1
|
Balogun O, Nejak-Bowen K. The Hepatic Porphyrias: Revealing the Complexities of a Rare Disease. Semin Liver Dis 2023; 43:446-459. [PMID: 37973028 DOI: 10.1055/s-0043-1776760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The porphyrias are a group of metabolic disorders that are caused by defects in heme biosynthesis pathway enzymes. The result is accumulation of heme precursors, which can cause neurovisceral and/or cutaneous photosensitivity. Liver is commonly either a source or target of excess porphyrins, and porphyria-associated hepatic dysfunction ranges from minor abnormalities to liver failure. In this review, the first of a three-part series, we describe the defects commonly found in each of the eight enzymes involved in heme biosynthesis. We also discuss the pathophysiology of the hepatic porphyrias in detail, covering epidemiology, histopathology, diagnosis, and complications. Cellular consequences of porphyrin accumulation are discussed, with an emphasis on oxidative stress, protein aggregation, hepatocellular cancer, and endothelial dysfunction. Finally, we review current therapies to treat and manage symptoms of hepatic porphyria.
Collapse
Affiliation(s)
- Oluwashanu Balogun
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Kari Nejak-Bowen
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
- Pittsburgh Liver Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| |
Collapse
|
2
|
Kang X, Shimada S, Miyahara H, Higuchi K, Mori M. BALB.NCT-Cpox is a unique mouse model of hereditary coproporphyria. Mol Genet Metab Rep 2023; 35:100964. [PMID: 36967721 PMCID: PMC10036863 DOI: 10.1016/j.ymgmr.2023.100964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023] Open
Abstract
In humans, mutations in the coproporphyrinogen oxidase (CPOX) gene can result in hereditary coproporphyria (HCP), characterized by high levels of coproporphyrin excretion in the urine and feces, as well as acute neurovisceral and chronic cutaneous manifestations. Appropriate animal models for comprehending the precise pathogenesis mechanism of HCP have not been reported that show similarities in terms of gene mutation, reduced CPOX activity, excess coproporphyrin accumulation, and clinical symptoms. As previously discovered, the BALB.NCT-Cpox nct mouse carries a hypomorphic mutation in the Cpox gene. Due to the mutation, BALB.NCT-Cpox nct had a drastic increase in coproporphyrin in the blood and liver persistently from a young age. In this study, we found that BALB.NCT-Cpox nct mice manifested HCP symptoms. Similar to HCP patients, BALB.NCT-Cpox nct excreted an excessive amount of coproporphyrin and porphyrin precursors in the urine and displayed neuromuscular symptoms, such as a lack of grip strength and impaired motor coordination. Male BALB.NCT-Cpox nct had nonalcoholic steatohepatitis (NASH)-like liver pathology and sclerodermatous skin pathology. A portion of male mice had liver tumors as well, whereas female BALB.NCT-Cpox nct lacked these hepatic and cutaneous pathologies. In addition, we discovered that BALB.NCT-Cpox nct exhibited microcytic anemia. These results indicate that BALB.NCT-Cpox nct mice serve as the suitable animal model to help gain insight into the pathogenesis and therapy of HCP.
Collapse
|
3
|
Yasuda M, Chen B, Desnick RJ. Recent advances on porphyria genetics: Inheritance, penetrance & molecular heterogeneity, including new modifying/causative genes. Mol Genet Metab 2019; 128:320-331. [PMID: 30594473 PMCID: PMC6542720 DOI: 10.1016/j.ymgme.2018.11.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/16/2022]
Abstract
The inborn errors of heme biosynthesis, the Porphyrias, include eight major disorders resulting from loss-of-function (LOF) or gain-of-function (GOF) mutations in eight of the nine heme biosynthetic genes. The major sites of heme biosynthesis are the liver and erythron, and the underlying pathophysiology of each of these disorders depends on the unique biochemistry, cell biology, and genetic mechanisms in these tissues. The porphyrias are classified into three major categories: 1) the acute hepatic porphyrias (AHPs), including Acute Intermittent Porphyria (AIP), Hereditary Coproporphyria (HCP), Variegate Porphyria (VP), and 5-Aminolevlulinic Acid Dehydratase Deficient Porphyria (ADP); 2) a hepatic cutaneous porphyria, Porphyria Cutanea Tarda (PCT); and 3) the cutaneous erythropoietic porphyrias, Congenital Erythropoietic Porphyria (CEP), Erythropoietic Protoporphyria (EPP), and X-Linked Protoporphyria (XLP). Their modes of inheritance include autosomal dominant with markedly decreased penetrance (AIP, VP, and HCP), autosomal recessive (ADP, CEP, and EPP), or X-linked (XLP), as well as an acquired sporadic form (PCT). There are severe homozygous dominant forms of the three AHPs. For each porphyria, its phenotype, inheritance pattern, unique genetic principles, and molecular genetic heterogeneity are presented. To date, >1000 mutations in the heme biosynthetic genes causing their respective porphyrias have been reported, including low expression alleles and genotype/phenotype correlations that predict severity for certain porphyrias. The tissue-specific regulation of heme biosynthesis and the unique genetic mechanisms for each porphyria are highlighted.
Collapse
Affiliation(s)
- Makiko Yasuda
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Brenden Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| |
Collapse
|
4
|
Moghe A, Ramanujam V, Phillips J, Desnick R, Anderson K. Harderoporphyria: Case of lifelong photosensitivity associated with compound heterozygous coproporphyrinogen oxidase (CPOX) mutations. Mol Genet Metab Rep 2019; 19:100457. [PMID: 30828546 PMCID: PMC6383327 DOI: 10.1016/j.ymgmr.2019.100457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/26/2019] [Indexed: 11/20/2022] Open
Abstract
A 78-year-old man with a history of neonatal anemia and jaundice and life-long photosensitivity was found to have harderoporphyria, as evidenced by increased porphyrins in urine, plasma, erythrocytes and feces including large amounts of harderoporphyrin in feces and erythrocytes. Two previously undescribed coproporphyrinogen oxidase (CPOX) mutations were identified, including a deletion of four amino acids in a region of the enzyme mutated in 7 of the 8 previously reported cases. This case increases the molecular heterogeneity of this rare porphyria, and illustrates that it should be considered as a cause of chronic photosensitivity and porphyrin elevation at any age.
