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Mistretta M, Fiorito V, Allocco AL, Ammirata G, Hsu MY, Digiovanni S, Belicchi M, Napoli L, Ripolone M, Trombetta E, Mauri P, Farini A, Meregalli M, Villa C, Porporato PE, Miniscalco B, Crich SG, Riganti C, Torrente Y, Tolosano E. Flvcr1a deficiency promotes heme-based energy metabolism dysfunction in skeletal muscle. Cell Rep 2024; 43:113854. [PMID: 38412099 DOI: 10.1016/j.celrep.2024.113854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/07/2023] [Accepted: 02/08/2024] [Indexed: 02/29/2024] Open
Abstract
The definition of cell metabolic profile is essential to ensure skeletal muscle fiber heterogeneity and to achieve a proper equilibrium between the self-renewal and commitment of satellite stem cells. Heme sustains several biological functions, including processes profoundly implicated with cell metabolism. The skeletal muscle is a significant heme-producing body compartment, but the consequences of impaired heme homeostasis on this tissue have been poorly investigated. Here, we generate a skeletal-muscle-specific feline leukemia virus subgroup C receptor 1a (FLVCR1a) knockout mouse model and show that, by sustaining heme synthesis, FLVCR1a contributes to determine the energy phenotype in skeletal muscle cells and to modulate satellite cell differentiation and muscle regeneration.
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Affiliation(s)
- Miriam Mistretta
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Veronica Fiorito
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Anna Lucia Allocco
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Giorgia Ammirata
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Myriam Y Hsu
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Sabrina Digiovanni
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Oncology, University of Torino, 10126 Torino, Italy
| | - Marzia Belicchi
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari Centre, Università degli Studi di Milano, 20122 Milan, Italy
| | - Laura Napoli
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Michela Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Elena Trombetta
- Flow Cytometry Service, Clinical Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - PierLuigi Mauri
- National Research Council of Italy, Proteomics and Metabolomics Unit, Institute for Biomedical Technologies, ITB-CNR, 20054 Segrate, Milan, Italy; Clinical Proteomics Laboratory c/o ITB-CNR, CNR.Biomics Infrastructure, ElixirNextGenIT, 20054 Segrate, Milan, Italy
| | - Andrea Farini
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Mirella Meregalli
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari Centre, Università degli Studi di Milano, 20122 Milan, Italy
| | - Chiara Villa
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari Centre, Università degli Studi di Milano, 20122 Milan, Italy
| | - Paolo Ettore Porporato
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Barbara Miniscalco
- Department of Veterinary Sciences, University of Torino, 10095 Grugliasco, Torino, Italy
| | - Simonetta Geninatti Crich
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy
| | - Chiara Riganti
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Oncology, University of Torino, 10126 Torino, Italy
| | - Yvan Torrente
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari Centre, Università degli Studi di Milano, 20122 Milan, Italy.
| | - Emanuela Tolosano
- Molecular Biotechnology Center (MBC) "Guido Tarone", Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy.
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2
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Pan S, Hale AT, Lemieux ME, Raval DK, Garton TP, Sadler B, Mahaney KB, Strahle JM. Iron homeostasis and post-hemorrhagic hydrocephalus: a review. Front Neurol 2024; 14:1287559. [PMID: 38283681 PMCID: PMC10811254 DOI: 10.3389/fneur.2023.1287559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 11/21/2023] [Indexed: 01/30/2024] Open
Abstract
Iron physiology is regulated by a complex interplay of extracellular transport systems, coordinated transcriptional responses, and iron efflux mechanisms. Dysregulation of iron metabolism can result in defects in myelination, neurotransmitter synthesis, and neuronal maturation. In neonates, germinal matrix-intraventricular hemorrhage (GMH-IVH) causes iron overload as a result of blood breakdown in the ventricles and brain parenchyma which can lead to post-hemorrhagic hydrocephalus (PHH). However, the precise mechanisms by which GMH-IVH results in PHH remain elusive. Understanding the molecular determinants of iron homeostasis in the developing brain may lead to improved therapies. This manuscript reviews the various roles iron has in brain development, characterizes our understanding of iron transport in the developing brain, and describes potential mechanisms by which iron overload may cause PHH and brain injury. We also review novel preclinical treatments for IVH that specifically target iron. Understanding iron handling within the brain and central nervous system may provide a basis for preventative, targeted treatments for iron-mediated pathogenesis of GMH-IVH and PHH.
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Affiliation(s)
- Shelei Pan
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Andrew T. Hale
- Department of Neurosurgery, University of Alabama at Birmingham School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mackenzie E. Lemieux
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Dhvanii K. Raval
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Thomas P. Garton
- Department of Neurology, Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Brooke Sadler
- Department of Pediatrics, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Hematology and Oncology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
| | - Kelly B. Mahaney
- Department of Neurosurgery, Stanford University School of Medicine, Stanford University, Palo Alto, CA, United States
| | - Jennifer M. Strahle
- Department of Neurosurgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Pediatrics, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
- Department of Orthopedic Surgery, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO, United States
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3
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Rathod DC, Vaidya SM, Hopp MT, Kühl T, Imhof D. Shapes and Patterns of Heme-Binding Motifs in Mammalian Heme-Binding Proteins. Biomolecules 2023; 13:1031. [PMID: 37509066 PMCID: PMC10377097 DOI: 10.3390/biom13071031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Heme is a double-edged sword. On the one hand, it has a pivotal role as a prosthetic group of hemoproteins in many biological processes ranging from oxygen transport and storage to miRNA processing. On the other hand, heme can transiently associate with proteins, thereby regulating biochemical pathways. During hemolysis, excess heme, which is released into the plasma, can bind to proteins and regulate their activity and function. The role of heme in these processes is under-investigated, with one problem being the lack of knowledge concerning recognition mechanisms for the initial association of heme with the target protein and the formation of the resulting complex. A specific heme-binding sequence motif is a prerequisite for such complex formation. Although numerous short signature sequences indicating a particular protein function are known, a comprehensive analysis of the heme-binding motifs (HBMs) which have been identified in proteins, concerning specific patterns and structural peculiarities, is missing. In this report, we focus on the evaluation of known mammalian heme-regulated proteins concerning specific recognition and structural patterns in their HBMs. The Cys-Pro dipeptide motifs are particularly emphasized because of their more frequent occurrence. This analysis presents a comparative insight into the sequence and structural anomalies observed during transient heme binding, and consequently, in the regulation of the relevant protein.
