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Chen X, Pillay S, Lohmann F, Bieker JJ. Association of DDX5/p68 protein with the upstream erythroid enhancer element (EHS1) of the gene encoding the KLF1 transcription factor. J Biol Chem 2023; 299:105489. [PMID: 38000658 PMCID: PMC10750184 DOI: 10.1016/j.jbc.2023.105489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 10/28/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
EKLF/KLF1 is an essential transcription factor that plays a global role in erythroid transcriptional activation. Regulation of KLF1 is of interest, as it displays a highly restricted expression pattern, limited to erythroid cells and its progenitors. Here we use biochemical affinity purification to identify the DDX5/p68 protein as an activator of KLF1 by virtue of its interaction with the erythroid-specific DNAse hypersensitive site upstream enhancer element (EHS1). We further show that this protein associates with DEK and CTCF. We postulate that the range of interactions of DDX5/p68 with these and other proteins known to interact with this element render it part of the enhanseosome complex critical for optimal expression of KLF1 and enables the formation of a proper chromatin configuration at the Klf1 locus. These individual interactions provide quantitative contributions that, in sum, establish the high-level activity of the Klf1 promoter and suggest they can be selectively manipulated for clinical benefit.
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Affiliation(s)
- Xiaoyong Chen
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Sanjana Pillay
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Felix Lohmann
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA; Black Familly Stem Cell Institute, Mount Sinai School of Medicine, New York, New York, USA; Tisch Cancer Institute, Mount Sinai School of Medicine, New York, New York, USA; Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, New York, USA.
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Singha K, Teawtrakul N, Fucharoen G, Fucharoen S. Molecular and haematological characterisation of haemolytic anaemia associated with biallelic KLF1 mutations: a case series. J Clin Pathol 2023:jcp-2023-208945. [PMID: 37507221 DOI: 10.1136/jcp-2023-208945] [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: 05/08/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
AIMS Krüppel-like factor 1 (KLF1) is an erythroid-specific transcription factor playing an important role in erythropoiesis and haemoglobin (Hb) switching. Biallelic KLF1 mutations can cause haemolytic anaemia with thalassaemia-like syndromes but are rarely reported. We explore the KLF1 mutations in Thai subjects with unexplainable haemolytic anaemia. METHODS The study was done on 57 subjects presented with haemolytic anaemia and elevated Hb F without β-thalassaemia diseases. Hb analysis was performed using capillary electrophoresis. Analyses of α-thalassaemia, β-thalassaemia and KLF1 genes were performed using PCR-based methods and DNA sequencing. RESULTS Thirteen subjects with compound heterozygous for a known and five new genetic KLF1 interactions were identified, including KLF1:c.519_525dupCGGCGCC/c.892G>C with class 3/2 (n=8), and each subject with new genetic interaction, including KLF1:c.-154C>T;643C>T/c.983G>A with class 3/2, KLF1:c.-154C>T;643C>T/c.809C>G with class 3/2, KLF1:c892G>C/c.983G>A with class 2/2, KLF1:c.892G>C/c.1001C>G with class 2/2 and KLF1:c.1001C>G/c.1003G>A with class 2/2. Most of them had anaemia with Hb levels ranging from 45 to 110 g/L, hypochromic microcytosis, aniso-poikilocytosis, increased Hb F levels (17.9%-47.4%), small amounts of Hb Bart's, regular blood transfusion, hyperbilirubinaemia, increased serum ferritin and nucleated red blood cell. CONCLUSIONS Biallelic KLF1 mutations associated with anaemia may not be uncommon in Thailand. Characteristics of haemolytic anaemia, abnormal red cell morphology with nucleated red blood cells and elevated Hb F, and presenting small amounts of Hb Bart's without thalassaemia diseases are useful markers to further investigation of the KLF1 gene.
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Affiliation(s)
- Kritsada Singha
- Faculty of Medicine, Mahasarakham University, Mahasarakham, Thailand
- Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Nattiya Teawtrakul
- Division of Hematology, Department of Internal Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Goonnapa Fucharoen
- Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Supan Fucharoen
- Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
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3
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Gnanapragasam MN, Planutis A, Glassberg JA, Bieker JJ. Identification of a genomic DNA sequence that quantitatively modulates KLF1 transcription factor expression in differentiating human hematopoietic cells. Sci Rep 2023; 13:7589. [PMID: 37165057 PMCID: PMC10172341 DOI: 10.1038/s41598-023-34805-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 05/08/2023] [Indexed: 05/12/2023] Open
Abstract
The onset of erythropoiesis is under strict developmental control, with direct and indirect inputs influencing its derivation from the hematopoietic stem cell. A major regulator of this transition is KLF1/EKLF, a zinc finger transcription factor that plays a global role in all aspects of erythropoiesis. Here, we have identified a short, conserved enhancer element in KLF1 intron 1 that is important for establishing optimal levels of KLF1 in mouse and human cells. Chromatin accessibility of this site exhibits cell-type specificity and is under developmental control during the differentiation of human CD34+ cells towards the erythroid lineage. This site binds GATA1, SMAD1, TAL1, and ETV6. In vivo editing of this region in cell lines and primary cells reduces KLF1 expression quantitatively. However, we find that, similar to observations seen in pedigrees of families with KLF1 mutations, downstream effects are variable, suggesting that the global architecture of the site is buffered towards keeping the KLF1 genetic region in an active state. We propose that modification of intron 1 in both alleles is not equivalent to complete loss of function of one allele.
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Affiliation(s)
- M N Gnanapragasam
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
- Department of Biological, Geological, and Environmental Sciences, Center for Gene Regulation in Health and Disease, Cleveland State University, Cleveland, OH, USA
| | - A Planutis
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - J A Glassberg
- Department of Emergency Medicine, Hematology and Medical Oncology, Mount Sinai School of Medicine, New York, NY, USA
| | - J J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.
- Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, USA.
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, USA.
- Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY, USA.
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4
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Catapano R, Sessa R, Trombetti S, Cesaro E, Russo F, Izzo P, Makis A, Grosso M. Identification and Functional Analysis of Known and New Mutations in the Transcription Factor KLF1 Linked with β-Thalassemia-like Phenotypes. BIOLOGY 2023; 12:biology12040510. [PMID: 37106711 PMCID: PMC10135830 DOI: 10.3390/biology12040510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/31/2023]
Abstract
The erythroid transcriptional factor Krüppel-like factor 1 (KLF1) is a master regulator of erythropoiesis. Mutations that cause KLF1 haploinsufficiency have been linked to increased fetal hemoglobin (HbF) and hemoglobin A2 (HbA2) levels with ameliorative effects on the severity of β-thalassemia. With the aim of determining if KLF1 gene variations might play a role in the modulation of β-thalassemia, in this study we screened 17 subjects showing a β-thalassemia-like phenotype with a slight or marked increase in HbA2 and HbF levels. Overall, seven KLF1 gene variants were identified, of which two were novel. Functional studies were performed in K562 cells to clarify the pathogenic significance of these mutations. Our study confirmed the ameliorative effect on the thalassemia phenotype for some of these variants but also raised the notion that certain mutations may have deteriorating effects by increasing KLF1 expression levels or enhancing its transcriptional activity. Our results indicate that functional studies are required to evaluate the possible effects of KLF1 mutations, particularly in the case of the co-existence of two or more mutations that could differently contribute to KLF1 expression or transcriptional activity and consequently to the thalassemia phenotype.