Collapse
Affiliation(s)
- A. Moghe
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA
| | - V.M.S. Ramanujam
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA
| | - J.D. Phillips
- Department of Medicine, University of Utah, Salt Lake City, UT, USA
| | - R.J. Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mt. Sinai, New York, NY, USA
| | - K.E. Anderson
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA
- Corresponding author at: Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX 77555-1109, USA.
| |
Collapse
|
5
|
Borrero Corte MJ, Jara Rubio F, Morán Jiménez MJ, Díaz Díaz S, Castelbón Fernandez FJ, García Pastor I, Enríquez de Salamanca R, Méndez M. Molecular analysis of 19 Spanish patients with mixed porphyrias. Eur J Med Genet 2018; 62:103589. [PMID: 30476629 DOI: 10.1016/j.ejmg.2018.11.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/12/2018] [Accepted: 11/22/2018] [Indexed: 01/07/2023]
Abstract
Porphyrias are rare diseases caused by alterations in the heme biosynthetic pathway. Depending on the afected enzyme, porphyrin precursors or porphyrins are overproduced, causing acute neurovisceral attacks or dermal photosensitivity, respectively. Hereditary Coproporphyria (HCP) and Variegate Porphyria (VP) are mixed porphyrias since they can present acute and/or cutaneous symptoms. These diseases are caused by a deficiency of coproporphyrinogen oxidase (CPOX) in HCP, and protoporphyrinogen oxidase (PPOX) in VP. Herein, we studied nineteen unrelated Spanish patients with mixed porphyrias. The diagnosis of either, HCP or VP was made on the basis of clinical symptoms, biochemical findings and the identification of the mutation responsible in the CPOX or PPOX genes. Two patients presented both acute and cutaneous symptoms. In most patients, the biochemical data allowed the diagnosis. Among eleven patients with HCP, ten CPOX mutations were identified, including six novel ones: two frameshift (c.32delG and c.1102delC), two nonsense (p.Cys239Ter and p.Tyr365Ter), one missense (p.Trp275Arg) and one amino acid deletion (p.Gly336del). Moreover, seven previously described PPOX mutations were identified in eight patients with VP. The impacts of CPOX mutations p.Trp275Arg and p.Gly336del, were evaluated using prediction softwares and their functional consequences were studied in a prokaryotic expression system. Both alterations were predicted as deleterious by in silico analysis. Aditionally, when these alleles were expressed in E. coli, only p.Trp275Arg retained some residual activity. These results emphasize the usefulness of integrated the biochemical tests and molecular studies in the diagnosis. Furthermore, they extend knowledge on the molecular heterogeneity of mixed porphyrias in Spain.
Collapse
Affiliation(s)
| | | | | | - Silvia Díaz Díaz
- Servicio de Análisis Clínicos, Hospital 12 de Octubre, Madrid, Spain
| | | | | | | | - Manuel Méndez
- Instituto de Investigación Hospital 12 de Octubre, Madrid, Spain.
| |
Collapse
|
6
|
|
7
|
Conway AJ, Brown FC, Fullinfaw RO, Kile BT, Jane SM, Curtis DJ. A mouse model of hereditary coproporphyria identified in an ENU mutagenesis screen. Dis Model Mech 2017; 10:1005-1013. [PMID: 28600349 PMCID: PMC5560062 DOI: 10.1242/dmm.029116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 06/02/2017] [Indexed: 12/14/2022] Open
Abstract
A genome-wide ethyl-N-nitrosourea (ENU) mutagenesis screen in mice was performed to identify novel regulators of erythropoiesis. Here, we describe a mouse line, RBC16, which harbours a dominantly inherited mutation in the Cpox gene, responsible for production of the haem biosynthesis enzyme, coproporphyrinogen III oxidase (CPOX). A premature stop codon in place of a tryptophan at amino acid 373 results in reduced mRNA expression and diminished protein levels, yielding a microcytic red blood cell phenotype in heterozygous mice. Urinary and faecal porphyrins in female RBC16 heterozygotes were significantly elevated compared with that of wild-type littermates, particularly coproporphyrinogen III, whereas males were biochemically normal. Attempts to induce acute porphyric crises were made using fasting and phenobarbital treatment on females. While fasting had no biochemical effect on RBC16 mice, phenobarbital caused significant elevation of faecal coproporphyrinogen III in heterozygous mice. This is the first known investigation of a mutagenesis mouse model with genetic and biochemical parallels to hereditary coproporphyria.
Collapse
Affiliation(s)
- Ashlee J Conway
- Australian Centre for Blood Diseases, Monash University and Clinical Haematology, Alfred Health, Melbourne 3004, Australia
| | - Fiona C Brown
- Australian Centre for Blood Diseases, Monash University and Clinical Haematology, Alfred Health, Melbourne 3004, Australia
| | - Robert O Fullinfaw
- Porphyria Reference Laboratory, Biochemistry Department, Royal Melbourne Hospital, Parkville 3050, Australia
| | - Benjamin T Kile
- ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia
| | - Stephen M Jane
- Australian Centre for Blood Diseases, Monash University and Clinical Haematology, Alfred Health, Melbourne 3004, Australia.,Central Clinical School, Monash University, Melbourne 3004, Australia
| | - David J Curtis
- Australian Centre for Blood Diseases, Monash University and Clinical Haematology, Alfred Health, Melbourne 3004, Australia
| |
Collapse
|
8
|
Woolf J, Marsden JT, Degg T, Whatley S, Reed P, Brazil N, Stewart MF, Badminton M. Best practice guidelines on first-line laboratory testing for porphyria. Ann Clin Biochem 2017; 54:188-198. [DOI: 10.1177/0004563216667965] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The porphyrias are disorders of haem biosynthesis which present with acute neurovisceral attacks or disorders of sun-exposed skin. Acute attacks occur mainly in adults and comprise severe abdominal pain, nausea, vomiting, autonomic disturbance, central nervous system involvement and peripheral motor neuropathy. Cutaneous porphyrias can be acute or chronic presenting at various ages. Timely diagnosis depends on clinical suspicion leading to referral of appropriate samples for screening by reliable biochemical methods. All samples should be protected from light. Investigation for an acute attack: • Porphobilinogen (PBG) quantitation in a random urine sample collected during symptoms. Urine concentration must be assessed by measuring creatinine, and a repeat requested if urine creatinine <2 mmol/L. • Urgent porphobilinogen testing should be available within 24 h of sample receipt at the local laboratory. Urine porphyrin excretion (TUP) should subsequently be measured on this urine. • Urine porphobilinogen should be measured using a validated quantitative ion-exchange resin-based method or LC-MS. • Increased urine porphobilinogen excretion requires confirmatory testing and clinical advice from the National Acute Porphyria Service. • Identification of individual acute porphyrias requires analysis of urine, plasma and faecal porphyrins. Investigation for cutaneous porphyria: • An EDTA blood sample for plasma porphyrin fluorescence emission spectroscopy and random urine sample for TUP. • Whole blood for porphyrin analysis is essential to identify protoporphyria. • Faeces need only be collected, if first-line tests are positive or if clinical symptoms persist. Investigation for latent porphyria or family history: • Contact a specialist porphyria laboratory for advice. Clinical, family details are usually required.