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Affiliation(s)
- Dhruv C Rathod
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany
| | - Sonali M Vaidya
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany
| | - Marie-T Hopp
- Department of Chemistry, Institute for Integrated Natural Sciences, University of Koblenz, D-56070 Koblenz, Germany
| | - Toni Kühl
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, D-53121 Bonn, Germany
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4
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Complex response to physiological and drug-induced hepatic heme demand in monoallelic ALAS1 mice. Mol Genet Metab Rep 2021; 29:100818. [PMID: 34900592 PMCID: PMC8639769 DOI: 10.1016/j.ymgmr.2021.100818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 01/11/2023] Open
Abstract
Regulation of 5-aminolevulinate synthase 1 (ALAS1) for nonerythroid heme is critical for respiration, cell signaling mechanisms and steroid/drug metabolism. ALAS1 is induced in some genetic disorders but unlike other genes in the heme pathway, a gene variant of ALAS1 associated with inherited disease has not been reported. BALB/c mice carrying a null ALAS1 allele caused by a βGEO insert were developed and used to determine the consequences of heme demand of a semi gene copy number. Homozygous disruption of ALAS1 (−/−) was lethal for embryo development post day 6.5 but expression in heterozygotes (+/−) was sufficient for the number of offspring and survival. In both wild type (WT +/+) and +/− mice expression of ALAS1 RNA was greatest in liver and harderian gland and much lower in kidney, lung, heart, brain and spleen. The effects of one WT ALAS1 allele in +/− mice on mRNA levels in liver and harderian gland were less marked compared to brain and other organs that were examined. Many other genes were up-regulated by heterozygosity in liver and brain but to a minimal extent. Hepatic heme oxygenase 1 (HMOX1) mRNA expression was significantly lower in +/− mice but not in brain. No elevated translation of WT allele ALAS1 mRNA was detected in +/− liver as a compensatory mechanism for the disabled allele. Fasting induced ALAS1 mRNA in both WT and +/− mice but only in +/− was this manifest as increased ALAS1 protein. The hepatic protoporphyria-inducing drug 4-ethyl-DDC caused induction of hepatic ALAS1 mRNA and protein levels in both WT and +/− mice but markedly less in the mice with only one intact allele. The findings illustrate the complex response of ALAS1 expression for heme demand but limited evidence that upregulation of a wild type allele can compensate for a null allele.
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Key Words
- 4-ethyl-DDC, 4-ethyl-3,5-diethoxycarbonyl-2,6-dimethyl-1,4-dihydropyridine
- AIP, acute intermittent porphyria
- ALAS1, aminolevulinate synthase 1
- Aminolevulinic acid synthase 1
- Compensation, complex regulation
- FECH, ferrochetalase
- HMOX1, heme oxygenase 1
- Hepatic response
- PCR, polymerase chain reaction
- Semi null mice
- WT, wild type
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Ricci A, Di Pierro E, Marcacci M, Ventura P. Mechanisms of Neuronal Damage in Acute Hepatic Porphyrias. Diagnostics (Basel) 2021; 11:diagnostics11122205. [PMID: 34943446 PMCID: PMC8700611 DOI: 10.3390/diagnostics11122205] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 01/12/2023] Open
Abstract
Porphyrias are a group of congenital and acquired diseases caused by an enzymatic impairment in the biosynthesis of heme. Depending on the specific enzyme involved, different types of porphyrias (i.e., chronic vs. acute, cutaneous vs. neurovisceral, hepatic vs. erythropoietic) are described, with different clinical presentations. Acute hepatic porphyrias (AHPs) are characterized by life-threatening acute neuro-visceral crises (acute porphyric attacks, APAs), featuring a wide range of neuropathic (central, peripheral, autonomic) manifestations. APAs are usually unleashed by external "porphyrinogenic" triggers, which are thought to cause an increased metabolic demand for heme. During APAs, the heme precursors δ-aminolevulinic acid (ALA) and porphobilinogen (PBG) accumulate in the bloodstream and urine. Even though several hypotheses have been developed to explain the protean clinical picture of APAs, the exact mechanism of neuronal damage in AHPs is still a matter of debate. In recent decades, a role has been proposed for oxidative damage caused by ALA, mitochondrial and synaptic ALA toxicity, dysfunction induced by relative heme deficiency on cytochromes and other hemeproteins (i.e., nitric oxide synthases), pyridoxal phosphate functional deficiency, derangements in the metabolic pathways of tryptophan, and other factors. Since the pathway leading to the biosynthesis of heme is inscribed into a complex network of interactions, which also includes some fundamental processes of basal metabolism, a disruption in any of the steps of this pathway is likely to have multiple pathogenic effects. Here, we aim to provide a comprehensive review of the current evidence regarding the mechanisms of neuronal damage in AHPs.
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Affiliation(s)
- Andrea Ricci
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.)
| | - Elena Di Pierro
- Dipartimento di Medicina Interna, Fondazione IRCSS Cà Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Matteo Marcacci
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.)
| | - Paolo Ventura
- Internal Medicine Unit, Department of Medical and Surgical Science for Children and Adults, University of Modena e Reggio Emilia, 41124 Modena, Italy; (A.R.); (M.M.)
- Correspondence: ; Tel.: +39-059-4225-542
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Pischedda F, Cirnaru MD, Ponzoni L, Sandre M, Biosa A, Carrion MP, Marin O, Morari M, Pan L, Greggio E, Bandopadhyay R, Sala M, Piccoli G. LRRK2 G2019S kinase activity triggers neurotoxic NSF aggregation. Brain 2021; 144:1509-1525. [PMID: 33876242 DOI: 10.1093/brain/awab073] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/11/2021] [Accepted: 01/26/2021] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease is characterized by the progressive degeneration of dopaminergic neurons within the substantia nigra pars compacta and the presence of protein aggregates in surviving neurons. The LRRK2 G2019S mutation is one of the major determinants of familial Parkinson's disease cases and leads to late-onset Parkinson's disease with pleomorphic pathology, including α-synuclein accumulation and deposition of protein inclusions. We demonstrated that LRRK2 phosphorylates N-ethylmaleimide sensitive factor (NSF). We observed aggregates containing NSF in basal ganglia specimens from patients with Parkinson's disease carrying the G2019S variant, and in cellular and animal models expressing the LRRK2 G2019S variant. We found that LRRK2 G2019S kinase activity induces the accumulation of NSF in toxic aggregates. Of note, the induction of autophagy cleared NSF aggregation and rescued motor and cognitive impairment observed in aged hG2019S bacterial artificial chromosome (BAC) mice. We suggest that LRRK2 G2019S pathological phosphorylation impacts on NSF biochemical properties, thus causing the formation of cytotoxic protein inclusions.
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Affiliation(s)
- Francesca Pischedda
- CIBIO, Università degli Studi di Trento, Trento, Italy.,Dulbecco Telethon Institute, Rome, Italy
| | | | | | - Michele Sandre
- Department of Biomedical Sciences (DSB), University of Padova, Padova, Italy
| | - Alice Biosa
- Department of Biology, University of Padova, Padova, Italy
| | - Maria Perez Carrion
- CIBIO, Università degli Studi di Trento, Trento, Italy.,Unidad Asociada Neurodeath, Faculty of Medicine, University of Castilla-La Mancha, 02008, Albacete, Spain
| | - Oriano Marin
- Department of Biomedical Sciences (DSB), University of Padova, Padova, Italy
| | - Michele Morari
- Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara, Italy
| | - Lifeng Pan
- Shanghai Institute of Organic Chemistry, Shanghai, China
| | - Elisa Greggio
- Department of Biology, University of Padova, Padova, Italy
| | - Rina Bandopadhyay
- Reta Lila Weston Institute of Neurological Studies and Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | | | - Giovanni Piccoli
- CIBIO, Università degli Studi di Trento, Trento, Italy.,Dulbecco Telethon Institute, Rome, Italy
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Chiabrando D, Fiorito V, Petrillo S, Bertino F, Tolosano E. HEME: a neglected player in nociception? Neurosci Biobehav Rev 2021; 124:124-136. [PMID: 33545213 DOI: 10.1016/j.neubiorev.2021.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 12/16/2020] [Accepted: 01/08/2021] [Indexed: 12/12/2022]
Abstract
Despite increasing progress in the understanding of the pathophysiology of pain, current management of pain syndromes is still unsatisfactory. The recent discovery of novel pathways associated with pain insensitivity in humans represents a unique opportunity to improve our knowledge on the pathophysiology of pain. Heme metabolism recently emerged as a crucial regulator of nociception. Of note, alteration of heme metabolism has been associated with pain insensitivity as well as with acute and chronic pain in porphyric neuropathy and hemolytic diseases. However, the molecular mechanisms linking heme to the pain pathways still remain unclear. The review focuses on the major heme-regulated processes relevant for sensory neurons' maintenance, peripheral and central sensitization as well as for pain comorbidities, like anxiety and depression. By discussing the body of knowledge on the topic, we provide a novel perspective on the molecular mechanisms linking heme to nociception.
