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Kim HR, Kang MG, Lee YE, Na BR, Noh MS, Yang SH, Shin JH, Shin MG. Spectrum of mitochondrial genome instability and implication of mitochondrial haplogroups in Korean patients with acute myeloid leukemia. Blood Res 2018; 53:240-249. [PMID: 30310792 PMCID: PMC6170299 DOI: 10.5045/br.2018.53.3.240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 08/01/2018] [Accepted: 08/05/2018] [Indexed: 11/17/2022] Open
Abstract
Background Mitochondrial DNA (mtDNA) mutations may regulate the progression and chemosensitivity of leukemia. Few studies regarding mitochondrial aberrations and haplogroups in acute myeloid leukemia (AML) and their clinical impacts have been reported. Therefore, we focused on the mtDNA length heteroplasmies minisatellite instability (MSI), copy number alterations, and distribution of mitochondrial haplogroups in Korean patients with AML. Methods This study investigated 74 adult patients with AML and 70 controls to evaluate mtDNA sequence alterations, MSI, mtDNA copy number, haplogroups, and their clinical implications. The hypervariable (HV) control regions (HV1 and HV2), tRNAleu1gene, and cytochrome b gene of mtDNA were analyzed. Two mtDNA minisatellite markers, 16189 poly-C (16184CCCCCTCCCC16193, 5CT4C) and 303 poly-C (303CCCCCCCTCCCCC315, 7CT5C), were used to examine the mtDNA MSI. Results In AML, most mtDNA sequence variants were single nucleotide substitutions, but there were no significant differences compared to those in controls. The number of mtMSI patterns increased in AML. The mean mtDNA copy number of AML patients increased approximately 9-fold compared to that of controls (P<0.0001). Haplogroup D4 was found in AML with a higher frequency compared to that in controls (31.0% vs. 15.7%, P=0.046). None of the aforementioned factors showed significant impacts on the outcomes. Conclusion AML cells disclosed more heterogeneous patterns with the mtMSI markers and had increased mtDNA copy numbers. These findings implicate mitochondrial genome instability in primary AML cells. Therefore, mtDNA haplogroup D4 might be associated with AML risk among Koreans.
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Affiliation(s)
- Hye Ran Kim
- College of Korean Medicine, Dongshin University, Naju, Korea
| | - Min-Gu Kang
- Department of Laboratory Medicine, Gwangyang Sarang General Hospital, Gwangyang, Korea
| | - Young Eun Lee
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.,Brain Korea 21 Plus Project, Chonnam National University Medical School, Gwangju, Korea
| | - Bo Ram Na
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.,Brain Korea 21 Plus Project, Chonnam National University Medical School, Gwangju, Korea
| | - Min Seo Noh
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.,Brain Korea 21 Plus Project, Chonnam National University Medical School, Gwangju, Korea
| | - Seung Hyun Yang
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.,Brain Korea 21 Plus Project, Chonnam National University Medical School, Gwangju, Korea
| | - Jong-Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea
| | - Myun-Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea.,Brain Korea 21 Plus Project, Chonnam National University Medical School, Gwangju, Korea.,Environmental Health Center for Childhood Leukemia and Cancer, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea
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Cui X, Wang JY, Liu K, Cui SY, Zhang J, Luo YQ, Wang X. Role of heteroplasmic mutations in the mitochondrial genome and the ID4 gene promoter methylation region in the pathogenesis of chronic aplastic anemia in patients suffering from Kidney yin deficiency. Chin J Integr Med 2015; 22:412-9. [PMID: 25920536 DOI: 10.1007/s11655-014-1813-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To analyze changes in gene amplification in the mitochondrial genome and in the ID4 gene promoter methylation region in patients with chronic aplastic anemia (CAA) suffering from Kidney (Shen) yin deficiency or Kidney yang deficiency. METHODS Bone marrow and oral epithelium samples were collected from CAA patients with Kidney yin deficiency or Kidney yang deficiency (20 cases). Bone marrow samples were collected from 20 healthy volunteers. The mitochondrial genome was amplified by polymerase chain reaction (PCR), and PCR products were used for sequencing and analysis. RESULTS Higher mutational rates were observed in the ND1-2, ND4-6, and CYTB genes in CAA patients suffering from Kidney yin deficiency. Moreover, the ID4 gene was unmethylated in bone marrow samples from healthy individuals, but was methylated in some CAA patients suffering from Kidney yin deficiency (positive rate, 60%) and Kidney yang deficiency (positive rate, 55%). CONCLUSIONS These data supported that gene mutations can alter the expression of respiratory chain enzyme complexes in CAA patients, resulting in energy metabolism impairment and promoting the physiological and pathological processes of hematopoietic failure. Functional impairment of the mitochondrial respiration chain induced by gene mutation may be an important reason for hematopoietic failure in patients with CAA. This change is closely related to maternal inheritance and Kidney yin deficiency. Finally, these data supported the assertion that it is easy to treat disease in patients suffering from yang deficiency and difficult to treat disease in patients suffering from yin deficiency.
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Affiliation(s)
- Xing Cui
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China. .,Postdoctoral Research Station, Shandong University, Jinan, 250012, China.
| | - Jing-Yi Wang
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China
| | - Kui Liu
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China
| | - Si-Yuan Cui
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China
| | - Jie Zhang
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China
| | - Ya-Qin Luo
- Department of Hematology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250011, China
| | - Xin Wang
- Department of Hematology, Shangdong Province Hospital of Shandong University, Jinan, 250021, China
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3
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Won EJ, Kim HR, Park RY, Choi SY, Shin JH, Suh SP, Ryang DW, Szardenings M, Shin MG. Direct confirmation of quiescence of CD34+CD38- leukemia stem cell populations using single cell culture, their molecular signature and clinicopathological implications. BMC Cancer 2015; 15:217. [PMID: 25881148 PMCID: PMC4391681 DOI: 10.1186/s12885-015-1233-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/20/2015] [Indexed: 02/07/2023] Open
Abstract
Background The proliferating activity of a single leukemia stem cell and the molecular mechanisms for their quiescent property remain unknown, and also their prognostic value remains a matter of debate. Therefore, this study aimed to demonstrate the quiescence property and molecular signature of leukemia stem cell and their clinicopathological implications. Methods Single cell sorting and culture were performed in the various sets of hematopoietic stem cells including CD34+CD38- acute myeloid leukemia (AML) cell population (ASCs) from a total of 60 patients with AML, and 11 healthy controls. Their quiescence related-molecular signatures and clinicopathological parameters were evaluated in AML patients. Results Single cell plating efficiency of ASCs was significantly lower (8.6%) than those of normal hematopoietic stem cells i.e.: cord blood, 79.0%; peripheral blood, 45.3%; and bone marrow stem cell, 31.1%. Members of the TGFβ super-family signaling pathway were most significantly decreased; as well as members of the Wnt, Notch, pluripotency maintenance and hedgehog pathways, compared with non ASC populations. mtDNA copy number of ASCs was significantly lower than that of corresponding other cell populations. However, our data couldn’t support the prognostic value of the ASCs in AML. Conclusions ASCs showed remarkable lower plating efficiency and slower dividing properties at the single cell level. This quiescence is represented as a marked decrease in the mtDNA copy number and also linked with down-regulation of genes in various molecular pathways. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1233-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eun Jeong Won
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea.
| | - Hye-Ran Kim
- College of Korean Medicine, Dongshin University, Naju, South Korea.
| | - Ra-Young Park
- Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, South Korea.
| | - Seok-Yong Choi
- Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, South Korea.
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea.
| | - Soon-Pal Suh
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea.
| | - Dong-Wook Ryang
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea.
| | - Michael Szardenings
- Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany.
| | - Myung-Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea. .,Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, South Korea. .,Environment Health Center for Childhood Leukemia and Cancer, Chonnam National University Hwasun Hospital, Hwasun, South Korea.