Collapse
Affiliation(s)
- Jacqueline Woolf
- Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, UK
| | - Joanne T Marsden
- Reference Biochemistry Laboratories, Viapath, King’s College Hospital, London, UK
| | - Timothy Degg
- Department of Clinical Biochemistry, Leeds Teaching Hospitals Trust, Leeds, UK
| | - Sharon Whatley
- Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, UK
| | - Paul Reed
- Department of Clinical Biochemistry, Salford Royal NHS Foundation Trust, Salford, UK
| | - Nadia Brazil
- Department of Biochemistry, St James Hospital, Dublin, Ireland
| | - M Felicity Stewart
- Department of Clinical Biochemistry, Salford Royal NHS Foundation Trust, Salford, UK
| | - Michael Badminton
- Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, UK
| |
Collapse
|
9
|
Abstract
Acute porphyrias are rare inherited disorders due to deficiencies of haem synthesis enzymes. To date, all UK cases have been one of the three autosomal dominant forms, although penetrance is low and most gene carriers remain asymptomatic. Clinical presentation is typically with acute neurovisceral attacks characterised by severe abdominal pain, vomiting, tachycardia and hypertension. Severe attacks may be complicated by hyponatraemia, peripheral neuropathy sometimes causing paralysis, seizures and psychiatric features. Attacks are triggered by prescribed drugs, alcohol, hormonal changes, fasting or stress. The diagnosis is made by finding increased porphobilinogen excretion in a light-protected random urine sample. Management includes administration of intravenous human haemin and supportive treatment with non-porphyrinogenic drugs. A few patients develop recurrent attacks, a chronic illness requiring specialist management. Late complications include chronic pain, hepatocellular carcinoma, chronic renal failure and hypertension. In the UK, the National Acute Porphyria Service provides clinical advice and supplies haemin when indicated.
Collapse
Affiliation(s)
- Penelope E Stein
- Department of Haematological Medicine, King's College Hospital, London, UK
| | - Michael N Badminton
- Department of Medical Biochemistry and Immunology, University Hospital of Wales, Cardiff, UK
| | - David C Rees
- Department of Haematological Medicine, King's College Hospital, London, UK
| |
Collapse
|
10
|
Fukuda Y, Cheong PL, Lynch J, Brighton C, Frase S, Kargas V, Rampersaud E, Wang Y, Sankaran VG, Yu B, Ney PA, Weiss MJ, Vogel P, Bond PJ, Ford RC, Trent RJ, Schuetz JD. The severity of hereditary porphyria is modulated by the porphyrin exporter and Lan antigen ABCB6. Nat Commun 2016; 7:12353. [PMID: 27507172 PMCID: PMC4987512 DOI: 10.1038/ncomms12353] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 06/23/2016] [Indexed: 01/10/2023] Open
Abstract
Hereditary porphyrias are caused by mutations in genes that encode haem biosynthetic enzymes with resultant buildup of cytotoxic metabolic porphyrin intermediates. A long-standing open question is why the same causal porphyria mutations exhibit widely variable penetrance and expressivity in different individuals. Here we show that severely affected porphyria patients harbour variant alleles in the ABCB6 gene, also known as Lan, which encodes an ATP-binding cassette (ABC) transporter. Plasma membrane ABCB6 exports a variety of disease-related porphyrins. Functional studies show that most of these ABCB6 variants are expressed poorly and/or have impaired function. Accordingly, homozygous disruption of the Abcb6 gene in mice exacerbates porphyria phenotypes in the Fechm1Pas mouse model, as evidenced by increased porphyrin accumulation, and marked liver injury. Collectively, these studies support ABCB6 role as a genetic modifier of porphyria and suggest that porphyrin-inducing drugs may produce excessive toxicities in individuals with the rare Lan(−) blood type. Accumulation of intermediates of haem biosynthesis, porphyrins, is harmful and usually inherited, but it is unclear how the same mutation may make some individuals more ill than others. Here, the authors show that a porphyrin transporter ABCB6 is a modulator of porphyria, and that patients with functionally defective ABCB6 show more severe symptoms.
Collapse
Affiliation(s)
- Yu Fukuda
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Pak Leng Cheong
- Department of Medical Genomics, Royal Prince Alfred Hospital, Sydney, New South Wales 2050, Australia.,Sydney Medical School, University of Sydney, Sydney, New South Wales 2006, Australia
| | - John Lynch
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Cheryl Brighton
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Sharon Frase
- Department of Tissue Cell Biology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Vasileios Kargas
- Department of Structural Biology, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Evadnie Rampersaud
- Department of Computational Biology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.,Department of Hematology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Yao Wang
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Vijay G Sankaran
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Bing Yu
- Department of Medical Genomics, Royal Prince Alfred Hospital, Sydney, New South Wales 2050, Australia.,Sydney Medical School, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Paul A Ney
- New York Blood Center, New York, New York 10065, USA
| | - Mitchell J Weiss
- Department of Hematology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Peter Vogel
- Department of Pathology, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Peter J Bond
- Bioinformatics Institute, 30 Biopolis Street, Singapore 138671, Singapore.,Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Robert C Ford
- Department of Structural Biology, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Ronald J Trent
- Department of Medical Genomics, Royal Prince Alfred Hospital, Sydney, New South Wales 2050, Australia.,Sydney Medical School, University of Sydney, Sydney, New South Wales 2006, Australia
| | - John D Schuetz
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| |
Collapse
|
11
|
Horner ME, Alikhan A, Tintle S, Tortorelli S, Davis DMR, Hand JL. Cutaneous porphyrias part I: epidemiology, pathogenesis, presentation, diagnosis, and histopathology. Int J Dermatol 2014; 52:1464-80. [PMID: 24261722 DOI: 10.1111/ijd.12305] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The porphyrias are a group of disorders characterized by defects in the heme biosynthesis pathway. Many present with skin findings including photosensitivity, bullae, hypertrichosis, and scarring. Systemic symptoms may include abdominal pain, neuropsychiatric changes, anemia, and liver disease. With advances in DNA analysis, researchers are discovering the underlying genetic causes of the porphyrias, enabling family members to be tested for genetic mutations. Here we present a comprehensive review of porphyria focusing on those with cutaneous manifestations. In Part I, we have included the epidemiology, pathogenesis, presentation, diagnosis, and histopathology. Treatment and management options will be discussed in Part II.
