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Yasuda M, Lee S, Gan L, Bergonia HA, Desnick RJ, Phillips JD. Cimetidine Does Not Inhibit 5-Aminolevulinic Acid Synthase or Heme Oxygenase Activity: Implications for Treatment of Acute Intermittent Porphyria and Erythropoietic Protoporphyria. Biomolecules 2023; 14:27. [PMID: 38254627 PMCID: PMC10813085 DOI: 10.3390/biom14010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 01/24/2024] Open
Abstract
Acute intermittent porphyria (AIP) is characterized by acute neurovisceral attacks that are precipitated by the induction of hepatic 5-aminolevulinic acid synthase 1 (ALAS1). In erythropoietic protoporphyria (EPP), sun exposure leads to skin photosensitivity due to the overproduction of photoreactive porphyrins in bone marrow erythroid cells, where heme synthesis is primarily driven by the ALAS2 isozyme. Cimetidine has been suggested to be effective for the treatment of both AIP and EPP based on limited case reports. It has been proposed that cimetidine acts by inhibiting ALAS activity in liver and bone marrow for AIP and EPP, respectively, while it may also inhibit the hepatic activity of the heme catabolism enzyme, heme oxygenase (HO). Here, we show that cimetidine did not significantly modulate the activity or expression of endogenous ALAS or HO in wildtype mouse livers or bone marrow. Further, cimetidine did not effectively decrease hepatic ALAS activity or expression or plasma concentrations of the putative neurotoxic porphyrin precursors 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), which were all markedly elevated during an induced acute attack in an AIP mouse model. These results show that cimetidine is not an efficacious treatment for acute attacks and suggest that its potential clinical benefit for EPP is not via ALAS inhibition.
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Affiliation(s)
- Makiko Yasuda
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave Box 1498, New York, NY 10029, USA; (S.L.); (L.G.); (R.J.D.)
| | - Sangmi Lee
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave Box 1498, New York, NY 10029, USA; (S.L.); (L.G.); (R.J.D.)
| | - Lin Gan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave Box 1498, New York, NY 10029, USA; (S.L.); (L.G.); (R.J.D.)
| | - Hector A. Bergonia
- Department of Medicine, Hematology Division, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (H.A.B.); (J.D.P.)
| | - Robert J. Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave Box 1498, New York, NY 10029, USA; (S.L.); (L.G.); (R.J.D.)
| | - John D. Phillips
- Department of Medicine, Hematology Division, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; (H.A.B.); (J.D.P.)
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2
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Longo M, Paolini E, Meroni M, Jericó D, Córdoba KM, Battistin M, Gatti S, Di Pierro E, Fontanellas A, Dongiovanni P. The Alpha-Lipoic Acid Improves Glucose Metabolism and Hyperinsulinemia in Acute Intermittent Porphyria: A Nutritional Concept for the Management of Rare Disorders. Cell Mol Gastroenterol Hepatol 2023; 17:511-514. [PMID: 37979725 PMCID: PMC10884556 DOI: 10.1016/j.jcmgh.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/20/2023]
Affiliation(s)
- Miriam Longo
- Medicine and Metabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Erika Paolini
- Medicine and Metabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy; Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Marica Meroni
- Medicine and Metabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Daniel Jericó
- Hepatology: Porphyrias and Carcinogenesis Laboratory, CIMA-University of Navarra, Pamplona, Spain
| | - Karol M Córdoba
- Hepatology: Porphyrias and Carcinogenesis Laboratory, CIMA-University of Navarra, Pamplona, Spain
| | - Michele Battistin
- Center for Preclinical Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Stefano Gatti
- Center for Preclinical Research, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Elena Di Pierro
- Medicine and Metabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Antonio Fontanellas
- Hepatology: Porphyrias and Carcinogenesis Laboratory, Center for Applied Medical Research-University of Navarra, Pamplona, Spain; Navarra Institute for Health Research, Pamplona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Madrid, Spain
| | - Paola Dongiovanni
- Medicine and Metabolic Diseases, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
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3
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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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4
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de Souza PVS, Badia BDML, Farias IB, Pinto WBVDR, Oliveira ASB. Acute Hepatic Porphyria: Pathophysiological Basis of Neuromuscular Manifestations. Front Neurosci 2021; 15:715523. [PMID: 34646118 PMCID: PMC8502968 DOI: 10.3389/fnins.2021.715523] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Acute hepatic porphyria represents a rare, underdiagnosed group of inherited metabolic disorders due to hereditary defects of heme group biosynthesis pathway. Most patients have their definite diagnosis after several years of complex and disabling clinical manifestations and commonly after life-threatening acute neurovisceral episodes or severe motor handicap. Many key studies in the last two decades have been performed and led to the discovery of novel possible diagnostic and prognostic biomarkers and to the development of new therapeutic purposes, including small interfering RNA-based therapy, specifically driven to inhibit selectively delta-aminolevulinic acid synthase production and decrease the recurrence number of severe acute presentation for most patients. Several distinct mechanisms have been identified to contribute to the several neuromuscular signs and symptoms. This review article aims to present the current knowledge regarding the main pathophysiological mechanisms involved with the acute and chronic presentation of acute hepatic porphyria and to highlight the relevance of such content for clinical practice and in decision making about therapeutic options.
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Affiliation(s)
- Paulo Victor Sgobbi de Souza
- Division of Neuromuscular Diseases, Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Bruno de Mattos Lombardi Badia
- Division of Neuromuscular Diseases, Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Igor Braga Farias
- Division of Neuromuscular Diseases, Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | | | - Acary Souza Bulle Oliveira
- Division of Neuromuscular Diseases, Department of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
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Jericó D, Córdoba KM, Jiang L, Schmitt C, Morán M, Sampedro A, Alegre M, Collantes M, Santamaría E, Alegre E, Culerier C, de Mendoza AEH, Oyarzabal J, Martín MA, Peñuelas I, Ávila MA, Gouya L, Martini PGV, Fontanellas A. mRNA-based therapy in a rabbit model of variegate porphyria offers new insights into the pathogenesis of acute attacks. MOLECULAR THERAPY. NUCLEIC ACIDS 2021; 25:207-219. [PMID: 34458006 PMCID: PMC8368795 DOI: 10.1016/j.omtn.2021.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 05/13/2021] [Indexed: 11/28/2022]
Abstract
Variegate porphyria (VP) results from haploinsufficiency of protoporphyrinogen oxidase (PPOX), the seventh enzyme in the heme synthesis pathway. There is no VP model that recapitulates the clinical manifestations of acute attacks. Combined administrations of 2-allyl-2-isopropylacetamide and rifampicin in rabbits halved hepatic PPOX activity, resulting in increased accumulation of a potentially neurotoxic heme precursor, lipid peroxidation, inflammation, and hepatocyte cytoplasmic stress. Rabbits also showed hypertension, motor impairment, reduced activity of critical mitochondrial hemoprotein functions, and altered glucose homeostasis. Hemin treatment only resulted in a slight drop in heme precursor accumulation but further increased hepatic heme catabolism, inflammation, and cytoplasmic stress. Hemin replenishment did protect against hypertension, but it failed to restore action potentials in the sciatic nerve or glucose homeostasis. Systemic porphobilinogen deaminase (PBGD) mRNA administration increased hepatic PBGD activity, the third enzyme of the pathway, and rapidly normalized serum and urine porphyrin precursor levels. All features studied were improved, including those related to critical hemoprotein functions. In conclusion, the VP model recapitulates the biochemical characteristics and some clinical manifestations associated with severe acute attacks in humans. Systemic PBGD mRNA provided successful protection against the acute attack, indicating that PBGD, and not PPOX, was the critical enzyme for hepatic heme synthesis in VP rabbits.
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Affiliation(s)
- Daniel Jericó
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain
| | - Karol M Córdoba
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain
| | - Lei Jiang
- Moderna Inc., Cambridge, MA 02139, USA
| | - Caroline Schmitt
- Centre de Recherche sur l'Inflammation, Institut National de la Santé et de la Recherche Médicale U1149, 75018 Paris, France.,Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, Colombes et Université de Paris, 92701 Colombes, France
| | - María Morán
- Mitochondrial Diseases Laboratory, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ana Sampedro
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain
| | - Manuel Alegre
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,Department of Clinical Neurophysiology, Clínica Universidad de Navarra (CUN), 31008 Pamplona, Spain
| | - María Collantes
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,MicroPET Research Unit, CIMA-CUN, 31008 Pamplona, Spain.,Nuclear Medicine Department, CUN, 31008 Pamplona, Spain
| | - Eva Santamaría
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain
| | - Estíbaliz Alegre
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,Department of Biochemistry, Service of Biochemistry, Clínica Universidad de Navarra (CUN), 31008 Pamplona, Spain
| | - Corinne Culerier
- Centre de Recherche sur l'Inflammation, Institut National de la Santé et de la Recherche Médicale U1149, 75018 Paris, France.,Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, Colombes et Université de Paris, 92701 Colombes, France
| | | | - Julen Oyarzabal
- Small Molecule Discovery Platform, Molecular Therapeutics Program, CIMA-University of Navarra, 31008 Pamplona, Spain
| | - Miguel A Martín
- Mitochondrial Diseases Laboratory, Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), 28041 Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Iván Peñuelas
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,MicroPET Research Unit, CIMA-CUN, 31008 Pamplona, Spain.,Nuclear Medicine Department, CUN, 31008 Pamplona, Spain
| | - Matías A Ávila
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Laurent Gouya
- Centre de Recherche sur l'Inflammation, Institut National de la Santé et de la Recherche Médicale U1149, 75018 Paris, France.,Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, Colombes et Université de Paris, 92701 Colombes, France
| | | | - Antonio Fontanellas
- Hepatology Program, Centre for Applied Medical Research (CIMA), University of Navarra, 31008 Pamplona, Spain.,Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, 28029 Madrid, Spain
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6
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Stutterd CA, Kidd A, Florkowski C, Janus E, Fanjul M, Raizis A, Wu TY, Archer J, Leventer RJ, Amor DJ, Lukic V, Bahlo M, Gow P, Lockhart PJ, van der Knaap MS, Delatycki MB. Expanding the clinical and radiological phenotypes of leukoencephalopathy due to biallelic HMBS mutations. Am J Med Genet A 2021; 185:2941-2950. [PMID: 34089223 DOI: 10.1002/ajmg.a.62377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 11/07/2022]
Abstract
Pathogenic heterozygous variants in HMBS encoding the enzyme hydroxymethylbilane synthase (HMBS), also known as porphobilinogen deaminase, cause acute intermittent porphyria (AIP). Biallelic variants in HMBS have been reported in a small number of children with severe progressive neurological disease and in three adult siblings with a more slowly, progressive neurological disease and distinct leukoencephalopathy. We report three further adult individuals who share a distinct pattern of white matter abnormality on brain MRI in association with biallelic variants in HMBS, two individuals with homozygous variants, and one with compound-heterozygous variants. We present their clinical and radiological features and compare these with the three adult siblings previously described with leukoencephalopathy and biallelic HMBS variants. All six affected individuals presented with slowly progressive spasticity, ataxia, peripheral neuropathy, with or without mild cognitive impairment, and/or ocular disease with onset in childhood or adolescence. Their brain MRIs show mainly confluent signal abnormalities in the periventricular and deep white matter and bilateral thalami. This recognizable pattern of MRI abnormalities is seen in all six adults described here. Biallelic variants in HMBS cause a phenotype that is distinct from AIP. It is not known whether AIP treatments benefit individuals with HMBS-related leukoencephalopathy. One individual reported here had improved neurological function for 12 months following liver transplantation followed by decline and progression of disease.