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Affiliation(s)
- Deborah Chiabrando
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy.
| | - Veronica Fiorito
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy
| | - Sara Petrillo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy
| | - Francesca Bertino
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy
| | - Emanuela Tolosano
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Turin, Italy
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8
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Forster YM, Green JL, Khatiwada A, Liberato JL, Narayana Reddy PA, Salvino JM, Bienz S, Bigler L, dos Santos WF, Karklin Fontana AC. Elucidation of the Structure and Synthesis of Neuroprotective Low Molecular Mass Components of the Parawixia bistriata Spider Venom. ACS Chem Neurosci 2020; 11:1573-1596. [PMID: 32343555 DOI: 10.1021/acschemneuro.0c00007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The South American social spider Parawixia bistriata produces a venom containing complex organic compounds with intriguing biological activities. The crude venom leads to paralysis in termites and stimulates l-glutamate uptake and inhibits GABA uptake in rat brain synaptosomes. Glutamate is the major neurotransmitter at the insect neuromuscular junction and at the mammalian central nervous system, suggesting a modulation of the glutamatergic system by the venom. Parawixin1, 2, and 10 (Pwx1, 2 and 10) are HPLC fractions that demonstrate this bioactivity. Pwx1 stimulates l-glutamate uptake through the main transporter in the brain, EAAT2, and is neuroprotective in in vivo glaucoma models. Pxw2 inhibits GABA and glycine uptake in synaptosomes and inhibits seizures and neurodegeneration, and Pwx10 increases l-glutamate uptake in synaptosomes and is neuroprotective and anticonvulsant, shown in in vivo epilepsy models. Herein, we investigated the low molecular mass compounds in this venom and have found over 20 small compounds and 36 unique acylpolyamines with and without amino acid linkers. The active substances in fractions Pwx1 and Pwx2 require further investigation. We elucidated and confirmed the structure of the active acylpolyamine in Pwx10. Both fraction Pwx10 and the synthesized component enhance the activity of transporters EAAT1 and EAAT2, and, importantly, offer in vitro neuroprotection against excitotoxicity in primary cultures. These data suggest that compounds with this mechanism could be developed into therapies for disorders in which l-glutamate excitotoxicity is involved.
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Affiliation(s)
- Yvonne M. Forster
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | - Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Apeksha Khatiwada
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - José Luiz Liberato
- Department of Biology, University of São Paulo, Ribeirão Preto, SP 14040-900, Brazil
| | | | - Joseph M. Salvino
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Stefan Bienz
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Zurich, CH 8057, Switzerland
| | | | - Andréia Cristina Karklin Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
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Falcucci RM, Wertz R, Green JL, Meucci O, Salvino J, Fontana ACK. Novel Positive Allosteric Modulators of Glutamate Transport Have Neuroprotective Properties in an in Vitro Excitotoxic Model. ACS Chem Neurosci 2019; 10:3437-3453. [PMID: 31257852 DOI: 10.1021/acschemneuro.9b00061] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Dysfunction of excitatory amino acid transporters (EAATs) has been implicated in the pathogenesis of various neurological disorders, such as stroke, brain trauma, epilepsy, and several neurodegenerative disorders. EAAT2 is the main transporter subtype responsible for glutamate clearance in the brain, and plays a key role in regulating neurotransmission and preventing excitotoxicity. Therefore, compounds that increase the activity of EAAT2 have therapeutic potential for neuroprotection. In previous studies, we used virtual screening approaches to identify novel positive allosteric modulators (PAMs) of EAAT2. These compounds were shown to selectively increase the activity of EAAT2 and increase Vmax of transport, without changing substrate affinity. In this work, our major effort was to investigate whether increasing the activity of EAAT2 by allosteric modulation would translate to neuroprotection in in vitro primary culture models of excitotoxicity. To investigate potential neuroprotective effects of one EAAT2 PAM, GT949, we subjected cultures to acute and prolonged excitotoxic insults by exogenous application of glutamate, or oxidative stress by application of hydrogen peroxide. GT949 administration did not result in neuroprotection in the oxidative stress model, likely due to damage of the glutamate transporters. However, GT949 displayed neuroprotective properties after acute and prolonged glutamate-mediated excitotoxicity. We propose that this compound prevents excess glutamate signaling by increasing the rate of glutamate clearance by EAAT2, thereby preventing excitotoxic damage and cell death. This novel class of compounds is therefore an innovative approach for neuroprotection with potential for translation in in vivo animal models of excitotoxicity.
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Affiliation(s)
- Romulo Martelli Falcucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Ryan Wertz
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Jennifer Leigh Green
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Olimpia Meucci
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Joseph Salvino
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Andréia Cristina Karklin Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, United States
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Devine MJ, Kittler JT. Mitochondria at the neuronal presynapse in health and disease. Nat Rev Neurosci 2019; 19:63-80. [PMID: 29348666 DOI: 10.1038/nrn.2017.170] [Citation(s) in RCA: 333] [Impact Index Per Article: 66.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Synapses enable neurons to communicate with each other and are therefore a prerequisite for normal brain function. Presynaptically, this communication requires energy and generates large fluctuations in calcium concentrations. Mitochondria are optimized for supplying energy and buffering calcium, and they are actively recruited to presynapses. However, not all presynapses contain mitochondria; thus, how might synapses with and without mitochondria differ? Mitochondria are also increasingly recognized to serve additional functions at the presynapse. Here, we discuss the importance of presynaptic mitochondria in maintaining neuronal homeostasis and how dysfunctional presynaptic mitochondria might contribute to the development of disease.
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Affiliation(s)
- Michael J Devine
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Josef T Kittler
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
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11
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Ifhar LS, Ene HM, Ben-Shachar D. Impaired heme metabolism in schizophrenia-derived cell lines and in a rat model of the disorder: Possible involvement of mitochondrial complex I. Eur Neuropsychopharmacol 2019; 29:577-589. [PMID: 30948194 DOI: 10.1016/j.euroneuro.2019.03.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 02/07/2023]
Abstract
Accumulating data point to heme involvement in neuropsychiatric disorders. Heme plays a role in major cellular processes such as signal transduction, protein complex assembly and regulation of transcription and translation. Its synthesis involves the mitochondria, which dysfunction, specifically that of the complex I (Co-I) of the electron transport chain is involved in the pathophysiology of schizophrenia (SZ). Here we aimed to demonstrate that deficits in Co-I affect heme metabolism. We show a significant decrease in heme levels in Co-I deficient SZ-derived EBV transformed lymphocytes (lymphoblastoid cell lines - LCLs) as compared to healthy subjects-derived cells (n = 9/cohort). Moreover, protein levels assessed by immunoblotting and mRNA levels assessed by qRT-PCR of heme catabolic enzyme, heme Oxygenase 1 (HO-1), and protein levels of heme downstream target phosphorylated eukaryotic initiation factor 2-alpha (Peif2a/eif2a) were significantly elevated in SZ-derived cells. In contrast, protein and mRNA levels of heme synthesis rate limiting enzyme aminolevulinic acid synthase-1 (ALAS1) were unchanged in SZ derived LCLs. In addition, inhibition of Co-I by rotenone in healthy subjects-derived LCLs (n = 4/cohort) exhibited an initial increase followed by a later decrease in heme levels. These findings were associated with opposite changes in heme's downstream target and HO-1 level, similar to our findings in SZ-derived cells. We also show a brain region specific pattern of impairment in Co-I subunits and in HO-1 and PeIF2α/eIF2α in the Poly-IC rat model of SZ (n = 6/cohort). Our results provide evidence for a link between CoI and heme metabolism both in-vitro and in-vivo suggesting its contribution to SZ pathophysiology.