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Affiliation(s)
- Rosa Catapano
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Raffaele Sessa
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Silvia Trombetti
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, 80137 Naples, Italy
| | - Elena Cesaro
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Filippo Russo
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Paola Izzo
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Alexandros Makis
- Department of Pediatrics, University Hospital of Ioannina, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Michela Grosso
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, 80131 Naples, Italy
- Correspondence:
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EKLF/Klf1 regulates erythroid transcription by its pioneering activity and selective control of RNA Pol II pause-release. Cell Rep 2022; 41:111830. [PMID: 36543143 PMCID: PMC9879271 DOI: 10.1016/j.celrep.2022.111830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/06/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022] Open
Abstract
EKLF/Klf1 is a zinc-finger transcription activator essential for erythroid lineage commitment and terminal differentiation. Using ChIP-seq, we investigate EKLF DNA binding and transcription activation mechanisms during mouse embryonic erythropoiesis. We utilize the Nan/+ mouse that expresses the EKLF-E339D (Nan) variant mutated in its conserved zinc-finger region and address the mechanism of hypomorphic and neomorphic changes in downstream gene expression. First, we show that Nan-EKLF limits normal EKLF binding to a subset of its sites. Second, we find that ectopic binding of Nan-EKLF occurs largely at enhancers and activates transcription through pioneering activity. Third, we find that for a subset of ectopic targets, gene activation is achieved in Nan/+ only by Nan-EKLF binding to distal enhancers, leading to RNA polymerase II pause-release. These results have general applicability to understanding how a DNA binding variant factor confers dominant disruptive effects on downstream gene expression even in the presence of its normal counterpart.
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Yin ZZ, Yao J, Wei FX, Chen CY, Yan HM, Zhang M. Targeted Next-Generation Sequencing Reveals a Large Novel β-Thalassemia Deletion that Removes the Entire HBB Gene. Hemoglobin 2022; 46:290-295. [PMID: 36412578 DOI: 10.1080/03630269.2022.2145964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
β-Thalassemia (β-thal) is one of the most common monogenic recessive inherited diseases worldwide. The mutation spectrum of β-thal has been increasingly broadened by various genetic testing methods. The discovery and identification of novel and rare pathogenic thalassemia variants enable better disease prevention, especially in high prevalence regions. In this study, a Chinese thalassemia family with an unclear etiology was recruited to the Thalassemia Screening Program. Blood samples collected from them were primarily screened by hematology analysis and clinical routine genetic screening. Subsequently, targeted next-generation sequencing (NGS) and Sanger sequencing were performed to find and identify a novel deletion variant. The deletion, discovered by targeted NGS, was validated through real-time quantitative polymerase chain reaction (qPCR). First, a large novel β-thal deletion (3488 bp) related to a high Hb F level, NC_000011.9: g.5245533_5249020del (Chongqing deletion) (GRCh37/hg19), was found and identified in the proband and her mother. The deletion removed the entire β-globin gene and led to absent β-globin (β0). We then validated this large novel deletion in the proband and her mother by qPCR. We first discovered and identified a large novel β-thal deletion related to elevated Hb F level, it helps broaden the spectrum of pathogenic mutants that may cause β-thal intermedia (β-TI) or β-thal major (β-TM), paving the way for effective thalassemia screening. Next-generation sequencing has the potential of finding rare and novel thalassemia mutants.
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Affiliation(s)
- Zhen-Zhen Yin
- Nanfang College, Guangzhou, People's Republic of China
| | - Jian Yao
- Nanfang College, Guangzhou, People's Republic of China
| | - Feng-Xiang Wei
- The Genetics Laboratory, Shenzhen Longgang District Maternity and Child Healthcare Hospital, Shenzhen, People's Republic of China
| | - Chu-Yan Chen
- Nanfang College, Guangzhou, People's Republic of China
| | - Hong-Mei Yan
- Guangzhou Development District Hospital, Guangzhou, People's Republic of China
| | - Ming Zhang
- Nanfang College, Guangzhou, People's Republic of China
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Kang Y, Lin J, Wang L, Shen X, Li J, Wu A, Yue L, Wei L, Ye Y, Yang J, Wu J. Hirsutine, a novel megakaryopoiesis inducer, promotes thrombopoiesis via MEK/ERK/FOG1/TAL1 signaling. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 102:154150. [PMID: 35569185 DOI: 10.1016/j.phymed.2022.154150] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 04/11/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Thrombocytopenia (TP) remains a challenge in clinical hematology. TP may have serious consequences, such as recurrent skin and mucosal bleeding and increased risk of intracranial and internal organ hemorrhage. However, effective and safe therapeutic drugs for the long-term management of TP are still lacking. PURPOSE This study aimed to identify more effective active compounds for TP therapy. METHODS Liquid chromatography-mass spectrometry-nuclear magnetic resonance analysis was used to confirm the medicinal species and chemical structure of Hirsutine (HS). The proliferation of HS was examined by Cell Counting Kit (CCK-8) assay on cells lines. The effect of HS on megakaryocyte differentiation was analyzed by evaluating the expression of CD41, CD42b, and DNA ploidy via flow cytometry (FCM). The morphology of megakaryocytes and intermediate cells was observed using an optical microscope. K562 cells were then stained with Giemsa and benzidine. qRT-PCR was used to examine the mRNA expression of GATA-1, GATA-2, FOG-1, TAL-1, RUNX-1, NF-E2, and KLF-1 in K562 cells. Protein levels of the transcription factors were analyzed by western blotting. An MEK inhibitor was used to verify the relationship between the MEK/ERK signaling pathway and CD41/CD42b (FCM), FOG-1, and TAL-1. The Kunming thrombocytopenia mouse model was established by X-ray irradiation (4 Gy) and used to test HS activity and related hematopoietic organ index in vivo. Finally, computer simulations of molecular docking were used to predict the binding energies between HS-MEK and HS-ERK. RESULTS We preliminarily identified HS by screening a plant-sourced compound library for natural compounds with megakaryocytic differentiation and maturation (MKD/MKM)-promoting activity. We found that HS not only enhanced MKD/MKM of K562 and Meg01 cells, but also suppressed the decline of peripheral platelet levels in X-ray-induced myelosuppressive mice. In addition, HS promoted MKD via activation of MEK-ERK-FOG1/TAL1 signaling, which may be the key molecular mechanism of HS action in TP treatment. Molecular docking simulations further verified that HS targets the signaling protein MEK with high-affinity. CONCLUSION In this study, we report for the first time that hirsutine boosts MKD/MKM through the MEK/ERK/FOG1/TAL1 signaling pathway and thus represents a promising treatment option for TP.
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Affiliation(s)
- Yaqi Kang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China; State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Jing Lin
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Long Wang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Xin Shen
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Jingyan Li
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China; Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Anguo Wu
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Liang Yue
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Liuping Wei
- Department of Pharmacy, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yun Ye
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China; Department of Pharmacy, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Jing Yang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Jianming Wu
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China; Department of Pharmacy, Affiliated Hospital of Southwest Medical University, Luzhou, China.