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Affiliation(s)
- Chloe A Stutterd
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Neurology, Royal Children's Hospital, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia.,Victorian Clinical Genetics Services, Parkville, Australia
| | - Alexa Kidd
- Genetics Department, Canterbury Health laboratory, Christchurch, New Zealand
| | - Chris Florkowski
- Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
| | - Edward Janus
- Western Health General Internal Medicine Unit, St Albans, Australia.,Department of Medicine, Western Health, The University of Melbourne, Melbourne, Australia
| | - Miriam Fanjul
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Anthony Raizis
- Department of Molecular Pathology, Canterbury Health Laboratories, Christchurch, New Zealand
| | - Teddy Y Wu
- Department of Neurology, Christchurch Hospital, Christchurch, New Zealand
| | - John Archer
- Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Richard J Leventer
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Neurology, Royal Children's Hospital, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - David J Amor
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Vesna Lukic
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Paul Gow
- Liver Transplant Unit, Austin Hospital, University of Melbourne, Melbourne, Australia
| | - Paul J Lockhart
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Marjo S van der Knaap
- Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Martin B Delatycki
- Murdoch Children's Research Institute, Parkville, Australia.,Department of Pediatrics, University of Melbourne, Melbourne, Australia.,Victorian Clinical Genetics Services, Parkville, Australia
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7
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Porphyric Neuropathy: Pathophysiology, Diagnosis, and Updated Management. Curr Neurol Neurosci Rep 2020; 20:56. [PMID: 33026560 DOI: 10.1007/s11910-020-01078-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW To review the peripheral neurological complications of the acute hepatic porphyrias, as well as the latest advances in their pathophysiology and management. RECENT FINDINGS The diagnosis of porphyric neuropathy remains challenging as varying neuropathic patterns are encountered depending on disease stage, including a non-length-dependent distribution pattern. The major pathophysiologic mechanism is δ-aminolevulinic acid (ALA)-induced neurotoxicity. The less restrictive blood-nerve barrier in the autonomic ganglia and myenteric plexus may explain the frequency of dysautonomic manifestations. Recently, a prophylactic small interfering RNA (siRNA)-based therapy that reduces hepatic ALA Synthase-1 mRNA was approved for patients with recurrent neuro-visceral attacks. Neurologists should appreciate the varying patterns of porphyric neuropathy. As with most toxin-induced axonopathies, long-term outcomes depend on early diagnosis and treatment. While the short-term clinical and biochemical benefits of siRNA-based therapy are known, its long-term effects on motor recovery, chronic pain, and dysautonomic manifestations are yet to be determined.
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8
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Berger S, Stattmann M, Cicvaric A, Monje FJ, Coiro P, Hotka M, Ricken G, Hainfellner J, Greber-Platzer S, Yasuda M, Desnick RJ, Pollak DD. Severe hydroxymethylbilane synthase deficiency causes depression-like behavior and mitochondrial dysfunction in a mouse model of homozygous dominant acute intermittent porphyria. Acta Neuropathol Commun 2020; 8:38. [PMID: 32197664 PMCID: PMC7082933 DOI: 10.1186/s40478-020-00910-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/02/2020] [Indexed: 12/15/2022] Open
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant inborn error of heme biosynthesis due to a pathogenic mutation in the Hmbs gene, resulting in half-normal activity of hydroxymethylbilane synthase. Factors that induce hepatic heme biosynthesis induce episodic attacks in heterozygous patients. The clinical presentation of acute attacks involves the signature neurovisceral pain and may include psychiatric symptoms. Here we used a knock-in mouse line that is biallelic for the Hmbs c.500G > A (p.R167Q) mutation with ~ 5% of normal hydroxymethylbilane synthase activity to unravel the consequences of severe HMBS deficiency on affective behavior and brain physiology. Hmbs knock-in mice (KI mice) model the rare homozygous dominant form of AIP and were used as tool to elucidate the hitherto unknown pathophysiology of the behavioral manifestations of the disease and its neural underpinnings. Extensive behavioral analyses revealed a selective depression-like phenotype in Hmbs KI mice; transcriptomic and immunohistochemical analyses demonstrated aberrant myelination. The uncovered compromised mitochondrial function in the hippocampus of knock-in mice and its ensuing neurogenic and neuroplastic deficits lead us to propose a mechanistic role for disrupted mitochondrial energy production in the pathogenesis of the behavioral consequences of severe HMBS deficiency and its neuropathological sequelae in the brain.
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Affiliation(s)
- Stefanie Berger
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Miranda Stattmann
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Ana Cicvaric
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Francisco J Monje
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Pierluca Coiro
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Matej Hotka
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria
| | - Gerda Ricken
- Department of Neurology, Division of Neuropathology and Neurochemistry, Medical University of Vienna, Vienna, Austria
| | - Johannes Hainfellner
- Department of Neurology, Division of Neuropathology and Neurochemistry, Medical University of Vienna, Vienna, Austria
| | - Susanne Greber-Platzer
- Department of Pediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Makiko Yasuda
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Daniela D Pollak
- Department of Neurophysiology and Neuropharmacology, Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse, 17, A-1090, Vienna, Austria.
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9
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Yasuda M, Gan L, Chen B, Yu C, Zhang J, Gama-Sosa MA, Pollak DD, Berger S, Phillips JD, Edelmann W, Desnick RJ. Homozygous hydroxymethylbilane synthase knock-in mice provide pathogenic insights into the severe neurological impairments present in human homozygous dominant acute intermittent porphyria. Hum Mol Genet 2020; 28:1755-1767. [PMID: 30615115 DOI: 10.1093/hmg/ddz003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 12/07/2018] [Accepted: 12/31/2018] [Indexed: 12/13/2022] Open
Abstract
Acute intermittent porphyria (AIP) is an inborn error of heme biosynthesis due to the deficiency of hydroxymethylbilane synthase (HMBS) activity. Human AIP heterozygotes have episodic acute neurovisceral attacks that typically start after puberty, whereas patients with homozygous dominant AIP (HD-AIP) have early-onset chronic neurological impairment, including ataxia and psychomotor retardation. To investigate the dramatically different manifestations, knock-in mice with human HD-AIP missense mutations c.500G>A (p.Arg167Glu) or c.518_519GC>AG (p.Arg173Glu), designated R167Q or R173Q mice, respectively, were generated and compared with the previously established T1/T2 mice with ~30% residual HMBS activity and the heterozygous AIP phenotype. Homozygous R173Q mice were embryonic lethal, while R167Q homozygous mice (R167Q+/+) had ~5% of normal HMBS activity, constitutively elevated plasma and urinary 5-aminolevulinic acid (ALA) and porphobilinogen (PBG), profound early-onset ataxia, delayed motor development and markedly impaired rotarod performance. Central nervous system (CNS) histology was grossly intact, but CNS myelination was delayed and overall myelin volume was decreased. Heme concentrations in liver and brain were similar to those of T1/T2 mice. Notably, ALA and PBG concentrations in the cerebral spinal fluid and CNS regions were markedly elevated in R167Q+/+ mice compared with T1/T2 mice. When the T1/T2 mice were administered phenobarbital, ALA and PBG markedly accumulated in their liver and plasma, but not in the CNS, indicating that ALA and PBG do not readily cross the blood-brain barrier. Taken together, these studies suggest that the severe HD-AIP neurological phenotype results from decreased myelination and the accumulation of locally produced neurotoxic porphyrin precursors within the CNS.
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Affiliation(s)
- Makiko Yasuda
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lin Gan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Brenden Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jinglan Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Miguel A Gama-Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,General Medical Research Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA
| | - Daniela D Pollak
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Stefanie Berger
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - John D Phillips
- Division of Hematology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA
| | | | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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10
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Chim H, Salgado CJ, Miller NL, Wolfe EM, Rao S, Pearse DD. Analysis of Epineurial Lidocaine Injection for Nerve Transfers in a Rat Sciatic Nerve Model. J Hand Surg Am 2019; 44:1027-1036. [PMID: 31421935 DOI: 10.1016/j.jhsa.2019.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 04/17/2019] [Accepted: 06/26/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE Nerve transfers for peripheral nerve injuries can result in variable outcomes. We investigated the neuroprotective effect of epineurial lidocaine injection in the donor nerve prior to transection, with the hypothesis that proximal axon loss would be decreased with consequent increased neuroregeneration and functional recovery. METHODS A rat sciatic nerve model was used with 4 intervention groups: (1) lidocaine; (2) lidocaine/calcium gluconate (CG); (3) CG; or (4) saline (control). Behavioral testing and qualitative and quantitative histological evaluation was performed at 8 and 12 weeks. Histological assays included transmission electron microscopy, retrograde fluorogold labeling, and whole mount immunostaining. RESULTS Functional assessments through the sciatic functional index and Basso, Beattie, and Bresnahan scale showed a statistically significant increase in recovery at 8 and 12 weeks with lidocaine treatment. Significantly higher axonal counts were obtained in the lidocaine-treated groups. Fragmentation and increased myelin damage was present in the CG and saline groups. Retrograde fluorogold labeling showed a statistically significant increase in the number of L4-6 dorsal root ganglion neurons in the lidocaine-treated groups. Whole mount immunostaining identified extension of the axonal growth cone past the nerve coaptation site in lidocaine-treated groups, but not in CG and saline groups. CONCLUSIONS Our results suggest that epineurial lidocaine injection prior to donor nerve transection for nerve transfer has a neuroprotective effect, resulting in increased proximal axon counts and improved functional recovery. CLINICAL RELEVANCE These findings may have direct clinical application because epineurial lidocaine can be used in surgery as a simple and inexpensive intervention for promoting improved clinical outcomes after nerve transfer.
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Affiliation(s)
- Harvey Chim
- Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Florida College of Medicine, Gainesville.
| | | | - Nicole L Miller
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Miami, FL
| | - Erin M Wolfe
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Miami, FL
| | - Sudheendra Rao
- Department of Neurological Surgery, The Neuroscience Program, The Interdisciplinary Stem Cell Institute, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL
| | - Damien D Pearse
- Department of Neurological Surgery, The Neuroscience Program, The Interdisciplinary Stem Cell Institute, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL
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11
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Pulgar VM, Yasuda M, Gan L, Desnick RJ, Bonkovsky HL. Sex differences in vascular reactivity in mesenteric arteries from a mouse model of acute intermittent porphyria. Mol Genet Metab 2019; 128:376-381. [PMID: 30639047 PMCID: PMC6612470 DOI: 10.1016/j.ymgme.2019.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/08/2018] [Accepted: 01/05/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND AIMS Acute intermittent porphyria (AIP) results from a partial deficiency of porphobilinogen deaminase (PBGD). Symptomatic AIP patients, most of whom are women, experience acute attacks characterized by severe abdominal pain and abrupt increases in blood pressure. Here, we characterized the reactivity of mesenteric arteries from male and female AIP mice with ~30% of normal PBGD activity and wild type C57BL/6 mice. METHODS An acute porphyric attack was induced in AIP mice by treatment with phenobarbital. Vascular responses to K+, phenylephrine (PE), acetylcholine (ACh), and hemin were determined (Wire Multi Myograph). RESULTS Maximal contraction to PE was increased in arteries from male and female AIP mice (p < .05) during an induced attack of acute porphyria. Female AIP arteries had increased sensitivity to PE (p < .05) even after nitric oxide (NO) blockade with Nω-nitro-L-arginine methyl ester (L-NAME) (p < .05). Maximal relaxation to ACh was similar in males and females with lower sensitivity in female AIP arteries (p < .05). Hemin induced greater relaxation in AIP arteries in both males and females (p < .05). SUMMARY/CONCLUSIONS Sex differences in this AIP mouse model include a pro-contractile response in females. These alterations may contribute to the increased blood pressure during an acute attack and provide a novel mechanism of action whereby heme ameliorates the attacks.