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Affiliation(s)
- Lee S Ifhar
- Laboratory of Psychobiology, Department of Psychiatry, Rambam Health Care Campus, B. Rappaport Faculty of Medicine, Rappaport Family Institute for Research in Medical Sciences, Technion IIT, POB 9649, Haifa 31096 Israel
| | - Hila M Ene
- Laboratory of Psychobiology, Department of Psychiatry, Rambam Health Care Campus, B. Rappaport Faculty of Medicine, Rappaport Family Institute for Research in Medical Sciences, Technion IIT, POB 9649, Haifa 31096 Israel
| | - Dorit Ben-Shachar
- Laboratory of Psychobiology, Department of Psychiatry, Rambam Health Care Campus, B. Rappaport Faculty of Medicine, Rappaport Family Institute for Research in Medical Sciences, Technion IIT, POB 9649, Haifa 31096 Israel.
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12
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Ye F, Li X, Liu Y, Chang W, Liu W, Yuan J, Chen J. Hemin provides protection against lead neurotoxicity through heme oxygenase 1/carbon monoxide activation. J Appl Toxicol 2018; 38:1353-1364. [PMID: 29797346 DOI: 10.1002/jat.3646] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/23/2018] [Accepted: 04/17/2018] [Indexed: 12/19/2022]
Abstract
The neurotoxicity of lead (Pb) is well established, and oxidative stress is strongly associated with Pb-induced neurotoxicity. Heme oxygenase 1 (HO-1) is an important antioxidative enzyme for protection against oxidative stress in many disease models. In this study, we applied hemin, the substrate and a well-known inducer of HO-1, to investigate the possible role of HO-1 in protecting against Pb neurotoxicity. Hemin can significantly attenuate Pb acetate-induced cell death and oxidative stress in the hippocampus and frontal cortex of developmental rats. Consistent with in vivo results, the protective effects of hemin were also observed in SH-SY5Y cells after inducing cell survival and maintaining redox balance. However, knocking down HO-1 could significantly abolish the cytoprotective action of hemin against Pb toxicity, confirming HO-1 contributed to the protection. Finally, the HO-1-derived production of carbon monoxide, but not of bilirubin or Fe2+ , mediated the protective effects of HO-1 activation induced by hemin treatment against Pb-induced cell death and oxidative stress in SHSY5Y cells. Overall, this study showed that hemin provided protection against Pb neurotoxicity by HO-1/carbon monoxide activation.
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Affiliation(s)
- Fang Ye
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Xiaoyi Li
- Center for Translational Medicine, Wuhan Union Hospital, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Yawen Liu
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Wei Chang
- Department of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, People's Republic of China
| | - Wenqi Liu
- Department of Parasitology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Jing Yuan
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Jun Chen
- Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
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13
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Berrout L, Isokawa M. Ghrelin upregulates the phosphorylation of the GluN2B subunit of the NMDA receptor by activating GHSR1a and Fyn in the rat hippocampus. Brain Res 2017; 1678:20-26. [PMID: 28993142 DOI: 10.1016/j.brainres.2017.09.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/03/2017] [Accepted: 09/24/2017] [Indexed: 11/18/2022]
Abstract
Ghrelin and its receptor GHSR1a have been shown to exert numerous physiological functions in the brain, in addition to the well-established orexigenic role in the hypothalamus. Earlier work indicated that ghrelin stimulated the phosphorylation of the GluN1 subunit of the NMDA receptor (NMDAR) and enhanced synaptic transmission in the hippocampus. In the present study, we report that the exogenous application of ghrelin increased GluN2B phosphorylation. This increase was independent of GluN2B subunit activity or NMDAR channel activity. However, it depended on the activation of GHSR1a and Fyn as it was blocked by D-Lys3-GHRP-6 and PP2, respectively. Inhibitors for G-protein-regulated second messengers, such as Rp-cAMP, H89, TBB, ryanodine, and thapsigargin, unexpectedly enhanced GluN2B phosphorylation, suggesting that cAMP, PKA, casein kinase II, and cytosolic calcium signaling may oppose to the effect of ghrelin on the phosphorylation of GluN2B. Our findings suggest that 1) GluN2B is likely a molecular target of ghrelin and GHSR1a-driven signaling cascades, and 2) the ghrelin-mediated phosphorylation of GluN2B depends on Fyn activation under complex negative regulation by other second messengers.
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Affiliation(s)
- Liza Berrout
- Department of Health and Biomedical Sciences, University of Texas Rio Grande Valley, 1W University Blvd., Brownsville, TX 78520, United States
| | - Masako Isokawa
- Department of Health and Biomedical Sciences, University of Texas Rio Grande Valley, 1W University Blvd., Brownsville, TX 78520, United States.
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Longhena F, Zaltieri M, Grigoletto J, Faustini G, La Via L, Ghidoni R, Benussi L, Missale C, Spano P, Bellucci A. Depletion of Progranulin Reduces GluN2B-Containing NMDA Receptor Density, Tau Phosphorylation, and Dendritic Arborization in Mouse Primary Cortical Neurons. J Pharmacol Exp Ther 2017; 363:164-175. [DOI: 10.1124/jpet.117.242164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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15
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A heme-binding domain controls regulation of ATP-dependent potassium channels. Proc Natl Acad Sci U S A 2016; 113:3785-90. [PMID: 27006498 DOI: 10.1073/pnas.1600211113] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Heme iron has many and varied roles in biology. Most commonly it binds as a prosthetic group to proteins, and it has been widely supposed and amply demonstrated that subtle variations in the protein structure around the heme, including the heme ligands, are used to control the reactivity of the metal ion. However, the role of heme in biology now appears to also include a regulatory responsibility in the cell; this includes regulation of ion channel function. In this work, we show that cardiac KATP channels are regulated by heme. We identify a cytoplasmic heme-binding CXXHX16H motif on the sulphonylurea receptor subunit of the channel, and mutagenesis together with quantitative and spectroscopic analyses of heme-binding and single channel experiments identified Cys628 and His648 as important for heme binding. We discuss the wider implications of these findings and we use the information to present hypotheses for mechanisms of heme-dependent regulation across other ion channels.
