DOCSLIB.ORG

Open Full Page

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Open Full Page Research Article Mutation Accumulation in the Intestine and Colon of Mice Deficient in Two Intracellular Glutathione Peroxidases Dong-Hyun Lee,1 R. Steven Esworthy,2 Christy Chu,2 Gerd P. Pfeifer,1 and Fong-Fong Chu2 1Department of Biology and 2Department of Radiation Biology, City of Hope Cancer Center, Duarte, California Abstract Inflammatory diseases are often associated with significant oxidative stress that can damage cells and tissues. A link between Mice deficient in two glutathione peroxidases (GPX), Gpx1 and inflammation and cancer is well established (4, 6, 7). An increased Gpx2, [Gpx1/2-double knockout (DKO) mice] are prone to incidence of cancer is seen in patients with chronic gastritis, ileocolitis on a mixed C57BL/6 and 129S1/SvJ (B6.129) genetic chronic pancreatitis, and inflammatory bowel disease (IBD; refs. 4, background. We reported previously that f25% of B6.129 7–9). IBD includes Crohn’s disease (CD) and ulcerative colitis (UC); Gpx1/2-DKO mice develop ileocolonic tumors by 6 to 9 each affects approximately one in a thousand people in Western months of age, when their non-DKO littermates [having at countries. Although CD and UC may have different genetic origins least one wild-type (WT) Gpx1 or Gpx2 allele] rarely have and affect different areas of the gastrointestinal tract, both inflammation and none have tumors. Because genetic back- diseases result in an increased risk of cancer compared with the ground affects tumor susceptibility, we have generated a B6 age-matched general population (10, 11). Clearly, chronic inflam- Gpx1/2-DKO colony and discovered that these mice have mation contributes to carcinogenesis in the gastrointestinal tract; fewer inflammatory cells, milder ileocolitis, and low mortality, however, the mechanisms are not understood. and only 2.5% of B6 mice developed tumors. The mutant Inflammation is caused by the recruitment of inflammatory frequency of a cII reporter gene was about 2- to 3-fold higher cells, including neutrophils, monocytes, and eosinophils (7), which in 28-day-old Gpx1/2-DKO and 4-fold higher in 8-month-old release ROS. Chronic inflammation can be a tumor promoter, Gpx1/2-DKO ileal mucosa than in controls in both genetic which may affect signal transduction mechanisms, influence cell backgrounds. In contrast, mutant frequencies in the unaffected proliferation, and modulate apoptosis. However, it is also possible B6 liver were not significantly different between WT and Gpx1/ that inflammation acts as a tumor initiator by inducing DNA 2-DKO mice. The mutant frequency of 8-month-old B6.129 À damage and gene mutations in the affected tissue. Such a proposal, Gpx1/2-DKO ileum was 38.94 F 15.5 5, which was not signifi- À in which inflammation, DNA damage, increased mutations, and cantly higher than the age-matched B6 ileum, 25.54 F 10.33 5. tumorigenesis are directly linked in consecutive steps, has been The mutation spectra analysis has shown that B6 Gpx1/2-DKO put forward (12). ileum had a 3-fold increase in small nucleotide deletions at Selenium-dependent glutathione peroxidases (GPX) represent mononucleotide repeats over control B6, which are a signa- a major selenoprotein-containing gene family in mammals. The ture mutation associated with oxidative stress. Unexpectedly, GPXs include four selenium-dependent hydroperoxide-reducing B6 Gpx1/2-DKO mice had fewer C to T transitions at CpG isozymes: (a) the ubiquitous GPX1, (b) the epithelium-specific GPX dinucleotides than the WT B6 (18.0% versus 40.1%; P < 0.001). (GPX2), (c) the secreted plasma GPX (GPX-P), and (d)the Our results suggest that inflammation drives gene mutations, monomeric phospholipid hydroperoxide GPX (PHGPX), which are which leads to neoplastic transformation of intestinal epithe- encoded by the Gpx1, Gpx2, Gpx3, and Gpx4 genes, respectively lium in the B6.129 Gpx1/2-DKO mice but rarely in the B6 (13). Among these GPXs, GPX1 and GPX2 are the major