dysfunction. PMID:25035109

  18. Different Epigenetic Alterations Are Associated with Abnormal IGF2/Igf2 Upregulation in Neural Tube Defects

    PubMed Central

    Bai, Baoling; Zhang, Qin; Liu, Xiaozhen; Miao, Chunyue; Shangguan, Shaofang; Bao, Yihua; Guo, Jin; Wang, Li; Zhang, Ting; Li, Huili

    2014-01-01

    The methylation status of DNA methylation regions (DMRs) of the imprinted gene IGF2/Igf2 is associated with neural tube defects (NTDs), which are caused by a failure of the neural tube to fold and close and are the second-most common birth defect; however, the characterization of the expression level of IGF2/Igf2 in neural tissue from human fetuses affected with NTDs remains elusive. More importantly, whether abnormal chromatin structure also influences IGF2/Igf2 expression in NTDs is unclear. Here, we investigated the transcriptional activity of IGF2/Igf2 in normal and NTD spinal cord tissues, the methylation status of different DMRs, and the chromatin structure of the promoter. Our data indicated that in NTD samples from both human fetuses and retinoic acid (RA)-treated mouse fetuses, the expression level of IGF2/Igf2 was upregulated 6.41-fold and 1.84-fold, respectively, compared to controls. H19 DMR1, but not IGF2 DMR0, was hypermethylated in human NTD samples. In NTD mice, h19 DMR1 was stable, whereas the chromatin structure around the promoter of Igf2 might be loosened, which was displayed by higher H3K4 acetylation and lower H3K27 trimethylation. Therefore, the data revealed that IGF2/Igf2 expression can be ectopically up-regulated by dual epigenetic factors in NTDs. In detail, the upregulation of IGF2/Igf2 is likely controlled by hypermethylation of H19 DMR1 in human NTDs, however, in acute external RA-induced NTD mice it is potentially determined by more open chromatin structure. PMID:25423083

  19. Imaging upregulated brain arachidonic acid metabolism in HIV-1 transgenic rats

    PubMed Central

    Basselin, Mireille; Ramadan, Epolia; Igarashi, Miki; Chang, Lisa; Chen, Mei; Kraft, Andrew D; Harry, G Jean; Rapoport, Stanley I

    2011-01-01

    Human immunodeficiency virus (HIV)-associated infection involves the entry of virus-bearing monocytes into the brain, followed by microglial activation, neuroinflammation, and upregulated arachidonic acid (AA) metabolism. The HIV-1 transgenic (Tg) rat, a noninfectious HIV-1 model, shows neurologic and behavioral abnormalities after 5 months of age. We hypothesized that brain AA metabolism would be elevated in older HIV-1 Tg rats in vivo. Arachidonic acid incorporation from the plasma into the brain of unanesthetized 7-to-9-month-old rats was imaged using quantitative autoradiography, after [1-14C]AA infusion. Brain phospholipase (PLA2) activities and eicosanoid concentrations were measured, and enzymes were localized by immunostaining. AA incorporation coefficients k* and rates Jin, measures of AA metabolism, were significantly higher in 69 of 81 brain regions in HIV-1 Tg than in control rats, as were activities of cytosolic (c)PLA2-IV, secretory (s)PLA2, and calcium independent (i)PLA2-VI, as well as prostaglandin E2 and leukotriene B4 concentrations. Immunostaining of somatosensory cortex showed elevated cPLA2-IV, sPLA2-IIA, and cyclooxygenase-2 in neurons. Brain AA incorporation and other markers of AA metabolism are upregulated in HIV-1 Tg rats, in which neurologic changes and neuroinflammation have been reported. Positron emission tomography with [1-11C]AA could be used to test whether brain AA metabolism is upregulated in HIV-1-infected patients, in relation to cognitive and behavioral disturbances. PMID:20664612

  20. gamma-Glutamyl transpeptidase expression in Ewing's sarcoma cells: up-regulation by interferons.

    PubMed Central

    Bouman, Lena; Sancéau, Josiane; Rouillard, Dany; Bauvois, Brigitte

    2002-01-01

    The genetic hallmark of Ewing's sarcoma family of tumours (ET) is the presence of the translocation t(11;22)(q24;q12), which creates the ET fusion gene, leading to cellular transformation. Five human gamma-glutamyl transpeptidase (gamma-GT) genes are located near the chromosomal translocation in ET. gamma-GT is a major enzyme involved in glutathione homoeostasis. Five human cell lines representative of primary or metastatic tumours were investigated to study whether gamma-GT alterations could occur at the chromosomal breaks and rearrangements in ET. As shown by enzymic assays and FACS analyses, all ET cell lines consistently expressed a functional gamma-GT which however did not discriminate steps of ET progression. As shown previously [Sancéau, Hiscott, Delattre and Wietzerbin (2000) Oncogene 19, 3372-3383], ET cells respond to the antiproliferative effects of interferons (IFNs) type I (alpha and beta) and to a much less degree to IFN type II (gamma). IFN-alpha and -beta arrested cells in the S-phase of the cell cycle. We found an enhancement of gamma-GT mRNA species with IFN-alpha and -beta by reverse transcriptase-PCR analyses. This is reflected by up-regulation of gamma-GT protein, which coincides with the increase in gamma-GT-specific enzymic activity. Similarly, IFNs up-regulate the levels of gamma-GT in another IFN-responsive B cell line. Whether this up-regulation of gamma-GT by IFNs is of physiological relevance to cell behaviour remains to be studied. PMID:12049636

  1. Urban air pollution produces up-regulation of myocardial inflammatory genes and dark chocolate provides cardioprotection.

    PubMed

    Villarreal-Calderon, Rodolfo; Reed, William; Palacios-Moreno, Juan; Keefe, Sheyla; Herritt, Lou; Brooks, Diane; Torres-Jardón, Ricardo; Calderón-Garcidueñas, Lilian

    2012-05-01

    Air pollution is a serious environmental problem. Elderly subjects show increased cardiac morbidity and mortality associated with air pollution exposure. Mexico City (MC) residents are chronically exposed to high concentrations of fine particulate matter (PM(2.5)) and PM-associated lipopolysaccharides (PM-LPS). To test the hypothesis that chronic exposure to urban pollution produces myocardial inflammation, female Balb-c mice age 4 weeks were exposed for 16 months to two distinctly different polluted areas within MC: southwest (SW) and northwest (NW). SW mice were given either no treatment or chocolate 2g/9.5 mg polyphenols/3 times per week. Results were compared to mice kept in clean air. Key inflammatory mediator genes: cyclooxygenase-2 (COX-2), interleukin-1? (IL-1?), interleukin-6 (IL-6), and tumor necrosis factor-? (TNF-?), and the LPS receptor CD14 (cluster of differentiation antigen 14) were measured by real-time polymerase chain reaction. Also explored were target NF?B (nuclear factor ?B), oxidative stress and antioxidant defense genes. TNF-?, IL-6, and COX-2 were significantly increased in both NW and SWMC mice (p=0.0001). CD14 was up-regulated in SW mice in keeping with the high exposures to particulate matter associated endotoxin. Chocolate administration resulted in a significant down-regulation of TNF-? (p<0.0001), IL-6 (p=0.01), and IL-1? (p=0.02). The up-regulation of antioxidant enzymes and the down-regulation of potent oxidases, toll-like receptors, and pro-apoptotic signaling genes completed the protective profile. Exposure to air pollution produces up-regulation of inflammatory myocardial genes and endotoxin plays a key role in the inflammatory response. Regular consumption of dark chocolate may reduce myocardial inflammation and have cardioprotective properties in the setting of air pollution exposures. PMID:20932730

  2. Zinc pyrithione impairs zinc homeostasis and upregulates stress response gene expression in reconstructed human epidermis.

    PubMed

    Lamore, Sarah D; Wondrak, Georg T

    2011-10-01

    Zinc ion homeostasis plays an important role in human cutaneous biology where it is involved in epidermal differentiation and barrier function, inflammatory and antimicrobial regulation, and wound healing. Zinc-based compounds designed for topical delivery therefore represent an important class of cutaneous therapeutics. Zinc pyrithione (ZnPT) is an FDA-approved microbicidal agent used worldwide in over-the-counter topical antimicrobials, and has also been examined as an investigational therapeutic targeting psoriasis and UVB-induced epidermal hyperplasia. Recently, we have demonstrated that cultured primary human skin keratinocytes display an exquisite sensitivity to nanomolar ZnPT concentrations causing induction of heat shock response gene expression and poly(ADP-ribose) polymerase (PARP)-dependent cell death (Cell Stress Chaperones 15:309-322, 2010). Here we demonstrate that ZnPT causes rapid accumulation of intracellular zinc in primary keratinocytes as observed by quantitative fluorescence microscopy and inductively coupled plasma mass spectrometry (ICP-MS), and that PARP activation, energy crisis, and genomic impairment are all antagonized by zinc chelation. In epidermal reconstructs (EpiDerm™) exposed to topical ZnPT (0.1-2% in Vanicream™), ICP-MS demonstrated rapid zinc accumulation, and expression array analysis demonstrated upregulation of stress response genes encoding metallothionein-2A (MT2A), heat shock proteins (HSPA6, HSPA1A, HSPB5, HSPA1L, DNAJA1, HSPH1, HSPD1, HSPE1), antioxidants (SOD2, GSTM3, HMOX1), and the cell cycle inhibitor p21 (CDKN1A). IHC analysis of ZnPT-treated EpiDerm™ confirmed upregulation of Hsp70 and TUNEL-positivity. Taken together our data demonstrate that ZnPT impairs zinc ion homeostasis and upregulates stress response gene expression in primary keratinocytes and reconstructed human epidermis, activities that may underlie therapeutic and toxicological effects of this topical drug. PMID:21424779

  3. Histone Hyperacetylation Up-regulates Protein Kinase C? in Dopaminergic Neurons to Induce Cell Death

    PubMed Central

    Jin, Huajun; Kanthasamy, Arthi; Harischandra, Dilshan S.; Kondru, Naveen; Ghosh, Anamitra; Panicker, Nikhil; Anantharam, Vellareddy; Rana, Ajay; Kanthasamy, Anumantha G.

    2014-01-01

    The oxidative stress-sensitive protein kinase C? (PKC?) has been implicated in dopaminergic neuronal cell death. However, little is known about the epigenetic mechanisms regulating PKC? expression in neurons. Here, we report a novel mechanism by which the PKC? gene can be regulated by histone acetylation. Treatment with histone deacetylase (HDAC) inhibitor sodium butyrate (NaBu) induced PKC? expression in cultured neurons, brain slices, and animal models. Several other HDAC inhibitors also mimicked NaBu. The chromatin immunoprecipitation analysis revealed that hyperacetylation of histone H4 by NaBu is associated with the PKC? promoter. Deletion analysis of the PKC? promoter mapped the NaBu-responsive element to an 81-bp minimal promoter region. Detailed mutagenesis studies within this region revealed that four GC boxes conferred hyperacetylation-induced PKC? promoter activation. Cotransfection experiments and Sp inhibitor studies demonstrated that Sp1, Sp3, and Sp4 regulated NaBu-induced PKC? up-regulation. However, NaBu did not alter the DNA binding activities of Sp proteins or their expression. Interestingly, a one-hybrid analysis revealed that NaBu enhanced transcriptional activity of Sp1/Sp3. Overexpression of the p300/cAMP-response element-binding protein-binding protein (CBP) potentiated the NaBu-mediated transactivation potential of Sp1/Sp3, but expressing several HDACs attenuated this effect, suggesting that p300/CBP and HDACs act as coactivators or corepressors in histone acetylation-induced PKC? up-regulation. Finally, using genetic and pharmacological approaches, we showed that NaBu up-regulation of PKC? sensitizes neurons to cell death in a human dopaminergic cell model and brain slice cultures. Together, these results indicate that histone acetylation regulates PKC? expression to augment nigrostriatal dopaminergic cell death, which could contribute to the progressive neuropathogenesis of Parkinson disease. PMID:25342743

  4. Smac mimetic-induced upregulation of interferon-? sensitizes glioblastoma to temozolomide-induced cell death

    PubMed Central

    Marschall, V; Fulda, S

    2015-01-01

    Inhibitor of apoptosis (IAP) proteins are frequently expressed at high levels in cancer cells and represent attractive therapeutic targets. We previously reported that the Smac (second mitochondria-derived activator of caspases) mimetic BV6, which antagonizes IAP proteins, sensitizes glioblastoma cells to temozolomide (TMZ)-induced cell death in a nuclear factor-?B (NF-?B)-dependent manner. However, BV6-induced NF-?B target genes responsible for this synergistic interaction have remained elusive. Using whole-genome gene expression profiling, we here identify BV6-stimulated, NF-?B-dependent transcriptional upregulation of interferon-? (IFN?) and IFN-mediated proapoptotic signaling as critical events that mediate BV6/TMZ-induced apoptosis. Knockdown of IFN? significantly rescues cells from BV6/TMZ-induced cell death. Similarly, silencing of the corresponding receptor IFN?/? receptor (IFNAR) confers a significant protection against apoptosis, demonstrating that IFN? and IFN signaling are required for BV6/TMZ-mediated cell death. Moreover, BV6 and TMZ cooperate to transcriptionally upregulate the proapoptotic B-cell lymphoma 2 family proteins Bax (Bcl-2-associated X protein) or Puma (p53-upregulated modulator of apoptosis). Knockdown of Bax or Puma significantly decreases BV6/TMZ-induced apoptosis, showing that both proteins are necessary for apoptosis. By identifying IFN? as a key mediator of BV6/TMZ-induced apoptosis, our study provides novel insights into the underlying molecular mechanisms of Smac mimetic-mediated chemosensitization with important implications for the development of novel treatment strategies for glioblastoma. PMID:26379193

  5. Upregulation of gene expression in reward-modulatory striatal opioid systems by sleep loss.

    PubMed

    Baldo, Brian A; Hanlon, Erin C; Obermeyer, William; Bremer, Quentin; Paletz, Elliott; Benca, Ruth M

    2013-12-01

    Epidemiological studies have shown a link between sleep loss and the obesity 'epidemic,' and several observations indicate that sleep curtailment engenders positive energy balance via increased palatable-food 'snacking.' These effects suggest alterations in reward-modulatory brain systems. We explored the effects of 10 days of sleep deprivation in rats on the expression of striatal opioid peptide (OP) genes that subserve food motivation and hedonic reward, and compared effects with those seen in hypothalamic energy balance-regulatory systems. Sleep-deprived (Sleep-Dep) rats were compared with yoked forced-locomotion apparatus controls (App-Controls), food-restricted rats (Food-Restrict), and unmanipulated controls (Home-Cage). Detection of mRNA levels with in situ hybridization revealed a subregion-specific upregulation of striatal preproenkephalin and prodynorhin gene expression in the Sleep-Dep group relative to all other groups. Neuropeptide Y (NPY) gene expression in the hippocampal dentate gyrus and throughout neocortex was also robustly upregulated selectively in the Sleep-Dep group. In contrast, parallel gene expression changes were observed in the Sleep-Dep and Food-Restrict groups in hypothalamic energy-sensing systems (arcuate nucleus NPY was upregulated, and cocaine- and amphetamine-regulated transcript was downregulated), in alignment with leptin suppression in both groups. Together, these results reveal a novel set of sleep deprivation-induced transcriptional changes in reward-modulatory peptide systems, which are dissociable from the energy-balance perturbations of sleep loss or the potentially stressful effects of the forced-locomotion procedure. The recruitment of telencephalic food-reward systems may provide a feeding drive highly resistant to feedback control, which could engender obesity through the enhancement of palatable feeding. PMID:23864029

  6. KSHV encoded LANA upregulates Pim-1 and is a substrate for its kinase activity

    SciTech Connect

    Bajaj, Bharat G.; Verma, Subhash C.; Lan, Ke; Cotter, Murray A.; Woodman, Zenda L.; Robertson, Erle S. . E-mail: erle@mail.med.upenn.edu

    2006-07-20

    Pim kinases are proto-oncogenes that are upregulated in a number of B cell cancers, including Epstein-Barr Virus (EBV) associated Burkitt's lymphoma. They have also been shown to be upregulated in Kaposi sarcoma-associated herpes virus (KSHV) infected primary B cells. Most cells in KSHV-associated tumors are latently infected and express only a small subset of viral genes, with KSHV latency associated nuclear antigen (LANA) being constitutively expressed. LANA regulates the transcription of a large number of cellular and viral genes. Here, we show that LANA upregulates transcription from the Pim-1 promoter (pPim-1) and map this activation to a region in the promoter located within the sequence (-681 to +37). We show that LANA expressing cells can proliferate faster and are better protected from drug induced apoptosis. Since transition through cell cycle check points and anti-apoptosis are functions associated with Pim-1, it is likely that higher Pim-1 expression in cells expressing LANA is responsible, at least in part, for this effect. A Pim-1 phosphorylation site was also identified within the amino-terminal domain of LANA. Using in vitro kinase assays, we confirmed that LANA was indeed a Pim-1 substrate, and the failure of Pim-1 to phosphorylate LANA mutated at SS205/6RR identified this site as the specific serine residues phosphorylated by Pim-1. This report provides valuable insight into yet another cellular signaling pathway subverted by KSHV LANA and suggests a contribution to KSHV related oncogenesis.

  7. Erbb2 up-regulation of ADAM12 expression accelerates skin cancer progression.

    PubMed

    Rao, Velidi H; Vogel, Kristen; Yanagida, Jodi K; Marwaha, Nitin; Kandel, Amrit; Trempus, Carol; Repertinger, Susan K; Hansen, Laura A

    2015-10-01

    Solar ultraviolet (UV) radiation can cause severe damage to the skin and is the primary cause of most skin cancer. UV radiation causes DNA damage leading to mutations and also activates the Erbb2/HER2 receptor through indirect mechanisms involving reactive oxygen species. We hypothesized that Erbb2 activation accelerates the malignant progression of UV-induced skin cancer. Following the induction of benign squamous papillomas by UV exposure of v-ras(Ha) transgenic Tg.AC mice, mice were treated topically with the Erbb2 inhibitor AG825 and tumor progression monitored. AG825 treatment reduced tumor volume, increased tumor regression, and delayed the development of malignant squamous cell carcinoma (SCC). Progression to malignancy was associated with increased Erbb2 and ADAM12 (A Disintegin And Metalloproteinase 12) transcripts and protein, while inhibition of Erbb2 blocked the increase in ADAM12 message upon malignant progression. Similarly, human SCC and SCC cell lines had increased ADAM12 protein and transcripts when compared to normal controls. To determine whether Erbb2 up-regulation of ADAM12 contributed to malignant progression of skin cancer, Erbb2 expression was modulated in cultured SCC cells using forced over-expression or siRNA targeting, demonstrating up-regulation of ADAM12 by Erbb2. Furthermore, ADAM12 transfection or siRNA targeting revealed that ADAM12 increased both the migration and invasion of cutaneous SCC cells. Collectively, these results suggest Erbb2 up-regulation of ADAM12 as a novel mechanism contributing to the malignant progression of UV-induced skin cancer. Inhibition of Erbb2/HER2 reduced tumor burden, increased tumor regression, and delayed the progression of benign skin tumors to malignant SCC in UV-exposed mice. Inhibition of Erbb2 suppressed the increase in metalloproteinase ADAM12 expression in skin tumors, which in turn increased migration and tumor cell invasiveness. PMID:24798404

  8. ErbB2 Activation Upregulates Glutaminase 1 Expression Which Promotes Breast Cancer Cell Proliferation

    PubMed Central

    Qie, Shuo; Chu, Clarissa; Li, Weihua; Wang, Chenguang; Sang, Nianli

    2015-01-01

    Active glutamine utilization is critical for tumor cell proliferation. Glutaminolysis represents the first and rate-limiting step of glutamine utilization and is catalyzed by glutaminase (GLS). Activation of ErbB2 is one of the major causes of breast cancers, the second most common cause of death for women in many countries. However, it remains unclear whether ErbB2 signaling affects glutaminase expression in breast cancer cells. In this study, we show that MCF10A-NeuT cell line has higher GLS1 expression at both mRNA and protein levels than its parental line MCF10A, and knockdown of ErbB2 decreases GLS1 expression in MCF10A-NeuT cells. We further show that in these cells, ErbB2-mediated upregulation of GLS1 is not correlated to c-Myc expression. Moreover, activation of neither PI3K-Akt nor MAPK pathway is sufficient to upregulate GLS1 expression. Interestingly, inhibition of NF-?B blocks ErbB2-stimulated GLS1 expression, whereas stimulation of NF-?B is sufficient to enhance GLS1 levels in MCF10A cells, suggesting a PI3K-Akt-independent activation of NF-?B upregulates GLS1 in ErbB2-positive breast cancer cells. Finally, knockdown or inhibition of GLS1 significantly decreased the proliferation of breast cancer cells with high GLS1 levels. Taken together, our data indicate that ErbB2 activation promotes GLS1 expression via a PI3K-Akt-independent NF-?B pathway in breast cancer cells, identifying another oncogenic signaling pathway which stimulates GLS1 expression, and thus promoting glutamine utilization in cancer cells. These findings, if validated by in vivo model, may facilitate the identification of novel biochemical targets for cancer prevention and therapy. PMID:24122876

  9. Up-regulation of CYLD enhances Listeria monocytogenes induced apoptosis in THP-1 cells.

    PubMed

    Xu, Changzhi; Yang, Ling; Yuan, Yuan; Du, Fei; Wang, Shumin; Wang, Xiangfang; Zhu, Lin; Zhang, Buchang; Weaver, David

    2016-01-01

    Listeria monocytogenes (Lm), a facultative anaerobic gram-positive bacterium, causes listeriosis. Immune cell apoptosis is considered to be one pathogenic factor for listeriosis. As a deubiquitinase, CYLD is an important regulator both in innate immune response and apoptosis by negatively modulating NF-?B pathway. However the role of CYLD in Lm induced apoptosis remains unclear. Here we found that CYLD is significantly up-regulated in macrophages upon its infection. There is a moderate decrease in Lm proliferation and apoptotic cells in siRNA-induced CYLD knockdown THP-1 cells. Thereby CYLD may be involved in cell apoptosis mediated by Lm infection and its proliferation. PMID:26545866

  10. Localization and upregulation of survivin in cancer health disparities: a clinical perspective

    PubMed Central

    Khan, Salma; Ferguson Bennit, Heather; Asuncion Valenzuela, Malyn May; Turay, David; Diaz Osterman, Carlos J; Moyron, Ron B; Esebanmen, Grace E; Ashok, Arjun; Wall, Nathan R

    2015-01-01

    Survivin is one of the most important members of the inhibitors of apoptosis protein family, as it is expressed in most human cancers but is absent in normal, differentiated tissues. Lending to its importance, survivin has proven associations with apoptosis and cell cycle control, and has more recently been shown to modulate the tumor microenvironment and immune evasion as a result of its extracellular localization. Upregulation of survivin has been found in many cancers including breast, prostate, pancreatic, and hematological malignancies, and it may prove to be associated with the advanced presentation, poorer prognosis, and lower survival rates observed in ethnically diverse populations. PMID:26185415

  11. Mung bean decreases plasma cholesterol by up-regulation of CYP7A1.

    PubMed

    Yao, Yang; Hao, Liu; Shi, Zhenxing; Wang, Lixia; Cheng, Xuzhen; Wang, Suhua; Ren, Guixing

    2014-06-01

    Our results affirmed that supplementation of 1 or 2% mung bean could decrease plasma total cholesterol and triacylglycerol level. Mung bean increased mRNA 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase. Most importantly, mung bean increased not only the protein level of cholesterol-7?-hydroxylase (CYP7A1) but also mRNA CYP7A1. It was concluded that the hypocholesterolemic activity of mung bean was most probable mediated by enhancement of bile acid excretion and up-regulation of CYP7A1. PMID:24566846

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

    PubMed

    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 (P<0.01). The percentage of cleaved embryos at 48hpi was higher (P<0.01) with the TCG 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

  13. Formation of chloroplast protrusions and catalase activity in alpine Ranunculus glacialis under elevated temperature and different CO2/O2 ratios.

    PubMed

    Buchner, Othmar; Moser, Tim; Karadar, Matthias; Roach, Thomas; Kranner, Ilse; Holzinger, Andreas

    2015-11-01

    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 (CAT) and ascorbate peroxidase (APX) activities. Under natural irradiation, the relative proportion of chloroplasts with protrusions (rCP) was highest (58.7 %) after exposure to low CO2 (38 ppm) and was lowest (3.0 %) at high CO2 (10,000 ppm). The same relationship was found for CAT activity, which decreased from 34.7 nkat mg(-1) DW under low CO2 to 18.4 nkat mg(-1) DW under high CO2, while APX activity did not change significantly. When exposed to natural CO2 concentration (380 ppm) in darkness, CP formation was significantly lower (18.2 %) compared to natural solar irradiation (41.3 %). In summary, CP formation and CAT activity are significantly increased under conditions that favour photorespiration, while in darkness or at high CO2 concentration under light, CP formation is significantly lower, providing evidence for an association between CPs and photorespiration. PMID:25701381

  14. Eukaryotic Catalase-Peroxidase: The Role of the Trp-Tyr-Met Adduct in Protein Stability, Substrate Accessibility, and Catalysis of Hydrogen Peroxide Dismutation.

    PubMed

    Gasselhuber, Bernhard; Carpena, Xavi; Graf, Michael M H; Pirker, Katharina F; Nicolussi, Andrea; Sündermann, Axel; Hofbauer, Stefan; Zamocky, Marcel; Furtmüller, Paul G; Jakopitsch, Christa; Oostenbrink, Chris; Fita, Ignacio; Obinger, Christian

    2015-09-01

    Recently, it was demonstrated that bifunctional catalase-peroxidases (KatGs) are found not only in archaea and bacteria but also in lower eukaryotes. Structural studies and preliminary biochemical data of the secreted KatG from the rice pathogen Magnaporthe grisea (MagKatG2) suggested both similar and novel features when compared to those of the prokaryotic counterparts studied so far. In this work, we demonstrate the role of the autocatalytically formed redox-active Trp140-Tyr273-Met299 adduct of MagKatG2 in (i) the maintenance of the active site architecture, (ii) the catalysis of hydrogen peroxide dismutation, and (iii) the protein stability by comparing wild-type MagKatG2 with the single mutants Trp140Phe, Tyr273Phe, and Met299Ala. The impact of disruption of the covalent bonds between the adduct residues on the spectral signatures and heme cavity architecture was small. By contrast, loss of its integrity converts bifunctional MagKatG2 to a monofunctional peroxidase of significantly reduced thermal stability. It increases the accessibility of ligands due to the increased flexibility of the KatG-typical large loop 1 (LL1), which contributes to the substrate access channel and anchors at the adduct Tyr. We discuss these data with respect to those known from prokaryotic KatGs and in addition present a high-resolution structure of an oxoiron compound of MagKatG2. PMID:26290940

  15. Functional variants in the catalase and myeloperoxidase genes, ambient air pollution, and respiratory-related school absences: an example of epistasis in gene-environment interactions.

    PubMed

    Wenten, Madé; Gauderman, W James; Berhane, Kiros; Lin, Pi-Chu; Peters, John; Gilliland, Frank D

    2009-12-15

    The individual effect of functional single nucleotide polymorphisms within the catalase and myeloperoxidase genes (CAT and MPO) has been studied in relation to asthma; however, their interrelationship with ambient air pollution exposures has yet to be determined. The authors investigated the interrelationships between variants in CAT and MPO, ambient air pollutants, and acute respiratory illness. Health information, air pollution, and incident respiratory-related school absences were ascertained in January-June 1996 for 1,136 Hispanic and non-Hispanic white US elementary schoolchildren as part of the prospective Children's Health Study. Functional and tagging single nucleotide polymorphisms for the CAT and MPO loci were genotyped. The authors found epistasis between functional polymorphisms in the CAT/MPO loci, which differed by levels of oxidant-stress-producing air pollutants. Risk of respiratory-related school absences was elevated for children with the CAT (G/G) and MPO (G/A or A/A) genes (relative risk = 1.35, 95% confidence interval: 1.03, 1.77; P-interaction = 0.005). The epistatic effect of CAT and MPO variants was most evident in communities exhibiting high ambient ozone levels (P-interaction = 0.03). The association of respiratory-illness absences with functional variants in CAT and MPO that differ by air pollution levels illustrates the need to consider genetic epistasis in assessing gene-environment interactions. PMID:19897513

  16. Plasmonic Enzyme-Linked Immunosorbent Assay Using Nanospherical Brushes as a Catalase Container for Colorimetric Detection of Ultralow Concentrations of Listeria monocytogenes.

