1
|
Mohamed S, Ibrahim F, Alasafar MN, Alshurafa A, Akiki S, Soliman D, Kohla S, Amer A, Qasim H, Cherif H. Recurrent sideroblastic anemia during pregnancy. Clin Case Rep 2023; 11:e6814. [PMID: 36644616 PMCID: PMC9834147 DOI: 10.1002/ccr3.6814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 11/01/2022] [Accepted: 12/14/2022] [Indexed: 01/15/2023] Open
Abstract
Sideroblastic anemia is a heterogeneous group of disorders typified by the presence of ring sideroblasts in the bone marrow and has congenital and acquired types. Sideroblastic anemia is a rare event in pregnancy. We report a case of a 32-year-old female patient, gravida 4 para 3, 27th weeks pregnant, who presented to the emergency department complaining of palpitation and generalized weakness for 2 weeks. She was found to have severe normochromic normocytic anemia, with hemoglobin of 4.2 g/dl, and low reticulocytes count of 13 × 103/μl. She gave a history of recurrent anemia, which had only occurred during pregnancy. Her bone marrow aspirate showed many ring sideroblasts concluding the diagnosis of sideroblastic anemia (SA). Further investigation revealed a significantly low pyridoxine level (vitamin B6) of (8 nmol/L). The Hb level improved with vitamin B6 replacement, without any transfusion support.
Collapse
Affiliation(s)
- Shehab Mohamed
- Department of HematologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Firyal Ibrahim
- Department of Laboratory Medicine and PathologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | | | - Awni Alshurafa
- Department of HematologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Susanna Akiki
- Department of Laboratory Medicine and PathologyHamad Medical CorporationDohaQatar,Weill Cornell Medicine‐QatarDohaQatar
| | - Dina Soliman
- Department of Laboratory Medicine and PathologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Samah Kohla
- Department of Laboratory Medicine and PathologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Aliaa Amer
- Department of Laboratory Medicine and PathologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Hana Qasim
- Department of HematologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| | - Honar Cherif
- Department of HematologyNational Center for Cancer Care and Research, Hamad Medical CorporationDohaQatar
| |
Collapse
|
2
|
Alam MM, Alathaibi A, Attar RA, Kashif M, Al-Ghamdi HS, Alharthi SA, Bokhary A, Althomali M. Pyridoxine Refractory Sideroblastic Anemia: Diagnosis and Misdiagnosis. CLINICAL PEDIATRIC HEMATOLOGY-ONCOLOGY 2022. [DOI: 10.15264/cpho.2022.29.2.65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
| | - Abdulrhman Alathaibi
- Department of Hematology/Oncology, Alhada Armed Forces Hospital, Taif, Saudi Arabia
| | - Ruwayd Adel Attar
- Department of Hematology/Oncology, Alhada Armed Forces Hospital, Taif, Saudi Arabia
| | - Muhammad Kashif
- Department of Laboratory, Alhada Armed Forces Hospital, Taif, Saudi Arabia
| | | | | | | | - Muteb Althomali
- Department of Hematology/Oncology, Alhada Armed Forces Hospital, Taif, Saudi Arabia
| |
Collapse
|
3
|
Essentiality of Trace Elements in Pregnancy, Fertility, and Gynecologic Cancers-A State-of-the-Art Review. Nutrients 2021; 14:nu14010185. [PMID: 35011060 PMCID: PMC8746721 DOI: 10.3390/nu14010185] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/23/2021] [Accepted: 12/28/2021] [Indexed: 12/18/2022] Open
Abstract
Gynecological neoplasms pose a serious threat to women's health. It is estimated that in 2020, there were nearly 1.3 million new cases worldwide, from which almost 50% ended in death. The most commonly diagnosed are cervical and endometrial cancers; when it comes to infertility, it affects ~48.5 million couples worldwide and the number is continually rising. Ageing of the population, environmental factors such as dietary habits, environmental pollutants and increasing prevalence of risk factors may affect the reproductive potential in women. Therefore, in order to identify potential risk factors for these issues, attention has been drawn to trace elements. Trace mineral imbalances can be caused by a variety of causes, starting with hereditary diseases, finishing with an incorrect diet or exposure to polluted air or water. In this review, we aimed to summarize the current knowledge regarding trace elements imbalances in the case of gynecologic cancers as well as female fertility and during pregnancy.
Collapse
|
4
|
Simpson SJ, Lim MY, George TI, Rets A. 36-year-old male with X-linked congenital sideroblastic anemia presenting as chronic microcytic anemia with iron overload. Int J Lab Hematol 2021; 44:69-71. [PMID: 34783180 DOI: 10.1111/ijlh.13761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/31/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Skyler J Simpson
- Department of Pathology, University of Utah Health, Salt Lake City, Utah, USA
| | - Ming Y Lim
- Division of Hematology and Hematologic Malignancy, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Tracy I George
- Department of Pathology, University of Utah Health, Salt Lake City, Utah, USA.,ARUP Laboratories Inc., Salt Lake City, Utah, USA
| | - Anton Rets
- Department of Pathology, University of Utah Health, Salt Lake City, Utah, USA.,ARUP Laboratories Inc., Salt Lake City, Utah, USA
| |
Collapse
|
5
|
Juchniewicz P, Piotrowska E, Kloska A, Podlacha M, Mantej J, Węgrzyn G, Tukaj S, Jakóbkiewicz-Banecka J. Dosage Compensation in Females with X-Linked Metabolic Disorders. Int J Mol Sci 2021; 22:ijms22094514. [PMID: 33925963 PMCID: PMC8123450 DOI: 10.3390/ijms22094514] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 01/19/2023] Open
Abstract
Through the use of new genomic and metabolomic technologies, our comprehension of the molecular and biochemical etiologies of genetic disorders is rapidly expanding, and so are insights into their varying phenotypes. Dosage compensation (lyonization) is an epigenetic mechanism that balances the expression of genes on heteromorphic sex chromosomes. Many studies in the literature have suggested a profound influence of this phenomenon on the manifestation of X-linked disorders in females. In this review, we summarize the clinical and genetic findings in female heterozygotic carriers of a pathogenic variant in one of ten selected X-linked genes whose defects result in metabolic disorders.
Collapse
Affiliation(s)
- Patrycja Juchniewicz
- Department of Medical Biology and Genetics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (P.J.); (A.K.); (J.J.-B.)
| | - Ewa Piotrowska
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (M.P.); (J.M.); (G.W.); (S.T.)
- Correspondence: ; Tel.: +48-58-523-6040
| | - Anna Kloska
- Department of Medical Biology and Genetics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (P.J.); (A.K.); (J.J.-B.)
| | - Magdalena Podlacha
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (M.P.); (J.M.); (G.W.); (S.T.)
| | - Jagoda Mantej
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (M.P.); (J.M.); (G.W.); (S.T.)
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (M.P.); (J.M.); (G.W.); (S.T.)
| | - Stefan Tukaj
- Department of Molecular Biology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (M.P.); (J.M.); (G.W.); (S.T.)
| | - Joanna Jakóbkiewicz-Banecka
- Department of Medical Biology and Genetics, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland; (P.J.); (A.K.); (J.J.-B.)
| |
Collapse
|
6
|
An WB, An WB, Liu C, Wan Y, Guo Y, Wang SC, Zhang YC, Zhu XF. [Clinical features and gene mutation spectrum in children with sideroblastic anemia]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2019; 21:1016-1021. [PMID: 31642437 PMCID: PMC7389731 DOI: 10.7499/j.issn.1008-8830.2019.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVE To study the clinical features and gene mutation spectrum of children with sideroblastic anemia (SA) and the clinical value of targeted next-generation sequencing in the molecular diagnosis of children with SA. METHODS Clinical data were collected from 36 children with SA. Targeted next-generation sequencing was used to detect mutations in SA-related pathogenic genes and genes associated with heme synthesis and mitochondrial iron metabolism. The association between genotype and clinical phenotype was analyzed. RESULTS Of the 36 patients, 32 had congenital sideroblastic anemia (CSA) and 4 had myelodysplastic syndrome with ring sideroblasts (MDS-RS). Mutations in CSA-related genes were detected in 19 children (19/36, 53%), among whom 9 (47%) had ALAS2 mutation, 4 (21%) had SLC25A38 mutation, and 6 (32%) had mitochondrial fragment deletion. No pathogenic gene mutation was detected in 4 children with MDS-RS. Among the 19 mutations, 89% (17/19) were known mutations and 11% (2/19) were novel mutations. The novel mutation of the ALAS2 gene c.1153A>T(p.I385F) was rated as "possibly pathogenic" and the novel mutation of the SLC25A38 gene c.175C>T(p.Q59X) was rated as "pathogenic". CONCLUSIONS ALAS2 and SLC25A38 gene mutations are commonly seen in children with CSA, but mitochondrial gene fragment deletion also accounts for a relatively high proportion. For children with hypoplastic anemia occurring in infancy, mitochondrial disease should be considered.