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8
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King R, Gallagher PJ, Khoriaty R. The congenital dyserythropoieitic anemias: genetics and pathophysiology. Curr Opin Hematol 2022; 29:126-136. [PMID: 35441598 PMCID: PMC9021540 DOI: 10.1097/moh.0000000000000697] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW The congenital dyserythropoietic anemias (CDA) are hereditary disorders characterized by ineffective erythropoiesis. This review evaluates newly developed CDA disease models, the latest advances in understanding the pathogenesis of the CDAs, and recently identified CDA genes. RECENT FINDINGS Mice exhibiting features of CDAI were recently generated, demonstrating that Codanin-1 (encoded by Cdan1) is essential for primitive erythropoiesis. Additionally, Codanin-1 was found to physically interact with CDIN1, suggesting that mutations in CDAN1 and CDIN1 result in CDAI via a common mechanism. Recent advances in CDAII (which results from SEC23B mutations) have also been made. SEC23B was found to functionally overlap with its paralogous protein, SEC23A, likely explaining the absence of CDAII in SEC23B-deficient mice. In contrast, mice with erythroid-specific deletion of 3 or 4 of the Sec23 alleles exhibited features of CDAII. Increased SEC23A expression rescued the CDAII erythroid defect, suggesting a novel therapeutic strategy for the disease. Additional recent advances included the identification of new CDA genes, RACGAP1 and VPS4A, in CDAIII and a syndromic CDA type, respectively. SUMMARY Establishing cellular and animal models of CDA is expected to result in improved understanding of the pathogenesis of these disorders, which may ultimately lead to the development of new therapies.
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Affiliation(s)
- Richard King
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, Michigan, USA
| | - Patrick J. Gallagher
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Rami Khoriaty
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- University of Michigan Rogel Cancer Center, Ann Arbor, Michigan, USA
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, USA
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
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9
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Mukherjee K, Bieker JJ. Transcriptional Control of Gene Expression and the Heterogeneous Cellular Identity of Erythroblastic Island Macrophages. Front Genet 2021; 12:756028. [PMID: 34880902 PMCID: PMC8646026 DOI: 10.3389/fgene.2021.756028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
During definitive erythropoiesis, maturation of erythroid progenitors into enucleated reticulocytes requires the erythroblastic island (EBI) niche comprising a central macrophage attached to differentiating erythroid progenitors. Normally, the macrophage provides a nurturing environment for maturation of erythroid cells. Its critical physiologic importance entails aiding in recovery from anemic insults, such as systemic stress or acquired disease. Considerable interest in characterizing the central macrophage of the island niche led to the identification of putative cell surface markers enriched in island macrophages, enabling isolation and characterization. Recent studies focus on bulk and single cell transcriptomics of the island macrophage during adult steady-state erythropoiesis and embryonic erythropoiesis. They reveal that the island macrophage is a distinct cell type but with widespread cellular heterogeneity, likely suggesting distinct developmental origins and biological function. These studies have also uncovered transcriptional programs that drive gene expression in the island macrophage. Strikingly, the master erythroid regulator EKLF/Klf1 seems to also play a major role in specifying gene expression in island macrophages, including a putative EKLF/Klf1-dependent transcription circuit. Our present review and analysis of mouse single cell genetic patterns suggest novel expression characteristics that will enable a clear enrichment of EBI subtypes and resolution of island macrophage heterogeneity. Specifically, the discovery of markers such as Epor, and specific features for EKLF/Klf1-expressing island macrophages such as Sptb and Add2, or for SpiC-expressing island macrophage such as Timd4, or for Maf/Nr1h3-expressing island macrophage such as Vcam1, opens exciting possibilities for further characterization of these unique macrophage cell types in the context of their critical developmental function.
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Affiliation(s)
- Kaustav Mukherjee
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, United States.,Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY, United States
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, United States.,Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY, United States.,Tisch Cancer Center, Mount Sinai School of Medicine, New York, NY, United States.,Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY, United States
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10
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Colaco S, Nadkarni A. Borderline HbA 2 levels: Dilemma in diagnosis of beta-thalassemia carriers. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2021; 788:108387. [PMID: 34893152 DOI: 10.1016/j.mrrev.2021.108387] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 05/27/2021] [Accepted: 06/08/2021] [Indexed: 12/17/2022]
Abstract
There is inconsistency in the exact definition of diagnostic levels of HbA2 for β thalassemia trait. While many laboratories consider HbA2 ≥4.0 % diagnostic, still others consider HbA2 ≥3.3 % or HbA2 ≥3.5 % as the cut-off for establishing β thalassemia carrier diagnosis. This is because, over the years, studies have described β thalassemia carriers showing HbA2 levels that lie above the normal range of HbA2 but below the typical carrier range of β thalassemia. These, "borderline HbA2 levels", though not detrimental to health, are significant in β thalassemia carrier diagnosis because they can lead to misinterpretation of results. In this review, we have evaluated the prevalence of borderline HbA2 levels and discussed the causes of borderline HbA2 values. We have also compiled an extensive catalogue of β globin gene defects associated with borderline HbA2 levels and have discussed strategies to avoid misdiagnosing borderline HbA2 β thalassemia carriers. Our analysis of studies that have delineated the cause of borderline HbA2 levels in different populations shows that 35.4 % [626/1766] of all individuals with borderline HbA2 levels carry a molecular defect. Among the positive samples, 17 % [299/1766] show β globin gene defects, 7.7 % [137/1766] show α thalassemia defects, 2.7 % [49/1766] show KLF1 gene mutations, 2.3 % [41/1766] show the co-inheritance of β and α thalassemia, 2.0 % [37/1766] show the co-inheritance of β and δ thalassemia and 1.8 % [32/1766] show α globin gene triplication. It appears that a comprehensive molecular work up of the β globin gene is the only definite method to detect borderline HbA2 β thalassemia carriers, especially in populations with a high prevalence of the disease. The presence of associated genetic or acquired determinants may subsequently be assessed to identify the cause of borderline HbA2.
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Affiliation(s)
- Stacy Colaco
- Department of Hematogenetics, ICMR-National Institute of Immunohematology, 13th Floor, K.E.M. Hospital Campus, Parel, Mumbai, 400 012, India
| | - Anita Nadkarni
- Department of Hematogenetics, ICMR-National Institute of Immunohematology, 13th Floor, K.E.M. Hospital Campus, Parel, Mumbai, 400 012, India.