    PubMed

    Chen, Rui; Huang, Xiaolin; Xu, Hengyi; Xiong, Yonghua; Li, Yanbin

    2015-12-30

    Plasmonic enzyme-linked immunosorbent assay (pELISA) based on catalase (CAT)-mediated gold nanoparticle growth exhibits ultrahigh sensitivity for detecting disease-related biomarkers using sandwich formats. However, the limit of detection (LOD) of this strategy for Listeria monocytogenes is only around 10(3) CFU/mL, which considerably exceeds the amount of L. monocytogenes commonly present in food products (<100 CFU/g). Herein, we report an improved pELISA method for detection of L. monocytogenes at ultralow concentrations with the sandwich formats using silica nanoparticles carrying poly(acrylic acid) brushes as a "CAT container" to increase enzyme loading for enhancing the detection signal. Under optimal conditions, the proposed pELISA exhibits good specificity and excellent sensitivity for L. monocytogenes with a LOD of 8 × 10(1) CFU/mL in 0.01 M phosphate-buffered saline, via a reaction that can be discriminated by the naked eye. The LOD obtained by this method was 2 and 5 orders of magnitude lower than that of conventional CAT-based pELISA and horseradish peroxidase (HRP)-based conventional ELISA, respectively. Coupled with large-volume immunomagnetic separation, the LOD for L. monocytogenes-spiked lettuce samples reached 8 × 10(1) CFU/g. The improved pELISA also exhibited a great potential in detecting a single cell of L. monocytogenes in 100 ?L of solution. PMID:26646325

  17. Biological applications and effects of optical masers. Annual report, 16 March 1985-15 March 1986. [Superoxide dismutase and catalase injected intravenously

    SciTech Connect

    Ham, W.T.; Mueller, H.A.; Ruffolo, J.J.; Cleary, S.F.; Guerry, R.K.

    1987-03-01

    Evidence that superoxide dismutase (SOD) enhances and catalase (CAT) reduces blue light toxicity in the monkey retina when injected intravenously (i.v) was inconclusive, and it is surmized that i.v. injection is ineffective because these large enzymes have a short lifetime in the circulation and cannot penetrate the blood-retinal barrier. Repetitive eye exposures of trained monkeys to the borad spectrum 330-420 nm were terminated in February 1985 after 1,171 daily exposures in one animal and 584 in the other animal. To date, no lenticular anomalies have been noted. Both monkeys are being maintained in good health and examined with the biomicroscope at frequent intervals. Repetitive daily exposures for 21 days of 440, 475, and 533 nm light at the same retinal site in 3 monkeys have shown that photic maculopathy is cumulative on a daily basis, especially for 440-nm light. In one monkey, daily radiant exposures of 2.8 J.cm/sup -2/ resulted in the appearance of a lesion on the 20th day. Histologic data are presented for retinal lesions produced by 40-microsecond pulses of 647-nm laser light at a pulse repetition frequency (PRF) of 1600 Hz. Exposures were 10 s in duration at a peak power to the cornea of the monkey eye of 43 nW. The results are unusual in that the photoreceptors above the reinal pigment epithelium (RPE) are completely ablated. Possible mechanisms are discussed.

  18. Multiwalled carbon nanotubes dispersed in carminic acid for the development of catalase based biosensor for selective amperometric determination of H(2)O(2) and iodate.

    PubMed

    Periasamy, Arun Prakash; Ho, Ya-Hui; Chen, Shen-Ming

    2011-11-15

    We report the preparation of stable dispersion of multiwalled carbon nanotubes (MWCNTs) using carminic acid (CA) as a dispersing agent. The transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) results confirmed that MWCNT is well dispersed in CA aqueous solution and CA has been well adsorbed at MWCNT walls. Fourier transform infrared (FTIR) and UV-vis absorption spectra results also confirmed the adsorption of CA at MWCNT. To develop a highly selective amperometric biosensor for H(2)O(2) and iodate, the model enzyme catalase (CAT) was immobilized at CACNT modified glassy carbon electrode surface. The immobilized CAT exhibits well defined quasi reversible redox peaks at a formal potential (E°') of -0.559V in 0.05M pH 7 phosphate buffer solution (PBS). The proposed CAT/CACNT biosensor exhibits excellent amperometric response towards H(2)O(2) and iodate in the linear concentration range between 10?M to 3.2mM and 0.01-2.16mM. The sensitivity values are 287.98?AmM(-1)cm(-2) and 0.253mAmM(-1)cm(-2), respectively. Moreover, the developed CAT biosensor exhibits high affinity for H(2)O(2) and iodate with good selectivity. PMID:21900003

  19. Erythrocyte Superoxide Dismutase, Glutathione Peroxidase, and Catalase Activities and Risk of Coronary Heart Disease in Generally Healthy Women: A Prospective Study

    PubMed Central

    Yang, Shuman; Jensen, Majken K.; Rimm, Eric B.; Willett, Walter; Wu, Tianying

    2014-01-01

    Erythrocyte antioxidant enzymes are major circulating antioxidant enzymes in the oxidative stress defense system. Few prospective studies have assessed the association between these enzymes and the risk of coronary heart disease (CHD) in generally healthy adults. We conducted a prospective nested case-control study of CHD among 32,826 women at baseline with 15 years of follow-up from 1989 to 2004 in the Nurses' Health Study. We investigated the association of baseline erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities with the risk of CHD. A total of 365 cases and 728 controls were included in the analysis. Overall, the relative risks of CHD associated with 1–standard deviation higher SOD, GPx, and CAT activities were 1.07 (95% confidence interval (CI): 0.94, 1.22), 1.04 (95% CI: 0.91, 1.18), and 1.04 (95% CI: 0.92, 1.17), respectively. Multivariable adjustments did not change the associations appreciably. Fasting status did not modify the associations, with the exception that SOD activity was positively associated with the risk of CHD among participants who provided blood samples within 12 hours of fasting. Overall, activities of SOD, GPx, and CAT were not associated with CHD among women who were generally healthy at the time of blood collection. PMID:25156995

  20. Reverse Catalase Reaction: Dioxygen Activation via Two-Electron Transfer from Hydroxide to Dioxygen Mediated By a Manganese(III) Salen Complex.

    PubMed

    Kurahashi, Takuya

    2015-09-01

    Although atmospheric dioxygen is regarded as the most ideal oxidant, O2 activation for use in oxygenation reactions intrinsically requires a costly sacrificial reductant. The present study investigated the use of aqueous alkaline solution for O2 activation. A manganese(III) salen complex, Mn(III)(salen)(Cl), in toluene reacts with aqueous KOH solution under aerobic conditions, which yields a di-?-oxo dimanganese(IV) salen complex, [Mn(IV)(salen)]2(?-O)2. The (18)O isotope experiments show that (18)O2 is indeed activated to give [Mn(IV)(salen)]2(?-(18)O)2 via a peroxide intermediate. Interestingly, the (18)OH(-) ion in H2(18)O was also incorporated to yield [Mn(IV)(salen)]2(?-(18)O)2, which implies that a peroxide species is also generated from (18)OH(-). The addition of benzyl alcohol as a stoichiometric reductant selectively inhibits the (18)O incorporation from (18)OH(-), indicating that the reaction of Mn(III)(salen)(Cl) with OH(-) supplies the electrons for O2 reduction. The conversion of both O2 and OH(-) to a peroxide species is exactly the reverse of a catalase-like reaction, which has a great potential as the most efficient O2 activation. Mechanistic investigations revealed that the reaction of Mn(III)(salen)(Cl) with OH(-) generates a transient species with strong reducing ability, which effects the reduction of O2 by means of a manganese(II) intermediate. PMID:26347290

  1. RNAi-Mediated Knockdown of Catalase Causes Cell Cycle Arrest in SL-1 Cells and Results in Low Survival Rate of Spodoptera litura (Fabricius)

    PubMed Central

    Hu, Meiying; Chen, Shaohua; Muhammad, Rizwan-ul-Haq; Dong, Xiaolin; Gong, Liang

    2013-01-01

    Deregulated reactive oxygen species (ROS) production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT) is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444) was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT). This study implied that ROS scavenging by CAT is important for S. litura survival. PMID:23555693

  2. Cyclic stretch induces upregulation of endothelin-1 with keratinocytes in vitro: Possible role in mechanical stress-induced hyperpigmentation

    SciTech Connect

    Kurita, Masakazu; Okazaki, Mutsumi; Fujino, Takashi; Takushima, Akihiko; Harii, Kiyonori

    2011-05-27

    Highlights: {yields} Influence of cyclic stretch on melanogenetic paracrine cytokines was investigated. {yields} Keratinocyte-derived endothelin-1 was upregulated with cyclic stretch. {yields} Degree of upregulation increases dose-dependently. {yields} This upregulation possibly plays a role in the pathogenesis of pigmented disorders. -- Abstract: The aim of this study was to investigate the possible pathological relation between mechanical stress and hyperpigmentation. We did this by investigating the influence of cyclic stretch on the expression of keratinocyte- and fibroblast-derived melanogenetic paracrine cytokines in vitro. Using primary human keratinocytes and fibroblasts, alterations of mRNA expression of melanogenetic paracrine cytokines due to cyclic stretch were investigated using a real-time polymerase chain reaction (PCR). The cytokines included basic fibroblast growth factor (bFGF), stem cell factor (SCF), granulocyte/macrophage colony-stimulating factor, interleukin-1{alpha}, and endothelin-1 (ET-1) for keratinocytes and bFGF, SCF, and hepatocyte growth factor for fibroblasts. The dose dependence of keratinocyte-derived ET-1 upregulation was further investigated using real-time PCR and an enzyme-linked immunosorbent assay. We also investigated the effects of cyclic stretch on the proliferation and differentiation of keratinocytes. Among the melanogenetic paracrine cytokines investigated, keratinocyte-derived ET-1 was consistently upregulated in all four cell lines. The degree of upregulation increased with the degree of the length and frequency of the stretch; in contrast, cell number and differentiation markers showed no obvious alterations with cyclic stretch. Keratinocyte-derived ET-1 upregulation possibly plays a significant role in the pathogenesis of pigmented disorders, such as friction melanosis, caused by mechanical stress.

  3. Senegenin Inhibits Hypoxia/Reoxygenation-Induced Neuronal Apoptosis by Upregulating RhoGDI?.

    PubMed

    Li, Xuemin; Zhao, Yandong; Liu, Panhong; Zhu, Xiaoqing; Chen, Minyi; Wang, Huadong; Lu, Daxiang; Qi, Renbin

    2015-12-01

    Neuronal apoptosis is an important event in hypoxia/reoxygenation (H/R)-induced neuronal injury. Senegenin (Sen), the predominant and most active component in Radix Polygalae root extracts, displays anti-apoptotic and anti-oxidative properties. Sen protects against H/R-induced neuronal apoptosis of highly differentiated PC12 cells and primary cortical neurons. Sen has also been investigated as a source of potential therapeutic targets. In this study, a proteomic approach was used to identify Sen-regulated proteins in PC12 cells. We found that Sen protected against H/R-induced neuronal apoptosis by upregulating RhoGDI? protein expression. The regulatory functions of RhoGDI? were investigated by knocking down RhoGDI? expression in PC12 cells using small interfering RNA (siRNA), followed by quantification of apoptosis and then altering the expression levels of apoptosis-related proteins. Our data show that after silencing RhoGDI?, the neuroprotective effects of Sen on H/R-induced PC12 cell apoptosis were absent. Furthermore, RhoGDI? silencing alleviated the Sen-mediated inhibition of the JNK pathway. Therefore, these findings indicated that Sen attenuates H/R-induced neuronal apoptosis by upregulating RhoGDI? expression and inhibiting the JNK pathway. In addition to the mechanism underlying neuroprotective effects of Sen, RhoGDI? was identified as a putative target of Sen based on a primary rat cortical neuron model of H/R-induced injury. PMID:25367882

  4. Utrophin Up-Regulation by an Artificial Transcription Factor in Transgenic Mice

    PubMed Central

    Mattei, Elisabetta; Corbi, Nicoletta; Di Certo, Maria Grazia; Strimpakos, Georgios; Severini, Cinzia; Onori, Annalisa; Desantis, Agata; Libri, Valentina; Buontempo, Serena; Floridi, Aristide; Fanciulli, Maurizio; Baban, Dilair; Davies, Kay E.; Passananti, Claudio

    2007-01-01

    Duchenne Muscular Dystrophy (DMD) is a severe muscle degenerative disease, due to absence of dystrophin. There is currently no effective treatment for DMD. Our aim is to up-regulate the expression level of the dystrophin related gene utrophin in DMD, complementing in this way the lack of dystrophin functions. To this end we designed and engineered several synthetic zinc finger based transcription factors. In particular, we have previously shown that the artificial three zinc finger protein named Jazz, fused with the appropriate effector domain, is able to drive the transcription of a test gene from the utrophin promoter “A”. Here we report on the characterization of Vp16-Jazz-transgenic mice that specifically over-express the utrophin gene at the muscular level. A Chromatin Immunoprecipitation assay (ChIP) demonstrated the effective access/binding of the Jazz protein to active chromatin in mouse muscle and Vp16-Jazz was shown to be able to up-regulate endogenous utrophin gene expression by immunohistochemistry, western blot analyses and real-time PCR. To our knowledge, this is the first example of a transgenic mouse expressing an artificial gene coding for a zinc finger based transcription factor. The achievement of Vp16-Jazz transgenic mice validates the strategy of transcriptional targeting of endogenous genes and could represent an exclusive animal model for use in drug discovery and therapeutics. PMID:17712422

  5. Dietary sphingolipids improve skin barrier functions via the upregulation of ceramide synthases in the epidermis.

    PubMed

    Duan, Jingjing; Sugawara, Tatsuya; Hirose, Mayumi; Aida, Kazuhiko; Sakai, Shota; Fujii, Aoi; Hirata, Takashi

    2012-06-01

    Sphingolipids are ubiquitous in eukaryotic organisms and are significant components in foods. It has been reported that treatment with sphingolipids prevents colon cancer, improves skin barrier function and suppresses inflammatory responses. However, the mechanisms for those effects of dietary sphingolipids are not well understood. In this study, to investigate the effects of dietary glucosylceramide (GluCer) and sphingomyelin (SM) on skin function, we characterized the recovery of skin barrier function and the change in sphingolipid metabolism-related enzymes in the epidermis using a special Mg-deficient diet-induced atopic dermatitis-like skin and tape-stripping damaged skin murine models. Our results show that dietary GluCer and SM accelerate the recoveries of damaged skin barrier functions. Correspondingly, dietary sphingolipids significantly upregulated the expression of ceramide synthases 3 and 4 in the epidermis of the atopic dermatitis-like skin model (P < 0.05). In the case of cultured cells, the expression of ceramide synthases 2-4 in normal human foreskin keratinocytes was significantly upregulated by treatment with 0.001-0.1 ?m sphingoid bases (sphinganine, sphingosine and trans-4,cis-8-sphingadienine) (P < 0.05). These results suggest that the effects of dietary sphingolipids might be due to the activation of ceramide synthesis in the skin, rather than the direct reutilization of dietary sphingolipids. Our findings provide a novel insight into the mechanisms of the skin barrier improving effect and a more comprehensive understanding of dietary sphingolipids. PMID:22621186

  6. Loss of MiR-664 Expression Enhances Cutaneous Malignant Melanoma Proliferation by Upregulating PLP2.

    PubMed

    Ding, Zhenhua; Jian, Sun; Peng, Xuebiao; Liu, Yimin; Wang, Jianyu; Zheng, Li; Ou, Chengshan; Wang, Yinghui; Zeng, Weixia; Zhou, Meijuan

    2015-08-01

    Proteolipid protein 2 (PLP2) has been shown to be upregulated in several cancers, including breast cancer, hepatocellular carcinoma, osteosarcoma, and melanoma. PLP2 specifically binds to phosphatidylinositol 3 kinase to activate the protein kinase B pathway to enhance cell proliferation, adhesion, and invasion in melanoma cells. Therefore, we speculated that PLP2 exhibits oncogenic potential. However, the regulatory mechanisms of PLP2 in cancer cells remain unclear.Herein, we found that microRNA (miR)-664 expression was significantly downregulated in cutaneous malignant melanoma (CMM) cells and tissues compared with normal human melanocytes and benign melanocytic naevi. MiR-664 expression level was significantly correlated with patient survival. Ectopic expression of miR-664 reduced CMM cell proliferation and anchorage-independent growth, whereas the inhibition of miR-664 induced these effects. Furthermore, inhibition of miR-664 in CMM cells resulted in modulation of their entry into the G1/S transitional phase, which was caused by downregulation of the cyclin-dependent kinase inhibitor P21 and upregulation of the cell-cycle regulator cyclin D1. Moreover, we demonstrated that miR-664 downregulated PLP2 expression by directly targeting the PLP2 untranslated region.Taken together, our results suggest that miR-664 may play an important role in suppressing proliferation of CMM cells and present a novel mechanism of miR-mediated direct suppression of PLP2 expression in cancer cells. PMID:26287415

  7. Psychological stress induces chemoresistance in breast cancer by upregulating mdr1.

    PubMed

    Su, Fengxi; Ouyang, Nengyong; Zhu, Pengcheng; Ouyang, Nengtai; Jia, Weijuan; Gong, Chang; Ma, Xuexia; Xu, Huanbin; Song, Erwei

    2005-04-15

    Psychological distress reduces the efficacy of chemotherapy in breast cancer patients. The mechanism may be related to the altered neuronal or hormonal secretions during stress. Here, we reported that adrenaline, a hormone mediating the biological activities of stress, upregulates mdr1 gene expression in MCF-7 breast cancer cells via alpha(2)-adrenergic receptors in a dose-dependent manner. Mdr1 upregulation can be specifically inhibited by pretreatment with mdr1-siRNA. Consequently, adrenergic stimulation enhances the pump function of P-glycoprotein and confers resistance of MCF-7 cells to paclitaxel. In vivo, restraint stress increases mdr1 gene expression in the MCF-7 cancers that are inoculated subcutaneously into the SCID mice and provokes resistance to doxorubicin in the implanted tumors. The effect can be blocked by injection of yohimbine, an alpha(2)-adrenergic inhibitor, but not by metyrapone, a corticosterone synthesis blocker. Therefore, we conclude that breast cancers may develop resistance against chemotherapeutic drugs under psychological distress by over-expressing mdr1 via adrenergic stimulation. PMID:15752739

  8. Upregulation of aquaporin-3 is involved in keratinocyte proliferation and epidermal hyperplasia.

    PubMed

    Nakahigashi, Kyoko; Kabashima, Kenji; Ikoma, Akihiko; Verkman, Alan S; Miyachi, Yoshiki; Hara-Chikuma, Mariko

    2011-04-01

    Aquaporin-3 (AQP3) is a water/glycerol-transporting protein expressed in keratinocytes of the epidermis. We previously showed that AQP3-mediated transport of water and glycerol is involved in keratinocyte migration and proliferation, respectively. However, the involvement of AQP3 in epidermal hyperplasia in skin diseases, such as atopic dermatitis (AD), is unknown. In this study, we found significantly increased AQP3 transcript and protein expression in the epidermis of human AD lesions. The upregulation of AQP3 expression in human keratinocytes by transfection with human AQP3 DNA plasmid was associated with increased cellular glycerol and ATP, as well as increased cell proliferation. Among several cytokines and chemokines produced in the skin, CCL17, which is highly expressed in AD, was found to be a strong inducer of AQP3 expression and enhanced keratinocyte proliferation. In mouse AD models, AQP3 was strongly overexpressed in the epidermis in wild-type mice. Epidermal hyperplasia was reduced in AQP3-deficient mice, with a decreased number of proliferating keratinocytes. These results suggest the involvement of AQP3 in epidermal hyperplasia by a mechanism involving upregulated AQP3 expression and consequent enhancement of keratinocyte proliferation. PMID:21191421

  9. Upregulated dynorphin opioid peptides mediate alcohol-induced learning and memory impairment

    PubMed Central

    Kuzmin, A; Chefer, V; Bazov, I; Meis, J; Ögren, S O; Shippenberg, T; Bakalkin, G

    2013-01-01

    The dynorphin opioid peptides control glutamate neurotransmission in the hippocampus. Alcohol-induced dysregulation of this circuit may lead to impairments in spatial learning and memory. This study examines whether changes in the hippocampal dynorphin and glutamate systems are related, and contribute to impairment of spatial learning and memory in a rat model of cognitive deficit associated with alcohol binge drinking. Hippocampal dynorphins (radioimmunoassay) and glutamate (in vivo microdialysis) were analyzed in Wistar rats exposed to repeated moderate-dose ethanol bouts that impair spatial learning and memory in the Water Maze Task (WMT). The highly selective, long-acting ?-opioid receptor (KOR) antagonist nor-binaltorphimine (nor-BNI) was administered systemically or into the hippocampal CA3 region to test a role of dynorphins in alcohol-induced dysregulations in glutamate neurotransmission and behavior in the WMT. The ethanol treatment impaired learning and memory, upregulated dynorphins and increased glutamate overflow in the CA3 region. Administration of nor-BNI after cessation of ethanol exposure reversed ethanol-induced changes in glutamate neurotransmission in animals exposed to ethanol and normalized their performance in the WMT. The findings suggest that impairments of spatial learning and memory by binge-like ethanol exposure are mediated through the KOR activation by upregulated dynorphins resulting in elevation in glutamate levels. Selective KOR antagonists may correct alcohol-induced pathological processes, thus representing a novel pharmacotherapy for treating of ethanol-related cognitive deficits. PMID:24105441

  10. Honey constituents up-regulate detoxification and immunity genes in the western honey bee Apis mellifera.

    PubMed

    Mao, Wenfu; Schuler, Mary A; Berenbaum, May R

    2013-05-28

    As a managed pollinator, the honey bee Apis mellifera is critical to the American agricultural enterprise. Recent colony losses have thus raised concerns; possible explanations for bee decline include nutritional deficiencies and exposures to pesticides and pathogens. We determined that constituents found in honey, including p-coumaric acid, pinocembrin, and pinobanksin 5-methyl ether, specifically induce detoxification genes. These inducers are primarily found not in nectar but in pollen in the case of p-coumaric acid (a monomer of sporopollenin, the principal constituent of pollen cell walls) and propolis, a resinous material gathered and processed by bees to line wax cells. RNA-seq analysis (massively parallel RNA sequencing) revealed that p-coumaric acid specifically up-regulates all classes of detoxification genes as well as select antimicrobial peptide genes. This up-regulation has functional significance in that that adding p-coumaric acid to a diet of sucrose increases midgut metabolism of coumaphos, a widely used in-hive acaricide, by ?60%. As a major component of pollen grains, p-coumaric acid is ubiquitous in the natural diet of honey bees and may function as a nutraceutical regulating immune and detoxification processes. The widespread apicultural use of honey substitutes, including high-fructose corn syrup, may thus compromise the ability of honey bees to cope with pesticides and pathogens and contribute to colony losses. PMID:23630255

  11. Armet, a UPR-upregulated protein, inhibits cell proliferation and ER stress-induced cell death

    SciTech Connect

    Apostolou, Andria; Shen Yuxian; Liang Yan; Luo Jun; Fang Shengyun

    2008-08-01

    The accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes ER stress that initiates the unfolded protein response (UPR). UPR activates both adaptive and apoptotic pathways, which contribute differently to disease pathogenesis. To further understand the functional mechanisms of UPR, we identified 12 commonly UPR-upregulated genes by expression microarray analysis. Here, we describe characterization of Armet/MANF, one of the 12 genes whose function was not clear. We demonstrated that the Armet/MANF protein was upregulated by various forms of ER stress in several cell lines as well as by cerebral ischemia of rat. Armet/MANF was localized in the ER and Golgi and was also a secreted protein. Silencing Armet/MANF by siRNA oligos in HeLa cells rendered cells more susceptible to ER stress-induced death, but surprisingly increased cell proliferation and reduced cell size. Overexpression of Armet/MANF inhibited cell proliferation and improved cell viability under glucose-free conditions and tunicamycin treatment. Based on its inhibitory properties for both proliferation and cell death we have demonstrated, Armet is, thus, a novel secreted mediator of the adaptive pathway of UPR.

  12. Fractalkine-upregulated milk-fat globule EGF factor-8 protein in cultured rat microglia.

    PubMed

    Leonardi-Essmann, Fernando; Emig, Michael; Kitamura, Yoshihisa; Spanagel, Rainer; Gebicke-Haerter, Peter J

    2005-03-01

    Fractalkine is the only known member of the CX(3)C-chemokine family, and so is its receptor CX(3)CR1. Fractalkine, typically is expressed by neurons where it is inserted in the plasma membrane ("chemokine on a stalk"). It can, however, be clipped off by a specific enzyme and diffuse into the extracellular space. CX(3)CR1 is primarily expressed by microglia, the phagocytes of the brain. This study was aimed at studying gene expression changes in cultured rat microglia upon fractalkine stimulation using gene chip technology. Six genes turned out to be upregulated, amongst which milk-fat globule EGF factor-8 protein (MFG-E8) was the most surprising, but also the most revealing one. We hypothesize that it serves as a bridging molecule between apoptotic cells (neurons) and microglia. Since the docking to microglia is, in part, mediated by members of the integrin family, six of these molecules have been-post hoc-included in real-time PCR confirmations of chip results. Two of them-integrin alpha(2) and integrin beta(5)-were upregulated as well. These data provide a much closer look into molecular mechanisms involved in apoptosis of neurons and their removal by microglia. PMID:15710462

  13. Liriodenine induces the apoptosis of human laryngocarcinoma cells via the upregulation of p53 expression

    PubMed Central

    LI, LIANG; XU, YING; WANG, BINQUAN

    2015-01-01

    Laryngocarcinoma is one of the most aggressive cancers that affects the head and neck region. The survival rate of patients with laryngocarcinoma is low due to late metastases and the resistance of the disease to chemotherapy and radiotherapy. Liriodenine, an alkaloid extracted from a number of plant species, has demonstrated antitumor effects on multiple types of cancer. However, the effects of liriodenine upon laryngocarcinoma, and the underlying mechanisms, are yet to be elucidated. The present study therefore investigated the potential antitumor effects of liriodenine on HEp-2 human laryngocarcinoma cells in vitro and HEp-2-implanted nude mice in vivo. Liriodenine induced significant apoptosis and inhibition of cell migration in the HEp-2 cells. Furthermore, the rate of tumor growth in the HEp-2-implanted nude mice was inhibited by the administration of liriodenine. The potential mechanism underlying the antitumor effects of liriodenine may result from an upregulative effect upon p53 expression, which ultimately induces cellular apoptosis. By contrast, the downregulation of p53 significantly reduced the antitumor effects of liriodenine. Together, these results suggest that liriodenine exhibits potent antitumor activities in laryngocarcinoma HEp-2 cells, in vitro and in vivo, via the upregulation of p53 expression. Liriodenine may therefore be a potential therapy for the treatment of laryngocarcinoma. PMID:25663867

  14. Hypolipidemic activity of okra is mediated through inhibition of lipogenesis and upregulation of cholesterol degradation.