Collapse
Affiliation(s)
- Wen-Bin An
- Pediatric Blood Diseases Centre, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Ducamp S, Fleming MD. The molecular genetics of sideroblastic anemia. Blood 2019; 133:59-69. [PMID: 30401706 PMCID: PMC6318428 DOI: 10.1182/blood-2018-08-815951] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 09/21/2018] [Indexed: 01/19/2023] Open
Abstract
The sideroblastic anemias (SAs) are a group of inherited and acquired bone marrow disorders defined by pathological iron accumulation in the mitochondria of erythroid precursors. Like most hematological diseases, the molecular genetic basis of the SAs has ridden the wave of technology advancement. Within the last 30 years, with the advent of positional cloning, the human genome project, solid-state genotyping technologies, and next-generation sequencing have evolved to the point where more than two-thirds of congenital SA cases, and an even greater proportion of cases of acquired clonal disease, can be attributed to mutations in a specific gene or genes. This review focuses on an analysis of the genetics of these diseases and how understanding these defects may contribute to the design and implementation of rational therapies.
Collapse
Affiliation(s)
- Sarah Ducamp
- Department of Pathology, Boston Children's Hospital, Boston, MA
| | - Mark D Fleming
- Department of Pathology, Boston Children's Hospital, Boston, MA
| |
Collapse
|
8
|
Yu HJ, Lee YJ, Shim JW, Kim DS, Shim JY, Park MS, Woo HY, Park H, Jung HL, Kwon MJ. Mutation Analysis of X-linked Sideroblastic Anemia in a 12-Month-Old Boy by Massively Parallel Sequencing. Ann Lab Med 2018; 38:389-392. [PMID: 29611395 PMCID: PMC5895874 DOI: 10.3343/alm.2018.38.4.389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/26/2017] [Accepted: 02/20/2018] [Indexed: 11/19/2022] Open
Affiliation(s)
- Hui Jin Yu
- Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Young Ju Lee
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Won Shim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Deok Soo Kim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jung Yeon Shim
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Moon Soo Park
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hee Yeon Woo
- Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hyosoon Park
- Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Lim Jung
- Department of Pediatrics, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
| | - Min Jung Kwon
- Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
| |
Collapse
|
9
|
|
10
|
Abstract
Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid precursors from the bone marrow. Diamond-Blackfan anemia is a congenital form of PRCA. Acquired PRCA may be either a primary disorder or secondary to some other disorder or agent. Primary acquired PRCA is an autoimmune disorder that is frequently antibody-mediated. Myelodysplastic syndromes may also present with the morphologic appearance of PRCA. Secondary acquired PRCA may be associated with collagen vascular/autoimmune disorders such as systemic lupus erythematosus; lymphoproliferative disorders such as chronic lymphocytic leukemia or large granular lymphocyte leukemia; infections, particularly B19 parvovirus; thymoma and other solid tumors; or a variety of other disorders, drugs, or toxic agents. The therapeutic approach to PRCA typically involves immunosuppression, but specific pathogenic subtypes are associated with specific therapeutic approaches. Cyclosporine A, with or without concurrent corticosteroids, appears to be the single most effective immunosuppressive agent.
Collapse
|
11
|
Abstract
Pure red cell aplasia (PRCA) is a syndrome defined by a normocytic normochromic anemia with severe reticulocytopenia and marked reduction or absence of erythroid precursors from the bone marrow. Diamond-Blackfan anemia is a congenital form of PRCA. Acquired PRCA may be either a primary disorder or secondary to some other disorder or agent. Primary acquired PRCA is an autoimmune disorder that is frequently antibody-mediated. Myelodysplastic syndromes may also present with the morphologic appearance of PRCA. Secondary acquired PRCA may be associated with collagen vascular/autoimmune disorders such as systemic lupus erythematosus; lymphoproliferative disorders such as chronic lymphocytic leukemia or large granular lymphocyte leukemia; infections, particularly B19 parvovirus; thymoma and other solid tumors; or a variety of other disorders, drugs, or toxic agents. The therapeutic approach to PRCA typically involves immunosuppression, but specific pathogenic subtypes are associated with specific therapeutic approaches. Cyclosporine A, with or without concurrent corticosteroids, appears to be the single most effective immunosuppressive agent.
Collapse
MESH Headings
- Adrenal Cortex Hormones/therapeutic use
- Anemia, Diamond-Blackfan/drug therapy
- Anemia, Diamond-Blackfan/immunology
- Anemia, Diamond-Blackfan/pathology
- Autoimmune Diseases/drug therapy
- Autoimmune Diseases/immunology
- Autoimmune Diseases/pathology
- Cyclosporine/therapeutic use
- Humans
- Immunosuppressive Agents/therapeutic use
- Leukemia, Large Granular Lymphocytic/drug therapy
- Leukemia, Large Granular Lymphocytic/immunology
- Leukemia, Large Granular Lymphocytic/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Myelodysplastic Syndromes/drug therapy
- Myelodysplastic Syndromes/etiology
- Myelodysplastic Syndromes/immunology
- Myelodysplastic Syndromes/pathology
- Parvoviridae Infections/drug therapy
- Parvoviridae Infections/immunology
- Parvoviridae Infections/pathology
- Parvovirus B19, Human/immunology
- Thymoma/drug therapy
- Thymoma/immunology
- Thymoma/pathology
- Vasculitis/drug therapy
- Vasculitis/immunology
- Vasculitis/pathology
Collapse
Affiliation(s)
- Robert T Means
- Office of the Dean, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN
| |
Collapse
|
12
|
Barupala DP, Dzul SP, Riggs-Gelasco PJ, Stemmler TL. Synthesis, delivery and regulation of eukaryotic heme and Fe-S cluster cofactors. Arch Biochem Biophys 2016; 592:60-75. [PMID: 26785297 PMCID: PMC4784227 DOI: 10.1016/j.abb.2016.01.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/13/2016] [Accepted: 01/14/2016] [Indexed: 11/25/2022]
Abstract
In humans, the bulk of iron in the body (over 75%) is directed towards heme- or Fe-S cluster cofactor synthesis, and the complex, highly regulated pathways in place to accomplish biosynthesis have evolved to safely assemble and load these cofactors into apoprotein partners. In eukaryotes, heme biosynthesis is both initiated and finalized within the mitochondria, while cellular Fe-S cluster assembly is controlled by correlated pathways both within the mitochondria and within the cytosol. Iron plays a vital role in a wide array of metabolic processes and defects in iron cofactor assembly leads to human diseases. This review describes progress towards our molecular-level understanding of cellular heme and Fe-S cluster biosynthesis, focusing on the regulation and mechanistic details that are essential for understanding human disorders related to the breakdown in these essential pathways.
Collapse
Affiliation(s)
- Dulmini P Barupala
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Stephen P Dzul
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA
| | | | - Timothy L Stemmler
- Departments of Biochemistry and Molecular Biology, and Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA.
| |
Collapse
|
13
|
O'Grady MJ, Monavari AA, Cotter M, Murphy NP. Sideroblastic anaemia and primary adrenal insufficiency due to a mitochondrial respiratory chain disorder in the absence of mtDNA deletion. BMJ Case Rep 2015; 2015:bcr-2014-208514. [PMID: 25721834 DOI: 10.1136/bcr-2014-208514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A fatigued 8-year-old boy was found to have sideroblastic anaemia (haemoglobin 7.8 g/dL) which over time became transfusion dependent. Subtle neurological dysfunction, initially manifesting as mild spastic diplegia, was slowly progressive and ultimately led to wheelchair dependence. Elevated plasma lactate and urinary 3-methylglutaconate led to a muscle biopsy which confirmed partial complex IV deficiency. PCR in leucocytes and muscle was negative for mitochondrial DNA (mtDNA) deletions. Faltering growth prompted an insulin tolerance test which confirmed growth hormone sufficiency and adrenal insufficiency. Plasma renin was elevated and adrenal androgens were low, suggesting primary adrenal insufficiency. Glucocorticoid and mineralocorticoid replacement therapy was initiated. A renal tubular Fanconi syndrome and diabetes mellitus developed subsequently. Sideroblastic anaemia and primary adrenal insufficiency, both individually and collectively, are associated with mtDNA deletion; however, absence of the same does not exclude the possibility that sideroblastic anaemia and primary adrenal insufficiency are of mitochondrial origin.