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4
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Kim HR, Won SJ, Fabian C, Kang MG, Szardenings M, Shin MG. Mitochondrial DNA aberrations and pathophysiological implications in hematopoietic diseases, chronic inflammatory diseases, and cancers. Ann Lab Med 2014; 35:1-14. [PMID: 25553274 PMCID: PMC4272938 DOI: 10.3343/alm.2015.35.1.1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/07/2014] [Accepted: 11/11/2014] [Indexed: 12/25/2022] Open
Abstract
Mitochondria are important intracellular organelles that produce energy for cellular development, differentiation, and growth. Mitochondrial DNA (mtDNA) presents a 10- to 20-fold higher susceptibility to genetic mutations owing to the lack of introns and histone proteins. The mtDNA repair system is relatively inefficient, rendering it vulnerable to reactive oxygen species (ROS) produced during ATP synthesis within the mitochondria, which can then target the mtDNA. Under conditions of chronic inflammation and excess stress, increased ROS production can overwhelm the antioxidant system, resulting in mtDNA damage. This paper reviews recent literature describing the pathophysiological implications of oxidative stress, mitochondrial dysfunction, and mitochondrial genome aberrations in aging hematopoietic stem cells, bone marrow failure syndromes, hematological malignancies, solid organ cancers, chronic inflammatory diseases, and other diseases caused by exposure to environmental hazards.
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Affiliation(s)
- Hye-Ran Kim
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea. ; Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, Korea
| | - Stephanie Jane Won
- Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Claire Fabian
- Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - Min-Gu Kang
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea. ; Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, Korea
| | - Michael Szardenings
- Department of Cell Therapy, Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - Myung-Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea. ; Brain Korea 21 Project, Center for Biomedical Human Resources, Chonnam National University, Gwangju, Korea. ; Environment Health Center for Childhood Leukemia and Cancer, Chonnam National University Hwasun Hospital, Hwasun, Korea
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CUI XING, WANG JUNQIANG, CAI ZHIGUO, WANG JINGYI, LIU KUI, CUI SIYUAN, ZHANG JIE, LUO YAQIN, WANG XIN, LI WEIWEI, JING JINGYAN. Complete sequence analysis of mitochondrial DNA and telomere length in aplastic anemia. Int J Mol Med 2014; 34:1309-14. [DOI: 10.3892/ijmm.2014.1898] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 08/06/2014] [Indexed: 11/06/2022] Open
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Steele SL, Prykhozhij SV, Berman JN. Zebrafish as a model system for mitochondrial biology and diseases. Transl Res 2014; 163:79-98. [PMID: 24055494 DOI: 10.1016/j.trsl.2013.08.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/21/2013] [Accepted: 08/25/2013] [Indexed: 12/19/2022]
Abstract
Animal models for studying human disease are essential to the continuing evolution of medicine. Rodent models are attractive for the obvious similarities in development and genetic makeup compared with humans, but have cost and technical limitations. The zebrafish (Danio rerio) represents an ideal alternative vertebrate model of human disease because of its high conservation of genetic information and physiological processes, inexpensive maintenance, and optical clarity facilitating direct observation. This review highlights recent advances in understanding genetic disease states associated with the dynamic organelle, the mitochondrion, using the zebrafish. Mitochondrial diseases that have been replicated in the zebrafish include those affecting the nervous and cardiovascular systems, as well as red blood cell function. Gene silencing techniques, including morpholino knockdown and transcription activator-like (TAL)-effector endonucleases, have been exploited to demonstrate how loss of function can induce human disease-like states in zebrafish. Moreover, modeling mitochondrial diseases has been facilitated greatly by the creation of transgenic fish with fluorescently labeled mitochondria for in vivo visualization of these structures. In addition, behavioral assays have been developed to examine changes in motor activity and sensory responses, particularly in larval stages. Zebrafish are poised to advance our understanding of the pathogenesis of human mitochondrial diseases beyond the current state of knowledge and provide a key tool in the development of novel therapeutic approaches to treat these conditions.
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Affiliation(s)
- Shelby L Steele
- Department of Pediatrics, Dalhousie University, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Sergey V Prykhozhij
- Department of Pediatrics, Dalhousie University, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Jason N Berman
- Department of Pediatrics, Dalhousie University, IWK Health Centre, Halifax, Nova Scotia, Canada.
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7
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Bandelt HJ, Kloss-Brandstätter A, Richards MB, Yao YG, Logan I. The case for the continuing use of the revised Cambridge Reference Sequence (rCRS) and the standardization of notation in human mitochondrial DNA studies. J Hum Genet 2013; 59:66-77. [PMID: 24304692 DOI: 10.1038/jhg.2013.120] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 09/29/2013] [Accepted: 10/25/2013] [Indexed: 02/06/2023]
Abstract
Since the determination in 1981 of the sequence of the human mitochondrial DNA (mtDNA) genome, the Cambridge Reference Sequence (CRS), has been used as the reference sequence to annotate mtDNA in molecular anthropology, forensic science and medical genetics. The CRS was eventually upgraded to the revised version (rCRS) in 1999. This reference sequence is a convenient device for recording mtDNA variation, although it has often been misunderstood as a wild-type (WT) or consensus sequence by medical geneticists. Recently, there has been a proposal to replace the rCRS with the so-called Reconstructed Sapiens Reference Sequence (RSRS). Even if it had been estimated accurately, the RSRS would be a cumbersome substitute for the rCRS, as the new proposal fuses--and thus confuses--the two distinct concepts of ancestral lineage and reference point for human mtDNA. Instead, we prefer to maintain the rCRS and to report mtDNA profiles by employing the hitherto predominant circumfix style. Tree diagrams could display mutations by using either the profile notation (in conventional short forms where appropriate) or in a root-upwards way with two suffixes indicating ancestral and derived nucleotides. This would guard against misunderstandings about reporting mtDNA variation. It is therefore neither necessary nor sensible to change the present reference sequence, the rCRS, in any way. The proposed switch to RSRS would inevitably lead to notational chaos, mistakes and misinterpretations.
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Affiliation(s)
| | - Anita Kloss-Brandstätter
- Division of Genetic Epidemiology, Department of Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - Martin B Richards
- School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield, UK
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
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Cherian S, Bagg A. The genetics of the myelodysplastic syndromes: Classical cytogenetics and recent molecular insights. Hematology 2013; 11:1-13. [PMID: 16522543 DOI: 10.1080/10245330500276691] [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] [Indexed: 01/07/2023] Open
Abstract
Myelodysplastic syndromes (MDS) are a complex group of clonal hematopoietic disorders with an attendant diverse array of associated genetic changes. Conventional cytogenetics plays a prominent and well-established role in determining the contemporary diagnosis and prognosis of these disorders. More recently, molecular approaches have been useful in further characterizing this group of diseases, albeit in a largely experimental context, with the detection of changes at the single gene level including mutations, amplification and epigenetic phenomena. Nevertheless, we remain largely ignorant of the genetic underpinnings of MDS. Here we briefly review the established role of cytogenetics in MDS, and emphasize recent advances in unraveling the genetics of MDS, with a view towards how such findings might facilitate our ability to understand, diagnose and treat these disorders in a more rational manner.
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Affiliation(s)
- Sindhu Cherian
- University of Washington Medical Center, Department of Laboratory Medicine, Seattle, 98195, USA.
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Abstract
Refractory anemia with ring sideroblasts (RARS) is a subtype of myelodysplastic syndrome (MDS) characterized by 15% or more ring sideroblasts in the bone marrow according to the WHO classification. After Perls staining, ring sideroblasts are defined as erythroblasts in which there are 5 or more siderotic granules covering at least a third of the nuclear circumference. The iron deposited in perinuclear mitochondria of ring sideroblasts is present in the form of mitochondrial ferritin. The molecular basis of MDS with ring sideroblasts has remained unknown until recently. In 2011, whole exome sequencing studies revealed somatic mutations of SF3B1, a gene encoding a core component of RNA splicing machinery, in myelodysplasia with ring sideroblasts. The close relationship between SF3B1 mutation and ring sideroblasts is consistent with a causal relationship, and makes SF3B1 the first gene to be associated with a specific morphological feature in MDS. RARS is mainly characterized by isolated anemia due to ineffective erythropoiesis, and its clinical course is generally benign, although there is a tendency to worsening of anemia in most patients over time. By contrast, refractory cytopenia with multilineage dysplasia and ring sideroblasts (RCMD-RS) is characterized by pancytopenia and dysplasia in two or more myeloid cell lineages. More importantly, patients with RCMD-RS have a higher risk of developing bone marrow failure or progressing to acute myeloid leukemia (AML). Refractory anemia with ring sideroblasts (RARS-T) associated with marked thrombocytosis is a myelodysplastic/myeloproliferative neoplasm associated with both SF3B1 and JAK2 or MPL mutations. RARS-T may develop from an SF3B1 mutated RARS through the acquisition of a JAK2 or MPL mutations in a subclone of hematopoietic cells.
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Affiliation(s)
- Luca Malcovati
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Division of Hematology, Department of Hematology Oncology, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Mario Cazzola
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Division of Hematology, Department of Hematology Oncology, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy.
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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.