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11
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GPS2 promotes erythroid differentiation by control of the stability of EKLF protein. Blood 2021; 135:2302-2315. [PMID: 32384137 DOI: 10.1182/blood.2019003867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/05/2020] [Indexed: 02/08/2023] Open
Abstract
Erythropoiesis is a complex multistage process that involves differentiation of early erythroid progenitors to enucleated mature red blood cells, in which lineage-specific transcription factors play essential roles. Erythroid Krüppel-like factor (EKLF/KLF1) is a pleiotropic erythroid transcription factor that is required for the proper maturation of the erythroid cells, whose expression and activation are tightly controlled in a temporal and differentiation stage-specific manner. Here, we uncover a novel role of G-protein pathway suppressor 2 (GPS2), a subunit of the nuclear receptor corepressor/silencing mediator of retinoic acid and thyroid hormone receptor corepressor complex, in erythrocyte differentiation. Our study demonstrates that knockdown of GPS2 significantly suppresses erythroid differentiation of human CD34+ cells cultured in vitro and xenotransplanted in nonobese diabetic/severe combined immunodeficiency/interleukin-2 receptor γ-chain null mice. Moreover, global deletion of GPS2 in mice causes impaired erythropoiesis in the fetal liver and leads to severe anemia. Flow cytometric analysis and Wright-Giemsa staining show a defective differentiation at late stages of erythropoiesis in Gps2-/- embryos. Mechanistically, GPS2 interacts with EKLF and prevents proteasome-mediated degradation of EKLF, thereby increasing EKLF stability and transcriptional activity. Moreover, we identify the amino acids 191-230 region in EKLF protein, responsible for GPS2 binding, that is highly conserved in mammals and essential for EKLF protein stability. Collectively, our study uncovers a previously unknown role of GPS2 as a posttranslational regulator that enhances the stability of EKLF protein and thereby promotes erythroid differentiation.
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12
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Kulczynska-Figurny K, Bieker JJ, Siatecka M. Severe anemia caused by dominant mutations in Krüppel-like factor 1 (KLF1). MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 786:108336. [PMID: 33339573 DOI: 10.1016/j.mrrev.2020.108336] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/23/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The etiology and severity of anemia, a common blood disorder, are diverse. Dominant mutations in Krüppel-like factor 1 (KLF1/EKLF) underlie the molecular basis for some of them. KLF1 is a zinc finger transcription factor that plays an essential role in red blood cell proliferation and differentiation. Mutations have been identified in the KLF1 gene that cause hematologic diseases. Two of these alter one allele but generate an extreme phenotype: the mouse Nan mutation (E339D) leads to hemolytic neonatal anemia with hereditary spherocytosis, and the human CDA mutation (E325K) causes congenital dyserythropoietic anemia (CDA) type IV. These modify functionally important amino acids in the zinc finger DNA-binding domain at positions involved in direct interactions with regulatory elements of KLF1's target genes. Although the two dominant mutations alter the same evolutionarily conserved glutamic acid residue, the substitutions are not equivalent and lead to divergent consequences for the molecular mechanisms underlying activity of these mutants, particularly in recognition and interaction with their unique binding sites. Consequently, the properties of the protein are transformed such that it acquires novel dominant characteristics whose effects may not be limited to the erythroid compartment. KLF1 mutants cause loss-of-function/haploinsufficiency effects on some KLF1 wild-type target genes, while at the same time gain-of-function effects activate ectopic sites and neomorphic gene expression. Such anomalies not only lead to intrinsic red cell problems, but also to expression of non-erythroid genes that systemically disturb organ development. This review highlights recent molecular, biochemical, and genetic studies of KLF1 mutants, particularly the dramatic consequences that come from just a single amino acid change. The study of these variants provides an important contribution to the overall understanding of the DNA-protein interface of the zinc finger subtype of transcription factors, and the potential clinical consequences of what might appear to be a minor change in sequence.
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Affiliation(s)
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Miroslawa Siatecka
- Department of Genetics, Faculty of Biology, University of Adam Mickiewicz, Poznan, 61-614, Poland.
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13
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Mansoor A, Mansoor MO, Patel JL, Zhao S, Natkunam Y, Bieker JJ. KLF1/EKLF expression in acute leukemia is correlated with chromosomal abnormalities. Blood Cells Mol Dis 2020; 83:102434. [PMID: 32311573 DOI: 10.1016/j.bcmd.2020.102434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/20/2020] [Accepted: 03/20/2020] [Indexed: 12/15/2022]
Abstract
KLF1 (EKLF) is a master regulator of erythropoiesis and controls expression of a wide array of target genes. We interrogated human tissue microarray samples via immunohistological analysis to address whether levels of KLF1 protein are associated with leukemia. We have made the unexpected findings that higher KLF1 levels are correlated with cells containing abnormal chromosomes, and that high KLF1 expression is not limited to acute myeloid leukemia (AML) associated with erythroid/megakaryoblastic differentiation. Expression of KLF1 is associated with poor survival. Further analyses reveal that KLF1 directly regulates a number of genes that play a role in chromosomal integrity. Together these results suggest that monitoring KLF1 levels may provide a new marker for risk stratification and prognosis in patients with AML.
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Affiliation(s)
- Adnan Mansoor
- Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Canada
| | - Mohammad Omer Mansoor
- Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Canada
| | - Jay L Patel
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | - Shuchun Zhao
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Yasodha Natkunam
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - James J Bieker
- Department of Cell, Developmental, & Regenerative Biology, Black Family Stem Cell Institute, Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA.
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14
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Jiang H, Jiang F, Li J, Tang F, Li DZ. Congenital Nonspherocytic Hemolytic Anemia Caused by Krüppel-Like Factor 1 Gene Variants: Another Case Report. Hemoglobin 2019; 43:292-295. [PMID: 31645145 DOI: 10.1080/03630269.2019.1680384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In this study, we report on a compound heterozygote for variants in the key erythroid transcription factor Krüppel-like factor 1 (KLF1) gene in a patient who presented with severe, transfusion-dependent hemolytic anemia. The red cells were normochromic and normocytic, and resembled those seen in patients with congenital nonspherocytic hemolytic anemia (CNSHA). Next generation sequencing (NGS) revealed that the patient was a compound heterozygote for the KLF1 frameshift variant c.519_525dup (p.Gly176ArgfsTer179) and a missense variant c.1012C>A (p.Pro338Thr). This report adds to the wide clinical spectrum of KLF1 gene variants. We suggest that loss of KLF1 should be considered in otherwise unexplained cases of congenital hemolytic anemia.
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Affiliation(s)
- Hua Jiang
- Department of Pediatric Hematology-Oncology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Fan Jiang
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Jian Li
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Fang Tang
- Neonatal Screening Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, People's Republic of China
| | - Dong-Zhi Li
- Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, People's Republic of China
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15
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Fanis P, Kousiappa I, Phylactides M, Kyrri A, Hadjigavriel M, Christou S, Sitarou M, Kleanthous M. A novel mutation in the erythroid transcription factor KLF1 is likely responsible for ameliorating β-thalassemia major. Hum Mutat 2019; 40:1768-1780. [PMID: 31115947 PMCID: PMC6790707 DOI: 10.1002/humu.23817] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/02/2019] [Accepted: 05/05/2019] [Indexed: 12/02/2022]
Abstract
We describe the identification of a novel missense mutation in the second zinc finger of KLF1 in two siblings who, based on their genotype, are predicted to suffer from beta thalassemia major but are, in fact, transfusion‐free and in good health. These individuals, as well as two additional members of the same family also carrying this KLF1 mutation, exhibit high levels of fetal hemoglobin (HbF). KLF1 is an erythroid transcription factor, which plays a critical role in the regulation of the developmental switch between fetal and adult hemoglobin by regulating the expression of a multitude of genes including that of BCL11A. The mutation appears to be the main candidate responsible for the beta thalassemia‐ameliorating effect as this segregates with the observed phenotype and also exogenous expression of the KLF1 mutant protein in human erythroid progenitor cells resulted in the induction of γ‐globin, without, however, affecting BCL11A levels. This report adds to the weight of evidence that heterozygous KLF1 mutations can ameliorate the severity of the β‐thalassemia major phenotype.