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16
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A holistic view of cancer bioenergetics: mitochondrial function and respiration play fundamental roles in the development and progression of diverse tumors. Clin Transl Med 2016; 5:3. [PMID: 26812134 PMCID: PMC4728164 DOI: 10.1186/s40169-016-0082-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/11/2016] [Indexed: 02/01/2023] Open
Abstract
Since Otto Warburg made the first observation that tumor cells exhibit altered metabolism and bioenergetics in the 1920s, many scientists have tried to further the understanding of tumor bioenergetics. Particularly, in the past decade, the application of the state-of the-art metabolomics and genomics technologies has revealed the remarkable plasticity of tumor metabolism and bioenergetics. Firstly, a wide array of tumor cells have been shown to be able to use not only glucose, but also glutamine for generating cellular energy, reducing power, and metabolic building blocks for biosynthesis. Secondly, many types of cancer cells generate most of their cellular energy via mitochondrial respiration and oxidative phosphorylation. Glutamine is the preferred substrate for oxidative phosphorylation in tumor cells. Thirdly, tumor cells exhibit remarkable versatility in using bioenergetics substrates. Notably, tumor cells can use metabolic substrates donated by stromal cells for cellular energy generation via oxidative phosphorylation. Further, it has been shown that mitochondrial transfer is a critical mechanism for tumor cells with defective mitochondria to restore oxidative phosphorylation. The restoration is necessary for tumor cells to gain tumorigenic and metastatic potential. It is also worth noting that heme is essential for the biogenesis and proper functioning of mitochondrial respiratory chain complexes. Hence, it is not surprising that recent experimental data showed that heme flux and function are elevated in non-small cell lung cancer (NSCLC) cells and that elevated heme function promotes intensified oxygen consumption, thereby fueling tumor cell proliferation and function. Finally, emerging evidence increasingly suggests that clonal evolution and tumor genetic heterogeneity contribute to bioenergetic versatility of tumor cells, as well as tumor recurrence and drug resistance. Although mutations are found only in several metabolic enzymes in tumors, diverse mutations in signaling pathways and networks can cause changes in the expression and activity of metabolic enzymes, which likely enable tumor cells to gain their bioenergetic versatility. A better understanding of tumor bioenergetics should provide a more holistic approach to investigate cancer biology and therapeutics. This review therefore attempts to comprehensively consider and summarize the experimental data supporting our latest view of cancer bioenergetics.
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Bergonia HA, Franklin MR, Kushner JP, Phillips JD. A method for determining δ-aminolevulinic acid synthase activity in homogenized cells and tissues. Clin Biochem 2015; 48:788-95. [PMID: 25959086 PMCID: PMC4522353 DOI: 10.1016/j.clinbiochem.2015.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/23/2015] [Accepted: 04/29/2015] [Indexed: 11/27/2022]
Abstract
OBJECTIVE In mammalian cells the rate-limiting step in heme biosynthesis is the formation of δ-aminolevulinic acid (ALA). The reaction intermediates, porphyrins and iron and the final product, heme can be highly cytotoxic if allowed to accumulate. The importance of maintaining the levels of metabolic intermediates and heme within a narrow range is apparent based on the complex homeostatic system(s) that have developed. Ultimately, determining the enzymatic activity of ALA synthase (ALAS) present in the mitochondria is highly beneficial to confirm the effects of the transcriptional, translational and post-translational events. The aim of this study was to develop a highly sensitive assay for ALAS that could be used on whole tissue or cellular homogenates. DESIGN AND METHODS A systematic approach was used to optimize steps in formation of ALA by ALAS. Reducing the signal to noise ratio for the assay was achieved by derivatizing the ALA formed into a fluorescent product that could be efficiently separated by ultra performance liquid chromatography (UPLC) from other derivatized primary amines. The stability of ALAS activity in whole tissue homogenate and cellular homogenate was determined after extended storage at -80 °C. CONCLUSIONS A method for assaying ALAS has been developed that can be used with tissue homogenates or cellular lysates. There is no need to purify mitochondria and radiolabeled substrates are not needed for this assay. General laboratory reagents can be used to prepare the samples. Standard UPLC chromatography will resolve the derivatized ALA peak. Samples of tissue homogenate can be stored for approximately one year without significant loss of enzymatic activity.
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Affiliation(s)
- Hector A Bergonia
- Department of Medicine, University of Utah School of Medicine, 30N. 1900 E., 5C330 SOM, Salt Lake City, UT 84132, United States
| | - Michael R Franklin
- Department of Pharmacology and Toxicology, University of Utah School of Pharmacy, 30N. 1900 E., 5C330 SOM, Salt Lake City, UT 84132, United States
| | - James P Kushner
- Department of Medicine, University of Utah School of Medicine, 30N. 1900 E., 5C330 SOM, Salt Lake City, UT 84132, United States
| | - John D Phillips
- Department of Medicine, University of Utah School of Medicine, 30N. 1900 E., 5C330 SOM, Salt Lake City, UT 84132, United States
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18
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Hooda J, Alam M, Zhang L. Measurement of Heme Synthesis Levels in Mammalian Cells. J Vis Exp 2015:e51579. [PMID: 26275174 DOI: 10.3791/51579] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes. It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. The biosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathy and cancer. This technique uses [4-(14)C] 5-aminolevulinic acid ([(14)C] 5-ALA), one of the early precursors in the heme biosynthesis pathway to measure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [(14)C] 5-ALA followed by extraction of heme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relative levels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis were measured in several mammalian cell lines.
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Affiliation(s)
- Jagmohan Hooda
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas
| | - Maksudul Alam
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas
| | - Li Zhang
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas;
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19
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Abstract
Genetic variants in haem metabolism enzymes can be predisposition factors for adverse reactions in some individuals. New areas of haem biology may also be associated with idiosyncratic effects which are yet to be identified.
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Affiliation(s)
- Viktoria Vágány
- MRC Toxicology Unit
- Hodgkin Building
- University of Leicester
- Leicester LE1 9HN
- UK
| | - Andrew G. Smith
- MRC Toxicology Unit
- Hodgkin Building
- University of Leicester
- Leicester LE1 9HN
- UK
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20
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Kühl T, Imhof D. Regulatory Fe(II/III) heme: the reconstruction of a molecule's biography. Chembiochem 2014; 15:2024-35. [PMID: 25196849 DOI: 10.1002/cbic.201402218] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Indexed: 11/10/2022]
Abstract
More than 20 years of research on heme as a temporary effector molecule of proteins have revealed its widespread impact on virtually all primary functions in the human organism. As our understanding of this influence is still growing, a comprehensive overview of compiled data will give fresh impetus for creativity and developing new strategies in heme-related research. From known data concerning heme-regulated proteins and their involvement in the development of diseases, we provide concise information of Fe(II/III) heme as a regulator and the availability of "regulatory heme". The latter is dependent on the balance between free and bound Fe(II/III) heme, here termed "hemeostasis". Imbalance of this system can lead to the development of diseases that were not always attributed to this small molecule. Diseases such as cancer or Alzheimer's disease highlight the reawakened interest in heme, whose function was previously believed to be completely understood.
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Affiliation(s)
- Toni Kühl
- Pharmaceutical Chemistry I, Pharmaceutical Institute, University of Bonn, Brühler Strasse 7, 53119 Bonn (Germany).
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21
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Leucine-rich repeat kinase 2 binds to neuronal vesicles through protein interactions mediated by its C-terminal WD40 domain. Mol Cell Biol 2014; 34:2147-61. [PMID: 24687852 DOI: 10.1128/mcb.00914-13] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are associated with familial and sporadic Parkinson's disease (PD). LRRK2 is a complex protein that consists of multiple domains, including predicted C-terminal WD40 repeats. In this study, we analyzed functional and molecular features conferred by the WD40 domain. Electron microscopic analysis of the purified LRRK2 C-terminal domain revealed doughnut-shaped particles, providing experimental evidence for its WD40 fold. We demonstrate that LRRK2 WD40 binds and sequesters synaptic vesicles via interaction with vesicle-associated proteins. In fact, a domain-based pulldown approach combined with mass spectrometric analysis identified LRRK2 as being part of a highly specific protein network involved in synaptic vesicle trafficking. In addition, we found that a C-terminal sequence variant associated with an increased risk of developing PD, G2385R, correlates with a reduced binding affinity of LRRK2 WD40 to synaptic vesicles. Our data demonstrate a critical role of the WD40 domain within LRRK2 function.