    PubMed

    Wang, Hong; Chen, Gu; Ren, Dandan; Yang, Shang-Tian

    2014-02-01

    Little is known about the hypolipidemic activity of okra; therefore, we investigated the hypolipidemic activity of okra and its interaction with gene expression of several key components involved in lipid homeostasis. Male C57BL/6 mice were randomly divided into three groups and fed with hyperlipidemic diet or two hyperlipidemic diets supplemented with 1% or 2% okra powder for eight weeks. Results demonstrated that okra dose-dependently decreased serum and hepatic total cholesterol and triglyceride, and enhanced fecal excretion of bile acids. Gene expression analysis revealed that okra upregulated cholesterol 7?-hydroxylase (CYP7A1) expression, downregulated expression of sterol regulatory element-binding protein 1c (SREBP1c) and fatty acid synthase (FAS), with no effect on sterol regulatory element-binding protein 2 (SREBP2), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), low-density lipoprotein receptor (LDLR) and carnitine palmitoyltransferase-1A (CPT1A). It was suggested that hypolipidemic activity of okra was mediated most likely by upregulation of cholesterol degradation through CYP7A1 and by inhibition of lipogenesis through SREBP1c and FAS. Okra raw and fractionated polysaccharide showed strong bile acid binding capacity in vitro, which may contribute to the hypolipidemic activity observed. In conclusion, okra has potential application in the management of hyperlipidemia and its associated metabolic disorders. PMID:23606408

  15. Upregulation of the gene encoding a cytoplasmic dynein intermediate chain in senescent human cells.

    PubMed

    Horikawa, I; Parker, E S; Solomon, G G; Barrett, J C

    2001-01-01

    Normal human somatic cells, unlike cancer cells, stop dividing after a limited number of cell divisions through the process termed cellular senescence or replicative senescence, which functions as a tumor-suppressive mechanism and may be related to organismal aging. By means of the cDNA subtractive hybridization, we identified eight genes upregulated during normal chromosome 3-induced cellular senescence in a human renal cell carcinoma cell line. Among them is the DNCI1 gene encoding an intermediate chain 1 of the cytoplasmic dynein, a microtubule motor that plays a role in chromosome movement and organelle transport. The DNCI1 mRNA was also upregulated during in vitro aging of primary human fibroblasts. In contrast, other components of cytoplasmic dynein showed no significant change in mRNA expression during cellular aging. Cell growth arrest by serum starvation, contact inhibition, or gamma-irradiation did not induce the DNCI1 mRNA, suggesting its specific role in cellular senescence. The DNCI1 gene is on the long arm of chromosome 7 where tumor suppressor genes and a senescence-inducing gene for a group of immortal cell lines (complementation group D) are mapped. This is the first report that links a component of molecular motor complex to cellular senescence, providing a new insight into molecular mechanisms of cellular senescence. PMID:11500918

  16. BMPER is upregulated by statins and modulates endothelial inflammation by ICAM-1

    PubMed Central

    Helbing, Thomas; Rothweiler, René; Heinke, Jennifer; Goetz, Lena; Diehl, Philipp; Zirlik, Andreas; Patterson, Cam; Bode, Christoph; Moser, Martin

    2010-01-01

    Objective Besides cholesterol lowering statins exert pleiotropic effects on endothelial cells. Bone morphogenetic proteins (BMPs) have recently been implicated in vascular inflammation and disease. We set out to investigate the effect of statins on BMPER, a novel member of the BMP pathway. Methods and Results Mevastatin enhanced BMPER expression in cultured endothelial cells in a time and concentration dependent manner as determined by immunocytochemistry, RT-PCR, and western blotting. Similar effects were observed in vitro and in vivo using simvastatin. Actinomycin D chase analysis and BMPER promoter reporter assays revealed that this is mostly a posttranscriptional event resulting in prolonged BMPER RNA half-life. We confirmed that the RhoA/Rock/actin pathway is involved using the specific pathway activator CNFY that prevented upregulation of BMPER expression by mevastatin and pathway inhibitors (C3-toxin, RhoAN19 mutant, fasudil, cytochalasin D) that enhanced BMPER expression. Increasing concentrations of BMPER exert antiinflammatory features in endothelial cells as reflected by ICAM-1 downregulation. Accordingly, silencing of BMPER enhances ICAM-1 expression. Furthermore mevastatin reduced the expression of proinflammatory BMP4, a well known direct interaction partner of BMPER. Conclusion Mevastatin modulates the BMP pathway by enhancing BMPER via the RhoA/Rock/actin pathway as well as by reducing BMP4 expression. BMP4 down- and BMPER upregulation contribute to the antiinflammatory pleiotropic effects of statins. PMID:20042706

  17. Molecular cloning and functional characterization of a mouse gene upregulated by lipopolysaccharide treatment reveals alternative splicing

    SciTech Connect

    Du, Kejun; Chen, Yaoming; Dai, Zongming; Bi, Yuan; Cai, Tongjian; Hou, Lichao; Chai, Yubo; Song, Qinghe; Chen, Sumin; Luo, Wenjing; Chen, Jingyuan

    2010-01-01

    Treatment of mouse cells with lipopolysaccharide (LPS) potently initiates an inflammatory response, but the underlying mechanisms are unclear. We therefore sought to characterize cDNA sequences of a new mouse LPS-responsive gene, and to evaluate the effects of MLrg. Full-length cDNAs were obtained from LPS-treated NIH3T3 cells. We report that the MLrg gene produces two alternative splice products (GenBank Accession Nos. (DQ316984) and (DQ320011)), respectively, encoding MLrgW and MLrgS polypeptides. Both proteins contain zinc finger and leucine zipper domains and are thus potential regulators of transcription. Expression of MLrgW and MLrgS were robustly upregulated following LPS treatment, and the proteins were localized predominantly in the nuclear membrane and cytoplasm. In stable transfectants over-expressing MLrgW the proportion of cells in G1 phase was significantly reduced, while in cells over-expressing MLrgS the proportion of cells in G2 was significantly increased; both proteins are thus potential regulators of cell cycle progression. Upregulation of MLrgW and MLrgS may be an important component of the LPS inflammatory pathway and of the host response to infection with GNB.

  18. Upregulation of podocyte-secreted angiopoietin-like-4 in diabetic nephropathy.

    PubMed

    Ma, Jing; Chen, Xiao; Li, Jian-Si; Peng, Lei; Wei, Shi-Yao; Zhao, Shi-Lei; Li, Tong; Zhu, Dan; He, Yi-Xin; Wei, Qiu-Ju; Li, Bing

    2015-06-01

    Podocyte injury plays a key role in the development of diabetic nephropathy (DN). Understanding the changes in podocyte structure and function in diabetes mellitus may lead to novel diagnostic tools and treatment strategies for DN. Albuminuria, histological alterations, and podocyte injury were detected at different time points in streptozotocin (STZ)-induced diabetic rats. Increased urinary albumin-to-creatinine ratios (ACR) and podocyte injury were significantly observed 4 weeks post-STZ injection. We determined the glomerular expression and distribution of angiopoietin-like 4 (Angptl4) by immunofluorescence and real-time PCR. Glomerular Angptl4 expression was mostly colocalized with synaptopodin, a podocyte marker, with substantial additional overlap with the glomerular basement membrane (GBM). This finding indicated that Angptl4 might be primarily secreted by podocytes and moved toward the GBM. Moreover, we observed by Western blot analysis and ELISA that the urinary Angptl4 level was gradually upregulated in both STZ-induced rats and diabetic patients with microalbuminuria and macroalbuminuria. We further found that the increased glomerular Angptl4 expression was closely related to the urinary ACR level and podocyte injury. In addition, the urinary Angptl4 expression was closely associated with albuminuria in the rats and patients with DN. This study is the first to show that podocyte-secreted Angptl4 is upregulated in DN and can be detected in urine. Angptl4 might function as a podocyte injury marker and could be a potential and novel diagnostic and therapeutic biomarker for DN. PMID:25424436

  19. Erythrocyte peripheral type benzodiazepine receptor/voltage-dependent anion channels are upregulated by Plasmodium falciparum.

    PubMed

    Bouyer, Guillaume; Cueff, Anne; Egée, Stéphane; Kmiecik, Justyna; Maksimova, Yelena; Glogowska, Edyta; Gallagher, Patrick G; Thomas, Serge L Y

    2011-08-25

    Plasmodium falciparum relies on anion channels activated in the erythrocyte membrane to ensure the transport of nutrients and waste products necessary for its replication and survival after invasion. The molecular identity of these anion channels, termed "new permeability pathways" is unknown, but their currents correspond to up-regulation of endogenous channels displaying complex gating and kinetics similar to those of ligand-gated channels. This report demonstrates that a peripheral-type benzodiazepine receptor, including the voltage dependent anion channel, is present in the human erythrocyte membrane. This receptor mediates the maxi-anion currents previously described in the erythrocyte membrane. Ligands that block this peripheral-type benzodiazepine receptor reduce membrane transport and conductance in P falciparum-infected erythrocytes. These ligands also inhibit in vitro intraerythrocytic growth of P falciparum. These data support the hypothesis that dormant peripheral-type benzodiazepine receptors become the "new permeability pathways" in infected erythrocytes after up-regulation by P falciparum. These channels are obvious targets for selective inhibition in anti-malarial therapies, as well as potential routes for drug delivery in pharmacologic applications. PMID:21795748

  20. Human septin 3 on chromosome 22q13.2 is upregulated by neuronal differentiation.

    PubMed

    Methner, A; Leypoldt, F; Joost, P; Lewerenz, J

    2001-04-27

    An expression sequence tag identified in a screen for genes upregulated by retinoic acid induced neuronal differentiation of the human teratocarcinoma cell line Ntera2/D1 was found in close genomic proximity to a region of high sequence homology to the septin subfamily of GTPase genes. We could show that the tag corresponds to the 3' untranslated region of this novel gene named septin 3 and cloned three isoforms A (2191 bp), B (4378 bp), and C (1896 bp) from human Ntera2/D1 cDNA. We present the genomic localization and organization on chromosome 22q13.2, a chromosomal hot spot for translocations implicated in leukemia. Interestingly, MSF the closest paralog of septin 3 is a fusion partner in a therapy-related acute myeloid leukemia. Quantitative PCR confirmed the upregulation of the putative septin by neuronal differentiation and northern blotting showed only one band corresponding to sep3B with a neurospecific expression pattern in adult human tissues. PMID:11322766

  1. Upregulation of emotion areas through neurofeedback with a focus on positive mood.

    PubMed

    Johnston, Stephen; Linden, D E J; Healy, D; Goebel, R; Habes, I; Boehm, S G

    2011-03-01

    Real-time functional magnetic resonance imaging can be used to feed back signal changes from the brain to participants such that they can train to modulate activation levels in specific brain areas. Here we present the first study combining up-regulation of brain areas for positive emotions with psychometric measures to assess the effect of successful self-regulation on subsequent mood. We localized brain areas associated with positive emotions through presentation of standardized pictures with positive valence. Participants up-regulated activation levels in their target area during specific periods, alternating with rest. Participants attained reliable self-control of the target area by the last of three seven-minute runs. This training effect was supported by an extensive network outside the targeted brain region, including higher sensory areas, paralimbic and orbitofrontal cortex. Self-control of emotion areas was not accompanied by clear changes in self-reported emotions; trend-level improvements on depression scores were counteracted by increases on measures of fatigue, resulting in no overall mood improvement. It is possible that benefits of self-control of emotion networks may only appear in people who display abnormal emotional homeostasis. The use of only a single, short, training session, overlap between positive and negative emotion networks and aversive reactions to the scanning environment may have prevented the detection of subtle changes in mood. PMID:21264651

  2. CREB Is Required for cAMP/PKA Signals Upregulating Neuropathy Target Esterase Expression

    PubMed Central

    Chen, Jia-Xiang

    2013-01-01

    Neuropathy target esterase (NTE), which has been proposed as the primary target of organophosphorus compounds that cause delayed neuropathy with degeneration of nerve axons, is expressed primarily in neural cells but is also detected in non-neural cells. However, little is known about the regulation of NTE gene in cells. We found that a cyclic-AMP (cAMP)-response element (CRE) exists in the 5? flanking sequence of NTE gene in HeLa cells, which implies that NTE may be regulated by the transcription factor cAMP-response element-binding protein (CREB). In the study, knockdown of CREB decreased the protein and mRNA levels of NTE and inhibited the upregulation by cAMP/PKA signaling. Moreover, we observed that knockdown of CREB significantly decreased luciferase activity of the NTE gene promoter, while it had no effect on that of the CREB binding sites of mutated NTE gene promoter and truncated NTE gene promoter lacking the CREB binding site. cAMP/PKA signals could increase NTE reporter gene activity, while knockdown of CREB inhibited the increase. We found that the transcription factor CREB can bind to the promoter sequence of NTE by chromatin immunoprecipitation. In conclusion, we provided evidence that CREB is required for cAMP/PKA signals upregulating NTE expression in HeLa cells. PMID:23517531

  3. Electroacupuncture Upregulates SIRT1-Dependent PGC-1? Expression in SAMP8 Mice.

    PubMed

    Dong, Weiguo; Quo, Wanqing; Wang, Feng; Li, Changzheng; Xie, Yongcai; Zheng, Xuehua; Shi, Hong

    2015-01-01

    BACKGROUND Abnormalities of brain energy metabolism are involved in Alzheimer disease (AD). Sirtuin 1 (SIRT1) is a class III histone deacetylase and activates peroxisome proliferator-activated receptor-? co-activator-1? (PGC-1?), which enhances mitochondrial biogenesis and energy homeostasis. Electroacupuncture (EA) has been reported to improve brain energy metabolism in AD. However, the effect of EA on SIRT1 and PGC-1? in AD remains unclear. MATERIAL AND METHODS ATP levels were measured using assay kits in the hippocampus and frontal cortex of senescence-accelerated mouse prone 8 (SAMP8) mice. Western blotting analysis and quantitative real-time RT-PCR were performed to measure the expression of SIRT1 and PGC-1a in the hippocampus of SAMP8 mice. PGC-1? acetylation was analyzed using immunoprecipitation. RESULTS Compared with senescence-accelerated resistant mice 1 (SAMR1) mice, SAMP8 mice had a decline in ATP levels and the expression of SIRT1 and PGC-1?. EA treatment improved ATP levels, upregulated the expression of SIRT1 and PGC-1?, and decreased PGC-1? acetylation. CONCLUSIONS These data suggest that EA improved brain energy metabolism, potentially associated with the upregulation of SIRT1-dependent PGC-1? expression. PMID:26530101

  4. Cornus officinalis Methanol Extract Upregulates Melanogenesis in Melan-a Cells

    PubMed Central

    Hwang, Ji Yeon; Lee, Jae Soon; Kim, Young Chul

    2015-01-01

    Cornus officinalis is widely distributed in Korea, and its fruit has been used to make as herbal drug for traditional medicine in Korea, Japan, and China because of its tonic, analgesic, and diuretic properties. However, the effects of C. officinalis methanol extract (COME) on melanogenesis remain poorly understood. We evaluated the melanogenic capability of COME in melan-a cells, which are immortalized mouse melanocytes. COME increased melanin synthesis in a dose-dependent manner. Treatment with 12.5 ?g/mL of COME significantly increased melanin content by 36.1% (p < 0.001) to a level even higher than that (31.6%) of 3-isobutyl-1-methyl-xanthine, a well-known pigmentation agent. COME also upregulated tyrosinase activity and its messenger RNA and protein expression. In addition, COME upregulated the expression of tyrosinase-related proteins 1 and 2 and microphthalmia-associated transcription factor-M messenger RNA expression. These results imply that COME may be appropriate for development as a natural product to treat hair graying. PMID:26191383

  5. Upregulation and CpG island hypomethylation of the TRF2 gene in human gastric cancer.

    PubMed

    Dong, Wenjie; Wang, Lifu; Chen, Xiaobing; Sun, Pinghu; Wu, Yunlin

    2010-04-01

    The telomere-binding protein TRF2 regulates both telomere protection and telomere length. The fact that TRF2 is up-regulated in some tumors indicates that TRF2 plays a role in cancer. However, the role of TRF2 in gastric cancer has not been fully understood. The aim of this study is to evaluate the expression pattern of TRF2 in gastric cancer and examine the potential mechanism of TRF2 regulation. Our study revealed that the expression of TRF2 analyzed by immunohistochemistry was significantly higher in gastric cancers compared to noncancerous tissues. Moreover, TRF2 methylation was detected in six of 30 (20%) primary gastric cancers and 18 of 30 (60%) paired normal tissues, and the downregulation of TRF2 was strongly correlated with the methylation status (P < 0.001). Our results suggest that hypomethylation might contribute to the upregulation of TRF2 in gastric cancers and this overexpression may play a role in the pathogenesis of gastric cancers. PMID:19399616

  6. The tumor suppressor RASSF10 is upregulated upon contact inhibition and frequently epigenetically silenced in cancer

    PubMed Central

    Richter, A M; Walesch, S K; Würl, P; Taubert, H; Dammann, R H

    2012-01-01

    The Ras association domain family (RASSF) comprises a group of tumor suppressors that are frequently epigenetically inactivated in various tumor entities and linked to apoptosis, cell cycle control and microtubule stability. In this work, we concentrated on the newly identified putative tumor suppressor RASSF10. Methylation analysis reveals RASSF10 promoter hypermethylation in lung cancer, head and neck (HN) cancer, sarcoma and pancreatic cancer. An increase in RASSF10 methylation from normal tissues, primary tumors to cancer cell lines was observed. Methylation was reversed by 5-aza-2'-deoxycytidine treatment leading to reexpression of RASSF10. We further show that overexpression of RASSF10 suppresses colony formation in cancer cell lines. In addition, RASSF10 is upregulated by cell–cell contact and regulated on promoter level as well as endogenously by forskolin, protein kinase A (PKA) and activator Protein 1 (AP-1), linking RASSF10 to the cAMP signaling pathway. Knockdown of the AP-1 member JunD interfered with contact inhibition induced RASSF10 expression. In summary, we found RASSF10 to be epigenetically inactivated by hypermethylation of its CpG island promoter in lung, HN, sarcoma and pancreatic cancer. Furthermore, our novel findings suggest that tumor suppressor RASSF10 is upregulated by PKA and JunD signaling upon contact inhibition and that RASSF10 suppresses growth of cancer cells. PMID:23552700

  7. RAD001 (everolimus) enhances TRAIL cytotoxicity in human leukemic Jurkat T cells by upregulating DR5.

    PubMed

    Lee, Myoung Woo; Kim, Dae Seong; Eom, Ji-Eun; Ko, Young Jong; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

    2015-08-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), either alone or in combination with other anti-cancer agents, is a promising new strategy for the treatment of cancer. However, aberrant PI3K/Akt/mTOR survival signaling may confer TRAIL resistance by altering the balance between pro- and anti-apoptotic proteins. In the present study, we showed that the Akt/mTOR inhibitor RAD001 (everolimus) induced cell death in a dose-dependent manner and enhanced TRAIL-induced apoptosis in human leukemic Jurkat T cells, which show PI3K/Akt/mTOR pathway activation and basal expression levels of death receptor (DR) 5 (TRAIL-R2). Investigation of the effect of RAD001 treatment on the expression of TRAIL receptors (TRAIL-Rs) in Jurkat T cells showed that RAD001 significantly upregulated DR5 by up to 51.22%, but not other TRAIL-Rs such as DR4 (TRAIL-R1), decoy receptor (DcR) 1 (TRAIL-R3), and DcR2 (TRAIL-R4). Pretreatment with DR5:Fc chimera abrogated the RAD001-induced increase of TRAIL cytotoxicity, indicating that the upregulation of DR5 by RAD001 plays a role in enhancing the susceptibility of Jurkat T cells to TRAIL. Our results indicate that combination treatment with RAD001 and TRAIL may be a novel therapeutic strategy in leukemia. PMID:26074143

  8. The stress-related hormone norepinephrine induced upregulation of Nix, contributing to ECM protein expression.

    PubMed

    Liu, Weili; Wang, Xinxing; Gong, Jingbo; Mei, Zhusong; Gao, Xiujie; Zhao, Yun; Ma, Jing; Qian, Lingjia

    2014-11-01

    Organ fibrosis has been viewed as a major medical problem that leads to progressive dysfunction of the organ and eventually the death of patients. Stress-related hormone norepinephrine (NE) has been reported to exert fibrogenic actions in the injured organ. Nix plays a critical role in pressure overload-induced cardiac remodeling and heart failure through mediating cardiomyocyte apoptosis. However, cardiac remodeling also includes fibrosis. Whether Nix is involved in stress-induced fibrosis remains unclear. The present study was designed to determine the role of Nix in NE-induced NIH/3T3 fibroblasts. The results showed that Nix was upregulated and closely associated with cell proliferation, collagen and fibronectin expression in NIH/3T3 fibroblasts following NE treatment. Overexpression of Nix promoted collagen and fibronectin expression, whereas the suppression of Nix resulted in a strong reduction in collagen and fibronectin expression. Moreover, the increases in collagen and fibronectin expression induced by NE were successively increased when Nix was overexpressed and reduced when Nix was inhibited. Furthermore, we demonstrated that the PKC activation is responsible for the upregulation of Nix induced by NE. Inhibition of Nix expression with ?-adrenoceptor antagonist, ?-adrenoceptor antagonist or PKC inhibitor attenuated NE-induced collagen and fibronectin expression. Our data revealed that Nix is a novel mediator of NE-induced fibrosis. Thus, it would provide a new insight into the development of effective preventative measures and therapies of tissue fibrosis. PMID:24803315

  9. Upregulating Nonneuronal Cholinergic Activity Decreases TNF Release from Lipopolysaccharide-Stimulated RAW264.7 Cells

    PubMed Central

    Lv, Yi; Hu, Sen; Lu, Jiangyang; Dong, Ning; Liu, Qian; Du, Minghua; Zhang, Huiping

    2014-01-01

    Nonneuronal cholinergic system plays a primary role in maintaining homeostasis. It has been proved that endogenous neuronal acetylcholine (ACh) could play an anti-inflammatory role, and exogenous cholinergic agonists could weaken macrophages inflammatory response to lipopolysaccharide (LPS) stimulation through activation of ?7 subunit-containing nicotinic acetylcholine receptor (?7nAChR). We assumed that nonneuronal cholinergic system existing in macrophages could modulate inflammation through autocrine ACh and expressed ?7nAChR on the cells. Therefore, we explored whether LPS continuous stimulation could upregulate the nonneuronal cholinergic activity in macrophages and whether increasing autocrine ACh could decrease TNF release from the macrophages. The results showed that, in RAW264.7 cells incubated with LPS for 20 hours, the secretion of ACh was significantly decreased at 4?h and then gradually increased, accompanied with the enhancement of ?7nAChR expression level. The release of TNF was greatly increased from RAW264.7 cells at 4?h and 8?h exposure to LPS; however, it was suppressed at 20?h. Upregulating choline acetyltransferase (ChAT) expression through ChAT gene transfection could enhance ACh secretion and reduce TNF release from the infected RAW264. 7cells. The results indicated that LPS stimulation could modulate the activity of nonneuronal cholinergic system of RAW264.7 cells. Enhancing autocrine ACh production could attenuate TNF release from RAW264.7 cells. PMID:24733966

  10. Activity-dependent upregulation of presynaptic kainate receptors at immature CA3-CA1 synapses.

    PubMed

    Clarke, Vernon R J; Molchanova, Svetlana M; Hirvonen, Teemu; Taira, Tomi; Lauri, Sari E

    2014-12-10

    Presynaptic kainate-type glutamate receptors (KARs) regulate glutamate release probability and short-term plasticity in various areas of the brain. Here we show that long-term depression (LTD) in the area CA1 of neonatal rodent hippocampus is associated with an upregulation of tonic inhibitory KAR activity, which contributes to synaptic depression and causes a pronounced increase in short-term facilitation of transmission. This increased KAR function was mediated by high-affinity receptors and required activation of NMDA receptors, nitric oxide (NO) synthetase, and postsynaptic calcium signaling. In contrast, KAR activity was irreversibly downregulated in response to induction of long-term potentiation in a manner that depended on activation of the TrkB-receptor of BDNF. Both tonic KAR activity and its plasticity were restricted to early stages of synapse development and were lost in parallel with maturation of the network due to ongoing BDNF-TrkB signaling. These data show that presynaptic KARs are targets for activity-dependent modulation via diffusible messengers NO and BDNF, which enhance and depress tonic KAR activity at immature synapses, respectively. The plasticity of presynaptic KARs in the developing network allows nascent synapses to shape their response to incoming activity. In particular, upregulation of KAR function after LTD allows the synapse to preferentially pass high-frequency afferent activity. This can provide a potential rescue from synapse elimination by uncorrelated activity and also increase the computational dynamics of the developing CA3-CA1 circuitry. PMID:25505341

  11. Loss of MiR-664 Expression Enhances Cutaneous Malignant Melanoma Proliferation by Upregulating PLP2

    PubMed Central

    Ding, Zhenhua; Jian, Sun; Peng, Xuebiao; Liu, Yimin; Wang, Jianyu; Zheng, Li; Ou, Chengshan; Wang, Yinghui; Zeng, Weixia; Zhou, Meijuan

    2015-01-01

    Abstract Proteolipid protein 2 (PLP2) has been shown to be upregulated in several cancers, including breast cancer, hepatocellular carcinoma, osteosarcoma, and melanoma. PLP2 specifically binds to phosphatidylinositol 3 kinase to activate the protein kinase B pathway to enhance cell proliferation, adhesion, and invasion in melanoma cells. Therefore, we speculated that PLP2 exhibits oncogenic potential. However, the regulatory mechanisms of PLP2 in cancer cells remain unclear. Herein, we found that microRNA (miR)-664 expression was significantly downregulated in cutaneous malignant melanoma (CMM) cells and tissues compared with normal human melanocytes and benign melanocytic naevi. MiR-664 expression level was significantly correlated with patient survival. Ectopic expression of miR-664 reduced CMM cell proliferation and anchorage-independent growth, whereas the inhibition of miR-664 induced these effects. Furthermore, inhibition of miR-664 in CMM cells resulted in modulation of their entry into the G1/S transitional phase, which was caused by downregulation of the cyclin-dependent kinase inhibitor P21 and upregulation of the cell-cycle regulator cyclin D1. Moreover, we demonstrated that miR-664 downregulated PLP2 expression by directly targeting the PLP2 untranslated region. Taken together, our results suggest that miR-664 may play an important role in suppressing proliferation of CMM cells and present a novel mechanism of miR-mediated direct suppression of PLP2 expression in cancer cells. PMID:26287415

  12. Intestinal Upregulation of Melanin-Concentrating Hormone in TNBS-Induced Enterocolitis in Adult Zebrafish

    PubMed Central

    Ziogas, Dimitrios C.; Karagiannis, Apostolos K. A.; Zhen, Aileen; Fraenkel, Paula; Kokkotou, Efi

    2013-01-01

    Background Melanin-concentrating hormone (MCH), an evolutionarily conserved appetite-regulating neuropeptide, has been recently implicated in the pathogenesis of inflammatory bowel disease (IBD). Expression of MCH is upregulated in inflamed intestinal mucosa in humans with colitis and MCH-deficient mice treated with trinitrobenzene-sulfonic acid (TNBS) develop an attenuated form of colitis compared to wild type animals. Zebrafish have emerged as a new animal model of IBD, although the majority of the reported studies concern zebrafish larvae. Regulation MCH expression in the adult zebrafish intestine remains unknown. Methods In the present study we induced enterocolitis in adult zebrafish by intrarectal administration of TNBS. Follow-up included survival analysis, histological assessment of changes in intestinal architecture, and assessment of intestinal infiltration by myeloperoxidase positive cells and cytokine transcript levels. Results Treatment with TNBS dose-dependently reduced fish survival. This response required the presence of an intact microbiome, since fish pre-treated with vancomycin developed less severe enterocolitis. At 6 hours post-challenge, we detected a significant influx of myeloperoxidase positive cells in the intestine and upregulation of both proinflammatory and anti-inflammatory cytokines. Most importantly, and in analogy to human IBD and TNBS-induced mouse experimental colitis, we found increased intestinal expression of MCH and its receptor in TNBS-treated zebrafish. Conclusions Taken together these findings not only establish a model of chemically-induced experimental enterocolitis in adult zebrafish, but point to effects of MCH in intestinal inflammation that are conserved across species. PMID:24376661

  13. Postnatal Estradiol Up-regulates Lung Nitric Oxide Synthases and Improves Lung Function in Bronchopulmonary Dysplasia

    PubMed Central

    McCurnin, Donald C.; Pierce, Richard A.; Willis, Brigham C.; Chang, Ling Yi; Yoder, Bradley A.; Yuhanna, Ivan S.; Ballard, Philip L.; Clyman, Ronald I.; Waleh, Nahid; Maniscalco, William; Crapo, James D.; Grubb, Peter H.; Shaul, Philip W.