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Affiliation(s)
- Pavlos Fanis
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Ioanna Kousiappa
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Marios Phylactides
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Andreani Kyrri
- Population Screening Laboratory, Archbishop Makarios III Hospital, Nicosia, Cyprus
| | | | | | - Maria Sitarou
- Thalassaemia Clinic, Larnaca General Hospital, Larnaca, Cyprus
| | - Marina Kleanthous
- Molecular Genetics Thalassaemia Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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16
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Varricchio L, Planutis A, Manwani D, Jaffray J, Mitchell WB, Migliaccio AR, Bieker JJ. Genetic disarray follows mutant KLF1-E325K expression in a congenital dyserythropoietic anemia patient. Haematologica 2019; 104:2372-2380. [PMID: 30872368 PMCID: PMC6959163 DOI: 10.3324/haematol.2018.209858] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/12/2019] [Indexed: 12/20/2022] Open
Abstract
Congenital dyserythropoietic anemia type IV is caused by a heterozygous mutation, Glu325Lys (E325K), in the KLF1 transcription factor. Molecular characteristics of this disease have not been clarified, partly due to its rarity. We expanded erythroid cells from a patient's peripheral blood and analyzed its global expression pattern. We find that a large number of erythroid pathways are disrupted, particularly those related to membrane transport, globin regulation, and iron utilization. The altered genetics lead to significant deficits in differentiation. Glu325 is within the KLF1 zinc finger domain at an amino acid critical for site specific DNA binding. The change to Lys is predicted to significantly alter the target site recognition sequence, both by subverting normal recognition and by enabling interaction with novel sites. Consistent with this, we find high level ectopic expression of genes not normally present in the red cell. These altered properties explain patients' clinical and phenotypic features, and elucidate the dominant character of the mutation.
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Affiliation(s)
- Lilian Varricchio
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Antanas Planutis
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Deepa Manwani
- Division of Hematology/Oncology, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Julie Jaffray
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - W Beau Mitchell
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Anna Rita Migliaccio
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Dipartimento di Scienze Biomediche e NeuroMotorie, Alma Mater Studiorum, Università di Bologna, Bologna, Italy
| | - James J Bieker
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA .,Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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17
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Tamaddoni A, Khabaz Astaneh S, Tabaripour R, Akhavan-Niaki H. Krüppel-Like Factor 1 Gene Mutations in Thalassemia Patients from North Iran: Report of a New Mutation Associated with β-Thalassemia Intermedia. Hemoglobin 2019; 43:12-17. [PMID: 30747024 DOI: 10.1080/03630269.2019.1567528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Thalassemia is a hereditary disease with an autosomal recessive inheritance pattern resulting in reduced production of globin chains. Mutations in modifier genes can cause or affect thalassemia. Krüppel-like factor 1 (KLF1) is a modifier gene that was investigated in this study. Thirty-five Iranian β-thalassemia (β-thal) minor patients with hematological symptoms including Hb A2 3.0%, mean corpuscular volume (MCV) <75.0 fL, mean corpuscular hemoglobin (Hb) (MCH) <25.0 pg, and two β-thal intermedia (β-TI) patients in 50 subjects who carried no mutations on the HBB and HBA2 or HBA1 genes were investigated for all exons of the KLF1 gene by polymerase chain reaction (PCR) and sequencing methods. Of the 35 patients with a β-thal minor phenotype, one patient was heterozygous for the c.544T>C mutation in exon 2 of KLF1 and HBB: c.380T>G variant, Hb Dhonburi [also known as Hb Neapolis or codon 126 (T>G)]. The c.340T>C mutation was also found in exon 2 of the KLF1 gene with an allele frequency of 16.6% in the studied β-thal carriers. The two β-TI patients were homozygous for a new mutation c.942delA in exon 3 of KLF1. Mutations in modifier genes can cause or affect thalassemia. Therefore, exact investigation of globin genes and modifiers such as KLF1 is necessary in areas where globin gene disorders are most prevalent to understand the reason of clinical and hematological symptoms of thalassemia and facilitate newborn screening or prenatal diagnosis (PND) programs.
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Affiliation(s)
- Ahmad Tamaddoni
- a Non-Communicable Pediatric Diseases Research Center, Health Research Institute, Babol University of Medical Sciences , Babol , Iran
| | - Sahar Khabaz Astaneh
- b Department of Cellular and Molecular Biology , Islamic Azad University , Babol Branch , Babol , Iran
| | - Reza Tabaripour
- b Department of Cellular and Molecular Biology , Islamic Azad University , Babol Branch , Babol , Iran
| | - Haleh Akhavan-Niaki
- c Department of Genetics, Faculty of Medicine , Babol University of Medical Sciences , Babol , Iran
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18
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Hariharan P, Colah R, Ghosh K, Nadkarni A. Differential role of Kruppel like factor 1 (KLF1) gene in red blood cell disorders. Genomics 2018; 111:1771-1776. [PMID: 30529538 DOI: 10.1016/j.ygeno.2018.11.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/27/2018] [Accepted: 11/30/2018] [Indexed: 01/06/2023]
Abstract
The master erythroid regulator KLF1,plays a pivotal role during erythroid lineage development by regulating the expression of many erythroid genes. Variations in the KLF1 gene are found to be associated with varied erythroid phenotypes. With the aim of determining the role of KLF1 gene variations in HbF induction and their genotype phenotype relationship, in this study, we screened 370 individuals with different hemoglobinopathy condition. Hematological analysis was carried out using automated blood cell counter and Variant II HPLC (Biorad). KLF1 gene mutations were screened using automated DNA sequencing. Expression analysis was carried out using q-RT PCR of KLF1, BCL11A and γ-globin after selective enrichment and culturing of CD 34 +ve cells into an erythroid lineage. Over all 14 KLF1 gene variations were identified, of which six variants were novel. The incidence of KLF1 gene mutations was found to be 8.1%. It was seen that KLF1 mutations contributed in borderline HbA2 levels as 7.6% of our borderline HbA2 cases showed presence of KLF1 variations. It also contributed in induction of HbF levels under stress erythropoietic conditions. Gene expression studies revealed inverse correlation of KLF1, BCL11A (reduced) with γ-globin gene expression (increased) in patients showing KLF1 gene mutations, thus indicating the role of KLF1 gene in regulating the γ-globin gene expression. The identification of genomic variants of the KLF1 may help in determining the functionally active domain of this protein and will facilitate in understanding the wide spectrum of phenotypes generated by these variants.