H2O2- Gpx1/2-DKO mice. (Cancer Res 2006; 66(20): 9845-51) reducing GPX activities in the gastrointestinal epithelium. The GPX1 and GPX2 isozymes have very similar properties, such as Introduction substrate specificity and cytosolic localization. They both reduce Oxidative stress occurs when the generation of reactive oxygen H2O2 and fatty acid hydroperoxides very efficiently but reduce lipid species (ROS) in a system exceeds the antioxidant capacity to hydroperoxides poorly. Unlike the ubiquitous GPX1, GPX2 is neutralize and eliminate them (1–4). This imbalance can result expressed mainly in epithelium, most highly in the gastrointestinal from a lack of available antioxidants or from an overabundance of epithelium. We found that, although homozygous mice deficient in ROS from environmental or internal sources. An excess of ROS either the wild-type (WT) Gpx1 or Gpx2 alleles appeared to be can damage cellular macromolecules, such as lipids, proteins, normal under standard housing conditions, homozygous Gpx1 and and nucleic acids. For example, ROS can directly interact with Gpx2 double knockout mice (Gpx1/2-DKO), with combined nucleic acids, resulting in a variety of modifications, including base disruption of both Gpx1 and Gpx2 genes, are highly susceptible damage, sugar damage, deletions, cross-linked lesions, and DNA to ileocolitis beginning around weaning (14). Similar to other strand breaks (1, 3, 5). mouse IBD models, when these mice are derived into germ-free conditions, they are disease-free (15). With long-term follow-up, the tumor incidence in Gpx1/2-DKO mice raised conventionally is f25% in mice harboring Helicobacter hepaticus (an enterohepatic Note: Supplementary data for this article are available at Cancer Research Online (http://cancerres.aacrjournals.org/). Helicobacter species that can cause colitis in immunodeficient Requests for reprints: Gerd P. Pfeifer, Beckman Research Institute of the City of mice; ref. 16) on a mixed B6.129genetic background (17). Oxidative Hope, 1450 East Duarte Road, Duarte, CA 91010. Phone: 626-301-8853; Fax: 626-358- stress associated with cellular damage is thought to play a key 7704; E-mail: [email protected]. I2006 American Association for Cancer Research. role in the pathogenesis of the colitis itself (8, 9). Lack of the doi:10.1158/0008-5472.CAN-06-0732 antioxidant GPX system in the intestinal mucosa may set up a www.aacrjournals.org 9845 Cancer Res 2006; 66: (20). October 15, 2006 Downloaded from cancerres.aacrjournals.org on September 23, 2021. © 2006 American Association for Cancer Research. Cancer Research continuous cycle of ROS and inflammation; inflammation and staff pathologists on H&E-stained sections. When harvesting DNA for cII production of ROS by inflammatory cells eventually leads to mutation analysis, we excluded mice with tumors. cancer. DNA isolation. Epithelial cells were isolated from the distal 10 to 12 cm Because inflammatory responses produce DNA-damaging oxi- of the ileum (lower 60% of small intestine, corresponding to the diseased segment in Gpx1/2-DKO mice at the height of pathology and distribution dative species and chronic inflammation in the gastrointestinal of tumors) and total colon (less f0.5 cm flanking segments taken for tract can cause cancer, we hypothesized that inflammation drives histology) by the everted sac method as described previously (22) to recover gene mutations, which can lead to carcinogenesis. To test this the villus and crypt compartments. The cells were rinsed in PBS thrice and hypothesis in a mouse model of IBD, we compared mutation frozen at À80jC. Genomic DNA was isolated using a standard phenol and frequencies and mutation spectra of the cII reporter gene in the chloroform extraction and ethanol precipitation protocol (23). Liver DNA affected intestinal and unaffected liver tissues of Gpx1/2-DKO and was isolated using a NaCl method. Briefly, the excised tissue was control mice on both B6.129and B6 genetic background. Because homogenized in 4 mL cold PBS in a 7 