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Vadolas J, Nualkaew T, Voon HPJ, Vilcassim S, Grigoriadis G. Interplay between α-thalassemia and β-hemoglobinopathies: Translating genotype-phenotype relationships into therapies. Hemasphere 2024; 8:e78. [PMID: 38752170 PMCID: PMC11094674 DOI: 10.1002/hem3.78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/22/2024] [Accepted: 04/11/2024] [Indexed: 05/18/2024] Open
Abstract
α-Thalassemia represents one of the most important genetic modulators of β-hemoglobinopathies. During this last decade, the ongoing interest in characterizing genotype-phenotype relationships has yielded incredible insights into α-globin gene regulation and its impact on β-hemoglobinopathies. In this review, we provide a holistic update on α-globin gene expression stemming from DNA to RNA to protein, as well as epigenetic mechanisms that can impact gene expression and potentially influence phenotypic outcomes. Here, we highlight defined α-globin targeted strategies and rationalize the use of distinct molecular targets based on the restoration of balanced α/β-like globin chain synthesis. Considering the therapies that either increase β-globin synthesis or reactivate γ-globin gene expression, the modulation of α-globin chains as a disease modifier for β-hemoglobinopathies still remains largely uncharted in clinical studies.
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Affiliation(s)
- Jim Vadolas
- Centre for Cancer ResearchHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Molecular and Translational SciencesMonash UniversityClaytonVictoriaAustralia
| | - Tiwaporn Nualkaew
- Centre for Cancer ResearchHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Present address:
Department of Medical Technology, School of Allied Health SciencesWalailak UniversityNakhon Si ThammaratThailand
| | - Hsiao P. J. Voon
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery InstituteMonash UniversityClaytonVictoriaAustralia
| | - Shahla Vilcassim
- Centre for Cancer ResearchHudson Institute of Medical ResearchClaytonVictoriaAustralia
- School of Clinical Sciences at Monash HealthMonash UniversityClaytonAustralia
| | - George Grigoriadis
- Centre for Cancer ResearchHudson Institute of Medical ResearchClaytonVictoriaAustralia
- School of Clinical Sciences at Monash HealthMonash UniversityClaytonAustralia
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2
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Application of Weighted Gene Coexpression Network Analysis to Identify Key Modules and Hub Genes in Systemic Juvenile Idiopathic Arthritis. BIOMED RESEARCH INTERNATIONAL 2021; 2021:9957569. [PMID: 34435051 PMCID: PMC8382540 DOI: 10.1155/2021/9957569] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/22/2021] [Indexed: 12/14/2022]
Abstract
Systemic juvenile idiopathic arthritis (sJIA) is a severe autoinflammatory disorder with a still not clearly defined molecular mechanism. To better understand the disease, we used scattered datasets from public domains and performed a weighted gene coexpression network analysis (WGCNA) to identify key modules and hub genes underlying sJIA pathogenesis. Two gene expression datasets, GSE7753 and GSE13501, were used to construct the WGCNA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to the genes and hub genes in the sJIA modules. Cytoscape was used to screen and visualize the hub genes. We further compared the hub genes with the genome-wide association study (GWAS) genes and used a consensus WGCNA to verify that our conclusions were conservative and reproducible across multiple independent datasets. A total of 5,414 genes were obtained for WGCNA, from which highly correlated genes were divided into 17 modules. The red module demonstrated the highest correlation with the sJIA module (r = 0.8, p = 3e−29), whereas the green-yellow module was found to be closely related to the non-sJIA module (r = 0.62, p = 1e−14). Functional enrichment analysis demonstrated that the red module was mostly enriched in the activation of immune responses, infection, nucleosomes, and erythrocytes, and the green-yellow module was mostly enriched in immune responses and inflammation. Additionally, the hub genes in the red module were highly enriched in erythrocyte differentiation, including ALAS2, AHSP, TRIM10, TRIM58, and KLF1. The hub genes from the green-yellow module were mainly associated with immune responses, as exemplified by the genes KLRB1, KLRF1, CD160, and KIRs. We identified sJIA-related modules and several hub genes that might be associated with the development of sJIA. Particularly, the modules may help understand the mechanisms of sJIA, and the hub genes may become biomarkers and therapeutic targets of sJIA in the future.