Collapse
Affiliation(s)
- Michael J O'Grady
- Department of Paediatrics, Midland Regional Hospital, Mullingar, Ireland
| | - Ahmad A Monavari
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Dublin, Ireland
| | - Melanie Cotter
- Department of Paediatric Haematology, Children's University Hospital, Dublin, Ireland
| | - Nuala P Murphy
- Department of Paediatric Endocrinology, Children's University Hospital, Dublin, Ireland
| |
Collapse
|
14
|
Rollón N, Fernández-Jiménez MC, Moreno-Carralero MI, Murga-Fernández MJ, Morán-Jiménez MJ. Microcytic anemia in a pregnant woman: beyond iron deficiency. Int J Hematol 2014; 101:514-9. [PMID: 25547425 DOI: 10.1007/s12185-014-1723-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 01/19/2023]
Abstract
Sideroblastic anemias are a heterogeneous group of disorders characterized by anemia of varying severity and the presence of ringed sideroblasts in bone marrow. The most common form of inherited sideroblastic anemia is X-linked sideroblastic anemia (XLSA). In many XLSA patients, anemia responds variably to supplementation with pyridoxine (vitamin B6). We describe the case of a pregnant female with XLSA who had a novel mutation on the ALAS2 gene (c.1218G > T, p.Leu406Phe). Oral chelation therapy was contraindicated and high-dose vitamin B6 would have possible side effects in pregnancy. Serum hepcidin level was very low, indicating increased absorption of iron secondary to ineffective erythropoiesis. Therapy was begun with a low dose of pyridoxine that was increased post-partum. The patient's liver showed moderate iron deposits. During a subsequent 3-month period of pyridoxine supplementation, serum ferritin level and transferrin saturation decreased, hemoglobin content and serum hepcidin level normalized, and morphologic red cell abnormalities improved markedly. The patient responded well to treatment, showing the pyridoxine responsiveness of this novel ALAS2 mutation. The baby girl had the same mutation heterozygously, and although she was neither anemic nor showed abnormalities in a peripheral blood smear, she had a mild increment in RDW and her condition is now being followed.
Collapse
Affiliation(s)
- Noelia Rollón
- Department of Hematology, Complejo Hospitalario de Toledo, Hospital Virgen de la Salud, Avenida de Barber, 30, 45004, Toledo, Spain,
| | | | | | | | | |
Collapse
|
15
|
Wong WS, Wong HF, Cheng CK, Chang KO, Chan NPH, Ng MHL, Wong KF. Congenital sideroblastic anaemia with a novel frameshift mutation inSLC25A38. J Clin Pathol 2014; 68:249-51. [DOI: 10.1136/jclinpath-2014-202211] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
16
|
Kefala-Agoropoulou K, Roilides E, Lazaridou A, Karatza E, Farmaki E, Tsantali H, Augoustides-Savvopoulou P, Tsiouris J. Pearson syndrome in an infant heterozygous for C282Y allele of HFE gene. Hematology 2013; 12:549-53. [PMID: 17852457 DOI: 10.1080/10245330701400900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Pearson syndrome is a rare mitochondrial disorder characterized by sideroblastic anemia, liver disease, renal tubulopathy and exocrine pancreas deficiency. OBSERVATIONS We describe a female infant suffering from anemia since birth who gradually developed the complete picture of Pearson syndrome by 13 months. Iron overload was disproportionate to blood transfusions. The patient was heterozygous for HFE gene C282Y mutation (type I hemochromatosis). After an initial response to deferoxamine she presented with cutaneous zygomycosis and died after metabolic derangement and Pneumocystis jiroveci pneumonia. CONCLUSION This is the second case of a Pearson syndrome individual who was also heterozygous for HFE gene mutation C282Y published. It is also the second case report of a Pearson patient suffering from severe iron overload and liver disease that responded to therapy with deferoxamine.
Collapse
|
17
|
Horvathova M, Ponka P, Divoky V. Molecular basis of hereditary iron homeostasis defects. Hematology 2013; 15:96-111. [DOI: 10.1179/102453310x12583347009810] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Monika Horvathova
- Department of BiologyPalacky University, Hnevotinska 3, Olomouc 775 15, Czech Republic
| | - Prem Ponka
- Lady Davis Institute for Medical ResearchJewish General Hospital, and Departments of Physiology and Medicine, McGill University, Montreal, Quebec, Canada
| | - Vladimir Divoky
- Department of BiologyFaculty of Medicine Palacky University, Olomouc, Czech Republic, Department of Hemato-oncology, Faculty of Medicine Palacky University, Olomouc, Czech Republic
| |
Collapse
|
18
|
Abstract
Heme, which is composed of iron and the small organic molecule protoporphyrin, is an essential component of hemoglobin as well as a variety of physiologically important hemoproteins. During erythropoiesis, heme synthesis is induced before, and is essential for, globin synthesis. Although all cells possess the ability to synthesize heme, there are distinct differences between regulation of the pathway in developing erythroid cells and all other types of cells. Disorders that compromise the ability of the developing red cell to synthesize heme can have profound medical implications. The biosynthetic pathway for heme and key regulatory features are reviewed herein, along with specific human genetic disorders that arise from defective heme synthesis such as X-linked sideroblastic anemia and erythropoietic protoporphyria.
Collapse
Affiliation(s)
- Harry A Dailey
- Department of Microbiology, Department of Biochemistry and Molecular Biology, Biomedical and Health Sciences Institute, University of Georgia, Athens, GA 30602, USA.
| | | |
Collapse
|
19
|
Affiliation(s)
- Robert E Fleming
- Department of Pediatrics, Saint Louis University School of Medicine, St. Louis, USA
| | | |
Collapse
|
20
|
Sato K, Torimoto Y, Hosoki T, Ikuta K, Takahashi H, Yamamoto M, Ito S, Okamura N, Ichiki K, Tanaka H, Shindo M, Hirai K, Mizukami Y, Otake T, Fujiya M, Sasaki K, Kohgo Y. Loss of ABCB7 gene: pathogenesis of mitochondrial iron accumulation in erythroblasts in refractory anemia with ringed sideroblast with isodicentric (X)(q13). Int J Hematol 2011; 93:311-318. [PMID: 21380928 DOI: 10.1007/s12185-011-0786-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 11/28/2022]
Abstract
An isodicentric (X)(q13) (idicXq13) is a rare, acquired chromosomal abnormality originated by deletion of the long arm from Xq13 (Xq13-qter), and is found in female patients with hematological disorders involving increased ringed sideroblasts (RSs), which are characterized by mitochondrial iron accumulation around the erythroblast nucleus. The cause of increased RSs in idicXq13 patients is not fully understood. Here, we report the case of a 66-year-old female presenting with refractory anemia with ringed sideroblasts (RARS), and idicXq13 on G-banded analysis. We identify the loss of the ABCB7 (ATP-binding cassette subfamily B member-7) gene, which is located on Xq13 and is involved in mitochondrial iron transport to the cytosol, by fluorescent in situ hybridization (FISH) analysis and the decreased expression level of ABCB7 mRNA in the patient's bone marrow cells. Further FISH analyses showed that the ABCB7 gene is lost only on the active X-chromosome, not on the inactive one. We suggest that loss of ABCB7 due to deletion of Xq13-qter at idicXq13 formation may have contributed to the increased RSs in this patient. These findings suggest that loss of the ABCB7 gene may be a pathogenetic factor underlying mitochondrial iron accumulation in RARS patients with idicXq13.