mL Wheaton Dounce tissue grinder GPX1 is up-regulated by p53 activation (18) and GPX2 by p63 (19), (Millville, NJ), washed twice with PBS, and lysed with 4 mL of a solution a homologue of p53, to inhibit oxidative stress–induced apoptosis, containing 0.5 mol/L Tris-HCl (pH 8.0), 20 mmol/L EDTA, 10 mmol/L NaCl, j studying the effect of GPXs in prevention of gene mutations may 1% SDS, and 0.5 mg/mL proteinase K at 37 C overnight. Subsequently, 2 mL saturated NaCl (f6 mol/L) was added to each sample, and the samples provide an insight to the mechanism of action of these antioxidant were incubated at 56jC for 10 minutes. After centrifugation at 5,000 Â g enzymes in IBD-associated tumorigenesis. for 30 minutes, the supernatant containing the DNA was mixed with 2 volumes of cold 100% ethanol, and the DNA was spooled by gently inverting the mix. The DNA was washed thoroughly with 70% ethanol, air Materials and Methods dried, and subsequently dissolved in TE buffer (pH 8.0), and kept at À80jC Animal breeding. We have established the B6.129Gpx1/2-DKO mouse until further analysis. colony as described previously (14). Breeders were maintained on diet 5020 cII mutant frequency analysis. The cII mutant frequency was (Laboratory Rodent Diet, Purina Mills, Inc., Richmond, IN) with 9% fat. examined by using the select-cII mutation detection system for Big Blue At weaning, pups were placed on diet 5001 with 5% fat until recruitment rodents as described previously (24). The assay is based on the ability of the into breeding. To generate a B6 Gpx1/2-DKO colony, the B6.129mice were phage to multiply either lytically or lysogenically in Escherichia coli host back-crossed to B6 for seven generations. B6 Gpx1/2-DKO males were bred cells. Briefly, we recovered the LIZ shuttle vectors from mouse genomic to homozygous B6 Big Blue females (Stratagene, La Jolla, CA) carrying a DNA (5 Ag) and packaged them into viable phage particles using the tandem array of E genomes (kLIZ) containing mutational reporter genes, Transpack packaging extract (Stratagene).
Load more

Recommended publications
  • MPO) in Inflammatory Communication
    antioxidants Review The Enzymatic and Non-Enzymatic Function of Myeloperoxidase (MPO) in Inflammatory Communication Yulia Kargapolova * , Simon Geißen, Ruiyuan Zheng, Stephan Baldus, Holger Winkels * and Matti Adam Department III of Internal Medicine, Heart Center, Faculty of Medicine and University Hospital of Cologne, 50937 North Rhine-Westphalia, Germany; [email protected] (S.G.); [email protected] (R.Z.); [email protected] (S.B.); [email protected] (M.A.) * Correspondence: [email protected] (Y.K.); [email protected] (H.W.) Abstract: Myeloperoxidase is a signature enzyme of polymorphonuclear neutrophils in mice and humans. Being a component of circulating white blood cells, myeloperoxidase plays multiple roles in various organs and tissues and facilitates their crosstalk. Here, we describe the current knowledge on the tissue- and lineage-specific expression of myeloperoxidase, its well-studied enzymatic activity and incoherently understood non-enzymatic role in various cell types and tissues. Further, we elaborate on Myeloperoxidase (MPO) in the complex context of cardiovascular disease, innate and autoimmune response, development and progression of cancer and neurodegenerative diseases. Keywords: myeloperoxidase; oxidative burst; NETs; cellular internalization; immune response; cancer; neurodegeneration Citation: Kargapolova, Y.; Geißen, S.; Zheng, R.; Baldus, S.; Winkels, H.; Adam, M. The Enzymatic and Non-Enzymatic Function of 1. Introduction. MPO Conservation Across Species, Maturation in Myeloid Progenitors, Myeloperoxidase (MPO) in and its Role in Immune Responses Inflammatory Communication. Myeloperoxidase (MPO) is a lysosomal protein and part of the organism’s host-defense Antioxidants 2021, 10, 562. https:// system. MPOs’ pivotal function is considered to be its enzymatic activity in response to doi.org/10.3390/antiox10040562 invading pathogenic agents.
