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Sasvari Z, Lin W, Inaba JI, Xu K, Kovalev N, Nagy PD. Co-opted Cellular Sac1 Lipid Phosphatase and PI(4)P Phosphoinositide Are Key Host Factors during the Biogenesis of the Tombusvirus Replication Compartment. J Virol 2020; 94:e01979-19. [PMID: 32269127 PMCID: PMC7307105 DOI: 10.1128/jvi.01979-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 04/02/2020] [Indexed: 12/19/2022] Open
Abstract
Positive-strand RNA [(+)RNA] viruses assemble numerous membrane-bound viral replicase complexes (VRCs) with the help of viral replication proteins and co-opted host proteins within large viral replication compartments in the cytosol of infected cells. In this study, we found that deletion or depletion of Sac1 phosphatidylinositol 4-phosphate [PI(4)P] phosphatase reduced tomato bushy stunt virus (TBSV) replication in yeast (Saccharomyces cerevisiae) and plants. We demonstrate a critical role for Sac1 in TBSV replicase assembly in a cell-free replicase reconstitution assay. The effect of Sac1 seems to be direct, based on its interaction with the TBSV p33 replication protein, its copurification with the tombusvirus replicase, and its presence in the virus-induced membrane contact sites and within the TBSV replication compartment. The proviral functions of Sac1 include manipulation of lipid composition, sterol enrichment within the VRCs, and recruitment of additional host factors into VRCs. Depletion of Sac1 inhibited the recruitment of Rab5 GTPase-positive endosomes and enrichment of phosphatidylethanolamine in the viral replication compartment. We propose that Sac1 might be a component of the assembly hub for VRCs, likely in collaboration with the co-opted the syntaxin18-like Ufe1 SNARE protein within the TBSV replication compartments. This work also led to demonstration of the enrichment of PI(4)P phosphoinositide within the replication compartment. Reduction in the PI(4)P level due to chemical inhibition in plant protoplasts; depletion of two PI(4)P kinases, Stt4p and Pik1p; or sequestration of free PI(4)P via expression of a PI(4)P-binding protein in yeast strongly inhibited TBSV replication. Altogether, Sac1 and PI(4)P play important proviral roles during TBSV replication.IMPORTANCE Replication of positive-strand RNA viruses depends on recruitment of host components into viral replication compartments or organelles. Using TBSV, we uncovered the critical roles of Sac1 PI(4)P phosphatase and its substrate, PI(4)P phosphoinositide, in promoting viral replication. Both Sac1 and PI(4)P are recruited to the site of viral replication to facilitate the assembly of the viral replicase complexes, which perform viral RNA replication. We found that Sac1 affects the recruitment of other host factors and enrichment of phosphatidylethanolamine and sterol lipids within the subverted host membranes to promote optimal viral replication. In summary, this work demonstrates the novel functions of Sac1 and PI(4)P in TBSV replication in the model host yeast and in plants.
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Affiliation(s)
- Zsuzsanna Sasvari
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Wenwu Lin
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Jun-Ichi Inaba
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Kai Xu
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Nikolay Kovalev
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
| | - Peter D Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA
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Alegre ML, Steelheart C, Baldet P, Rothan C, Just D, Okabe Y, Ezura H, Smirnoff N, Gergoff Grozeff GE, Bartoli CG. Deficiency of GDP-L-galactose phosphorylase, an enzyme required for ascorbic acid synthesis, reduces tomato fruit yield. Planta 2020; 251:54. [PMID: 31970534 DOI: 10.1007/s00425-020-03345-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 01/10/2020] [Indexed: 05/26/2023]
Abstract
Reduced GDP-L-galactose phosphorylase expression and deficiency of ascorbic acid content lead to decreased fruit set and yield in tomato plants. Reduced GDP-L-galactose phosphorylase expression and deficiency of ascorbic acid content lead to decreased fruit set and yield in tomato plants. GDP-L-galactose phosphorylase (GGP) catalyzes the first step committed to ascorbic acid synthesis. The participation of GDP-L-galactose phosphorylase and ascorbate in tomato fruit production and quality was studied in this work using two SlGGP1 deficient EMS Micro-Tom mutants. The SlGGP1 mutants display decreased concentrations of ascorbate in roots, leaves, flowers, and fruit. The initiation of anthesis is delayed in ggp1 plants but the number of flowers is similar to wild type. The number of fruits is reduced in ggp1 mutants with an increased individual weight. However, the whole fruit biomass accumulation is reduced in both mutant lines. Fruits of the ggp1 plants produce more ethylene and show higher firmness and soluble solids content than the wild type after the breaker stage. Leaf CO2 uptake decreases about 50% in both ggp1 mutants at saturating light conditions; however, O2 production in an enriched CO2 atmosphere is only 19% higher in wild type leaves. Leaf conductance that is largely reduced in both mutants may be the main limitation for photosynthesis. Sink-source assays and hormone concentration were measured to determine restrictions to fruit yield. Manipulation of leaf area/fruit number relationship demonstrates that the number of fruits and not the provision of photoassimilates from the source restricts biomass accumulation in the ggp1 lines. The lower gibberellins concentration measured in the flowers would contribute to the lower fruit set, thus impacting in tomato yield. Taken as a whole these results demonstrate that ascorbate biosynthetic pathway critically participates in tomato development and fruit production.
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Affiliation(s)
- Matías L Alegre
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Charlotte Steelheart
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Pierre Baldet
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Christophe Rothan
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Daniel Just
- UMR 1332 Biologie du Fruit Et Pathologie, Institut National de la Recherche Agronomique (INRA), Université de Bordeaux, 33140, Villenave d'Ornon, France
| | - Yoshihiro Okabe
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Hiroshi Ezura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QD, UK
| | - Gustavo E Gergoff Grozeff
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina
| | - Carlos G Bartoli
- INFIVE, Facultades de Ciencias Agrarias y Forestales y Ciencias Naturales, Universidad Nacional de La Plata-CCT CONICET, La Plata, Argentina.
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Alhaddad B, Schossig A, Haack TB, Kovács-Nagy R, Braunisch MC, Makowski C, Senderek J, Vill K, Müller-Felber W, Strom TM, Krabichler B, Freisinger P, Deshpande C, Polster T, Wolf NI, Desguerre I, Wörmann F, Rötig A, Ahting U, Kopajtich R, Prokisch H, Meitinger T, Feichtinger RG, Mayr JA, Jungbluth H, Hubmann M, Zschocke J, Distelmaier F, Koch J. PRUNE1 Deficiency: Expanding the Clinical and Genetic Spectrum. Neuropediatrics 2018; 49:330-338. [PMID: 29940663 DOI: 10.1055/s-0038-1661396] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Primary microcephaly and profound global developmental delay have been considered the core clinical phenotype in patients with bi-allelic PRUNE1 mutations. METHODS Linkage analysis and whole-exome sequencing (WES) in a multiplex family and extraction of further cases from a WES repository containing 571 children with severe developmental disabilities and neurologic symptoms. RESULTS We identified bi-allelic PRUNE1 mutations in twelve children from six unrelated families. All patients who survived beyond the first 6 months of life had early-onset global developmental delay, bilateral spastic paresis, dysphagia and difficult-to-treat seizures, while congenital or later-evolving microcephaly was not a consistent finding. Brain MRI showed variable anomalies with progressive cerebral and cerebellar atrophies and T2-hyperintense brain stem lesions. Peripheral neuropathy was documented in five cases. Disease course was progressive in all patients and eight children died in the first or early second decade of life. In addition to the previously reported missense mutation p.(Asp106Asn), we observed a novel homozygous missense variant p.(Leu172Pro) and a homozygous contiguous gene deletion encompassing most of the PRUNE1 gene and part of the neighboring BNIPL gene. CONCLUSIONS PRUNE1 deficiency causes severe early-onset disease affecting the central and peripheral nervous systems. Microcephaly is probably not a universal feature.
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Affiliation(s)
- Bader Alhaddad
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Anna Schossig
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Tobias B Haack
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Germany
| | - Reka Kovács-Nagy
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Matthias C Braunisch
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christine Makowski
- Department of Pediatrics, Technische Universität München (TUM), Munich, Germany
| | - Jan Senderek
- Department of Neurology, Friedrich Baur Institute, Ludwig Maximilians University Munich, Munich, Germany
| | - Katharina Vill
- Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Wolfgang Müller-Felber
- Department of Pediatric Neurology and Developmental Medicine, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tim M Strom
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Birgit Krabichler
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Peter Freisinger
- Department of Pediatrics, Kreisklinken Reutlingen, Reutlingen, Germany
| | - Charu Deshpande
- Department of Clinical Genetics, Guy's Hospital, London, United Kingdom
| | - Tilman Polster
- Department of Pediatric Epileptology, Bethel Epilepsy Centre, Bielefeld, Germany
| | - Nicole I Wolf
- Department of Child Neurology and Amsterdam Neuroscience, VU University Medical Centre, Amsterdam, The Netherlands
| | - Isabelle Desguerre
- Department of Pediatric Neurology, Necker Enfants Malades Hospital, Paris, France
| | - Friedrich Wörmann
- Department of Pediatric Epileptology, Bethel Epilepsy Centre, Bielefeld, Germany
| | - Agnès Rötig
- INSERM U1163, Institut Imagine, Université Paris Descartes, Paris, France
| | - Uwe Ahting
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Robert Kopajtich
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - René G Feichtinger
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Johannes A Mayr
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, United Kingdom
- Department of Basic and Clinical Neuroscience, IoPPN, King's College London, London, United Kingdom
| | - Michael Hubmann
- Department of Neuropediatrics, Kinderärzte Zirndorf, Zirndorf, Germany
| | - Johannes Zschocke
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Johannes Koch
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Salzburg, Austria
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di Salvo ML, Mastrangelo M, Nogués I, Tolve M, Paiardini A, Carducci C, Mei D, Montomoli M, Tramonti A, Guerrini R, Contestabile R, Leuzzi V. Pyridoxine-5'-phosphate oxidase (Pnpo) deficiency: Clinical and biochemical alterations associated with the C.347g>A (P.·Arg116gln) mutation. Mol Genet Metab 2017; 122:135-142. [PMID: 28818555 DOI: 10.1016/j.ymgme.2017.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/09/2017] [Accepted: 08/10/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pyridoxal-5'-phosphate oxidase (PNPO) deficiency presents as a severe neonatal encephalopathy responsive to pyridoxal-5'-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected genetic variants on PNPO gene whose pathogenic role and clinical expression remain to be established. OBJECTIVE This paper aims to characterize the functional effects of the c.347G>A (p.Arg116Gln) mutation in the PNPO gene in order to define its pathogenicity and describe the clinical features of new patients with epilepsy carrying this mutation. METHODS Arg116Gln protein variant was expressed as recombinant protein. The mutant protein was characterized with respect to structural and kinetic properties, thermal stability, binding constants of cofactor (FMN) and product (PLP). We also reviewed clinical data of 3 new patients carrying the mutation. RESULTS The Arg116Gln mutation does not alter the overall enzyme structure and only slightly affects its catalytic efficiency; nevertheless, this mutation affects thermal stability of PNPO, reduces its affinity for FMN and impairs transfer of PLP to PLP-dependent enzymes. Three boys with seizure onset between 8months and 3years of age, carrying the Arg116Gln mutation, are described. These three patients exhibited different seizure types associated with interictal EEG abnormalities and slow background activity. Mild/moderate intellectual disability was observed in 2/3 patients. A dramatic therapeutic response to pyridoxine was observed in the only patient who still had active seizures when starting treatment, while in all three patients interictal EEG discharges and background activity improved after pyridoxine treatment was initiated. CONCLUSIONS The reported data support a pathogenic role of the c.347G>A (p.Arg116Gln) mutation in PNPO deficiency. The later onset of symptoms and the milder epilepsy phenotype of these expand the disease phenotype.