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3
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Hu Y, Stilp AM, McHugh CP, Rao S, Jain D, Zheng X, Lane J, Méric de Bellefon S, Raffield LM, Chen MH, Yanek LR, Wheeler M, Yao Y, Ren C, Broome J, Moon JY, de Vries PS, Hobbs BD, Sun Q, Surendran P, Brody JA, Blackwell TW, Choquet H, Ryan K, Duggirala R, Heard-Costa N, Wang Z, Chami N, Preuss MH, Min N, Ekunwe L, Lange LA, Cushman M, Faraday N, Curran JE, Almasy L, Kundu K, Smith AV, Gabriel S, Rotter JI, Fornage M, Lloyd-Jones DM, Vasan RS, Smith NL, North KE, Boerwinkle E, Becker LC, Lewis JP, Abecasis GR, Hou L, O'Connell JR, Morrison AC, Beaty TH, Kaplan R, Correa A, Blangero J, Jorgenson E, Psaty BM, Kooperberg C, Walton RT, Kleinstiver BP, Tang H, Loos RJF, Soranzo N, Butterworth AS, Nickerson D, Rich SS, Mitchell BD, Johnson AD, Auer PL, Li Y, Mathias RA, Lettre G, Pankratz N, Laurie CC, Laurie CA, Bauer DE, Conomos MP, Reiner AP. Whole-genome sequencing association analysis of quantitative red blood cell phenotypes: The NHLBI TOPMed program. Am J Hum Genet 2021; 108:874-893. [PMID: 33887194 DOI: 10.1016/j.ajhg.2021.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/30/2021] [Indexed: 02/06/2023] Open
Abstract
Whole-genome sequencing (WGS), a powerful tool for detecting novel coding and non-coding disease-causing variants, has largely been applied to clinical diagnosis of inherited disorders. Here we leveraged WGS data in up to 62,653 ethnically diverse participants from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program and assessed statistical association of variants with seven red blood cell (RBC) quantitative traits. We discovered 14 single variant-RBC trait associations at 12 genomic loci, which have not been reported previously. Several of the RBC trait-variant associations (RPN1, ELL2, MIDN, HBB, HBA1, PIEZO1, and G6PD) were replicated in independent GWAS datasets imputed to the TOPMed reference panel. Most of these discovered variants are rare/low frequency, and several are observed disproportionately among non-European Ancestry (African, Hispanic/Latino, or East Asian) populations. We identified a 3 bp indel p.Lys2169del (g.88717175_88717177TCT[4]) (common only in the Ashkenazi Jewish population) of PIEZO1, a gene responsible for the Mendelian red cell disorder hereditary xerocytosis (MIM: 194380), associated with higher mean corpuscular hemoglobin concentration (MCHC). In stepwise conditional analysis and in gene-based rare variant aggregated association analysis, we identified several of the variants in HBB, HBA1, TMPRSS6, and G6PD that represent the carrier state for known coding, promoter, or splice site loss-of-function variants that cause inherited RBC disorders. Finally, we applied base and nuclease editing to demonstrate that the sentinel variant rs112097551 (nearest gene RPN1) acts through a cis-regulatory element that exerts long-range control of the gene RUVBL1 which is essential for hematopoiesis. Together, these results demonstrate the utility of WGS in ethnically diverse population-based samples and gene editing for expanding knowledge of the genetic architecture of quantitative hematologic traits and suggest a continuum between complex trait and Mendelian red cell disorders.
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Affiliation(s)
- Yao Hu
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98105, USA
| | - Adrienne M Stilp
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Caitlin P McHugh
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Shuquan Rao
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Deepti Jain
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Xiuwen Zheng
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - John Lane
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | | | - Laura M Raffield
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ming-Huei Chen
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA
| | - Lisa R Yanek
- Division of General Internal Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Marsha Wheeler
- Department of Genome Sciences, University of Washington, Seattle, WA 98105, USA
| | - Yao Yao
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Chunyan Ren
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Jai Broome
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Jee-Young Moon
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Paul S de Vries
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Brian D Hobbs
- Channing Division of Network Medicine and Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Quan Sun
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Praveen Surendran
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge CB1 8RN, UK; Rutherford Fund Fellow, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK
| | - Jennifer A Brody
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA 98105, USA
| | - Thomas W Blackwell
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California, Oakland, CA 94601, USA
| | - Kathleen Ryan
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ravindranath Duggirala
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Nancy Heard-Costa
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA; Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Zhe Wang
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nathalie Chami
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael H Preuss
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nancy Min
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Lynette Ekunwe
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Leslie A Lange
- Division of Biomedical Informatics and Personalized Medicine, School of Medicine University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mary Cushman