    [Show full text]
  • Lncrna-MEG3 Functions As Ferroptotic Promoter to Mediate OGD Combined High Glucose-Induced Death of Rat Brain Microvascular Endothelial Cells Via the P53-GPX4 Axis
    LncRNA-MEG3 functions as ferroptotic promoter to mediate OGD combined high glucose-induced death of rat brain microvascular endothelial cells via the p53-GPX4 axis Cheng Chen Xiangya Hospital Central South University Yan Huang Xiangya Hospital Central South University Pingping Xia Xiangya Hospital Central South University Fan Zhang Xiangya Hospital Central South University Longyan Li Xiangya Hospital Central South University E Wang Xiangya Hospital Central South University Qulian Guo Xiangya Hospital Central South University Zhi Ye ( [email protected] ) Xiangya Hospital Central South University https://orcid.org/0000-0002-7678-0926 Research article Keywords: lncRNA-MEG3, p53, ferroptosis, ischemia, GPX4, OGD, hyperglycemia, Posted Date: May 18th, 2020 DOI: https://doi.org/10.21203/rs.3.rs-28622/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Page 1/21 Abstract Background Individuals with diabetes are exposed to a higher risk of perioperative stroke than non- diabetics mainly due to persistent hyperglycemia. lncRNA-MEG3 (long non-coding RNA maternally expressed gene 3) has been considered as an important mediator in regulating ischemic stroke. However, the functional and regulatory roles of lncRNA-MEG3 in diabetic brain ischemic injury remain unclear. Results In this study, RBMVECs (the rat brain microvascular endothelial cells) were exposed to 6 h of OGD (oxygen and glucose deprivation), and subsequent reperfusion via incubating cells with glucose of various high concentrations for 24 h to imitate in vitro diabetic brain ischemic injury. It was shown that the marker events of ferroptosis and increased lncRNA-MEG3 expression occurred after the injury induced by OGD combined with hyperglycemic treatment.
    [Show full text]
  • Role of Oxidative Stress and Nrf2/KEAP1 Signaling in Colorectal Cancer: Mechanisms and Therapeutic Perspectives with Phytochemicals
    antioxidants Review Role of Oxidative Stress and Nrf2/KEAP1 Signaling in Colorectal Cancer: Mechanisms and Therapeutic Perspectives with Phytochemicals Da-Young Lee, Moon-Young Song and Eun-Hee Kim * College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Seongnam 13488, Korea; [email protected] (D.-Y.L.); [email protected] (M.-Y.S.) * Correspondence: [email protected]; Tel.: +82-31-881-7179 Abstract: Colorectal cancer still has a high incidence and mortality rate, according to a report from the American Cancer Society. Colorectal cancer has a high prevalence in patients with inflammatory bowel disease. Oxidative stress, including reactive oxygen species (ROS) and lipid peroxidation, has been known to cause inflammatory diseases and malignant disorders. In particular, the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-related protein 1 (KEAP1) pathway is well known to protect cells from oxidative stress and inflammation. Nrf2 was first found in the homolog of the hematopoietic transcription factor p45 NF-E2, and the transcription factor Nrf2 is a member of the Cap ‘N’ Collar family. KEAP1 is well known as a negative regulator that rapidly degrades Nrf2 through the proteasome system. A range of evidence has shown that consumption of phytochemicals has a preventive or inhibitory effect on cancer progression or proliferation, depending on the stage of colorectal cancer. Therefore, the discovery of phytochemicals regulating the Nrf2/KEAP1 axis and Citation: Lee, D.-Y.; Song, M.-Y.; verification of their efficacy have attracted scientific attention. In this review, we summarize the role Kim, E.-H. Role of Oxidative Stress of oxidative stress and the Nrf2/KEAP1 signaling pathway in colorectal cancer, and the possible and Nrf2/KEAP1 Signaling in utility of phytochemicals with respect to the regulation of the Nrf2/KEAP1 axis in colorectal cancer.