    2009-01-01

    Rationale: Nitric oxide (NO) plays an important role in lung development and perinatal lung function, and pulmonary NO synthases (NOS) are decreased in bronchopulmonary dysplasia (BPD) following preterm birth. Fetal estradiol levels increase during late gestation and estradiol up-regulates NOS, suggesting that after preterm birth estradiol deprivation causes attenuated lung NOS resulting in impaired pulmonary function. Objective: To test the effects of postnatal estradiol administration in a primate model of BPD over 14 days after delivery at 125 days of gestation (term = 185 d). Methods: Cardiopulmonary function was assessed by echocardiography and whole body plethysmography. Lung morphometric and histopathologic analyses were performed, and NOS enzymatic activity and abundance were measured. Measurements and Main Results: Estradiol caused an increase in blood pressure and ductus arteriosus closure. Expiratory resistance and lung compliance were also improved, and this occurred before spontaneous ductal closure. Furthermore, both oxygenation and ventilation indices were improved with estradiol, and the changes in lung function and ventilatory support requirements persisted throughout the study period. Whereas estradiol had negligible effect on indicators of lung inflammation and on lung structure assessed after the initial 14 days of ventilatory support, it caused an increase in lung neuronal and endothelial NOS enzymatic activity. Conclusions: In a primate model of BPD, postnatal estradiol treatment had favorable cardiovascular impact, enhanced pulmonary function, and lowered requirements for ventilatory support in association with an up-regulation of lung NOS. Estradiol may be an efficacious postnatal therapy to improve lung function and outcome in preterm infants. PMID:19151197

  14. Electroacupuncture Upregulates SIRT1-Dependent PGC-1? Expression in SAMP8 Mice

    PubMed Central

    Dong, Weiguo; Guo, Wanqing; Wang, Feng; Li, Changzheng; Xie, Yongcai; Zheng, Xueha; Shi, Hong

    2015-01-01

    Background Abnormalities of brain energy metabolism are involved in Alzheimer disease (AD). Sirtuin 1 (SIRT1) is a class III histone deacetylase and activates peroxisome proliferator-activated receptor-? co-activator-1? (PGC-1?), which enhances mitochondrial biogenesis and energy homeostasis. Electroacupuncture (EA) has been reported to improve brain energy metabolism in AD. However, the effect of EA on SIRT1 and PGC-1? in AD remains unclear. Material/Methods ATP levels were measured using assay kits in the hippocampus and frontal cortex of senescence-accelerated mouse prone 8 (SAMP8) mice. Western blotting analysis and quantitative real-time RT-PCR were performed to measure the expression of SIRT1 and PGC-1? in the hippocampus of SAMP8 mice. PGC-1? acetylation was analyzed using immunoprecipitation. Results Compared with senescence-accelerated resistant mice 1 (SAMR1) mice, SAMP8 mice had a decline in ATP levels and the expression of SIRT1 and PGC-1?. EA treatment improved ATP levels, upregulated the expression of SIRT1 and PGC-1?, and decreased PGC-1? acetylation. Conclusions These data suggest that EA improved brain energy metabolism, potentially associated with the upregulation of SIRT1-dependent PGC-1? expression. PMID:26530101

  15. Acute leptin exposure reduces megalin expression and upregulates TGF?1 in cultured renal proximal tubule cells.

    PubMed

    Briffa, Jessica F; Grinfeld, Esther; Mathai, Michael L; Poronnik, Phillip; McAinch, Andrew J; Hryciw, Deanne H

    2015-02-01

    Increased leptin concentrations observed in obesity can lead to proteinuria, suggesting that leptin may play a role in obesity-related kidney disease. Obesity reduces activation of AMP-activated protein kinase (AMPK) and increases transforming growth factor-?1 (TGF-?1) expression in the kidney, leading to albuminuria. Thus we investigated if elevated leptin altered AMPK and TGF-?1 signaling in proximal tubule cells (PTCs). In opossum kidney (OK) PTCs Western blot analysis demonstrated that leptin upregulates TGF-?1 secretion (0.50?µg/ml) and phosphorylated AMPK? (at 0.25, and 0.50?µg/ml), and downregulates megalin expression at all concentrations (0.05-0.50?µg/ml). Using the AMPK inhibitor, Compound C, leptin exposure regulated TGF-?1 expression and secretion in PTCs via an AMPK mediated pathway. In addition, elevated leptin exposure (0.50?µg/ml) reduced albumin handling in OK cells independently of megalin expression. This study demonstrates that leptin upregulates TGF-?1, reduces megalin, and reduces albumin handling in PTCs by an AMPK mediated pathway. PMID:25478926

  16. Thioredoxin reductase 1 upregulates MCP-1 release in human endothelial cells

    SciTech Connect

    Liu, Zhen-Bo; Shen, Xun

    2009-09-04

    To know if thioredoxin reductase 1 (TrxR1) plays a role in antioxidant defense mechanisms against atherosclerosis, effect of TrxR1 on expression/release of monocyte chemoattractant protein (MCP-1) was investigated in activated human endothelial-like EAhy926 cells. The MCP-1 release and expression, cellular generation of reactive oxygen species (ROS), nuclear translocation and DNA-binding activity of NF-{kappa}B subunit p65 were assayed in cells either overexpressing recombinant TrxR1 or having their endogenous TrxR1 knocked down. It was found that overexpression of TrxR1 enhanced, while knockdown of TrxR1 reduced MCP-1 release and expression. Upregulation of MCP-1 by TrxR1 was associated with increasing generation of intracellular ROS generation, enhanced nuclear translocation and DNA-binding activity of NF-{kappa}B. Assay using NF-{kappa}B reporter revealed that TrxR1 upregulated transcriptional activity of NF-{kappa}B. This study suggests that TrxR1 enhances ROS generation, NF-{kappa}B activity and subsequent MCP-1 expression in endothelial cells, and may promote rather than prevent vascular endothelium from forming atherosclerotic plaque.

  17. Upregulation of translational machinery and distinct genetic subgroups characterise hyperdiploidy in multiple myeloma.

    PubMed

    Agnelli, Luca; Fabris, Sonia; Bicciato, Silvio; Basso, Dario; Baldini, Luca; Morabito, Fortunato; Verdelli, Donata; Todoerti, Katia; Lambertenghi-Deliliers, Giorgio; Lombardi, Luigia; Neri, Antonino

    2007-02-01

    Karyotypic instability, including numerical and structural chromosomal aberrations, represents a distinct feature of multiple myeloma (MM). About 40-50% of patients display hyperdiploidy, defined by recurrent trisomies of non-random chromosomes. To molecularly characterise hyperdiploid (H) and nonhyperdiploid (NH) MM, we analysed the gene expression profiles of 66 primary tumours, and used fluorescence in situ hybridisation to investigate the major chromosomal alterations. The differential expression of 225 genes mainly involved in protein biosynthesis, transcriptional machinery and oxidative phosphorylation distinguished the 28 H-MM from the 38 NH-MM cases. The 204 upregulated genes in H-MM mapped mainly to the chromosomes involved in hyperdiploidy, and the 29% upregulated genes in NH-MM mapped to 16q. The identified transcriptional fingerprint was robustly validated on a publicly available gene expression dataset of 64 MM cases; and the global expression modulation of regions on the chromosomes involved in hyperdiploidy was verified using a self-developed non-parametric statistical method. H-MM could be further divided into two distinct molecular and transcriptional entities, characterised by the presence of trisomy 11 and 1q-extracopies/chromosome 13 deletion respectively. These data reinforce the importance of combining molecular cytogenetics and gene expression profiling to define a genomic framework for the study of MM pathogenesis and clinical management. PMID:17367409

  18. Integrin ?v?3 and fibronectin upregulate Slug in cancer cells to promote clot invasion and metastasis

    PubMed Central

    Knowles, Lynn M.; Gurski, Lisa A.; Engel, Charlotte; Gnarra, James R.; Maranchie, Jodi K.; Pilch, Jan

    2013-01-01

    The blood clotting cascade is selectively involved in lung metastasis, but the reason for this selectivity is unclear. Here we show that tumor cells that metastasize predominantly to the lung, such as renal cell carcinoma (RCC) and soft tissue sarcoma (STS), have an inherent capacity to generate extensive invadopodia when embedded in a blood clot. Compared to other metastatic cancer cells tested, RCC and STS cells exhibited increased levels of expression of fibronectin and an activated form of the integrin ?v?3, which coordinately supported the generation of an elaborate fibronectin matrix and actin stress fibers in fibrin-embedded tumor cells. Together, fibronectin and ?v?3 induced upregulation of the transcription factor Slug, which mediates epithelial-mesenchymal transition (EMT) as well as fibrin invasion and lung metastasis. This mechanism is clinically significant, because primary cancer cells from patients with metastatic RCC strongly invaded fibrin and this correlated with fibronectin matrix formation and Slug expression. In contrast, tumor cells from patients with localized RCC were largely non-invasive. Together, our findings establish that activated integrin ?v?3 and fibronectin promote lung metastasis by upregulating Slug, defining a mechanism through which cancer cells can colonize blood clots in the lung vasculature. PMID:23966293

  19. ERK3 promotes endothelial cell functions by upregulating SRC-3/SP1-mediated VEGFR2 expression

    PubMed Central

    Wang, Wei; Bian, Ka; Vallabhaneni, Sreeram; Zhang, Bin; Wu, Ray-Chang; O'Malley, Bert W.; Long, Weiwen

    2014-01-01

    Despite a regain of interest recently in ERK3 kinase signaling, the molecular regulations of both ERK3 gene expression and protein kinase activity are still largely unknown. While it is shown that disruption of ERK3 gene causes neonatal lethality, cell type-specific functions of ERK3 signaling remain to be explored. In this study, we report that ERK3 gene expression is upregulated by cytokines through c-Jun in endothelial cells; c-Jun binds to the ERK3 gene and regulates its transcription. We further reveal a new role for ERK3 in regulating endothelial cell migration, proliferation and tube formation by upregulating SRC-3/SP-1-mediated VEGFR2 expression. The underlying molecular mechanism involves ERK3-stimulated formation of a transcriptional complex involving coactivator SRC-3, transcription factor SP-1 and the secondary coactivator CBP. Taken together, our study identified a molecular regulatory mechanism of ERK3 gene expression and revealed a previously unknown role of ERK3 in regulating endothelial cell functions. PMID:24585635

  20. Mechanical loading up-regulates early remodeling signals from osteocytes subjected to physical damage.

    PubMed

    Liu, Chao; Zhang, Xiaoqing; Wu, Michael; You, Lidan

    2015-12-16

    In the mineralized bone matrix, mechanical loading causes micrometer-sized cracks. These cracks trigger targeted remodeling along the micro-crack. Physical damage to osteocytes was shown to be involved in the initiation of this remodeling process. However, the role of subsequent mechanical loading osteocyte response to physical damage is unclear. In this study, we have designed and developed an in vitro cell model to study the impact of mechanical loading on osteocytes with physical damage. Specifically, a system was developed to create sub-cellular physical damage on MLO-Y4 osteocytes in vitro. This model re-created the spatial distribution of non-viable cells and VEGF expression around microdamage as reported in vivo. Using this system, the short term (24h) effects of fluid shear stress in regulation of osteocyte response to physical damage were investigated. We have observed that the mechanical stimuli had an additive effect in terms of COX-2, VEGF mRNA expressions, as well as PGE2, VEGF concentrations in the media. Interestingly, other inflammatory signals such as IL-6 and TNF-? did not change with these stimuli, at this time point. Moreover, fluid shear also had a modulating effect in regulation of osteoclast differentiation by osteocyte with physical damage. These results show that (1) subcellular physical damage upregulates remodeling signals in osteocytes at early time point, (2) mechanical loading substantially upregulates these signals for remodeling in osteocytes with physical damage. PMID:26596719

  1. The Green Tea Component (-)-Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity

    PubMed Central

    Lee, Hyeon-Ju; Byun, Catherine Jeonghae; Park, Jung-Hyun; Park, Jae Hoon; Cho, Ho-Seong; Cho, Sung-Jin; Jo, Sangmee Ahn; Jo, Inho

    2015-01-01

    The green tea component (-)-epigallocatechin-3-gallate (EGCG) has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As) or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC) at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose) polymerase (PARP), activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As) treatment significantly induced production of reactive oxygen species (ROS), which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK), which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity. PMID:26375285

  2. Genomic amplification upregulates estrogen-related receptor alpha and its depletion inhibits oral squamous cell carcinoma tumors in vivo.

    PubMed

    Tiwari, Ankana; Swamy, Shivananda; Gopinath, Kodaganur S; Kumar, Arun

    2015-01-01

    The ESRRA gene encodes a transcription factor and regulates several genes, such as WNT11 and OPN, involved in tumorigenesis. It is upregulated in several cancers, including OSCC. We have previously shown that the tumor suppressor miR-125a targets ESRRA, and its downregulation causes upregulation of ESRRA in OSCC. Upregulation of ESRRA in the absence of downregulation of miR-125a in a subset of OSCC samples suggests the involvement of an alternative mechanism. Using TaqMan(®) copy number assay, here we report for the first time that the genomic amplification of ESRRA causes its upregulation in a subset of OSCC samples. Ectopic overexpression of ESRRA led to accelerated cell proliferation, anchorage-independent cell growth and invasion, and inhibited apoptosis. Whereas, knockdown of ESRRA expression by siRNA led to reduced cell proliferation, anchorage-independent cell growth and invasion, and accelerated apoptosis. Furthermore, the delivery of a synthetic biostable ESRRA siRNA to OSCC cells resulted in regression of xenografts in nude mice. Thus, the genomic amplification of ESRRA is another novel mechanism for its upregulation in OSCC. Based on our in vitro and in vivo experiments, we suggest that targeting ESRRA by siRNA could be a novel therapeutic strategy for OSCC and other cancers. PMID:26639757

  3. Genomic amplification upregulates estrogen-related receptor alpha and its depletion inhibits oral squamous cell carcinoma tumors in vivo

    PubMed Central

    Tiwari, Ankana; Swamy, Shivananda; Gopinath, Kodaganur S.; Kumar, Arun

    2015-01-01

    The ESRRA gene encodes a transcription factor and regulates several genes, such as WNT11 and OPN, involved in tumorigenesis. It is upregulated in several cancers, including OSCC. We have previously shown that the tumor suppressor miR-125a targets ESRRA, and its downregulation causes upregulation of ESRRA in OSCC. Upregulation of ESRRA in the absence of downregulation of miR-125a in a subset of OSCC samples suggests the involvement of an alternative mechanism. Using TaqMan® copy number assay, here we report for the first time that the genomic amplification of ESRRA causes its upregulation in a subset of OSCC samples. Ectopic overexpression of ESRRA led to accelerated cell proliferation, anchorage-independent cell growth and invasion, and inhibited apoptosis. Whereas, knockdown of ESRRA expression by siRNA led to reduced cell proliferation, anchorage-independent cell growth and invasion, and accelerated apoptosis. Furthermore, the delivery of a synthetic biostable ESRRA siRNA to OSCC cells resulted in regression of xenografts in nude mice. Thus, the genomic amplification of ESRRA is another novel mechanism for its upregulation in OSCC. Based on our in vitro and in vivo experiments, we suggest that targeting ESRRA by siRNA could be a novel therapeutic strategy for OSCC and other cancers. PMID:26639757

  4. Upregulation of pirin expression by chronic cigarette smoking is associated with bronchial epithelial cell apoptosis

    PubMed Central

    Gelbman, Brian D; Heguy, Adriana; O'Connor, Timothy P; Zabner, Joseph; Crystal, Ronald G

    2007-01-01

    Background Cigarette smoke disrupts the protective barrier established by the airway epithelium through direct damage to the epithelial cells, leading to cell death. Since the morphology of the airway epithelium of smokers does not typically demonstrate necrosis, the most likely mechanism for epithelial cell death in response to cigarette smoke is apoptosis. We hypothesized that cigarette smoke directly up-regulates expression of apoptotic genes, which could play a role in airway epithelial apoptosis. Methods Microarray analysis of airway epithelium obtained by bronchoscopy on matched cohorts of 13 phenotypically normal smokers and 9 non-smokers was used to identify specific genes modulated by smoking that were associated with apoptosis. Among the up-regulated apoptotic genes was pirin (3.1-fold, p < 0.002), an iron-binding nuclear protein and transcription cofactor. In vitro studies using human bronchial cells exposed to cigarette smoke extract (CSE) and an adenovirus vector encoding the pirin cDNA (AdPirin) were performed to test the direct effect of cigarette smoke on pirin expression and the effect of pirin expression on apoptosis. Results Quantitative TaqMan RT-PCR confirmed a 2-fold increase in pirin expression in the airway epithelium of smokers compared to non-smokers (p < 0.02). CSE applied to primary human bronchial epithelial cell cultures demonstrated that pirin mRNA levels increase in a time-and concentration-dependent manner (p < 0.03, all conditions compared to controls). Overexpression of pirin, using the vector AdPirin, in human bronchial epithelial cells was associated with an increase in the number of apoptotic cells assessed by both TUNEL assay (5-fold, p < 0.01) and ELISA for cytoplasmic nucleosomes (19.3-fold, p < 0.01) compared to control adenovirus vector. Conclusion These observations suggest that up-regulation of pirin may represent one mechanism by which cigarette smoke induces apoptosis in the airway epithelium, an observation that has implications for the pathogenesis of cigarette smoke-induced diseases. PMID:17288615

  5. Up-regulation of CLDN1 in gastric cancer is correlated with reduced survival

    PubMed Central

    2013-01-01

    Background The genetic changes in gastric adenocarcinoma are extremely complex and reliable tumor markers have not yet been identified. There are also remarkable geographical differences in the distribution of this disease. Our aim was to identify the most differentially regulated genes in 20 gastric adenocarcinomas from a Norwegian selection, compared to matched normal mucosa, and we have related our findings to prognosis, survival and chronic Helicobacter pylori infection. Methods Biopsies from gastric adenocarcinomas and adjacent normal gastric mucosa were obtained from 20 patients immediately following surgical resection of the tumor. Whole genome, cDNA microarray analysis was performed on the RNA isolated from the sample pairs to compare the gene expression profiles between the tumor against matched mucosa. The samples were microscopically examined to classify gastritis. The presence of H. pylori was examined using microscopy and immunohistochemistry. Results 130 genes showed differential regulation above a predefined cut-off level. Interleukin-8 (IL-8) and Claudin-1 (CLDN1) were the most consistently up-regulated genes in the tumors. Very high CLDN1 expression in the tumor was identified as an independent and significant predictor gene of reduced post-operative survival. There were distinctly different expression profiles between the tumor group and the control mucosa group, and the histological subsets of mixed type, diffuse type and intestinal type cancer demonstrated further sub-clustering. Up-regulated genes were mapped to cell-adhesion, collagen-related processes and angiogenesis, whereas normal intestinal functions such as digestion and excretion were associated with down-regulated genes. We relate the current findings to our previous study on the gene response of gastric epithelial cells to H. pylori infection. Conclusions CLDN1 was highly up-regulated in gastric cancer, and CLDN1 expression was independently associated with a poor post-operative prognosis, and may have important prognostic value. IL-8 and CLDN1 may represent central links between the gene response seen in acute H. pylori infection of gastric epithelial cells, and ultimately gastric cancer. PMID:24321518

  6. Cell Stress Induces Upregulation of Osteopontin via the ERK Pathway in Type II Alveolar Epithelial Cells

    PubMed Central

    Kato, Aki; Okura, Takafumi; Hamada, Chizuru; Miyoshi, Seigo; Katayama, Hitoshi; Higaki, Jitsuo; Ito, Ryoji

    2014-01-01

    Osteopontin (OPN) is a multifunctional protein that plays important roles in cell growth, differentiation, migration and tissue fibrosis. In human idiopathic pulmonary fibrosis and murine bleomycin-induced lung fibrosis, OPN is upregulated in type II alveolar epithelial cells (AEC II). However, the mechanism of OPN induction in AEC II is not fully understood. In this study, we demonstrate the molecular mechanism of OPN induction in AEC II and elucidate the functions of OPN in AEC II and lung fibroblasts. Human lung adenocarcinoma cells (A549) and mouse alveolar epithelial cells (MLE12), used as type II alveolar epithelial cell lines for in vitro assays, and human pulmonary alveolar epithelial cells (HPAEpiC) were treated with either bleomycin, doxorubicin or tunicamycin. The mechanism of OPN induction in these cells and its function as a pro-fibrotic cytokine on A549 and lung fibroblasts were analyzed. The DNA damaging reagents bleomycin and doxorubicin were found to induce OPN expression in A549, MLE12 and HPAEpiC. OPN expression was induced via activation of the extracellular signal-regulated protein kinase (ERK)-dependent signaling pathway in A549 and MLE12. The endoplasmic reticulum (ER) stress-inducing reagent tunicamycin induced OPN mRNA expression in A549, MLE12 and HPAEpiC, and OPN mRNA expression was induced via activation of the ERK-dependent signaling pathway in A549 and MLE12. Another ER stress-inducing reagent thapsigargin induced the expression of OPN mRNA as well as the subsequent production of OPN in A549 and MLE12. Furthermore, OPN promoted the proliferation of A549 and the migration of normal human lung fibroblasts. Inhibition of OPN by small interference RNA or neutralizing antibody suppressed both of these responses. The results of this study suggest that cell stress induces the upregulation of OPN in AEC II by signaling through the ERK pathway, and that upregulated OPN may play a role in fibrogenesis of the lung. PMID:24963635

  7. Host genetic variations in glutathione-S-transferases, superoxide dismutases and catalase genes influence susceptibility to malaria infection in an Indian population.

    PubMed

    Fernandes, Rayzel C; Hasan, Marriyah; Gupta, Himanshu; Geetha, K; Rai, Padmalatha S; Hande, Manjunath H; D'Souza, Sydney C; Adhikari, Prabha; Brand, Angela; Satyamoorthy, Kapaettu

    2015-06-01

    Antioxidant enzymes can contribute to disease susceptibility or determine response to therapy in individuals with malaria. Genetic variations due to polymorphisms in host genes encoding antioxidant enzymes such as glutathione S-transferases-theta, mu, pi (GSTT, GSTM, GSTP), superoxide dismutases (SOD) and catalase (CAT), may therefore, influence inter-individual response to malaria pathology and propensity of infection caused by Plasmodium vivax (Pv) and Plasmodium falciparum (Pf). Therefore, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, we investigated the association of deletions of GSTT1 and GSTM1, single nucleotide polymorphisms (SNPs) of GSTP1 (rs1695), SOD1 (rs2234694), SOD2 (rs4880, rs1141718), SOD3 (rs2536512) and CAT (rs1001179) in individuals infected with Pf (n = 100) and Pv (n = 100) against healthy controls (n = 150). Our data suggest a significant role for GSTM1 deletions in complicated Pv (p = 0.0007) malaria with ODDs ratio 3.8 [with 95 % confidence interval (CI) 1.9-7.4]. The results also indicated that polymorphisms present in GSTP1, SOD1 and CAT genes may be associated with malaria susceptibility (p < 0.05), whereas SOD3 polymorphism may play a role in malarial resistance (p < 0.05). In addition, we observed significant SNP-SNP interactions with synergistic genetic effects in SOD2, SOD3 and CAT genes for Pv and in SOD2 and SOD3 genes for Pf. In conclusion, our results provide convincing evidence for a relationship between polymorphisms in host antioxidant enzymes and susceptibility to malaria infection. PMID:25573779

  8. Amplified amperometric aptasensor for selective detection of protein using catalase-functional DNA-PtNPs dendrimer as a synergetic signal amplification label.

    PubMed

    Zhang, Juan; Yuan, Yali; biXie, Shun; Chai, Yaqin; Yuan, Ruo

    2014-10-15

    In this work, we present a new strategy to construct an electrochemical aptasensor for sensitive detection of platelet-derived growth factor BB (PDGF-BB) based on the synergetic amplification of a three-dimensional (3D) nanoscale catalase (CAT) enzyme-functional DNA-platinum nanoparticles (PtNPs) dendrimer through autonomous layer-by-layer assembly. Firstly, polyamidoaminedendrimer (PAMAM) with a hyper-branched and three-dimensional structure was served as nanocarriers to coimmobilize a large number of PDGF-BB binding aptamer (PBA II) and ssDNA 1 (S1) to form PBA II-PAMAM-S1 bioconjugate. In the presence of PDGF-BB, the bioconjugate was self-assembled on the electrode by sandwich assay. Following that, the carried S1 propagated a chain reaction of hybridization events between CAT-PtNPs-S1 and CAT-PtNPs-ssDNA 2 (S2) to form a 3D nanoscale CAT-functional PtNPs-DNA dendrimer, which successfully immobilized substantial CAT enzyme and PtNPs with superior catalysis activity. In this process, the formed negatively charged double-helix DNA could cause the intercalation of hexaammineruthenium(III) chloride (RuHex) into the groove via electrostatic interactions. Thus, numerous RuHex redox probes and CAT were decorated inside/outside of the dendrimer. In the presence of H2O2 in electrolytic cell, the synergistic reaction of CAT and PtNPs towards electrocatalysis could further amplify electrochemical signal. Under optimal condition, the CAT-PtNPs-DNA dendrimer-based sensing system presented a linear dependence between the reduction peak currents and logarithm of PDGF-BB concentrations in the range of 0.00005-35 nM with a relatively low detection limit of 0.02 pM. PMID:24813911

  9. Hinokitiol Exerts Anticancer Activity through Downregulation of MMPs 9/2 and Enhancement of Catalase and SOD Enzymes: In Vivo Augmentation of Lung Histoarchitecture.

    PubMed

    Huang, Chien-Hsun; Jayakumar, Thanasekaran; Chang, Chao-Chien; Fong, Tsorng-Harn; Lu, Shing-Hwa; Thomas, Philip Aloysius; Choy, Cheuk-Sing; Sheu, Joen-Rong

    2015-01-01

    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 ?M) 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. PMID:26404213

  10. Roles of catalase (CAT) and ascorbate peroxidase (APX) genes in stress response of eggplant (Solanum melongena L.) against Cu(+2) and Zn(+2) heavy metal stresses.

    PubMed

    Soydam-Ayd?n, Semra; Büyük, ?lker; Cansaran-Duman, Demet; Aras, Sümer

    2015-12-01

    Eggplant (Solanum melongena L.) is a good source of minerals and vitamins and this feature makes its value comparable with tomato which is economically the most important vegetable worldwide. Due to its common usage as food and in medicines, eggplant cultivation has a growing reputation worldwide. But genetic yield potential of an eggplant variety is not always attained, and it is limited by some factors such as heavy metal contaminated soils in today's world. Today, one of the main objectives of plant stress biology and agricultural biotechnology areas is to find the genes involved in antioxidant stress response and engineering the key genes to improve the plant resistance mechanisms. In this regard, the current study was conducted to gain an idea on the roles of catalase (CAT) and ascorbate peroxidase (APX) genes in defense mechanism of eggplant (S. melongena L., Pala-49 (Turkish cultivar)) treated with different concentrations of Cu(+2) and Zn(+2). For this aim, the steady-state messenger RNA (mRNA) levels of CAT and APX genes were determined by quantitative real-time PCR (qRT-PCR) in stressed eggplants. The results of the current study showed that different concentrations of Cu(+2) and Zn(+2) stresses altered the mRNA levels of CAT and APX genes in eggplants compared to the untreated control samples. When the mRNA levels of both genes were compared, it was observed that CAT gene was more active than APX gene in eggplant samples subjected to Cu(+2) contamination. The current study highlights the importance of CAT and APX genes in response to Cu(+2) and Zn(+2) heavy metal stresses in eggplant and gives an important knowledge about this complex interaction. PMID:26530238

  11. Fetal nicotine exposure produces postnatal up-regulation of adenylate cyclase activity in peripheral tissues

    SciTech Connect

    Slotkin, T.A.; Navarro, H.A.; McCook, E.C.; Seidler, F.J. )

    1990-01-01

    Gestational exposure to nicotine has been shown to affect development of noradrenergic activity in both the central and peripheral nervous systems. In the current study, pregnant rats received nicotine infusions of 6 mg/kg/day throughout gestation, administered by osmotic minipump implants. After birth, offspring of the nicotine-infused dams exhibited marked increases in basal adenylate cyclase activity in membranes prepared from kidney and heart, as well as supersensitivity to stimulation by either a {beta}-adrenergic agonist, isoproterenol, or by forskolin. The altered responses were not accompanied by up-regulation of {beta}-adrenergic receptors: in fact, ({sup 125}I)pindolol binding was significantly decreased in the nicotine group. These results indicate that fetal nicotine exposure affects enzymes involved in membrane receptor signal transduction, leading to altered responsiveness independently of changes at the receptor level.