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Affiliation(s)
- Martino L di Salvo
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Italy.
| | - Mario Mastrangelo
- Dipartimento di Pediatria e Neuropsichiatria Infantile, Sapienza Università di Roma, Italy.
| | - Isabel Nogués
- Istituto di Biologia Ambientale e Forestale, Consiglio Nazionale delle Ricerche, Monterotondo Scalo, Roma, Italy.
| | - Manuela Tolve
- Dipartimento di Medicina Sperimentale, Sapienza Università di Roma, Italy
| | - Alessandro Paiardini
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma, Italy.
| | - Carla Carducci
- Dipartimento di Medicina Sperimentale, Sapienza Università di Roma, Italy.
| | - Davide Mei
- Dipartimento di Neuroscienze, Azienda Ospedaliero-Universitaria Meyer, Università di Firenze, Italy.
| | - Martino Montomoli
- Dipartimento di Neuroscienze, Azienda Ospedaliero-Universitaria Meyer, Università di Firenze, Italy.
| | - Angela Tramonti
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy.
| | - Renzo Guerrini
- Dipartimento di Neuroscienze, Azienda Ospedaliero-Universitaria Meyer, Università di Firenze, Italy.
| | - Roberto Contestabile
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Italy.
| | - Vincenzo Leuzzi
- Dipartimento di Pediatria e Neuropsichiatria Infantile, Sapienza Università di Roma, Italy.
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5
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Evans MD, Mistry V, Singh R, Gackowski D, Różalski R, Siomek-Gorecka A, Phillips DH, Zuo J, Mullenders L, Pines A, Nakabeppu Y, Sakumi K, Sekiguchi M, Tsuzuki T, Bignami M, Oliński R, Cooke MS. Nucleotide excision repair of oxidised genomic DNA is not a source of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine. Free Radic Biol Med 2016; 99:385-391. [PMID: 27585947 DOI: 10.1016/j.freeradbiomed.2016.08.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/09/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
Abstract
Urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is a widely measured biomarker of oxidative stress. It has been commonly assumed to be a product of DNA repair, and therefore reflective of DNA oxidation. However, the source of urinary 8-oxodGuo is not understood, although potential confounding contributions from cell turnover and diet have been ruled out. Clearly it is critical to understand the precise biological origins of this important biomarker, so that the target molecule that is oxidised can be identified, and the significance of its excretion can be interpreted fully. In the present study we aimed to assess the contributions of nucleotide excision repair (NER), by both the global genome NER (GG-NER) and transcription-coupled NER (TC-NER) pathways, and sanitisation of the dGTP pool (e.g. via the activity of the MTH1 protein), on the production of 8-oxodGuo, using selected genetically-modified mice. In xeroderma pigmentosum A (XPA) mice, in which GG-NER and TC-NER are both defective, the urinary 8-oxodGuo data were unequivocal in ruling out a contribution from NER. In line with the XPA data, the production of urinary 8-oxodGuo was not affected in the xeroderma pigmentosum C mice, specifically excluding a role of the GG-NER pathway. The bulk of the literature supports the mechanism that the NER proteins are responsible for removing damage to the transcribed strand of DNA via TC-NER, and on this basis we also examined Cockayne Syndrome mice, which have a functional loss of TC-NER. These mice showed no difference in urinary 8-oxodGuo excretion, compared to wild type, demonstrating that TC-NER does not contribute to urinary 8-oxodGuo levels. These findings call into question whether genomic DNA is the primary source of urinary 8-oxodGuo, which would largely exclude it as a biomarker of DNA oxidation. The urinary 8-oxodGuo levels from the MTH1 mice (both knock-out and hMTH1-Tg) were not significantly different to the wild-type mice. We suggest that these findings are due to redundancy in the process, and that other enzymes substitute for the lack of MTH1, however the present study cannot determine whether or not the 2'-deoxyribonucleotide pool is the source of urinary 8-oxodGuo. On the basis of the above, urinary 8-oxodGuo is most accurately defined as a non-invasive biomarker of oxidative stress, derived from oxidatively generated damage to 2'-deoxyguanosine.
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Affiliation(s)
- Mark D Evans
- Oxidative Stress Group, University of Leicester, Leicester, United Kingdom.
| | - Vilas Mistry
- Oxidative Stress Group, University of Leicester, Leicester, United Kingdom
| | - Rajinder Singh
- Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester, United Kingdom
| | - Daniel Gackowski
- Department of Clinical Biochemistry, Faculty of Pharmacy, Ludwik Rydygier Collegium Medicum, Bydgoszcz, and Nicolaus Copernicus University in Toruń, Poland
| | - Rafał Różalski
- Department of Clinical Biochemistry, Faculty of Pharmacy, Ludwik Rydygier Collegium Medicum, Bydgoszcz, and Nicolaus Copernicus University in Toruń, Poland
| | - Agnieszka Siomek-Gorecka
- Department of Clinical Biochemistry, Faculty of Pharmacy, Ludwik Rydygier Collegium Medicum, Bydgoszcz, and Nicolaus Copernicus University in Toruń, Poland
| | - David H Phillips
- Section of Molecular Carcinogenesis, Institute of Cancer Research, Sutton, Surrey, United Kingdom
| | - Jie Zuo
- Section of Molecular Carcinogenesis, Institute of Cancer Research, Sutton, Surrey, United Kingdom
| | - Leon Mullenders
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Alex Pines
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Kunihiko Sakumi
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | | | - Teruhisa Tsuzuki
- Department of Medical Biophysics and Radiation Biology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Margherita Bignami
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Ryszard Oliński
- Department of Clinical Biochemistry, Faculty of Pharmacy, Ludwik Rydygier Collegium Medicum, Bydgoszcz, and Nicolaus Copernicus University in Toruń, Poland
| | - Marcus S Cooke
- Oxidative Stress Group, University of Leicester, Leicester, United Kingdom; Department of Genetics, University of Leicester, United Kingdom.
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6
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Ji L, Kim NH, Huh SO, Rhee HJ. Depletion of Inositol Polyphosphate 4-Phosphatase II Suppresses Callosal Axon Formation in the Developing Mice. Mol Cells 2016; 39:501-7. [PMID: 27109423 PMCID: PMC4916402 DOI: 10.14348/molcells.2016.0058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 02/02/2023] Open
Abstract
The corpus callosum is a bundle of nerve fibers that connects the two cerebral hemispheres and is essential for coordinated transmission of information between them. Disruption of early stages of callosal development can cause agenesis of the corpus callosum (AgCC), including both complete and partial callosal absence, causing mild to severe cognitive impairment. Despite extensive studies, the etiology of AgCC remains to be clarified due to the complicated mechanism involved in generating AgCC. The biological function of PI3K signaling including phosphatidylinositol-3,4,5-trisphosphate is well established in diverse biochemical processes including axon and dendrite morphogenesis, but the function of the closely related phosphatidylinositol-3,4,-bisphosphate (PI(3,4)P2) signaling, particularly in the nervous system, is largely unknown. Here, we provide the first report on the role of inositol polyphosphate 4-phosphatase II (INPP4B), a PI(3,4)P2 metabolizing 4-phosphatase in the regulation of callosal axon formation. Depleting INPP4B by in utero electroporation suppressed medially directed callosal axon formation. Moreover, depletion of INPP4B significantly attenuated formation of Satb2-positive pyramidal neurons and axon polarization in cortical neurons during cortical development. Taken together, these data suggest that INPP4B plays a role in the regulating callosal axon formation by controlling axon polarization and the Satb2-positive pyramidal neuron population. Dysregulation of INPP4B during cortical development may be implicated in the generation of partial AgCC.
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Affiliation(s)
- Liting Ji
- Department of Pharmacology, College of Medicine, Hallym University, Chunchon 200-702,
Korea
| | - Nam-Ho Kim
- Department of Pharmacology, College of Medicine, Hallym University, Chunchon 200-702,
Korea
| | - Sung-Oh Huh
- Department of Pharmacology, College of Medicine, Hallym University, Chunchon 200-702,
Korea
- Institute of Natural Medicine, Hallym University, Chunchon 200-702,
Korea
| | - Hae Jin Rhee
- Institute of Natural Medicine, Hallym University, Chunchon 200-702,
Korea
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7
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Marriott AS, Vasieva O, Fang Y, Copeland NA, McLennan AG, Jones NJ. NUDT2 Disruption Elevates Diadenosine Tetraphosphate (Ap4A) and Down-Regulates Immune Response and Cancer Promotion Genes. PLoS One 2016; 11:e0154674. [PMID: 27144453 PMCID: PMC4856261 DOI: 10.1371/journal.pone.0154674] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/18/2016] [Indexed: 01/04/2023] Open
Abstract
Regulation of gene expression is one of several roles proposed for the stress-induced nucleotide diadenosine tetraphosphate (Ap4A). We have examined this directly by a comparative RNA-Seq analysis of KBM-7 chronic myelogenous leukemia cells and KBM-7 cells in which the NUDT2 Ap4A hydrolase gene had been disrupted (NuKO cells), causing a 175-fold increase in intracellular Ap4A. 6,288 differentially expressed genes were identified with P < 0.05. Of these, 980 were up-regulated and 705 down-regulated in NuKO cells with a fold-change ≥ 2. Ingenuity® Pathway Analysis (IPA®) was used to assign these genes to known canonical pathways and functional networks. Pathways associated with interferon responses, pattern recognition receptors and inflammation scored highly in the down-regulated set of genes while functions associated with MHC class II antigens were prominent among the up-regulated genes, which otherwise showed little organization into major functional gene sets. Tryptophan catabolism was also strongly down-regulated as were numerous genes known to be involved in tumor promotion in other systems, with roles in the epithelial-mesenchymal transition, proliferation, invasion and metastasis. Conversely, some pro-apoptotic genes were up-regulated. Major upstream factors predicted by IPA® for gene down-regulation included NFκB, STAT1/2, IRF3/4 and SP1 but no major factors controlling gene up-regulation were identified. Potential mechanisms for gene regulation mediated by Ap4A and/or NUDT2 disruption include binding of Ap4A to the HINT1 co-repressor, autocrine activation of purinoceptors by Ap4A, chromatin remodeling, effects of NUDT2 loss on transcript stability, and inhibition of ATP-dependent regulatory factors such as protein kinases by Ap4A. Existing evidence favors the last of these as the most probable mechanism. Regardless, our results suggest that the NUDT2 protein could be a novel cancer chemotherapeutic target, with its inhibition potentially exerting strong anti-tumor effects via multiple pathways involving metastasis, invasion, immunosuppression and apoptosis.
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MESH Headings
- Cell Line, Tumor
- Dinucleoside Phosphates/metabolism
- Down-Regulation
- Gene Expression Profiling
- Gene Knockout Techniques
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/immunology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Phosphoric Monoester Hydrolases/deficiency
- Phosphoric Monoester Hydrolases/genetics
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Affiliation(s)
- Andrew S. Marriott
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Olga Vasieva
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Yongxiang Fang
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Nikki A. Copeland
- Division of Biomedical and Life Sciences, University of Lancaster, Lancaster, Lancashire, United Kingdom
| | - Alexander G. McLennan
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail: (AGM); (NJJ)
| | - Nigel J. Jones
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail: (AGM); (NJJ)
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8
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Javaheri B, Carriero A, Staines KA, Chang YM, Houston DA, Oldknow KJ, Millan JL, Kazeruni BN, Salmon P, Shefelbine S, Farquharson C, Pitsillides AA. Phospho1 deficiency transiently modifies bone architecture yet produces consistent modification in osteocyte differentiation and vascular porosity with ageing. Bone 2015; 81:277-291. [PMID: 26232374 PMCID: PMC4652607 DOI: 10.1016/j.bone.2015.07.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/24/2015] [Accepted: 07/27/2015] [Indexed: 12/11/2022]
Abstract
PHOSPHO1 is one of principal proteins involved in initiating bone matrix mineralisation. Recent studies have found that Phospho1 KO mice (Phospho1-R74X) display multiple skeletal abnormalities with spontaneous fractures, bowed long bones, osteomalacia and scoliosis. These analyses have however been limited to young mice and it remains unclear whether the role of PHOSPHO1 is conserved in the mature murine skeleton where bone turnover is limited. In this study, we have used ex-vivo computerised tomography to examine the effect of Phospho1 deletion on tibial bone architecture in mice at a range of ages (5, 7, 16 and 34 weeks of age) to establish whether its role is conserved during skeletal growth and maturation. Matrix mineralisation has also been reported to influence terminal osteoblast differentiation into osteocytes and we have also explored whether hypomineralised bones in Phospho1 KO mice exhibit modified osteocyte lacunar and vascular porosity. Our data reveal that Phospho1 deficiency generates age-related defects in trabecular architecture and compromised cortical microarchitecture with greater porosity accompanied by marked alterations in osteocyte shape, significant increases in osteocytic lacuna and vessel number. Our in vitro studies examining the behaviour of osteoblast derived from Phospho1 KO and wild-type mice reveal reduced levels of matrix mineralisation and modified osteocytogenic programming in cells deficient in PHOSPHO1. Together our data suggest that deficiency in PHOSPHO1 exerts modifications in bone architecture that are transient and depend upon age, yet produces consistent modification in lacunar and vascular porosity. It is possible that the inhibitory role of PHOSPHO1 on osteocyte differentiation leads to these age-related changes in bone architecture. It is also intriguing to note that this apparent acceleration in osteocyte differentiation evident in the hypomineralised bones of Phospho1 KO mice suggests an uncoupling of the interplay between osteocytogenesis and biomineralisation. Further studies are required to dissect the molecular processes underlying the regulatory influences exerted by PHOSPHO1 on the skeleton with ageing.