- Department of Medicine, Larner College of Medicine at the University of Vermont, Burlington, VT 05405, USA
| | - Nauder Faraday
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joanne E Curran
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Laura Almasy
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia and Department of Genetics University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kousik Kundu
- Department of Human Genetics, Wellcome Sanger Institute, Hinxton CB10 1SA, UK; Department of Haematology, University of Cambridge, Cambridge CB2 0PT, UK
| | - Albert V Smith
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | | | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Myriam Fornage
- University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | | | - Ramachandran S Vasan
- National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA; Departments of Cardiology and Preventive Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Nicholas L Smith
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA; Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, WA 98105, USA; Seattle Epidemiologic Research and Information Center, Department of Veterans Affairs Office of Research and Development, Seattle, WA 98105, USA
| | - Kari E North
- Department of Epidemiology, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Eric Boerwinkle
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Lewis C Becker
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joshua P Lewis
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Goncalo R Abecasis
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | - Lifang Hou
- Northwestern University, Chicago, IL 60208, USA
| | - Jeffrey R O'Connell
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Alanna C Morrison
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Terri H Beaty
- School of Public Health, John Hopkins University, Baltimore, MD 21205, USA
| | - Robert Kaplan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Adolfo Correa
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - John Blangero
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Eric Jorgenson
- Division of Research, Kaiser Permanente Northern California, Oakland, CA 94601, USA
| | - Bruce M Psaty
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA; Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98105, USA
| | - Charles Kooperberg
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98105, USA
| | - Russell T Walton
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Hua Tang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ruth J F Loos
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nicole Soranzo
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Department of Human Genetics, Wellcome Sanger Institute, Hinxton CB10 1SA, UK; Department of Haematology, University of Cambridge, Cambridge CB2 0PT, UK; National Institute for Health Research Blood and Transplant Research Unit in Donor Health and Genomics, University of Cambridge, Cambridge CB1 8RN, UK
| | - Adam S Butterworth
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge CB1 8RN, UK; National Institute for Health Research Blood and Transplant Research Unit in Donor Health and Genomics, University of Cambridge, Cambridge CB1 8RN, UK; National Institute for Health Research Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge CB1 8RN, UK
| | - Debbie Nickerson
- Department of Genome Sciences, University of Washington, Seattle, WA 98105, USA
| | - Stephen S Rich
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Braxton D Mitchell
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Andrew D Johnson
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA
| | - Paul L Auer
- Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, WI 53205, USA
| | - Yun Li
- Departments of Biostatistics, Genetics, Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rasika A Mathias
- Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MA 21205, USA
| | - Guillaume Lettre
- Montreal Heart Institute, Montréal, QC H1T 1C8, Canada; Faculté de Médecine, Université de Montréal, Montréal, QC H1T 1C8, Canada
| | - Nathan Pankratz
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Cathy C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Cecelia A Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Daniel E Bauer
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Matthew P Conomos
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Alexander P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA.
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Qin D, Du L, Wang J, Yao C, Guo H, Yuan T, Liang J, Yin A. Compound heterozygosity for hemoglobin variant Hb-Broomhill and the Southeast Asian α-thalassemia deletion does not worsen outcome: a case report of two unrelated patients. J Int Med Res 2020; 48:300060520967825. [PMID: 33213249 PMCID: PMC7683915 DOI: 10.1177/0300060520967825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We report two unrelated cases of compound heterozygosity for hemoglobin (Hb) variant Broomhill and the Southeast Asian (- - SEA/) α-thalassemia deletion, whose clinical features and laboratory findings have never been reported. Hematological analyses revealed abnormal values for both cases as α-thalassemia traits, and capillary electrophoresis suggested an abnormal peak that was incompletely separated from the Hb A peak. A suspension array system and Sanger sequencing were used to characterize the genotypes. Sanger sequencing confirmed the presence of Hb Broomhill [α114(GH2)Pro→Ala; HBA1: c.343C>G]. Eventually, both cases were accurately diagnosed as compound heterozygotes for Hb Broomhill and the (- - SEA/) α-thalassemia deletion, which is the first known report of these variants. This information will be useful when providing appropriate genetic counselling and prenatal diagnosis.