  12. Molecular cloning and functional analysis of a novel oncogene, cancer-upregulated gene 2 (CUG2)

    SciTech Connect

    Lee, Soojin . E-mail: leesoojin@cnu.ac.kr; Gang, Jingu; Jeon, Sun Bok; Jung, Jinyoung; Song, Si Young; Koh, Sang Seok . E-mail: sskoh@kribb.re.kr

    2007-08-31

    We examined genome-wide differences in gene expression between tumor biopsies and normal tissues in order to identify differentially regulated genes in tumors. Cancer-upregulated gene 2 (CUG2) was identified as an expressed sequence tag (EST) that exhibits significant differential expression in multiple human cancer types. CUG2 showed weak sequence homology with the down-regulator of transcription 1 (DR1) gene, a human transcription repressor. We found that EGFP-CUG2 fusion proteins were predominantly localized in the nucleus, suggesting their putative role in gene regulation. In addition, CUG2-overexpressing mouse fibroblast cells exhibited distinct cancer-specific phenotypes in vitro and developed into tumors in nude mice. Taken together, these findings suggest that CUG2 is a novel tumor-associated gene that is commonly activated in various human cancers and exhibits high transforming activities; it possibly belongs to a transcription regulator family that is involved in tumor biogenesis.

  13. Identification of genes upregulated by pinewood nematode inoculation in Japanese red pine.

    PubMed

    Shin, Hanna; Lee, Hyoshin; Woo, Kwan-Soo; Noh, Eun-Woon; Koo, Yeong-Bon; Lee, Kyung-Joon

    2009-03-01

    Pine wilt disease caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, has destroyed huge areas of pine forest in East Asia, including Japan, China and Korea. No protection against PWN has been developed, and the responses of pine trees at the molecular level are unrecorded. We isolated and analyzed upregulated or newly induced genes from PWN-inoculated Japanese red pine (Pinus densiflora Sieb. et Zucc.) by using an annealing control primer system and suppression subtractive hybridization. Significant changes occurred in the transcript abundance of genes with functions related to defense, secondary metabolism and transcription, as the disease progressed. Other gene transcripts encoding pathogenesis-related proteins, pinosylvin synthases and metallothioneins were also more abundant in PWN-inoculated trees than in non-inoculated trees. Our report provides fundamental information on the molecular mechanisms controlling the biochemical and physiological responses of Japanese red pine trees to PWN invasion. PMID:19203959

  14. Acid Ceramidase Up-regulation in Prostate Cancer: Role in Tumor Development and Implications for Therapy

    PubMed Central

    Liu, Xiang; Cheng, Joseph C.; Turner, Lorianne S.; Elojeimy, Saeed; Beckham, Thomas H.; Bielawska, Alicja; Keane, Thomas E.; Hannun, Yusuf A.; Norris, James S.

    2009-01-01

    Bioactive sphingolipids, such as ceramide, sphingosine, and sphingosine-1-phosphate are known bio-effector molecules which play important roles in various aspects of cancer biology including cell proliferation, growth arrest, apoptosis, metastasis, senescence, and inflammation. Therefore, enzymes involved in ceramide metabolism are gaining recognition as being critical regulators of cancer cell growth and/or survival. We previously observed that the ceramide metabolizing enzyme, acid ceramidase (AC), is up-regulated in tumor tissues. Studies have now concluded that this creates a dysfunctional ceramide pathway which is responsible for tumor progression and resistance to chemotherapy and radiation. This suggests that development of small molecule drugs that inhibit AC enzyme activity is a promising approach for improving standard cancer therapy and patient’s clinical outcomes. PMID:19874262

  15. ?(9)-Tetrahydrocannabinol disrupts estrogen-signaling through up-regulation of estrogen receptor ? (ER?).

    PubMed

    Takeda, Shuso; Yoshida, Kazutaka; Nishimura, Hajime; Harada, Mari; Okajima, Shunsuke; Miyoshi, Hiroko; Okamoto, Yoshiko; Amamoto, Toshiaki; Watanabe, Kazuhito; Omiecinski, Curtis J; Aramaki, Hironori

    2013-07-15

    ?(9)-Tetrahydrocannabinol (?(9)-THC) has been reported as possessing antiestrogenic activity, although the mechanisms underlying these effects are poorly delineated. In this study, we used the estrogen receptor ? (ER?)-positive human breast cancer cell line, MCF-7, as an experimental model and showed that ?(9)-THC exposures markedly suppresses 17?-estradiol (E2)- induced MCF-7 cell proliferation. We demonstrate that these effects result from ?(9)-THC's ability to inhibit E2-liganded ER? activation. Mechanistically, the data obtained from biochemical analyses revealed that (i) ?(9)-THC up-regulates ER?, a repressor of ER?, inhibiting the expression of E2/ER?-regulated genes that promote cell growth and that (ii) ?(9)-THC induction of ER? modulates E2/ER? signaling in the absence of direct interaction with the E2 ligand binding site. Therefore, the data presented support the concept that ?(9)-THC's antiestrogenic activities are mediated by the ER? disruption of E2/ER? signaling. PMID:23718638

  16. Ciona intestinalis interleukin 17-like genes expression is upregulated by LPS challenge.

    PubMed

    Vizzini, Aiti; Di Falco, Felicia; Parrinello, Daniela; Sanfratello, Maria Antonietta; Mazzarella, Claudia; Parrinello, Nicolò; Cammarata, Matteo

    2015-01-01

    In humans, IL-17 is a proinflammatory cytokine that plays a key role in the clearance of extracellular bacteria promoting cell infiltration and production of several cytokines and chemokines. Here, we report on three Ciona intestinalis IL-17 homologues (CiIL17-1, CiIL17-2, CiIL17-3). The gene organization, phylogenetic tree and modeling supported the close relationship with the mammalian IL-17A and IL-17F suggesting that the C. intestinalis IL-17 genes share a common ancestor in the chordate lineages. Real time PCR analysis showed a prompt expression induced by LPS inoculation suggesting that they are involved in the first phase of inflammatory response. In situ hybridization assays disclosed that the genes transcription was upregulated in the pharynx, the main organ of the ascidian immune system, and expressed by hemocytes (granulocytes and univacuolar refractile granulocyte) inside the pharynx vessels. PMID:25305501

  17. Causes of upregulation of glycolysis in lymphocytes upon stimulation. A comparison with other cell types.

    PubMed

    Stark, Heiko; Fichtner, Maximilian; König, Rainer; Lorkowski, Stefan; Schuster, Stefan

    2015-11-01

    In this review, we revisit the metabolic shift from respiration to glycolysis in lymphocytes upon activation, which is known as the Warburg effect in tumour cells. We compare the situation in lymphocytes with those in several other cell types, such as muscle cells, Kupffer cells, microglia cells, astrocytes, stem cells, tumour cells and various unicellular organisms (e.g. yeasts). We critically discuss and compare several explanations put forward in the literature for the observation that proliferating cells adopt this apparently less efficient pathway: hypoxia, poisoning of competitors by end products, higher ATP production rate, higher precursor supply, regulatory effects, and avoiding harmful effects (e.g. by reactive oxygen species). We conclude that in the case of lymphocytes, increased ATP production rate and precursor supply are the main advantages of upregulating glycolysis. PMID:26382968

  18. A novel transcript is up-regulated by fasting in the hypothalamus and enhances insulin signaling

    PubMed Central

    Chai, Biaoxin; Li, Ji-Yao; Fritze, Danielle; Zhang, Weizhen; Xia, Zefeng; Mulholland, Michael W

    2015-01-01

    A transcript of unknown function, regulated by fasting and feeding, was identified by microarray analysis. The transcript is up-regulated in the fasting state. An 1168 base-pair cDNA was cloned from rat hypothalamus and sequenced. This sequence is consistent with adipogenesis downregulating transcript 3 (AGD3) (also known as human OCC-1) mRNA. A protein sequence identical to AGD3 was determined by mass spectrometry. In rat brain, AGD3 mRNA is distributed in arcuate nucleus, ventromedial hypothalamus, amygdaloid nuclei, paraventricular nucleus (PVN), hippocampus, and somatic cortex. Double in situ hybridization showed that AGD3 mRNA is co-localized with pro-opiomelanocortin and neuropeptide Y in arcuate nucleus neurons. AGD3 binds with insulin receptor substrate 4 and increases insulin-stimulated phospho-AKT and regulates AMPK and mTOR downstream target S6 kinase phosphorylation. PMID:22935015

  19. Prostaglandin E2 accelerates invasion by upregulating Snail in hepatocellular carcinoma cells.

    PubMed

    Zhang, Min; Zhang, Hai; Cheng, Shanyu; Zhang, Dengcai; Xu, Yan; Bai, Xiaoming; Xia, Shukai; Zhang, Li; Ma, Juan; Du, Mingzhan; Wang, Yipin; Wang, Jie; Chen, Meng; Leng, Jing

    2014-07-01

    Our previous studies showed that prostaglandin E2 (PGE2) promotes hepatoma cell growth and migration, as well as invasion; however, the precise mechanism remains elusive. Snail and p65 protein levels were detected in human samples with hepatocellular carcinoma (HCC) by immunohistochemistry (IHC) staining. HCC cell lines (Huh-7 and Hep3B) were used for in vitro experiments. PGE2/Akt/NF-?B pathway was investigated in Huh-7 and Hep3B cells after treatment with PGE2, EP4 receptor (EP4R) agonist, Akt inhibitor, and NF-?B inhibitor, respectively, by real-time reverse transcription (RT)-PCR, Western blotting, and immunofluorescence (IF) staining. In vitro cell invasion assay was performed to evaluate the effect of PGE2 on tumor invasiveness. Knockdown of EP4R was carried out in Huh-7 cells through plasmid-based small interfering RNA (siRNA) approach to confirm the regulation of PGE2 on Snail by EP4R. Dual luciferase reporter assay was performed to assess Snail promoter activity in Huh-7 cell after treatment with EP4R agonist. We found that the protein levels of Snail were higher in HCC tissues than those in control and that PGE2 and EP4R agonist treatment significantly increased Snail expression in Huh-7 and Hep3B cells. EP4R agonist also profoundly promoted invasiveness of Huh-7 cells. Knockdown of the EP4R by siRNA completely blocked the PGE2-induced upregulation of Snail expression and reduced invasiveness of Huh-7 cells. We failed to find that EP4R-induced upregulation of Snail was reversed by inhibition of cAMP response element-binding protein (CREB), a canonical downstream target of EP4R. Alternatively, EP4R agonist treatment significantly increased the levels of phosphorylated EGFR and Akt both in Huh-7 and Hep3B cells. AG1478, an EGFR inhibitor, blocked the phosphorylation of Akt. The levels of phosphorylated I?B increased in Huh-7 cells after treatment with EP4R agonist for 30 min. The levels of phosphorylated p65 started to increase in Huh-7 cells treated with EP4R agonist for 4 h, and p65 translocated into the nucleus. In EP4R-agonist-treated Hep3B, the levels of phosphorylated p65 were also increased compared to the control group. The phosphorylation levels of p65 were significantly decreased in Huh-7 and Hep3B cells after treatment with the Akt signaling inhibitor LY294002 and EP4R agonist for 24 h. Treatment with the NF-?B inhibitor pyrrolidine dithiocarbamate (PDTC) at 10 ?M for 24 h blocked EP4R-agonist-induced Snail upregulation in Huh-7 and Hep3B cells. Furthermore, we obtained human Snail promoter sequence from TRED-Promoter Database and identified a putative binding site of NF-?B in the sequence through TFSEARCH analysis. Subsequently, we treated Huh-7 cells with EP4R agonist or EP4R agonist and PDTC (NF-?B antagonist) and found significantly increased Snail promoter activity after EP4R agonist treatment for 12 h. The increased Snail promoter activity could be partially abolished by additional PDTC treatment. In addition, p65 protein levels were found increased together with Snail in HCC tissues compared to normal liver tissues. In conclusion, PGE2 activates Akt/NF-?B signaling and then upregulates Snail via the EP4R/EGFR to promote migration and invasion in hepatoma cells. These findings may help future evaluation of novel chemo-preventive strategies for HCC. PMID:24760275

  20. Potential involvement of adipocyte insulin resistance in obesity-associated up-regulation of adipocyte lysophospholipase D/autotaxin expression

    PubMed Central

    Boucher, Jérémie; Quilliot, Didier; Pradère, Jean-Philippe; Simon, Marie-Françoise; Grès, Sandra; Guigné, Charlotte; Prévot, Danielle; Ferry, Gilles; Boutin, Jean A.; Carpéné, Christian; Valet, Philippe; Saulnier-Blache, Jean Sébastien

    2005-01-01

    Aims/hypothesis Autotaxin (ATX) is an adipocyte-secreted lysophospholipase D which expression is substantially up-regulated in obese-diabetic db/db-mice. The aim of the present study was to depict the physiopathological and cellular mechanisms involved in regulation of adipocyte-ATX expression. Methods ATX mRNAs were quantified in adipose tissue from db/db mice (obese and highly diabetic Type 2), gold-thioglucose-treated (GTG) mice (highly obese and moderately diabetic Type 2), high fat diet-fed (HFD) mice (obese and moderately diabetic Type 2), streptozotocin-treated (STREPTO) mice (thin and diabetic Type 1), and massively obese humans exhibiting glucose intolerance. Results When compared to non-obese controls, ATX expression was significantly increased in db/db mice, but not in GTG-, HFD-, or STREPTO-mice. During db/db-mice development, up-regulation of ATX occurred only 3 weeks after emergence of hyper-insulinemia, and was concomitant to emergence of hyperglycaemia. Adipocytes from db/db-mice exhibited strong impairment in insulin-stimulated glucose uptake when compared with non-obese and HFD-induced obese mice. ATX expression was up-regulated by treatment with TNF? (insulin resistance-promoting cytokine), and down-regulated by rosiglitazone treatment (insulin-sensitizing compound) in 3T3F442A adipocytes. Finally, adipose tissue-ATX expression was significantly up-regulated in patients exhibiting both insulin-resistance and impaired glucose tolerance. Conclusions/interpretation The present work demonstrates the existence of a db/db-specific up-regulation of adipocyte-ATX expression which could be related to severe Type 2 diabetes phenotype and adipocyte insulin-resistance, rather than excess adiposity per se. The present work also revealed that Type 2 diabetes in human is also associated with up-regulation of adipocyte-ATX expression. PMID:15700135

  1. Human Papillomavirus E6 Triggers Upregulation of the Antiviral and Cancer Genomic DNA Deaminase APOBEC3B

    PubMed Central

    Vieira, Valdimara C.; Leonard, Brandon; White, Elizabeth A.; Starrett, Gabriel J.; Temiz, Nuri A.; Lorenz, Laurel D.; Lee, Denis; Soares, Marcelo A.; Lambert, Paul F.; Howley, Peter M.

    2014-01-01

    ABSTRACT Several recent studies have converged upon the innate immune DNA cytosine deaminase APOBEC3B (A3B) as a significant source of genomic uracil lesions and mutagenesis in multiple human cancers, including those of the breast, head/neck, cervix, bladder, lung, ovary, and other tissues. A3B is upregulated in these tumor types relative to normal tissues, but the mechanism is unclear. Because A3B also has antiviral activity in multiple systems and is a member of the broader innate immune response, we tested the hypothesis that human papillomavirus (HPV) infection causes A3B upregulation. We found that A3B mRNA expression and enzymatic activity were upregulated following transfection of a high-risk HPV genome and that this effect was abrogated by inactivation of E6. Transduction experiments showed that the E6 oncoprotein alone was sufficient to cause A3B upregulation, and a panel of high-risk E6 proteins triggered higher A3B levels than did a panel of low-risk or noncancer E6 proteins. Knockdown experiments in HPV-positive cell lines showed that endogenous E6 is required for A3B upregulation. Analyses of publicly available head/neck cancer data further support this relationship, as A3B levels are higher in HPV-positive cancers than in HPV-negative cancers. Taken together with the established role for high-risk E6 in functional inactivation of TP53 and published positive correlations in breast cancer between A3B upregulation and genetic inactivation of TP53, our studies suggest a model in which high-risk HPV E6, possibly through functional inactivation of TP53, causes derepression of A3B gene transcription. This would lead to a mutator phenotype that explains the observed cytosine mutation biases in HPV-positive head/neck and cervical cancers. PMID:25538195

  2. Calcitriol inhibits keratinocyte proliferation by upregulating leukocyte elastase inhibitor (serpin B1).

    PubMed

    Hui, Li; Yongxia, Zheng; Zhili, Guo; Jun, Gu

    2014-05-01

    Calcitriol had been proved to be effective for treatment of psoriasis vulgaris. However, the molecular events leading to the normalization of keratinocyte differentiation had not been fully explored. The aim of the study was to evaluate the role of calcitriol and serpin B1 in human keratinocyte cell line (HaCaT) proliferation. Proteins extracted from calcitriol-treated and untreated HaCaT were separated by 2-D differential gel electrophoresis (2DE). Then, the 2DE profiles were analyzed to screen for differentially expressed proteins, which were identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry. The upregulation of serpin B1 was confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis. The effect of serpin B1 on HaCaT proliferation was analyzed by RNA interference experiments, methylthiazoletetrazolium assay and flow cytometry. Reproducible 2-DE profiles of HaCaT were established. The result that serpin B1 was upregulated in the calcitriol-treated group was confirmed by qRT-PCR and western blot analysis. Calcitriol could inhibit proliferation of HaCaT at the concentration of 10(-9) -10(-6 ) mol/L. HaCaT proliferation was promoted when serpin B1 was interfered. The inhibition effect of calcitriol was stopped after serpin B1 was interfered. Serpin B1 was overexpressed in calcitriol-treated HaCaT cells and may play an important role in inhibiting HaCaT proliferation by calcitriol. PMID:24750314

  3. Up-regulation of stromal versican expression in advanced stage serous ovarian cancer

    PubMed Central

    Ghosh, Sue; Albitar, Lina; LeBaron, Richard; Welch, William R.; Samimi, Goli; Birrer, Michael J.; Berkowitz, Ross S.; Mok, Samuel C.

    2010-01-01

    Objective The purpose of this study is to examine the role of versican (VCAN) in advanced stage serous ovarian cancer by investigating its expression, its function, and its correlation with clinical outcomes. Methods Microarray analysis was performed on RNA isolated from tumor and stromal components of advanced stage serous ovarian cancer and normal ovarian epithelial tissue to identify genes up-regulated in ovarian tumor stroma. Validation studies using immunohistochemistry and quantitative real-time PCR (Q-RT-PCR) was performed on one of the up-regulated genes, VCAN. Immunolocalization of VCAN (n=111) and CD31 (n= 56) were done on serous ovarian tumors. CD31 staining was performed to examine microvessel density (MVD). Q-RT-PCR was performed on 65 samples to evaluate the differential expression of VCAN isoforms. Cell proliferation and invasion assays were performed to examine how V1-treated ovarian cancer cell lines and an endothelial cell line would differ from controls. Univariate survival analyses were done with VCAN expression. Correlation analysis was done with CD31, platinum resistance, and clinical data. Results Validation studies using Q-RT-PCR and immunohistochemistry showed significantly higher VCAN V1 isoform expression in ovarian cancer stroma compared with normal ovarian stroma and ovarian cancer cells. Correlation studies showed stromal VCAN expression was associated with poorer overall and progression free survival, platinum resistance, and increased MVD. VCAN-treated ovarian cancer and endothelial cells showed increased invasion potential. Conclusions VCAN overexpression is associated with increased MVD and invasion potential, which may lead to poorer overall and progression free survival and platinum resistance. PMID:20619446

  4. Transient neuroprotection by SRY upregulation in dopamine cells following injury in males.

    PubMed

    Czech, Daniel P; Lee, Joohyung; Correia, Jeanne; Loke, Hannah; Möller, Eva K; Harley, Vincent R

    2014-07-01

    Emerging evidence suggest sex-specific regulation of dopamine neurons may underlie susceptibility of males to disorders such as Parkinson's disease (PD). In healthy male dopamine neurons, the Y-chromosome gene product, the sex-determining region on the Y chromosome (SRY) modulates dopamine biosynthesis and motor function. We investigated the regulation and function of SRY in a model of dopamine cell injury. Treatment with the dopaminergic toxin, 6-hydroxydopamine (6-OHDA), significantly elevated SRY mRNA expression (9-fold) in human male dopamine M17 cells. SRY up-regulation occurred via the p-quinone pathway, associated with a 3.5-fold increase in expression of GADD45?, a DNA damage inducible factor gene and known SRY regulator. In turn, a signaling cascade involving GADD45?/p38-MAPK/GATA activated the SRY promoter. Knockdown of SRY mRNA in 6-OHDA-treated M17 cells was deleterious, increasing levels of reactive oxygen species (ROS), pro-apoptotic marker PUMA mRNA, and cell injury (+25%, +32% and +34%, respectively). Conversely, ectopic over-expression of SRY in 6-OHDA-treated female SH-SY5Y cells was protective, decreasing ROS, PUMA, and cell injury (-40%, -46%, and -30%, respectively). However, the 6-OHDA-induced increase in SRY expression was diminished with higher concentrations of toxins or with chronic exposure to 6-OHDA. We conclude that SRY upregulation after dopamine cell injury is initially a protective response in males, but diminishes with gradual loss in dopamine cells. We speculate that dysregulation of SRY may contribute the susceptibility of males to PD. PMID:24708242

  5. Alteration in gene expression profile and oncogenicity of esophageal squamous cell carcinoma by RIZ1 upregulation

    PubMed Central

    Dong, Shang-Wen; Li, Dong; Xu, Cong; Sun, Pei; Wang, Yuan-Guo; Zhang, Peng

    2013-01-01

    AIM: To investigate the effect of retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) upregulation in gene expression profile and oncogenicity of human esophageal squamous cell carcinoma (ESCC) cell line TE13. METHODS: TE13 cells were transfected with pcDNA3.1(+)/RIZ1 and pcDNA3.1(+). Changes in gene expression profile were screened and the microarray results were confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Nude mice were inoculated with TE13 cells to establish ESCC xenografts. After two weeks, the inoculated mice were randomly divided into three groups. Tumors were injected with normal saline, transfection reagent pcDNA3.1(+) and transfection reagent pcDNA3.1(+)/RIZ1, respectively. Tumor development was quantified, and changes in gene expression of RIZ1 transfected tumors were detected by RT-PCR and Western blotting. RESULTS: DNA microarray data showed that RIZ1 transfection induced widespread changes in gene expression profile of cell line TE13, with 960 genes upregulated and 1163 downregulated. Treatment of tumor xenografts with RIZ1 recombinant plasmid significantly inhibited tumor growth, decreased tumor size, and increased expression of RIZ1 mRNA compared to control groups. The changes in gene expression profile were also observed in vivo after RIZ1 transfection. Most of the differentially expressed genes were associated with cell development, supervision of viral replication, lymphocyte costimulatory and immune system development in esophageal cells. RIZ1 gene may be involved in multiple cancer pathways, such as cytokine receptor interaction and transforming growth factor beta signaling. CONCLUSION: The development and progression of esophageal cancer are related to the inactivation of RIZ1. Virus infection may also be an important factor. PMID:24115813

  6. Dihydroartemisinin induces apoptosis of cervical cancer cells via upregulation of RKIP and downregulation of bcl-2

    PubMed Central

    Hu, Chun-jie; Zhou, Lei; Cai, Yan

    2014-01-01

    Treatment of recurrent and metastatic cervical cancer remains a challenge, especially in developing countries, which lack efficient screening programs. In recent years, artemisinin and its derivatives, such as dihydroartemisinin (DHA), which were traditionally used as anti-malarial agent, have been shown to inhibit tumor growth with low toxicity to normal cells. In this study, we investigated mechanisms underlying the anti-tumor effect of DHA in cervical cancer. We evaluated the role of DHA on the expression of bcl-2 and Raf kinase inhibitor protein (RKIP), which is a suppressor of metastasis. The MTT assay was used to compare the proliferation of untreated and DHA-treated Hela and Caski cervical cancer cells. Flow cytometry was used to determine the percentage of cells at each stage of the cell cycle in untreated and DHA-treated cells. We used RT-PCR and western blots to determine the expression of bcl-2 and RKIP mRNA and proteins. We evaluated the effect of DHA treatment in nude mice bearing Hela or Caski tumors. DHA-treated cells showed a time- and dose-dependent inhibition of proliferation and a significant increase in apoptosis. The expression of RKIP was significantly upregulated and the expression of bcl-2 was significantly downregulated in DHA-treated cells compared with control cells. DHA treatment caused (1) a significant inhibition of tumor growth and (2) a significant increase in the apoptotic index in nude mice bearing Hela or Caski tumors. Our data suggest that DHA inhibits cervical cancer growth via upregulation of RKIP and downregulation of bcl-2. PMID:24335512

  7. Quantum dot-induced cell death involves Fas upregulation and lipid peroxidation in human neuroblastoma cells

    PubMed Central

    Choi, Angela O; Cho, Sung Ju; Desbarats, Julie; Lovri?, Jasmina; Maysinger, Dusica

    2007-01-01

    Background Neuroblastoma, a frequently occurring solid tumour in children, remains a therapeutic challenge as existing imaging tools are inadequate for proper and accurate diagnosis, resulting in treatment failures. Nanoparticles have recently been introduced to the field of cancer research and promise remarkable improvements in diagnostics, targeting and drug delivery. Among these nanoparticles, quantum dots (QDs) are highly appealing due to their manipulatable surfaces, yielding multifunctional QDs applicable in different biological models. The biocompatibility of these QDs, however, remains questionable. Results We show here that QD surface modifications with N-acetylcysteine (NAC) alter QD physical and biological properties. In human neuroblastoma (SH-SY5Y) cells, NAC modified QDs were internalized to a lesser extent and were less cytotoxic than unmodified QDs. Cytotoxicity was correlated with Fas upregulation on the surface of treated cells. Alongside the increased expression of Fas, QD treated cells had increased membrane lipid peroxidation, as measured by the fluorescent BODIPY-C11 dye. Moreover, peroxidized lipids were detected at the mitochondrial level, contributing to the impairment of mitochondrial functions as shown by the MTT reduction assay and imaged with confocal microscopy using the fluorescent JC-1 dye. Conclusion QD core and surface compositions, as well as QD stability, all influence nanoparticle internalization and the consequent cytotoxicity. Cadmium telluride QD-induced toxicity involves the upregulation of the Fas receptor and lipid peroxidation, leading to impaired neuroblastoma cell functions. Further improvements of nanoparticles and our understanding of the underlying mechanisms of QD-toxicity are critical for the development of new nanotherapeutics or diagnostics in nano-oncology. PMID:17295922

  8. Calcyon Up-regulation in Adolescence Impairs Response Inhibition and Working Memory in Adulthood

    PubMed Central

    Vazdarjanova, Almira; Bunting, Kristopher; Muthusamy, Nagendran; Bergson, Clare

    2014-01-01

    Calcyon regulates activity dependent internalization of AMPA glutamate receptors and long term depression of excitatory synapses. Elevated levels of calcyon are consistently observed in brains from schizophrenic patients, and the calcyon gene is associated with attention deficit hyperactivity disorder. Executive function deficits are common to both disorders, and at least for schizophrenia, the etiology appears to involve both heritable and neurodevelopmental factors. Here, we show with calcyon overexpressing CalOE transgenic mice that lifelong calcyon upregulation impairs executive functions including response inhibition and working memory, without producing learning and memory deficits in general. As response inhibition and working memory, as well as the underlying neural circuitry continue to mature into early adulthood, we functionally silenced the transgene during postnatal days 28–49, a period corresponding to adolescence. Remarkably, the response inhibition and working memory deficits including perseverative behavior were absent in adult CalOE mice with the transgene silenced in adolescence. Suppressing the calcyon transgene in adulthood only partially rescued the deficits, suggesting calcyon upregulation in adolescence irreversibly alters development of neural circuits supporting mature response inhibition and working memory. Brain regional immunoblots revealed a prominent down-regulation of AMPA GluR1 subunits in hippocampus, and GluR2/3 subunits in hippocampus and prefrontal cortex of the CalOE mice. Silencing the transgene in adolescence prevented the decrease in hippocampal GluR1, further implicating altered frontohippocampal connectivity in the executive function deficits observed in the CalOE mice. Treatments that mitigate the effects of high levels of calcyon during adolescence could preempt adult deficits in executive functions in individuals at-risk for serious mental illness. PMID:21403673

  9. RAGE signaling deficiency in rhabdomyosarcoma cells causes upregulation of PAX7 and uncontrolled proliferation.

    PubMed

    Riuzzi, Francesca; Sorci, Guglielmo; Sagheddu, Roberta; Sidoni, Angelo; Alaggio, Rita; Ninfo, Vito; Donato, Rosario

    2014-04-15

    Embryonal rhabdomyosarcomas (ERMSs) show elevated levels of PAX7, a transcription factor that marks quiescent adult muscle stem (satellite) cells and is important for proliferation and survival of activated satellite cells and whose timely repression is required for myogenic differentiation. However, the mechanism of PAX7 accumulation in ERMSs and whether high PAX7 causes uncontrolled proliferation in ERMS remains to be elucidated. The receptor for advanced glycation end-products (RAGE, encoded by AGER) transduces a myogenic and anti-proliferative signal in myoblasts, and stable transfection of the ERMS cell line TE671, which does not express RAGE, with AGER results in reduced proliferation and formation of tumor masses in vivo, and enhanced apoptosis and myogenic differentiation. Herein, we show that RAGE expression is low or absent in human ERMSs. We also show that in ERMS cells (1) PAX7 accumulates owing to absent or low RAGE signaling; (2) elevated PAX7 levels reduce RAGE expression and levels of MyoD and myogenin, muscle-specific transcription factors required for myoblast proliferation arrest and differentiation, respectively; (3) PAX7 supports myoblast proliferation by reducing the levels of MyoD, primarily by promoting its degradation; and (4), when ectopically expressed in ERMS cells, that RAGE upregulates myogenin which upregulates MyoD and downregulates PAX7, with consequent inhibition of proliferation and stimulation of differentiation. Thus, failure to express RAGE and, hence, MyoD and myogenin above a critical level in ERMS cells might result in deregulated PAX7 expression leading to uncontrolled proliferation and, potentially, to rhabdomyosarcomagenesis. PMID:24554430

  10. 4-Hydroxynonenal induces Nrf2-mediated UCP3 upregulation in mouse cardiomyocytes.