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Affiliation(s)
- Victor M Pulgar
- Department of Pharmaceutical Sciences, Campbell University, Buies Creek, NC, USA; Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
| | - Makiko Yasuda
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY, USA.
| | - Lin Gan
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY, USA.
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY, USA.
| | - Herbert L Bonkovsky
- Section on Gastroenterology & Hepatology, Wake Forest University/NC Baptist Medical Center, Winston-Salem, NC, USA.
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12
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Yasuda M, Desnick RJ. Murine models of the human porphyrias: Contributions toward understanding disease pathogenesis and the development of new therapies. Mol Genet Metab 2019; 128:332-341. [PMID: 30737139 PMCID: PMC6639143 DOI: 10.1016/j.ymgme.2019.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 02/07/2023]
Abstract
Mouse models of the human porphyrias have proven useful for investigations of disease pathogenesis and to facilitate the development of new therapeutic approaches. To date, mouse models have been generated for all major porphyrias, with the exception of X-linked protoporphyria (XLP) and the ultra rare 5-aminolevulinic acid dehydratase deficient porphyria (ADP). Mouse models have been generated for the three autosomal dominant acute hepatic porphyrias, acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), and variegate porphyria (VP). The AIP mice, in particular, provide a useful investigative model as they have been shown to have acute biochemical attacks when induced with the prototypic porphyrinogenic drug, phenobarbital. In addition to providing important insights into the disease pathogenesis of the neurological impairment in AIP, these mice have been valuable for preclinical evaluation of liver-targeted gene therapy and RNAi-mediated approaches. Mice with severe HMBS deficiency, which clinically and biochemically mimic the early-onset homozygous dominant AIP (HD-AIP) patients, have been generated and were used to elucidate the striking phenotypic differences between AIP and HD-AIP. Mice modeling the hepatocutaneous porphyria, porphyria cutanea tarda (PCT), made possible the identification of the iron-dependent inhibitory mechanism of uroporphyrinogen decarboxylase (UROD) that leads to symptomatic PCT. Mouse models for the two autosomal recessive erythropoietic porphyrias, congenital erythropoietic porphyria (CEP) and erythropoeitic protoporphyria (EPP), recapitulate many of the clinical and biochemical features of the severe human diseases and have been particularly useful for evaluation of bone marrow transplantation and hematopoietic stem cell (HSC)-based gene therapy approaches. The EPP mice have also provided valuable insights into the underlying pathogenesis of EPP-induced liver damage and anemia.
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Affiliation(s)
- Makiko Yasuda
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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13
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Chen B, Wang M, Gan L, Zhang B, Desnick RJ, Yasuda M. Characterization of the hepatic transcriptome following phenobarbital induction in mice with AIP. Mol Genet Metab 2019; 128:382-390. [PMID: 30777612 PMCID: PMC6612539 DOI: 10.1016/j.ymgme.2018.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 12/03/2018] [Accepted: 12/24/2018] [Indexed: 12/12/2022]
Abstract
Acute Intermittent Porphyria (AIP), an autosomal dominant hepatic disorder, results from hydroxymethylbilane synthase (HMBS) mutations that decrease the encoded enzymatic activity, thereby predisposing patients to life-threatening acute neurovisceral attacks. The ~1% penetrance of AIP suggests that other genetic factors modulate the onset and severity of the acute attacks. Here, we characterized the hepatic transcriptomic response to phenobarbital (PB) administration in AIP mice, which mimics the biochemical attacks of AIP. At baseline, the mRNA profiles of 14,138 hepatic genes prior to treatment were remarkably similar between AIP and the congenic wild-type (WT) mice. After PB treatment (~120 mg/kg x 3d), 1347 and 1120 genes in AIP mice and 422 and 404 genes in WT mice were uniquely up- and down-regulated, respectively, at a False Discovery Rate < 0.05. As expected, the ALAS1 expression increased 4.5-fold and 15.9-fold in the WT and AIP mice, respectively. ALA-dehydrogenase also was induced ~1.7-fold in PB-induced AIP mice, but was unchanged in PB-induced WT mice. There was no statistically significant difference in the overall expression of 155 hepatic cytochrome P450 enzymes, although Cyp2c40, Cyp2c68, Cyp2c69, Mgst3 were upregulated only in PB-induced AIP mice (>1.9-fold) and Cyp21a1 was upregulated only in PB-induced WT mice (>9-fold). Notably, the genes differentially expressed in induced AIP mice were enriched in circadian rhythm, mitochondria biogenesis and electron transport, suggesting these pathways were involved in AIP mice responding to PB treatment. These results advance our understanding of the hepatic metabolic changes in PB-induced AIP mice and have implications in the pathogenesis of AIP acute attacks.
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Affiliation(s)
- Brenden Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Lin Gan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Makiko Yasuda
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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14
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Stacpoole PW, Martyniuk CJ, James MO, Calcutt NA. Dichloroacetate-induced peripheral neuropathy. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 145:211-238. [PMID: 31208525 DOI: 10.1016/bs.irn.2019.05.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Dichloroacetate (DCA) has been the focus of research by both environmental toxicologists and biomedical scientists for over 50 years. As a product of water chlorination and a metabolite of certain industrial chemicals, DCA is ubiquitous in our biosphere at low μg/kg body weight daily exposure levels without obvious adverse effects in humans. As an investigational drug for numerous congenital and acquired diseases, DCA is administered orally or parenterally, usually at doses of 10-50mg/kg per day. As a therapeutic, its principal mechanism of action is to inhibit pyruvate dehydrogenase kinase (PDK). In turn, PDK inhibits the key mitochondrial energy homeostat, pyruvate dehydrogenase complex (PDC), by reversible phosphorylation. By blocking PDK, DCA activates PDC and, consequently, the mitochondrial respiratory chain and ATP synthesis. A reversible sensory/motor peripheral neuropathy is the clinically limiting adverse effect of chronic DCA exposure and experimental data implicate the Schwann cell as a toxicological target. It has been postulated that stimulation of PDC and respiratory chain activity by DCA in normally glycolytic Schwann cells causes uncompensated oxidative stress from increased reactive oxygen species production. Additionally, the metabolism of DCA interferes with the catabolism of the amino acids phenylalanine and tyrosine and with heme synthesis, resulting in accumulation of reactive molecules capable of forming adducts with DNA and proteins and also resulting in oxidative stress. Preliminary evidence in rodent models of peripheral neuropathy suggest that DCA-induced neurotoxicity may be mitigated by naturally occurring antioxidants and by a specific class of muscarinic receptor antagonists. These findings generate a number of testable hypotheses regarding the etiology and treatment of DCA peripheral neuropathy.
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Affiliation(s)
- Peter W Stacpoole
- Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States; Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, United States.
| | - Christopher J Martyniuk
- Department of Physiological Sciences, Center for Environmental and Human Toxicology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Margaret O James
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL, United States
| | - Nigel A Calcutt
- Department of Pathology, University of California San Diego, La Jolla, CA, United States
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15
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Kakoullis L, Louppides S, Papachristodoulou E, Panos G. Porphyrias and photosensitivity: pathophysiology for the clinician. Postgrad Med 2018; 130:673-686. [PMID: 30296862 DOI: 10.1080/00325481.2018.1533380] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Porphyrias are disorders caused by defects in the biosynthetic pathway of heme. Their manifestations can be divided into three distinct syndromes, each attributable to the accumulation of three distinct classes of molecules. The acute neurovisceral syndrome is caused by the accumulation of the neurotoxic porphyrin precursors, delta aminolevulinic acid, and porphobilinogen; the syndrome of immediate painful photosensitivity is caused by the lipid-soluble protoporphyrin IX and, the syndrome of delayed blistering photosensitivity, caused by the water-soluble porphyrins, uroporphyrin, and coproporphyrin. Porphyrias can manifest with one, or with a combination, of these syndromes, depending on whether one or more types of molecules are being accumulated. Iron plays a significant role in some of these conditions, as evidenced by improvements in both clinical manifestations and laboratory parameters, following iron depletion in porphyria cutanea tarda, or iron administration in some cases of X-linked erythropoietic protoporphyria. While the pathophysiology of a specific type of porphyrias, the protoporphyrias, appears to favor the administration of zinc, results so far have been conflicting, necessitating further studies in order to assess its potential benefit. The pathways involved in each disease, as well as insights into their pathobiological processes are presented, with an emphasis on the development of photosensitivity reactions.
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Affiliation(s)
- Loukas Kakoullis
- a Department of Internal Medicine , Nicosia General Hospital, University of Cyprus Medical School , Nicosia , Cyprus
| | - Stylianos Louppides
- a Department of Internal Medicine , Nicosia General Hospital, University of Cyprus Medical School , Nicosia , Cyprus
| | - Eleni Papachristodoulou
- a Department of Internal Medicine , Nicosia General Hospital, University of Cyprus Medical School , Nicosia , Cyprus
| | - George Panos
- a Department of Internal Medicine , Nicosia General Hospital, University of Cyprus Medical School , Nicosia , Cyprus.,b Department of Internal Medicine, Section of Infectious Diseases , Patras University General Hospital, University of Patras School of Medicine , Patras , Greece
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16
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Schmitt C, Lenglet H, Yu A, Delaby C, Benecke A, Lefebvre T, Letteron P, Paradis V, Wahlin S, Sandberg S, Harper P, Sardh E, Sandvik AK, Hov JR, Aarsand AK, Chiche L, Bazille C, Scoazec JY, To-Figueras J, Carrascal M, Abian J, Mirmiran A, Karim Z, Deybach JC, Puy H, Peoc'h K, Manceau H, Gouya L. Recurrent attacks of acute hepatic porphyria: major role of the chronic inflammatory response in the liver. J Intern Med 2018; 284:78-91. [PMID: 29498764 DOI: 10.1111/joim.12750] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Acute intermittent porphyria (AIP) is an inherited disorder of haem metabolism characterized by life-threatening acute neurovisceral attacks due to the induction of hepatic δ-aminolevulinic acid synthase 1 (ALAS1) associated with hydroxymethylbilane synthase (HMBS) deficiency. So far, the treatment of choice is hemin which represses ALAS1. The main issue in the medical care of AIP patients is the occurrence of debilitating recurrent attacks. OBJECTIVE The aim of this study was to determine whether chronic hemin administration contributes to the recurrence of acute attacks. METHODS A follow-up study was conducted between 1974 and 2015 and included 602 French AIP patients, of whom 46 had recurrent AIP. Moreover, we studied the hepatic transcriptome, serum proteome, liver macrophage polarization and oxidative and inflammatory profiles of Hmbs-/- mice chronically treated by hemin and extended the investigations to five explanted livers from recurrent AIP patients. RESULTS The introduction of hemin into the pharmacopeia has coincided with a 4.4-fold increase in the prevalence of chronic patients. Moreover, we showed that both in animal model and in human liver, frequent hemin infusions generate a chronic inflammatory hepatic disease which induces HO1 remotely to hemin treatment and maintains a high ALAS1 level responsible for recurrence. CONCLUSION Altogether, this study has important impacts on AIP care underlying that hemin needs to be restricted to severe neurovisceral crisis and suggests that alternative treatment targeting the liver such as ALAS1 and HO1 inhibitors, and anti-inflammatory therapies should be considered in patients with recurrent AIP.