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Affiliation(s)
- Danqing Qin
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Li Du
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Jicheng Wang
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Cuize Yao
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Hao Guo
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Tenglong Yuan
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Jie Liang
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
| | - Aihua Yin
- Medical Genetic Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China.,Thalassemia Diagnosis Center, Guangdong Women and Children Hospital, Guangzhou, Guangdong, China
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5
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Cardiero G, Musollino G, Friscia MG, Testa R, Virruso L, Di Girgenti C, Caldora M, Colella Bisogno R, Gaudiano C, Manco G, Lacerra G. Effect of Mutations on mRNA and Globin Stability: The Cases of Hb Bernalda/Groene Hart and Hb Southern Italy. Genes (Basel) 2020; 11:genes11080870. [PMID: 32751969 PMCID: PMC7466077 DOI: 10.3390/genes11080870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/27/2020] [Accepted: 07/29/2020] [Indexed: 11/16/2022] Open
Abstract
We identified two unstable variants in the third exon of α-globin genes: Hb Bernalda/Groene Hart (HBA1:c.358C>T), and Hb Caserta (HBA2:c.79G>A) in cis to Hb Sun Prairie (HBA2:c.391G>C), also named Hb Southern Italy. These mutations occurred in the H helix of the α-globin that is involved in heme contacting, specific recognition of α-hemoglobin-stabilizing protein (AHSP), and α1β1 interactions. The carriers showed α-thalassemia phenotype, but one also jaundice and cholelithiasis. Molecular identification of clusters of families in Southern Italy encouraged molecular characterization of mRNA, globin chain analyses, molecular modeling studies, and comparison with globin variants to understand the mechanisms causing the α-thalassemia phenotype. A normal amount of Hb Bernalda/Groene Hart mRNA were found, and molecular modeling highlighted additional H bonds with AHSP. For Hb Southern Italy, showing an unexpected α/β biosynthetic ratio typical of the β-thalassemia type, two different molecular mechanisms were shown: Reduction of the variant mRNA, likely due to the No-Go Decay for the presence of unused triplet ACG at cod 26, and protein instability due to the impairment of AHSP interaction. The UDP glucuronosyltransferase 1A (UGT1A1) genotyping was conclusive in the case of jaundice and cholelithiasis. Multiple approaches are needed to properly identify the mechanisms leading to unstable variants and the effect of a mutation.
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Affiliation(s)
- Giovanna Cardiero
- Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, (IGB-ABT, CNR), National Research Council, 80131 Naples, Italy; (G.C.); (G.M.)
| | - Gennaro Musollino
- Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, (IGB-ABT, CNR), National Research Council, 80131 Naples, Italy; (G.C.); (G.M.)
| | - Maria Grazia Friscia
- Azienda Ospedaliera Ospedali Civili Riuniti, Centro Trasfusionale e di Microcitemia, 92019 Sciacca, Italy;
| | - Rosario Testa
- Azienda Ospedaliero-Universitaria “Policlinico-Vittorio Emanuele”, Servizio di Talassemia ed Emoglobinopatie, 95123 Catania, Italy;
| | - Lucrezia Virruso
- ARNAS P.O. Civico e Di Cristina Benfratelli, U.O.s.d. Lab. Spec. Genetica Molecolare, 90127 Palermo, Italy; (L.V.); (C.D.G.)
| | - Caterina Di Girgenti
- ARNAS P.O. Civico e Di Cristina Benfratelli, U.O.s.d. Lab. Spec. Genetica Molecolare, 90127 Palermo, Italy; (L.V.); (C.D.G.)
| | | | - Rosario Colella Bisogno
- Azienda Ospedaliera Universitaria OO. RR. San Giovanni di Dio e Ruggi D’Aragona, Medicina Trasfusionale, 84131 Salerno, Italy;
| | - Carlo Gaudiano
- P.O. Madonna delle Grazie, Centro per la Lotta Contro le Microcitemie, ASL 4, 75100 Matera, Italy;
| | - Giuseppe Manco
- Institute of Biochemistry and Cell Biology (IBBC, CNR), National Research Council, 80131 Naples, Italy;
| | - Giuseppina Lacerra
- Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, (IGB-ABT, CNR), National Research Council, 80131 Naples, Italy; (G.C.); (G.M.)
- Correspondence:
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6
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The Interplay between Molten Globules and Heme Disassociation Defines Human Hemoglobin Disassembly. Biophys J 2020; 118:1381-1400. [PMID: 32075750 DOI: 10.1016/j.bpj.2020.01.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/22/2020] [Accepted: 01/27/2020] [Indexed: 12/12/2022] Open
Abstract
Hemoglobin functions as a tetrameric oxygen transport protein, with each subunit containing a heme cofactor. Its denaturation, either in vivo or in vitro, involves autoxidation to methemoglobin, followed by cofactor loss and globin unfolding. We have proposed a global disassembly scheme for human methemoglobin, linking hemin (ferric protoporphyrin IX) disassociation and apoprotein unfolding pathways. The model is based on the evaluation of circular dichroism and visible absorbance measurements of guanidine-hydrochloride-induced disassembly of methemoglobin and previous measurements of apohemoglobin unfolding. The populations of holointermediates and equilibrium disassembly parameters were estimated quantitatively for adult and fetal hemoglobins. The key stages are characterized by hexacoordinated hemichrome intermediates, which are important for preventing hemin disassociation from partially unfolded, molten globular species during early disassembly and late-stage assembly events. Both unfolding experiments and independent small angle x-ray scattering measurements demonstrate that heme disassociation leads to the loss of tetrameric structural integrity. Our model predicts that after autoxidation, dimeric and monomeric hemichrome intermediates occur along the disassembly pathway inside red cells, where the hemoglobin concentration is very high. This prediction suggests why misassembled hemoglobins often get trapped as hemichromes that accumulate into insoluble Heinz bodies in the red cells of patients with unstable hemoglobinopathies. These Heinz bodies become deposited on the cell membranes and can lead to hemolysis. Alternatively, when acellular hemoglobin is diluted into blood plasma after red cell lysis, the disassembly pathway appears to be dominated by early hemin disassociation events, which leads to the generation of higher fractions of unfolded apo subunits and free hemin, which are known to damage the integrity of blood vessel walls. Thus, our model provides explanations of the pathophysiology of hemoglobinopathies and other disease states associated with unstable globins and red cell lysis and also insights into the factors governing hemoglobin assembly during erythropoiesis.