Collapse
Affiliation(s)
- Mary E Horner
- Department of Dermatology, Baylor University Medical Center, Dallas, TX, USA
| | | | | | | | | | | |
Collapse
|
12
|
Kim DHT, Hino R, Adachi Y, Kobori A, Taketani S. The enzyme engineering of mutant homodimer and heterodimer of coproporphyinogen oxidase contributes to new insight into hereditary coproporphyria and harderoporphyria. J Biochem 2013; 154:551-9. [DOI: 10.1093/jb/mvt086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
13
|
Tintle S, Alikhan A, Horner ME, Hand JL, Davis DMR. Cutaneous porphyrias part II: treatment strategies. Int J Dermatol 2013; 53:3-24. [PMID: 24134210 DOI: 10.1111/ijd.12016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The porphyrias are diverse in pathophysiology, clinical presentation, severity, and prognosis, presenting a diagnostic and therapeutic challenge. Although not easily curable, the dermatological manifestations of these diseases, photosensitivity and associated cutaneous pathology, can be effectively prevented and managed. Sun avoidance is essential, and patient education regarding the irreversibility of photocutaneous damage is a necessary corollary. Beyond preventative measures, the care of fragile, vulnerable skin, and pain management, each of the porphyrias has a limited number of unique additional therapeutic options. Many of the treatments have been published only in small case series or anecdotal reports and do not have well-understood nor proven mechanisms of action. This article presents a comprehensive review of available therapeutic options and long-term management recommendations for the cutaneous porphyrias.
Collapse
Affiliation(s)
- Suzanne Tintle
- Department of Dermatology, Tufts Medical Center, Boston, MA, USA
| | | | | | | | | |
Collapse
|
14
|
Mori M, Gotoh S, Taketani S, Hiai H, Higuchi K. Hereditary cataract of the Nakano mouse: Involvement of a hypomorphic mutation in the coproporphyrinogen oxidase gene. Exp Eye Res 2013; 112:45-50. [PMID: 23631845 DOI: 10.1016/j.exer.2013.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/05/2013] [Accepted: 04/09/2013] [Indexed: 11/17/2022]
Abstract
The Nakano cataract (NCT) is a recessive disorder in the mouse linked to the nct locus on chromosome 16. In this study, we positionally cloned the critical gene in the nct locus. Herein, we report that cataracts in the BALB/c-nct/nct mouse are caused by a hypomorphic mutation in the coproporphyrin oxidase gene (Cpox), encoding the enzyme responsible for catalyzing oxidative decarboxylation of the heme precursor, coproporphyrinogen III, in the heme biosynthetic pathway. BALB/c-nct/nct mice are homozygous for a G to T nucleotide substitution in the Cpox gene, which results in a p.R380L amino acid substitution in the CPOX protein. The CPOX isoform with the p.R380L substitution retained only 15% of the activity of the wild type isoform. BALB/c-nct/nct mice had excessive accumulation of coproporphyrin III in the lens. The NCT phenotype was normalized by the introduction of a wild type Cpox transgene. The mechanisms by which impairment of CPOX leads to lens opacity in the NCT are elusive. However, our data illuminate a hitherto unanticipated involvement of the heme biosynthesis pathway in lens physiology.
Collapse
Affiliation(s)
- Masayuki Mori
- Department of Aging Biology, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
| | | | | | | | | |
Collapse
|
15
|
Rudd A, Grant J, Varigos G, Morgan V, Winship I. Co-existence of hereditary coproporphyria and porphyria cutanea tarda: The importance of genetic testing. Australas J Dermatol 2012; 54:e50-2. [DOI: 10.1111/j.1440-0960.2011.00875.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Aarsand AK, Villanger JH, Støle E, Deybach JC, Marsden J, To-Figueras J, Badminton M, Elder GH, Sandberg S. European Specialist Porphyria Laboratories: Diagnostic Strategies, Analytical Quality, Clinical Interpretation, and Reporting As Assessed by an External Quality Assurance Program. Clin Chem 2011; 57:1514-23. [DOI: 10.1373/clinchem.2011.170357] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND
The porphyrias are a group of rare metabolic disorders whose diagnosis depends on identification of specific patterns of porphyrin precursor and porphyrin accumulation in urine, blood, and feces. Diagnostic tests for porphyria are performed by specialized laboratories in many countries. Data regarding the analytical and diagnostic performance of these laboratories are scarce.
METHODS
We distributed 5 sets of multispecimen samples from different porphyria patients accompanied by clinical case histories to 18–21 European specialist porphyria laboratories/centers as part of a European Porphyria Network organized external analytical and postanalytical quality assessment (EQA) program. The laboratories stated which analyses they would normally have performed given the case histories and reported results of all porphyria-related analyses available, interpretative comments, and diagnoses.
RESULTS
Reported diagnostic strategies initially showed considerable diversity, but the number of laboratories applying adequate diagnostic strategies increased during the study period. We found an average interlaboratory CV of 50% (range 12%–152%) for analytes in absolute concentrations. Result normalization by forming ratios to the upper reference limits did not reduce this variation. Sixty-five percent of reported results were within biological variation–based analytical quality specifications. Clinical interpretation of the obtained analytical results was accurate, and most laboratories established the correct diagnosis in all distributions.
CONCLUSIONS
Based on a case-based EQA scheme, variations were apparent in analytical and diagnostic performance between European specialist porphyria laboratories. Our findings reinforce the use of EQA schemes as an essential tool to assess both analytical and diagnostic processes and thereby to improve patient care in rare diseases.