    PubMed

    López-Bernardo, Elia; Anedda, Andrea; Sánchez-Pérez, Patricia; Acosta-Iborra, Bárbara; Cadenas, Susana

    2015-11-01

    4-Hydroxy-2-nonenal (HNE) is a highly cytotoxic product of lipid peroxidation. Nevertheless, at low concentrations, it is able to mediate cell signaling and to activate protective pathways, including that of the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2). In addition, HNE activates uncoupling proteins (UCPs), mitochondrial inner membrane proteins that mediate uncoupling of oxidative phosphorylation and have been proposed to protect against oxidative stress. It is not known, however, whether HNE might induce UCP expression via Nrf2 to cause mitochondrial uncoupling. We investigated the effects of HNE on UCP3 expression in mouse cardiomyocytes and the involvement of Nrf2. HNE induced the nuclear accumulation of Nrf2 and enhanced UCP3 expression, effects prevented by the antioxidant N-acetylcysteine. ChIP assays indicated that Nrf2 bound to the Ucp3 promoter after HNE treatment, increasing its expression. Cardiomyocytes treated with Nrf2- or UCP3-specific siRNA were less tolerant to HNE as reflected by increased cell death, and Nrf2 siRNA prevented HNE-induced UCP3 upregulation. The treatment with HNE greatly altered cardiomyocyte bioenergetics, increasing the proton leak across the inner mitochondrial membrane and severely decreasing the maximal respiratory capacity and the respiratory reserve capacity. These findings confirm that low HNE doses activate Nrf2 in cardiomyocytes and provide the first evidence of Nrf2 binding to the Ucp3 promoter in response to HNE, leading to increased protein expression. These results suggest that the upregulation of UCP3 mediated by Nrf2 in response to HNE might be important in the protection of the heart under conditions of oxidative stress such as ischemia-reperfusion. PMID:25843654

  11. Fasting Enhances TRAIL-Mediated Liver Natural Killer Cell Activity via HSP70 Upregulation

    PubMed Central

    Dang, Vu T. A.; Tanabe, Kazuaki; Tanaka, Yuka; Tokumoto, Noriaki; Misumi, Toshihiro; Saeki, Yoshihiro; Fujikuni, Nobuaki; Ohdan, Hideki

    2014-01-01

    Acute starvation, which is frequently observed in clinical practice, sometimes augments the cytolytic activity of natural killer cells against neoplastic cells. In this study, we investigated the molecular mechanisms underlying the enhancement of natural killer cell function by fasting in mice. The total number of liver resident natural killer cells in a unit weight of liver tissue obtained from C57BL/6J mice did not change after a 3-day fast, while the proportions of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)+ and CD69+ natural killer cells were significantly elevated (n?=?7, p <0.01), as determined by flow cytometric analysis. Furthermore, we found that TRAIL? natural killer cells that were adoptively transferred into Rag-2?/? ? chain?/? mice could convert into TRAIL+ natural killer cells in fasted mice at a higher proportion than in fed mice. Liver natural killer cells also showed high TRAIL-mediated antitumor function in response to 3-day fasting. Since these fasted mice highly expressed heat shock protein 70 (n?=?7, p <0.05) in liver tissues, as determined by western blot, the role of this protein in natural killer cell activation was investigated. Treatment of liver lymphocytes with 50 µg/mL of recombinant heat shock protein 70 led to the upregulation of both TRAIL and CD69 in liver natural killer cells (n?=?6, p <0.05). In addition, HSP70 neutralization by intraperitoneally injecting an anti- heat shock protein 70 monoclonal antibody into mice prior to fasting led to the downregulation of TRAIL expression (n?=?6, p <0.05). These findings indicate that acute fasting enhances TRAIL-mediated liver natural killer cell activity against neoplastic cells through upregulation of heat shock protein 70. PMID:25356750

  12. RFPL3 and CBP synergistically upregulate hTERT activity and promote lung cancer growth.

    PubMed

    Qin, Yu; Chen, Wangbing; Xiao, Yao; Yu, Wendan; Cai, Xin; Dai, Meng; Xu, Tingting; Huang, Wenlin; Guo, Wei; Deng, Wuguo; Wu, Taihua

    2015-09-29

    hTERT is the key component of telomerase and its overactivation contributes to maintaining telomere length and cell immortalization. Previously, we identified RFPL3 as a new transcription activator of hTERT in lung cancers. However, the exact mechanism of RFPL3 in mediating hTERT activation and its associated signal regulatory network remain unclear. In this study, we found that RFPL3 colocalized and interacted directly with CBP in the nucleus of lung cancer cells. Immunohistochemical analysis of tissue microarrays of lung cancers revealed the simultaneous overexpression of both RFPL3 and CBP predicted relatively poor prognosis. Furthermore, we confirmed their synergistic stimulation on hTERT expression and tumor cell growth. The binding of RFPL3 to hTERT promoter was reduced markedly when CBP was knocked down by its specific siRNA or suppressed by its inhibitor in lung cancer cells with stable overexpression of RFPL3. When one of the two proteins RFPL3 and CBP was upregulated or downregulated, whereas the another remains unchanged, hTERT expression and telomerase activity were activated or repressed accordingly. In the meantime, the growth of lung cancer cells was also promoted or attenuated accordingly. Furthermore, we also found that RFPL3 coordinated with CBP to upregulate hTERT through the CBP-induced acetylation of RFPL3 protein and their co-anchoring at hTERT promoter region. Collectively, our results reveal a new mechanism of hTERT regulation in lung cancer cells and suggest the RFPL3/CBP/hTERT signaling pathway may be a new targets for lung cancer treatment. PMID:26318425

  13. To Investigate the Necessity of STRA6 Upregulation in T Cells during T Cell Immune Responses

    PubMed Central

    Charpentier, Tania; Lamarre, Alain; Zhong, Ming; Sun, Hui; Mao, Jianning; Qi, Shijie; Luo, Hongyu; Wu, Jiangping

    2013-01-01

    Our earlier study revealed that STRA6 (stimulated by retinoic acid gene 6) was up-regulated within 3 h of TCR stimulation. STRA6 is the high-affinity receptor for plasma retinol-binding protein (RBP) and mediates cellular vitamin A uptake. We generated STRA6 knockout (KO) mice to assess whether such up-regulation was critical for T-cell activation, differentiation and function. STRA6 KO mice under vitamin A sufficient conditions were fertile without apparent anomalies upon visual inspection. The size, cellularity and lymphocyte subpopulations of STRA6 KO thymus and spleen were comparable to those of their wild type (WT) controls. KO and WT T cells were similar in terms of TCR-stimulated proliferation in vitro and homeostatic expansion in vivo. Naive KO CD4 cells differentiated in vitro into Th1, Th2, Th17 as well as regulatory T cells in an analogous manner as their WT counterparts. In vivo experiments revealed that anti-viral immune responses to lymphocytic choriomeningitis virus in KO mice were comparable to those of WT controls. We also demonstrated that STRA6 KO and WT mice had similar glucose tolerance. Total vitamin A levels are dramatically lower in the eyes of KO mice as compared to those of WT mice, but the levels in other organs were not significantly affected after STRA6 deletion under vitamin A sufficient conditions, indicating that the eye is the mouse organ most sensitive to the loss of STRA6. Our results demonstrate that 1) in vitamin A sufficiency, the deletion of STRA6 in T cells does no affect the T-cell immune responses so-far tested, including those depend on STAT5 signaling; 2) STRA6-independent vitamin A uptake compensated the lack of STRA6 in lymphoid organs under vitamin A sufficient conditions in mice; 3) STRA6 is critical for vitamin A uptake in the eyes even in vitamin A sufficiency. PMID:24391722

  14. IL-6 up-regulates the expression of rat LH receptors during granulosa cell differentiation.

    PubMed

    Imai, Fumiharu; Kishi, Hiroshi; Nakao, Kohshiro; Nishimura, Toshio; Minegishi, Takashi

    2014-04-01

    IL-6 is produced in granulosa cells under normal physiological conditions, including during ovulation. However, the roles of IL-6 in ovarian function, including regulation of LH receptor (LHR) expression in granulosa cells, have not been explored in detail. The aim of this study was to identify the mechanism underlying the effect of IL-6 on LHR expression in the granulosa cells of female Wistar rats. Our results indicated that IL-6 clearly enhanced the FSH-induced LHR mRNA expression in a dose-dependent manner and did not stimulate cAMP accumulation by itself. The membrane protein level of LHR, assessed by a binding assay, was increased by FSH and was further enhanced by association with IL-6. Results of the luciferase assay, using promoter constructs of LHR 281 bp upstream of the translational start site, revealed that IL-6 increased the promoter activity induced by FSH, but this effect was not observed with treatment by IL-6 alone. This ability of IL-6 to enhance FSH-induced LHR mRNA expression was blocked by the Janus tyrosine kinase (JAK) pathway inhibitor, but not by the ERK1/2 inhibitor. Thus, we speculated that this IL-6 activity might be mediated by the JAK/signal transducer and activator of transcription pathway. In addition, IL-6 augmented FSH-induced IL-6 receptor ? mRNA expression and FSH elevated IL-6 production in granulosa cells, which indicates that IL-6 may positively regulate paracrine and autocrine actions in granulosa cells. These results suggest that IL-6 up-regulates FSH-induced LHR production by increasing mRNA transcription, and JAK/signal transducer and activator of transcription 3 signaling is required for up-regulation by IL-6 in granulosa cells. PMID:24467743

  15. Upregulation of Nox4 by hypertrophic stimuli promotes apoptosis and mitochondrial dysfunction in cardiac myocytes

    PubMed Central

    Ago, Tetsuro; Kuroda, Junya; Pain, Jayashree; Fu, Cexiong; Li, Hong; Sadoshima, Junichi

    2010-01-01

    Rationale NADPH oxidases are a major source of superoxide (O2?) in the cardiovascular system. The function of Nox4, a member of the Nox family of NADPH oxidases, in the heart is poorly understood. Objective The goal of this study was to elucidate the role of Nox4 in mediating oxidative stress and growth/death in the heart. Methods and Results Expression of Nox4 in the heart was increased in response to hypertrophic stimuli and aging. Neither transgenic mice with cardiac specific overexpression of Nox4 (Tg-Nox4) nor those with catalytically inactive Nox4 (Tg-Nox4-P437H) showed an obvious baseline cardiac phenotype at young ages. Tg-Nox4 gradually displayed decreased left ventricular (LV) function with enhanced O2? production in the heart, which was accompanied by increased apoptosis and fibrosis at 13–14 months of age. On the other hand, the level of oxidative stress was attenuated in Tg-Nox4-P437H. Although the size of cardiac myocytes was significantly greater in Tg-Nox4 than in NTg, the LV weight/tibial length was not significantly altered in Tg-Nox4 mice. Overexpression of Nox4 in cultured cardiac myocytes induced apoptotic cell death but not hypertrophy. Nox4 is primarily localized in mitochondria and upregulation of Nox4 enhanced both rotenone- and diphenyleneiodonium-sensitive O2? production in mitochondria. Cysteine residues in mitochondrial proteins, including aconitase and NADH dehydrogenases, were oxidized and their activities decreased in Tg-Nox4. Conclusions Upregulation of Nox4 by hypertrophic stimuli and aging induces oxidative stress, apoptosis and LV dysfunction, in part due to mitochondrial insufficiency caused by increased O2? production and consequent cysteine oxidation in mitochondrial proteins. PMID:20185797

  16. Upregulation of human heme oxygenase gene expression by Ets-family proteins.

    PubMed

    Deramaudt, B M; Remy, P; Abraham, N G

    1999-03-01

    Overexpression of human heme oxygenase-1 has been shown to have the potential to promote EC proliferation and angiogenesis. Since Ets-family proteins have been shown to play an important role in angiogenesis, we investigated the presence of ETS binding sites (EBS), GGAA/T, and ETS protein contributing to human HO-1 gene expression. Several chloramphenicol acetyltransferase constructs were examined in order to analyze the effect of ETS family proteins on the transduction of HO-1 in Xenopus oocytes and in microvessel endothelial cells. Heme oxygenase promoter activity was up-regulated by FLI-1ERGETS-1 protein(s). Chloramphenicol acetyltransferase (CAT) assays demonstrated that the promoter region (-1500 to +19) contains positive and negative control elements and that all three members of the ETS protein family were responsible for the up-regulation of HHO-1. Electrophoretic mobility shift assays (EMSA), performed with nuclear extracts from endothelial cells overexpressing HHO-1 gene, and specific HHO-1 oligonucleotides probes containing putative EBS resulted in a specific and marked bandshift. Synergistic binding was observed in EMSA between AP-1 on the one hand, FLI-1, ERG, and ETS-1 protein on the other. Moreover, 5'-deletion analysis demonstrated the existence of a negative control element of HHO-1 expression located between positions -1500 and -120 on the HHO-1 promoter. The presence of regulatory sequences for transcription factors such as ETS-1, FLI-1, or ERG, whose activity is associated with cell proliferation, endothelial cell differentiation, and matrix metalloproteinase transduction, may be an indication of the important role that HO-1 may play in coronary collateral circulation, tumor growth, angiogenesis, and hemoglobin-induced endothelial cell injuries. PMID:10022513

  17. Haplodeficiency of Klotho Gene Causes Arterial Stiffening via Upregulation of Scleraxis Expression and Induction of Autophagy.

    PubMed

    Chen, Kai; Zhou, Xiaoli; Sun, Zhongjie

    2015-11-01

    The prevalence of arterial stiffness increases with age, whereas the level of the aging-suppressor protein klotho decreases with age. The objective of this study is to assess whether haplodeficiency of klotho gene causes arterial stiffness and to investigate the underlying mechanism. Pulse wave velocity, a direct measure of arterial stiffness, was increased significantly in klotho heterozygous (klotho(+/-)) mice versus their age-matched wild-type (WT) littermates, suggesting that haplodeficiency of klotho causes arterial stiffening. Notably, plasma aldosterone levels were elevated significantly in klotho(+/-) mice. Treatment with eplerenone (6 mg/kg per day IP), an aldosterone receptor blocker, abolished klotho deficiency-induced arterial stiffening in klotho(+/-) mice. Klotho deficiency was associated with increased collagen and decreased elastin contents in the media of aortas. In addition, arterial matrix metalloproteinase-2, matrix metalloproteinase-9, and transforming growth factor-?1 expression and myofibroblast differentiation were increased in klotho(+/-) mice. These klotho deficiency-related changes can be blocked by eplerenone. Protein expression of scleraxis, a transcription factor for collagen synthesis, and LC3-II/LC3-I, an index of autophagy, were upregulated in aortas of klotho(+/-) mice, which can be abolished by eplerenone. In cultured mouse aortic smooth muscle cells, aldosterone increased collagen-1 expression that can be completely eliminated by small interfering RNA knockdown of scleraxis. Interestingly, aldosterone decreased elastin levels in smooth muscle cells, which can be abolished by small interfering RNA knockdown of Beclin-1, an autophagy-related gene. In conclusion, this study demonstrated for the first time that klotho deficiency-induced arterial stiffening may involve aldosterone-mediated upregulation of scleraxis and induction of autophagy, which led to increased collagen-1 expression and decreased elastin levels, respectively. PMID:26324504

  18. Fasting enhances TRAIL-mediated liver natural killer cell activity via HSP70 upregulation.

    PubMed

    Dang, Vu T A; Tanabe, Kazuaki; Tanaka, Yuka; Tokumoto, Noriaki; Misumi, Toshihiro; Saeki, Yoshihiro; Fujikuni, Nobuaki; Ohdan, Hideki

    2014-01-01

    Acute starvation, which is frequently observed in clinical practice, sometimes augments the cytolytic activity of natural killer cells against neoplastic cells. In this study, we investigated the molecular mechanisms underlying the enhancement of natural killer cell function by fasting in mice. The total number of liver resident natural killer cells in a unit weight of liver tissue obtained from C57BL/6J mice did not change after a 3-day fast, while the proportions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)+ and CD69+ natural killer cells were significantly elevated (n?=?7, p <0.01), as determined by flow cytometric analysis. Furthermore, we found that TRAIL- natural killer cells that were adoptively transferred into Rag-2-/- ? chain-/- mice could convert into TRAIL+ natural killer cells in fasted mice at a higher proportion than in fed mice. Liver natural killer cells also showed high TRAIL-mediated antitumor function in response to 3-day fasting. Since these fasted mice highly expressed heat shock protein 70 (n?=?7, p <0.05) in liver tissues, as determined by western blot, the role of this protein in natural killer cell activation was investigated. Treatment of liver lymphocytes with 50 µg/mL of recombinant heat shock protein 70 led to the upregulation of both TRAIL and CD69 in liver natural killer cells (n?=?6, p <0.05). In addition, HSP70 neutralization by intraperitoneally injecting an anti- heat shock protein 70 monoclonal antibody into mice prior to fasting led to the downregulation of TRAIL expression (n?=?6, p <0.05). These findings indicate that acute fasting enhances TRAIL-mediated liver natural killer cell activity against neoplastic cells through upregulation of heat shock protein 70. PMID:25356750

  19. GABAergic mRNA expression is upregulated in the prefrontal cortex of rats sensitized to methamphetamine.

    PubMed

    Wearne, Travis A; Parker, Lindsay M; Franklin, Jane L; Goodchild, Ann K; Cornish, Jennifer L

    2016-01-15

    Inhibitory gamma-aminobutyric acid (GABA)-mediated neurotransmission plays an important role in the regulation of the prefrontal cortex (PFC), with increasing evidence suggesting that dysfunctional GABAergic processing of the PFC may underlie certain deficits reported across psychotic disorders. Methamphetamine (METH) is a psychostimulant that induces chronic psychosis in a subset of users, with repeat administration producing a progressively increased vulnerability to psychotic relapse following subsequent drug administration (sensitization). The aim here was to investigate changes to GABAergic mRNA expression in the PFC of rats sensitized to METH using quantitative polymerase chain reaction (qPCR). Male Sprague-Dawley rats (n=12) underwent repeated methamphetamine (intraperitoneal (i.p.) or saline injections for 7 days. Following 14 days of withdrawal, rats were challenged with acute methamphetamine (1mg/kg i.p.) and RNA was isolated from the PFC to compare the relative mRNA expression of a range of GABA enzymes, transporters and receptors subunits. METH challenge resulted in a significant sensitized behavioral (locomotor) response in METH pre-treated animals compared with saline pre-treated controls. The mRNAs of transporters (GAT1 and GAT3), ionotropic GABAA receptor subunits (?3 and ?1), together with the metabotropic GABAB1 receptor, were upregulated in the PFC of sensitized rats compared with saline controls. These findings indicate that GABAergic mRNA expression is significantly altered at the pre and postsynaptic level following sensitization to METH, with sensitization resulting in the transcriptional upregulation of several inhibitory genes. These changes likely have significant consequences on GABA-mediated neurotransmission in the PFC and may underlie certain symptoms conserved across psychotic disorders, such as executive dysfunction. PMID:26475507

  20. AEBP1 upregulation confers acquired resistance to BRAF (V600E) inhibition in melanoma

    PubMed Central

    Hu, W; Jin, L; Jiang, C C; Long, G V; Scolyer, R A; Wu, Q; Zhang, X D; Mei, Y; Wu, M

    2013-01-01

    An activating BRAF (V600E) kinase mutation occurs in approximately half of melanomas. Recent clinical studies have demonstrated that vemurafenib (PLX4032) and dabrafenib, potent and selective inhibitors of mutant v-raf murine sarcoma viral oncogene homolog B1 (BRAF), exhibit remarkable activities in patients with V600 BRAF mutant melanomas. However, acquired drug resistance invariably develops after the initial treatment. Identification of acquired resistance mechanisms may inform the development of new therapies that elicit long-term responses of melanomas to BRAF inhibitors. Here we report that increased expression of AEBP1 (adipocyte enhancer-binding protein 1) confers acquired resistance to BRAF inhibition in melanoma. AEBP1 is shown to be highly upregulated in PLX4032-resistant melanoma cells because of the hyperactivation of the PI3K/Akt-cAMP response element-binding protein (CREB) signaling pathway. This upregulates AEBP1 expression and thus leads to the activation of NF-?B via accelerating I?Ba degradation. In addition, inhibition of the PI3K/Akt-CREB-AEBP1-NF-?B pathway greatly reverses the PLX4032-resistant phenotype of melanoma cells. Furthermore, increased expression of AEBP1 is validated in post-treatment tumors in patients with acquired resistance to BRAF inhibitor. Therefore, these results reveal a novel PI3K/Akt-CREB-AEBP1-NF-?B pathway whose activation contributes to acquired resistance to BRAF inhibition, and suggest that this pathway, particularly AEBP1, may represent a novel therapeutic target for treating BRAF inhibitor-resistant melanoma. PMID:24201813

  1. Gi-Biased ?2AR Signaling Links GRK2 Upregulation to Heart Failure

    PubMed Central

    Zhu, Weizhong; Petrashevskaya, Natalia; Ren, Shuxun; Zhao, Aizhi; Chakir, Khalid; Gao, Erhe; Chuprun, J. Kurt; Wang, Yibin; Tala, Mark; Dorn, Gerald W.; Lakatta, Edward G.; Koch, Walter J; Feldman, Arthur M.; Xiao, Rui-Ping

    2012-01-01

    Rationale Phosphorylation of ?2-adrenergic receptor (?2AR) by a family of serine/threonine kinases known as G protein-coupled receptor kinase (GRK) and protein kinase A (PKA) is a critical determinant of cardiac function. Upregulation of G protein-coupled receptor kinase 2 (GRK2) is a well-established causal factor of heart failure, but the underlying mechanism is poorly understood. Objective We seek to determine the relative contribution of PKA- and GRK-mediated phosphorylation of ?2AR to the receptor coupling to Gi signaling that attenuates cardiac reserve and contributes to the pathogenesis of heart failure in response to pressure overload. Methods and Results Overexpression of GRK2 led to a Gi-dependent decrease of contractile response to ?AR stimulation in cultured mouse cardiomyocytes and in vivo. Importantly, cardiac-specific transgenic overexpression of a mutant ?2AR lacking PKA phosphorylation sites (PKA- TG), but not the wild type ?2AR (WT TG) or a mutant ?2AR lacking GRK sites (GRK- TG), led to exaggerated cardiac response to pressure overload, as manifested by markedly exacerbated cardiac maladaptive remodeling and failure, and early mortality. Furthermore, inhibition of Gi signaling with pertussis toxin restores cardiac function in heart failure associated with increased ?2AR to Gi coupling induced by removing PKA phosphorylation of the receptor and in GRK2 transgenic mice, indicating that enhanced phosphorylation of ?2AR by GRK and resultant increase in Gi-biased ?2AR signaling play an important role in the development of heart failure. Conclusions Our data show that enhanced ?2AR phosphorylation by GRK, in addition to PKA, leads the receptor to Gi-biased signaling which, in turn, contributes to the pathogenesis of heart failure, marking Gi-biased ?2AR signaling as a primary event linking upregulation of GRK to cardiac maladaptive remodeling, failure and cardiodepression. PMID:22179058

  2. NOD1 receptor is up-regulated in diabetic human and murine myocardium.

    PubMed

    Prieto, Patricia; Vallejo-Cremades, María Teresa; Benito, Gemma; González-Peramato, Pilar; Francés, Daniel; Agra, Noelia; Terrón, Verónica; Gónzalez-Ramos, Silvia; Delgado, Carmen; Ruiz-Gayo, Mariano; Pacheco, Ivette; Velasco-Martín, Juan P; Regadera, Javier; Martín-Sanz, Paloma; López-Collazo, Eduardo; Boscá, Lisardo; Fernández-Velasco, María

    2014-12-01

    Type 2 diabetes has a complex pathology that involves a chronic inflammatory state. Emerging evidence suggests a link between the innate immune system receptor NOD1 (nucleotide-binding and oligomerization domain 1) and the pathogenesis of diabetes, in monocytes and hepatic and adipose tissues. The aim of the present study was to assess the role of NOD1 in the progression of diabetic cardiomyopathy. We have measured NOD1 protein in cardiac tissue from Type 2 diabetic (db) mice. Heart and isolated cardiomyocytes from db mice revealed a significant increase in NOD1, together with an up-regulation of nuclear factor ?B (NF-?B) and increased apoptosis. Heart tissue also exhibited an enhanced expression of pro-inflammatory cytokines. Selective NOD1 activation with C12-?-D-glutamyl-m-diaminopimelic acid (iEDAP) resulted in an increased NF-?B activation and apoptosis, demonstrating the involvement of NOD1 both in wild-type and db mice. Moreover, HL-1 cardiomyocytes exposed to elevated concentrations of glucose plus palmitate displayed an enhanced NF-?B activity and apoptotic profile, which was prevented by silencing of NOD1 expression. To address this issue in human pathology, NOD1 expression was evaluated in myocardium obtained from patients with Type 2 diabetes (T2DMH) and from normoglycaemic individuals without cardiovascular histories (NH). We have found that NOD1 was expressed in both NH and T2DMH; however, NOD1 expression was significantly pronounced in T2DMH. Furthermore, both the pro-inflammatory cytokine tumour necrosis factor ? (TNF-?) and the apoptosis mediator caspase-3 were up-regulated in T2DMH samples. Taken together, our results define an active role for NOD1 in the heightened inflammatory environment associated with both experimental and human diabetic cardiac disease. PMID:24934088

  3. Interleukin-6 upregulates paraoxonase 1 gene expression via an AKT/NF-?B-dependent pathway

    SciTech Connect

    Cheng, Chi-Chih; Hsueh, Chi-Mei; Chen, Chiu-Yuan; Chen, Tzu-Hsiu; Hsu, Shih-Lan; Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, Taiwan

    2013-07-19

    Highlights: •IL-6 could induce PON1 gene expression. •IL-6 increased NF-?B protein expression and NF-?B-p50 and -p65 subunits nuclear translocation. •IL-6-induced PON1 up-regulation was through an AKT/NF-?B pathway. -- Abstract: The aim of this study is to investigate the relationship between paraoxonase 1 (PON1) and atherosclerosis-related inflammation. In this study, human hepatoma HepG2 cell line was used as a hepatocyte model to examine the effects of the pro-inflammatory cytokines on PON1 expression. The results showed that IL-6, but not TNF-? and IL-1?, significantly increased both the function and protein level of PON1; data from real-time RT-PCR analysis revealed that the IL-6-induced PON1 expression occurred at the transcriptional level. Increase of I?B kinase activity and I?B phosphorylation, and reduction of I?B protein level were also observed in IL-6-treated HepG2 cells compared with untreated culture. This event was accompanied by increase of NF-?B-p50 and -p65 nuclear translocation. Moreover, treatment with IL-6 augmented the DNA binding activity of NF-?B. Furthermore, pharmacological inhibition of NF-?B activation by PDTC and BAY 11-7082, markedly suppressed the IL-6-mediated PON1 expression. In addition, IL-6 increased the levels of phosphorylated protein kinase B (PKB, AKT). An AKT inhibitor LY294002 effectively suppressed IKK/I?B/NF-?B signaling and PON1 gene expression induced by IL-6. Our findings demonstrate that IL-6 upregulates PON1 gene expression through an AKT/NF-?B signaling axis in human hepatocyte-derived HepG2 cell line.