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Mitochondrial DNA variations in myelodysplastic syndrome. Ann Hematol 2013; 92:871-6. [DOI: 10.1007/s00277-013-1706-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 02/11/2013] [Indexed: 12/13/2022]
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Cui X, Liu F, Wang J, Zhang W, Wang J, Liu K, Cui S, Zhang J, Xu R. Complete sequence analysis of mitochondrial DNA of aplastic anemia patients. GENETICS AND MOLECULAR RESEARCH 2012; 11:2130-7. [DOI: 10.4238/2012.august.6.16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Eom HY, Kim HR, Kim HY, Han DK, Baek HJ, Lee JH, Moon JD, Shin JH, Suh SP, Ryang DW, Kook H, Shin MG. Mitochondrial DNA copy number and hnRNP A2/B1 protein: biomarkers for direct exposure of benzene. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:2762-2770. [PMID: 21919041 DOI: 10.1002/etc.675] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/14/2011] [Accepted: 08/09/2011] [Indexed: 05/31/2023]
Abstract
The present study was performed to identify biomarkers for exposure of benzene in blood cells and hematopoietic tissues. Peripheral mononuclear cells, hematopoietic stem cells, and leukemia cell lines were cultured in RPMI 1640 media with the addition of 0, 1, and 10 mM of benzene. Hydrogen peroxide was measured using an enzyme immunoassay. Mitochondrial mass, membrane potential, and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green/Red probes, and real-time polymerase chain reaction. In addition, two-dimensional gel electrophoresis and mass spectrometry matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology were performed to identify protein markers. The mitochondrial contents and membrane potentials were dramatically increased after three weeks of direct benzene exposure. The hydrogen peroxide level increased significantly after two weeks of treatment with benzene (4.4 ± 1.9 µM/mg protein) compared to the non-benzene treatment group (1.2 ± 1.0; p = 0.001). The mtDNA copy number gradually increased after exposure to benzene. Numerous protein markers showed significant aberrant expression after exposure to benzene. Among them, the heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 was markedly decreased after exposure to benzene. Thus, increased mitochondrial mass, mtDNA copy number, and the hnRNP A2/B1 protein were biomarkers for benzene-related toxicity and hematotoxicity.
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Affiliation(s)
- Ha-Young Eom
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, Korea
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Watson AS, Mortensen M, Simon AK. Autophagy in the pathogenesis of myelodysplastic syndrome and acute myeloid leukemia. Cell Cycle 2011; 10:1719-25. [PMID: 21512311 DOI: 10.4161/cc.10.11.15673] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autophagy is a conserved cellular pathway responsible for the sequestration of spent organelles and protein aggregates from the cytoplasm and their delivery into lysosomes for degradation. Autophagy plays an important role in adaptation to starvation, in cell survival, immunity, development and cancer. Recent evidence in mice suggests that autophagic defects in hematopoietic stem cells (HSCs) may be implicated in leukemia. Indeed, mice lacking Atg7 in HSCs develop an atypical myeloproliferation resembling human myelodysplastic syndrome (MDS) progressing to acute myeloid leukemia (AML). Studies suggest that accumulation of damaged mitochondria and reactive oxygen species result in cell death of the majority of progenitor cells and, possibly, concomitant transformation of some surviving ones. Interestingly, bone marrow cells from MDS patients are characterized by mitochondrial abnormalities and increased cell death. A role for autophagy in the transformation to cancer has been proposed in other cancer types. This review focuses on autophagy in human MDS development and progression to AML within the context of the role of mitochondria, apoptosis and reactive oxygen species (ROS) in its pathogenesis.
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NSMAP: a method for spliced isoforms identification and quantification from RNA-Seq. BMC Bioinformatics 2011; 12:162. [PMID: 21575225 PMCID: PMC3113944 DOI: 10.1186/1471-2105-12-162] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 05/16/2011] [Indexed: 11/26/2022] Open
Abstract
Background The development of techniques for sequencing the messenger RNA (RNA-Seq) enables it to study the biological mechanisms such as alternative splicing and gene expression regulation more deeply and accurately. Most existing methods employ RNA-Seq to quantify the expression levels of already annotated isoforms from the reference genome. However, the current reference genome is very incomplete due to the complexity of the transcriptome which hiders the comprehensive investigation of transcriptome using RNA-Seq. Novel study on isoform inference and estimation purely from RNA-Seq without annotation information is desirable. Results A Nonnegativity and Sparsity constrained Maximum APosteriori (NSMAP) model has been proposed to estimate the expression levels of isoforms from RNA-Seq data without the annotation information. In contrast to previous methods, NSMAP performs identification of the structures of expressed isoforms and estimation of the expression levels of those expressed isoforms simultaneously, which enables better identification of isoforms. In the simulations parameterized by two real RNA-Seq data sets, more than 77% expressed isoforms are correctly identified and quantified. Then, we apply NSMAP on two RNA-Seq data sets of myelodysplastic syndromes (MDS) samples and one normal sample in order to identify differentially expressed known and novel isoforms in MDS disease. Conclusions NSMAP provides a good strategy to identify and quantify novel isoforms without the knowledge of annotated reference genome which can further realize the potential of RNA-Seq technique in transcriptome analysis. NSMAP package is freely available at https://sites.google.com/site/nsmapforrnaseq.
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Bandelt HJ, Salas A. Current next generation sequencing technology may not meet forensic standards. Forensic Sci Int Genet 2011; 6:143-5. [PMID: 21565569 DOI: 10.1016/j.fsigen.2011.04.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 01/16/2011] [Accepted: 04/02/2011] [Indexed: 11/19/2022]
Abstract
In a Nature paper of 2010, the concern was raised that intra-individual mtDNA variation may be more pronounced than previously believed, in that heteroplasmies are common and vary markedly from tissue to tissue. This claim taken at face value would have considerable impact on forensic casework. It turns out however that the employed technology detected the germ-line variation relative to the reference sequence only incompletely: on average at least five mutations were missed per sample, as an in silico reassessment of the data reveals. Before one can really set out to access to entire mtDNA genome data with relative ease for forensic purposes, one needs careful calibration studies under strict forensic conditions-or might have to wait for another generation.
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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.
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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:
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Abstract
Three general approaches have been used to model myelodysplastic syndrome (MDS) in mice, including treatment with mutagens or carcinogens, xenotransplantation of human MDS cells, and genetic engineering of mouse hematopoietic cells. This article discusses the phenotypes observed in available mouse models for MDS with a concentration on a model that leads to aberrant expression of conserved homeobox genes that are important regulators of normal hematopoiesis. Using these models of MDS should allow a more complete understanding of the disease process and provide a platform for preclinical testing of therapeutic approaches.
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Affiliation(s)
- Sarah H Beachy
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 8901 Wisconsin Avenue, Bethesda, MD 20889-5105, USA
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Abstract
The pathogenesis of myelodysplastic syndromes involves a pattern of genetic, epigenetic, and immune-mediated mechanisms but little is known about what causes the specific disease features and promotes disease progression in the individual patient. The identification of JAK2 and MPL mutations, and more recently TET2, CBL and ASXL-1 mutations in these disorders provide a basis for increased understanding of disease biology and mechanisms behind progression. Such mutations are more commonly found in patients with a significant amount of marrow ring sideroblasts, and in patients belonging to the category of mixed myelodysplastic/myeloproliferative neoplasms, entities which are in focus for this review.
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Affiliation(s)
- Eva Hellström-Lindberg
- Karolinska Institutet, Department of Medicine, Division of Hematology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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20
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Cerezo M, Bandelt HJ, Martín-Guerrero I, Ardanaz M, Vega A, Carracedo Á, García-Orad Á, Salas A. High mitochondrial DNA stability in B-cell chronic lymphocytic leukemia. PLoS One 2009; 4:e7902. [PMID: 19924307 PMCID: PMC2775629 DOI: 10.1371/journal.pone.0007902] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 10/20/2009] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Chronic Lymphocytic Leukemia (CLL) leads to progressive accumulation of lymphocytes in the blood, bone marrow, and lymphatic tissues. Previous findings have suggested that the mtDNA could play an important role in CLL. METHODOLOGY/PRINCIPAL FINDINGS The mitochondrial DNA (mtDNA) control-region was analyzed in lymphocyte cell DNA extracts and compared with their granulocyte counterpart extract of 146 patients suffering from B-Cell CLL; B-CLL (all recruited from the Basque country). Major efforts were undertaken to rule out methodological artefacts that would render a high false positive rate for mtDNA instabilities and thus lead to erroneous interpretation of sequence instabilities. Only twenty instabilities were finally confirmed, most of them affecting the homopolymeric stretch located in the second hypervariable segment (HVS-II) around position 310, which is well known to constitute an extreme mutational hotspot of length polymorphism, as these mutations are frequently observed in the general human population. A critical revision of the findings in previous studies indicates a lack of proper methodological standards, which eventually led to an overinterpretation of the role of the mtDNA in CLL tumorigenesis. CONCLUSIONS/SIGNIFICANCE Our results suggest that mtDNA instability is not the primary causal factor in B-CLL. A secondary role of mtDNA mutations cannot be fully ruled out under the hypothesis that the progressive accumulation of mtDNA instabilities could finally contribute to the tumoral process. Recommendations are given that would help to minimize erroneous interpretation of sequencing results in mtDNA studies in tumorigenesis.