Collapse
Affiliation(s)
- Aasne K Aarsand
- Norwegian Porphyria Centre (NAPOS), Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
| | - Jørild H Villanger
- Norwegian Porphyria Centre (NAPOS), Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
| | - Egil Støle
- Norwegian Porphyria Centre (NAPOS), Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
| | - Jean-Charles Deybach
- Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, Colombes CEDEX and INSERM Unité 773, Centre de Recherche Biomedicale Bichat-Beaujon, Université Paris Diderot, Paris, France
| | - Joanne Marsden
- Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, Denmark Hill, London, UK
| | - Jordi To-Figueras
- Biochemistry and Molecular Genetics Unit, Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | - Mike Badminton
- Department of Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - George H Elder
- Department of Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - Sverre Sandberg
- Norwegian Porphyria Centre (NAPOS), Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
- Norwegian Quality Improvement of Primary Care Laboratories (NOKLUS), Section for General Practice, University of Bergen, Bergen, Norway
| |
Collapse
|
17
|
Barbaro M, Kotajärvi M, Harper P, Floderus Y. Identification of an AluY-mediated deletion of exon 5 in the CPOX gene by MLPA analysis in patients with hereditary coproporphyria. Clin Genet 2011; 81:249-56. [PMID: 21231929 DOI: 10.1111/j.1399-0004.2011.01628.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hereditary coproporphyria (HCP) is an autosomal dominantly inherited hepatic porphyria, caused by a mutation in the coproporphyrinogen oxidase (CPOX) gene. The genetic defect leads to a partial defect of CPOX, the sixth enzyme involved in haem biosynthesis. Affected individuals can develop acute life-threatening attacks of neurovisceral symptoms and/or more rarely cutaneous symptoms such as skin fragility and blistering. The identification of the genetic defect in HCP families is of crucial importance to detect the carrier status which allows counselling to prevent possible triggering factors, e.g. certain drugs, alcohol, or fasting. In a total of nine Swedish HCP families, routine gene sequence analysis had identified a causative mutation in only five. In the present study, using an in-house developed synthetic probe set for multiplex ligation-dependent probe amplification (MLPA) analysis, we detected a deletion of the fifth exon in the CPOX gene in the remaining four families. The deletion is 3381 bp in size and has originated by an Alu-mediated mechanism. This finding emphasizes the usefulness of MLPA analysis as a complement to gene sequencing for comprehensive genetic diagnostics in HCP patients.
Collapse
Affiliation(s)
- M Barbaro
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | | | | | | |
Collapse
|
18
|
Hasanoglu A, Balwani M, Kasapkara CS, Ezgü FS, Okur I, Tümer L, Cakmak A, Nazarenko I, Yu C, Clavero S, Bishop DF, Desnick RJ. Harderoporphyria due to homozygosity for coproporphyrinogen oxidase missense mutation H327R. J Inherit Metab Dis 2011; 34:225-31. [PMID: 21103937 PMCID: PMC3091031 DOI: 10.1007/s10545-010-9237-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/08/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
Abstract
Hereditary coproporphyria (HCP) is an autosomal dominant acute hepatic porphyria due to the half-normal activity of the heme biosynthetic enzyme, coproporphyrinogen oxidase (CPOX). The enzyme catalyzes the step-wise oxidative decarboxylation of the heme precursor, coproporphyrinogen III, to protoporphyrinogen IX via a tricarboxylic intermediate, harderoporphyrinogen. In autosomal dominant HCP, the deficient enzymatic activity results primarily in the accumulation of coproporphyrin III. To date, only a few homozygous HCP patients have been described, most having Harderoporphyria, a rare variant due to specific CPOX mutations that alter enzyme residues D400-K404, most patients described to date having at least one K404E allele. Here, we describe a Turkish male infant, the product of a consanguineous union, who presented with the Harderoporphyria phenotype including neonatal hyperbilirubinemia, hemolytic anemia, hepatosplenomegaly, and skin lesions when exposed to UV light. He was homoallelic for the CPOX missense mutation, c.980A>G (p.H327R), and had massively increased urinary uroporphyrins I and III (9,250 and 2,910 μM, respectively) and coproporphyrins I and III (895 and 19,400 μM, respectively). The patient expired at 5 months of age from an apparent acute neurologic porphyric attack. Structural studies predicted that p.H327R interacts with residue W399 in the CPOX active site, thereby accounting for the Harderoporphyria phenotype.
Collapse
Affiliation(s)
- Alev Hasanoglu
- Department of Pediatric Metabolism and Nutrition, Gazi University Hospital, Ankara, Turkey
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Cappellini MD, Brancaleoni V, Graziadei G, Tavazzi D, Di Pierro E. Porphyrias at a glance: diagnosis and treatment. Intern Emerg Med 2010; 5 Suppl 1:S73-80. [PMID: 20865478 DOI: 10.1007/s11739-010-0449-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Porphyrias are a group of eight rare inherited metabolic disorders of heme biosynthesis pathway. Porphyrias are still underdiagnosed, although examinations of urine and plasma are first-line tests for detecting excess of porphyrins or heme precursors in suspected patients. Diagnosis, particularly for the acute forms, is essential to avoid precipitating factors and the use of triggering drugs. Mutation screening of family members is recommended to identify presymptomatic carriers and to prevent acute attacks. The therapeutic approach should be appropriate regarding specific forms of porphyria and treatment should be started promptly.
Collapse
Affiliation(s)
- Maria Domenica Cappellini
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Università degli Studi di Milano, Via F. Sforza 35, 20122, Milan, Italy.
| | | | | | | | | |
Collapse
|
20
|
Siegesmund M, van Tuyll van Serooskerken AM, Poblete-Gutiérrez P, Frank J. The acute hepatic porphyrias: current status and future challenges. Best Pract Res Clin Gastroenterol 2010; 24:593-605. [PMID: 20955962 DOI: 10.1016/j.bpg.2010.08.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 08/26/2010] [Accepted: 08/28/2010] [Indexed: 01/31/2023]
Abstract
The porphyrias are predominantly inherited metabolic disorders, which result from a specific deficiency of one of the eight enzymes along the pathway of haem biosynthesis. Historically, they have been classified into hepatic and erythropoietic forms, based on the primary site of expression of the prevailing dysfunctional enzyme. From a clinical point of view, however, it is more convenient to subdivide them into acute and non-acute porphyrias, thereby primarily considering the potential occurrence of life-threatening acute neurovisceral attacks. Unrecognised or untreated, such an acute porphyric attack is associated with a significant mortality of up to 10%. The acute hepatic porphyrias comprise acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and δ-aminolevulinic acid dehydratase deficiency porphyria. Making a precise diagnosis may be difficult because the different types of porphyrias may show overlapping clinical and biochemical characteristics. To date, the therapeutic possibilities are limited and mainly symptomatic. In this overview we report on what is currently known about pathogenesis, clinic, diagnostics, and therapy of the acute hepatic porphyrias. We further point out actual and future challenges in the management of these diseases.