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Affiliation(s)
- Priya Hariharan
- National Institute of Immunohematology (ICMR), 13th Floor, New Multi-storeyed Building, K.E.M. Hospital Campus, Parel, Mumbai 400012, India
| | - Roshan Colah
- National Institute of Immunohematology (ICMR), 13th Floor, New Multi-storeyed Building, K.E.M. Hospital Campus, Parel, Mumbai 400012, India
| | - Kanjaksha Ghosh
- National Institute of Immunohematology (ICMR), 13th Floor, New Multi-storeyed Building, K.E.M. Hospital Campus, Parel, Mumbai 400012, India
| | - Anita Nadkarni
- National Institute of Immunohematology (ICMR), 13th Floor, New Multi-storeyed Building, K.E.M. Hospital Campus, Parel, Mumbai 400012, India.
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19
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Jiang F, Qu YX, Chen GL, Li J, Zhou JY, Zuo LD, Liao C, Li DZ. KFL1 Gene Variants in α-Thalassemia Individuals with Increased Fetal Hemoglobin in a Chinese Population. Hemoglobin 2018; 42:161-165. [PMID: 30205725 DOI: 10.1080/03630269.2018.1486325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Krüppel-like factor 1 (KLF1) is a pleiotropic erythroid transcription factor that is a regulator of definitive erythropoiesis. The aim of this study was to detect KLF1 gene variants in α-thalassemia (α-thal) carriers with an increased Hb F level in a Chinese population, and determine the changes of hematological parameters as a result of interactions between KLF1 gene mutations and α-thal. Subjects with α-thal and Hb F levels of ≥1.0% were selected for further investigation. Direct sequencing was used to detect KLF1 gene mutations. Hematological parameters of subjects with α-thal and concomitant KLF1 gene mutations and those with α-thal alone were compared. The KLF1 gene variants were detected in 46 of 275 (16.7%) individuals with α-thal and Hb F levels of ≥1.0%. The detection rate of KLF1 gene mutations rose correspondingly when the Hb F level increased. For α0-thal carriers, significantly lower mean corpuscular volume (MCV) and mean corpuscular hemoglobin (Hb) (MCH) values were observed in KLF1 gene mutation-positive carriers than that in KLF1 gene mutation-free carriers; conversely, significantly higher Hb A2 and Hb F levels were observed in the former condition rather than in the latter condition. The results of this study indicate that KLF1 gene variants are common in Chinese subjects with α-thal and increased Hb F levels, and KLF1 gene mutations decreased the red blood cell (RBC) indices in α-thal carriers as that in normal adults.
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Affiliation(s)
- Fan Jiang
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Yan-Xia Qu
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Gui-Lan Chen
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Jian Li
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Jian-Ying Zhou
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Lian-Dong Zuo
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Can Liao
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
| | - Dong-Zhi Li
- a Guangzhou Women and Children's Medical Center , Guangzhou Medical University , Guangzhou , Guangdong Province , People's Republic of China
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20
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Gnanapragasam MN, Crispino JD, Ali AM, Weinberg R, Hoffman R, Raza A, Bieker JJ. Survey and evaluation of mutations in the human KLF1 transcription unit. Sci Rep 2018; 8:6587. [PMID: 29700354 PMCID: PMC5920080 DOI: 10.1038/s41598-018-24962-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/12/2018] [Indexed: 01/03/2023] Open
Abstract
Erythroid Krüppel-like Factor (EKLF/KLF1) is an erythroid-enriched transcription factor that plays a global role in all aspects of erythropoiesis, including cell cycle control and differentiation. We queried whether its mutation might play a role in red cell malignancies by genomic sequencing of the KLF1 transcription unit in cell lines, erythroid neoplasms, dysplastic disorders, and leukemia. In addition, we queried published databases from a number of varied sources. In all cases we only found changes in commonly notated SNPs. Our results suggest that if there are mutations in KLF1 associated with erythroid malignancies, they are exceedingly rare.
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Affiliation(s)
- Merlin Nithya Gnanapragasam
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | - John D Crispino
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Abdullah M Ali
- Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Rona Weinberg
- Cellular Therapy Laboratory, New York Blood Center, New York, NY, 10065, USA
| | - Ronald Hoffman
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, 10029, USA
| | - Azra Raza
- Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - James J Bieker
- Department of Cell, Developmental, and Regenerative Biology, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Black Familly Stem Cell Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
- Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY, 10029, USA.
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21
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Hamid M, Ershadi Oskouei S, Shariati G, Babaei E, Galehdari H, Saberi A, Sedaghat A. Mutation Screening of the Krüppel-like Factor 1 Gene in Individuals With Increased Fetal Hemoglobin Referred for Hemoglobinopathy Investigation in South of Iran. J Pediatr Hematol Oncol 2018; 40:192-195. [PMID: 29420372 DOI: 10.1097/mph.0000000000001093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Any mutation in the Krüppel-like factor 1 (KLF1) gene may interfere with its proper related function in the erythropoiesis process and lead to alterations in proper activation of its downstream protein through globin switching, which results in an increase in fetal hemoglobin (HbF). This study aimed to investigate whether KLF1 mutation can associate with high level of HbF in individuals with increased fetal hemoglobin referred for screening of hemoglobinopathies in south of Iran. MATERIALS AND METHODS The human KLF1 gene was amplified via the polymerase chain reaction procedure, and sequencing was used to determine any mutation in these patients. Moreover, XmnI polymorphisms in the position of -158 of γ-globin gene promoter were analyzed in all patients by polymerase chain reaction restriction fragment length polymorphism. RESULT Analysis of sequencing revealed a missense mutation in the KLF1 gene, p.Ser102Pro (c.304T>C), which was detectable in 10 of 23 cases with elevated HbF level. This mutation was only detected in individuals who had a HbF level between 3.1% and 25.6%. Statistical analysis showed that the frequency of C allele is significantly correlated with a high level of HbF (P<0.05). The allele frequency of positive result of XmnI polymorphism in individuals with increased HbF level was also significant, which showed an association with increased HbF level (P<0.05). CONCLUSIONS To the best of our knowledge, this is the first report of p.Ser102Pro (c.304T>C) in the KLF1 gene in β-thalassemia patients with increased level of fetal hemoglobin. According to statistical results of p.Ser102Pro mutation and XmnI polymorphism, it has been strongly suggested that both polymorphisms have an association with increased HbF samples. These nucleotide changes alone may not be the only elements raising the level of HbF, and other regulatory and modifying factors also play a role in HbF production.