    [Show full text]
  • The C718T Polymorphism in the 3″-Untranslated
    Hypertension Research (2012) 35, 507–512 & 2012 The Japanese Society of Hypertension All rights reserved 0916-9636/12 www.nature.com/hr ORIGINAL ARTICLE The C718T polymorphism in the 3¢-untranslated region of glutathione peroxidase-4 gene is a predictor of cerebral stroke in patients with essential hypertension Alexey V Polonikov1, Ekaterina K Vialykh2, Mikhail I Churnosov3, Thomas Illig4, Maxim B Freidin5, Oksana V Vasil¢eva1, Olga Yu Bushueva1, Valentina N Ryzhaeva1, Irina V Bulgakova1 and Maria A Solodilova1 In the present study we have investigated the association of three single nucleotide polymorphisms in glutathione peroxidase (GPx) genes GPX1 rs1050450 (P198L), GPX3 rs2070593 (G930A) and GPX4 rs713041 (T718C) with the risk of cerebral stroke (CS) in patients with essential hypertension (EH). A total of 667 unrelated EH patients of Russian origin, including 306 hypertensives (the EH–CS group) who suffered from CS and 361 people (the EH–CS group) who did not have cerebrovascular accidents, were enrolled in the study. The variant allele 718C of the GPX4 gene was found to be significantly associated with an increased risk of CS in hypertensive patients (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.23–1.90, Padj¼0.0003). The prevalence of the 718TC and 718CC genotypes of the GPX4 gene was higher in the EH–CS group than the EH-alone group (OR¼2.12, 95%CI 1.42–3.16, Padj¼0.0018). The association of the variant GPX4 genotypes with the increased risk of CS in hypertensives remained statistically significant after adjusting for confounding variables such as sex, body mass index (BMI), blood pressure and antihypertensive medication use (OR¼2.18, 95%CI 1.46–3.27, P¼0.0015).
    [Show full text]
  • Programmed Cell-Death by Ferroptosis: Antioxidants As Mitigators
    International Journal of Molecular Sciences Review Programmed Cell-Death by Ferroptosis: Antioxidants as Mitigators Naroa Kajarabille 1 and Gladys O. Latunde-Dada 2,* 1 Nutrition and Obesity Group, Department of Nutrition and Food Sciences, University of the Basque Country (UPV/EHU), 01006 Vitoria, Spain; [email protected] 2 King’s College London, Department of Nutritional Sciences, Faculty of Life Sciences and Medicine, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK * Correspondence: [email protected] Received: 9 September 2019; Accepted: 2 October 2019; Published: 8 October 2019 Abstract: Iron, the fourth most abundant element in the Earth’s crust, is vital in living organisms because of its diverse ligand-binding and electron-transfer properties. This ability of iron in the redox cycle as a ferrous ion enables it to react with H2O2, in the Fenton reaction, to produce a hydroxyl radical ( OH)—one of the reactive oxygen species (ROS) that cause deleterious oxidative damage • to DNA, proteins, and membrane lipids. Ferroptosis is a non-apoptotic regulated cell death that is dependent on iron and reactive oxygen species (ROS) and is characterized by lipid peroxidation. It is triggered when the endogenous antioxidant status of the cell is compromised, leading to lipid ROS accumulation that is toxic and damaging to the membrane structure. Consequently, oxidative stress and the antioxidant levels of the cells are important modulators of lipid peroxidation that induce this novel form of cell death. Remedies capable of averting iron-dependent lipid peroxidation, therefore, are lipophilic antioxidants, including vitamin E, ferrostatin-1 (Fer-1), liproxstatin-1 (Lip-1) and possibly potent bioactive polyphenols.