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Affiliation(s)
- C Schmitt
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance publique-Hôpitaux de Paris (AP-HP), Colombes, France.,Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - H Lenglet
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - A Yu
- STIM CNRS ERL 7368, Physiologie des Cellules Cardiaques et Vasculaires, Tours, France
| | - C Delaby
- Laboratory for Clinical Biochemistry and Proteomics, Institute for Regenerative Medicine and Biotherapy (IRMB), CHU de Montpellier and Université Montpellier, Montpellier, France
| | - A Benecke
- Centre National de la Recherche Scientifique, Institut des Hautes Études Scientifiques, Bures-sur-Yvette, France.,Center for Innate Immunity and Immune Disease (CIIID), University of Washington School of Medicine, Seattle, WA, USA
| | - T Lefebvre
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance publique-Hôpitaux de Paris (AP-HP), Colombes, France.,Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - P Letteron
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France
| | - V Paradis
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,DHU Unity, Pathology Department, Hôpital Beaujon, AP-HP, Clichy, France
| | - S Wahlin
- Department of Gastroenterology and Hepatology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden
| | - S Sandberg
- Laboratory for Clinical Biochemistry, Norwegian Porphyria Centre (NAPOS), Haukeland University Hospital, Bergen, Norway.,Department of Global Health and Primary Health Care, University of Bergen, Bergen, Norway
| | - P Harper
- Porphyria Centre Sweden, Centre for Inherited Metabolic Diseases, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - E Sardh
- Porphyria Centre Sweden, Centre for Inherited Metabolic Diseases, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - A K Sandvik
- Department of Gastroenterology and Hepatology, St. Olav's University Hospital, Trondheim, Norway
| | - J R Hov
- Department of Transplantation Medicine, Norwegian PSC Research Center and Section of Gastroenterology, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - A K Aarsand
- Laboratory for Clinical Biochemistry, Norwegian Porphyria Centre (NAPOS), Haukeland University Hospital, Bergen, Norway.,Department of Global Health and Primary Health Care, University of Bergen, Bergen, Norway
| | - L Chiche
- Centre Hospitalier Universitaire Bordeaux, Chirurgie Hépatobiliaire et Pancréatique, Maison du Haut Lévèque, Bordeaux, France
| | - C Bazille
- Service d'Anatomie Pathologique, Centre Hospitalo-Universitaire de Caen, Caen, France
| | - J-Y Scoazec
- Service d'anatomopathologie, Institut Gustave Roussy, Villejuif, France
| | - J To-Figueras
- Biochemistry and Molecular Genetics Department, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | - M Carrascal
- CSIC/UAB Proteomics Laboratory, IIBB-CSIC, IDIBAPS, Barcelona, Spain
| | - J Abian
- CSIC/UAB Proteomics Laboratory, IIBB-CSIC, IDIBAPS, Barcelona, Spain
| | - A Mirmiran
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - Z Karim
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - J-C Deybach
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance publique-Hôpitaux de Paris (AP-HP), Colombes, France.,Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - H Puy
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance publique-Hôpitaux de Paris (AP-HP), Colombes, France.,Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
| | - K Peoc'h
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France.,Laboratory for Clinical Biochemistry, Hôpital Beaujon, AP-HP, Clichy, France
| | - H Manceau
- Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France.,Laboratory for Clinical Biochemistry, Hôpital Beaujon, AP-HP, Clichy, France
| | - L Gouya
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance publique-Hôpitaux de Paris (AP-HP), Colombes, France.,Centre de Recherche sur l'Inflammation (CRI), UMR1149 INSERM, Université Paris Diderot, site Bichat, Paris, France.,Laboratoire d'excellence, GR-Ex, Paris, France
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17
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Ruspini SF, Zuccoli JR, Lavandera JV, Martínez MDC, Oliveri LM, Gerez EN, Batlle AMDC, Buzaleh AM. Effects of volatile anaesthetics on heme metabolism in a murine genetic model of Acute Intermittent Porphyria. A comparative study with other porphyrinogenic drugs. Biochim Biophys Acta Gen Subj 2018; 1862:1296-1305. [PMID: 29476795 DOI: 10.1016/j.bbagen.2018.02.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 02/13/2018] [Accepted: 02/19/2018] [Indexed: 11/26/2022]
Abstract
BACKGROUND Acute Intermittent Porphyria (AIP) is an inherited disease produced by a deficiency of Porphobilinogen deaminase (PBG-D). The aim of this work was to evaluate the effects of Isoflurane and Sevoflurane on heme metabolism in a mouse genetic model of AIP to further support our previous proposal for avoiding their use in porphyric patients. A comparative study was performed administering the porphyrinogenic drugs allylisopropylacetamide (AIA), barbital and ethanol, and also between sex and mutation using AIP (PBG-D activity 70% reduced) and T1 (PBG-D activity 50% diminished) mice. METHODS The activities of 5-Aminolevulinic synthetase (ALA-S), PBG-D, Heme oxygenase (HO) and CYP2E1; the expression of ALA-S and the levels of 5-aminolevulinic acid (ALA) were measured in different tissues of mice treated with the drugs mentioned. RESULTS Isoflurane increased liver, kidney and brain ALA-S activity of AIP females but only affected kidney AIP males. Sevoflurane induced ALA-S activity in kidney and brain of female AIP group. PBG-D activity was further reduced by Isoflurane in liver male T1; in AIP male mice activity remained in its low basal levels. Ethanol and barbital also caused biochemical alterations. Only AIA triggered neurological signs similar to those observed during human acute attacks in male AIP being the symptoms less pronounced in females although ALA-S induction was greater. Heme degradation was affected. DISCUSSION Biochemical alterations caused by the porphyrinogenic drugs assayed were different in male and female mice and also between T1 and AIP being more affected the females of AIP group. GENERAL SIGNIFICANCE This is the first study using volatile anaesthetics in an AIP genetic model confirming Isoflurane and Sevoflurane porphyrinogenicity.
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Affiliation(s)
- Silvina Fernanda Ruspini
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina
| | - Johanna Romina Zuccoli
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina
| | - Jimena Verónica Lavandera
- Cátedra de Bromatología y Nutrición, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Marìa Del Carmen Martínez
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina; Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
| | - Leda María Oliveri
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina
| | - Esther Noemí Gerez
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina
| | - Alcira María Del Carmen Batlle
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina
| | - Ana María Buzaleh
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET, Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, Argentina; Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
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18
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Brunetti-Pierri N, Newsome PN. AAV-mediated liver-directed gene therapy for Acute Intermittent Porphyria: It is safe but is it effective? J Hepatol 2016; 65:666-667. [PMID: 27422751 DOI: 10.1016/j.jhep.2016.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 07/06/2016] [Indexed: 12/19/2022]
Affiliation(s)
- Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy; Department of Translational Medicine, Federico II University, Naples, Italy.
| | - Philip N Newsome
- National Institute for Health Research (NIHR) Birmingham Liver Biomedical Research Unit and Centre for Liver Research, University of Birmingham, Birmingham, UK
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19
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Kuo HC, Ro LS, Jung SM, Huang CC, Chu CC. Porphyric neuropathies in an acute intermittent porphyria family. Neuropathology 2015; 36:290-294. [DOI: 10.1111/neup.12272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 11/27/2022]
Affiliation(s)
- Hung-Chou Kuo
- Department of Neurology; Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine; Taoyuan Taiwan
| | - Long-Sun Ro
- Department of Neurology; Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine; Taoyuan Taiwan
| | - Shih-Ming Jung
- Department of Pathology; Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine; Taoyuan Taiwan
| | - Chin-Chang Huang
- Department of Neurology; Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine; Taoyuan Taiwan
| | - Chun-Che Chu
- Department of Neurology; Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine; Taoyuan Taiwan
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20
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Homedan C, Schmitt C, Laafi J, Gueguen N, Desquiret-Dumas V, Lenglet H, Karim Z, Gouya L, Deybach JC, Simard G, Puy H, Malthièry Y, Reynier P. Mitochondrial energetic defects in muscle and brain of a Hmbs-/- mouse model of acute intermittent porphyria. Hum Mol Genet 2015; 24:5015-23. [PMID: 26071363 DOI: 10.1093/hmg/ddv222] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/09/2015] [Indexed: 12/24/2022] Open
Abstract
Acute intermittent porphyria (AIP), an autosomal dominant metabolic disease (MIM #176000), is due to a deficiency of hydroxymethylbilane synthase (HMBS), which catalyzes the third step of the heme biosynthetic pathway. The clinical expression of the disease is mainly neurological, involving the autonomous, central and peripheral nervous systems. We explored mitochondrial oxidative phosphorylation (OXPHOS) in the brain and skeletal muscle of the Hmbs(-/-) mouse model first in the basal state (BS), and then after induction of the disease with phenobarbital and treatment with heme arginate (HA). The modification of the respiratory parameters, determined in mice in the BS, reflected a spontaneous metabolic energetic adaptation to HMBS deficiency. Phenobarbital induced a sharp alteration of the oxidative metabolism with a significant decrease of ATP production in skeletal muscle that was restored by treatment with HA. This OXPHOS defect was due to deficiencies in complexes I and II in the skeletal muscle whereas all four respiratory chain complexes were affected in the brain. To date, the pathogenesis of AIP has been mainly attributed to the neurotoxicity of aminolevulinic acid and heme deficiency. Our results show that mitochondrial energetic failure also plays an important role in the expression of the disease.
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Affiliation(s)
- Chadi Homedan
- UMR INSERM 1063, Département de Biochimie et Génétique and
| | - Caroline Schmitt
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier AP-HP, 178 rue des Renouillers, Colombes 92701, France, INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | | | - Naïg Gueguen
- Département de Biochimie et Génétique and UMR CNRS 6214 - INSERM 1083, Centre Hospitalier Universitaire, 4 rue Larrey, Angers 49933, France
| | - Valérie Desquiret-Dumas
- Département de Biochimie et Génétique and UMR CNRS 6214 - INSERM 1083, Centre Hospitalier Universitaire, 4 rue Larrey, Angers 49933, France
| | - Hugo Lenglet
- INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | - Zoubida Karim
- INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | - Laurent Gouya
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier AP-HP, 178 rue des Renouillers, Colombes 92701, France, INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | - Jean-Charles Deybach
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier AP-HP, 178 rue des Renouillers, Colombes 92701, France, INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | - Gilles Simard
- UMR INSERM 1063, Département de Biochimie et Génétique and
| | - Hervé Puy
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier AP-HP, 178 rue des Renouillers, Colombes 92701, France, INSERM U1149, CNRS ERL 8252, Center for Research on Inflammation (CRI), Université Paris Diderot, site Bichat, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France and Laboratory of Excellence, GR-Ex, Sorbonne Paris Cité, 16 rue Henri Huchard, Paris 75018, France
| | - Yves Malthièry
- UMR INSERM 1063, Département de Biochimie et Génétique and
| | - Pascal Reynier
- Département de Biochimie et Génétique and UMR CNRS 6214 - INSERM 1083, Centre Hospitalier Universitaire, 4 rue Larrey, Angers 49933, France,
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21
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Uchida Y, Zhang Z, Tachikawa M, Terasaki T. Quantitative targeted absolute proteomics of rat blood-cerebrospinal fluid barrier transporters: comparison with a human specimen. J Neurochem 2015; 134:1104-15. [DOI: 10.1111/jnc.13147] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 04/09/2015] [Accepted: 04/13/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Yasuo Uchida
- Graduate School of Pharmaceutical Sciences; Tohoku University; Sendai Japan
| | - Zhengyu Zhang
- Graduate School of Pharmaceutical Sciences; Tohoku University; Sendai Japan
| | - Masanori Tachikawa
- Graduate School of Pharmaceutical Sciences; Tohoku University; Sendai Japan
| | - Tetsuya Terasaki
- Graduate School of Pharmaceutical Sciences; Tohoku University; Sendai Japan
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22
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Martelli A, Schmucker S, Reutenauer L, Mathieu JRR, Peyssonnaux C, Karim Z, Puy H, Galy B, Hentze MW, Puccio H. Iron regulatory protein 1 sustains mitochondrial iron loading and function in frataxin deficiency. Cell Metab 2015; 21:311-323. [PMID: 25651183 DOI: 10.1016/j.cmet.2015.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/22/2014] [Accepted: 01/16/2015] [Indexed: 12/22/2022]
Abstract
Mitochondrial iron accumulation is a hallmark of diseases associated with impaired iron-sulfur cluster (Fe-S) biogenesis, such as Friedreich ataxia linked to frataxin (FXN) deficiency. The pathophysiological relevance of the mitochondrial iron loading and the underlying mechanisms are unknown. Using a mouse model of hepatic FXN deficiency in combination with mice deficient for iron regulatory protein 1 (IRP1), a key regulator of cellular iron metabolism, we show that IRP1 activation in conditions of Fe-S deficiency increases the available cytosolic labile iron pool. Surprisingly, our data indicate that IRP1 activation sustains mitochondrial iron supply and function rather than driving detrimental iron overload. Mitochondrial iron accumulation is shown to depend on mitochondrial dysfunction and heme-dependent upregulation of the mitochondrial iron importer mitoferrin-2. Our results uncover an unexpected protective role of IRP1 in pathological conditions associated with altered Fe-S metabolism.