  4. Expanding the use of monoclonal antibody therapy of cancer by using ionising radiation to upregulate antibody targets

    PubMed Central

    Wattenberg, M M; Kwilas, A R; Gameiro, S R; Dicker, A P; Hodge, J W

    2014-01-01

    Background: Monoclonal antibody (mAb) therapy for the treatment of solid and haematologic malignancies has shown poor response rates as a monotherapy. Furthermore, its use is limited to tumours expressing certain molecular targets. It has been shown that single-dose radiation can induce immunogenic modulation that is characterised by cell-surface phenotypic changes leading to augmented tumour cell/cytotoxic T-cell interaction. Methods: We examined radiation's ability to upregulate mAb therapy targets. We also used radiation to sensitise tumour cells to antibody-dependent cell-mediated cytotoxicity (ADCC). Results: Radiation significantly increased cell-surface and total protein expression of mAb targets HER2, EGFR, and CD20. Focusing on HER2, targeted by trastuzumab, we observed significant upregulation of HER2 following radiation of 3 out of 3 breast cancer cell lines, one of which was triple negative, as well as in residential stem-cell populations. HER2 upregulation was sustained up to 96?h following radiation exposure and was largely dependent on intracellular reactive oxygen species. Improved ADCC and sensitisation to the antiproliferative effects of trastuzumab demonstrated the functional significance of radiation-induced HER2 upregulation. Conclusions: We show that single-dose radiation enhances mAb therapy. These findings highlight a mechanism for combining radiation with immunotherapy and expand the patient population that can be treated with targeted therapy. PMID:24556625

  5. Cotton Benzoquinon Reductase: Up-Regulation During Early Fiber Development and Heterologous Expresson and Characterization in Pichia Pastoris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Benzoquinone reductase (BR) is an enzyme which catalyzes the bivalent redox reactions of quinones without the production of free radical intermediates. Using 2-D PAGE, two proteins were found to be up-regulated in wild-type cotton ovules during the fiber initiation stage. These proteins were excis...

  6. JARID1B is a histone H3 lysine 4 demethylase up-regulated in prostate cancer

    E-print Network

    Tian, Weidong

    JARID1B is a histone H3 lysine 4 demethylase up-regulated in prostate cancer Yang Xiang*, Ziqi Zhu-regulated in prostate cancer tissues, compared with benign prostate samples. We also demonstrated that JARID1B-regulated in prostate cancer. demethylation methylation transcription JmjC domain Histone methylation plays an important

  7. VEGFA Expression Is Inhibited by Arsenic Trioxide in HUVECs through the Upregulation of Ets-2 and miRNA-126

    PubMed Central

    Ge, Hong-yan; Han, Zhong-jing; Tian, Pei; Sun, Wen-jie; Xue, Da-xi; Bi, Yu; Yang, Zhang-hui; Liu, Ping

    2015-01-01

    Arsenic trioxide (ATO) has been used to treat patients with acute promyelocytic leukemia. Recently, studies have shown that ATO can induce apoptosis in leukemic cells and blood vessel endothelial cells in a time- and dose-dependent manner through the inhibition of vascular endothelial growth factor A (VEGFA) production. VEGFA is a key factor in angiogenesis initiation. Targeted inhibition of VEGF or VEGFA expression can suppress angiogenesis; however, little is known about the mechanism by which ATO inhibits VEGFA expression. In this study, we investigated the role of miRNA-126 in the mechanism of action of ATO in human umbilical vein endothelial cells (HUVECs). ATO significantly decreased the viability and proliferation of HUVECs and decreased their migration at 48 h. Cell proliferation was inhibited by 50% (IC50) when 5.0 ?mol/L ATO was used. ATO treatment induced miR-126 upregulation and HUVEC apoptosis. Transfection with a miR-126 mimic significantly downregulated VEGFA mRNA levels, and transfection with a miR-126 inhibitor significantly upregulated VEGFA mRNA levels. Finally, we showed that ATO treatment upregulated Ets-2 and miR-126 expression in HUVECs. These results demonstrate that ATO inhibits the growth of HUVECs and induces apoptosis by downregulating VEGFA. One mechanism by which this occurs is Ets-2 upregulation, which results in an increase in miR-126 levels and downregulation of VEGFA expression. PMID:26274316

  8. Gene Up-Regulation in Heart during Mammalian Hibernation Andreas Fahlman, Janet M. Storey, and Kenneth B. Storey

    E-print Network

    Fahlman, Andreas

    Gene Up-Regulation in Heart during Mammalian Hibernation Andreas Fahlman, Janet M. Storey By Drive, Ottawa, Ontario, Canada K1S 5B6 A cDNA library prepared from heart of hibernating golden-regulated during hibernation. Two differentially expressed clones were found after three rounds of screening

  9. The oncoprotein HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote the proliferation of breast cancer cells

    SciTech Connect

    Zhang, Yingyi; Zhao, Yu; Li, Leilei; Shen, Yu; Cai, Xiaoli; Zhang, Xiaodong; Ye, Lihong

    2013-05-03

    Highlights: •HBXIP is able to upregulate the expression of PDGFB in breast cancer cells. •HBXIP serves as a coactivator of activating transcription factor Sp1. •HBXIP stimulates the PDGFB promoter via activating transcription factor Sp1. •HBXIP promotes the proliferation of breast cancer cell via upregulating PDGFB. -- Abstract: We have reported that the oncoprotein hepatitis B virus X-interacting protein (HBXIP) acts as a novel transcriptional coactivator to promote proliferation and migration of breast cancer cells. Previously, we showed that HBXIP was able to activate nuclear factor-?B (NF-?B) in breast cancer cells. As an oncogene, the platelet-derived growth factor beta polypeptide (PDGFB) plays crucial roles in carcinogenesis. In the present study, we found that both HBXIP and PDGFB were highly expressed in breast cancer cell lines. Interestingly, HBXIP was able to increase transcriptional activity of NF-?B through PDGFB, suggesting that HBXIP is associated with PDGFB in the cells. Moreover, HBXIP was able to upregulate PDGFB at the levels of mRNA, protein and promoter in the cells. Then, we identified that HBXIP stimulated the promoter of PDGFB through activating transcription factor Sp1. In function, HBXIP enhanced the proliferation of breast cancer cells through PDGFB in vitro. Thus, we conclude that HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote proliferation of breast cancer cells.

  10. Lipocalin-type prostaglandin D synthase is up-regulated in oligodendrocytes in lysosomal storage diseases and binds gangliosides.

    PubMed

    Mohri, Ikuko; Taniike, Masako; Okazaki, Issei; Kagitani-Shimono, Kuriko; Aritake, Kosuke; Kanekiyo, Takahisa; Yagi, Takashi; Takikita, Shoichi; Kim, Hyung-Suk; Urade, Yoshihiro; Suzuki, Kinuko

    2006-05-01

    Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) is a dually functional protein, acting both as a PGD2-synthesizing enzyme and as an extracellular transporter of various lipophilic small molecules. L-PGDS is expressed in oligodendrocytes (OLs) in the central nervous system and is up-regulated in OLs of the twitcher mouse, a model of globoid cell leukodystrophy (Krabbe's disease). We investigated whether up-regulation of L-PGDS is either unique to Krabbe's disease or is a more generalized phenomenon in lysosomal storage disorders (LSDs), using LSD mouse models of Tay-Sachs disease, Sandhoff disease, GM1 gangliosidosis and Niemann-Pick type C1 disease. Quantitative RT-PCR revealed that L-PGDS mRNA was up-regulated in the brains of all these mouse models. In addition, strong L-PGDS immunoreactivity was observed in OLs, but not in either astrocytes or microglia in these models. Thus, up-regulation of L-PGDS appears to be a common response of OLs in LSDs. Moreover, surface plasmon resonance analyses revealed that L-PGDS binds GM1 and GM2 gangliosides, accumulated in neurons in the course of LSD, with high affinities (KD = 65 and 210 nm, respectively). This suggests that L-PGDS may play a role in scavenging harmful lipophilic substrates in LSD. PMID:16515539

  11. MAREK'S DISEASE VIRUS UP-REGULATES MAJOR HISTOCOMPATIBILITY COMPLEX CLASS II CELL SURFACE EXPRESSION IN INFECTED CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many herpesviruses modulate major histocompatibility complex (MHC) expression on the cell surface as an immune evasion mechanism. We report here that Marek's disease virus (MDV), a lymphotrophic avian alphaherpesvirus, up-regulates MHC class II cell surface expression in infected cells, contrary to...

  12. Care and Feeding of the Endocannabinoid System: A Systematic Review of Potential Clinical Interventions that Upregulate the Endocannabinoid System

    PubMed Central

    McPartland, John M.; Guy, Geoffrey W.; Di Marzo, Vincenzo

    2014-01-01

    Background The “classic” endocannabinoid (eCB) system includes the cannabinoid receptors CB1 and CB2, the eCB ligands anandamide (AEA) and 2-arachidonoylglycerol (2-AG), and their metabolic enzymes. An emerging literature documents the “eCB deficiency syndrome” as an etiology in migraine, fibromyalgia, irritable bowel syndrome, psychological disorders, and other conditions. We performed a systematic review of clinical interventions that enhance the eCB system—ways to upregulate cannabinoid receptors, increase ligand synthesis, or inhibit ligand degradation. Methodology/Principal Findings We searched PubMed for clinical trials, observational studies, and preclinical research. Data synthesis was qualitative. Exclusion criteria limited the results to 184 in vitro studies, 102 in vivo animal studies, and 36 human studies. Evidence indicates that several classes of pharmaceuticals upregulate the eCB system, including analgesics (acetaminophen, non-steroidal anti-inflammatory drugs, opioids, glucocorticoids), antidepressants, antipsychotics, anxiolytics, and anticonvulsants. Clinical interventions characterized as “complementary and alternative medicine” also upregulate the eCB system: massage and manipulation, acupuncture, dietary supplements, and herbal medicines. Lifestyle modification (diet, weight control, exercise, and the use of psychoactive substances—alcohol, tobacco, coffee, cannabis) also modulate the eCB system. Conclusions/Significance Few clinical trials have assessed interventions that upregulate the eCB system. Many preclinical studies point to other potential approaches; human trials are needed to explore these promising interventions. PMID:24622769

  13. Sildenafil prevents the up-regulation of transient receptor potential canonical channels in the development of cardiomyocyte hypertrophy

    SciTech Connect

    Kiso, Hironori; Ohba, Takayoshi; Iino, Kenji; Sato, Kazuhiro; Terata, Yutaka; Murakami, Manabu; Ono, Kyoichi; Watanabe, Hiroyuki; Ito, Hiroshi

    2013-07-05

    Highlights: •Transient receptor potential canonical (TRPC1, 3 and 6) are up-regulated by ET-1. •Sildenafil inhibited hypertrophic responses (BNP, Ca entry, NFAT activation). •Sildenafil suppressed TRPC1, 3 and 6 expression. -- Abstract: Background: Transient receptor potential canonical (TRPCs) channels are up-regulated in the development of cardiac hypertrophy. Sildenafil inhibits TRPC6 activation and expression, leading to the prevention of cardiac hypertrophy. However, the effects of sildenafil on the expression of other TRPCs remain unknown. We hypothesized that in addition to its effects of TRPC6, sildenafil blocks the up-regulation of other TRPC channels to suppress cardiomyocyte hypertrophy. Methods and results: In cultured neonatal rat cardiomyocytes, a 48 h treatment with 10 nM endothelin (ET)-1 induced hypertrophic responses characterized by nuclear factor of activated T cells activation and enhancement of brain natriuretic peptide expression and cell surface area. Co-treatment with sildenafil (1 ?M, 48 h) inhibited these ET-1-induced hypertrophic responses. Although ET-1 enhanced the gene expression of TRPCs, sildenafil inhibited the enhanced gene expression of TRPC1, C3 and C6. Moreover, co-treatment with sildenafil abolished the augmentation of SOCE in the hypertrophied cardiomyocytes. Conclusions: These results suggest that sildenafil inhibits cardiomyocyte hypertrophy by suppressing the up-regulation of TRPC expression.

  14. Pseudomonas aeruginosa-dependent upregulation of TLR2 influences host responses to a secondary Staphylococcus aureus infection.

    PubMed

    Shin, Hee-Sung; Lee, Jung-Hoon; Paek, Se-Hwan; Jung, Yong Woo; Ha, Un-Hwan

    2013-11-01

    The clinical impact of polymicrobial infections has received increasing attention from the medical community. However, the potential effects of Pseudomonas aeruginosa infection on the development of host responses against Gram-positive bacteria, such as Staphylococcus aureus, are unknown. Here, P. aeruginosa infection was found to induce the expression of Toll-like receptor 2 (TLR2), which plays a dominant role in sensing pathogen-associated molecular patterns (PAMPs) expressed by Gram-positive bacteria. P. aeruginosa-dependent upregulation of TLR2 was not mediated by flagellin, or by the type III (T3SS) or type VI (T6SS) secretion systems, but was upregulated by lipopolysaccharide (LPS). Upregulation of TLR2 influenced the magnitude of proinflammatory responses to the secondary S. aureus infection, but there was no clear effect on phagocytosis of S. aureus by macrophages. Taken together, the results of this study demonstrate that P. aeruginosa infection results in the upregulation of TLR2 expression, subsequently enhancing innate immune responses against a secondary S. aureus infection. PMID:23913551

  15. Classical Macrophage Activation Up-Regulates Several Matrix Metalloproteinases through Mitogen Activated Protein Kinases and Nuclear Factor-?B

    PubMed Central

    Susana, Angela; Johnson, Jason L.; Newby, Andrew C.

    2012-01-01

    Remodelling of the extracellular matrix (ECM) and cell surface by matrix metalloproteinases (MMPs) is an important function of monocytes and macrophages. Recent work has emphasised the diverse roles of classically and alternatively activated macrophages but the consequent regulation of MMPs and their inhibitors has not been studied comprehensively. Classical activation of macrophages derived in vitro from un-fractionated CD16+/? or negatively-selected CD16? macrophages up-regulated MMP-1, -3, -7, -10, -12, -14 and -25 and decreased TIMP-3 steady-state mRNA levels. Bacterial lipopolysaccharide, IL-1 and TNF? were more effective than interferon? except for the effects on MMP-25, and TIMP-3. By contrast, alternative activation decreased MMP-2, -8 and -19 but increased MMP -11, -12, -25 and TIMP-3 steady-state mRNA levels. Up-regulation of MMPs during classical activation depended on mitogen activated protein kinases, phosphoinositide-3-kinase and inhibitor of ?B kinase-2. Effects of interferon? depended on janus kinase-2. Where investigated, similar effects were seen on protein concentrations and collagenase activity. Moreover, activity of MMP-1 and -10 co-localised with markers of classical activation in human atherosclerotic plaques in vivo. In conclusion, classical macrophage activation selectively up-regulates several MMPs in vitro and in vivo and down-regulates TIMP-3, whereas alternative activation up-regulates a distinct group of MMPs and TIMP-3. The signalling pathways defined here suggest targets for selective modulation of MMP activity. PMID:22880008

  16. T-cell accumulation and regulated on activation, normal T cell expressed and secreted upregulation in adipose tissue in obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obesity is associated with chronic inflammation, which includes increased macrophage accumulation in adipose tissue (AT) and upregulation of chemokines and cytokines. T cells also play important roles in chronic inflammatory diseases such as atherosclerosis but have not been well studied in obesity....

  17. Genes Up-Regulated in Tolerant Cavendish Banana Roots in Response to Fusarium oxysporum f. sp. cubense Infection1

    E-print Network

    Genes Up-Regulated in Tolerant Cavendish Banana Roots in Response to Fusarium oxysporum f. sp-associated genes, PAE, PR-1, PR-3, phenolic compounds Abstract Fusarium wilt of banana, caused by Fusarium Fusarium wilt of banana, caused by the soil-borne pathogen Fusarium oxysporum f. sp. cubense (Foc

  18. The alternative oxidase (AOX) gene in Vibrio fischeri is controlled by NsrR and upregulated in response to

    E-print Network

    McFall-Ngai, Margaret

    The alternative oxidase (AOX) gene in Vibrio fischeri is controlled by NsrR and upregulated Vibrio fischeri, we explore the regulation of aox expression and AOX function. Using quantitative PCR-encoding gene in Vibrio fischeri ES114, a bioluminescent marine bacterium that forms a symbiotic relationship

  19. FHOD1, a Formin Upregulated in Epithelial-Mesenchymal Transition, Participates in Cancer Cell Migration and Invasion

    PubMed Central

    Gardberg, Maria; Kaipio, Katja; Lehtinen, Laura; Mikkonen, Piia; Heuser, Vanina D.; Talvinen, Kati; Iljin, Kristiina; Kampf, Caroline; Uhlen, Mathias; Grénman, Reidar; Koivisto, Mari; Carpén, Olli

    2013-01-01

    Cancer cells can obtain their ability to invade and metastasise by undergoing epithelial-to-mesenchymal transition (EMT). Exploiting this mechanism of cellular plasticity, malignant cells can remodel their actin cytoskeleton and down-regulate proteins needed for cell-cell contacts. The mechanisms of cytoskeletal reorganisation resulting in mesenchymal morphology and increased invasive potential are poorly understood. Actin nucleating formins have been implicated as key players in EMT. Here, we analysed which formins are altered in squamous cell carcinoma related EMT. FHOD1, a poorly studied formin, appeared to be markedly upregulated upon EMT. In human tissues FHOD1 was primarily expressed in mesenchymal cells, with little expression in epithelia. However, specimens from oral squamous cell cancers demonstrated consistent FHOD1 upregulation in mesenchymally transformed cells at the invasive edge. This upregulation was confirmed in an oral squamous carcinoma model, where FHOD1 expression was markedly increased upon EMT in a PI3K signalling dependent manner. In the EMT cells FHOD1 contributed to the spindle-shaped morphology and mesenchymal F-actin organization. Furthermore, functional assays demonstrated that FHOD1 contributes to cell migration and invasion. Finally, FHOD1 depletion reduced the ability of EMT cancer cells to form invadopodia and to degrade extracellular matrix. Our results indicate that FHOD1 participates in cytoskeletal changes in EMT. In addition, we show that FHOD1 upregulation occurs during cancer cell EMT in vivo, which indicates that FHOD1 may contribute to tumour progression. PMID:24086398

  20. Novel physico-chemical diagnostic tools for high throughput identification of bovine mastitis associated gram-positive, catalase-negative cocci

    PubMed Central

    2014-01-01

    Background The routine diagnosis of Streptococcus spp. and other mastitis associated gram-positive, catalase-negative cocci is still based upon biochemical tests and serological methods, which frequently provide ambiguous identification results. We therefore aimed to establish an accurate identification system for differential diagnosis of mastitis associated Streptococcus spp. and related species using biophysical techniques such as Fourier-transform infrared (FTIR) spectroscopy and MALDI – TOF/MS. Results Based on a panel of 210 isolates from cases of bovine mastitis, an unsupervised FTIR spectral reference library was established and an artificial neural network (ANN) - assisted identification system was developed. All bacterial isolates were previously identified by species-specific PCR and/or 16S rRNA gene sequence analysis. An overall identification rate of 100% at species level for 173 strains unknown to the ANN and the library was achieved by combining ANN and the spectral database, thus demonstrating the suitability of our FTIR identification system for routine diagnosis. In addition, we investigated the potential of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of mastitis associated Streptococcus spp. and related bacteria. Using the Microflex LT System, MALDI Biotyper software™ (V3.3) we achieved an accuracy rate of 95.2%. A blind study, including 21 clinical samples from dairy cows, revealed a 100% correct species identification rate for FTIR and 90.5% for MALDI-TOF MS, indicating that these techniques are valuable tools for diagnosis. Conclusions This study clearly demonstrates that FTIR spectroscopy as well as MALDI-TOF MS can significantly improve and facilitate the identification and differentiation of mastitis associated Streptococcus spp. and related species. Although the FTIR identification system turned out being slightly superior to MALDI-TOF MS in terms of identification on species level, both methods offer interesting alternatives to conventional methods currently used in mastitis diagnosis as both of them provide high accuracy at low operating costs once the instrument is acquired. PMID:25015262

  1. Association Between Catalase Gene Polymorphisms and Risk of Chronic Hepatitis B, Hepatitis B Virus-Related Liver Cirrhosis and Hepatocellular Carcinoma in Guangxi Population

    PubMed Central

    Liu, Yanqiong; Xie, Li; Zhao, Jiangyang; Huang, Xiuli; Song, Liuying; Luo, Jingrong; Ma, Liping; Li, Shan; Qin, Xue

    2015-01-01

    Abstract Reactive oxygen species (ROS) play critical roles in hepatocarcinogenesis. The catalase (CAT) enzyme is involved in the repair of ROS. Therefore, we investigate the association between CAT gene polymorphisms and the risk of hepatocellular carcinoma (HCC). A total of 715 subjects were divided into 4 groups: 111 chronic hepatitis B (CHB) patients, 90 hepatitis B virus (HBV)-related liver cirrhosis (LC) patients, 266 HBV-HCC patients, and 248 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism strategy was used to detect CAT gene rs1001179, rs769217, and rs7943316 polymorphisms. Binary logistic regression analyses adjusting for sex, age, ethnicity, smoking and alcohol consumption, and body mass index suggested that subjects carrying the rs769217 T allele were at marginally increased risk of CHB, LC, and HCC, with adjusted odds ratios (ORs) of 1.51 (95% confidence interval [CI]?=?1.04–2.20, P?=?0.029), 1.48 (95% CI?=?1.03–2.14, P?=?0.035), and 1.51 (95% CI?=?1.14–1.98, P?=?0.004), respectively. Similarly, those individuals carrying the rs769217 TT genotype had a moderately increased risk of CHB, LC, and HCC, with adjusted ORs of 2.11 (95% CI?=?1.05–4.22, P?=?0.035), 2.00 (95% CI, 1.01–3.95, P?=?0.047), and 1.93 (95% CI?=?1.14–3.28, P?=?0.015), respectively. Moreover, subjects carrying the rs769217 CT genotype and at least 1 copy of the T allele (dominant model) were 1.78 times and 1.83 times more likely to develop HCC, respectively (OR?=?1.78, 95% CI?=?1.16–2.73, P?=?0.009 and OR?=?1.83, 95% CI?=?1.23–2.71, P?=?0.003). This association between CAT rs769217 T alleles and HCC risk is significantly strengthened among men, nonsmokers, nondrinkers, and among individuals <50 years of age. Furthermore, we found 1 high-risk haplotype GTA for CHB (OR?=?1.45, 95% CI?=?1.05–2.01) and 1 protective haplotype GCA for HCC risk (OR?=?0.67, 95% CI?=?0.52–0.87). We did not found any significant difference in CAT rs1001179 and rs7943316 polymorphisms between controls and cases. Our findings suggest that the CAT rs769217 T allele is associated with increased risk of CHB, HBV-LC, and HBV-HCC in Guangxi population. PMID:25837767

  2. Infection and upregulation of proinflammatory cytokines in human brain vascular pericytes by human cytomegalovirus

    PubMed Central

    2012-01-01

    Background Congenital human cytomegalovirus (HCMV) infections can result in CNS abnormalities in newborn babies including vision loss, mental retardation, motor deficits, seizures, and hearing loss. Brain pericytes play an essential role in the development and function of the blood–brain barrier yet their unique role in HCMV dissemination and neuropathlogy has not been reported. Methods Primary human brain vascular pericytes were exposed to a primary clinical isolate of HCMV designated ‘SBCMV’. Infectivity was analyzed by microscopy, immunofluorescence, Western blot, and qRT-PCR. Microarrays were performed to identify proinflammatory cytokines upregulated after SBCMV exposure, and the results validated by real-time quantitative polymerase chain reaction (qPCR) methodology. In situ cytokine expression of pericytes after exposure to HCMV was examined by ELISA and in vivo evidence of HCMV infection of brain pericytes was shown by dual-labeled immunohistochemistry. Results HCMV-infected human brain vascular pericytes as evidenced by several markers. Using a clinical isolate of HCMV (SBCMV), microscopy of infected pericytes showed virion production and typical cytomegalic cytopathology. This finding was confirmed by the expression of major immediate early and late virion proteins and by the presence of HCMV mRNA. Brain pericytes were fully permissive for CMV lytic replication after 72 to 96 hours in culture compared to human astrocytes or human brain microvascular endothelial cells (BMVEC). However, temporal transcriptional expression of pp65 virion protein after SBCMV infection was lower than that seen with the HCMV Towne laboratory strain. Using RT-PCR and dual-labeled immunofluorescence, proinflammatory cytokines CXCL8/IL-8, CXCL11/ITAC, and CCL5/Rantes were upregulated in SBCMV-infected cells, as were tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta), and interleukin-6 (IL-6). Pericytes exposed to SBCMV elicited higher levels of IL-6 compared to both mock-infected as well as heat-killed virus controls. A 6.6-fold induction of IL-6 and no induction TNF-alpha was observed in SBCMV-infected cell supernatants at 24 hours postinfection. Using archival brain tissue from a patient coinfected with HCMV and HIV, we also found evidence of HCMV infection of pericytes using dual-label immunohistochemistry, as monitored by NG2 proteoglycan staining. Conclusion HCMV lytic infection of primary human brain pericytes suggests that pericytes contribute to both virus dissemination in the CNS as well as neuroinflammation. PMID:22607552

  3. Genistein up-regulates tumor suppressor microRNA-574-3p in prostate cancer.

    PubMed

    Chiyomaru, Takeshi; Yamamura, Soichiro; Fukuhara, Shinichiro; Hidaka, Hideo; Majid, Shahana; Saini, Sharanjot; Arora, Sumit; Deng, Guoren; Shahryari, Varahram; Chang, Inik; Tanaka, Yuichiro; Tabatabai, Z Laura; Enokida, Hideki; Seki, Naohiko; Nakagawa, Masayuki; Dahiya, Rajvir

    2013-01-01

    Genistein has been shown to inhibit cancers both in vitro and in vivo, by altering the expression of several microRNAs (miRNAs). In this study, we focused on tumor suppressor miRNAs regulated by genistein and investigated their function in prostate cancer (PCa) and target pathways. Using miRNA microarray analysis and real-time RT-PCR we observed that miR-574-3p was significantly up-regulated in PCa cells treated with genistein compared with vehicle control. The expression of miR-574-3p was significantly lower in PCa cell lines and clinical PCa tissues compared with normal prostate cells (RWPE-1) and adjacent normal tissues. Low expression level of miR-574-3p was correlated with advanced tumor stage and higher Gleason score in PCa specimens. Re-expression of miR-574-3p in PCa cells significantly inhibited cell proliferation, migration and invasion in vitro and in vivo. miR-574-3p restoration induced apoptosis through reducing Bcl-xL and activating caspase-9 and caspase-3. Using GeneCodis software analysis, several pathways affected by miR-574-3p were identified, such as 'Pathways in cancer', 'Jak-STAT signaling pathway', and 'Wnt signaling pathway'. Luciferase reporter assays demonstrated that miR-574-3p directly binds to the 3' UTR of several target genes (such as RAC1, EGFR and EP300) that are components of 'Pathways in cancer'. Quantitative real-time PCR and Western analysis showed that the mRNA and protein expression levels of the three target genes in PCa cells were markedly down-regulated with miR-574-3p. Loss-of-function studies demonstrated that the three target genes significantly affect cell proliferation, migration and invasion in PCa cell lines. Our results show that genistein up-regulates tumor suppressor miR-574-3p expression targeting several cell signaling pathways. These findings enhance understanding of how genistein regulates with miRNA in PCa. PMID:23554959

  4. NRF2 activation is involved in ozonated human serum upregulation of HO-1 in endothelial cells

    SciTech Connect

    Pecorelli, Alessandra; Bocci, Velio; Acquaviva, Alessandra; Belmonte, Giuseppe; Gardi, Concetta; Virgili, Fabio; Ciccoli, Lucia; Valacchi, Giuseppe

    2013-02-15

    During the last decade, it has been shown that the activation of NRF2 and the binding to electrophile-responsive element (EpREs), stimulates the expression of a great number of genes responsible for the synthesis of phase I and phase II proteins, including antioxidants enzymes and heme oxygenase-1 (HO-1). This critical cell response occurs in cardiovascular, degenerative and chronic infective diseases aggravated by a chronic oxidative stress. In our previous reports we have shown that ozonated plasma is able to up-regulate HO-1 expression in endothelial cells. In the present work we investigated a candidate mechanism involved in this process. After treatment with increasing doses of ozonated serum (20, 40 and 80 ?g/mL O{sub 3} per mL of serum), a clear dose dependent activation of NRF2 and the subsequent induction of HO-1 and NAD(P)H quinone oxidoreductase 1(NQO1) was observed. This effect was also present when cells were treated with serum and hydrogen peroxide (H{sub 2}O{sub 2}) or serum and 4-hydroxynonenal (4HNE). Moreover, the treatment with ozonated serum was associated with a dose-dependent activation of extracellular-signal-regulated kinases (ERK1/2) and p38 MAP kinases (p38), not directly involved in NRF2 activation. These data, provide a new insight on the mechanism responsible for the induction of HO-1 expression by ozonated serum in the endothelium, and have a practical importance as an expedient approach to the treatment of patients with both effective orthodox drugs and ozonated autohemotherapy, targeted to the restoration of redox homeostasis. - Highlights: ? Endothelial HO1 is upregulated by ozonated plasma ? This activation is induced by NRF2 and it is ERK independent. ? 4HNE and H{sub 2}O{sub 2} are the main molecules involved in this process. ? Ozonated plasma induced a hormetic effect ? Combination of orthodox medicine and ozonated plasma can be a useful treatment.