Collapse
Affiliation(s)
- Marko Siegesmund
- Department of Dermatology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | | | | | | |
Collapse
|
21
|
Abstract
Hereditary porphyrias are a group of eight metabolic disorders of the haem biosynthesis pathway that are characterised by acute neurovisceral symptoms, skin lesions, or both. Every porphyria is caused by abnormal function of a separate enzymatic step, resulting in a specific accumulation of haem precursors. Seven porphyrias are the result of a partial enzyme deficiency, and a gain of function mechanism has been characterised in a new porphyria. Acute porphyrias present with acute attacks, typically consisting of severe abdominal pain, nausea, constipation, confusion, and seizure, and can be life-threatening. Cutaneous porphyrias present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe cutaneous photosensitivity and chronic haemolysis or chronic neurological symptoms with or without photosensitivity. Porphyrias are still underdiagnosed, but when they are suspected, and dependent on clinical presentation, simple first-line tests can be used to establish the diagnosis in all symptomatic patients. Diagnosis is essential to enable specific treatments to be started as soon as possible. Screening of families to identify presymptomatic carriers is crucial to decrease risk of overt disease of acute porphyrias through counselling about avoidance of potential precipitants.
Collapse
Affiliation(s)
- Hervé Puy
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, Colombes, France
| | | | | |
Collapse
|
22
|
Whatley SD, Mason NG, Woolf JR, Newcombe RG, Elder GH, Badminton MN. Diagnostic strategies for autosomal dominant acute porphyrias: retrospective analysis of 467 unrelated patients referred for mutational analysis of the HMBS, CPOX, or PPOX gene. Clin Chem 2009; 55:1406-14. [PMID: 19460837 DOI: 10.1373/clinchem.2008.122564] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Clinically indistinguishable attacks of acute porphyria occur in acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), and variegate porphyria (VP). There are few evidence-based diagnostic strategies for these disorders. METHODS The diagnostic sensitivity of mutation detection was determined by sequencing and gene-dosage analysis to search for mutations in 467 sequentially referred, unrelated patients. The diagnostic accuracy of plasma fluorescence scanning, fecal porphyrin analysis, and porphobilinogen deaminase (PBGD) assay was assessed in mutation-positive patients (AIP, 260 patients; VP, 152 patients; HCP, 31 patients). RESULTS Sensitivities (95% CI) for mutation detection were as follows: AIP, 98.1% (95.6%-99.2%); HCP, 96.9% (84.3%-99.5%); VP, 100% (95.7%-100%). We identified 5 large deletions in the HMBS gene (hydroxymethylbilane synthase) and one in the CPOX gene (coproporphyrinogen oxidase). The plasma fluorescence scan was positive more often in VP (99% of patients) than in AIP (68%) or HCP (29%). The wavelength of the fluorescence emission peak and the fecal coproporphyrin isomer ratio had high diagnostic specificity and sensitivity for differentiating between AIP, HCP, and VP. DNA analysis followed by PBGD assay in mutation-negative patients had greater diagnostic accuracy for AIP than either test alone. CONCLUSIONS When PBG excretion is increased, 2 investigations (plasma fluorescence scanning, the coproporphyrin isomer ratio) are sufficient, with rare exceptions, to identify the type of acute porphyria. When the results of PBG, 5-aminolevulinate, and porphyrin analyses are within reference intervals and clinical suspicion that a past illness was caused by an acute porphyria remains high, mutation analysis of the HMBS gene followed by PBGD assay is an effective strategy for diagnosis or exclusion of AIP.
Collapse
Affiliation(s)
- Sharon D Whatley
- Department of Medical Biochemistry and Immunology, University Hospital of Wales and School of Medicine, Cardiff University, Cardiff, UK.
| | | | | | | | | | | |
Collapse
|
23
|
Erupciones inflamatorias y purpúricas. DERMATOLOGÍA NEONATAL 2009. [PMCID: PMC7161408 DOI: 10.1016/b978-84-8086-390-2.50019-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
|
24
|
Baselga E, Torrelo A. Inflammatory and Purpuric Eruptions. NEONATAL DERMATOLOGY 2008. [PMCID: PMC7315339 DOI: 10.1016/b978-1-4160-3432-2.50022-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
25
|
Stephenson JR, Stacey JA, Morgenthaler JB, Friesen JA, Lash TD, Jones MA. Role of aspartate 400, arginine 262, and arginine 401 in the catalytic mechanism of human coproporphyrinogen oxidase. Protein Sci 2007; 16:401-10. [PMID: 17242372 PMCID: PMC2203308 DOI: 10.1110/ps.062636907] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Coproporphyrinogen oxidase (CPO) is the sixth enzyme in the heme biosynthetic pathway, catalyzing two sequential oxidative decarboxylations of propionate moieties on coproporphyrinogen-III forming protoporphyrinogen-IX through a monovinyl intermediate, harderoporphyrinogen. Site-directed mutagenesis studies were carried out on three invariant amino acids, aspartate 400, arginine 262, and arginine 401, to determine residue contribution to substrate binding and/or catalysis by human recombinant CPO. Kinetic analyses were performed on mutant enzymes incubated with three substrates, coproporphyrinogen-III, harderoporphyrinogen, or mesoporphyrinogen-VI, in order to determine catalytic ability to perform the first and/or second oxidative decarboxylation. When Asp400 was mutated to alanine no divinyl product was detected, but the production of a small amount of monovinyl product suggested the K(m) value for coproporphyrinogen-III did not change significantly compared to the wild-type enzyme. Upon mutation of Arg262 to alanine, CPO was again a poor catalyst for the production of a divinyl product, with a catalytic efficiency <0.01% compared to wild-type, including a 15-fold higher K(m) for coproporphyrinogen-III. The efficiency of divinyl product formation for mutant enzyme Arg401Ala was approximately 3% compared to wild-type CPO, with a threefold increase in the K(m) value for coproporphyrinogen-III. These data suggest Asp400, Arg262, and Arg401 are active site amino acids critical for substrate binding and/or catalysis. Possible roles for arginine 262 and 401 include coordination of carboxylate groups of coproporphyrinogen-III, while aspartate 400 may initiate deprotonation of substrate, resulting in an oxidative decarboxylation.
Collapse
Affiliation(s)
- Jason R Stephenson
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA
| | | | | | | | | | | |
Collapse
|
26
|
Hanaoka R, Katayama S, Dawid IB, Kawahara A. Characterization of the heme synthesis enzyme coproporphyrinogen oxidase (CPO) in zebrafish erythrogenesis. Genes Cells 2006; 11:293-303. [PMID: 16483317 DOI: 10.1111/j.1365-2443.2006.00939.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hemoglobin consists of heme and globin proteins and is essential for oxygen transport in all vertebrates. Although biochemical features of heme synthesis enzymes have been well characterized, the function of these enzymes in early embryogenesis is not fully understood. We found that the sixth heme synthesis enzyme, coproporphyrinogen oxidase (CPO), is predominantly expressed in the intermediate cell mass (ICM) that is a major site of zebrafish primitive hematopoiesis. Knockdown of zebrafish CPO using anti-sense morpholinos (CPO-MO) leads to a significant suppression of hemoglobin production without apparent reduction of blood cells. Injection of human CPO RNA, but not a mutant CPO RNA that is similar to a mutant responsible for a hereditary coproporphyria (HCP), restores hemoglobin production in the CPO-MO-injected embryos. Furthermore, expression of CPO in the ICM is severely suppressed in both vlad tepes/gata1 mutants and in biklf-MO-injected embryos. In contrast, over-expression of biklf and gata1 significantly induces ectopic CPO expression. The function of CPO in heme biosynthesis is apparently conserved between zebrafish and human, suggesting that CPO-MO-injected zebrafish embryos might be a useful in vivo assay system to measure the biological activity of human CPO mutations.