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Affiliation(s)
- Alain Martelli
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
| | - Stéphane Schmucker
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Laurence Reutenauer
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Jacques R R Mathieu
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Carole Peyssonnaux
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Zoubida Karim
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France
| | - Hervé Puy
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France; AP-HP, Centre Français des Porphyries, Hôpital Louis Mourier, 92701 Colombes, France
| | - Bruno Galy
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Hélène Puccio
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
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23
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Sobin C, Flores-Montoya MG, Gutierrez M, Parisi N, Schaub T. δ-Aminolevulinic acid dehydratase single nucleotide polymorphism 2 (ALAD2) and peptide transporter 2*2 haplotype (hPEPT2*2) differently influence neurobehavior in low-level lead exposed children. Neurotoxicol Teratol 2014; 47:137-45. [PMID: 25514583 DOI: 10.1016/j.ntt.2014.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 12/06/2014] [Accepted: 12/08/2014] [Indexed: 01/06/2023]
Abstract
Delta-aminolevulinic acid dehydratase single nucleotide polymorphism 2 (ALAD2) and peptide transporter haplotype 2*2 (hPEPT2*2) through different pathways can increase brain levels of delta-aminolevulinic acid and are associated with higher blood lead burden in young children. Past child and adult findings regarding ALAD2 and neurobehavior have been inconsistent, and the possible association of hPEPT2*2 and neurobehavior has not yet been examined. Mean blood lead level (BLL), genotype, and neurobehavioral function (fine motor dexterity, working memory, visual attention and short-term memory) were assessed in 206 males and 215 females ages 5.1-11.8years. Ninety-six percent of children had BLLs<5.0μg/dl. After adjusting for covariates (sex, age and mother's level of education) and sibling exclusion (N=252), generalized linear mixed model analyses showed opposite effects for the ALAD2 and hPEPT2*2 genetic variants. Significant effects for ALAD2 were observed only as interactions with BLL and the results suggested that ALAD2 was neuroprotective. As BLL increased, ALAD2 was associated with enhanced visual attention and enhanced working memory (fewer commission errors). Independent of BLL, hPEPT2*2 predicted poorer motor dexterity and poorer working memory (more commission errors). BLL alone predicted poorer working memory from increased omission errors. The findings provided further substantiation that (independent of the genetic variants examined) lowest-level lead exposure disrupted early neurobehavioral function, and suggested that common genetic variants alter the neurotoxic potential of low-level lead. ALAD2 and hPEPT2*2 may be valuable markers of risk, and indicate novel mechanisms of lead-induced neurotoxicity. Longitudinal studies are needed to examine long-term influences of these genetic variants on neurobehavior.
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Affiliation(s)
- Christina Sobin
- College of Health Sciences, Department of Public Health Sciences, University of Texas, El Paso, TX, United States; Border Biomedical Research Center, Toxicology Core, University of Texas, El Paso, TX, United States; Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, United States.
| | - Mayra Gisel Flores-Montoya
- Border Biomedical Research Center, Toxicology Core, University of Texas, El Paso, TX, United States; Department of Psychology, University of Texas, El Paso, TX, United States
| | - Marisela Gutierrez
- Department of Psychology, University of Texas, El Paso, TX, United States
| | - Natali Parisi
- New Mexico State University, Las Cruces, NM, United States
| | - Tanner Schaub
- New Mexico State University, Las Cruces, NM, United States
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24
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Acute intermittent porphyria causes hepatic mitochondrial energetic failure in a mouse model. Int J Biochem Cell Biol 2014; 51:93-101. [DOI: 10.1016/j.biocel.2014.03.032] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/29/2014] [Accepted: 03/31/2014] [Indexed: 01/11/2023]
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25
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Schlessinger A, Khuri N, Giacomini KM, Sali A. Molecular modeling and ligand docking for solute carrier (SLC) transporters. Curr Top Med Chem 2014; 13:843-56. [PMID: 23578028 DOI: 10.2174/1568026611313070007] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/29/2013] [Accepted: 02/01/2013] [Indexed: 12/21/2022]
Abstract
Solute Carrier (SLC) transporters are membrane proteins that transport solutes, such as ions, metabolites, peptides, and drugs, across biological membranes, using diverse energy coupling mechanisms. In human, there are 386 SLC transporters, many of which contribute to the absorption, distribution, metabolism, and excretion of drugs and/or can be targeted directly by therapeutics. Recent atomic structures of SLC transporters determined by X-ray crystallography and NMR spectroscopy have significantly expanded the applicability of structure-based prediction of SLC transporter ligands, by enabling both comparative modeling of additional SLC transporters and virtual screening of small molecules libraries against experimental structures as well as comparative models. In this review, we begin by describing computational tools, including sequence analysis, comparative modeling, and virtual screening, that are used to predict the structures and functions of membrane proteins such as SLC transporters. We then illustrate the applications of these tools to predicting ligand specificities of select SLC transporters, followed by experimental validation using uptake kinetic measurements and other assays. We conclude by discussing future directions in the discovery of the SLC transporter ligands.
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Affiliation(s)
- Avner Schlessinger
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, 1700 4th Street, San Francisco, CA 94158, USA.
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26
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Schulz A, Walther C, Morrison H, Bauer R. In vivo electrophysiological measurements on mouse sciatic nerves. J Vis Exp 2014. [PMID: 24747166 DOI: 10.3791/51181] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Electrophysiological studies allow a rational classification of various neuromuscular diseases and are of help, together with neuropathological techniques, in the understanding of the underlying pathophysiology(1). Here we describe a method to perform electrophysiological studies on mouse sciatic nerves in vivo. The animals are anesthetized with isoflurane in order to ensure analgesia for the tested mice and undisturbed working environment during the measurements that take about 30 min/animal. A constant body temperature of 37 °C is maintained by a heating plate and continuously measured by a rectal thermo probe(2). Additionally, an electrocardiogram (ECG) is routinely recorded during the measurements in order to continuously monitor the physiological state of the investigated animals. Electrophysiological recordings are performed on the sciatic nerve, the largest nerve of the peripheral nervous system (PNS), supplying the mouse hind limb with both motoric and sensory fiber tracts. In our protocol, sciatic nerves remain in situ and therefore do not have to be extracted or exposed, allowing measurements without any adverse nerve irritations along with actual recordings. Using appropriate needle electrodes(3) we perform both proximal and distal nerve stimulations, registering the transmitted potentials with sensing electrodes at gastrocnemius muscles. After data processing, reliable and highly consistent values for the nerve conduction velocity (NCV) and the compound motor action potential (CMAP), the key parameters for quantification of gross peripheral nerve functioning, can be achieved.
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Affiliation(s)
| | | | - Helen Morrison
- Leibniz Institute for Age Research, Fritz Lipmann Institute
| | - Reinhard Bauer
- Institute of Molecular Cell Biology & Center for Sepsis Control and Care (CSCC) Jena University Hospital, Friedrich Schiller University Jena;
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Krieger F, Elflein N, Saenger S, Wirthgen E, Rak K, Frantz S, Hoeflich A, Toyka KV, Metzger F, Jablonka S. Polyethylene glycol-coupled IGF1 delays motor function defects in a mouse model of spinal muscular atrophy with respiratory distress type 1. Brain 2014; 137:1374-93. [DOI: 10.1093/brain/awu059] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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28
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Unzu C, Sampedro A, Mauleón I, González-Aparicio M, Enríquez de Salamanca R, Prieto J, Aragón T, Fontanellas A. Helper-dependent adenoviral liver gene therapy protects against induced attacks and corrects protein folding stress in acute intermittent porphyria mice. Hum Mol Genet 2013; 22:2929-40. [DOI: 10.1093/hmg/ddt148] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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29
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Abstract
Porphyric neuropathy often poses a diagnostic dilemma; it is typically associated with the hepatic porphyrias, characterized by acute life-threatening attacks of neurovisceral symptoms that mimic a range of acute medical and psychiatric conditions. The development of acute neurovisceral attacks is responsive to environmental factors, including drugs, hormones, and diet. This chapter reviews the clinical manifestations, genetics, pathophysiology, and mechanisms of neurotoxicity of the acute hepatic porphyrias. While the etiology of the neurological manifestations in the acute porphyrias remains undefined, the main hypotheses include toxicity of porphyrin precursors and deficiency of heme synthesis. These hypotheses will be discussed with reference to novel experimental models of porphyric neuropathy.
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Affiliation(s)
- Cindy Shin-Yi Lin
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia.
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30
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Abstract
Abstract
The inborn errors of heme biosynthesis, the porphyrias, are 8 genetically distinct metabolic disorders that can be classified as “acute hepatic,” “hepatic cutaneous,” and “erythropoietic cutaneous” diseases. Recent advances in understanding their pathogenesis and molecular genetic heterogeneity have led to improved diagnosis and treatment. These advances include DNA-based diagnoses for all the porphyrias, new understanding of the pathogenesis of the acute hepatic porphyrias, identification of the iron overload-induced inhibitor of hepatic uroporphyrin decarboxylase activity that causes the most common porphyria, porphyria cutanea tarda, the identification of an X-linked form of erythropoietic protoporphyria due to gain-of-function mutations in erythroid-specific 5-aminolevulinate synthase (ALAS2), and new and experimental treatments for the erythropoietic prophyrias. Knowledge of these advances is relevant for hematologists because they administer the hematin infusions to treat the acute attacks in patients with the acute hepatic porphyrias, perform the chronic phlebotomies to reduce the iron overload and clear the dermatologic lesions in porphyria cutanea tarda, and diagnose and treat the erythropoietic porphyrias, including chronic erythrocyte transfusions, bone marrow or hematopoietic stem cell transplants, and experimental pharmacologic chaperone and stem cell gene therapies for congenital erythropoietic protoporphyria. These developments are reviewed to update hematologists on the latest advances in these diverse disorders.