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22
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Heme, an essential nutrient from dietary proteins, critically impacts diverse physiological and pathological processes. Nutrients 2014; 6:1080-102. [PMID: 24633395 PMCID: PMC3967179 DOI: 10.3390/nu6031080] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/14/2014] [Accepted: 02/19/2014] [Indexed: 12/11/2022] Open
Abstract
Heme constitutes 95% of functional iron in the human body, as well as two-thirds of the average person’s iron intake in developed countries. Hence, a wide range of epidemiological studies have focused on examining the association of dietary heme intake, mainly from red meat, with the risks of common diseases. High heme intake is associated with increased risk of several cancers, including colorectal cancer, pancreatic cancer and lung cancer. Likewise, the evidence for increased risks of type-2 diabetes and coronary heart disease associated with high heme intake is compelling. Furthermore, recent comparative metabolic and molecular studies of lung cancer cells showed that cancer cells require increased intracellular heme biosynthesis and uptake to meet the increased demand for oxygen-utilizing hemoproteins. Increased levels of hemoproteins in turn lead to intensified oxygen consumption and cellular energy generation, thereby fueling cancer cell progression. Together, both epidemiological and molecular studies support the idea that heme positively impacts cancer progression. However, it is also worth noting that heme deficiency can cause serious diseases in humans, such as anemia, porphyrias, and Alzheimer’s disease. This review attempts to summarize the latest literature in understanding the role of dietary heme intake and heme function in diverse diseases.
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Higashikawa F, Noda M, Awaya T, Tanaka T, Sugiyama M. 5-aminolevulinic acid, a precursor of heme, reduces both fasting and postprandial glucose levels in mildly hyperglycemic subjects. Nutrition 2014; 29:1030-6. [PMID: 23759263 DOI: 10.1016/j.nut.2013.02.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 02/05/2013] [Accepted: 02/08/2013] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The aim of this study was to evaluate the combined effects of 5-aminolevulinic acid phosphate (ALA-P) and iron on the glycemic index in mildly hyperglycemic adults. METHODS This double-blind, randomized placebo-controlled trial comprised 212 subjects (ages 35-70 y, fasting plasma glucose 105-125 mg/dL or hemoglobin (Hb)A1c 6.1%-7.1%). These participants were randomly assigned to four groups receiving either one of three doses of ALA-P and iron as sodium ferrous citrate (5 mg and 0.6 mg, 5 mg and 1.8 mg, or 15 mg and 1.8 mg, respectively) or a placebo, administered orally once a day over a 12-wk period. RESULTS Fifteen mg ALA-P plus 1.8 mg iron decreased the fasting plasma glucose level (2.32 mg/dL, 95% confidence interval [CI], 0.24-4.42, P = 0.029), serum glycoalbumin (0.22%, 95% CI, 0.02-0.42; P = 0.031), and 2h-oral glucose tolerance test levels (14.2 mg/dL, 95% CI, 1.8-26.6; P = 0.025) more than the placebo. However, the levels of HbA1c, fasting insulin, serum 1,5-anhydro-d-glucitol, and Homeostasis Model of Assessment-Insulin Resistance showed no appreciable changes. The participant numbers with impaired glucose tolerance and impaired fasting glucose decreased in the highest dosage group of ALA-P plus iron compared with the placebo group. CONCLUSION An oral intake of ALA would be a novel approach to prevent type 2 diabetes mellitus.
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Affiliation(s)
- Fumiko Higashikawa
- Project Research Center for Clinical Trial and Preventive Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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24
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Han JH, Yu TH, Ryu HH, Jun MH, Ban BK, Jang DJ, Lee JA. ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons. Exp Cell Res 2013; 319:1998-2005. [PMID: 23742895 DOI: 10.1016/j.yexcr.2013.05.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 05/08/2013] [Accepted: 05/16/2013] [Indexed: 12/14/2022]
Abstract
Tar-DNA binding protein of 43kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons.
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Affiliation(s)
- Jeong-Ho Han
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea
| | - Tae-Hoon Yu
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea
| | - Hyun-Hee Ryu
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea
| | - Mi-Hee Jun
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea
| | - Byung-Kwan Ban
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea
| | - Deok-Jin Jang
- Department of Applied Biology, College of Ecology and Environment, Kyungpook National University, 386, Gajang-dong, Sangju-si, Kyungbuk 742-711, Republic of Korea
| | - Jin-A Lee
- Department of Biotechnology, College of Life Science and Nanotechnology, Hannam University, Dajeon 305-811, Republic of Korea.
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25
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Hooda J, Cadinu D, Alam MM, Shah A, Cao TM, Sullivan LA, Brekken R, Zhang L. Enhanced heme function and mitochondrial respiration promote the progression of lung cancer cells. PLoS One 2013; 8:e63402. [PMID: 23704904 PMCID: PMC3660535 DOI: 10.1371/journal.pone.0063402] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 03/31/2013] [Indexed: 11/18/2022] Open
Abstract
Lung cancer is the leading cause of cancer-related mortality, and about 85% of the cases are non-small-cell lung cancer (NSCLC). Importantly, recent advance in cancer research suggests that altering cancer cell bioenergetics can provide an effective way to target such advanced cancer cells that have acquired mutations in multiple cellular regulators. This study aims to identify bioenergetic alterations in lung cancer cells by directly measuring and comparing key metabolic activities in a pair of cell lines representing normal and NSCLC cells developed from the same patient. We found that the rates of oxygen consumption and heme biosynthesis were intensified in NSCLC cells. Additionally, the NSCLC cells exhibited substantially increased levels in an array of proteins promoting heme synthesis, uptake and function. These proteins include the rate-limiting heme biosynthetic enzyme ALAS, transporter proteins HRG1 and HCP1 that are involved in heme uptake, and various types of oxygen-utilizing hemoproteins such as cytoglobin and cytochromes. Several types of human tumor xenografts also displayed increased levels of such proteins. Furthermore, we found that lowering heme biosynthesis and uptake, like lowering mitochondrial respiration, effectively reduced oxygen consumption, cancer cell proliferation, migration and colony formation. In contrast, lowering heme degradation does not have an effect on lung cancer cells. These results show that increased heme flux and function are a key feature of NSCLC cells. Further, increased generation and supply of heme and oxygen-utilizing hemoproteins in cancer cells will lead to intensified oxygen consumption and cellular energy production by mitochondrial respiration, which would fuel cancer cell proliferation and progression. The results show that inhibiting heme and respiratory function can effectively arrest the progression of lung cancer cells. Hence, understanding heme function can positively impact on research in lung cancer biology and therapeutics.