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Affiliation(s)
- B Javaheri
- The Royal Veterinary College, London, United Kingdom.
| | - A Carriero
- Department of Biomedical Engineering, Florida Institute of Technology Melbourne, FL 32901, USA
| | - K A Staines
- The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh, United Kingdom
| | - Y-M Chang
- The Royal Veterinary College, London, United Kingdom
| | - D A Houston
- The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh, United Kingdom
| | - K J Oldknow
- The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh, United Kingdom
| | - J L Millan
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | | | - P Salmon
- Bruker-microCT, Kartuizersweg 3B, 2550 Kontich, Belgium
| | - S Shefelbine
- Department of Mechanical and Industrial Engineering, Northeastern University, USA
| | - C Farquharson
- The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh, United Kingdom
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9
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Mager LF, Riether C, Schürch CM, Banz Y, Wasmer MH, Stuber R, Theocharides AP, Li X, Xia Y, Saito H, Nakae S, Baerlocher GM, Manz MG, McCoy KD, Macpherson AJ, Ochsenbein AF, Beutler B, Krebs P. IL-33 signaling contributes to the pathogenesis of myeloproliferative neoplasms. J Clin Invest 2015; 125:2579-91. [PMID: 26011644 DOI: 10.1172/jci77347] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/23/2015] [Indexed: 12/16/2022] Open
Abstract
Myeloproliferative neoplasms (MPNs) are characterized by the clonal expansion of one or more myeloid cell lineage. In most cases, proliferation of the malignant clone is ascribed to defined genetic alterations. MPNs are also associated with aberrant expression and activity of multiple cytokines; however, the mechanisms by which these cytokines contribute to disease pathogenesis are poorly understood. Here, we reveal a non-redundant role for steady-state IL-33 in supporting dysregulated myelopoiesis in a murine model of MPN. Genetic ablation of the IL-33 signaling pathway was sufficient and necessary to restore normal hematopoiesis and abrogate MPN-like disease in animals lacking the inositol phosphatase SHIP. Stromal cell-derived IL-33 stimulated the secretion of cytokines and growth factors by myeloid and non-hematopoietic cells of the BM, resulting in myeloproliferation in SHIP-deficient animals. Additionally, in the transgenic JAK2V617F model, the onset of MPN was delayed in animals lacking IL-33 in radio-resistant cells. In human BM, we detected increased numbers of IL-33-expressing cells, specifically in biopsies from MPN patients. Exogenous IL-33 promoted cytokine production and colony formation by primary CD34+ MPN stem/progenitor cells from patients. Moreover, IL-33 improved the survival of JAK2V617F-positive cell lines. Together, these data indicate a central role for IL-33 signaling in the pathogenesis of MPNs.
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10
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Ip LRH, Poulogiannis G, Viciano FC, Sasaki J, Kofuji S, Spanswick VJ, Hochhauser D, Hartley JA, Sasaki T, Gewinner CA. Loss of INPP4B causes a DNA repair defect through loss of BRCA1, ATM and ATR and can be targeted with PARP inhibitor treatment. Oncotarget 2015; 6:10548-62. [PMID: 25868852 PMCID: PMC4496374 DOI: 10.18632/oncotarget.3307] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 02/08/2015] [Indexed: 12/18/2022] Open
Abstract
Treatment options for ovarian cancer patients remain limited and overall survival is less than 50% despite recent clinical advances. The lipid phosphatase inositol polyphosphate 4-phosphatase type II (INPP4B) has been described as a tumor suppressor in the PI3K/Akt pathway with loss of expression found most pronounced in breast, ovarian cancer and melanoma. Using microarray technology we identified a DNA repair defect in INPP4B-deficient cells, which we further characterized by comet assays and quantification of γH2AX, RAD51 and 53BP1 foci formation. INPP4B loss resulted in significantly increased sensitivity towards PARP inhibition, comparable to loss of BRCA1 in two- and three-dimensional in vitro models, as well as in in vivo xenograft models. Mechanistically, we discovered that INPP4B forms a protein complex with the key players of DNA repair, ATR and BRCA1, in GST pulldown and 293T overexpression assays, and INPP4B loss affects BRCA1, ATM and ATR protein stability resulting in the observed DNA repair defect. Given that INPP4B loss has been found in 40% of ovarian cancer patients, this study provides the rationale for establishing INPP4B as a biomarker of PARP inhibitor response, and consequently offers novel therapeutic options for a significant subset of patients. Loss of the tumor suppressor inositol polyphosphate 4-phosphatase type II (INPP4B) results in a DNA repair defect due to concomitant loss of BRCA1, ATR and ATM and can be therapeutically targeted with PARP inhibitors.
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Affiliation(s)
- Laura R H Ip
- Department of Cancer Biology, UCL Cancer Institute, University College London, London, UK
| | - George Poulogiannis
- The Institute of Cancer Research, Signalling and Cancer Metabolism, London, UK
| | - Felipe Cia Viciano
- Department of Cancer Biology, UCL Cancer Institute, University College London, London, UK
- Faculty of Infectious and Tropical Diseases, Immunology and Infection Department, London School of Hygiene & Tropical Diseases, London, UK
| | - Junko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Satoshi Kofuji
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Victoria J Spanswick
- Cancer Research UK Drug-DNA Interaction Research Group, UCL Cancer Institute, University College London, London, UK
| | - Daniel Hochhauser
- Cancer Research UK Drug-DNA Interaction Research Group, UCL Cancer Institute, University College London, London, UK
| | - John A Hartley
- Cancer Research UK Drug-DNA Interaction Research Group, UCL Cancer Institute, University College London, London, UK
| | - Takehiko Sasaki
- Department of Medical Biology, Akita University School of Medicine, Akita, Japan
| | - Christina A Gewinner
- Department of Cancer Biology, UCL Cancer Institute, University College London, London, UK
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11
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Chauhan P, Reddy PV, Singh R, Jaisinghani N, Gandotra S, Tyagi AK. Secretory phosphatases deficient mutant of Mycobacterium tuberculosis imparts protection at the primary site of infection in guinea pigs. PLoS One 2013; 8:e77930. [PMID: 24205032 PMCID: PMC3799640 DOI: 10.1371/journal.pone.0077930] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 09/06/2013] [Indexed: 12/20/2022] Open
Abstract
Background The failure of Mycobacterium bovis Bacille Calmette-Guérin to impart satisfactory protection against adult pulmonary tuberculosis has necessitated the development of more effective TB vaccines. The assumption that the vaccine strain should be antigenically as similar as possible to the disease causing pathogen has led to the evaluation of M.tuberculosis mutants as candidate tuberculosis vaccines. Methods/Principal Findings In this study, we have generated a mutant of M.tuberculosis (Mtb∆mms) by disrupting 3 virulence genes encoding a mycobacterial secretory acid phosphatase (sapM) and two phosphotyrosine protein phosphatases (mptpA and mptpB) and have evaluated its protective efficacy in guinea pigs. We observed that Mtb∆mms was highly attenuated in THP-1 macrophages. Moreover, no bacilli were recovered from the lungs and spleens of guinea pigs after 10 weeks of Mtb∆mms inoculation, although, initially, the mutant exhibited some growth in the spleens. Subsequently, when Mtb∆mms was evaluated for its protective efficacy, we observed that similar to BCG vaccination, Mtb∆mms exhibited a significantly reduced CFU in the lungs of guinea pigs when compared with the unvaccinated animals at 4 weeks after challenge. In addition, our observations at 12 weeks post challenge demonstrated that Mtb∆mms exhibited a more sustainable and superior protection in lungs as compared to BCG. However, the mutant failed to control the hematogenous spread as the splenic bacillary load between Mtb∆mms vaccinated and sham immunized animals was not significantly different. The gross pathological observations and histopathological observations corroborated the bacterial findings. Inspite of disruption of phosphatase genes in MtbΔmms, the lipid profiles of M.tuberculosis and MtbΔmms were identical indicating thereby that the phenotype of the mutant was ascribed to the loss of phosphatase genes and the influence was not related to any alteration in the lipid composition. Conclusions/Significance This study highlights the importance of M.tuberculosis mutants in imparting protection against pulmonary TB.
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Affiliation(s)
- Priyanka Chauhan
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - P. Vineel Reddy
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Ramandeep Singh
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | | | - Sheetal Gandotra
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Anil K. Tyagi
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
- ∗ E-mail:
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12
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van der Crabben SN, Verhoeven-Duif NM, Brilstra EH, Van Maldergem L, Coskun T, Rubio-Gozalbo E, Berger R, de Koning TJ. An update on serine deficiency disorders. J Inherit Metab Dis 2013; 36:613-9. [PMID: 23463425 DOI: 10.1007/s10545-013-9592-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 01/17/2013] [Accepted: 01/21/2013] [Indexed: 11/28/2022]
Abstract
Serine deficiency disorders are caused by a defect in one of the three synthesising enzymes of the L-serine biosynthesis pathway. Serine deficiency disorders give rise to a neurological phenotype with psychomotor retardation, microcephaly and seizures in newborns and children or progressive polyneuropathy in adult patients. There are three defects that cause serine deficiency of which 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency, the defect affecting the first step in the pathway, has been reported most frequently. The other two disorders in L-serine biosynthesis phosphoserine aminotransferase (PSAT) deficiency and phosphoserine phosphatase (PSP) deficiency have been reported only in a limited number of patients. The biochemical hallmarks of all three disorders are low concentrations of serine in cerebrospinal fluid and plasma. Prompt recognition of affected patients is important, since serine deficiency disorders are treatable causes of neurometabolic disorders. The use of age-related reference values for serine in CSF and plasma can be of great help in establishing a correct diagnosis of serine deficiency, in particular in newborns and young children.
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Affiliation(s)
- S N van der Crabben
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
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13
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Wang LY, Li D, Deng YS, Lv W, Meng QW. Antisense-mediated depletion of tomato GDP-L-galactose phosphorylase increases susceptibility to chilling stress. J Plant Physiol 2013; 170:303-14. [PMID: 23267461 DOI: 10.1016/j.jplph.2012.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 05/10/2023]
Abstract
The GDP-L-galactose phosphorylase (GGP), which converts GDP-l-galactose to l-Gal-1-phosphate, is generally considered to be a key enzyme of the major ascorbate biosynthesis pathways in higher plants, but experimental evidence for its role in tomato is lacking. In the present study, the GGP gene was isolated from tomato (Solanum lycopersicum) and transient expression of SlGGP-GFP (green fluorescent protein) fusion protein in onion cells revealed the cytoplasmic and nucleus localization of the protein. Antisense transgenic tomato lines with only 50-75% ascorbate level of the wild type (WT) were obtained. Chilling treatment induced lower increase in AsA levels and redox ratio of ascorbate in antisense transgenic plants compared with WT plants. Under chilling stress, transgenic plants accumulated more malendialdehyde (MDA) and more O(2)(·-), leaked more electrolytes and showed lower maximal photochemical efficiency of PSII (Fv/Fm), net photosynthetic rate (Pn), and oxidizable P700 compared with WT plants. Furthermore, the antisense transgenic plants exhibited significantly higher H(2)O(2) level and lower ascorbate peroxidase (APX) activity. Our results suggested that GGP plays an important role in protecting plants against chilling stress by maintaining ascorbate pool and ascorbate redox state.