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MESH Headings
- Base Sequence
- DNA Primers/genetics
- DNA, Mitochondrial/genetics
- Databases, Genetic
- Granulocytes/cytology
- Haplotypes
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Lymphocytes/cytology
- Models, Statistical
- Molecular Sequence Data
- Mutation
- Phylogeny
- Sequence Analysis, DNA
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Affiliation(s)
- María Cerezo
- Unidade de Xenética, Instituto de Medicina Legal, and Departamento de Anatomía Patolóxica y Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | | | - Idoia Martín-Guerrero
- Laboratorio Interdepartamental de Medicina Molecular, Departamento de Genética Antropología Física y Fisiología Animal, Facultad de Medicina, Universidad del País Vasco- Euskal Herriko Unibertsitatea, Leioa, Spain
| | - Maite Ardanaz
- Servicio de Hematología, Hospital Txagorritxu, Vitoria, Spain
| | - Ana Vega
- Fundación Pública Galega de Medicina Xenómica (FPGMX), Hospital Clínico Universitario, Universidad de Santiago de Compostela, Galicia, Spain
| | - Ángel Carracedo
- Unidade de Xenética, Instituto de Medicina Legal, and Departamento de Anatomía Patolóxica y Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
| | - África García-Orad
- Laboratorio Interdepartamental de Medicina Molecular, Departamento de Genética Antropología Física y Fisiología Animal, Facultad de Medicina, Universidad del País Vasco- Euskal Herriko Unibertsitatea, Leioa, Spain
| | - Antonio Salas
- Unidade de Xenética, Instituto de Medicina Legal, and Departamento de Anatomía Patolóxica y Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain
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21
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Erythroid dysplasia, megaloblastic anemia, and impaired lymphopoiesis arising from mitochondrial dysfunction. Blood 2009; 114:4045-53. [PMID: 19734452 DOI: 10.1182/blood-2008-08-169474] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent reports describe hematopoietic abnormalities in mice with targeted instability of the mitochondrial genome. However, these abnormalities have not been fully described. We demonstrate that mutant animals develop an age-dependent, macrocytic anemia with abnormal erythroid maturation and megaloblastic changes, as well as profound defects in lymphopoiesis. Mice die of severe fatal anemia at 15 months of age. Bone-marrow transplantation studies demonstrate that these abnormalities are intrinsic to the hematopoietic compartment and dependent upon the age of donor hematopoietic stem cells. These abnormalities are phenotypically similar to those found in patients with refractory anemia, suggesting that, in some cases, the myelodysplastic syndromes are caused by abnormalities of mitochondrial function.
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22
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Malcovati L. Red Bood Cell Transfusion Therapy and Iron Chelation in Patients With Myelodysplastic Syndromes. ACTA ACUST UNITED AC 2009; 9 Suppl 3:S305-11. [DOI: 10.3816/clm.2009.s.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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23
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Valent P, Wieser R. Update on genetic and molecular markers associated with myelodysplastic syndromes. Leuk Lymphoma 2009; 50:341-8. [PMID: 19263296 DOI: 10.1080/10428190902756107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms defined by morphologic dysplasia, peripheral cytopenia and clonal instability with enhanced risk of transformation into acute myeloid leukemia. The prognosis and clinical picture in MDS vary depending on patient-related factors (age, gender, comorbidity), the disease variant, cell types affected and genes involved in the malignant process. In fact, more and more data suggest that cytogenetic and molecular defects and gene variants are associated with the clinical course and prognosis in MDS. Although certain molecular defects are indicative of distinct cytogenetic abnormalities, others represent point mutations in critical target genes (RUNX1, N-RAS, JAK2, KIT, others) and sometimes are associated with a particular type of MDS, an overlap disease, a co-existing hematopoietic neoplasm or disease progression. Although most are somatic mutations, germ line mutations and gene polymorphisms have also been described in MDS. Some of these mutations may influence the natural course of disease, iron accumulation or disease progression. The present article provides a summary of our current knowledge about molecular and genetic markers in MDS, with special reference to their potential prognostic and therapeutic implications.
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Affiliation(s)
- Peter Valent
- Division of Hematology and Hemostaseology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria.
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24
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Abstract
Session 4 of the 2007 Workshop of the Society for Hematopathology/European Association for Haematopathology was devoted to myelodysplastic syndromes (MDSs). Submitted cases highlighted important issues and difficulties in relation to the diagnosis and classification of MDS. Much of the discussion focused on the correlation, or lack of it, between morphologic examination and other diagnostic techniques, cytogenetics in particular. The cases included examples of isolated del(5q) chromosomal abnormality, including the "classical" 5q- syndrome and other myeloid neoplasms. Other cytogenetic abnormalities in MDSs and the role of cytogenetics in diagnosing MDSs were addressed. Particularly challenging is the correct identification of fibrotic subtypes of MDSs and their separation from subsets of acute myeloid leukemia with myelofibrosis such as acute panmyelosis with myelofibrosis. The association and eventual relation of MDSs (hypoplastic in particular) with aplastic anemia, paroxysmal nocturnal hemoglobinuria, and other nonneoplastic disorders were illustrated. Novel cytogenetic and molecular genetic approaches are likely to revolutionize the classification of MDSs. However, it is unlikely that these new techniques will be capable, on their own, of adequately stratifying patients for treatment purposes. At least for the foreseeable future, the diagnosis of MDS requires integration of morphologic, immunophenotypic, and genetic features in the light of patient history and clinical manifestations.
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25
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Pfeilstöcker M, Karlic H, Nösslinger T, Sperr W, Stauder R, Krieger O, Valent P. Myelodysplastic syndromes, aging, and age: Correlations, common mechanisms, and clinical implications. Leuk Lymphoma 2009; 48:1900-9. [DOI: 10.1080/10428190701534382] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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26
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Park SY, Shin MG, Kim HR, Oh JY, Kim SH, Shin JH, Cho YB, Suh SP, Ryang DW. Alteration of mitochondrial DNA sequence and copy number in nasal polyp tissue. Mitochondrion 2009; 9:318-25. [PMID: 19426839 DOI: 10.1016/j.mito.2009.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 04/02/2009] [Accepted: 04/29/2009] [Indexed: 11/19/2022]
Abstract
This study was designed to investigate the possibility that mtDNA mutations might arise in inflammatory or chronically damaged nasal polyp tissue from 23 patients. Thirteen patients (57%) displayed nasal polyp tissue-specific mtDNA mutations in the hypervariable segment of the control region and cytochrome b gene, which were not found in the corresponding blood cells and/or adjacent normal tissue. Nasal polyp tissue-specific length heteroplasmic mutations were also detected in nucleotide position (np) 303-315 homopolymeric poly C track (39%), np 514-523 CA repeats (17%) and np 16184-16193 poly C track (30%). The average mtDNA copy number was about three times higher in nasal polyp tissue than in the corresponding peripheral blood cells and adjacent non-polyp tissues. The level of reactive oxygen species (ROS) was significantly higher in the nasal polyp tissues compared to those from the corresponding samples. High level of ROS in nasal polyp tissue may contribute to development of mtDNA mutations, which may play a crucial role in the vicious cycle of pathophysiology of nasal polyps.