  5. Chronic neonatal nicotine upregulates heteromeric nicotinic acetylcholine receptor binding without change in subunit mRNA expression.

    PubMed

    Huang, L Z; Winzer-Serhan, U H

    2006-10-01

    Smoking during pregnancy chronically exposes the fetus to nicotine resulting in long-term behavioral and cognitive deficits. Nicotine binds to neuronal nicotinic acetylcholine receptors (nAChRs), pentameric ligand-gated ion channels widely expressed in the nervous system. Chronic nicotine upregulates high-affinity nAChRs in animals and smokers. Here we determined if chronic nicotine treatment during a developmental period corresponding to the human third trimester regulates nAChR expression. Rat pups were intubated orally three times per day with or without nicotine (6 mg/kg/day) from postnatal day 1 to 8. Subunit mRNA expression was assessed by in situ hybridization. Expression of heteromeric and homomeric nAChR receptor was evaluated by autoradiography using (125)I-epibatidine and (125)I-alphabungarotoxin, respectively. nAChR expression was analyzed in cortex, hippocampus, thalamus and medial habenula from autoradiograms using computer assisted image analysis. Nicotine induced significant upregulation of heteromeric but not homomeric nAChRs in hippocampus, cortex and thalamus without changes in subunit mRNA expression. No effect of chronic nicotine on receptor expression was detected in the medial habenula, suggesting that nicotine's effect was mainly on alpha4beta2-type heteromeric nAChRs. The nicotine-induced upregulation was reversed after nicotine withdrawal. Receptor blockade by DHbetaE, an antagonist for heteromeric alpha4/beta2 nAChRs, did not prevent upregulation but increased expression to a similar degree as nicotine. Combination of both drugs had a cumulative effect. Thus, although transient, intermittent nicotine exposure as seen in smoking mothers is sufficient to upregulate heteromeric nAChRs during a critical period of brain development and could contribute to the behavioral deficits found in children whose mother smoked. PMID:16942759

  6. Synthesis and Characterization of Cobalt(III), Nickel(II) and Copper(II) Mononuclear Complexes with the Ligand 1,3-bis[(2-aminoethyl)amino]-2-propanol and Their Catalase-Like Activity

    PubMed Central

    Silva, Daniel M.; Visentin, Lorenzo C.; Rodrigues, Bernardo L.

    2015-01-01

    In this work, we present the synthesis and characterization of two new mononuclear complexes with the ligand 1,3-bis[(2-aminoethyl)amino]-2-propanol (HL), [Co(L)(H2O)](ClO4)2 (1), [Ni(HL)](ClO4)2 (2), as well as the known complex [Cu(HL)](ClO4)2 (3) for comparison. Their abilities to catalyze the dismutation of H2O2 and the oxidation of cyclohexane were investigated. The complexes were characterized by X-ray diffraction, elemental analysis, electronic and infrared spectroscopy, cyclic voltammetry, electrospray ionization mass spectrometry (ESI-MS) and conductivity measurements. The X-ray structures showed that the nickel (2) and copper (3) complexes are tetracoordinated, with the metal ion bound to the nitrogen atoms of the ligand. On the other hand, the cobalt complex (1) is hexacoordinated, possessing additional bonds to the alkoxo group of the ligand and to a water molecule. Neither of the complexes was able to catalyze the oxidation of cyclohexane, but all of them exhibited catalase-like activity, following Michaelis-Menten kinetics, which suggest resemblance with the catalase natural enzymes. The catalytic activity followed the order: [Ni(HL)](ClO4)2 (2) > [Cu(HL)](ClO4)2 (3) > [Co(L)(H2O)](ClO4)2 (1). As far as we know, this is the first description of a nickel complex presenting a significant catalase-like activity. PMID:26379038

  7. Upregulation of Interferon Regulatory Factor 6 Promotes Neuronal Apoptosis After Traumatic Brain Injury in Adult Rats.

    PubMed

    Lin, Yuchang; Xu, Dezhi; Li, Xiaohong; Liu, Chun; Liu, Xia; Huang, Shen; Huang, Yuwei; Liu, Xiaojuan

    2016-01-01

    The interferon regulatory factor (IRF) family was first discovered as a set of transcriptional regulators of the type I interferon system in 1988. In mammals, the IRF family includes nine members that play important roles in the immune system, oncogenesis, and apoptosis. However, the distribution and the function of IRF6 in the central nervous system are limited. In this study, we established an adult rat traumatic brain injury (TBI) model. Compared to the sham brain cortex, Western blot and immunohistochemistry showed significant upregulation of IRF6 in the ipsilateral brain cortex after TBI. Immunofluorescence double-labeling showed that IRF6 completely co-localized with neurons, not astrocytes or oligodendrocytes. Furthermore, we detected that the neuronal apoptosis marker active caspase-3 co-localized with IRF6 in neurons. Additionally, IRF6 knockdown in PC12 cells in vitro resulted in a decrease in active caspase-3 expression and an increase in Bcl-2 and p-Akt expression. We conclude that IRF6 might promote neuronal apoptosis by inhibiting Akt phosphorylation after TBI. PMID:26077898

  8. Novel adipocyte aminopeptidases are selectively upregulated by insulin in healthy and obese rats.

    PubMed

    Alponti, Rafaela Fadoni; Alves, Patricia Lucio; Silveira, Paulo Flavio

    2016-02-01

    The lack of a complete assembly of the sensitivity of subcellular aminopeptidase (AP) activities to insulin in different pathophysiological conditions has hampered the complete view of the adipocyte metabolic pathways and its implications in these conditions. Here we investigated the influence of insulin on basic AP (APB), neutral puromycin-sensitive AP (PSA), and neutral puromycin-insensitive AP (APM) in high and low density microsomal and plasma membrane fractions from adipocytes of healthy and obese rats. Catalytic activities of these enzymes were fluorometrically monitoring in these fractions with or without insulin stimulus. Canonical traffic such as insulin-regulated AP was not detected for these novel adipocyte APs in healthy and obese rats. However, insulin increased APM in low density microsomal and plasma membrane fractions from healthy rats, APB in high density microsomal fraction from obese rats and PSA in plasma membrane fraction from healthy rats. A new concept of intracellular compartment-dependent upregulation of AP enzyme activities by insulin emerges from these data. This relatively selective regulation has pathophysiological significance, since these enzymes are well known to act as catalysts and receptor of peptides directly related to energy metabolism. Overall, the regulation of each one of these enzyme activities reflects certain dysfunction in obese individuals. PMID:26577934

  9. MLN4924 induces Noxa upregulation in acute myelogenous leukemia and synergizes with Bcl-2 inhibitors.

    PubMed

    Knorr, K L B; Schneider, P A; Meng, X W; Dai, H; Smith, B D; Hess, A D; Karp, J E; Kaufmann, S H

    2015-12-01

    MLN4924 (pevonedistat), an inhibitor of the Nedd8 activating enzyme (NAE), has exhibited promising clinical activity in acute myelogenous leukemia (AML). Here we demonstrate that MLN4924 induces apoptosis in AML cell lines and clinical samples via a mechanism distinct from those observed in other malignancies. Inactivation of E3 cullin ring ligases (CRLs) through NAE inhibition causes accumulation of the CRL substrate c-Myc, which transactivates the PMAIP1 gene encoding Noxa, leading to increased Noxa protein, Bax and Bak activation, and subsequent apoptotic changes. Importantly, c-Myc knockdown diminishes Noxa induction; and Noxa siRNA diminishes MLN4924-induced killing. Because Noxa also neutralizes Mcl-1, an anti-apoptotic Bcl-2 paralog often upregulated in resistant AML, further experiments have examined the effect of combining MLN4924 with BH3 mimetics that target other anti-apoptotic proteins. In combination with ABT-199 or ABT-263 (navitoclax), MLN4924 exerts a synergistic cytotoxic effect. Collectively, these results provide new insight into MLN4924-induced engagement of the apoptotic machinery that could help guide further exploration of MLN4924 for AML. PMID:26045051

  10. Laccase is upregulated via stress pathways in the phytopathogenic fungus Sclerotinia sclerotiorum.

    PubMed

    Coman, Cristina; Mo?, Augustin C; Gal, Emese; Pârvu, Marcel; Silaghi-Dumitrescu, Radu

    2013-01-01

    We report on the factors affecting the production of the newly characterized laccase from the phytopathogenic fungus Sclerotinia sclerotiorum (Lib.) de Bary. The carbon/nitrogen ratio appears to be of great importance. Rather than a simple nutrient-rich nitrogen source, yeast extract (YE) behaves as a true laccase upregulator, apparently acting via a stress pathway. Chelidonium majus extract, a known antifungal agent, acts in a similar manner. The compound(s) in the YE responsible for enhancing laccase synthesis are suggested to be hydrolysable choline derivatives. Both extracts reduce biomass and sclerotia development and enhance laccase production, leading to an increase in laccase activity by one order of magnitude compared to controls. The pH of the medium, a well-known virulence regulator for this fungus, also acts as a true laccase regulator, though via a different mechanism. The effect of pH appeared to be linked to the acidification kinetics of the extracellular medium during fungal development. A number of other known laccase inducers were found to enhance laccase production at most twofold. PMID:23931118

  11. Phospholipase A2 up-regulation during mycorrhiza formation in Tuber borchii.

    PubMed

    Miozzi, Laura; Balestrini, Raffaella; Bolchi, Angelo; Novero, Mara; Ottonello, Simone; Bonfante, Paola

    2005-07-01

    TbSP1 is a secreted and surface-associated phospholipase A(2) previously found to be up-regulated in C- or N-deprived free-living mycelia from the ectomycorrhizal ascomycete Tuber borchii. As nutrient limitation is considered an important environmental factor favouring the transition to symbiotic status, TbSP1 was suggested to be involved in the formation of mycorrhizas. An in vitro symbiosis system between Cistus incanus and T. borchii was set up: TbSP1 mRNA levels in free-living mycelia and in mycorrhizas sampled in different districts of the plant-fungus interaction were examined. In the same samples, TbSP1 protein expression was analysed by immunoelectron microscopy. A substantially enhanced TbSP1 mRNA expression, compared with nutrient-limited but free-living mycelia, was detected in the presence of the plant and reached maximal levels in fully developed mycorrhizas. A similar expression trend was revealed by immunolocalization experiments. We have shown that TbSP1 appears to respond to two partially overlapping yet distinct stimuli: nutrient starvation and mycorrhiza formation. PMID:15948845

  12. Hypogonadism Associated with Cyp19a1 (Aromatase) Posttranscriptional Upregulation in Celf1 Knockout Mice.

    PubMed

    Boulanger, Gaella; Cibois, Marie; Viet, Justine; Fostier, Alexis; Deschamps, Stéphane; Pastezeur, Sylvain; Massart, Catherine; Gschloessl, Bernhard; Gautier-Courteille, Carole; Paillard, Luc

    2015-09-01

    CELF1 is a multifunctional RNA-binding protein that controls several aspects of RNA fate. The targeted disruption of the Celf1 gene in mice causes male infertility due to impaired spermiogenesis, the postmeiotic differentiation of male gametes. Here, we investigated the molecular reasons that underlie this testicular phenotype. By measuring sex hormone levels, we detected low concentrations of testosterone in Celf1-null mice. We investigated the effect of Celf1 disruption on the expression levels of steroidogenic enzyme genes, and we observed that Cyp19a1 was upregulated. Cyp19a1 encodes aromatase, which transforms testosterone into estradiol. Administration of testosterone or the aromatase inhibitor letrozole partly rescued the spermiogenesis defects, indicating that a lack of testosterone associated with excessive aromatase contributes to the testicular phenotype. In vivo and in vitro interaction assays demonstrated that CELF1 binds to Cyp19a1 mRNA, and reporter assays supported the conclusion that CELF1 directly represses Cyp19a1 translation. We conclude that CELF1 downregulates Cyp19a1 (Aromatase) posttranscriptionally to achieve high concentrations of testosterone compatible with spermiogenesis completion. We discuss the implications of these findings with respect to reproductive defects in men, including patients suffering from isolated hypogonadotropic hypogonadism and myotonic dystrophy type I. PMID:26169831

  13. Upregulated RIP3 Expression Potentiates MLKL Phosphorylation-Mediated Programmed Necrosis in Toxic Epidermal Necrolysis.

    PubMed

    Kim, Sue Kyung; Kim, Woo-Jung; Yoon, Jung-Ho; Ji, Jae-Hoon; Morgan, Michael J; Cho, Hyeseong; Kim, You Chan; Kim, You-Sun

    2015-08-01

    Toxic epidermal necrolysis (TEN) is a severe adverse drug reaction involving extensive keratinocyte death in the epidermis. Histologically, the skin from TEN patients exhibits separation at the dermo-epidermal junction and accompanying necrosis of epidermal keratinocytes. Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is an essential part of the cellular machinery that executes "programmed", or "regulated", necrosis and has a key role in spontaneous cell death and inflammation in keratinocytes under certain conditions. Here we show that RIP3 expression is highly upregulated in skin sections from TEN patients and may therefore contribute to the pathological damage in TEN through activation of programmed necrotic cell death. The expression level of mixed lineage kinase domain-like protein (MLKL), a key downstream component of RIP3, was not significantly different in skin lesions of TEN. However, elevated MLKL phosphorylation was observed in the skin from TEN patients, indicating the presence of RIP3-dependent programmed necrosis. Importantly, in an in vitro model of TEN, dabrafenib, an inhibitor of RIP3, prevented RIP3-mediated MLKL phosphorylation and decreased cell death. Results from this study suggest that the high expression of RIP3 in keratinocytes from TEN patients potentiates MLKL phosphorylation/activation and necrotic cell death. Thus, RIP3 represents a potential target for treatment of TEN. PMID:25748555

  14. Histamine upregulates keratinocyte MMP-9 production via the histamine H1 receptor.

    PubMed

    Gschwandtner, Maria; Purwar, Rahul; Wittmann, Miriam; Bäumer, Wolfgang; Kietzmann, Manfred; Werfel, Thomas; Gutzmer, Ralf

    2008-12-01

    Skin inflammation and the migration of cells at the site of the immune response play an important role in allergic skin diseases. It has already been described that matrix metalloproteinase 9 (MMP-9) influences tissue remodeling and facilitates cell migration by proteolytic degradation of basal membrane components. The aim of this study was to investigate MMP-9 expression on human primary keratinocytes (KCs) upon stimulation with histamine, a potent mediator in allergic responses. With ELISA and zymography, we could show that histamine induced dose-dependent upregulation of MMP-9 in cultured KCs and in punch biopsies of human skin. The histamine H(1) receptor (H(1)R) agonist beta-histine-but not agonists for H(2)R, H(3)R, and H(4)R-induced MMP-9, whereas the H(1)R antagonist clemastine blocked the effect in a dose-dependent manner. Immunohistological staining showed that histamine-induced MMP-9 led to destruction of type IV collagen at the basement membrane in healthy skin. In a coculture system of KCs and T cells, migration of T cells through an artificial basement membrane was increased after histamine stimulation of KCs. Our findings demonstrate enhanced MMP-9 production and cell migration after histamine stimulation and may represent a new mechanism by which KCs contribute to the pathology of skin diseases. PMID:18548114

  15. Iron sucrose accelerates early atherogenesis by increasing superoxide production and upregulating adhesion molecules in CKD.

    PubMed

    Kuo, Ko-Lin; Hung, Szu-Chun; Lee, Tzong-Shyuan; Tarng, Der-Cherng

    2014-11-01

    High-dose intravenous iron supplementation is associated with adverse cardiovascular outcomes in patients with CKD, but the underlying mechanism is unknown. Our study investigated the causative role of iron sucrose in leukocyte-endothelium interactions, an index of early atherogenesis, and subsequent atherosclerosis in the mouse remnant kidney model. We found that expression levels of intracellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and adhesion of U937 cells increased in iron-treated human aortic endothelial cells through upregulated NADPH oxidase (NOx) and NF-?B signaling. We then measured mononuclear-endothelial adhesion and atherosclerotic lesions of the proximal aorta in male C57BL/6 mice with subtotal nephrectomy, male apolipoprotein E-deficient (ApoE(-/-)) mice with uninephrectomy, and sham-operated mice subjected to saline or parenteral iron loading. Iron sucrose significantly increased tissue superoxide production, expression of tissue cell adhesion molecules, and endothelial adhesiveness in mice with subtotal nephrectomy. Moreover, iron sucrose exacerbated atherosclerosis in the aorta of ApoE(-/-) mice with uninephrectomy. In patients with CKD, intravenous iron sucrose increased circulating mononuclear superoxide production, expression of soluble adhesion molecules, and mononuclear-endothelial adhesion compared with healthy subjects or untreated patients. In summary, iron sucrose aggravated endothelial dysfunction through NOx/NF-?B/CAM signaling, increased mononuclear-endothelial adhesion, and exacerbated atherosclerosis in mice with remnant kidneys. These results suggest a novel causative role for therapeutic iron in cardiovascular complications in patients with CKD. PMID:24722448

  16. Chemoradiotherapy-induced upregulation of PD-1 antagonizes immunity to HPV-related oropharyngeal cancer

    PubMed Central

    Parikh, Falguni; Duluc, Dorothée; Imai, Naoko; Clark, Amelia; Misiukiewicz, Krzys; Bonomi, Marcello; Gupta, Vishal; Patsias, Alexis; Parides, Michael; Demicco, Elizabeth G.; Zhang, David Y.; Kim-Schulze, Seunghee; Kao, Johnny; Gnjatic, Sacha; Oh, Sangkon; Posner, Marshall; Sikora, Andrew G.

    2015-01-01

    While viral antigens in HPV-related oropharyngeal cancer (HPVOPC) are attractive targets for immunotherapy, the effects of existing standard-of-care therapies on immune responses to HPV are poorly understood. We serially sampled blood from stage III–IV OPC patients undergoing concomitant chemoradiotherapy (CRT) with or without induction chemotherapy. Circulating immunocytes including CD4+ and CD8+ T cells, regulatory T cells (Treg), and myeloid-derived suppressor cells (MDSC) were profiled by flow cytometry. Antigen-specific T cell responses were measured in response to HPV16 E6 and E7 peptide pools. The role of PD-1 signaling in treatment-related immunosuppression was functionally defined by performing HPV-specific T cell assays in the presence of blocking antibody. While HPV-specific T cell responses were present in 13/18 patients prior to treatment, 10/13 patients lost these responses within 3 months after CRT. CRT decreased circulating T cells and markedly elevated MDSC. PD-1 expression on CD4+ T cells increased by nearly 2.5-fold after CRT, and ex-vivo culture with PD-1 blocking antibody enhanced HPV-specific T cell responses in 8/18 samples tested. CRT suppresses circulating immune responses in HPVOPC patients by unfavorably altering effector:suppressor immunocyte ratios and upregulating PD-1 expression on CD4+ T cells. These data strongly support testing of PD-1-blocking agents in combination with standard-of-care CRT for HPVOPC. PMID:25320012

  17. Lipopolysaccharide stimulation upregulated Toll-like receptor 4 expression in chicken cerebellum.

    PubMed

    Ansari, Abdur Rahman; Wen, Le; Huang, Hai-Bo; Wang, Ji-Xiang; Huang, Xi-Yao; Peng, Ke-Mei; Liu, Hua-Zhen

    2015-08-15

    Toll-like receptors (TLRs) play crucial roles in innate and adaptive immune responses to invading pathogens. TLR4 is responsible for the recognition of bacterial lipopolysaccharide (LPS) in different parts of central nervous system of many vertebrates. To better understand the functions of TLR4 in cerebellum of chicken, present study was designed to identify the cell types that express TLR4 during postnatal stages as well as the changes in its expression in response to LPS challenge. For this purpose, cerebella were collected from chicken aged 1, 14 and 40 days (n=7 in each group) to analyze TLR4 distribution pattern. The cerebella from 14 chickens injected with LPS or sterilizing saline were also collected at Day 14 (n=7 in each group) to investigate changes in TLR4 expression. This expression was analyzed by immunohistochemistry using an anti-TLR4 antibody. TLR4 was constitutively expressed in the Purkinje cell layer, pia mater, neurons in medulla and blood vessels in the cerebellum and LPS stimulation significantly up-regulated TLR4 expression on Day 14 in the chicken cerebellum. This study provides evidence that neurons in chicken cerebellum can express TLR4 in vivo and suggests that these neurons may play an important role in initiating a defense reaction via activation of TLR4. PMID:26049167

  18. Glargine Promotes Human Colorectal Cancer Cell Proliferation via Upregulation of miR-95.

    PubMed

    Qin, J; Teng, J-A; Zhu, Z; Chen, J-X; Wu, Y-Y

    2015-10-01

    Several studies have shown a correlation between glargine use and cancer risk. However, the role of glargine in carcinogenesis, especially in colorectal cancer (CRC), is still inconclusive. The aim of this study was to investigate the influence of glargine on proliferation of CRC cells and its possible mechanism. Effect of glargine on the cell proliferation was tested in HCT-116 and SW480 cells by MTT assay, and apoptosis was measured by flow cytometry. The expression of microRNA-95 (miR-95) and sorting nexin 1 (SNX1) protein was also determined by real-time PCR and Western blotting, respectively. The results showed that high dose glargine (from 150 to 300?nM) promoted proliferation and inhibit2ed apoptosis of CRC cells compared with untreated cells. Moreover, glargine could upregulate miR-95 and downregulate SNX1 protein expression in CRC cells. These data show that glargine may indeed trigger cellular proliferation in CRC, probably by regulating miR-95. PMID:25671802

  19. NF-?B protects human neuroblastoma cells from nitric oxide-induced apoptosis through upregulating biglycan

    PubMed Central

    Wang, Lei; Cheng, Bin-Feng; Yang, Hai-Jie; Wang, Mian; Feng, Zhi-Wei

    2015-01-01

    Excessive nitric oxide (NO) produced in inflammation may result in oxidative stress, which is closely related to the neurodegenerative diseases and brain damage. Massive NO production can enhance NF-?B activity in various neural cells, but the function of this activation by NO and the target genes transactivated by NF-?B are still largely unknown. In the present study, our results showed sodium nitropruside (SNP), a NO donor, triggered apoptotic cell death and NF-?B activation in human neuroblastoma SH-EP1 cells, and inhibition of NF-?B activation by its super endogenous inhibitor, I-?B?M, sensitized SH-EP1 cells to NO-induced apoptosis. Conversely, NF-?B activation induced by insulin-like growth factor (IGF)-1 antagonizes NO-induced apoptotic cell death in SH-EP1 cells. In addition, cDNA microarray analysis showed biglycan, an extracellular glycoprotein, was up-regulated by NF-?B, and recombinant biglycan protein conferred a protective effect on NF-?B mediated NO-induced apoptotic cell death in SH-EP1 cells. These findings suggest biglycan may serve as a potential target in preventing NO-induced neurodegenerative diseases. PMID:26550454

  20. Bariatric patients have plasmatic hypercoagulability and systemic upregulation of heme oxygenase activity.

    PubMed

    Nielsen, Vance G; Galvani, Carlos A; Boyle, Patrick K; Steinbrenner, Evangelina B; Matika, Ryan W

    2015-03-01

    Morbid obesity is associated with significant thrombophilia. Of interest, adipocytes obtained from obese patients have increased heme oxygenase (Hmox) activity, the endogenous enzyme responsible for carbon monoxide (CO) production. Given that CO enhances plasmatic coagulation, we determined whether morbidly obese patients undergoing bariatric surgery had an increase in endogenous CO and plasmatic hypercoagulability. CO was determined by noninvasive pulse oximetry measurement of carboxyhemoglobin (COHb). A thrombelastographic method to assess plasma coagulation kinetics and formation of carboxyhemefibrinogen (COHF) was utilized. Nonsmoking bariatric patients (n?=?20, BMI 47?±?8?kg/m, mean?±?SD) had abnormally increased COHb concentrations of 2.7?±?1.9%, indicative of Hmox upregulation. When coagulation kinetics of these bariatric patients were compared with values obtained from normal individuals' (n?=?30) plasma, 70% (95% confidence interval 45.7-88.1%) had abnormally great velocity of clot formation, abnormally large clot strength, and COHF formation. Future investigation of Hmox-derived CO in the pathogenesis of obesity-related thrombophilia is warranted. PMID:25101516

  1. Up-regulation of PSMB4 is associated with neuronal apoptosis after neuroinflammation induced by lipopolysaccharide.

    PubMed

    Shi, Jiansheng; Liu, Xiaorong; Xu, Changde; Ge, Jianbin; Ren, Jianbing; Wang, Jun; Song, Xinjian; Dai, Shirong; Tao, Weidong; Lu, Hongjian

    2015-12-01

    Proteasomes are major intracellular extralysosomal organelle for protein degradation and a central source of antigenic peptides in the endogenous pathway. Proteasome beta-4 subunit (PSMB4) was recently identified as potential cancer driver genes in several tumors. However, information regarding its regulation and possible function in the central nervous system is still limited. The present study was designed to elucidate dynamic changes in PSMB4 expression and distribution in the cerebral cortex in a lipopolysaccharide (LPS)-induced neuroinflammation rat model. It was found that PSMB4 expression was increased significantly in apoptotic neurons in the brain cortex after LPS injection. Moreover, there was a concomitant up-regulation of active caspase-3, cyclin D1, and CDK4 in vivo and vitro studies. In addition, these three proteins in cortical primary neurons were decreased after knocking down PSMB4 by siRNA. Collectively, these results suggested that PSMB4 may be involved in neuronal apoptosis in neuroinflammation after LPS injection. PMID:26282113

  2. Ubiquitin-proteasome system components are up-regulated during intestinal regeneration

    PubMed Central

    Pasten, Consuelo; Ortiz-Pineda, Pablo A.; E.García-Arrarás, José

    2011-01-01

    The ubiquitin proteasome system (UPS) is the main proteolytic system of cells. Recent evidence suggests that the UPS plays a regulatory role in regeneration processes. Here we explore the possibility that the UPS is involved during intestinal regeneration of the sea cucumber Holothuria glaberrima. These organisms can regenerate most of their digestive tract following a process of evisceration. Initially, we