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Affiliation(s)
- Li-Yan Wang
- College of Life Science, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018, PR China
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14
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Abstract
Inflammatory diseases of the mucosal surfaces are rising worldwide and particularly in the Western world that is witnessing unprecedented increases in the number and incidence of both asthma and inflammatory bowel disease. The laboratory mouse allows the application of the full panoply of modern genetic, immunological and biochemical tools to increase our understanding of how inflammation arises and how it might be controlled at mucosal surfaces. Here we provide a detailed description of how to systematically assess inflammatory disease in the lung and intestines of the laboratory mouse. We provide histopathology examples from SHIP mutant mice that are the only known genetic mutant to suffer from pulmonary consolidation, asthma, and Crohn's disease. The intent of this chapter is to facilitate increased surveillance of mucosal inflammation in studies where the laboratory mouse is utilized so that we can better understand the cell types, genes, and microorganisms that contribute to mucosal inflammatory disease and thereby develop more effective therapies and preventive strategies.
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Affiliation(s)
- R W Engelman
- Department of Pathology, Lee Moffitt Comprehensive Cancer Center and Research Institute, University of South Florida, Tampa, FL, USA
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15
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Kiffer-Moreira T, Yadav MC, Zhu D, Narisawa S, Sheen C, Stec B, Cosford ND, Dahl R, Farquharson C, Hoylaerts MF, MacRae VE, Millán JL. Pharmacological inhibition of PHOSPHO1 suppresses vascular smooth muscle cell calcification. J Bone Miner Res 2013; 28:81-91. [PMID: 22887744 PMCID: PMC3562655 DOI: 10.1002/jbmr.1733] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 07/20/2012] [Accepted: 07/30/2012] [Indexed: 11/09/2022]
Abstract
Medial vascular calcification (MVC) is common in patients with chronic kidney disease, obesity, and aging. MVC is an actively regulated process that resembles skeletal mineralization, resulting from chondro-osteogenic transformation of vascular smooth muscle cells (VSMCs). Here, we used mineralizing murine VSMCs to study the expression of PHOSPHO1, a phosphatase that participates in the first step of matrix vesicles-mediated initiation of mineralization during endochondral ossification. Wild-type (WT) VSMCs cultured under calcifying conditions exhibited increased Phospho1 gene expression and Phospho1(-/-) VSMCs failed to mineralize in vitro. Using natural PHOSPHO1 substrates, potent and specific inhibitors of PHOSPHO1 were identified via high-throughput screening and mechanistic analysis and two of these inhibitors, designated MLS-0390838 and MLS-0263839, were selected for further analysis. Their effectiveness in preventing VSMC calcification by targeting PHOSPHO1 function was assessed, alone and in combination with a potent tissue-nonspecific alkaline phosphatase (TNAP) inhibitor MLS-0038949. PHOSPHO1 inhibition by MLS-0263839 in mineralizing WT cells (cultured with added inorganic phosphate) reduced calcification in culture to 41.8% ± 2.0% of control. Combined inhibition of PHOSPHO1 by MLS-0263839 and TNAP by MLS-0038949 significantly reduced calcification to 20.9% ± 0.74% of control. Furthermore, the dual inhibition strategy affected the expression of several mineralization-related enzymes while increasing expression of the smooth muscle cell marker Acta2. We conclude that PHOSPHO1 plays a critical role in VSMC mineralization and that "phosphatase inhibition" may be a useful therapeutic strategy to reduce MVC.
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Affiliation(s)
- Tina Kiffer-Moreira
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Manisha C Yadav
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Dongxing Zhu
- The Roslin Institute, The University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, Scotland, UK
| | - Sonoko Narisawa
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Campbell Sheen
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Boguslaw Stec
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
| | - Nicholas D. Cosford
- Conrad Prebys Center for Chemical Genomics, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Russell Dahl
- Conrad Prebys Center for Chemical Genomics, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Colin Farquharson
- The Roslin Institute, The University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, Scotland, UK
| | - Marc. F. Hoylaerts
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Vicky E. MacRae
- The Roslin Institute, The University of Edinburgh, Easter Bush, Roslin, Midlothian, EH25 9RG, Scotland, UK
| | - José Luis Millán
- Sanford Children’s Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, USA
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16
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Timm S, Mielewczik M, Florian A, Frankenbach S, Dreissen A, Hocken N, Fernie AR, Walter A, Bauwe H. High-to-low CO2 acclimation reveals plasticity of the photorespiratory pathway and indicates regulatory links to cellular metabolism of Arabidopsis. PLoS One 2012; 7:e42809. [PMID: 22912743 PMCID: PMC3422345 DOI: 10.1371/journal.pone.0042809] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 07/12/2012] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Photorespiratory carbon metabolism was long considered as an essentially closed and nonregulated pathway with little interaction to other metabolic routes except nitrogen metabolism and respiration. Most mutants of this pathway cannot survive in ambient air and require CO(2)-enriched air for normal growth. Several studies indicate that this CO(2) requirement is very different for individual mutants, suggesting a higher plasticity and more interaction of photorespiratory metabolism as generally thought. To understand this better, we examined a variety of high- and low-level parameters at 1% CO(2) and their alteration during acclimation of wild-type plants and selected photorespiratory mutants to ambient air. METHODOLOGY AND PRINCIPAL FINDINGS The wild type and four photorespiratory mutants of Arabidopsis thaliana (Arabidopsis) were grown to a defined stadium at 1% CO(2) and then transferred to normal air (0.038% CO(2)). All other conditions remained unchanged. This approach allowed unbiased side-by-side monitoring of acclimation processes on several levels. For all lines, diel (24 h) leaf growth, photosynthetic gas exchange, and PSII fluorescence were monitored. Metabolite profiling was performed for the wild type and two mutants. During acclimation, considerable variation between the individual genotypes was detected in many of the examined parameters, which correlated with the position of the impaired reaction in the photorespiratory pathway. CONCLUSIONS Photorespiratory carbon metabolism does not operate as a fully closed pathway. Acclimation from high to low CO(2) was typically steady and consistent for a number of features over several days, but we also found unexpected short-term events, such as an intermittent very massive rise of glycine levels after transition of one particular mutant to ambient air. We conclude that photorespiration is possibly exposed to redox regulation beyond known substrate-level effects. Additionally, our data support the view that 2-phosphoglycolate could be a key regulator of photosynthetic-photorespiratory metabolism as a whole.
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Affiliation(s)
- Stefan Timm
- University of Rostock, Department of Plant Physiology, Rostock, Germany
| | - Michael Mielewczik
- Institute of Agricultural Sciences, ETH Zürich, Zürich, Switzerland
- Institute of Bio- and Geosciences IBG-2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Alexandra Florian
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Silja Frankenbach
- University of Rostock, Department of Plant Physiology, Rostock, Germany
| | - Anne Dreissen
- Institute of Bio- and Geosciences IBG-2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Nadine Hocken
- Institute of Bio- and Geosciences IBG-2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Alisdair R. Fernie
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Achim Walter
- Institute of Agricultural Sciences, ETH Zürich, Zürich, Switzerland
- Institute of Bio- and Geosciences IBG-2, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Hermann Bauwe
- University of Rostock, Department of Plant Physiology, Rostock, Germany
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18
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Huesa C, Yadav MC, Finnilä MA, Goodyear SR, Robins SP, Tanner KE, Aspden RM, Millán JL, Farquharson C. PHOSPHO1 is essential for mechanically competent mineralization and the avoidance of spontaneous fractures. Bone 2011; 48:1066-74. [PMID: 21272676 PMCID: PMC3078982 DOI: 10.1016/j.bone.2011.01.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 01/12/2011] [Accepted: 01/12/2011] [Indexed: 11/20/2022]
Abstract
Phosphatases are essential for the mineralization of the extracellular matrix within the skeleton. Their precise identities and functions however remain unclear. PHOSPHO1 is a phosphoethanolamine/phosphocholine phosphatase involved in the generation of inorganic phosphate for bone mineralization. It is highly expressed at sites of mineralization in bone and cartilage. The bones of Phospho1(-/-) mice are hypomineralized, bowed and present with spontaneous greenstick fractures at birth. In this study we show that PHOSPHO1 is essential for mechanically competent mineralization that is able to withstand habitual load. Long bones from Phospho1(-/-) mice did not fracture during 3-point bending but deformed plastically. With dynamic loading nanoindentation the elastic modulus and hardness of Phospho1(-/-) tibiae were significantly lower than wild-type tibia. Raman microscopy revealed significantly lower mineral:matrix ratios and lower carbonate substitutions in Phospho1(-/-) tibia. The altered dihydroxylysinonorleucine/hydroxylysinonorleucine and pyridinoline/deoxypyridinoline collagen crosslink ratios indicated possible changes in lysyl hydroxylase-1 activity and/or bone mineralization status. The bone formation and resorption markers, N-terminal propeptide and C-terminal telopeptide of Type I collagen, were both increased in Phospho1(-/-) mice and this we associated with increased bone remodeling during fracture repair or an attempt to remodel a mechanically competent bone capable of withstanding physiological load. In summary these data indicate that Phospho1(-/-) bones are hypomineralized and, consequently, are softer and more flexible. An inability to withstand physiological loading may explain the deformations noted. We hypothesize that this phenotype is due to the reduced availability of inorganic phosphate to form hydroxyapatite during mineralization, creating an undermineralized yet active bone.
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Affiliation(s)
- Carmen Huesa
- Bone Biology Group, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Manisha C. Yadav
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research institute, La Jolla, CA, USA
| | - Mikko A.J. Finnilä
- Department of Mechanical Engineering, Materials, University of Glasgow, Glasgow, UK
- Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu, Finland
| | - Simon R. Goodyear
- Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen, UK
| | - Simon P. Robins
- Matrix Biochemistry Group, Rowett Research Institute of Health and Nutrition, University of Aberdeen, Aberdeen, UK
| | - K. Elizabeth Tanner
- Department of Mechanical Engineering, Materials, University of Glasgow, Glasgow, UK
| | - Richard M. Aspden
- Institute of Medical Sciences, Foresterhill, University of Aberdeen, Aberdeen, UK
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research institute, La Jolla, CA, USA
| | - Colin Farquharson
- Bone Biology Group, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
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Hodgson MC, Shao LJ, Frolov A, Li R, Peterson LE, Ayala G, Ittmann MM, Weigel NL, Agoulnik IU. Decreased expression and androgen regulation of the tumor suppressor gene INPP4B in prostate cancer. Cancer Res 2011; 71:572-82. [PMID: 21224358 DOI: 10.1158/0008-5472.can-10-2314] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Patients with metastatic prostate cancer who undergo androgen-ablation therapy invariably relapse and develop incurable castration-resistant disease. Activation of the prosurvival Akt pathway accompanies androgen ablation. We discovered that the androgen receptor induces the expression of the tumor suppressor inositol polyphosphate 4-phosphatase type II (INPP4B) but not PTEN in prostate cancer cells. Optimal induction of INPP4B by an androgen receptor required the expression of the transcriptional coactivator NCoR. INPP4B dephosphorylates phosphatidylinositol-3, 4-bisphosphate, which leads to reduced phosphorylation and activity of Akt. In support of a key role for INPP4B in Akt control, INPP4B depletion activated Akt and increased cellular proliferation. The clinical significance of INPP4B in androgen-dependent prostate cancers was determined in normal or primary tumor prostate tissues derived from radical prostatectomy specimens. In primary tumors, the expression of both INPP4B and PTEN was substantially reduced compared with normal tissue. Further, the decreased expression of INPP4B reduced the time to biochemical recurrence. Thus, androgen ablation can activate the Akt pathway via INPP4B downregulation, thereby mitigating the antitumor effects of androgen ablation. Our findings reinforce the concept that patients undergoing androgen ablation may benefit from Akt-targeting therapies.
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20
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Tabatabaie L, Klomp LW, Berger R, de Koning TJ. L-serine synthesis in the central nervous system: a review on serine deficiency disorders. Mol Genet Metab 2010; 99:256-62. [PMID: 19963421 DOI: 10.1016/j.ymgme.2009.10.012] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/16/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
Abstract
The de novo synthesis of the amino acid L-serine plays an essential role in the development and functioning of the central nervous system (CNS). L-serine displays many metabolic functions during different developmental stages; among its functions providing precursors for amino acids, protein synthesis, nucleotide synthesis, neurotransmitter synthesis and L-serine derived lipids. Patients with congenital defects in the L-serine synthesizing enzymes present with severe neurological abnormalities and underscore the importance of this synthetic pathway. In this review, we will discuss the cellular functions of the L-serine pathway, structure and enzymatic properties of the enzymes involved and genetic defects associated with this pathway.