Collapse
Affiliation(s)
- Kazuya Sato
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan.
| | - Yoshihiro Torimoto
- Oncology Center, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan
| | - Takaaki Hosoki
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Katsuya Ikuta
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Hiroyuki Takahashi
- Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan
| | - Masayo Yamamoto
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Satoshi Ito
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Naoka Okamura
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Kazuhiko Ichiki
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Hiroki Tanaka
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Motohiro Shindo
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | | | - Yusuke Mizukami
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Takaaki Otake
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Mikihiro Fujiya
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Kastunori Sasaki
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| | - Yutaka Kohgo
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2 jo 1 chome 1-1, Asahikawa, Hokkaido, 078-8510, Japan
| |
Collapse
|
21
|
Ducamp S, Kannengiesser C, Touati M, Garçon L, Guerci-Bresler A, Guichard JF, Vermylen C, Dochir J, Poirel HA, Fouyssac F, Mansuy L, Leroux G, Tertian G, Girot R, Heimpel H, Matthes T, Talbi N, Deybach JC, Beaumont C, Puy H, Grandchamp B. Sideroblastic anemia: molecular analysis of the ALAS2 gene in a series of 29 probands and functional studies of 10 missense mutations. Hum Mutat 2011; 32:590-7. [PMID: 21309041 DOI: 10.1002/humu.21455] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 01/04/2011] [Indexed: 02/02/2023]
Abstract
X-linked Sideroblastic Anemia (XLSA) is the most common genetic form of sideroblastic anemia, a heterogeneous group of disorders characterized by iron deposits in the mitochondria of erythroid precursors. XLSA is due to mutations in the erythroid-specific 5-aminolevulinate synthase (ALAS2) gene. Thirteen different ALAS2 mutations were identified in 16 out of 29 probands with sideroblastic anemia. One third of the patients were females with a highly skewed X-chromosome inactivation. The identification of seven novel mutations in the ALAS2 gene, six missense mutations, and one deletion in the proximal promoter extends the allelic heterogeneity of XSLA. Most of the missense mutations were predicted to be deleterious, and 10 of them, without any published functional characterization, were expressed in Escherichia coli. ALAS2 activities were assayed in vitro. Five missense mutations resulted in decreased enzymatic activity under standard conditions, and two other mutated proteins had decreased activity when assayed in the absence of exogenous pyridoxal phosphate and increased thermosensitivity. Although most amino acid substitutions result in a clearly decreased enzymatic activity in vitro, a few mutations have a more subtle effect on the protein that is only revealed by in vitro tests under specific conditions.
Collapse
Affiliation(s)
- Sarah Ducamp
- INSERM, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Martin FM, Xu X, von Löhneysen K, Gilmartin TJ, Friedman JS. SOD2 deficient erythroid cells up-regulate transferrin receptor and down-regulate mitochondrial biogenesis and metabolism. PLoS One 2011; 6:e16894. [PMID: 21326867 PMCID: PMC3033911 DOI: 10.1371/journal.pone.0016894] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 01/05/2011] [Indexed: 01/19/2023] Open
Abstract
Background Mice irradiated and reconstituted with hematopoietic cells lacking manganese superoxide dismutase (SOD2) show a persistent hemolytic anemia similar to human sideroblastic anemia (SA), including characteristic intra-mitochondrial iron deposition. SA is primarily an acquired, clonal marrow disorder occurring in individuals over 60 years of age with uncertain etiology. Methodology/Principal Findings To define early events in the pathogenesis of this murine model of SA, we compared erythroid differentiation of Sod2-/- and normal bone marrow cells using flow cytometry and gene expression profiling of erythroblasts. The predominant transcriptional differences observed include widespread down-regulation of mitochondrial metabolic pathways and mitochondrial biogenesis. Multiple nuclear encoded subunits of complexes I-IV of the electron transport chain, ATP synthase (complex V), TCA cycle and mitochondrial ribosomal proteins were coordinately down-regulated in Sod2-/- erythroblasts. Despite iron accumulation within mitochondria, we found increased expression of transferrin receptor, Tfrc, at both the transcript and protein level in SOD2 deficient cells, suggesting deregulation of iron delivery. Interestingly, there was decreased expression of ABCb7, the gene responsible for X-linked hereditary SA with ataxia, a component required for iron-sulfur cluster biogenesis. Conclusions/Significance These results indicate that in erythroblasts, mitochondrial oxidative stress reduces expression of multiple nuclear genes encoding components of the respiratory chain, TCA cycle and mitochondrial protein synthesis. An additional target of particular relevance for SA is iron:sulfur cluster biosynthesis. By decreasing transcription of components of cluster synthesis machinery, both iron utilization and regulation of iron uptake are impacted, contributing to the sideroblastic phenotype.
Collapse
Affiliation(s)
- Florent M. Martin
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Xiuling Xu
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Katharina von Löhneysen
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Timothy J. Gilmartin
- DNA Array Core Facility, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jeffrey S. Friedman
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
23
|
Camaschella C, Pagani A. Iron and erythropoiesis: a dual relationship. Int J Hematol 2010; 93:21-6. [PMID: 21170616 DOI: 10.1007/s12185-010-0743-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 11/30/2010] [Indexed: 01/13/2023]
Abstract
Iron is essential for cell life and especially for erythropoiesis which is the major body consumer of iron for red cell production. The study of genetic disorders of iron metabolism, the identification of iron transporters and of the role of hepcidin as the key regulator of systemic iron homeostasis have greatly contributed to our understanding of iron handling by the erythroid marrow. Spontaneous and engineered animal models of iron disorders have help to add further insights to the issue. A still incompletely understood aspect remains the regulation that erythropoiesis exerts on iron.
Collapse
Affiliation(s)
- Clara Camaschella
- Division of Genetics and Cell Biology, Università Vita-Salute e IRCCS San Raffaele, Via Olgettina 60, 20132 Milan, Italy.
| | | |
Collapse
|
24
|
Bartnikas TB, Campagna DR, Antiochos B, Mulhern H, Pondarré C, Fleming MD. Characterization of mitochondrial ferritin-deficient mice. Am J Hematol 2010; 85:958-60. [PMID: 20960432 DOI: 10.1002/ajh.21872] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
25
|
Zhang Y, Mikhael M, Xu D, Li Y, Soe-Lin S, Ning B, Li W, Nie G, Zhao Y, Ponka P. Lysosomal proteolysis is the primary degradation pathway for cytosolic ferritin and cytosolic ferritin degradation is necessary for iron exit. Antioxid Redox Signal 2010; 13:999-1009. [PMID: 20406137 DOI: 10.1089/ars.2010.3129] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cytosolic ferritins sequester and store iron, consequently protecting cells against iron-mediated free radical damage. However, the mechanisms of iron exit from the ferritin cage and reutilization are largely unknown. In a previous study, we found that mitochondrial ferritin (MtFt) expression led to a decrease in cytosolic ferritin. Here we showed that treatment with inhibitors of lysosomal proteases largely blocked cytosolic ferritin loss in both MtFt-expressing and wild-type cells. Moreover, cytosolic ferritin in cells treated with inhibitors of lysosomal proteases was found to store more iron than did cytosolic ferritins in untreated cells. The prevention of cytosolic ferritin degradation in MtFt-expressing cells significantly blocked iron mobilization from the protein cage induced by MtFt expression. These studies also showed that blockage of cytosolic ferritin loss by leupeptin resulted in decreased cytosolic ferritin synthesis and prolonged cytosolic ferritin stability, potentially resulting in diminished iron availability. Lastly, we found that proteasomes were responsible for cytosolic ferritin degradation in cells pretreated with ferric ammonium citrate. Thus, the current studies suggest that cytosolic ferritin degradation precedes the release of iron in MtFt-expressing cells; that MtFt-induced cytosolic ferritin decrease is partially preventable by lysosomal protease inhibitors; and that both lysosomal and proteasomal pathways may be involved in cytosolic ferritin degradation.