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Affiliation(s)
- Sang-Young Park
- Department of Laboratory Medicine and Molecular Genetics, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, 160 Ilsimri, Hwasun-eup, Hwasun-gun, Jeollanam-do 519-809, South Korea
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27
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Ou JJ, Bagg A. Diagnostic challenges in the myelodysplastic syndromes: the current and future role of genetic and immunophenotypic studies. EXPERT OPINION ON MEDICAL DIAGNOSTICS 2009; 3:275-91. [PMID: 23488463 DOI: 10.1517/17530050902813947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Myelodysplastic syndromes (MDS) comprise a clinically and pathologically diverse collection of hematopoietic neoplasms, most commonly presenting with peripheral cytopenias typically in the context of bone marrow hypercellularity. Mechanistically, at least in the early phases of the disease, this apparently paradoxical picture is primarily due to ineffective hematopoiesis, which is accompanied by a variety of morphologic abnormalities in hematopoietic cells. The identification of recurrent, clinically relevant cytogenetic defects in MDS has spurred the research of molecular mechanisms that contribute to its inception as well as to the development of heterogeneous subtypes. Although conventional cytogenetic analyses remain a diagnostic mainstay in MDS, the application of contemporary techniques including molecular cytogenetics, microarray technologies and multiparametric flow cytometry may ultimately reveal new diagnostic parameters that are theoretically more objective and sensitive than current morphologic approaches. This review aims to outline the role of genetic and immunophenotypic studies in the evaluation of MDS, including findings that may potentially influence future diagnostic classifications, which could refine prognostication and ultimately facilitate the growth of targeted therapies.
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Affiliation(s)
- Joyce J Ou
- University of Pennsylvania, Department of Pathology and Laboratory Medicine, 3400 Spruce Street, 6 Founders Pavilion, PA 19406-4283, USA
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28
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Houwerzijl EJ, Pol HWD, Blom NR, van der Want JJL, de Wolf JTM, Vellenga E. Erythroid precursors from patients with low-risk myelodysplasia demonstrate ultrastructural features of enhanced autophagy of mitochondria. Leukemia 2009; 23:886-91. [PMID: 19148135 DOI: 10.1038/leu.2008.389] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 11/06/2008] [Accepted: 11/25/2008] [Indexed: 01/10/2023]
Abstract
Recent studies in erythroid cells have shown that autophagy is an important process for the physiological clearance of mitochondria during terminal differentiation. However, autophagy also plays an important role in removing damaged and dysfunctional mitochondria. Defective mitochondria and impaired erythroid maturation are important characteristics of low-risk myelodysplasia. In this study we therefore questioned whether the autophagic clearance of mitochondria might be altered in erythroblasts from patients with refractory anemia (RA, n=3) and RA with ringed sideroblasts (RARS, n=6). Ultrastructurally, abnormal and iron-laden mitochondria were abundant, especially in RARS patients. A large proportion (52+/-16%) of immature and mature myelodysplastic syndrome (MDS) erythroblasts contained cytoplasmic vacuoles, partly double membraned and positive for lysosomal marker LAMP-2 and mitochondrial markers, findings compatible with autophagic removal of dysfunctional mitochondria. In healthy controls only mature erythroblasts comprised these vacuoles (12+/-3%). These findings were confirmed morphometrically showing an increased vacuolar surface in MDS erythroblasts compared to controls (P<0.0001). In summary, these data indicate that MDS erythroblasts show features of enhanced autophagy at an earlier stage of erythroid differentiation than in normal controls. The enhanced autophagy might be a cell protective mechanism to remove defective iron-laden mitochondria.
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Affiliation(s)
- E J Houwerzijl
- Department of Hematology, University Medical Center Groningen, Groningen, The Netherlands.
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29
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Kim HR, Shin MG, Kim MJ, Kim HJ, Shin JH, Suh SP, Ryang DW. Mitochondrial DNA aberrations of bone marrow cells from patients with aplastic anemia. J Korean Med Sci 2008; 23:1062-7. [PMID: 19119453 PMCID: PMC2610644 DOI: 10.3346/jkms.2008.23.6.1062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 03/12/2008] [Indexed: 11/25/2022] Open
Abstract
This study was undertaken primarily to test the hypothesis that mitochondrial DNA (mtDNA) mutations may be associated with aplastic anemia. Complete mtDNA nucleotide sequence was analyzed in nine and eight bone marrow specimens from Korean patients with aplastic anemia and healthy individuals, respectively. We found a large number of polymorphisms as well as apparent new mutations in both patients and controls throughout the entire mtDNA genome; 12 mutations harbored amino acid changes in patients and none of the mutations in controls produced amino acid changes. There were heteroplasmic mutations and more nonsynonymous mtDNA changes observed in patients, so the mean number of mtDNA aberrations of bone marrow cells showed statistically significant difference overall between patients (mean=25.6) and controls (mean=12.8) (p=0.019). Our data may support an association of mtDNA aberrations with aplastic anemia.
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Affiliation(s)
- Hye-Ran Kim
- Genome Research Center for Hematopoietic Disease, Chonnam National University Medical School, Chonnam National University Hwasun Hospital, Hwasun, Korea
- Brain Korea 21 Project, Center for Biomedical Human Resources at Chonnam National University, Gwangju, Korea
| | - Myung-Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Korea
| | - Mi-Ji Kim
- Genome Research Center for Hematopoietic Disease, Chonnam National University Medical School, Chonnam National University Hwasun Hospital, Hwasun, Korea
| | - Hyeoung-Joon Kim
- Genome Research Center for Hematopoietic Disease, Chonnam National University Medical School, Chonnam National University Hwasun Hospital, Hwasun, Korea
| | - Jong-Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Korea
| | - Soon-Pal Suh
- Department of Laboratory Medicine, Chonnam National University Medical School, Korea
| | - Dong-Wook Ryang
- Department of Laboratory Medicine, Chonnam National University Medical School, Korea
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Wulfert M, Küpper AC, Tapprich C, Bottomley SS, Bowen D, Germing U, Haas R, Gattermann N. Analysis of mitochondrial DNA in 104 patients with myelodysplastic syndromes. Exp Hematol 2008; 36:577-86. [PMID: 18439489 DOI: 10.1016/j.exphem.2008.01.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 01/15/2008] [Accepted: 01/16/2008] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the frequency and spectrum of somatic mutations of mitochondrial DNA (mtDNA) in bone marrow of patients with myelodysplastic syndrome (MDS). MATERIALS AND METHODS Analysis included 104 patients with MDS (24 refractory anemia, 32 refractory anemia with ringed sideroblasts, 34 refractory anemia with excess of blasts, 7 refractory anemia with excess of blasts in transformation to acute leukemia, and 7 chronic myelo-monocytic leukemia), 3 patients with acute myeloid leukemia from MDS, and 36 patients with myeloproliferative disease (23 chronic myeloid leukemia, 9 polycythemia vera, 4 idiopathic myelofibrosis). Mutation scanning was performed using heteroduplex analysis with denaturing high-performance liquid chromatography (dHPLC). The entire mitochondrial genome was amplified in 67 overlapping polymerase chain reaction fragments carefully optimized regarding DNA melting profiles. Abnormal dHPLC findings were confirmed by DNA sequencing. RESULTS Heteroplasmic mtDNA mutations, mostly transitions, were identified in 56% of MDS and 44% of myeloproliferative disorders patients. In MDS, mutation frequency increased with age and more-advanced disease. Mutational spectra showed no hot spots and were similar in different types of MDS. Heteroplasmic mutations generally did not represent known polymorphisms, and about half of them affected conserved amino acids or nucleotides. Mutations were less frequent in protein encoding genes (50 per 10(6) base pairs) than other mitochondrial genes (transfer RNAs, ribosomal RNAs, and control region; about 80 per 10(6) base pairs). CONCLUSIONS As mitochondria often show ultrastructural abnormalities in MDS, including pathological iron accumulation, mitochondrial dysfunction may contribute to MDS pathology. We found a high frequency of acquired mtDNA mutations in MDS. However, their functional importance remains unclear, considering that genotype correlates poorly with phenotype in mitochondrial diseases. The clonally expanded mtDNA mutations in MDS support the concept of age-related damage to mtDNA in hematopoietic stem cells.