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Affiliation(s)
- L Tabatabaie
- Department of Metabolic and Endocrine Diseases, University Medical Center Utrecht and Netherlands Metabolomics Centre, The Netherlands.
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21
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Kotchoni SO, Larrimore KE, Mukherjee M, Kempinski CF, Barth C. Alterations in the endogenous ascorbic acid content affect flowering time in Arabidopsis. Plant Physiol 2009; 149:803-15. [PMID: 19028878 PMCID: PMC2633856 DOI: 10.1104/pp.108.132324] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 11/17/2008] [Indexed: 05/18/2023]
Abstract
Ascorbic acid (AA) protects plants against abiotic stress. Previous studies suggested that this antioxidant is also involved in the control of flowering. To decipher how AA influences flowering time, we studied the four AA-deficient Arabidopsis (Arabidopsis thaliana) mutants vtc1-1, vtc2-1, vtc3-1, and vtc4-1 when grown under short and long days. These mutants flowered and senesced before the wild type irrespective of the photoperiod, a response that cannot simply be attributed to slightly elevated oxidative stress in the mutants. Transcript profiling of various flowering pathway genes revealed a correlation of altered mRNA levels and flowering time. For example, circadian clock and photoperiodic pathway genes were significantly higher in the vtc mutants than in the wild type under both short and long days, a result that is consistent with the early-flowering phenotype of the mutants. In contrast, when the AA content was artificially increased, flowering was delayed, which correlated with lower mRNA levels of circadian clock and photoperiodic pathway genes compared with plants treated with water. Similar observations were made for the autonomous pathway. Genetic analyses demonstrated that various photoperiodic and autonomous pathway mutants are epistatic to the vtc1-1 mutant. In conclusion, our transcript and genetic analyses suggest that AA acts upstream of the photoperiodic and autonomous pathways.
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Affiliation(s)
- Simeon O Kotchoni
- Department of Biology, West Virginia University, Morgantown, West Virginia 26506, USA
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22
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Abstract
Diversity in macrophage responsiveness to inflammatory stimuli has resulted in the description of a new paradigm wherein macrophages are referred to as polarized into one of two distinct phenotypes, classically activated (M1) macrophages and alternatively activated (M2) macrophages. Classically activated, M1 or "killer" macrophages are thought to play a critical role in destroying foreign organisms and tumor cells, while alternatively activated M2 or "healer" macrophages are thought to be important in debris scavenging, wound healing, and angiogenesis. M2 macrophages may also play key roles in chronic infections, tumorigenesis, and tumor metastasis. It is therefore important to establish models of M1 and M2 polarized macrophages to study their characteristics and amenability to manipulation. M1 macrophages are typically derived from myeloid progenitors with murine macrophage-colony-stimulating factor (M-CSF, also known as CSF-1), while M2 macrophages are thought to be derived from mature M1 macrophages by treatment with interleukin-4 (IL-4) or IL-13. M2 macrophages can also be isolated from SH2-containing inositol 5'-phosphatase (SHIP)-/- mice by harvesting macrophages from peritoneal lavage fluids or they can be derived from SHIP-/- bone marrow aspirate cells with addition of 5% human serum. Upon stimulation with lipopolysaccharide (LPS), M1 macrophages produce high levels of proinflammatory cytokines, low levels of anti-inflammatory cytokines, and high levels of inducible nitric oxide synthase (iNOS), which leads to nitric oxide (NO) production. M2 macrophages, on the other hand, express high levels of M2 markers Ym1 and arginase I (ArgI) and, upon stimulation with LPS, produce relatively lower levels of proinflammatory cytokines and NO and higher levels of anti-inflammatory cytokines. In this chapter, we describe methods used in our laboratory to generate and characterize alternatively activated (M2) macrophages.
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Affiliation(s)
- Victor W H Ho
- The Terry Fox Laboratory, BC Cancer Research Centre, Vancouver, BC, Canada
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23
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Chen S, Hajirezaei MR, Zanor MI, Hornyik C, Debast S, Lacomme C, Fernie AR, Sonnewald U, Börnke F. RNA interference-mediated repression of sucrose-phosphatase in transgenic potato tubers (Solanum tuberosum) strongly affects the hexose-to-sucrose ratio upon cold storage with only minor effects on total soluble carbohydrate accumulation. Plant Cell Environ 2008; 31:165-176. [PMID: 17999659 DOI: 10.1111/j.1365-3040.2007.01747.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Storage of potato tubers at low temperatures leads to the accumulation of glucose and fructose in a process called 'cold sweetening'. The aim of this work was to investigate the role of sucrose-phosphatase (SPP) in potato tuber carbohydrate metabolism at low temperature (4 degrees C). To this end, RNA interference (RNAi) was used to reduce SPP expression in transgenic potato tubers. Analysis of SPP specific small interfering RNAs (siRNAs), SPP protein accumulation and enzyme activity indicated that SPP silencing in transgenic tubers was stable during the cold treatment. Analysis of soluble carbohydrates showed that in transgenic tubers, cold-induced hexogenesis was inhibited while, despite strongly reduced SPP activity, sucrose levels exceeded wild-type (WT) values four- to fivefold after 34 d of cold treatment. This led to a drastic change in the hexose-to-sucrose ratio from 1.9 in WT tubers to 0.15 to 0.11 in transgenic tubers, while the total amount of soluble sugars was largely unchanged in both genotypes. Sucrose-6(F)-phosphate (Suc6P), the substrate of SPP, accumulated in transgenic tubers in the cold which most likely enables the residual enzyme to operate with maximal catalytic activity in vivo and thus, in the long term, counterbalances reduced SPP activity in the transformants. Northern analysis revealed that cold-induced expression of vacuolar invertase (VI) was blocked in SPP-silenced tubers explaining a reduced sucrose-to-hexose conversion. Suc6P levels were found to negatively correlate with VI expression. A possible role of Suc6P in regulating VI expression is discussed.
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Affiliation(s)
- Shuai Chen
- Friedrich-Alexander-Universität, Lehrstuhl für Biochemie, Staudtstr. 5, 91058 Erlangen, Germany
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24
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Horan KA, Watanabe KI, Kong AM, Bailey CG, Rasko JEJ, Sasaki T, Mitchell CA. Regulation of FcγR-stimulated phagocytosis by the 72-kDa inositol polyphosphate 5-phosphatase: SHIP1, but not the 72-kDa 5-phosphatase, regulates complement receptor 3–mediated phagocytosis by differential recruitment of these 5-phosphatases to the phagocytic cup. Blood 2007; 110:4480-91. [PMID: 17682126 DOI: 10.1182/blood-2007-02-073874] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Macrophages phagocytose particles to resolve infections and remove apoptotic cells. Phosphoinositide 3-kinase generates phosphatidylinositol-3,4,5-trisphosphate [PtdIns(3,4,5)P3] is restricted to the phagocytic cup, promoting phagocytosis. The PtdIns(3,4,5)P3 5-phosphatase (5-ptase) Src homology 2 (SH2) domain-containing inositol-5-phosphatase 1 (SHIP1) inhibits phagocytosis. We report here that another PtdIns(3,4,5)P3-5-ptase, the 72-kDa-5-phosphatase (72-5ptase), inhibits Fcγ receptor (FcγR)– but not complement receptor 3 (CR3)–mediated phagocytosis, affecting pseudopod extension and phagosome closure. In contrast, SHIP1 inhibited FcγR and CR3 phagocytosis with greater effects on CR3-stimulated phagocytosis. The 72-5ptase and SHIP1 were both dynamically recruited to FcγR-stimulated phagocytic cups, but only SHIP1 was recruited to CR3-stimulated phagocytic cups. To determine whether 5-ptases focally degrade PtdIns(3,4,5)P3 at the phagocytic cup after specific stimuli, time-lapse imaging of specific biosensors was performed. Transfection of dominant-negative 72-5ptase or 72-5ptase small interfering RNA (siRNA) resulted in amplified and prolonged PtdIns(3,4,5)P3 at the phagocytic cup in response to FcγR- but not CR3-stimulation. In contrast, macrophages from Ship1−/−/AktPH-GFP transgenic mice exhibited increased and sustained PtdIns(3,4,5)P3 at the cup in response to CR3 activation, with minimal changes to FcγR activation. Therefore, 72-5ptase and SHIP1 exhibit specificity in regulating FcγR- versus CR3-stimulated phagocytosis by controlling the amplitude and duration of PtdIns(3,4,5)P3 at the phagocytic cup.
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Affiliation(s)
- Kristy A Horan
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
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25
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Lin GP, Li XY, Huang JW, Xiong L, Zhou KY. [Inhibitory effects of tumor suppressor gene PTEN on proliferation and metastasis of breast cancer ZR-75-1 cells]. Ai Zheng 2007; 26:1069-1073. [PMID: 17927875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
BACKGROUND & OBJECTIVE Tumor suppressor gene PTEN could not only inhibit the proliferation of cancer cells, but also inhibit their metastasis. However, the mechanism is still unclear. This study was to investigate the effects of PTEN gene on the proliferation and metastasis of human breast cancer ZR-75-1 cells, and explore the mechanisms. METHODS Wild-type PTEN (wt-PTEN) plasmid and phosphatase-defective PTEN (G129R-PTEN) plasmid were transfected into ZR-75-1 cells by liposome, respectively. Cell proliferation was detected by MTT assay. Transfected cells were selected by puromycin. The expression of PTEN protein was detected by Western blot. Cell adhesion and invasion were tested by adhesion test and invasion test. RESULTS The proliferation inhibition rate was significantly higher in wt-PTEN-transfected ZR-75-1 cells than in untransfected cells and G129R-PTEN-transfected cells (42.7% vs. 0% and 2.7%, P<0.01); there was no significant difference between untransfected cells and G129R-PTEN-transfected cells(P>0.05). The proliferation inhibition of ZR-75-1 cells was enhanced along with the increase of culture time and concentration of wt-PTEN. wt-PTEN also induced cell apoptosis. PTEN protein was expressed efficiently in the cells transfected with either wt-PTEN or G129R-PTEN. The inhibition rates of adhesion and invasion were significantly higher in wt-PTEN-transfected cells than in G129R-PTEN-transfected cells (65.7% vs. 8.8%, 70.4% vs. 6.9%, P<0.01). CONCLUSION Wild-type PTEN gene with dual-specific phosphatase activity can inhibit the proliferation and metastasis of ZR-75-1 cells.
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Affiliation(s)
- Guan-Ping Lin
- Department of Biochemistry and Molecular Biology, Guangdong Medical College, Zhanjiang, Guangdong, 524023, P. R. China.
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26
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Abstract
SHIP1 [SH2 (Src homology 2)-containing inositol phosphatase-1], an inositol 5-phosphatase expressed in haemopoietic cells, acts by hydrolysing the 5-phosphates from PtdIns(3,4,5)P(3) and Ins(1,3,4,5)P(4), thereby negatively regulating the PI3K (phosphoinositide 3-kinase) pathway. SHIP1 plays a major role in inhibiting proliferation of myeloid cells. As a result, SHIP1(-/-) mice have an increased number of neutrophils and monocytes/macrophages due to enhanced survival and proliferation of their progenitors. Although SHIP1 contributes to PtdIns(3,4,5)P(3) metabolism in T-lymphocytes, its exact role in this cell type is much less explored. Jurkat cells have recently emerged as an interesting tool to study SHIP1 function in T-cells because they do not express SHIP1 at the protein level, thereby allowing reintroduction experiments in a relatively easy-to-use system. Data obtained from SHIP1 reintroduction have revealed that SHIP1 not only acts as a negative player in T-cell lines proliferation, but also regulates critical pathways, such as NF-kappaB (nuclear factor kappaB) activation, and also appears to remarkably inhibit T-cell apoptosis. On the other hand, experiments using primary T-cells from SHIP1(-/-) mice have highlighted a new role for SHIP1 in regulatory T-cell development, but also emphasize that this protein is not required for T-cell proliferation. In support of these results, SHIP1(-/-) mice are lymphopenic, suggesting that SHIP1 function in T-cells differs from its role in the myeloid lineage.
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Affiliation(s)
- G Gloire
- GIGA, Virology and Immunology Unit, B34, University of Liège, 4000 Liège, Belgium.