Collapse
Affiliation(s)
- Yinghui Zhang
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Bergmann AK, Campagna DR, McLoughlin EM, Agarwal S, Fleming MD, Bottomley SS, Neufeld EJ. Systematic molecular genetic analysis of congenital sideroblastic anemia: evidence for genetic heterogeneity and identification of novel mutations. Pediatr Blood Cancer 2010; 54:273-8. [PMID: 19731322 PMCID: PMC2843911 DOI: 10.1002/pbc.22244] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Sideroblastic anemias are heterogeneous congenital and acquired bone marrow disorders characterized by pathologic iron deposits in mitochondria of erythroid precursors. Among the congenital sideroblastic anemias (CSAs), the most common form is X-linked sideroblastic anemia, due to mutations in 5-aminolevulinate synthase (ALAS2). A novel autosomal recessive CSA, caused by mutations in the erythroid specific mitochondrial transporter SLC25A38, was recently defined. Other known etiologies include mutations in genes encoding the thiamine transporter SLC19A2, the RNA-modifying enzyme pseudouridine synthase 1 (PUS1), a mitochondrial ATP-binding cassette transporter (ABCB7), glutaredoxin 5 (GLRX5), as well as mitochondrial DNA deletions. Despite these known diverse causes, in a substantial portion of CSA cases a presumed genetic defect remains unknown. PROCEDURE In the context of the recent discovery of SLC25A38 as a major novel cause, we systematically analyzed a large cohort of previously unreported CSA patients. Sixty CSA probands (28 females, 32 males) were examined for ALAS2, SLC25A38, PUS1, GLRX5, and ABCB7 mutations. SLC19A2 and mitochondrial DNA were only analyzed if characteristic syndromic features were apparent. RESULTS Twelve probands had biallelic mutations in SLC25A38. Seven ALAS2 mutations were detected in eight sporadic CSA cases, two being novel. We also identified a novel homozygous null PUS1 mutation and novel mitochondrial DNA deletions in two patients with Pearson syndrome. No mutations were encountered in GLRX5, ABCB7, or SLC19A2. CONCLUSIONS The remaining undefined probands (43%) can be grouped according to gender, family, and clinical characteristics, suggesting novel X-linked and autosomal recessive forms of CSA.
Collapse
Affiliation(s)
- Anke K. Bergmann
- Division of Hematology/Oncology, Children’s Hospital Boston and Harvard Medical School, Boston, MA
| | - Dean R. Campagna
- Department of Pathology, Children’s Hospital Boston and Harvard Medical School, Boston, MA
| | - Erin M. McLoughlin
- Division of Hematology/Oncology, Children’s Hospital Boston and Harvard Medical School, Boston, MA
| | - Suneet Agarwal
- Division of Hematology/Oncology, Children’s Hospital Boston and Harvard Medical School, Boston, MA, Dana Farber Cancer Institute, Boston, MA
| | - Mark D. Fleming
- Department of Pathology, Children’s Hospital Boston and Harvard Medical School, Boston, MA
| | - Sylvia S. Bottomley
- Hematology-Oncology Section, University of Oklahoma College of Medicine, Oklahoma City, OK
| | - Ellis J. Neufeld
- Division of Hematology/Oncology, Children’s Hospital Boston and Harvard Medical School, Boston, MA, Dana Farber Cancer Institute, Boston, MA
| |
Collapse
|
27
|
Abstract
Treatment of mitochondrial disorders (MIDs) is a challenge since there is only symptomatic therapy available and since only few randomized and controlled studies have been carried out, which demonstrate an effect of some of the symptomatic or supportive measures available. Symptomatic treatment of MIDs is based on mainstay drugs, blood transfusions, hemodialysis, invasive measures, surgery, dietary measures, and physiotherapy. Drug treatment may be classified as specific (treatment of epilepsy, headache, dementia, dystonia, extrapyramidal symptoms, Parkinson syndrome, stroke-like episodes, or non-neurological manifestations), non-specific (antioxidants, electron donors/acceptors, alternative energy sources, cofactors), or restrictive (avoidance of drugs known to be toxic for mitochondrial functions). Drugs which more frequently than in the general population cause side effects in MID patients include steroids, propofol, statins, fibrates, neuroleptics, and anti-retroviral agents. Invasive measures include implantation of a pacemaker, biventricular pacemaker, or implantable cardioverter defibrillator, or stent therapy. Dietary measures can be offered for diabetes, hyperlipidemia, or epilepsy (ketogenic diet, anaplerotic diet). Treatment should be individualized because of the peculiarities of mitochondrial genetics. Despite limited possibilities, symptomatic treatment should be offered to MID patients, since it can have a significant impact on the course and outcome.
Collapse
|
28
|
Abstract
Inherited sideroblastic anemia comprises several rare anemias due to heterogeneous genetic lesions, all characterized by the presence of ringed sideroblasts in the bone marrow. This morphological aspect reflects abnormal mitochondrial iron utilization by the erythroid precursors. The most common X-linked sideroblastic anemia (XLSA), due to mutations of the first enzyme of the heme synthetic pathway, delta-aminolevulinic acid synthase 2 (ALAS2), has linked heme deficiency to mitochondrial iron accumulation. The identification of other genes, such as adenosine triphosphate (ATP) binding cassette B7 (ABCB7) and glutaredoxin 5 (GLRX5), has strengthened the role of iron sulfur cluster biogenesis in sideroblast formation and revealed a complex interplay between pathways of mitochondrial iron utilization and cytosolic iron sensing by the iron-regulatory proteins (IRPs). As recently occurred with the discovery of the SLC25A38-related sideroblastic anemia, the identification of the genes responsible for as yet uncharacterized forms will provide further insights into mitochondrial iron metabolism of erythroid cells and the pathophysiology of sideroblastic anemia.
Collapse
Affiliation(s)
- Clara Camaschella
- Vita-Salute University and San Raffaele Scientific Institute, Milan, Italy.
| |
Collapse
|
29
|
Lu Z, Nie G, Li Y, Soe-Lin S, Tao Y, Cao Y, Zhang Z, Liu N, Ponka P, Zhao B. Overexpression of mitochondrial ferritin sensitizes cells to oxidative stress via an iron-mediated mechanism. Antioxid Redox Signal 2009; 11:1791-803. [PMID: 19271990 DOI: 10.1089/ars.2008.2306] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mitochondrial ferritin (MtFt) is a newly identified H-ferritin-like protein expressed only in mitochondria. Previous studies have shown that its overexpression markedly affects intracellular iron homeostasis and rescues defects caused by frataxin deficiency. To assess how MtFt exerts its function under oxidative stress conditions, MtFt overexpressing cells were treated with tert-butyl-hydroperoxide (tBHP), and the effects of MtFt expression on cell survival and iron homeostasis were examined. We found that MtFt expression was associated with decreased mitochondrial metabolic activity and reduced glutathione levels as well as a concomitant increase in reactive oxygen species levels and apoptosis. Moreover, mechanistic studies demonstrated that tBHP treatment led to a prolonged decrease in cytosolic ferritins levels in MtFt-expressing cells, while ferritin levels recovered to basal levels in control counterparts. tBHP treatment also resulted in elevated transferrin receptors, followed by more iron acquisition in MtFt expressing cells. The high molecular weight desferrioxamine, targeting to lysosomes, as well as the hydrophobic iron chelator salicylaldehyde isonicotinoyl hydrazone significantly attenuated tBHP-induced cell damage. In conclusion, the current study indicates that both the newly acquired iron from the extracellular environment and internal iron redistribution from ferritin degradation may be responsible for the increased sensitivity to oxidative stress in MtFt-expressing cells.
Collapse
Affiliation(s)
- Zhongbing Lu
- State Key Laboratory of Brain and Recognition Laboratory, Institute of Biophysics, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Mori M, Nakamoto S, Akifuji Y, Tanaka T, Komatsu N, Hatake K, Ozawa K. Familial sideroblastic anemia associated with cardiac atrial septal defect. Am J Hematol 2009; 84:451-2. [PMID: 19425066 DOI: 10.1002/ajh.21425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
31
|
Mutations in mitochondrial carrier family gene SLC25A38 cause nonsyndromic autosomal recessive congenital sideroblastic anemia. Nat Genet 2009; 41:651-3. [PMID: 19412178 DOI: 10.1038/ng.359] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 02/17/2009] [Indexed: 01/14/2023]
Abstract
The sideroblastic anemias are a heterogeneous group of congenital and acquired hematological disorders whose morphological hallmark is the presence of ringed sideroblasts--bone marrow erythroid precursors containing pathologic iron deposits within mitochondria. Here, by positional cloning, we define a previously unknown form of autosomal recessive nonsyndromic congenital sideroblastic anemia, associated with mutations in the gene encoding the erythroid specific mitochondrial carrier family protein SLC25A38, and demonstrate that SLC25A38 is important for the biosynthesis of heme in eukaryotes.