    [Show full text]
  • Myeloperoxidase-Mediated Platelet Release Reaction
    Myeloperoxidase-Mediated Platelet Release Reaction Robert A. Clark J Clin Invest. 1979;63(2):177-183. https://doi.org/10.1172/JCI109287. Research Article The ability of the neutrophil myeloperoxidase-hydrogen peroxide-halide system to induce the release of human platelet constituents was examined. Both lytic and nonlytic effects on platelets were assessed by comparison of the simultaneously measured release of a dense-granule marker, [3H]serotonin, and a cytoplasmic marker, [14C]adenine. Incubation of platelets with H2O2 alone (20 μM H2O2 for 10 min) resulted in a small, although significant, release of both serotonin and adenine, suggesting some platelet lysis. Substantial release of these markers was observed only with increased H2O2 concentrations (>0.1 mM) or prolonged incubation (1-2 h). Serotonin release by H2O2 was markedly enhanced by the addition of myeloperoxidase and a halide. Under these conditions, there was a predominance of release of serotonin (50%) vs. adenine (13%), suggesting, in part, a nonlytic mechanism. Serotonin release by the complete peroxidase system was rapid, reaching maximal levels in 2-5 min, and was active at H2O2 concentrations as low as 10 μM. It was blocked by agents which inhibit peroxidase (azide, cyanide), 2+ degrade H2O2 (catalase), chelate Mg (EDTA, but not EGTA), or inhibit platelet metabolic activity (dinitrophenol, deoxyglucose). These results suggest that the myeloperoxidase system initiates the release of platelet constituents primarily by a nonlytic process analogous to the platelet release reaction. Because components of the peroxidase system (myeloperoxidase, H2O2) are secreted by activated neutrophils, the reactions described here […] Find the latest version: https://jci.me/109287/pdf Myeloperoxidase-Mediated Platelet Release Reaction ROBERT A.
    [Show full text]
  • GRAS Notice 665, Lactoperoxidase System
    GRAS Notice (GRN) No. 665 http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/default.htm ORIGINAL SUBMISSION 000001 Mo•·gan Lewis Gf<N Ob()&h5 [R1~~~~~~[Q) Gary L. Yingling Senior Counsel JUL 1 8 2016 + 1.202. 739 .5610 gary.yingling@morganlewis .com OFFICE OF FOO~ ADDITIVE SAFETY July 15, 2016 VIA FEDERAL EXPRESS Dr. Antonia Mattia Director Division of Biotechnology and GRAS Notice Review Office of Food Additive Safety (HFS-200) Center for Food Safety and Applied Nutrition Food and Drug Administration 5100 Paint Branch Parkway College Park, MD 20740-3835 Re: GRAS Notification for the Lactoperoxidase System Dear Dr. Mattia: On behalf of Taradon Laboratory C'Taradon"), we are submitting under cover of this letter three paper copies and one eCopy of DSM's generally recognized as safe ("GRAS'') notification for its lactoperoxidase system (''LPS''). The electronic copy is provided on a virus-free CD, and is an exact copy of the paper submission. Taradon has determined through scientific procedures that its lactoperoxidase system preparation is GRAS for use as a microbial control adjunct to standard dairy processing procedures such as maintaining appropriate temperatures, pasteurization, or other antimicrobial treatments to extend the shelf life of the products. In many parts of the world, the LPS has been used to protect dairy products, particularly in remote areas where farmers are not in close proximity to the market. In the US, the LPS is intended to be used as a processing aid to extend the shelf life of avariety of dairy products, specifically fresh cheese including mozzarella and cottage cheeses, frozen dairy desserts, fermented milk, flavored milk drinks, and yogurt.
    [Show full text]
  • Characterization of Cytosolic Glutathione Peroxidase And
    Aquatic Toxicology 130–131 (2013) 97–111 Contents lists available at SciVerse ScienceDirect Aquatic Toxicology jou rnal homepage: www.elsevier.com/locate/aquatox Characterization of cytosolic glutathione peroxidase and phospholipid-hydroperoxide glutathione peroxidase genes in rainbow trout (Oncorhynchus mykiss) and their modulation by in vitro selenium exposure a a b a d c a,∗ D. Pacitti , T. Wang , M.M. Page , S.A.M. Martin , J. Sweetman , J. Feldmann , C.J. Secombes a Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom b Integrative and Environmental Physiology, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom c Trace Element Speciation Laboratory, Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, United Kingdom d Alltech Biosciences Centre, Sarney, Summerhill Rd, Dunboyne, Country Meath, Ireland a r t i c l e i n f o a b s t r a c t Article history: Selenium (Se) is an oligonutrient with both essential biological functions and recognized harmful effects. Received 4 July 2012 As the selenocysteine (SeCys) amino acid, selenium is integrated in several Se-containing proteins Received in revised form (selenoproteins), many of which are fundamental for cell homeostasis. Nevertheless, selenium may exert 19 December 2012 toxic effects at levels marginally above those required, mainly through the generation of reactive oxygen Accepted 20 December 2012 species (ROS). The selenium chemical speciation can strongly affect the bioavailability of this metal and its impact on metabolism, dictating the levels that can be beneficial or detrimental towards an organism.