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31
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Balwani M, Desnick RJ. The porphyrias: advances in diagnosis and treatment. Blood 2012; 120:4496-504. [PMID: 22791288 PMCID: PMC3512229 DOI: 10.1182/blood-2012-05-423186] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/07/2012] [Indexed: 02/06/2023] Open
Abstract
The inborn errors of heme biosynthesis, the porphyrias, are 8 genetically distinct metabolic disorders that can be classified as "acute hepatic," "hepatic cutaneous," and "erythropoietic cutaneous" diseases. Recent advances in understanding their pathogenesis and molecular genetic heterogeneity have led to improved diagnosis and treatment. These advances include DNA-based diagnoses for all the porphyrias, new understanding of the pathogenesis of the acute hepatic porphyrias, identification of the iron overload-induced inhibitor of hepatic uroporphyrin decarboxylase activity that causes the most common porphyria, porphyria cutanea tarda, the identification of an X-linked form of erythropoietic protoporphyria due to gain-of-function mutations in erythroid-specific 5-aminolevulinate synthase (ALAS2), and new and experimental treatments for the erythropoietic porphyrias. Knowledge of these advances is relevant for hematologists because they administer the hematin infusions to treat the acute attacks in patients with the acute hepatic porphyrias, perform the chronic phlebotomies to reduce the iron overload and clear the dermatologic lesions in porphyria cutanea tarda, and diagnose and treat the erythropoietic porphyrias, including chronic erythrocyte transfusions, bone marrow or hematopoietic stem cell transplants, and experimental pharmacologic chaperone and stem cell gene therapies for congenital erythropoietic protoporphyria. These developments are reviewed to update hematologists on the latest advances in these diverse disorders.
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Affiliation(s)
- Manisha Balwani
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA
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Schlessinger A, Wittwer MB, Dahlin A, Khuri N, Bonomi M, Fan H, Giacomini KM, Sali A. High selectivity of the γ-aminobutyric acid transporter 2 (GAT-2, SLC6A13) revealed by structure-based approach. J Biol Chem 2012; 287:37745-56. [PMID: 22932902 DOI: 10.1074/jbc.m112.388157] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The solute carrier 6 (SLC6) is a family of ion-dependent transporters that mediate uptake into the cell of osmolytes such as neurotransmitters and amino acids. Four SLC6 members transport GABA, a key neurotransmitter that triggers inhibitory signaling pathways via various receptors (e.g., GABA(A)). The GABA transporters (GATs) regulate the concentration of GABA available for signaling and are thus targeted by a variety of anticonvulsant and relaxant drugs. Here, we characterize GAT-2, a transporter that plays a role in peripheral GABAergic mechanisms, by constructing comparative structural models based on crystallographic structures of the leucine transporter LeuT. Models of GAT-2 in two different conformations were constructed and experimentally validated, using site-directed mutagenesis. Computational screening of 594,166 compounds including drugs, metabolites, and fragment-like molecules from the ZINC database revealed distinct ligands for the two GAT-2 models. 31 small molecules, including high scoring compounds and molecules chemically related to known and predicted GAT-2 ligands, were experimentally tested in inhibition assays. Twelve ligands were found, six of which were chemically novel (e.g., homotaurine). Our results suggest that GAT-2 is a high selectivity/low affinity transporter that is resistant to inhibition by typical GABAergic inhibitors. Finally, we compared the binding site of GAT-2 with those of other SLC6 members, including the norepinephrine transporter and other GATs, to identify ligand specificity determinants for this family. Our combined approach may be useful for characterizing interactions between small molecules and other membrane proteins, as well as for describing substrate specificities in other protein families.
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Affiliation(s)
- Avner Schlessinger
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94158, USA
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Hift RJ, Thunell S, Brun A. Drugs in porphyria: From observation to a modern algorithm-based system for the prediction of porphyrogenicity. Pharmacol Ther 2011; 132:158-69. [DOI: 10.1016/j.pharmthera.2011.06.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 06/01/2011] [Indexed: 02/06/2023]
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Kuo HC, Huang CC, Chu CC, Lee MJ, Chuang WL, Wu CL, Wu T, Ning HC, Liu CY. Neurological complications of acute intermittent porphyria. Eur Neurol 2011; 66:247-52. [PMID: 21986212 DOI: 10.1159/000330683] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 06/27/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND Acute intermittent porphyria (AIP) is an inherited disorder of heme biosynthesis, the clinical manifestations of which are incompletely understood. In this report, we describe 12 cases of AIP, focusing on the neurological manifestations. METHODS Twelve patients were diagnosed with AIP on the basis of characteristic clinical findings, erythrocyte porphobilinogen deaminase (PBGD) activity, and molecular genetics. Central and peripheral nervous system manifestations were noted, and electrophysiological and radiological studies performed. Potential precipitating factors were recorded. RESULTS Eleven PBGD gene mutations were identified in 12 patients. Nine patients experienced neurological symptoms involving the central nervous system (consciousness disturbance, n = 8; convulsion/seizure, n = 4; behavior change, n = 1), while 7 patients experienced peripheral neuropathies (motor paresis, n = 7; impairment of bulbar or respiratory function, n = 4). The electrophysiological and electroencephalographic findings were consistent with the neurological symptoms of AIP. Urinary PBG and δ-aminolevulinic acid levels were elevated in all patients. PBGD enzyme activity levels were below normal in all patients. Eight patients had documented exposure to porphyrogenic agents. CONCLUSIONS Our detailed description of a relatively large number of cases of AIP may help clinicians to recognize this often difficult-to-diagnose disorder.
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Affiliation(s)
- Hung-Chou Kuo
- Department of Neurology, Chang Gung Memorial Hospital at Linkou and College of Medicine, Chang Gung University, Taiwan, ROC.
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Lin CSY, Lee MJ, Park SB, Kiernan MC. Purple pigments: the pathophysiology of acute porphyric neuropathy. Clin Neurophysiol 2011; 122:2336-44. [PMID: 21855406 DOI: 10.1016/j.clinph.2011.07.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 07/07/2011] [Accepted: 07/08/2011] [Indexed: 10/15/2022]
Abstract
The porphyrias are inherited metabolic disorders arising from disturbance in the haem biosynthesis pathway. The neuropathy associated with acute intermittent porphyria (AIP) occurs due to mutation involving the enzyme porphobilinogen deaminase (PBGD) and is characterised by motor-predominant features. Definitive diagnosis often encompasses a combination of biochemical, enzyme analysis and genetic testing, with clinical neurophysiological findings of a predominantly motor axonal neuropathy. Symptomatic and supportive treatment are the mainstays during an acute attack. If administered early, intravenous haemin may prevent progression of neuropathy. While the pathophysiology of AIP neuropathy remains unclear, axonal dysfunction appears intrinsically linked to the effects of neural energy deficits acquired through haem deficiency coupled to the neurotoxic effects of porphyrin precursors. The present review will provide an overview of AIP neuropathy, including discussion of recent advances in understanding developed through neurophysiological approaches that have further delineated the pathophysiology of axonal degeneration.
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Affiliation(s)
- Cindy S-Y Lin
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia.
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Zhang J, Yasuda M, Desnick RJ, Balwani M, Bishop D, Yu C. A LC-MS/MS method for the specific, sensitive, and simultaneous quantification of 5-aminolevulinic acid and porphobilinogen. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:2389-96. [PMID: 21783436 DOI: 10.1016/j.jchromb.2011.06.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/18/2011] [Accepted: 06/24/2011] [Indexed: 11/24/2022]
Abstract
Accurate determinations of 5-aminolevulinic acid (ALA) and porphobilinogen (PBG) in physiologic fluids are required for the diagnosis and therapeutic monitoring of acute porphyrias. Current colorimetric methods are insensitive and over-estimate ALA and PBG due to poor specificity, while LC-MS/MS methods increase sensitivity, but have limited matrices. An LC-MS/MS method was developed to simultaneously determine ALA and PBG concentrations in fluids or tissues which were solid phase extracted, butanol derivatized, and quantitated by selective reaction monitoring using (13)C(5), (15)N-ALA and 2,4-(13)C(2)-PBG internal standards. ALA was separated from interfering compounds on a reverse phase C8-column. For ALA and PBG, the matrix effects (87.3-105%) and process efficiencies (77.6-97.8% and 37.2-41.6%, respectively) were acceptable in plasma and urine matrices. The assay was highly sensitive for ALA and PBG (LLOQ=0.05 μM with 25 μL urine or 100 μL plasma), and required ∼4 h from extraction to results. ALA and PBG accuracy ranged from 88.2 to 110% (n=10); intra- and inter-assay coefficients of variations were <10% for urine and plasma. In clinical applications, patients with mutation-confirmed acute porphyrias had normal to slightly increased urinary ALA and PBG levels when asymptomatic, and high levels during acute attacks, which decreased with hemin therapy. In AIP mice, baseline ALA and PBG levels in urine, plasma, and liver were increased after phenobarbital induction 28-/63-, 42-/266-, and 13-/316-fold, respectively. This LC-MS/MS method is rapid, specific, highly sensitive, accurate, and simultaneously measures ALA and PBG in urine, plasma, and tissues permitting porphyria clinical diagnoses, therapeutic monitoring, and research.
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Affiliation(s)
- Jinglan Zhang
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, Fifth Avenue at 100th Street, New York, NY 10029, USA
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Stacpoole PW. The dichloroacetate dilemma: environmental hazard versus therapeutic goldmine--both or neither? ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:155-8. [PMID: 20920954 PMCID: PMC3040600 DOI: 10.1289/ehp.1002554] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 10/04/2010] [Indexed: 05/23/2023]
Abstract
BACKGROUND Dichloroacetate (DCA) is known to environmental scientists as a by-product of water chlorination and as a metabolite of industrial solvents, including Superfund chemicals. In contrast, DCA is studied by clinical investigators for its therapeutic potential in several life-threatening conditions, including genetic mitochondrial diseases, pulmonary arterial hypertension, and cancer. Thus, DCA holds an almost unique position at the interface between environmental science and allopathic medicine. OBJECTIVE I critically reviewed laboratory and clinical pharmacological research on DCA to address questions about the current and future status of DCA in relation to human health. DISCUSSION Recent information on the clinical toxicogenetics of DCA is interpreted particularly in light of its use as an investigational drug. Adverse effects from chronic DCA exposure have been identified in several target organs in animals. However, in humans, toxicity has so far been limited to reversible effects on the nervous system and liver. DCA is primarily biotransformed to glyoxylate by the bifunctional enzyme glutathione transferase zeta1 and maleylacetoacetate isomerase (GSTz1/MAAI), which also catalyzes the penultimate step in the phenylalanine and tyrosine catabolic pathway. DCA is a suicide inhibitor of GSTz1/MAAI, which can result in delayed plasma clearance of DCA and the accumulation of potentially toxic tyrosine intermediates. Age and GSTz1/MAAI haplotype can markedly affect the toxicokinetics of DCA in humans and rodents. CONCLUSIONS I have defined new potential avenues of research that focus on discrete human populations that may be at increased health risk or that may receive increased health benefit from chronic exposure to DCA at both environmentally and clinically relevant concentrations.
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Affiliation(s)
- Peter W Stacpoole
- Department of Medicine, Division of Endocrinology and Metabolism, College of Medicine, University of Florida, Gainesville, Florida 32610, USA.