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27
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Leung WH, Bolland S. The inositol 5'-phosphatase SHIP-2 negatively regulates IgE-induced mast cell degranulation and cytokine production. J Immunol 2007; 179:95-102. [PMID: 17579026 DOI: 10.4049/jimmunol.179.1.95] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aggregation of the high-affinity IgE receptor (FcepsilonRI) on mast cells initiates signaling pathways leading to degranulation and cytokine release. It has been reported that SHIP-1 negatively regulates FcepsilonRI-triggered pathways but it is unknown whether its homologous protein SHIP-2 has the same function. We have used a lentiviral-based RNA interference technique to obtain SHIP-2 knockdown bone marrow-derived mast cells (BMMCs) and have found that elimination of SHIP-2 results in both increased mast cell degranulation and cytokine (IL-4 and IL-13) gene expression upon FcepsilonRI stimulation. Elimination of SHIP-2 from BMMCs has no effect on FcepsilonRI-triggered calcium flux, tyrosine phosphorylation of MAPKs or in actin depolymerization following activation. Rather, we observe that absence of SHIP-2 results in increased activation of the small GTPase Rac-1 and in enhanced microtubule polymerization upon FcepsilonRI engagement. Coimmunoprecipitation experiments in rat basophilic leukemia (RBL 2H3) cells show that SHIP-2 interacts with the FcepsilonRI beta-chain, Gab2 and Lyn and that unlike SHIP-1, it does not associate with SHC in mast cells. Our results report a negative regulatory role of SHIP-2 on mast cell activation that is calcium independent and distinct from the regulation by SHIP-1.
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Affiliation(s)
- Wai-Hang Leung
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, MD 20852, USA
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28
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Tarasenko T, Kole HK, Chi AW, Mentink-Kane MM, Wynn TA, Bolland S. T cell-specific deletion of the inositol phosphatase SHIP reveals its role in regulating Th1/Th2 and cytotoxic responses. Proc Natl Acad Sci U S A 2007; 104:11382-7. [PMID: 17585010 PMCID: PMC2040907 DOI: 10.1073/pnas.0704853104] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 5'-phosphoinositol phosphatase SHIP negatively regulates signaling pathways triggered by antigen, cytokine and Fc receptors in both lymphocytes and myeloid cells. Mice with germ-line (null) deletion of SHIP develop a myeloproliferative-like syndrome that causes early lethality. Lymphocyte anomalies have been observed in SHIP-null mice, but it is unclear whether they are due to an intrinsic requirement of SHIP in these cells or a consequence of the severe myeloid pathology. To precisely address the function of SHIP in T cells, we have generated mice with T cell-specific deletion of SHIP. In the absence of SHIP, we found no differences in thymic selection or in the activation state and numbers of regulatory T cells in the periphery. In contrast, SHIP-deficient T cells do not skew efficiently to Th2 in vitro. Mice with T cell-specific deletion of SHIP show poor antibody responses on Alum/NP-CGG immunization and diminished Th2 cytokine production when challenged with Schistosoma mansoni eggs. The failure to skew to Th2 responses may be the consequence of increased basal levels of the Th1-associated transcriptional factor T-bet, resulting from enhanced sensitivity to cytokine-mediated T-bet induction. SHIP-deficient CD8(+) cells show enhanced cytotoxic responses, consistent with elevated T-bet levels in these cells. Overall our experiments indicate that in T cells SHIP negatively regulates cytokine-mediated activation in a way that allows effective Th2 responses and limits T cell cytotoxicity.
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Affiliation(s)
| | | | | | - Margaret M. Mentink-Kane
- Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Thomas A. Wynn
- Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Silvia Bolland
- Laboratories of *Immunogenetics and
- To whom correspondence should be addressed. E-mail:
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Liu J, Wang L, Harvey-White J, Huang BX, Kim HY, Luquet S, Palmiter RD, Krystal G, Rai R, Mahadevan A, Razdan RK, Kunos G. Multiple pathways involved in the biosynthesis of anandamide. Neuropharmacology 2007; 54:1-7. [PMID: 17631919 PMCID: PMC2219543 DOI: 10.1016/j.neuropharm.2007.05.020] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 05/21/2007] [Accepted: 05/22/2007] [Indexed: 11/29/2022]
Abstract
Endocannabinoids, including anandamide (arachidonoyl ethanolamide) have been implicated in the regulation of a growing number of physiological and pathological processes. Anandamide can be generated from its membrane phospholipid precursor N-arachidonoyl phosphatidylethanolamine (NAPE) through hydrolysis by a phospholipase D (NAPE-PLD). Recent evidence indicates, however, the existence of two additional, parallel pathways. One involves the sequential deacylation of NAPE by alpha,beta-hydrolase 4 (Abhd4) and the subsequent cleavage of glycerophosphate to yield anandamide, and the other one proceeds through phospholipase C-mediated hydrolysis of NAPE to yield phosphoanandamide, which is then dephosphorylated by phosphatases, including the tyrosine phosphatase PTPN22 and the inositol 5' phosphatase SHIP1. Conversion of synthetic NAPE to AEA by brain homogenates from wild-type and NAPE-PLD(-/-) mice can proceed through both the PLC/phosphatase and Abdh4 pathways, with the former being dominant at shorter (<10 min) and the latter at longer (60 min) incubations. In macrophages, the endotoxin-induced synthesis of anandamide proceeds uniquely through the phospholipase C/phosphatase pathway.
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Affiliation(s)
- Jie Liu
- Laboratory of Physiologic Studies, NIAAA/NIH, 5625 Fishers Lane, MS-9413, Bethesda, MD 20892-9413, USA.
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30
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Paraiso KHT, Ghansah T, Costello A, Engelman RW, Kerr WG. Induced SHIP deficiency expands myeloid regulatory cells and abrogates graft-versus-host disease. J Immunol 2007; 178:2893-900. [PMID: 17312133 DOI: 10.4049/jimmunol.178.5.2893] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Graft-vs-host disease (GVHD) is the leading cause of treatment-related death in allogeneic bone marrow (BM) transplantation. Immunosuppressive strategies to control GVHD are only partially effective and often lead to life-threatening infections. We previously showed that engraftment of MHC-mismatched BM is enhanced and GVHD abrogated in recipients homozygous for a germline SHIP mutation. In this study, we report the development of a genetic model in which SHIP deficiency can be induced in adult mice. Using this model, we show that the induction of SHIP deficiency in adult mice leads to a rapid and significant expansion of myeloid suppressor cells in peripheral lymphoid tissues. Consistent with expansion of myeloid suppressor cells, splenocytes and lymph node cells from adult mice with induced SHIP deficiency are significantly compromised in their ability to prime allogeneic T cell responses. These results demonstrate that SHIP regulates homeostatic signals for these immunoregulatory cells in adult physiology. Consistent with these findings, induction of SHIP deficiency before receiving a T cell-replete BM graft abrogates acute GVHD. These findings indicate strategies that target SHIP could increase the efficacy and utility of allogeneic BM transplantation, and thereby provide a curative therapy for a wide spectrum of human diseases.
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Affiliation(s)
- Kim H T Paraiso
- Immunology Program, H. Lee Moffitt Comprehensive Cancer Center and Research Institute, University of South Florida, 12902 Magnolia Avenue, Tampa, FL 33612, USA
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Séverin S, Gratacap MP, Lenain N, Alvarez L, Hollande E, Penninger JM, Gachet C, Plantavid M, Payrastre B. Deficiency of Src homology 2 domain-containing inositol 5-phosphatase 1 affects platelet responses and thrombus growth. J Clin Invest 2007; 117:944-52. [PMID: 17347685 PMCID: PMC1810573 DOI: 10.1172/jci29967] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Accepted: 01/09/2007] [Indexed: 12/16/2022] Open
Abstract
Platelets are critical for normal hemostasis. Their deregulation can lead to bleeding or to arterial thrombosis, a primary cause of heart attack and ischemic stroke. Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP1) is a 5-phosphatase capable of dephosphorylating the phosphatidylinositol 3,4,5-trisphosphate second messenger into phosphatidylinositol 3,4-bisphosphate. SHIP1 plays a critical role in regulating the level of these 2 lipids in platelets. Using SHIP1-deficient mice, we found that its loss affects platelet aggregation in response to several agonists with minor effects on fibrinogen binding and beta(3) integrin tyrosine phosphorylation. Accordingly, SHIP1-null mice showed defects in arterial thrombus formation in response to a localized laser-induced injury. Moreover, these mice had a prolonged tail bleeding time. Upon stimulation, SHIP1-deficient platelets showed large membrane extensions, abnormalities in the open canalicular system, and a dramatic decrease in close cell-cell contacts. Interestingly, SHIP1 appeared to be required for platelet contractility, thrombus organization, and fibrin clot retraction. These data indicate that SHIP1 is an important element of the platelet signaling machinery to support normal hemostasis. To our knowledge, this is the first report unraveling an important function of SHIP1 in the activation of hematopoietic cells, in contrast to its well-documented role in the negative regulation of lymphocytes.
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Affiliation(s)
- Sonia Séverin
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Marie-Pierre Gratacap
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Nadège Lenain
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Laetitia Alvarez
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Etienne Hollande
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Josef M. Penninger
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Christian Gachet
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Monique Plantavid
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Bernard Payrastre
- INSERM U 563, Centre de Physiopathologie de Toulouse Purpan et Université Paul Sabatier, Département d’ Oncogenèse et Signalisation dans les Cellules Hématopoïétiques, Toulouse, France.
INSERM U 311, Etablissement Français du Sang-Alsace, Strasbourg, France.
Laboratoire de Biologie Cellulaire et Moléculaire des Epithéliums, Université Paul Sabatier, Toulouse, France.
Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
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Abstract
Embryonic stem (ES) cells are pluripotent cells that have the ability to either self-renew or differentiate into any cell type found in the mammalian body. The signaling pathways required for self-renewal of these cells are yet to be defined. Previously we identified a stem cell-specific isoform of the protein SH2 domain-containing 5'-inositol phosphatase (SHIP) that we call s-SHIP, which is expressed in both pluripotent ES cells and adult tissue-specific multipotent cells, such as hematopoietic stem cells (HSCs). s-SHIP lacks an SH2 domain but contains a 5'-inositol phosphatase domain and several protein-protein interaction domains that potentially enable its participation in many different signaling pathways. Here we show that s-SHIP associates with gp130, which forms a heterodimeric complex with the leukemia inhibitory factor receptor (LIFR). Signaling through LIFR and other receptors that heterodimerize with gp130 is critical for growth and survival of ES cells and HSCs. Our findings provide biochemical evidence that s-SHIP participates in signaling pathways important for the maintenance of pluripotent stem cell populations.
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Affiliation(s)
- C Desponts
- Immunology Program, H. Lee Moffitt Comprehensive Cancer Center and Research Institute,University of South Florida, Tampa, FL 33612, USA
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33
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Zhou P, Kitaura H, Teitelbaum SL, Krystal G, Ross FP, Takeshita S. SHIP1 negatively regulates proliferation of osteoclast precursors via Akt-dependent alterations in D-type cyclins and p27. J Immunol 2007; 177:8777-84. [PMID: 17142780 DOI: 10.4049/jimmunol.177.12.8777] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Osteoclasts arise from macrophage progenitors in bone marrow (BMMs) as a consequence of signaling events elicited by M-CSF and receptor activator of NF-kappaB ligand, acting on their unique receptors, via c-Fms and receptor activator of NF-kappaB. Both receptors activate the PI3K and MAPK pathways, which promote cell proliferation and survival. SHIP1 is essential for normal bone homeostasis, as mice lacking the protein exhibit osteoporosis resulting from increased numbers of hyper-resorptive osteoclasts. In this study, we show that BMMs from SHIP1 null mice respond to M-CSF, but not receptor activator of NF-kappaB ligand, by increasing Akt activation. In consequence, there are up-regulation of D-type cyclins, down-regulation of the cyclin-dependent kinase inhibitor p27, and, therefore, increased phosphorylation of the retinoblastoma protein and cell proliferation. Surprisingly, cell survival of wild-type and knockout BMMs is unaltered. Finally, osteoclastogenesis and periarticular bone erosions are markedly increased in SHIP1(-/-) mice with inflammatory arthritis, a condition characterized by increased M-CSF expression. The SHIP1/Akt pathway therefore suppresses bone loss in pathological states associated with an excess of the cytokine.