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Affiliation(s)
- Mohammad Hamid
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran
| | | | - Gholamreza Shariati
- Department of Medical Genetics, Faculty of Medicine.,Narges Medical Genetics & PND Laboratory, Kianpars, Ahvaz, Iran
| | - Esmaeil Babaei
- Department of Biology, School of Natural Science, University of Tabriz, Tabriz
| | | | | | - Alireza Sedaghat
- Health Research Institute, Diabetes Research Center, Ahvaz Jundishapur University of Medical Sciences.,Narges Medical Genetics & PND Laboratory, Kianpars, Ahvaz, Iran
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22
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Huang LY, Li J, Zhang Y, Li DZ. A KLF1
gene mutation causes β-thalassemia minor in a Chinese family. Int J Lab Hematol 2018; 40:e35-e37. [DOI: 10.1111/ijlh.12788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 01/16/2018] [Indexed: 11/29/2022]
Affiliation(s)
- L.-Y. Huang
- Guangzhou Women and Children Medical Center affiliated to Guangzhou Medical University; Guangzhou Guangdong China
| | - J. Li
- Guangzhou Women and Children Medical Center affiliated to Guangzhou Medical University; Guangzhou Guangdong China
| | | | - D.-Z. Li
- Guangzhou Women and Children Medical Center affiliated to Guangzhou Medical University; Guangzhou Guangdong China
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23
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Abstract
PURPOSE OF REVIEW Transcriptional regulators provide the molecular and biochemical basis for the cell specific properties and characteristics that follow from their central role in establishing tissue-restricted expression. Precise and sequential control of terminal cell divisions, nuclear condensation, and enucleation are defining characteristics within erythropoietic differentiation. This review is focused on KLF1, a central global regulator of this process. RECENT FINDINGS Studies in the past year have brought a number of proteins that are targets of KLF1 regulation into focus with respect to their roles in terminal erythroid differentiation. Many of these are involved in fine control of the cell cycle at both early (E2F2, Cyclin A2) and later (p18, p27, p19) stages of differentiation, or are directly involved in enucleation (p18, p27). Dramatic biophysical changes controlled at the nuclear lamin by caspase 3 enable histone release and nuclear condensation, whereas dematin association with structural proteins alters the timing of enucleation. Conditional ablation of mDia2 has established its role in late stage cell cycle and enucleation. SUMMARY Transcription factors such as KLF1, along with epigenetic modifiers, play crucial roles in establishing the proper onset and progression of terminal differentiation events. Studies from the past year show a remarkable multifaceted convergence on cell cycle control, and establish that the orthochromatic erythroblast stage is a critical nodal point for many of the effects on enucleation. These studies are relevant to understanding the underlying causes of anemia and hematologic disease where defective enucleation predicts a poor clinical outcome.
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24
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Planutis A, Xue L, Trainor CD, Dangeti M, Gillinder K, Siatecka M, Nebor D, Peters LL, Perkins AC, Bieker JJ. Neomorphic effects of the neonatal anemia (Nan-Eklf) mutation contribute to deficits throughout development. Development 2017; 144:430-440. [PMID: 28143845 DOI: 10.1242/dev.145656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/18/2016] [Indexed: 12/20/2022]
Abstract
Transcription factor control of cell-specific downstream targets can be significantly altered when the controlling factor is mutated. We show that the semi-dominant neonatal anemia (Nan) mutation in the EKLF/KLF1 transcription factor leads to ectopic expression of proteins that are not normally expressed in the red blood cell, leading to systemic effects that exacerbate the intrinsic anemia in the adult and alter correct development in the early embryo. Even when expressed as a heterozygote, the Nan-EKLF protein accomplishes this by direct binding and aberrant activation of genes encoding secreted factors that exert a negative effect on erythropoiesis and iron use. Our data form the basis for a novel mechanism of physiological deficiency that is relevant to human dyserythropoietic anemia and likely other disease states.
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Affiliation(s)
- Antanas Planutis
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Li Xue
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Cecelia D Trainor
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Mohan Dangeti
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Kevin Gillinder
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia
| | - Miroslawa Siatecka
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Genetics, University of Adam Mickiewicz, Poznan 61-614, Poland
| | | | | | - Andrew C Perkins
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia.,Princess Alexandra Hospital, Brisbane QLD 4102, Queensland, Australia
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA .,Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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Hariharan P, Sawant M, Gorivale M, Manchanda R, Colah R, Ghosh K, Nadkarni A. Synergistic effect of two β globin gene cluster mutations leading to the hereditary persistence of fetal hemoglobin (HPFH) phenotype. Mol Biol Rep 2017; 44:413-417. [DOI: 10.1007/s11033-017-4125-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 08/29/2017] [Indexed: 10/18/2022]
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Satta S, Paglietti ME, Sollaino MC, Barella S, Moi P, Desogus MF, Demartis FR, Manunza L, Origa R. Changes in HbA2 and HbF in alpha thalassemia carriers with KLF1 mutation. Blood Cells Mol Dis 2017; 64:30-32. [DOI: 10.1016/j.bcmd.2017.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/16/2017] [Accepted: 03/17/2017] [Indexed: 12/29/2022]
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Lee HHL, Mak ASL, Kou KO, Poon CF, Wong WS, Chiu KH, Au PKC, Chan KYK, Kan ASY, Tang MHY, Leung KY. An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations. Hemoglobin 2017; 40:431-434. [PMID: 28361594 DOI: 10.1080/03630269.2016.1267017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.
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Affiliation(s)
- Helena H L Lee
- a Department of Obstetrics and Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - Annisa S L Mak
- a Department of Obstetrics and Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - K O Kou
- a Department of Obstetrics and Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - C F Poon
- a Department of Obstetrics and Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - W S Wong
- b Department of Clinical Pathology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - K H Chiu
- c Department of Paediatrics , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
| | - Patrick K C Au
- d Prenatal Diagnostic Laboratory, Department of Obstetrics and Gynaecology, Tsan Yuk Hospital , The University of Hong Kong , Hong Kong SAR , People's Republic of China
| | - Kelvin Y K Chan
- d Prenatal Diagnostic Laboratory, Department of Obstetrics and Gynaecology, Tsan Yuk Hospital , The University of Hong Kong , Hong Kong SAR , People's Republic of China
| | - Anita S Y Kan
- d Prenatal Diagnostic Laboratory, Department of Obstetrics and Gynaecology, Tsan Yuk Hospital , The University of Hong Kong , Hong Kong SAR , People's Republic of China
| | - Mary H Y Tang
- d Prenatal Diagnostic Laboratory, Department of Obstetrics and Gynaecology, Tsan Yuk Hospital , The University of Hong Kong , Hong Kong SAR , People's Republic of China
| | - K Y Leung
- a Department of Obstetrics and Gynaecology , Queen Elizabeth Hospital , Hong Kong SAR , People's Republic of China
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28
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Hariharan P, Gorivale M, Colah R, Ghosh K, Nadkarni A. Does the Novel KLF1
Gene Mutation Lead to a Delay in Fetal Hemoglobin Switch? Ann Hum Genet 2017; 81:125-128. [DOI: 10.1111/ahg.12191] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/28/2017] [Indexed: 01/10/2023]
Affiliation(s)
- Priya Hariharan
- Department of Haematogenetics; National Institute of Immunohaematology (ICMR); Parel Mumbai India
| | - Manju Gorivale
- Department of Haematogenetics; National Institute of Immunohaematology (ICMR); Parel Mumbai India
| | - Roshan Colah
- Department of Haematogenetics; National Institute of Immunohaematology (ICMR); Parel Mumbai India
| | - Kanjaksha Ghosh
- Blood Bank; Surat Raktadan Kendra & Research Centre; Surat Gujarat India
| | - Anita Nadkarni
- Department of Haematogenetics; National Institute of Immunohaematology (ICMR); Parel Mumbai India
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29
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de-la-Iglesia-Iñigo S, Moreno-Carralero MI, Lemes-Castellano A, Molero-Labarta T, Méndez M, Morán-Jiménez MJ. A case of congenital dyserythropoietic anemia type IV. Clin Case Rep 2017; 5:248-252. [PMID: 28265383 PMCID: PMC5331261 DOI: 10.1002/ccr3.825] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 12/02/2016] [Accepted: 12/15/2016] [Indexed: 01/15/2023] Open
Abstract
Congenital dyserythropoietic anemias (CDAs) are displayed by ineffective erythropoiesis. The wide variety of phenotypes observed in CDA patients makes differential diagnosis difficult; identification of the genetic variants is crucial in clinical management. We report the fifth case of a patient with unclassified CDAs, after genetic study, with CDA type IV.