    [Show full text]
  • Myeloperoxidase Modulates Hydrogen Peroxide Mediated Cellular Damage in Murine Macrophages
    antioxidants Article Myeloperoxidase Modulates Hydrogen Peroxide Mediated Cellular Damage in Murine Macrophages Chaorui Guo, Inga Sileikaite, Michael J. Davies and Clare L. Hawkins * Department of Biomedical Sciences, University of Copenhagen, Panum, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark; [email protected] (C.G.); [email protected] (I.S.); [email protected] (M.J.D.) * Correspondence: [email protected]; Tel.: +45-35337005 Received: 29 September 2020; Accepted: 7 December 2020; Published: 10 December 2020 Abstract: Myeloperoxidase (MPO) is involved in the development of many chronic inflammatory diseases, in addition to its key role in innate immune defenses. This is attributed to the excessive production of hypochlorous acid (HOCl) by MPO at inflammatory sites, which causes tissue damage. This has sparked wide interest in the development of therapeutic approaches to prevent HOCl-induced cellular damage including supplementation with thiocyanate (SCN−) as an alternative substrate for MPO. In this study, we used an enzymatic system composed of glucose oxidase (GO), glucose, and MPO in the absence and presence of SCN−, to investigate the effects of generating a continuous flux of oxidants on macrophage cell function. Our studies show the generation of hydrogen peroxide (H2O2) by glucose and GO results in a dose- and time-dependent decrease in metabolic activity and cell viability, and the activation of stress-related signaling pathways. Interestingly, these damaging effects were attenuated by the addition of MPO to form HOCl. Supplementation with SCN−, which favors the formation of hypothiocyanous acid, could reverse this effect. Addition of MPO also resulted in upregulation of the antioxidant gene, NAD(P)H:quinone acceptor oxidoreductase 1.
    [Show full text]
  • Involvement of Glutathione Peroxidases in the Occurrence And
    Zhang et al. J Transl Med (2020) 18:247 https://doi.org/10.1186/s12967-020-02420-x Journal of Translational Medicine REVIEW Open Access Involvement of glutathione peroxidases in the occurrence and development of breast cancers Man‑Li Zhang1†, Hua‑Tao Wu2†, Wen‑Jia Chen1,3, Ya Xu1, Qian‑Qian Ye1,3, Jia‑Xin Shen4 and Jing Liu1,3* Abstract Glutathione peroxidases (GPxs) belong to a family of enzymes that is important in organisms; these enzymes pro‑ mote hydrogen peroxide metabolism and protect cell membrane structure and function from oxidative damage. Based on the establishment and development of the theory of the pathological roles of free radicals, the role of GPxs has gradually attracted researchers’ attention, and the involvement of GPxs in the occurrence and development of malignant tumors has been shown. On the other hand, the incidence of breast cancer in increasing, and breast cancer has become the leading cause of cancer‑related death in females worldwide; breast cancer is thought to be related to the increased production of reactive oxygen species, indicating the involvement of GPxs in these processes. Therefore, this article focused on the molecular mechanism and function of GPxs in the occurrence and development of breast cancer to understand their role in breast cancer and to provide a new theoretical basis for the treatment of breast cancer. Keywords: Glutathione peroxidase, Breast cancer, Reactive oxygen species, Occurrence Background [4]. However, the mechanisms of the occurrence, devel- Breast cancer has become the most common cancer and opment, and metastasis of breast cancer are very com- the leading cause of cancer-related deaths in females plicated and overlap, suggesting the necessity of diferent worldwide, according to a status report on the global therapies to treat diferent subtypes of breast cancer.