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Affiliation(s)
- Ping Zhou
- Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA
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34
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35
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Oh SY, Zheng T, Bailey ML, Barber DL, Schroeder JT, Kim YK, Zhu Z. Src homology 2 domain-containing inositol 5-phosphatase 1 deficiency leads to a spontaneous allergic inflammation in the murine lung. J Allergy Clin Immunol 2006; 119:123-31. [PMID: 17208593 PMCID: PMC4757810 DOI: 10.1016/j.jaci.2006.08.029] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 06/22/2006] [Accepted: 08/07/2006] [Indexed: 01/13/2023]
Abstract
BACKGROUND Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP-1) controls the intracellular level of the phosphoinositide 3-kinase product phosphotidylinositol-3,4,5-trisphosphate and functions as a negative regulator of cytokine and immune receptor signaling. Emerging evidence suggests that the phosphoinositide 3-kinase pathway might be involved in allergic inflammation in the lung. However, the functional relevance of SHIP-1 in the T(H)2 activation pathway has not been established. SHIP-1(-/-) mice have spontaneous myeloproliferative inflammation in the lung, the nature of which has not been elucidated. We hypothesized that SHIP-1 plays an important role as a regulator in pulmonary allergic inflammation and in maintaining lung homeostasis. OBJECTIVE To test our hypothesis, we characterized the pulmonary phenotype of SHIP-1(-/-) mice. RESULTS Analyses of lung histopathology and bronchoalveolar lavage cellularity revealed that the majority of SHIP-1(-/-) mice had progressive and severe pulmonary inflammation of macrophages, lymphocytes, neutrophils, and eosinophils; mucous hyperplasia; airway epithelial hypertrophy; and subepithelial fibrosis. These pathologic changes were accompanied by exaggerated production of T(H)2 cytokines and chemokines, including IL-4, IL-13, eotaxin, and monocyte chemoattractant protein 1, in the lung. Furthermore, the number of mast cells significantly increased, and many of these cells were undergoing degranulation, which was correlated with increased content and spontaneous release of histamine in the lung tissue of SHIP-1(-/-) mice. CONCLUSION These findings provide strong evidence that mice lacking SHIP-1 have an allergic inflammation in the lung, suggesting that SHIP-1 plays an important role in regulating the T(H)2 signaling pathway and in maintaining lung homeostasis. CLINICAL IMPLICATIONS SHIP-1 as a regulator might be a potential therapeutic target for controlling allergic inflammation in diseases such as asthma.
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Affiliation(s)
- Sun-Young Oh
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore
| | - Tao Zheng
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore
| | - Monica L. Bailey
- Division of Cellular and Molecular Biology, Ontario Cancer Institute, Toronto
| | - Dwayne L. Barber
- Division of Cellular and Molecular Biology, Ontario Cancer Institute, Toronto
| | - John T. Schroeder
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore
| | - Yoon-Keun Kim
- Department of Internal Medicine, Institute of Allergy and Clinical Immunology, Seoul National University College of Medicine, Seoul
| | - Zhou Zhu
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore
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36
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Wahle JA, Paraiso KHT, Costello AL, Goll EL, Sentman CL, Kerr WG. Cutting edge: dominance by an MHC-independent inhibitory receptor compromises NK killing of complex targets. J Immunol 2006; 176:7165-9. [PMID: 16751359 DOI: 10.4049/jimmunol.176.12.7165] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inhibitory receptors that recognize MHC class I molecules regulate NK cell responses and self-tolerance. Recent evidence indicates that self-ligands not present in the MHC locus also can modulate NK function. In this study, we show that an inhibitory receptor that recognizes an MHC-independent ligand is over expressed in SHIP(-/-) mice at all stages of NK development and differentiation. Overexpression of this receptor compromises key cytolytic NK functions, including killing of allogeneic, tumor, and viral targets. These results further demonstrate the critical role that SHIP plays in regulation of the NK receptor repertoire and show that regulation of MHC-independent inhibitory receptors is crucial for NK recognition and cytolysis of complex targets.
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MESH Headings
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/physiology
- Antigens, Ly/physiology
- Cell Differentiation/immunology
- Cells, Cultured
- Cytotoxicity Tests, Immunologic
- Cytotoxicity, Immunologic/genetics
- Down-Regulation/immunology
- Histocompatibility Antigens Class I/physiology
- Inositol Polyphosphate 5-Phosphatases
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Killer Cells, Natural/virology
- Lectins, C-Type/physiology
- Ligands
- Lymphocyte Activation/immunology
- Membrane Glycoproteins/antagonists & inhibitors
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Phosphoric Monoester Hydrolases/antagonists & inhibitors
- Phosphoric Monoester Hydrolases/deficiency
- Phosphoric Monoester Hydrolases/genetics
- Phosphoric Monoester Hydrolases/physiology
- Receptors, Immunologic/antagonists & inhibitors
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, Immunologic/physiology
- Receptors, NK Cell Lectin-Like
- Receptors, Natural Killer Cell
- Signal Transduction/immunology
- Signaling Lymphocytic Activation Molecule Family
- Up-Regulation/immunology
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Affiliation(s)
- Joseph A Wahle
- Department of Interdisciplinary Oncology, H. Lee Moffitt Comprehensive Cancer Center and Research Institute, University of South Florida, Tampa, FL 33612, USA
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37
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Rayapureddi JP, Hegde RS. Branchio-oto-renal syndrome associated mutations in Eyes Absent 1 result in loss of phosphatase activity. FEBS Lett 2006; 580:3853-9. [PMID: 16797546 DOI: 10.1016/j.febslet.2006.06.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 05/30/2006] [Accepted: 06/01/2006] [Indexed: 11/30/2022]
Abstract
The Eyes Absent (Eya) proteins are tyrosine phosphatases and transcriptional activators involved in cell-fate determination and organ development. Mutations in the gene encoding Eya homologue 1 have been implicated in the multi-organ developmental disorder branchio-oto-renal syndrome (BOR) and in ocular defects. Here we report that BOR-associated mutations lead to a loss of phosphatase activity in Eya1 proteins, while mutations associated with ocular defects yield Eya1 proteins with near normal levels of phosphatase activity. Furthermore we demonstrate that the N-terminal domain attenuates the catalytic activity of Eya suggesting a mechanism of regulation.
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Affiliation(s)
- Jayanagendra P Rayapureddi
- Cincinnati Children's Hospital Medical Center, Division of Developmental Biology, University of Cincinnati School of Medicine, Department of Pediatrics, 3333 Burnet Avenue, Cincinnati, OH 45229, United States
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38
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Kajitani K, Yamaguchi H, Dan Y, Furuichi M, Kang D, Nakabeppu Y. MTH1, an oxidized purine nucleoside triphosphatase, suppresses the accumulation of oxidative damage of nucleic acids in the hippocampal microglia during kainate-induced excitotoxicity. J Neurosci 2006; 26:1688-98. [PMID: 16467516 PMCID: PMC6793619 DOI: 10.1523/jneurosci.4948-05.2006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enhanced oxidative stress has been implicated in the excitotoxicity of the CNS, and 8-oxo-7,8-dihydro-guanine (8-oxoG), a major type of oxidative damage in nucleic acids, was reported to be accumulated in the rat hippocampus after kainate administration. We herein showed that the 8-oxoG levels in mitochondrial DNA and cellular RNA increased significantly in the CA3 subregion of the mouse hippocampus 6-12 h after kainate administration but returned to basal levels within a few days. Laser-scanning confocal microscopy revealed the 8-oxoG accumulation in mitochondrial DNA to be remarkable in CA3 microglia, whereas that in nuclear DNA or cellular RNA was also detected in the CA3 pyramidal cells and astrocytes. 8-oxoG accumulation in cellular DNA or RNA should be suppressed by MutT homolog 1 (MTH1) with 8-oxo-dGTPase (8-oxo-7,8-dihydro-2'-deoxyguanosine triphosphatase) activity and 8-oxoG-DNA glycosylase 1 (OGG1) with 8-oxoG DNA glycosylase activity. We thus examined the expression level of MTH1 and OGG1 in the mouse hippocampus after kainate administration. The Mth1 mRNA level decreased soon after kainate administration and then quickly recovered beyond the basal level, and a continuously increased MTH1 protein level was observed, whereas the Ogg1 mRNA level remained constant. MTH1-null and wild-type mice exhibited a similar degree of CA3 neuron loss after kainate administration; however, the 8-oxoG levels that accumulated in mitochondrial DNA and cellular RNA in the CA3 microglia significantly increased in the MTH1-null mice in comparison with wild-type mice, thus demonstrating that MTH1 efficiently suppresses the accumulation of 8-oxoG in both cellular DNA and RNA in the hippocampus, especially in microglia, caused by excitotoxicity.
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Nakabeppu Y, Kajitani K, Sakamoto K, Yamaguchi H, Tsuchimoto D. MTH1, an oxidized purine nucleoside triphosphatase, prevents the cytotoxicity and neurotoxicity of oxidized purine nucleotides. DNA Repair (Amst) 2006; 5:761-72. [PMID: 16621731 DOI: 10.1016/j.dnarep.2006.03.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2006] [Accepted: 03/01/2006] [Indexed: 10/24/2022]
Abstract
In human and rodent cells, MTH1, an oxidized purine nucleoside triphosphatase, efficiently hydrolyzes oxidized dGTP, GTP, dATP and ATP such as 2'-deoxy-8-oxoguanosine triphosphate (8-oxo-dGTP) and 2'-deoxy-2-hydroxyadenosine triphosphate (2-OH-dATP) in nucleotide pools, thus avoiding their incorporation into DNA or RNA. MTH1 is expressed in postmitotic neurons as well as in proliferative tissues, and it is localized both in the mitochondria and nucleus, thus suggesting that MTH1 plays an important role in the prevention of the mutagenicity and cytotoxicity of such oxidized purines as 8-oxoG which are known to accumulate in the cellular genome. Our recent studies with MTH1-deficient mice or cells revealed that MTH1 efficiently minimizes accumulation of 8-oxoG in both nuclear and mitochondrial DNA in the mouse brain as well as in cultured cells, thus contributing to the protection of the brain from oxidative stress.
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Affiliation(s)
- Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan.
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40
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Abstract
Serine deficiency disorders are rare defects in the biosynthesis of the amino acid L-serine. At present two disorders have been reported: 3-phosphoglycerate dehydrogenase deficiency and 3-phosphoserine phosphatase deficiency. These enzyme defects lead to severe neurological symptoms such as congenital microcephaly and severe psychomotor retardation and in addition in patients with 3-phosphoglycerate dehydrogenase deficiency to intractable seizures. These symptoms respond to a variable degree to treatment with L-serine, sometimes combined with glycine. In this paper the current practice of amino acid treatment with L-serine and glycine in serine deficiency is reviewed.
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Affiliation(s)
- T J de Koning
- Department of Metabolic Diseases, University Medical Centre Utrecht, KC 03.063.0, PO Box 85090, 3508 AB, Utrecht, The Netherlands.
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41
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Kashiwada M, Cattoretti G, McKeag L, Rouse T, Showalter BM, Al-Alem U, Niki M, Pandolfi PP, Field EH, Rothman PB. Downstream of Tyrosine Kinases-1 and Src Homology 2-Containing Inositol 5′-Phosphatase Are Required for Regulation of CD4+CD25+ T Cell Development. J Immunol 2006; 176:3958-65. [PMID: 16547230 DOI: 10.4049/jimmunol.176.7.3958] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The adaptor protein, downstream of tyrosine kinases-1 (Dok-1), and the phosphatase SHIP are both tyrosine phosphorylated in response to T cell stimulation. However, a function for these molecules in T cell development has not been defined. To clarify the role of Dok-1 and SHIP in T cell development in vivo, we compared the T cell phenotype of wild-type, Dok-1 knockout (KO), SHIP KO, and Dok-1/SHIP double-knockout (DKO) mice. Dok-1/SHIP DKO mice were runted and had a shorter life span compared with either Dok-1 KO or SHIP KO mice. Thymocyte numbers from Dok-1/SHIP DKO mice were reduced by 90%. Surface expression of both CD25 and CD69 was elevated on freshly isolated splenic CD4(+) T cells from SHIP KO and Dok-1/SHIP DKO, suggesting these cells were constitutively activated. However, these T cells did not proliferate or produce IL-2 after stimulation. Interestingly, the CD4(+) T cells from SHIP KO and Dok-1/SHIP DKO mice produced higher levels of TGF-beta, expressed Foxp3, and inhibited IL-2 production by CD3-stimulated CD4(+)CD25(-) T cells in vitro. These findings suggest Dok-1 and SHIP function in pathways that influence regulatory T cell development.