Collapse
|
32
|
Abstract
Nutritional anemias are important because they are easily reversed and because their underlying causes, most often unrelated to dietary intake, require individualized assessment. Iron-deficiency anemia (IDA) usually results from iron losses accompanying chronic bleeding, including loss to intestinal parasites, or from gastric disorders or malabsorption in the elderly. Cobalamin-deficiency anemia, the only nutritional anemia with predilection for the elderly, nearly always stems from failure of intrinsic factor (IF)-related absorption. Folate-deficiency anemia, the only nutritional anemia usually caused by poor intake, has nearly disappeared in countries that fortify food with folic acid. Copper-deficiency anemia, which usually results from malabsorptive disorders or from medical or nutritional interventions that provide inadequate copper or excess zinc, is uncommon but increasingly recognized. The prevalences of nutritional anemias, which are not always distinguished from non-anemic deficiency, are uncertain. The mean corpuscular volume (MCV) provides an essential diagnostic tool leading to judicious matching of relevant biochemical changes with relevant anemia. Nutritional anemias usually feature abnormal MCV, whereas the predominant anemias in the aged, especially the anemias of chronic disease/chronic inflammation (ACD/ACI), of renal failure, and of unknown causes, are typically normocytic.
Collapse
Affiliation(s)
- Ralph Carmel
- Departments of Medicine, New York Methodist Hospital, 506 Sixth Street, Brooklyn, NY 11215, USA.
| |
Collapse
|
33
|
Levi S, Rovida E. The role of iron in mitochondrial function. Biochim Biophys Acta Gen Subj 2008; 1790:629-36. [PMID: 18948172 DOI: 10.1016/j.bbagen.2008.09.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 07/30/2008] [Accepted: 09/23/2008] [Indexed: 01/09/2023]
Abstract
BACKGROUND Iron is an essential element for life, as it is a cofactor for enzymes involved in many metabolic processes, but it can also be harmful, since its excess is thought to enhance the production of reactive oxygen species and induce oxidative damage. Iron is transformed into its biologically available form in the mitochondrion by the iron-sulfur (Fe/S) cluster and heme synthesis pathways. During the past decade, substantial progress has been made in the elucidation of iron-linked mechanisms that occur in the mitochondrion, demonstrating the crucial role played by this organelle in maintaining cellular iron homeostasis. GENERAL SIGNIFICANCE This review summarizes current knowledge of the mechanisms underlying iron trafficking in mitochondria and how it is handled inside the organelle. Relevant updates with regard to the Fe/S cluster and heme biosynthetic pathways, as well as the relationship between mitochondrial iron homeostasis impairment and related diseases, are also discussed.
Collapse
Affiliation(s)
- Sonia Levi
- Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milano, Italy.
| | | |
Collapse
|
34
|
Abstract
Mouse models have proven invaluable for understanding erythropoiesis. Here, we describe an autosomal recessive, inherited anemia in the mouse mutant hem6. Hematologic and transplantation analyses reveal a mild, congenital, hypochromic, microcytic anemia intrinsic to the hematopoietic system that is associated with a decreased red blood cell zinc protoporphyrin to heme ratio, indicative of porphyrin insufficiency. Intercross matings show that hem6 can suppress the porphyric phenotype of mice with erythropoietic protoporphyria (EPP). Furthermore, iron uptake studies in hem6 reticulocytes demonstrate defective incorporation of iron into heme that can be partially corrected by the addition of porphyrin precursors. Gene expression and enzymatic assays indicate that erythroid 5-aminolevulinic acid synthase (Alas2) is decreased in hem6 animals, suggesting a mechanism that could account for the anemia. Overall, these data lead to the hypothesis that hem6 encodes a protein that directly or indirectly regulates the expression of Alas2.
Collapse
|
35
|
Abstract
Sideroblastic anaemia includes a heterogeneous group of rare conditions, characterized by decreased haem synthesis and mitochondrial iron overload, which are diagnosed by the presence of ringed sideroblasts in the bone marrow aspirate. The most frequent form is X-linked sideroblastic anaemia, caused by mutations of delta-aminolevulinic acid synthase 2 (ALAS2), the enzyme that catalyses the first and regulatory step of haem synthesis in erythroid precursors and is post-transcriptionally controlled by the iron regulatory proteins. Impaired haem production causes variable degrees of anaemia and mitochondrial iron accumulation as ringed sideroblasts. The heterogeneity and complexity of sideroblastic anaemia is explained by an increasing number of recognized molecular defects. New forms have been recognized as being linked to the deficient function of mitochondrial proteins involved in iron-sulphur cluster biogenesis, such as ABCB7 and GLRX5, which are extremely rare but represent important biological models. Local mitochondrial iron overload is present in all sideroblastic anaemias, whereas systemic iron overload occurs only in the forms because of primary or secondary deficiency of ALAS2.
Collapse
Affiliation(s)
- Clara Camaschella
- Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milan, Italy.
| |
Collapse
|
36
|
Body iron metabolism and pathophysiology of iron overload. Int J Hematol 2008; 88:7-15. [PMID: 18594779 PMCID: PMC2516548 DOI: 10.1007/s12185-008-0120-5] [Citation(s) in RCA: 357] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 06/02/2008] [Indexed: 02/06/2023]
Abstract
Iron is an essential metal for the body, while excess iron accumulation causes organ dysfunction through the production of reactive oxygen species. There is a sophisticated balance of body iron metabolism of storage and transport, which is regulated by several factors including the newly identified peptide hepcidin. As there is no passive excretory mechanism of iron, iron is easily accumulated when exogenous iron is loaded by hereditary factors, repeated transfusions, and other diseased conditions. The free irons, non-transferrin-bound iron, and labile plasma iron in the circulation, and the labile iron pool within the cells, are responsible for iron toxicity. The characteristic features of advanced iron overload are failure of vital organs such as liver and heart in addition to endocrine dysfunctions. For the estimation of body iron, there are direct and indirect methods available. Serum ferritin is the most convenient and widely available modality, even though its specificity is sometimes problematic. Recently, new physical detection methods using magnetic resonance imaging and superconducting quantum interference devices have become available to estimate iron concentration in liver and myocardium. The widely used application of iron chelators with high compliance will resolve the problems of organ dysfunction by excess iron and improve patient outcomes.
Collapse
|
37
|
|
38
|
Choung HS, Kim HJ, Jung CW, Kim SH. Identification of a Hemizygous R170H Mutation in the ALAS2Gene in a Young Male Patient with X-linked Sideroblastic Anemia. THE KOREAN JOURNAL OF HEMATOLOGY 2008. [DOI: 10.5045/kjh.2008.43.2.118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Hee-Suk Choung
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hee-Jin Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chul Won Jung
- Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sun-Hee Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| |
Collapse
|
39
|
Hodges VM, Rainey S, Lappin TR, Maxwell AP. Pathophysiology of anemia and erythrocytosis. Crit Rev Oncol Hematol 2007; 64:139-58. [PMID: 17656101 DOI: 10.1016/j.critrevonc.2007.06.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 03/02/2007] [Accepted: 06/12/2007] [Indexed: 10/23/2022] Open
Abstract
An increasing understanding of the process of erythropoiesis raises some interesting questions about the pathophysiology, diagnosis and treatment of anemia and erythrocytosis. The mechanisms underlying the development of many of the erythrocytoses, previously characterised as idiopathic, have been elucidated leading to an increased understanding of oxygen homeostasis. Characterisation of anemia and erythrocytosis in relation to serum erythropoietin levels can be a useful addition to clinical diagnostic criteria and provide a rationale for treatment with erythropoiesis stimulating agents (ESAs). Recombinant human erythropoietin as well as other ESAs are now widely used to treat anemias associated with a range of conditions, including chronic kidney disease, chronic inflammatory disorders and cancer. There is also heightened awareness of the potential abuse of ESAs to boost athletic performance in competitive sport. The discovery of erythropoietin receptors outside of the erythropoietic compartment may herald future applications for ESAs in the management of neurological and cardiac diseases. The current controversy concerning optimal hemoglobin levels in chronic kidney disease patients treated with ESAs and the potential negative clinical outcomes of ESA treatment in cancer reinforces the need for cautious evaluation of the pleiotropic effects of ESAs in non-erythroid tissues.