Collapse
Affiliation(s)
- Ryuki Hanaoka
- Laboratory of Developmental Molecular Genetics, Horizontal Medical Research Organization, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-Ku, Kyoto, 606-8501, Japan
| | | | | | | |
Collapse
|
27
|
Lee DS, Flachsová E, Bodnárová M, Demeler B, Martásek P, Raman CS. Structural basis of hereditary coproporphyria. Proc Natl Acad Sci U S A 2005; 102:14232-7. [PMID: 16176984 PMCID: PMC1224704 DOI: 10.1073/pnas.0506557102] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Indexed: 11/18/2022] Open
Abstract
Hereditary coproporphyria is an autosomal dominant disorder resulting from the half-normal activity of coproporphyrinogen oxidase (CPO), a mitochondrial enzyme catalyzing the antepenultimate step in heme biosynthesis. The mechanism by which CPO catalyzes oxidative decarboxylation, in an extraordinary metal- and cofactor-independent manner, is poorly understood. Here, we report the crystal structure of human CPO at 1.58-A resolution. The structure reveals a previously uncharacterized tertiary topology comprising an unusually flat seven-stranded beta-sheet sandwiched by alpha-helices. In the biologically active dimer (K(D) = 5 x 10(-7) M), one monomer rotates relative to the second by approximately 40 degrees to create an intersubunit interface in close proximity to two independent enzymatic sites. The unexpected finding of citrate at the active site allows us to assign Ser-244, His-258, Asn-260, Arg-262, Asp-282, and Arg-332 as residues mediating substrate recognition and decarboxylation. We favor a mechanism in which oxygen serves as the immediate electron acceptor, and a substrate radical or a carbanion with substantial radical character participates in catalysis. Although several mutations in the CPO gene have been described, the molecular basis for how these alterations diminish enzyme activity is unknown. We show that deletion of residues (392-418) encoded by exon six disrupts dimerization. Conversely, harderoporphyria-causing K404E mutation precludes a type I beta-turn from retaining the substrate for the second decarboxylation cycle. Together, these findings resolve several questions regarding CPO catalysis and provide insights into hereditary coproporphyria.
Collapse
Affiliation(s)
- Dong-Sun Lee
- Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
28
|
Schmitt C, Gouya L, Malonova E, Lamoril J, Camadro JM, Flamme M, Rose C, Lyoumi S, Da Silva V, Boileau C, Grandchamp B, Beaumont C, Deybach JC, Puy H. Mutations in human CPO gene predict clinical expression of either hepatic hereditary coproporphyria or erythropoietic harderoporphyria. Hum Mol Genet 2005; 14:3089-98. [PMID: 16159891 DOI: 10.1093/hmg/ddi342] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hereditary coproporphyria (HCP), an autosomal dominant acute hepatic porphyria, results from mutations in the gene that encodes coproporphyrinogen III oxidase (CPO). HCP (heterozygous or rarely homozygous) patients present with an acute neurovisceral crisis, sometimes associated with skin lesions. Four patients (two families) have been reported with a clinically distinct variant form of HCP. In such patients, the presence of a specific mutation (K404E) on both alleles or associated with a null allele, produces a unifying syndrome in which hematological disorders predominate: 'harderoporphyria'. Here, we report the fifth case (from a third family) with harderoporphyria. In addition, we show that harderoporphyric patients exhibit iron overload secondary to dyserythropoiesis. To investigate the molecular basis of this peculiar phenotype, we first studied the secondary structure of the human CPO by a predictive method, the hydrophobic cluster analysis (HCA) which allowed us to focus on a region of the enzyme. We then expressed mutant enzymes for each amino acid of the region of interest, as well as all missense mutations reported so far in HCP patients and evaluated the amount of harderoporphyrin in each mutant. Our results strongly suggest that only a few missense mutations, restricted to five amino acids encoded by exon 6, may accumulate significant amounts of harderoporphyrin: D400-K404. Moreover, all other type of mutations or missense mutations mapped elsewhere throughout the CPO gene, lead to coproporphyrin accumulation and subsequently typical HCP. Our findings, reinforced by recent crystallographic results of yeast CPO, shed new light on the genetic predisposition to HCP. It represents a first monogenic metabolic disorder where clinical expression of overt disease is dependent upon the location and type of mutation, resulting either in acute hepatic or in erythropoietic porphyria.
Collapse
Affiliation(s)
- Caroline Schmitt
- INSERM U656 and Centre Français de Porphyries, Université Paris VII, Hôpital Louis Mourier, Colombes, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
To-Figueras J, Badenas C, Enríquez MT, Segura S, Alvarez C, Milà M, Lecha M, Herrero C. Biochemical and genetic characterization of four cases of hereditary coproporphyria in Spain. Mol Genet Metab 2005; 85:160-3. [PMID: 15896662 DOI: 10.1016/j.ymgme.2004.12.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Accepted: 12/23/2004] [Indexed: 01/02/2023]
Abstract
We report a biochemical and genetic characterization of four cases of hereditary coproporphyria (HCP) in Spain. All patients showed a typical HCP porphyrin excretion pattern with a high concentration of coproporphyrins in feces and inverted I:III isomer ratio. The porphyrin precursors in urine were found elevated in two patients who showed acute symptoms. The analysis of the CPO gene showed that three cases harboured novel mutations: V135A (404T>C; exon 1); L214R (641T>G; exon 2); and P249R (746C>G; exon 3) and in the fourth, a previously described R426X mutation in exon 6.