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Affiliation(s)
- Michael Wulfert
- Klinik für Hämatologie, Onkologie und Klinische Immunologie, Heinrich-Heine-Universität, Düsseldorf, Germany
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31
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Martin FM, Prchal J, Nieva J, Saven A, Andrey J, Bethel K, Barton JC, Aripally G, Bottomley SS, Friedman JS. Purification and characterization of sideroblasts from patients with acquired and hereditary sideroblastic anaemia. Br J Haematol 2008; 143:446-50. [PMID: 18729851 DOI: 10.1111/j.1365-2141.2008.07358.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nolte F, Hofmann WK. Myelodysplastic syndromes: molecular pathogenesis and genomic changes. Ann Hematol 2008; 87:777-95. [PMID: 18516602 DOI: 10.1007/s00277-008-0502-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Accepted: 04/15/2008] [Indexed: 01/27/2023]
Abstract
Myelodysplastic syndromes (MDS) are characterized by ineffective hematopoiesis presenting with peripheral cytopenias in combination with a hyperplastic bone marrow and an increased risk of evolution to acute myeloid leukemia. The classification systems such as the WHO classification mainly rely on morphological criteria and are supplemented by the International Prognostic Scoring System which takes cytogenetical changes into consideration when determining the prognosis of MDS but wide intra-subtype variations do exist. The pathomechanisms causing primary MDS require further work. Development and progression of MDS is suggested to be a multistep alteration to hematopoietic stem cells. Different molecular alterations have been described, affecting genes involved in cell-cycle control, mitotic checkpoints, and growth factor receptors. Secondary signal proteins and transcription factors, which gives the cell a growth advantage over its normal counterpart, may be affected as well. The accumulation of such defects may finally cause the leukemic transformation of MDS.
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Affiliation(s)
- Florian Nolte
- Department of Hematology and Oncology, University Hospital Benjamin Franklin, Charité, Hindenburgdamm 30, 12203, Berlin, Germany.
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33
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Invernizzi R, Travaglino E. Increased Apoptosis as a Mechanism of Ineffective Erythropoiesis in Myelodysplastic Syndromes. ACTA ACUST UNITED AC 2008. [DOI: 10.3816/clk.2008.n.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hellström-Lindberg E, Malcovati L. Supportive care and use of hematopoietic growth factors in myelodysplastic syndromes. Semin Hematol 2008; 45:14-22. [PMID: 18179965 DOI: 10.1053/j.seminhematol.2007.10.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Supportive care constitutes the basis of the management of patients with myelodysplastic syndromes (MDS). Appropriate treatment of cytopenia, as well as of other related complications, not only improves quality of life but also may positively affect the overall survival of patients. Anemia is the most common cytopenia in MDS, and the requirement for regular transfusions is a major clinical problem for patients with low-risk MDS. An important therapeutic goal in this patient group is to maintain acceptable hemoglobin levels without transfusions. Today, this goal can be achieved by treatment with erythropoietin (Epo) +/- granulocyte colony-stimulating factor (G-CSF), or by more targeted treatment such as antithymocyte globulin or lenalidomide in around 50% of patients. For the remaining patients, and for those who lose their therapeutic response, chronic transfusion therapy, with or without the addition of chelating agents, is the only option and it is important that this treatment is scheduled to meet the needs of the individual patient. Severe thrombocytopenia has recently been reported to respond to thrombopoietic agents, such as AMG 531.
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Affiliation(s)
- Eva Hellström-Lindberg
- Karolinska Institutet, Department of Medicine, Division of Hematology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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35
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36
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Hellström-Lindberg E, Cazzola M. The role of JAK2 mutations in RARS and other MDS. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2008; 2008:52-59. [PMID: 19074058 DOI: 10.1182/asheducation-2008.1.52] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Acquired sideroblastic anemia with unilineage dysplasia (WHO RARS) is a clonal stem cell disorder characterized by erythroid dysplasia, mitochondrial accumulation of mitochondrial ferritin, defective erythroid maturation and anemia. A fraction of these patients also show elevated platelet counts; since 2001 this has been defined as RARS with marked thrombocytosis (RARS-T). It has recently been described that around half of RARS-T patients, along with a small subset of other MDS and mixed myelodysplastic/ myeloproliferative disorders, carry the JAK2 mutation, and that MPL mutations are found in single patients. Clinically, RARS-T patients show features of both RARS, essential thrombocythmia (ET) and to some extent also myelofibrosis. However, the degree of anemia and overall survival is more similar to RARS than myeloproliferative disorders. The occurrence of JAK2 mutations and features of ET in RARS is too frequent to be the result of chance only, and it is possible that this link may provide a key to an increased understanding of the genetic abnormalities causing ring sideroblast formation.
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Affiliation(s)
- Eva Hellström-Lindberg
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.
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37
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Wang CY, Wang HW, Yao YG, Kong QP, Zhang YP. Somatic mutations of mitochondrial genome in early stage breast cancer. Int J Cancer 2007; 121:1253-6. [PMID: 17514652 DOI: 10.1002/ijc.22822] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The complete mitochondrial genomes of the primary cancerous, matched paracancerous normal and distant normal tissues from 10 early-stage breast cancer patients were analyzed in this study, with special attempt (i) to investigate whether the reported high frequency of mitochondrial DNA (mtDNA) somatic mutations in breast cancer could be repeated under a stringent data quality control, and (ii) to characterize the spectrum of mtDNA somatic mutations in Chinese breast cancer patients and evaluate their potential significance in early cancer diagnosis. Two heteroplasmic somatic transitions (T2275C and A8601G) were identified in our samples. The transition A8601G was present in the primary cancerous and paracancerous normal tissues from patient no. 3. Transition T2275C was found in the primary cancerous tissue but not in other normal tissues from patient no. 6; this transition has been reported in the colonic crypts and is located at a highly conserved site in the 16S rRNA gene. Subsequent cloning sequencing confirmed the absence of both mutations in the distant normal tissues from the 2 patients. The overall rate of somatic mutations in our patients was much lower than those of previous studies of breast cancer. Our results gave support to the recent claim that the high frequency of mtDNA somatic mutations in cancer studies is overestimated. Based on the mtDNA mutation pattern in early stage breast cancer observed in this study, we cautioned the enthusiasm and efforts to look for somatic mutations that were of diagnostic value in cancer early detection.
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Affiliation(s)
- Cheng-Ye Wang
- Laboratory of Cellular and Molecular Evolution, and Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
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38
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Sáfrány E, Csöngei V, Járomi L, Maász A, Magyari L, Sipeky C, Melegh B. Mitochondrial DNA and its mutations: novel fields in a new era. Orv Hetil 2007; 148:971-8. [PMID: 17513250 DOI: 10.1556/oh.2007.28014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Az utóbbi két évtizedet tartják a klinikai mitokondriális DNS-kutatás aranykorának. Folyamatosan bővül a patológiás variánsok száma, amelyek betegséggel társulnak, illetve bővül az ismeretanyag azokról az entitásokról, melyek hátterében a mitokondriális DNS kóros elváltozásai állnak. A cirkuláris mitokondriális DNS öröklődése eltér a Mendel-féle szabályoktól, anyai öröklésmenetet mutat; számos vonatkozásban eltérő sajátosságokkal rendelkezik a nukleáris DNS-hez viszonyítva. A molekuláris biológiai módszerek terjedésével egyre több kórkép ismerhető fel, noha a diagnosztika manapság is komoly kihívást jelent. Napjainkban a mitokondriális medicina számos orvosi szubspecialitáshoz kapcsolódóan jelentős előrelépéseket mutatott; így körvonalazódott a mitokondriális gasztroenterológia, endokrinológia, otológia, oftalmológia, nefrológia, hematológia, onkológia, reproduktív medicina és pszichiátria, mintegy az adott szubspecialitás mitokondriális DNS-sel kapcsolatos, többé-kevésbé részleges önállósodással megjelenő territóriuma. A jelen összefoglaló közlemény a mitokondriális medicina rövid, általános összefoglalása mellett e fejezetekre próbál rátekintést nyújtani.
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Affiliation(s)
- Eniko Sáfrány
- Pécsi Tudományegyetem, Altalános Orvostudományi Kar Orvosi Genetikai és Gyermekfejlodéstani Intézet, Pécs, Szigeti u. 12. 7624
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39
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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.
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Affiliation(s)
- David P Steensma
- Division of Hematology, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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40
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Thompson JE, Conlon JP, Yang X, Sanchez PV, Carroll M. Enhanced growth of myelodysplastic colonies in hypoxic conditions. Exp Hematol 2007; 35:21-31. [PMID: 17198870 PMCID: PMC3677695 DOI: 10.1016/j.exphem.2006.08.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/21/2006] [Accepted: 08/28/2006] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To determine the response of bone marrow progenitor cells from patients with myelodysplastic syndromes (MDS) to culture in physiologic oxygen tension. METHODS Methylcellulose progenitor assays using both unfractionated bone marrow mononuclear cells (MNCs) and purified CD34(+) progenitors were performed in atmospheric oxygen (18.6% O(2)) or one of two levels of hypoxia (1% and 3% O(2)). Assays were performed using normal donor marrow, MDS patient marrow, acute myelogenous leukemia marrow or peripheral blood blasts, chronic phase chronic myelogenous leukemia (CML) marrow MNCs, and blast crisis CML peripheral blood. RESULTS The majority of MDS samples showed decreased colony-forming units (CFU) in 18.6% O(2) compared to normal controls, as expected. However, in either 1% or 3% O(2), 9 of 13 MDS samples demonstrated augmentation of CFUs beyond that observed in normal controls, with 6 of 13 demonstrating a greater than ninefold augmentation. This effect is cell autonomous, as it persisted after purification of CD34(+) progenitor cells. Additionally, the augmented response to physiologic oxygen tension is specific to MDS, as it was not observed in either acute or chronic myelogenous leukemia samples. CONCLUSION These results suggest that the reported decrease in MDS CFUs reflects greater sensitivity of MDS progenitors or their progeny to the nonphysiologic oxygen tensions routinely used in vitro, rather than a true decrease in progenitor frequency. Importantly, these experiments for the first time describe an experimental system that can be used to study the growth of primary cells from patients with MDS.