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Affiliation(s)
- Silvia de-la-Iglesia-Iñigo
- Servicio de Hematología y Hemoterapia Hospital Universitario de Gran Canaria Doctor Negrín Las Palmas de Gran Canaria España
| | | | - Angelina Lemes-Castellano
- Servicio de Hematología y Hemoterapia Hospital Universitario de Gran Canaria Doctor Negrín Las Palmas de Gran Canaria España
| | - Teresa Molero-Labarta
- Servicio de Hematología y Hemoterapia Hospital Universitario de Gran Canaria Doctor Negrín Las Palmas de Gran Canaria España
| | - Manuel Méndez
- Centro de Investigación Instituto de Investigación Hospital 12 de Octubre Madrid España
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30
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Gallagher PG, Maksimova Y, Schulz VP, Forget BG. Mutation in a Highly Conserved COOH-Terminal Residue of Krüppel-Like Factor 1 Associated with Elevated Hb F in a Compound Heterozygous β-Thalassemia Patient with a Nontransfusion-Dependent Thalassemia Phenotype. Hemoglobin 2016; 40:361-364. [PMID: 27821015 DOI: 10.1080/03630269.2016.1214921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We present a patient with a compound heterozygosity codon 39 (C > T) (β0) [or β39(C5)Gln→Stop (G39X); CAG > TAG; HBB: c.118C > T] and -87 (C > T) (β+) (HBB: c.-137C > T) β-globin mutations, a non transfusion-dependent thalassemia phenotype and 97.0% fetal hemoglobin. A novel heterozygous mutation was identified in a highly conserved residue in the COOH-terminus of the Krüppel-like factor 1, R360H, that likely altered DNA-binding and impaired transactivation.
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Affiliation(s)
- Patrick G Gallagher
- a Department of Pediatrics , Yale University School of Medicine , New Haven , CT , USA.,b Departments of Pathology and Genetics , University School of Medicine , New Haven , CT , USA
| | - Yelena Maksimova
- a Department of Pediatrics , Yale University School of Medicine , New Haven , CT , USA
| | - Vincent P Schulz
- a Department of Pediatrics , Yale University School of Medicine , New Haven , CT , USA
| | - Bernard G Forget
- c Department of Internal Medicine , Yale School of Medicine , New Haven , CT , USA
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31
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Tepakhan W, Yamsri S, Sanchaisuriya K, Fucharoen G, Xu X, Fucharoen S. Nine known and five novel mutations in the erythroid transcription factor KLF1 gene and phenotypic expression of fetal hemoglobin in hemoglobin E disorder. Blood Cells Mol Dis 2016; 59:85-91. [DOI: 10.1016/j.bcmd.2016.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 04/24/2016] [Accepted: 04/24/2016] [Indexed: 01/26/2023]
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32
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Paglietti ME, Satta S, Sollaino MC, Barella S, Ventrella A, Desogus MF, Demartis FR, Manunza L, Origa R. The Problem of Borderline Hemoglobin A2 Levels in the Screening for β-Thalassemia Carriers in Sardinia. Acta Haematol 2016; 135:193-9. [PMID: 26794457 DOI: 10.1159/000442194] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/04/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND The increase in HbA2 is the most important parameter for the identification of thalassemia carriers. However, in routine screening for hemoglobinopathies, some cases are difficult to classify because the level of HbA2 is not typically elevated. In this work, we report the results of a molecular investigation on a cohort of subjects with borderline HbA2. METHODS All subjects with a β-thalassemia carrier partner and a borderline percentage level of HbA2 were investigated for the presence of a pathological mutation in the β-globin gene. All negative subjects were screened for both the KLF1 mutation and the presence of ααα/ or αααα/ alleles. The subjects with reduced MCV and/or MCH were also screened for deletional and nondeletional α-globin gene defects. RESULTS Various β-globin mutations and KLF1 gene defects are the most common genetic determinants responsible for this phenotype in our population. CONCLUSION KLF1 mutations are important in a screening program for hemoglobinopathies. An increase in HbF in association with borderline HbA2 levels is a useful but not exclusive marker that suggests the investigation of this gene. On the basis of our findings, we are able to suggest the molecular procedure to use in a population characterized by a high prevalence of thalassemia carriers.
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Affiliation(s)
- Maria Elisabetta Paglietti
- Dipartimento di Sanitx00E0; Pubblica, Medicina Clinica e Molecolare, Universitx00E0; degli Studi di Cagliari, Ospedale Microcitemico, Cagliari, Italy
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Gambale A, Iolascon A, Andolfo I, Russo R. Diagnosis and management of congenital dyserythropoietic anemias. Expert Rev Hematol 2016; 9:283-96. [PMID: 26653117 DOI: 10.1586/17474086.2016.1131608] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Congenital dyserythropoietic anemias (CDAs) are inherited disorders hallmarked by chronic hyporegenerative anemia, relative reticulocytopenia, hemolytic component and iron overload. They represent a subtype of the inherited bone marrow failure syndromes, characterized by impaired differentiation and proliferation of the erythroid lineage. Three classical types were defined by marrow morphology, even if the most recent classification recognized six different genetic types. The pathomechanisms of CDAs are different, but all seem to involve the regulation of DNA replication and cell division. CDAs are often misdiagnosed, since either morphological abnormalities or clinical features can be commonly identified in other clinically-related anemias. However, differential diagnosis is essential for guiding both follow up and management of the patients.
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Affiliation(s)
- Antonella Gambale
- a Dipartimento di Medicina Molecolare e Biotecnologie Mediche , Università degli Studi di Napoli Federico II , Napoli , Italy.,b CEINGE Biotecnologie Avanzate , Napoli , Italy
| | - Achille Iolascon
- a Dipartimento di Medicina Molecolare e Biotecnologie Mediche , Università degli Studi di Napoli Federico II , Napoli , Italy.,b CEINGE Biotecnologie Avanzate , Napoli , Italy
| | - Immacolata Andolfo
- a Dipartimento di Medicina Molecolare e Biotecnologie Mediche , Università degli Studi di Napoli Federico II , Napoli , Italy.,b CEINGE Biotecnologie Avanzate , Napoli , Italy
| | - Roberta Russo
- a Dipartimento di Medicina Molecolare e Biotecnologie Mediche , Università degli Studi di Napoli Federico II , Napoli , Italy.,b CEINGE Biotecnologie Avanzate , Napoli , Italy
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