Collapse
Affiliation(s)
- Vivien M Hodges
- Haematology Research Group, Centre for Cancer Research and Cell Biology, Queen's University, Belfast, United Kingdom.
| | | | | | | |
Collapse
|
40
|
Finsterer J. Hematological manifestations of primary mitochondrial disorders. Acta Haematol 2007; 118:88-98. [PMID: 17637511 DOI: 10.1159/000105676] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 05/08/2007] [Indexed: 01/21/2023]
Abstract
At onset mitochondrial disorders (MID) frequently manifest as a mono-organic problem but turn into multisystem disease during the disease course in most of the cases. Organs/tissues most frequently affected in MID are the cerebrum, peripheral nerves, and the skeletal muscle. Additionally, most of the inner organs may be affected alone or in combination. Hematological manifestations of MID include aplastic, megaloblastic, or sideroblastic anemia, leukopenia, neutropenia, thrombocytopenia, or pancytopenia. In single cases either permanent or recurrent eosinophilia has been observed. Hematological abnormalities may occur together with syndromic or nonsyndromic MIDs. Syndromic MIDs, in which hematological manifestations predominate, are the Pearson syndrome (pancytopenia), Kearns-Sayre syndrome (anemia), Barth syndrome (neutropenia), and the autosomal recessive mitochondrial myopathy, lactic acidosis and sideroblastic anemia syndrome. In single cases with Leigh's syndrome, MERRF (myoclonic epilepsy and ragged-red fiber) syndrome, Leber's hereditary optic neuropathy, and Friedreich's ataxia anemia has been described. Anemia, leukopenia, thrombocytopenia, eosinophilia, or pancytopenia can frequently also be found in nonsyndromic MIDs with or without involvement of other tissues. Therapy of blood cell involvement in MID comprises application of antioxidants, vitamins, iron, bone marrow-stimulating factors, or substitution of cells.
Collapse
|
41
|
Steensma DP, Hecksel KA, Porcher JC, Lasho TL. Candidate gene mutation analysis in idiopathic acquired sideroblastic anemia (refractory anemia with ringed sideroblasts). Leuk Res 2007; 31:623-8. [PMID: 16870250 DOI: 10.1016/j.leukres.2006.06.005] [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] [Received: 05/17/2006] [Revised: 06/02/2006] [Accepted: 06/09/2006] [Indexed: 11/18/2022]
Abstract
BACKGROUND For most cases of idiopathic acquired sideroblastic anemia (IASA), the molecular pathogenesis is unknown, despite the consistent morphological signature of abundant pathological ringed sideroblasts with their characteristic iron-engorged mitochondria. Moderately elevated free erythrocyte protoporphyrin (FEP) levels have been described in IASA, suggesting that the activity of ferrochelatase, the enzyme that catalyzes the final step in heme biosynthesis (incorporation of ferrous iron into protoporphyrin), might be diminished in erythroid progenitor cells from IASA patients. METHODS We confirmed FEP elevation in IASA, then pursued a candidate gene approach that included screening the gene encoding ferrochelatase, FECH, for promoter and coding region mutations and mRNA expression changes in bone marrow from 37 patients with IASA. RESULTS The analytical techniques employed detected mutations in a test cohort of previously undiagnosed patients with biochemical evidence for erythropoietic protoporphyria, a condition resulting from germline mutations in FECH, but somatic missense mutations of FECH and its promoter were not observed in IASA patients. FECH was modestly overexpressed in progenitor cells from patients with IASA, compared with MDS patients without sideroblasts and healthy controls. In addition, we analyzed ABCB7 and PUS1, genes implicated in congenital sideroblastic anemia syndromes, but again found no coding mutations in acquired cases. CONCLUSION We conclude that acquired mutations in the factors currently known to cause inherited sideroblastic anemias are uncommon in IASA.
Collapse
Affiliation(s)
- David P Steensma
- Division of Hematology, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
| | | | | | | |
Collapse
|
42
|
Pondarre C, Campagna DR, Antiochos B, Sikorski L, Mulhern H, Fleming MD. Abcb7, the gene responsible for X-linked sideroblastic anemia with ataxia, is essential for hematopoiesis. Blood 2006; 109:3567-9. [PMID: 17192398 PMCID: PMC1852240 DOI: 10.1182/blood-2006-04-015768] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
X-linked sideroblastic anemia with ataxia (XLSA/A) is a rare syndromic form of inherited sideroblastic anemia associated with spinocerebellar ataxia, and is due to mutations in the mitochondrial ATP-binding cassette transporter Abcb7. Here, we show that Abcb7 is essential for hematopoiesis and formally demonstrate that XLSA/A is due to partial loss of function mutations in Abcb7 that directly or indirectly inhibit heme biosynthesis.
Collapse
Affiliation(s)
- Corinne Pondarre
- Department of Pathology, Children's Hospital Boston, 320 Longwood Avenue, Boston, MA 02115, USA
| | | | | | | | | | | |
Collapse
|
43
|
Cavadini P, Biasiotto G, Poli M, Levi S, Verardi R, Zanella I, Derosas M, Ingrassia R, Corrado M, Arosio P. RNA silencing of the mitochondrial ABCB7 transporter in HeLa cells causes an iron-deficient phenotype with mitochondrial iron overload. Blood 2006; 109:3552-9. [PMID: 17192393 DOI: 10.1182/blood-2006-08-041632] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Abstract
X-linked sideroblastic anemia with ataxia (XLSA/A) is caused by defects of the transporter ABCB7 and is characterized by mitochondrial iron deposition and excess of protoporphyrin in erythroid cells. We describe ABCB7 silencing in HeLa cells by performing sequential transfections with siRNAs. The phenotype of the ABCB7-deficient cells was characterized by a strong reduction in proliferation rate that was not rescued by iron supplementation, by evident signs of iron deficiency, and by a large approximately 6-fold increase of iron accumulation in the mitochondria that was poorly available to mitochondrial ferritin. The cells showed an increase of protoporphyrin IX, a higher sensitivity to H2O2 toxicity, and a reduced activity of mitochondrial superoxide dismutase 2 (SOD2), while the activity of mitochondrial enzymes, such as citrate synthase or succinate dehydrogenase, and ATP content were not decreased. In contrast, aconitase activity, particularly that of the cytosolic, IRP1 form, was reduced. The results support the hypothesis that ABCB7 is involved in the transfer of iron from mitochondria to cytosol, and in the maturation of cytosolic Fe/S enzymes. In addition, the results indicate that anemia in XLSA/A is caused by the accumulation of iron in a form that is not readily usable for heme synthesis.
Collapse
Affiliation(s)
- Patrizia Cavadini
- Dipartimento Materno Infantile e Tecnologie Biomediche, University of Brescia, Spedali Civili, Viale Europa 11, 25123 Brescia, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
Iron-sulfur (Fe/S) clusters require a complex set of proteins to become assembled and incorporated into apoproteins in a living cell. Researchers have described three distinct assembly systems in eukaryotes that are involved in the maturation of cellular Fe/S proteins. Mitochondria are central for biogenesis. They contain the ISC-the iron-sulfur cluster assembly machinery that was inherited from a similar system of eubacteria in evolution and is involved in biogenesis of all cellular Fe/S proteins. The basic principle of mitochondrial (and bacterial) Fe/S protein maturation is the synthesis of the Fe/S cluster on a scaffold protein before the cluster is transferred to apoproteins. Biogenesis of cytosolic and nuclear Fe/S proteins is facilitated by the cytosolic iron-sulfur protein assembly (CIA) apparatus. This process requires the participation of mitochondria that export a still unknown component via the ISC export machinery, including an ABC transporter.