Collapse
Affiliation(s)
- Jordi To-Figueras
- Porphyria Unit, Centre Diagnòstic Biomèdic, Hospital Clínic, IDIBAPS, University of Barcelona, Villarroel 170, 08036 Barcelona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Allen KR, Whatley SD, Degg TJ, Barth JH. Hereditary coproporphyria: comparison of molecular and biochemical investigations in a large family. J Inherit Metab Dis 2005; 28:779-85. [PMID: 16151909 DOI: 10.1007/s10545-005-0092-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2005] [Accepted: 04/21/2005] [Indexed: 11/27/2022]
Abstract
Hereditary coproporphyria (HCP) is the least common of the three autosomal dominant acute porphyrias. To compare the sensitivity of metabolite measurements for the identification of asymptomatic HCP, we carried out a molecular and biochemical investigation of a large family in which HCP is caused by a previously unreported frameshift mutation (c.119delA). Thirteen of 19 asymptomatic family members, aged 10-72 years, were shown by mutational analysis to have HCP. The faecal coproporphyrin isomer III:I ratio was increased in all of these 13 family members; faecal total porphyrin concentration and urinary porphyrin excretion were increased in 11 and 8 of them, respectively. Plasma porphyrin concentrations were marginally increased in three individuals and plasma fluorescence emission scanning showed a porphyrin peak at 618 nm in two of these. Our results add to the evidence that an increased faecal porphyrin coproporphyrin III:I ratio is a highly sensitive test for the detection of clinically latent HCP in individuals over the age of 10 years; its sensitivity below this age remains uncertain. They also show that plasma fluorescence emission scanning is not useful for the investigation of families with HCP.
Collapse
Affiliation(s)
- K R Allen
- Department of Clinical Biochemistry, Leeds Teaching Hospitals, Leeds, UK.
| | | | | | | |
Collapse
|
31
|
Phillips JD, Whitby FG, Warby CA, Labbe P, Yang C, Pflugrath JW, Ferrara JD, Robinson H, Kushner JP, Hill CP. Crystal structure of the oxygen-dependant coproporphyrinogen oxidase (Hem13p) of Saccharomyces cerevisiae. J Biol Chem 2004; 279:38960-8. [PMID: 15194705 DOI: 10.1074/jbc.m406050200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Coproporphyrinogen oxidase (CPO) is an essential enzyme that catalyzes the sixth step of the heme biosynthetic pathway. Unusually for heme biosynthetic enzymes, CPO exists in two evolutionarily and mechanistically distinct families, with eukaryotes and some prokaryotes employing members of the highly conserved oxygen-dependent CPO family. Here, we report the crystal structure of the oxygen-dependent CPO from Saccharomyces cerevisiae (Hem13p), which was determined by optimized sulfur anomalous scattering and refined to a resolution of 2.0 A. The protein adopts a novel structure that is quite different from predicted models and features a central flat seven-stranded anti-parallel sheet that is flanked by helices. The dimeric assembly, which is seen in different crystal forms, is formed by packing of helices and a short isolated strand that forms a beta-ladder with its counterpart in the partner subunit. The deep active-site cleft is lined by conserved residues and has been captured in open and closed conformations in two different crystal forms. A substratesized cavity is completely buried in the closed conformation by the approximately 8-A movement of a helix that forms a lid over the active site. The structure therefore suggests residues that likely play critical roles in catalysis and explains the deleterious effect of many of the mutations associated with the disease hereditary coproporphyria.
Collapse
Affiliation(s)
- John D Phillips
- Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
|
33
|
Danton M, Lim CK. Identification of monovinyl tripropionic acid porphyrins and metabolites from faeces of patients with hereditary coproporphyria by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2004; 18:2309-2316. [PMID: 15384152 DOI: 10.1002/rcm.1628] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Harderoporphyrin (2-vinyl-4,6,7-tripropionic acid porphyrin) and its metabolites in faeces of patients with hereditary coproporphyria (HCP) have been separated and characterized by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC/ESI-Q-TOFMS/MS). The metabolites identified were 2-ethyl-4,6,7-tripropionic acid porphyrin, 2-hydro-4,6,7-tripropionic acid porphyrin, 2-methoxyethyl-4,6,7-tripropionic acid porphyrin and 2-acetyl-4,6,7-tripropionic acid porphyrin. Isomers of harderoporphyrin derived from isomerization of harderoporphyrinogen were also detected.
Collapse
Affiliation(s)
- Malcolm Danton
- MRC Bioanalytical Science Group, School of Biological & Chemical Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | | |
Collapse
|
34
|
Macieira S, Martins BM, Huber R. Oxygen-dependent coproporphyrinogen-III oxidase from Escherichia coli: one-step purification and biochemical characterisation. FEMS Microbiol Lett 2003; 226:31-7. [PMID: 13129604 DOI: 10.1016/s0378-1097(03)00531-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Coproporphyrinogen-III oxidase (CPO) catalyses the conversion of coproporphyrinogen-III to protoporphyrinogen-IX in the haem biosynthetic pathway, and its deficient activity is associated with human hereditary coproporphyria. The 47% sequence identity between the oxygen-dependent CPO from Escherichia coli and its human counterpart makes the bacterial enzyme a good model system for structural studies of this disease. Therefore, we overexpressed and purified to homogeneity the oxygen-dependent CPO from E. coli and its selenomethionine derivative fused with a His(6)-tag. Both preparations showed a specific activity of 37500 U mg(-1), had a subunit molecular mass of 35 kDa and behaved as a compact shaped dimer. First crystallisation trials produced plate-shaped diffracting crystals.
Collapse
Affiliation(s)
- Sofia Macieira
- Max-Planck-Institut für Biochemie, Abt. Strukturforschung, Am Klopferspitz, 18-a, 82152, Martinsried, Germany.
| | | | | |
Collapse
|
35
|
Abstract
The human hereditary hepatic porphyrias are diseases due to marked deficiencies of enzymes in the heme biosynthetic pathway. Porphyrias can be classified as either hepatic or erythroid, depending on the major production site of porphyrins or their precursors. The pathogenesis of inherited hepatic porphyrias has now been defined at the molecular level. Some gene carriers are vulnerable to a range of exogenous and endogenous factors, which may trigger neuropsychiatric and/or cutaneous symptoms. Early diagnosis is of prime importance since it makes way for counselling. In this article we present an overview of recent advances on hepatic porphyrias: 5-aminolevulinic acid dehydratase deficiency porphyria, acute intermittent porphyria (AIP), porphyria cutanea tarda (PCT), hereditary coproporphyria (HC), and variegate porphyria (VP).
Collapse
Affiliation(s)
- Yves Nordmann
- INSERM U409, Faculté de Médecine Xavier Bichat, Université Paris VII, 16, rue Henri Huchard, BP 416-75018, Paris Cedex 18, France.
| | | |
Collapse
|