    [Show full text]
  • Kinetics of Interconversion of Redox Intermediates of Lactoperoxidase
    Jpn. J. Infect. Dis., 57, 2004 Kinetics of Interconversion of Redox Intermediates of Lactoperoxidase, Eosinophil Peroxidase and Myeloperoxidase Paul Georg Furtmüller, Walter Jantschko, Martina Zederbauer, Christa Jakopitsch, Jürgen Arnhold1 and Christian Obinger* Metalloprotein Research Group, Division of Biochemistry, Department of Chemistry, BOKU-University of Natural Resources and Applied Life Sciences, 1Institute of Medical Physics and Biophysics, School of Medicine, University of Leipzig, Leipzig, Germany SUMMARY: Myeloperoxidase, eosinophil peroxidase and lactoperoxidase are heme-containing oxidoreductases, which undergo a series of redox reactions. Though sharing functional and structural homology, reflecting their phylogenetic origin, differences are observed regarding their spectral features, substrate specificities, redox properties and kinetics of interconversion of the relevant redox intermediates ferric and ferrous peroxidase, compound I, compound II and compound III. Depending on substrate availability, these heme enzymes path through the halogenation cycle and/or the peroxidase cycle and/or act as poor (pseudo-) catalases. Today - based on sequence homologies, tertiary structure and the halide ions is the following: I– > Br– > Cl–. All peroxidases can nature of the heme group - two heme peroxidase superfamilies are oxidize iodide. At neutral pH, only MPO is capable to oxidize distinguished, namely the superfamily containing enzymes from chloride at a reasonable rate (4), and it is assumed that chloride and archaea, bacteria, fungi and plants (1) and the superfamily of thiocyanate are competing substrates in vivo. EPO can oxidize mammalian enzymes (2), which contains myeloperoxidase (MPO), chloride only at acidic pH (5), and at normal plasma concentrations, eosinophil peroxidase (EPO), lactoperoxidase (LPO) and thyroid bromide and thiocyanate function as substrates, whereas for LPO peroxidase (TPO).
    [Show full text]
  • Positive Granules in Normal Circulating Neutrophils: an Ultrastructural Study by Cryosection
    Histol Histopathol (1998) 13: 405-414 Histology and 001: 10.14670/HH-13.405 Histopathology http://www.hh.um.es From Cell Biology to Tissue Engineering Morphological heterogeneity of myeloperoxidase­ positive granules in normal circulating neutrophils: an ultrastructural study by cryosection N. Saitol, F. Satol, M. Asakal, N. Takemori2 and Y. Kohgo3 1Third Department of Internal Medicine, Hokkaido University School of Medicine, Sapporo, Hokkaido, 2Asahikawa Kohosei General Hospital, Asahikawa, Hokkaido, and 3Third Department of Internal Medicine, Asahikawa Medical College, Asahikawa, Japan Summary. Ultrastructural localization of myelo­ and shape (Ackerman and Clark, 1971). In general, the peroxidase (MPO) in the granules of human circulating ultrastructural localization of MPO has been performed neutrophils was examined by cryosection. On careful employing a cytochemical technique (Graham and comparison with the morphological characteristics of the Karnovksy, 1966). However, using this technique, the granules by conventional transmission electron homogeneous chemical product induced by the microscopic study, large MPO-positive granules were cytochemical reaction makes it difficult to identify divided into five types by immunocryoultramicrotomy intragranular structure. Moreover, it is not easy to using monoclonal antibody. Double staining of MPO and precisely pinpoint which granules observed by lactoferrin (or lysozyme) was also performed. Lacto­ conventional transmission electron microscopy are MPO ferrin was generally detected in MPO-negative granules. positive (MPO+). To overcome these disadvantages, an Lysozyme immunostaining was present in MPO-positive ultrastructural immunogold staining, by which the and -negative granules. These data may suggest different structure can still be observed even after positive functions among large MPO-positive granules of human reaction for detecting intragranular proteins, has been circulating neutrophils.
    [Show full text]