Collapse
Affiliation(s)
- Roland Lill
- Institut für Zytobiologie, Philipps Universität Marburg, 35037 Marburg, Germany.
| | | |
Collapse
|
45
|
Miotto G, Tessaro S, Rotta GA, Bonatto D. In silico analyses of Fsf1 sequences, a new group of fungal proteins orthologous to the metazoan sideroblastic anemia-related sideroflexin family. Fungal Genet Biol 2006; 44:740-53. [PMID: 17240176 DOI: 10.1016/j.fgb.2006.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 11/16/2006] [Accepted: 12/11/2006] [Indexed: 02/01/2023]
Abstract
Sideroblastic anemias are pathologies observed in metazoan species characterized by accumulation of iron in the mitochondria (sideroblasts), defective erythropoiesis, and iron overload. Some genes have been associated with sideroblastic anemia, e.g. delta-aminolevulinic acid synthase gene (e-ALAS2). Recently, a new sideroblastic-associated protein family was discovered in metazoans and termed sideroflexin (Sfxn). The metazoan Sfxn family comprises five groups of paralogous proteins, present in mitochondria and whose functions are unknown. Using an in silico approach, we have identified and characterized new sideroflexin sequences from the genomes of different fungal species. An in-depth phylogenetic analysis of these new fungal Sfxn sequences (termed Fsf1p) showed that they form a distinct clade within the metazoan Sfxn family. Hydrophobic cluster analysis and transmembrane topological mapping allowed us to compare conserved regions among Fsf1 and Sfxn proteins. The results indicate that Fsf1 probably belongs to an ancient, mitochondrial group of proteins, necessary to maintain the homeostasis of iron within this organelle.
Collapse
Affiliation(s)
- Greice Miotto
- Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), Caxias do Sul, RS, Brazil
| | | | | | | |
Collapse
|
46
|
Abstract
Iron is an essential element that is toxic when it accumulates in excess. Intricate regulatory mechanisms have evolved to maintain iron homeostasis within cells and between different tissues of complex organisms. This review discusses the proteins involved in iron transport and storage and their regulation in health and disease.
Collapse
Affiliation(s)
- Adriana Donovan
- Children's Hospital Boston, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | | | | |
Collapse
|
47
|
Martin FM, Bydlon G, Friedman JS. SOD2-deficiency sideroblastic anemia and red blood cell oxidative stress. Antioxid Redox Signal 2006; 8:1217-25. [PMID: 16910769 DOI: 10.1089/ars.2006.8.1217] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Iron overload is a feature of an array of human disorders such as sideroblastic anemias, a heterogeneous group of erythropoietic disorders without identified cause in most cases. However, sideroblastic anemias appear to result from a disturbance at the interface between mitochondrial function and iron metabolism. A defining feature is excessive iron deposition within mitochondria of developing red cells, the consequences of which are an increase in cellular free radicals production, increased damage to proteins, and reduced cell survival. Because of its mitochondrial location, superoxide dismutase (SOD2) is the principal defense against the toxicity of superoxide anions generated by the oxidative phosphorylation. We have used hematopoietic stem cell transplantation to study blood cells lacking SOD2. We became interested in the role SOD2 plays in the metabolism of superoxide anions during erythroid development, as anemia is the major phenotype in transplanted animals. Our exploration of this model suggests that oxidative stress-and in particular, mitochondrial- derived oxidants-plays an important role in the pathogenesis of the human disorder, sideroblastic anemia. Here we review the relation between mitochondrial dysfunction and sideroblastic anemia, describe several methods for assessing oxidative damage to mature or developing red cells, present data on, and discuss the potential of antioxidant therapy for this disorder.
Collapse
Affiliation(s)
- Florent M Martin
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | |
Collapse
|
48
|
Ajioka RS, Phillips JD, Kushner JP. Biosynthesis of heme in mammals. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:723-36. [PMID: 16839620 DOI: 10.1016/j.bbamcr.2006.05.005] [Citation(s) in RCA: 341] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 05/10/2006] [Accepted: 05/11/2006] [Indexed: 11/30/2022]
Abstract
Most iron in mammalian systems is routed to mitochondria to serve as a substrate for ferrochelatase. Ferrochelatase inserts iron into protoporphyrin IX to form heme which is incorporated into hemoglobin and cytochromes, the dominant hemoproteins in mammals. Tissue-specific regulatory features characterize the heme biosynthetic pathway. In erythroid cells, regulation is mediated by erythroid-specific transcription factors and the availability of iron as Fe/S clusters. In non-erythroid cells the pathway is regulated by heme-mediated feedback inhibition. All of the enzymes in the heme biosynthetic pathway have been crystallized and the crystal structures have permitted detailed analyses of enzyme mechanisms. All of the genes encoding the heme biosynthetic enzymes have been cloned and mutations of these genes are responsible for a group of human disorders designated the porphyrias and for X-linked sideroblastic anemia. The biochemistry, structural biology and the mechanisms of tissue-specific regulation are presented in this review along with the key features of the porphyric disorders.
Collapse
Affiliation(s)
- Richard S Ajioka
- Department of Internal Medicine, Division of Hematology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | | | | |
Collapse
|
49
|
Nie G, Chen G, Sheftel AD, Pantopoulos K, Ponka P. In vivo tumor growth is inhibited by cytosolic iron deprivation caused by the expression of mitochondrial ferritin. Blood 2006; 108:2428-34. [PMID: 16757684 DOI: 10.1182/blood-2006-04-018341] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mitochondrial ferritin (MtFt) is a mitochondrial iron-storage protein whose function and regulation is largely unknown. Our previous results have shown that MtFt overexpression markedly affects intracellular iron homeostasis in mammalian cells. Using tumor xenografts, we examined the effects of MtFt overexpression on tumor iron metabolism and growth. The expression of MtFt dramatically reduced implanted tumor growth in nude mice. Mitochondrial iron deposition in MtFt-expressing tumors was directly observed by transmission electron microscopy. A cytosolic iron starvation phenotype in MtFt-expressing tumors was revealed by increased RNA-binding activity of iron regulatory proteins, and concomitantly both an increase in transferrin receptor levels and a decrease in cytosolic ferritin. MtFt overexpression also led to decreases in total cellular heme content and heme oxygenase-1 levels. In addition, elevated MtFt in tumors was also associated with a decrease in total aconitase activity and lower frataxin protein level. In conclusion, our study shows that high MtFt levels can significantly affect tumor iron homeostasis by shunting iron into mitochondria; iron scarcity resulted in partially deficient heme and iron-sulfur cluster synthesis. It is likely that deprivation of iron in the cytosol is the cause for the significant inhibition of xenograft tumor growth.
Collapse
Affiliation(s)
- Guangjun Nie
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital and Department of Physiology, McGill University, 3755 Cote Ste-Catherine Rd, Montreal, QC H3T 1E2, Canada
| | | | | | | | | |
Collapse
|
50
|
Wallander ML, Leibold EA, Eisenstein RS. Molecular control of vertebrate iron homeostasis by iron regulatory proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:668-89. [PMID: 16872694 PMCID: PMC2291536 DOI: 10.1016/j.bbamcr.2006.05.004] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Revised: 05/09/2006] [Accepted: 05/10/2006] [Indexed: 02/06/2023]
Abstract
Both deficiencies and excesses of iron represent major public health problems throughout the world. Understanding the cellular and organismal processes controlling iron homeostasis is critical for identifying iron-related diseases and in advancing the clinical treatments for such disorders of iron metabolism. Iron regulatory proteins (IRPs) 1 and 2 are key regulators of vertebrate iron metabolism. These RNA binding proteins post-transcriptionally control the stability or translation of mRNAs encoding proteins involved in iron homeostasis thereby controlling the uptake, utilization, storage or export of iron. Recent evidence provides insight into how IRPs selectively control the translation or stability of target mRNAs, how IRP RNA binding activity is controlled by iron-dependent and iron-independent effectors, and the pathological consequences of dysregulation of the IRP system.
Collapse
Affiliation(s)
- Michelle L. Wallander
- Department of Oncological Sciences, University of Utah, 15N. 2030E., Salt Lake City, UT 84112, USA
- Eccles Program in Human Molecular Biology and Genetics, University of Utah, 15N. 2030E., Salt Lake City, UT 84112, USA
| | - Elizabeth A. Leibold
- Department of Medicine, University of Utah, 15N. 2030E., Salt Lake City, UT 84112, USA
- Department of Oncological Sciences, University of Utah, 15N. 2030E., Salt Lake City, UT 84112, USA
- Eccles Program in Human Molecular Biology and Genetics, University of Utah, 15N. 2030E., Salt Lake City, UT 84112, USA
| | - Richard S. Eisenstein
- Department of Nutritional Sciences, University of Wisconsin, 1415 Linden Drive, Madison, WI 53706, USA
- Corresponding author. Tel.: +1 608 262 5830. E-mail address: (R.S. Eisenstein)
| |
Collapse
|