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Affiliation(s)
- Jagmohan Hooda
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Daniela Cadinu
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Md Maksudul Alam
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Ajit Shah
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Thai M. Cao
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Laura A. Sullivan
- Division of Surgical Oncology, Department of Surgery, The Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Rolf Brekken
- Division of Surgical Oncology, Department of Surgery, The Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Li Zhang
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas, United States of America
- * E-mail:
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Jiang P, Gan M, Ebrahim AS, Castanedes-Casey M, Dickson DW, Yen SHC. Adenosine monophosphate-activated protein kinase overactivation leads to accumulation of α-synuclein oligomers and decrease of neurites. Neurobiol Aging 2012. [PMID: 23200460 DOI: 10.1016/j.neurobiolaging.2012.11.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neuronal inclusions of α-synuclein (α-syn), termed Lewy bodies, are a hallmark of Parkinson disease (PD). Increased α-syn levels can occur in brains of aging human and neurotoxin-treated mice. Because previous studies have shown increased brain lactate levels in aging brains, in PD affected subjects when compared with age-matched controls, and in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP), we tested the effects of lactate exposure on α-syn in a cell-based study. We demonstrated that (1) lactate treatment led to α-syn accumulation and oligomerization in a time- and concentration-dependent manner; (2) such alterations were mediated via adenosine monophosphate-activated protein kinase (AMPK) and associated with increasing cytoplasmic phosphorylated AMPK levels; (3) AMPK activation facilitated α-syn accumulation and phosphorylation; (4) lactate treatment or overexpression of the active form of AMPK decreased α-syn turnover and neurite outgrowth; and (5) Lewy body-bearing neurons displayed abnormal cytoplasmic distribution of phosphorylated AMPK, which normally is located in nuclei. Together, our results suggest that chronic neuronal accumulation of α-syn induced by lactate-triggered AMPK activation in aging brains might be a novel mechanism underlying α-synucleinopathies in PD and related disorders.
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Affiliation(s)
- Peizhou Jiang
- Department of Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA
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Heyer NJ, Echeverria D, Woods JS. Disordered porphyrin metabolism: a potential biological marker for autism risk assessment. Autism Res 2012; 5:84-92. [PMID: 22298513 DOI: 10.1002/aur.236] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/24/2011] [Indexed: 01/19/2023]
Abstract
Autism (AUT) is a complex neurodevelopmental disorder that, together with Asperger's syndrome and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS), comprises the expanded classification of autistic spectrum disorder (ASD). The heterogeneity of ASD underlies the need to identify biomarkers or clinical features that can be employed to identify meaningful subtypes of ASD, define specific etiologies, and inform intervention and treatment options. Previous studies have shown that disordered porphyrin metabolism, manifested principally as significantly elevated urinary concentrations of pentacarboxyl (penta) and coproporphyrins, is commonly observed among some children with ASD. Here, we extend these observations by specifically evaluating penta and coproporphyrins as biological indicators of ASD among 76 male children comprising 30 with validated AUT, 14 with PDD-NOS, and 32 neurotypical (NT) controls. ASD children (AUT and PDD-NOS) had higher mean urinary penta (P < 0.006) and copro (P < 0.006) concentrations compared with same-aged NT children, each characterized by a number of extreme values. Using Receiver Operating Characteristic curve analysis, we evaluated the sensitivity and specificity of penta, copro, and their combined Z-scores in ASD detection. The penta sensitivity was 30% for AUT and 36% for PDD-NOS, with 94% specificity. The copro sensitivity was 33% and 14%, respectively, with 94% specificity. The combined Z-score measure had 33% and 21% sensitivity for AUT and PDD-NOS, respectively, with 100% specificity. These findings demonstrate that porphyrin measures are strong predictors of both AUT and PDD-NOS, and support the potential clinical utility of urinary porphyrin measures for identifying a subgroup of ASD subjects in whom disordered porphyrin metabolism may be a salient characteristic.
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Affiliation(s)
- Nicholas J Heyer
- Battelle Centers for Public Health Research and Evaluation, Seattle, Washington, USA
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Chernova T, Steinert JR, Richards P, Mistry R, Challiss RJ, Smith AG, Forsythe ID. Deficiency of regulatory heme causes an early synaptic failure in cultured neurons. Toxicology 2011. [DOI: 10.1016/j.tox.2011.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Chernova T, Steinert JR, Richards P, Mistry R, Challiss RAJ, Jukes-Jones R, Cain K, Smith AG, Forsythe ID. Early failure of N-methyl-D-aspartate receptors and deficient spine formation induced by reduction of regulatory heme in neurons. Mol Pharmacol 2011; 79:844-54. [PMID: 21325018 DOI: 10.1124/mol.110.069831] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
An initial stage of many neurodegenerative processes is associated with compromised synaptic function and precedes synapse loss, neurite fragmentation, and neuronal death. We showed previously that deficiency of heme, regulating many proteins of pharmacological importance, causes neurodegeneration of primary cortical neurons via N-methyl-d-aspartate receptor (NMDAR)-dependent suppression of the extracellular signal-regulated kinase 1/2 pathway. Here, we asked whether the reduction of heme causes synaptic perturbation before neurite fragmentation in neuronal cultures and investigated molecular mechanisms of synaptic dysfunction in these cells. We showed the change in the NR2B subunit phosphorylation that correlates with compromised NMDAR function after the reduction of regulatory heme and a rapid rescue of NR2B phosphorylation and NMDAR function by exogenous heme. Electrophysiological recordings demonstrated diminished NMDAR currents and NMDAR-mediated calcium influx after 24 h of inhibition of heme synthesis. These effects were reversed by treatment with heme; however, inhibition of the Src family kinases abolished the rescue effect of heme on NMDA-evoked currents. Diminished NMDAR current and Ca(2+) influx resulted in suppressed cGMP production and impairment of spine formation. Exogenous heme exerted rescue effects on NR2B tyrosine phosphorylation and NMDA-evoked currents within minutes, suggesting direct interactions within the NMDAR complex. These synaptic changes after inhibition of heme synthesis occurred at this stage without apparent dysfunction of major hemoproteins. We conclude that regulatory heme is necessary in maintaining NR2B phosphorylation and NMDAR function. NMDAR failure occurs before neurite fragmentation and may be a causal factor in neurodegeneration; this could suggest a route for an early pharmacological intervention.
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Affiliation(s)
- Tatyana Chernova
- MRC Toxicology Unit, University of Leicester, Leicester, United Kingdom.
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Li T, Woods JS. Cloning, expression, and biochemical properties of CPOX4, a genetic variant of coproporphyrinogen oxidase that affects susceptibility to mercury toxicity in humans. Toxicol Sci 2009; 109:228-36. [PMID: 19339664 DOI: 10.1093/toxsci/kfp066] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Coproporphyrinogen oxidase (CPOX) catalyzes the two-step decarboxylation of coproporphyrinogen-III to protoporphyrinogen-IX in the heme biosynthetic pathway. Previously we described a specific polymorphism (A814C) in exon 4 of the human CPOX gene (CPOX4) and demonstrated that CPOX4 is associated with both modified urinary porphyrin excretion and increased neurobehavioral deficits among human subjects with low-level mercury (Hg) exposure. Here, we sought to characterize the gene products of CPOX and CPOX4 with respect to biochemical and kinetic properties. Coproporphyrinogen-III was incubated with recombinantly expressed and purified human CPOX and CPOX4 enzymes at various substrate concentrations, with or without Hg(2+) present. Both CPOX and CPOX4 formed protoporphyrinogen-IX from coproporphyrinogen-III; however, the affinity of CPOX4 was twofold lower than that of CPOX (CPOX K(m) = 0.30 microM, V(max) = 0.52 pmol protoporphyrin-IX; CPOX4 K(m) = 0.54 microM, V(max) = 0.33 pmol protoporphyrin-IX). Hg(2+) specifically inhibited the second step of coproporphyrinogen-III decarboxylation (harderoporphyrinogen to protoporphyrinogen-IX) in a dose dependent manner. We also compared the catalytic activities of CPOX and CPOX4 in human liver samples. The specific activities of CPOX in mutant livers were significantly lower (40-50%) than those of either wild-type or heterozygous. Additionally, enzymes from mutant, heterozygous and wild-type livers were comparably inhibited by Hg(2+) (10 microM), decreasing CPOX4 activity to 25% that of the wild-type enzyme. These findings suggest that CPOX4 may predispose to impaired heme biosynthesis, which is limited further by Hg exposure. These effects may underlie increased susceptibility to neurological deficits previously observed in Hg-exposed humans with CPOX4.