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Affiliation(s)
- Masaki Kashiwada
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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42
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Abstract
The SH2 domain-containing inositol 5'-phosphatase-1 (SHIP) has the potential to modulate multiple signaling pathways downstream of receptors that impact hematopoietic stem cell (HSC) biology. Therefore, we postulated that SHIP might play an important role in HSC homeostasis and function. Consistent with this hypothesis, HSC proliferation and numbers are increased in SHIP(-/-) mice. Despite expansion of the compartment, SHIP(-/-) HSCs exhibit reduced capacity for long-term repopulation. Interestingly, we observe that SHIP(-/-) stem/progenitor cells home inefficiently to bone marrow (BM), and consistent with this finding, have reduced surface levels of both CXCR4 and vascular cell adhesion marker-1 (VCAM-1). These studies demonstrate that SHIP is critical for normal HSC function, homeostasis, and homing.
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Affiliation(s)
- Caroline Desponts
- Immunology Program, H. Lee Moffitt Comprehensive Cancer Center, University of South Florida, Tampa, FL 33612, USA
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43
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Lin WH, Wang Y, Mueller-Roeber B, Brearley CA, Xu ZH, Xue HW. At5PTase13 modulates cotyledon vein development through regulating auxin homeostasis. Plant Physiol 2005; 139:1677-91. [PMID: 16299182 PMCID: PMC1310551 DOI: 10.1104/pp.105.067140] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Phosphatidylinositol signaling pathway and the relevant metabolites are known to be critical to the modulation of different aspects of plant growth, development, and stress responses. Inositol polyphosphate 5-phosphatase is a key enzyme involved in phosphatidylinositol metabolism and is encoded by an At5PTase gene family in Arabidopsis thaliana. A previous study shows that At5PTase11 mediates cotyledon vascular development probably through the regulation of intracellular calcium levels. In this study, we provide evidence that At5PTase13 modulates the development of cotyledon veins through its regulation of auxin homeostasis. A T-DNA insertional knockout mutant, At5pt13-1, showed a defect in development of the cotyledon vein, which was rescued completely by exogenous auxin and in part by brassinolide, a steroid hormone. Furthermore, the mutant had reduced auxin content and altered auxin accumulation in seedlings revealed by the DR5:beta-glucuronidase fusion construct in seedlings. In addition, microarray analysis shows that the transcription of key genes responsible for auxin biosynthesis and transport was altered in At5pt13-1. The At5pt13-1 mutant was also less sensitive to auxin inhibition of root elongation. These results suggest that At5PTase13 regulates the homeostasis of auxin, a key hormone controlling vascular development in plants.
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Affiliation(s)
- Wen-Hui Lin
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032 Shanghai, People's Republic of China
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44
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Yamaguchi H, Kajitani K, Dan Y, Furuichi M, Ohno M, Sakumi K, Kang D, Nakabeppu Y. MTH1, an oxidized purine nucleoside triphosphatase, protects the dopamine neurons from oxidative damage in nucleic acids caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Cell Death Differ 2005; 13:551-63. [PMID: 16273081 DOI: 10.1038/sj.cdd.4401788] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We previously reported that 8-oxoguanine (8-oxoG) accumulates in the cytoplasm of dopamine neurons in the substantia nigra of patients with Parkinson's disease and the expression of MTH1 carrying an oxidized purine nucleoside triphosphatase activity increases in these neurons, thus suggesting that oxidative damage in nucleic acids is involved in dopamine neuron loss. In the present study, we found that levels of 8-oxoG in cellular DNA and RNA increased in the mouse nigrostriatal system during the tyrosine hydroxylase (TH)-positive dopamine neuron loss induced by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MTH1-null mice exhibited a greater accumulation of 8-oxoG in mitochondrial DNA accompanied by a more significant decrease in TH and dopamine transporter immunoreactivities in the striatum after MPTP administration, than in wild-type mice. We thus demonstrated that MTH1 protects the dopamine neurons from oxidative damage in the nucleic acids, especially in the mitochondrial DNA of striatal nerve terminals of dopamine neurons.
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Affiliation(s)
- H Yamaguchi
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
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45
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Gao P, Wange RL, Zhang N, Oppenheim JJ, Howard OMZ. Negative regulation of CXCR4-mediated chemotaxis by the lipid phosphatase activity of tumor suppressor PTEN. Blood 2005; 106:2619-26. [PMID: 15994292 PMCID: PMC1895312 DOI: 10.1182/blood-2004-08-3362] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Accepted: 06/15/2005] [Indexed: 02/02/2023] Open
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a multifunctional tumor suppressor, has been shown to play a regulatory role in cell migration. Dictyostelium discoideum cells lacking PTEN exhibited impaired migration toward chemoattractant gradients. In the present study, we investigated the involvement of PTEN in chemotaxis of mammalian cells by examining PTEN-null Jurkat T cells. We observed that, in contrast to observations made in D discoideum, PTEN-null Jurkat T cells exhibited potent chemotactic responses to the chemokine stromal cell-derived factor 1alpha (SDF-1alpha), indicating that PTEN was not requisite for CXC chemokine receptor 4 (CXCR4)-mediated chemotaxis of Jurkat cells. Conversely, reconstitution of PTEN in Jurkat cells by using a tetracycline (Tet-on)-inducible expression system down-regulated CXCR4-mediated chemotaxis. Furthermore, we established the lipid phosphatase activity of PTEN as essential for its inhibitory effect on chemotaxis. In addition, using PTEN-expressing T-cell lines and primary T cells, we demonstrated that down-regulation of PTEN expression with vector-based small interfering RNAs (siRNAs) enhanced CXCR4-mediated chemotaxis. Based on these results, we conclude that PTEN expression negatively regulates chemotaxis of lymphoid mammalian cells via its lipid phosphatase activity. Our findings may account for the reported increase in metastatic activity of PTEN-null tumor cells.
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Affiliation(s)
- Ping Gao
- Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute-Frederick, PO Box B, Bldg 560, Rm 31-19, Frederick, MD 21702-1201, USA
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McCormack SE. What's your diagnosis? Oculocerebrorenal syndrome of Lowe. J Pediatr Ophthalmol Strabismus 2005; 42:272, 303. [PMID: 16250214 DOI: 10.3928/0191-3913-20050901-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Strassheim D, Kim JY, Park JS, Mitra S, Abraham E. Involvement of SHIP in TLR2-induced neutrophil activation and acute lung injury. J Immunol 2005; 174:8064-71. [PMID: 15944314 DOI: 10.4049/jimmunol.174.12.8064] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The SHIP converts phosphatidylinositol 3,4,5 triphosphate to phosphatidyl 3,4 biphosphate. SHIP has negative regulatory functions on PI3K-dependent signaling pathways, which occupy important roles in modulating neutrophil functions. We used neutrophils from transgenic SHIP(-/-) and SHIP(+/+) mice that were stimulated with peptidoglycan (PGN) to examine the role of SHIP in TLR2-induced neutrophil activation. SHIP(-/-) neutrophils demonstrated significantly increased activation of the PI3K-dependent kinase Akt after exposure to PGN. Release of cytokines and chemokines, including TNF-alpha, IL-1beta, IL-6, IL-10, and MIP-2, was also increased in SHIP(-/-) compared with SHIP(+/+) neutrophils. There was no difference in the nuclear translocation of the transcriptional factor NF-kappaB between PGN-stimulated SHIP(-/-) and SHIP(+/+) neutrophils. However, phosphorylation of the p65 subunit of NF-kappaB, an event essential for optimal transcriptional activity of NF-kappaB, was increased in TLR2-activated SHIP(-/-) neutrophils. SHIP(-/-) neutrophils demonstrated greater activation of ERK1/2 and p38 MAPKs than did SHIP(+/+) neutrophils after exposure to PGN. The severity of acute lung injury induced by PGN was greater in SHIP(-/-) as compared with SHIP(+/+) mice. These results demonstrate that SHIP has a negative regulatory role in TLR2-induced neutrophil activation and in the development of related in vivo neutrophil-dependent inflammatory processes, such as acute lung injury.
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Affiliation(s)
- Derek Strassheim
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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Chen Z, Trotman LC, Shaffer D, Lin HK, Dotan ZA, Niki M, Koutcher JA, Scher HI, Ludwig T, Gerald W, Cordon-Cardo C, Pandolfi PP. Crucial role of p53-dependent cellular senescence in suppression of Pten-deficient tumorigenesis. Nature 2005; 436:725-30. [PMID: 16079851 PMCID: PMC1939938 DOI: 10.1038/nature03918] [Citation(s) in RCA: 1505] [Impact Index Per Article: 79.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Accepted: 06/15/2005] [Indexed: 02/07/2023]
Abstract
Cellular senescence has been theorized to oppose neoplastic transformation triggered by activation of oncogenic pathways in vitro, but the relevance of senescence in vivo has not been established. The PTEN and p53 tumour suppressors are among the most commonly inactivated or mutated genes in human cancer including prostate cancer. Although they are functionally distinct, reciprocal cooperation has been proposed, as PTEN is thought to regulate p53 stability, and p53 to enhance PTEN transcription. Here we show that conditional inactivation of Trp53 in the mouse prostate fails to produce a tumour phenotype, whereas complete Pten inactivation in the prostate triggers non-lethal invasive prostate cancer after long latency. Strikingly, combined inactivation of Pten and Trp53 elicits invasive prostate cancer as early as 2 weeks after puberty and is invariably lethal by 7 months of age. Importantly, acute Pten inactivation induces growth arrest through the p53-dependent cellular senescence pathway both in vitro and in vivo, which can be fully rescued by combined loss of Trp53. Furthermore, we detected evidence of cellular senescence in specimens from early-stage human prostate cancer. Our results demonstrate the relevance of cellular senescence in restricting tumorigenesis in vivo and support a model for cooperative tumour suppression in which p53 is an essential failsafe protein of Pten-deficient tumours.
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Affiliation(s)
- Zhenbang Chen
- Cancer Biology and Genetics Program, Memorial Sloan-Kettering Cancer Center, Sloan-Kettering Institute, 1275 York Avenue, New York, New York 10021, USA
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Abstract
Abstract
Commitment of hemopoietic progenitors to the T-cell lineage is a crucial requirement for T-cell development, yet the timing and developmental cues regulating this process remain controversial. Here we have devised a technique to analyze the T-cell/B-cell lineage potential of precursors that have been recruited to the fetal mouse thymus but which have yet to contact the thymic epithelial microenvironment. We show that lymphoid progenitors arriving at the thymus are not bipotent T/B precursors, and provide evidence that intrathymic Notch signaling is not the mechanism determining T/B lineage choice in migrant precursors. Rather, we provide evidence that Notch signaling influences T/B lineage choice in lymphoid precursors through interactions with defined stromal components within the fetal liver. Collectively, our data redefine our understanding of the role and timing of Notch signaling in relation to lineage choices in lymphoid precursors.
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Affiliation(s)
- Benjamin C Harman
- Dept of Anatomy, Institute for Biomedical Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
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Sato W, Horie Y, Watanabe S, Suzuki A. [Tumor suppressor gene PTEN and non-alcoholic steatohepatitis (NASH)]. Nihon Rinsho 2005; 63:1475-83. [PMID: 16101243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Although hepatic steatosis had been considered to be a benign condition that does not deteriorate to either liver cirrhosis or hepatocellular carcinoma (HCC). Non-alcoholic steatohepatitis (NASH) is notable disease that has similar pathological features to alcoholic liver injury and progresses to liver cirrhosis and HCC. But the molecular mechanism for the onset of NASH, and for the transformation from steatosis to carcinogenesis are still unclear. Hepatocyte-specific PTEN deficient mice, we generated, have similar histological features to the patients of human NASH. These hepatocytes showed enhanced lipid accumulation, inflammatory change, and hyperoxidation. Moreover, they developed into HCC. Thus, impairment of PI3K/PTEN signaling may possibly be involved in a part of NASH/HCC cases in human.
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Affiliation(s)
- Wataru Sato
- Department of Gastroenterology, Akita University School of Medicine
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