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Affiliation(s)
- James Edwin Thompson
- Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA 19104-6160, USA.
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41
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Fontenay M, Cathelin S, Amiot M, Gyan E, Solary E. Mitochondria in hematopoiesis and hematological diseases. Oncogene 2006; 25:4757-67. [PMID: 16892088 DOI: 10.1038/sj.onc.1209606] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mitochondria are involved in hematopoietic cell homeostasis through multiple ways such as oxidative phosphorylation, various metabolic processes and the release of cytochrome c in the cytosol to trigger caspase activation and cell death. In erythroid cells, the mitochondrial steps in heme synthesis, iron (Fe) metabolism and Fe-sulfur (Fe-S) cluster biogenesis are of particular importance. Mutations in the specific delta-aminolevulinic acid synthase (ALAS) 2 isoform that catalyses the first and rate-limiting step in heme synthesis pathway in the mitochondrial matrix, lead to ineffective erythropoiesis that characterizes X-linked sideroblastic anemia (XLSA), the most common inherited sideroblastic anemia. Mutations in the adenosine triphosphate-binding cassette protein ABCB7, identified in XLSA with ataxia (XLSA-A), disrupt the maturation of cytosolic (Fe-S) clusters, leading to mitochondrial Fe accumulation. In addition, large deletions in mitochondrial DNA, whose integrity depends on a specific DNA polymerase, are the hallmark of Pearson's syndrome, a rare congenital disorder with sideroblastic anemia. In acquired myelodysplastic syndromes at early stage, exacerbation of physiological pathways involving caspases and the mitochondria in erythroid differentiation leads to abnormal activation of a mitochondria-mediated apoptotic cell death pathway. In contrast, oncogenesis-associated changes at the mitochondrial level can alter the apoptotic response of transformed hematopoietic cells to chemotherapeutic agents. Recent findings in mitochondria metabolism and functions open new perspectives in treating hematopoietic cell diseases, for example various compounds currently developed to trigger tumor cell death by directly targeting the mitochondria could prove efficient as either cytotoxic drugs or chemosensitizing agents in treating hematological malignancies.
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Affiliation(s)
- M Fontenay
- Inserm U567, Institut Cochin, Department of Hematology, Paris, Cedex, France
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42
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Matthes T, Rustin P, Trachsel H, Darbellay R, Costaridou S, Xaidara A, Rideau A, Beris P. Different pathophysiological mechanisms of intramitochondrial iron accumulation in acquired and congenital sideroblastic anemia caused by mitochondrial DNA deletion. Eur J Haematol 2006; 77:169-74. [PMID: 16856911 DOI: 10.1111/j.1600-0609.2006.00674.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Sideroblastic anemias (SA) are characterized by iron accumulation in the mitochondria of erythroblasts. Although we have evidence of mitochondrial gene alterations in sporadic congenital cases, the origin of acquired forms [refractory anemia with ring sideroblasts (RARS)], is still largely unknown. Here, we report the analysis of respiratory chain function in a patient with a large mitochondrial deletion and in patients with RARS. A young boy with SA showed symptoms typical of a mitochondrial disease with metabolic acidosis, muscle weakness and cerebral involvement. His bone marrow DNA was analyzed for the presence of mitochondrial deletions. We found a new mitochondrial (mt)DNA deletion spanning 3,614 bp and including all the mt genes encoding complex IV, plus ATPase 6 and 8, and several transfer (t)RNAs. All tissues analyzed (liver, skeletal muscle, brain, pancreas) showed a heteroplasmic distribution of this mutant DNA. Bone marrow homogenates were obtained from five patients with RARS and from three patients with normal bone marrow and respiratory chain function assayed by spectrophotometric analysis. Cytochrome c oxidase (CCO) activity was greatly reduced in the patient's bone marrow. In contrast, CCO activity and global respiratory chain function were conserved in patients with RARS. We conclude that deficient CCO activity secondary to mtDNA deletions is related to intramitochondrial iron accumulation, as in our patient or in those with Pearson's syndrome, whereas other mechanisms, e.g. nuclear DNA mutations, have to be proposed to be involved in the acquired forms of SA.
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Affiliation(s)
- Thomas Matthes
- Department of Internal Medicine, Unit of Clinical Hematology, University Hospital, Geneva, Switzerland.
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43
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Shin MG, Levin BC, Kim HJ, Kim HR, Lee IK, Cho D, Kee SJ, Shin JH, Suh SP, Ryang DW. Profiling of length heteroplasmies in the human mitochondrial DNA control regions from blood cells in the Korean population. Electrophoresis 2006; 27:1331-40. [PMID: 16502464 DOI: 10.1002/elps.200500551] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The length heteroplasmies in the hypervariable (HV) regions of mitochondrial DNA (mtDNA) from blood cells were examined in 57 healthy Korean donors. Interestingly, all the healthy Korean subjects displayed length heteroplasmies in both the HV1 and HV2 regions. Closer examination of the HV2 length heteroplasmies indicated that most of these donors (84%) exhibited a minimal 303-315 homopolymeric C (poly-C) tract frameshift of 1 bp (mixture of one major and minor mtDNA type). Sixteen percent of the donors however had poly-C tract frameshifts of 2 bp or more. The donor group with major length variants (two or more frameshifts) had about a two-fold decrease in mtDNA copy number compared with the group exhibiting only a 1 bp frameshift. This result supports the possibility that a severe frameshift in the 303-315 poly-C tract may also cause the impairment of mtDNA replication in hematopoietic tissue.
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Affiliation(s)
- Myung-Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School and Chonnam National University Hwasun Hospital, Hwasun, South Korea.
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44
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Tehranchi R. Impact of growth factors in the regulation of apoptosis in low-risk myelodysplastic syndromes. Med Oncol 2006; 23:37-49. [PMID: 16645228 DOI: 10.1385/mo:23:1:137] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Revised: 11/30/1999] [Accepted: 03/28/2005] [Indexed: 11/11/2022]
Abstract
Increased apoptosis of hematopoietic progenitors is a hallmark of myelodysplastic syndromes (MDS) and results in ineffective hematopoiesis. Erythroid apoptosis is thought to be the main mechanism underlying the severe anemia observed in the low-risk subgroups, refractory anemia (RA) and RA with ringed sideroblasts (RARS). Treatment with erythropoietin (Epo) alone or in combination with granulocyte colony-stimulating factor (G-CSF) may significantly improve anemia and reduce bone marrow apoptosis. A synergistic effect between Epo and G-CSF has been observed in the clinic, in particular in RARS. However, the molecular mechanisms beyond the anti-apoptotic effect of these growth factors have not been fully understood. This paper outlines the potential mechanisms underlying the augmented apoptosis during the erythroid differentiation in low-risk MDS as well as the anti-apoptotic effect of the growth factors.
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Affiliation(s)
- R Tehranchi
- Hematopoietic Stem Cell Laboratory, Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, SE-22184 Lund, Sweden.
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45
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Haimi M, Elhasid R, Gershoni-Baruch R, Izraeli S, Wanders RJA, Mandel H. Myeloid dysplasia in familial 3-methylglutaconic aciduria. J Pediatr Hematol Oncol 2006; 28:69-72. [PMID: 16462576 DOI: 10.1097/01.mph.0000199585.98926.55] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A kindred is reported with four members affected with neurodegenerative disorder and 3-methylglutaconic aciduria. Two siblings developed thrombocytopenia heralding a myelodysplastic syndrome; in one patient it evolved into acute myeloid leukemia with monosomy 7 in the marrow. The hematologic complications have hitherto not been previously reported in other cases of 3-methylglutaconic aciduria and are thus thought to represent a new disease entity. This family adds additional evidence to the genetic heterogeneity of Mendelian disorders in which the primary mutation may have a mutator effect that could give origin to myelodysplastic syndrome and acute myeloid leukemia through acquired chromosomal changes.