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Unzu C, Sampedro A, Mauleón I, Alegre M, Beattie SG, de Salamanca RE, Snapper J, Twisk J, Petry H, González-Aseguinolaza G, Artieda J, Rodríguez-Pena MS, Prieto J, Fontanellas A. Sustained enzymatic correction by rAAV-mediated liver gene therapy protects against induced motor neuropathy in acute porphyria mice. Mol Ther 2010; 19:243-50. [PMID: 20877347 DOI: 10.1038/mt.2010.210] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Acute intermittent porphyria (AIP) is characterized by a hereditary deficiency of hepatic porphobilinogen deaminase (PBGD) activity. Clinical features are acute neurovisceral attacks accompanied by overproduction of porphyrin precursors in the liver. Recurrent life-threatening attacks can be cured only by liver transplantation. We developed recombinant adeno-associated virus (rAAV) vectors expressing human PBGD protein driven by a liver-specific promoter to provide sustained protection against induced attacks in a predictive model for AIP. Phenobarbital injections in AIP mice induced porphyrin precursor accumulation, functional block of nerve conduction, and progressive loss of large-caliber axons in the sciatic nerve. Hepatocyte transduction showed no gender variation after rAAV2/8 injection, while rAAV2/5 showed lower transduction efficiency in females than males. Full protection against induced phenobarbital-attacks was achieved in animals showing over 10% of hepatocytes expressing high amounts of PBGD. More importantly, sustained hepatic expression of hPBGD protected against loss of large-caliber axons in the sciatic nerve and disturbances in nerve conduction velocity as induced by recurrent phenobarbital administrations. These data show for the first time that porphyrin precursors generated in the liver interfere with motor function. rAAV2/5-hPBGD vector can be produced in sufficient quantity for an intended gene therapy trial in patients with recurrent life-threatening porphyria attacks.
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Affiliation(s)
- Carmen Unzu
- Gene Therapy and Hepatology Area, Centre for Applied Medical Research, University of Navarra, Pamplona, Spain
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Gawlik KI, Akerlund M, Carmignac V, Elamaa H, Durbeej M. Distinct roles for laminin globular domains in laminin alpha1 chain mediated rescue of murine laminin alpha2 chain deficiency. PLoS One 2010; 5:e11549. [PMID: 20657839 PMCID: PMC2906511 DOI: 10.1371/journal.pone.0011549] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 06/21/2010] [Indexed: 11/24/2022] Open
Abstract
Background Laminin α2 chain mutations cause congenital muscular dystrophy with dysmyelination neuropathy (MDC1A). Previously, we demonstrated that laminin α1 chain ameliorates the disease in mice. Dystroglycan and integrins are major laminin receptors. Unlike laminin α2 chain, α1 chain binds the receptors by separate domains; laminin globular (LG) domains 4 and LG1-3, respectively. Thus, the laminin α1 chain is an excellent tool to distinguish between the roles of dystroglycan and integrins in the neuromuscular system. Methodology/Principal Findings Here, we provide insights into the functions of laminin α1LG domains and the division of their roles in MDC1A pathogenesis and rescue. Overexpression of laminin α1 chain that lacks the dystroglycan binding LG4-5 domains in α2 chain deficient mice resulted in prolonged lifespan and improved health. Importantly, diaphragm and heart muscles were corrected, whereas limb muscles were dystrophic, indicating that different muscles have different requirements for LG4-5 domains. Furthermore, the regenerative capacity of the skeletal muscle did not depend on laminin α1LG4-5. However, this domain was crucial for preventing apoptosis in limb muscles, essential for myelination in peripheral nerve and important for basement membrane assembly. Conclusions/Significance These results show that laminin α1LG domains and consequently their receptors have disparate functions in the neuromuscular system. Understanding these interactions could contribute to design and optimization of future medical treatment for MDC1A patients.
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Affiliation(s)
- Kinga I Gawlik
- Department of Experimental Medical Science, Muscle Biology Unit, University of Lund, Lund, Sweden
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Xia RH, Yosef N, Ubogu EE. Dorsal caudal tail and sciatic motor nerve conduction studies in adult mice: technical aspects and normative data. Muscle Nerve 2010; 41:850-6. [PMID: 20151466 DOI: 10.1002/mus.21588] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mice provide an important tool to investigate human neuromuscular disorders. The variability of electrophysiological techniques limits direct comparison between studies. The purpose of this study was to establish normative motor nerve conduction data in adult mice. The dorsal caudal tail nerve and sciatic nerve motor conduction studies were performed bilaterally on restrained anesthetized adult mice. The means and standard deviations for each electrophysiological parameter were determined in normal mice. Data were compared with inflammatory demyelinating polyneuropathy mice to determine whether these parameters discriminate between normal and abnormal peripheral nerves. Normal adult mice had a distal latency of 0.89 (+/-0.17) ms and 0.75 (+/-0.09) ms, distal compound motor unit action potential amplitude of 13.2 (+/-5.9) mV and 28.1 (+/-8.3) mV, and conduction velocity of 74.6 (+/-9.0) m/s and 76.5 (+/-8.3) m/s, respectively. These data were validated by the finding of statistically significant differences in several electrophysiological parameters that compared normal and polyneuropathy-affected mice. A standardized method for motor nerve conduction studies and associated normative data in mice should facilitate comparisons of disease severity and response to treatment between studies that use similar models. This would assist in the process of translational therapeutic drug design in neuromuscular disorders.
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Affiliation(s)
- Robin H Xia
- Neuromuscular Immunopathology Research Laboratory, Department of Neurology, Baylor College of Medicine, One Baylor Plaza, Mailstop NB 302, Houston, Texas 77030-3411, USA
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Dwyer BE, Stone ML, Zhu X, Perry G, Smith MA. Heme deficiency in Alzheimer's disease: a possible connection to porphyria. J Biomed Biotechnol 2010; 2006:24038. [PMID: 17047301 PMCID: PMC1559910 DOI: 10.1155/jbb/2006/24038] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Mechanisms that cause Alzheimer's disease (AD), an invariably
fatal neurodegenerative disease, are unknown. Important recent
data indicate that neuronal heme deficiency may
contribute to AD pathogenesis. If true, factors that contribute to
the intracellular heme deficiency could potentially alter the
course of AD. The porphyrias are metabolic disorders characterized
by enzyme deficiencies in the heme biosynthetic pathway. We
hypothesize that AD may differ significantly in individuals
possessing the genetic trait for an acute hepatic porphyria. We
elaborate on this hypothesis and briefly review the
characteristics of the acute hepatic porphyrias that may be
relevant to AD. We note the proximity of genes encoding enzymes of
the heme biosynthesis pathway to genetic loci linked to sporadic,
late-onset AD. In addition, we suggest that identification of
individuals carrying the genetic trait for acute porphyria may
provide a unique resource for investigating AD pathogenesis and
inform treatment and management decisions.
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Affiliation(s)
- Barney E. Dwyer
- Research Service (151), VA Medical & Regional Office
Center, White River Junction, VT 05009, USA
- Department of Medicine (Neurology), Dartmouth Medical
School, Hanover, NH 03755, USA
- *Barney E. Dwyer:
| | - Meghan L. Stone
- Research Service (151), VA Medical & Regional Office
Center, White River Junction, VT 05009, USA
| | - Xiongwei Zhu
- Institute of Pathology, Case Western Reserve
University, Cleveland, OH 44106, USA
| | - George Perry
- Institute of Pathology, Case Western Reserve
University, Cleveland, OH 44106, USA
| | - Mark A. Smith
- Institute of Pathology, Case Western Reserve
University, Cleveland, OH 44106, USA
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Unzu C, Sampedro A, Mauleón I, Vanrell L, Dubrot J, de Salamanca RE, González-Aseguinolaza G, Melero I, Prieto J, Fontanellas A. Porphobilinogen deaminase over-expression in hepatocytes, but not in erythrocytes, prevents accumulation of toxic porphyrin precursors in a mouse model of acute intermittent porphyria. J Hepatol 2010; 52:417-24. [PMID: 19815305 DOI: 10.1016/j.jhep.2009.09.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/01/2009] [Accepted: 07/05/2009] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Acute intermittent porphyria (AIP) is characterized by hepatic porphobilinogen deaminase (PBGD) deficiency resulting in a marked overproduction of presumably toxic porphyrin precursors. Our study aimed to assess the protective effects of bone marrow transplantation or PBGD gene transfer into the liver against phenotypic manifestations of acute porphyria attack induced in an AIP murine model. METHODS Lethally irradiated AIP mice were intravenously injected with 5x10(6) nucleated bone marrow cells from wild type or AIP donor mice. To achieve liver gene transfer, AIP mice received via hydrodynamic injection plasmids expressing human PBGD or luciferase, driven by a liver-specific promoter. RESULTS Erythrocyte PBGD activity increased 2.4-fold in AIP mice receiving bone marrow cells from normal animals. Nevertheless, phenobarbital administration in these mice reproduced key features of acute attacks, such as massively increased urinary porphyrin precursor excretion and decreased motor coordination. Hepatic PBGD activity increased 2.2-fold after hydrodynamic injection of therapeutic plasmid. Mice injected with the luciferase control plasmid showed a high excretion of porphyrin precursors after phenobarbital administration whereas just a small increase was observed in AIP mice injected with the PBGD plasmid. Furthermore, motor disturbance was almost completely abolished in AIP mice treated with the therapeutic plasmid. CONCLUSIONS PBGD deficiency in erythroid tissue is not associated with phenotypic manifestations of acute porphyria. In contrast, PBGD over-expression in hepatocytes, albeit in a low proportion, reduced precursor accumulation, which is the hallmark of acute porphyric attacks. Liver-directed gene therapy might offer an alternative to liver transplantation applicable in patients with severe and recurrent manifestations.
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Affiliation(s)
- Carmen Unzu
- Division of Gene Therapy and Hepatology, Center for Applied Medical Research, University of Navarra, Avda. Pio XII 55, Pamplona, Spain
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AAV8-mediated gene therapy prevents induced biochemical attacks of acute intermittent porphyria and improves neuromotor function. Mol Ther 2009; 18:17-22. [PMID: 19861948 DOI: 10.1038/mt.2009.250] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Acute intermittent porphyria (AIP), an autosomal dominant hepatic porphyria due to half-normal hydroxymethylbilane synthase (HMB-synthase) activity, is manifested by life-threatening acute neurological attacks that are precipitated by factors that induce heme biosynthesis. The acute attacks are currently treated with intravenous hemin, but a more continuous therapy is needed, particularly for patients experiencing frequent attacks. Thus, a recombinant AAV8-based serotype vector expressing murine HMB-synthase driven by liver-specific regulatory elements was generated and its effectiveness to prevent the biochemical induction of an acute attack was evaluated in an AIP mouse model. Intraperitoneal administration of the adeno-associated viral (AAV) vector resulted in a rapid and dose-dependent increase of HMB-synthase activity that was restricted to the liver. Stable expression of hepatic HMB-synthase was achieved and wild-type or greater levels were sustained for 36 weeks. When heme synthesis was periodically induced by a series of phenobarbital injections, the treated mice did not accumulate urinary delta-aminolevulinic acid (ALA) or porphobilinogen (PBG), indicating that the expressed enzyme was functional in vivo and prevented induction of the acute attack. Further, rotarod performance and footprint analyses improved significantly. Thus, liver-directed gene therapy provided successful long-term correction of the hepatic metabolic abnormalities and improved neuromotor function in the murine model of human AIP.