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Affiliation(s)
- Tingting Li
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98105, USA
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Heyer NJ, Echeverria D, Martin MD, Farin FM, Woods JS. Catechol O-methyltransferase (COMT) VAL158MET functional polymorphism, dental mercury exposure, and self-reported symptoms and mood. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:599-609. [PMID: 19296409 PMCID: PMC2866512 DOI: 10.1080/15287390802706405] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Associations were evaluated between a functional single nucleotide polymorphism (Val158Met) in the gene encoding the catecholamine catabolic enzyme catechol O-methyltransferase (COMT), dental mercury exposure, and self-reported symptoms and mood among 183 male dentists and 213 female dental assistants. Self-reported symptoms, mood, and detailed work histories were obtained by computerized questionnaire. Spot urine samples were collected and analyzed for mercury concentrations to evaluate recent exposures, whereas a chronic mercury exposure index for all subjects was created from the work histories. COMT polymorphism status was determined using a polymerase chain reaction (PCR)-based assay. Scores for current, recent, and chronic self-reported symptom groups and six self-reported mood factors were evaluated with respect to recent and chronic mercury exposure and COMT polymorphism status. Multiple regression analysis controlled for age, socioeconomic status, tobacco and alcohol use, self-reported health problems, and medications. Separate evaluations were conducted for dentists and dental assistants. No consistent patterns of association between either urinary mercury concentration or the chronic index of mercury exposure and any category of symptoms were observed. However, consistent and significant associations were found between increased symptoms and the COMT polymorphism involving the double allelic substitution (full mutation) compared to subjects with no substitutions. Associations with mood were limited to polymorphism status among female dental assistants, and were observed for four of six mood factors and overall mood score. These findings extend evidence of genetic factors potentially affecting human susceptibility to the toxic effects of mercury and other environmental chemicals.
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Affiliation(s)
- Nicholas J. Heyer
- Battelle Centers for Public Health Research and Evaluation, Seattle, Washington, USA
| | - Diana Echeverria
- Battelle Centers for Public Health Research and Evaluation, Seattle, Washington, USA
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Michael D. Martin
- Department of Oral Medicine, University of Washington, Seattle, Washington, USA
| | - Federico M. Farin
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - James S. Woods
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
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Kannan M, Steinert JR, Forsythe ID, Smith AG, Chernova T. Mevastatin accelerates loss of synaptic proteins and neurite degeneration in aging cortical neurons in a heme-independent manner. Neurobiol Aging 2008; 31:1543-53. [PMID: 18951667 DOI: 10.1016/j.neurobiolaging.2008.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 07/11/2008] [Accepted: 09/05/2008] [Indexed: 02/07/2023]
Abstract
The therapeutic use of statins in reducing cholesterol requires careful assessment of potential neuroprotective and/or neurotoxic mechanisms. Chronic treatment with mevastatin (MV) exerts effects on cortical neuron morphology, protein expression and synaptic function in primary culture. MV impaired expression of synaptic proteins, reduced N-methyl-d-aspartate receptor (NMDAR) currents and accelerated neurodegeneration associated with aging. The down-regulating effect of MV on neuronal protein expression was additive with aging-associated decline in culture. Induction of Heme oxygenase-1 (HMOX1) by MV was superimposed on age-related up-regulation. Comparison of MV-treated and heme-deficient neurons showed that inhibition of heme synthesis (by succinyl acetone) had similar damaging effect on neurite integrity and MNDAR expression and function but not on expression of the receptor for neuropeptide Y1 (NPY1R). Replacement of heme in heme-deficient cultures restored protein expression but had no effect in those cultures co-treated with MV. Despite the dramatic induction of HMOX1, intracellular heme remained sufficient in MV-treated cultures, consistent with a heme-independent mechanism of MV-induced neurotoxicity and this was confirmed by analysing neurons with lentiviral over-expression of HMOX1. We conclude that MV exerts a neurotoxic effect in cultured neurons in a heme-independent manner.
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Chernova T, Higginson FM, Davies R, Smith AG. B2 SINE retrotransposon causes polymorphic expression of mouse 5-aminolevulinic acid synthase 1 gene. Biochem Biophys Res Commun 2008; 377:515-520. [PMID: 18929534 DOI: 10.1016/j.bbrc.2008.10.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 10/03/2008] [Indexed: 11/18/2022]
Abstract
5-Aminolevulinic acid synthase 1 (ALAS1) is the key enzyme in the homeostasis of nonerythroid heme and of fundamental importance in respiration, the metabolism of drugs, chemicals and steroids and cell signalling. The regulation of ALAS1 in response to stimuli occurs at transcriptional, translational and post-translational levels which could depend on inter-individual variation in basal expression. A genetic difference in hepatic ALAS1 mRNA levels between C57BL/6J and DBA/2 mice was detected by microarray and was >5-fold in whole liver or hepatocytes when estimated by qRT-PCR. Analysis of the ALAS1 promoter showed a 210 nt insert in the DBA/2 containing a B2 SINE retrotransposon causing a marked repression of expression by intracellular reporter systems. Deletions across the B2 SINE demonstrated that the full sequence was required for transcriptional inhibition. The findings show that a B2 SINE can contribute to the regulation of ALAS1 and SINEs in 5'-UTR regions contribute to inter-individual differences in gene expression.
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Affiliation(s)
| | | | | | - Andrew G Smith
- MRC Toxicology Unit, University of Leicester, Leicester, UK.
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Syapin PJ. Regulation of haeme oxygenase-1 for treatment of neuroinflammation and brain disorders. Br J Pharmacol 2008; 155:623-40. [PMID: 18794892 DOI: 10.1038/bjp.2008.342] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Injury to the CNS elicits a host defense reaction that utilizes astrocytes, microglia, neurons and oligodendrocytes. Neuroinflammation is a major host defense mechanism designed to restore normal structure and function after CNS insult, but like other forms of inflammation, chronic neuroinflammation may contribute to pathogenesis. The inducible haeme oxygenase isoform, haeme oxygenase-1 (HO-1), is a phase 2 enzyme upregulated in response to electrophilic xenobiotics, oxidative stress, cellular injury and disease. There is emerging evidence that HO-1 expression helps mediate the resolution of inflammation, including neuroinflammation. Whether this is solely because of the catabolism of haeme or includes additional mechanisms is unclear. This review provides a brief background on the molecular biology and biochemistry of haeme oxygenases and the actions of haeme, bilirubin, iron and carbon monoxide in the CNS. It then presents our current state of knowledge regarding HO-1 expression in the CNS, regulation of HO-1 induction in neural cells and discusses the prospect of pharmacological manipulation of HO-1 as therapy for CNS disorders. Because of recognized species and cellular differences in HO-1 regulation, a major objective of this review is to draw attention to areas where gaps exist in the experimental record regarding regulation of HO-1 in neural cells. The results indicate the HO-1 system to be an important therapeutic target in CNS disorders, but our understanding of HO-1 expression in human neural cells is severely lacking.
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Affiliation(s)
- P J Syapin
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6592, USA.
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