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Affiliation(s)
- Motti Haimi
- Department of Pediatric Hemato-Oncology, Meyer Children's Hospital, Rambam Medical Center, Haifa, Israel
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46
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Ogasawara Y, Nakayama K, Tarnowka M, McCoy JP, Kajigaya S, Levin BC, Young NS. Mitochondrial DNA spectra of single human CD34+ cells, T cells, B cells, and granulocytes. Blood 2005; 106:3271-84. [PMID: 16020515 PMCID: PMC1895318 DOI: 10.1182/blood-2005-01-0150] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, we described the age-dependent accumulation of mitochondrial DNA (mtDNA) mutations, leading to a high degree of mtDNA heterogeneity among normal marrow and blood CD34+ clones and in granulocytes. We established a method for sequence analysis of single cells. We show marked, distinct mtDNA heterogeneity from corresponding aggregate sequences in isolated cells of 5 healthy adult donors-37.9% +/- 3.6% heterogeneity in circulating CD34+ cells, 36.4% +/- 14.1% in T cells, 36.0% +/- 10.7% in B cells, and 47.7% +/- 7.4% in granulocytes. Most heterogeneity was caused by poly-C tract variability; however, base substitutions were also prevalent, as follows: 14.7% +/- 5.7% in CD34+ cells, 15.2% +/- 9.0% in T cells, 15.4% +/- 6.7% in B cells, and 32.3% +/- 2.4% in granulocytes. Many poly-C tract length differences and specific point mutations seen in these same donors but assayed 2 years earlier were still present in the new CD34+ samples. Additionally, specific poly-C tract differences and point mutations were frequently shared among cells of the lymphoid and myeloid lineages. Secular stability and lineage sharing of mtDNA sequence variability suggest that mutations arise in the lymphohematopoietic stem cell compartment and that these changes may be used as a natural genetic marker to estimate the number of active stem cells.
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Affiliation(s)
- Yoji Ogasawara
- Hematology Branch and Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bldg 10 CRC, 3E-5140, 9000 Rockville Pike, Bethesda, MD 20892-1202, USA
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47
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Steensma DP, List AF. Genetic testing in the myelodysplastic syndromes: molecular insights into hematologic diversity. Mayo Clin Proc 2005; 80:681-98. [PMID: 15887439 DOI: 10.4065/80.5.681] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The myelodysplastic syndromes (MDS) are associated with a diverse set of acquired somatic genetic abnormalities. Bone marrow karyotyping provides important diagnostic and prognostic information and should be attempted in all patients who are suspected of having MDS. Fluorescent in situ hybridization (FISH) studies on blood or marrow may also be valuable in selected cases, such as patients who may have 5q- syndrome or those who have undergone hematopoletic stem cell transplantation. The MDS-associated cytogenetic abnormalities that have been defined by karyotyping and FISH studies have already contributed substantially to our current understanding of the biology of malignant myeloid disorders, but the pathobiological meaning of common, recurrent chromosomal lesions such as del(5q), del(20q), and monosomy 7 is still unknown. The great diversity of the cytogenetic findings described in MDS highlights the molecular heterogeneity of this cluster of diseases. We review the common and pathophysiologically interesting genetic abnormalities associated with MDS, focusing on the clinical utility of conventional cytogenetic assays and selected FISH studies. In addition, we discuss a series of well-defined MDS-associated point mutations and outline the potential for further insights from newer techniques such as global gene expression profiling and array-based comparative genomic hybridization.
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Affiliation(s)
- David P Steensma
- Department of Internal Medicine and Division of Hematology, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA
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Craven SE, French D, Ye W, de Sauvage F, Rosenthal A. Loss of Hspa9b in zebrafish recapitulates the ineffective hematopoiesis of the myelodysplastic syndrome. Blood 2005; 105:3528-34. [PMID: 15650063 DOI: 10.1182/blood-2004-03-1089] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Myelodysplastic syndrome (MDS) comprises a heterogeneous group of often fatal hematopoietic stem cell disorders for which neither curative nor standard treatment exists. The complex karyotypes and multistep nature of MDS have severely restricted the identification of causative genetic mutations and thus limited insight into new and more effective therapies. Here we describe a zebrafish mutant crimsonless (crs) with a developmental blood defect that closely recapitulates the ineffective hematopoiesis of MDS including anemia, dysplasia, increased blood cell apoptosis, and multilineage cytopenia. By positional cloning, rescue, and morpholino knockdown experiments, we demonstrate that crs encodes a conserved mitochondrial matrix chaperone HSPA9B containing a glycine-to-glutamate substitution within the substrate-binding domain. This mutation compromises mitochondrial function, producing oxidative stress and apoptosis distinctly in blood cells. Thus, we identify an essential role for Hspa9b in hematopoiesis and implicate both loss of HSPA9B specifically and mitochondrial dysfunction generally in the pathogenesis of the MDS.
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Babusiaková E, Vyoral D, Neuwirtová R, Sisková M, Zeman J, Kmoch S. Accumulation of homoplasmic mtDNA point mutations in erythroblasts isolated from the bone marrow of patients with refractory anemia with ring sideroblasts (RARS). Mitochondrion 2004; 4:321-9. [PMID: 16120395 DOI: 10.1016/j.mito.2004.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 06/08/2004] [Accepted: 06/09/2004] [Indexed: 11/21/2022]
Abstract
It was hypothesised that mitochondrial iron overload in patients with refractory anemia with ring sideroblasts (RARS) results from mitochondrial DNA (mtDNA) mutations. To analyse the mtDNA sequence of iron storing mitochondria sensitively, we developed new protocols for selective erythroblasts isolation, mtDNA PCR amplification and sequencing. Using this approach, we found in each of the three RARS patients examined a unique spectrum of homoplasmic mtDNA point mutations affecting several mtDNA genes. Prediction analyses suggest that identified mutations do not result in major perturbations of mitochondrial functions and are tolerated. We discuss a mechanism explaining how the mutations identified may contribute to RARS pathogenesis.
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Affiliation(s)
- E Babusiaková
- Center of Integrated Genomics and Institute for Inherited Metabolic Disorders, 1st Faculty of Medicine, Charles University, Ke Karlovu 2, Praha 2 Prague 12808, Czech Republic.
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Abstract
Erythropoiesis is a complex multistep process encompassing the differentiation of hemopoietic stem cells to mature erythrocytes. The steps involved in this complex differentiation process are numerous and involve first the differentiation to early erythoid progenitors (burst-forming units-erythroid, BFU-E), then to late erythroid progenitors (colony-forming units-erythroid) and finally to morphologically recognizable erythroid precursors. A key event of late stages of erythropoiesis is nuclear condensation, followed by extrusion of the nucleus to produce enucleated reticulocytes and finally mature erythrocytes. During the differentiation process, the cells became progressively sensitive to erythropoietin that controls both the survival and proliferation of erythroid cells. A normal homeostasis of the erythropoietic system requires an appropriate balance between the rate of erythroid cell production and red blood cell destruction. Growing evidences outlined in the present review indicate that apoptotic mechanism play a relevant role in the control of erythropoiesis under physiologic and pathologic conditions. Withdrawal of erythropoietin or stimulation of death receptors such as Fas or TRAIL-Rs leads to activation of a subset of caspase-3, -7 and -8, which then cleave the transcription factors GATA-1 and TAL-1 and trigger apoptosis. In addition, there is evidence that a number of caspases are physiologically activated during erythroid differentiation and are functionally required for erythroid maturation. Several caspase substrates are cleaved in differentiating cells, including the protein acinus whose activation by cleavage is required for chromatin condensation. The studies on normal erythropoiesis have clearly indicated that immature erythroid precursors are sensitive to apoptotic triggering mediated by activation of the intrinsic and extrinsic apoptotic pathways. These apoptotic mechanisms are frequently exacerbated in some pathologic conditions, associated with the development of anemia (ie, thalassemias, multiple myeloma, myelodysplasia, aplastic anemia). The considerable progress in our understanding of the apoptotic mechanisms underlying normal and pathologic erythropoiesis may offer the way to improve the treatment of several pathologic conditions associated with the development of anemia.
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Affiliation(s)
- U Testa
- Department of Hematology and Oncology, Istituto Superiore di Sanità, Rome, Italy.
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