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Sobin C, Gutierrez M, Alterio H. Polymorphisms of delta-aminolevulinic acid dehydratase (ALAD) and peptide transporter 2 (PEPT2) genes in children with low-level lead exposure. Neurotoxicology 2009; 30:881-7. [PMID: 19723536 DOI: 10.1016/j.neuro.2009.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 07/22/2009] [Accepted: 08/25/2009] [Indexed: 12/01/2022]
Abstract
Low-level lead exposure during early childhood has long been associated with altered neurocognitive development and diminished cognitive functions. Over nine thousand U.S. industrial facilities annually emit significant amounts of lead, creating exposure risk particularly for minority children. The mechanisms by which low-level lead exerts neurotoxic effects are poorly understood. Once absorbed, the only intervention is source removal, thus primary prevention is key. Genetic biomarkers could provide an efficient means of identifying children at greatest risk. Common functional variants of genes that alter lead's neurotoxic potential have been identified and include delta-aminolevulinic acid dehydratase (ALAD(2)) and peptide transporter 2 (PEPT2*2). These polymorphisms have not been examined previously in Hispanic minority samples, or with regard to lowest level lead exposure. In 116 children of Mexican-American/Hispanic descent residing in zip codes previously designated as "high risk" for lead exposure (mean age=8.1, S.D.=1.9), blood lead level was measured at three time points over a 3-month period and averaged. DNA extraction was completed using buccal swab samples. The frequencies of the ALAD(2) and PEPT2*2 polymorphisms observed in this sample closely approximated those previously reported for Anglo, European and Asian samples. As compared to children heterozygous for the PEPT2*2 polymorphism, and without the PEPT2*2 polymorphism, the geometric mean blood lead level of children homozygous for the PEPT2*2 polymorphism was significantly higher. In contrast to past studies, mean blood lead level of children heterozygous and homozygous for the ALAD2 polymorphism in this sample did not differ from that of children without the ALAD2 polymorphism. Higher blood lead burden in children with the PEPT2*2 mutation may suggest that this common genetic variant is a biomarker of increased vulnerability to the neurotoxic effects of lowest level lead exposure.
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Affiliation(s)
- Christina Sobin
- Border Biomedical Research Center, Toxicology Project and Laboratory of Neurocognitive Genetics and Developmental Neurocognition, Department of Psychology, University of Texas, El Paso, El Paso, TX 79968, USA.
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Ventura P, Cappellini MD, Rocchi E. The acute porphyrias: a diagnostic and therapeutic challenge in internal and emergency medicine. Intern Emerg Med 2009; 4:297-308. [PMID: 19479318 DOI: 10.1007/s11739-009-0261-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Accepted: 04/29/2009] [Indexed: 10/20/2022]
Abstract
The porphyrias are a heterogeneous group of metabolic diseases resulting from a variable catalytic defect of one of the eight enzymes involved in the heme biosynthesis pathway; they are mostly inherited diseases, but in some circumstances the metabolic disturbance may be acquired. The specific patterns of tissue overproduction (and hence accumulation and excretion) of toxic heme precursors, associated with each enzymatic deficiency, are responsible for the characteristic biochemical and clinical features of each of these diseases. Moreover, even in the presence of a specific inherited enzymatic defect, many different environmental factors (such as drugs, calorie restriction, hormones, sunlight exposition, infections, etc.) often play a key role in triggering the clinical expression of the various forms of porphyrias. The porphyrias are often misdiagnosed diseases, due their multiform clinical manifestations, able to mimic many other more common diseases. For this reason, many different specialists, such as surgeons, psychiatrists, gastroenterologists, neurologists, emergency physicians and dermatologists may be variably involved in the diagnostic process, especially for the forms presenting with acute and life-threatening clinical features. According to the clinical features, the porphyrias can be classified into neuropsychiatric (characterized by neurovisceral crises involving autonomic and central nervous system but also the liver and the kidney with possible consequences in terms of neurological, psychic, cardiac, respiratory, liver and kidney functions), dermatological (mostly presenting with cutaneous lesions due to photosensitivity), and mixed forms. From a strictly clinical point of view, porphyrias presenting with neurovisceral attacks are also referred as acute porphyrias: they are the object of the present review. An accurate diagnosis of acute porphyria requires knowledge and the use of correct diagnostic tools, and it is mandatory to provide a more appropriate therapeutic approach and prevent the use of potentially unsafe drugs, able to severely precipitate these diseases, especially in the presence of life-threatening symptoms. To date, availability of a relatively stable haem preparation (haem arginate) has significantly improved the treatment outcome of acute porphyric attacks, so the knowledge about the diagnosis and the management of these diseases may be relevant for physicians working in internal medicine, neurology and emergency units.
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Affiliation(s)
- Paolo Ventura
- Department of Medicines and Medical Specialties, Ambulatorio delle Porfirie e delle Malattie da Disturbo del Metabolismo degli Aminoacidi, University of Modena and Reggio Emilia, Policlinico of Modena, Largo del Pozzo 71, Modena, Italy.
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Ban DX, Kong XH, Feng SQ, Ning GZ, Chen JT, Guo SF. Intraspinal cord graft of autologous activated Schwann cells efficiently promotes axonal regeneration and functional recovery after rat's spinal cord injury. Brain Res 2008; 1256:149-61. [PMID: 19103176 DOI: 10.1016/j.brainres.2008.11.098] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/25/2008] [Accepted: 11/26/2008] [Indexed: 01/03/2023]
Abstract
Basic research in spinal cord injury (SCI) has made great strides in recent years, and some new insights and strategies have been applied in promoting effective axonal regrowth and sprouting. However, a relatively safe and efficient transplantation technique remains undetermined. This study, therefore, was aimed to address a question of how to graft Schwann cells to achieve the best possible therapeutic effects. To clarify the issue, the rats were subjected to spinal cord injury at T10. Autologous activated Schwann cells (AASCs) were obtained by prior ligation of saphenous nerve and subsequently isolated and purified in vitro and then grafted into spinal cord-injured rats via three different routes (group I: intravenous, group II: intrathecal and group III: intraspinal cord). Neurologic function was serially evaluated by Basso, Beattie, Bresnahan locomotor rating scale and footprint analysis. We also evaluated the migration of the transplanted cells at 2 weeks after transplantation. Using biotinylated dextran amine (BDA) anterograde tracing, we demonstrated that more regenerative axons of corticospinal tract (CST) surrounding the injured cavity in group III than those in the other two groups, and we also confirmed it further by quantitative analysis. The microenvironment surrounding the injured spinal cord has been improved to the greatest extent in group III, as determined by immunohistological staining. Relatively complete myelin sheaths and more neurofilaments in axons were found in groups II and III than those in group I under electron microscopy. The results showed that intraspinal cord injection of AASCs promoted recovery of hindlimb locomotor function of injured rats more efficiently than the other grafting routes. In addition, intact myelin sheaths and sufficient neurofilaments in axons were not adequate for full functional recovery after SCI, suggesting that reestablishment of normal synaptic connection is indispensable. The findings in this study strongly suggest that transplantation of AASCs directly into the spinal cord may be one of the promising candidates for potential scaffold for injured spinal cord, and such strategy of transplantation of AASCs could be hopeful to treat patients with SCI.
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Affiliation(s)
- De-Xiang Ban
- Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin Heping District Anshan Road 154, Tianjin 300052, PR China
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Kamal MA, Keep RF, Smith DE. Role and relevance of PEPT2 in drug disposition, dynamics, and toxicity. Drug Metab Pharmacokinet 2008; 23:236-42. [PMID: 18762710 DOI: 10.2133/dmpk.23.236] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Pept2 knockout mice are an important tool to evaluate the evolving role and relevance of this proton-coupled oligopeptide transporter beyond drug disposition, where the transporter also modulates the pharmacodynamic and toxicodynamic effects of drug substrates. Our in vivo studies with glycylsarcosine in Pept2 knockout mice have established "proof of concept" that PEPT2 can have a significant effect on dipeptide disposition. Subsequent studies with the aminocephalosporin antibiotic cefadroxil have shown relevance to pharmacology and infectious disease. Finally, studies with the endogenous peptidomimetic 5-aminolevulinic acid have demonstrated relevance to toxicology in the framework of porphyria- and lead-induced neurotoxicity. These studies have consistently demonstrated the dual action of PEPT2 with respect to its apical localization in choroid plexus epithelium and kidney in: 1) effluxing substrates from CSF into choroid plexus, thereby affecting regional pharmacokinetics in brain; and 2) reabsorbing substrates from renal tubular fluid into proximal tubules, thereby affecting systemic pharmacokinetics and exposure. Moreover, these studies have shown that the regional effect of PEPT2 in limiting substrate concentrations in the CSF is more dramatic than its effect in increasing systemic exposure. In the case of 5-aminolevulinic acid, such regional modulation of drug disposition translates directly into significant changes in neurotoxicity.
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Affiliation(s)
- Mohamed A Kamal
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109-5633, USA
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Felitsyn N, McLeod C, Shroads AL, Stacpoole PW, Notterpek L. The heme precursor delta-aminolevulinate blocks peripheral myelin formation. J Neurochem 2008; 106:2068-79. [PMID: 18665889 DOI: 10.1111/j.1471-4159.2008.05552.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Delta-aminolevulinic acid (delta-ALA) is a heme precursor implicated in neurological complications associated with porphyria and tyrosinemia type I. Delta-ALA is also elevated in the urine of animals and patients treated with the investigational drug dichloroacetate (DCA). We postulated that delta-ALA may be responsible, in part, for the peripheral neuropathy observed in subjects receiving DCA. To test this hypothesis, myelinating cocultures of Schwann cells and sensory neurons were exposed to delta-ALA (0.1-1 mM) and analyzed for the expression of neural proteins and lipids and markers of oxidative stress. Exposure of myelinating samples to delta-ALA is associated with a pronounced reduction in the levels of myelin-associated lipids and proteins, including myelin protein zero and peripheral myelin protein 22. We also observed an increase in protein carbonylation and the formation of hydroxynonenal and malondialdehyde after treatment with delta-ALA. Studies of isolated Schwann cells and neurons indicate that glial cells are more vulnerable to this pro-oxidant than neurons, based on a selective decrease in the expression of mitochondrial respiratory chain proteins in glial, but not in neuronal, cells. These results suggest that the neuropathic effects of delta-ALA are attributable, at least in part, to its pro-oxidant properties which damage myelinating Schwann cells.
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Affiliation(s)
- Natalia Felitsyn
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA
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Hu Y, Shen H, Keep RF, Smith DE. Peptide transporter 2 (PEPT2) expression in brain protects against 5-aminolevulinic acid neurotoxicity. J Neurochem 2007; 103:2058-65. [PMID: 17854384 DOI: 10.1111/j.1471-4159.2007.04905.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The proton-coupled oligopeptide transporter PEPT2 (or SLC15A2) is the major protein involved in the reclamation of peptide-bound amino acids and peptide-like drugs in kidney. PEPT2 is also important in effluxing peptides and peptidomimetics from CSF at the choroid plexus, thereby limiting their exposure in brain. In this study, we report a neuroprotective role for PEPT2 in modulating the toxicity of a heme precursor, 5-aminolevulinic acid (5-ALA). Our findings demonstrate that in PEPT2-deficient mice, 5-ALA administration results in reduced survivability, a worsening of neuromuscular dysfunction, and CSF concentrations of substrate that are 8-30 times higher than that in wild-type control animals. The ability of PEPT2 to limit 5-ALA exposure in CSF suggests that it may also have relevance as a secondary genetic modifier of conditions (such as acute hepatic porphyrias and lead poisoning) in which 5-ALA metabolism is altered and in which 5-ALA toxicity is important.
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Affiliation(s)
- Yongjun Hu
- Department of Pharmaceutical Sciences and Upjohn Center for Clinical Pharmacology, The University of Michigan, Ann Arbor, Michigan, USA
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