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Klei TRL, Kheradmand Kia S, Veldthuis M, Dehbozorgian J, Karimi M, Geissler J, Sellink E, Thiel-Valkhof M, Burger P, van Alphen F, Meijer AB, van Bruggen R, van Zwieten R. A Homozygous Mutation on the HBA1 Gene Coding for Hb Charlieu (HBA1: c.320T>C) Together with β-Thalassemia Trait Results in Severe Hemolytic Anemia. Hemoglobin 2019; 43:77-82. [PMID: 31190578 DOI: 10.1080/03630269.2019.1601107] [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: 10/26/2022]
Abstract
A 4-year-old boy, a β-thalassemia (β-thal) carrier, with an unexplained severe chronic microcytic anemia was referred to us. Sequencing of the α-globin genes revealed a Hb Charlieu [α106(G13)Leu→Pro, HBA1: c.320T>C, p.Leu107Pro] mutation present on both HBA1 genes. Quantitative polymerase chain reaction (qPCR) confirmed αCharlieu mRNA in the proband and his parents, showing that the mutation does not affect mRNA stability. However, we were unable to detect the Hb Charlieu protein by capillary electrophoresis (CE), reverse phase electrophoresis, cation exchange electrophoresis or isoelectric focusing. Mass spectrometry (MS) allowed us to confirm the presence of the Hb Charlieu peptide in erythrocyte progenitors. These findings suggest that the mutation affects the stability of αCharlieu. As hemoglobin (Hb) heat stability tests showed no abnormalities in erythrocytes, we speculated that αCharlieu is already degraded during red blood cell (RBC) development. The clinical severity in the proband and the presence of new methylene blue-stained aggregates in his reticulocytes indicates that incorporation of αCharlieu destabilizes Hb. This, combined with an excess of unstable free α-globins as the result of β-thal minor, results in severely impaired erythropoiesis and, as a consequence, severe and chronic microcytic anemia in the proband.
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Affiliation(s)
- Thomas R L Klei
- a Department of Blood Cell Research , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , the Netherlands
| | - Sima Kheradmand Kia
- b Laboratory for Red Blood Cell Diagostics , Sanquin , Amsterdam , The Netherlands.,c Department of Hematology , PeyvandLab Complex , Shiraz , Iran
| | - Martijn Veldthuis
- b Laboratory for Red Blood Cell Diagostics , Sanquin , Amsterdam , The Netherlands
| | | | - Mehran Karimi
- d Hematology Research Center, Shiraz University of Medical Sciences , Shiraz , Iran
| | - Judy Geissler
- a Department of Blood Cell Research , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , the Netherlands
| | - Erica Sellink
- e Department of Hematopoiesis , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , The Netherlands
| | - Marijke Thiel-Valkhof
- e Department of Hematopoiesis , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , The Netherlands
| | - Patrick Burger
- e Department of Hematopoiesis , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , The Netherlands
| | - Floris van Alphen
- f Department of Molecular and Cellular Hemostasis , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , The Netherlands
| | - Alexander B Meijer
- f Department of Molecular and Cellular Hemostasis , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , The Netherlands.,g Department of Biomolecular Mass Spectrometry and Proteomics , Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University , Utrecht 3584 CS , The Netherlands
| | - Robin van Bruggen
- a Department of Blood Cell Research , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , the Netherlands
| | - Rob van Zwieten
- a Department of Blood Cell Research , Sanquin Research and Landsteiner Laboratory, University of Amsterdam , Amsterdam , the Netherlands.,b Laboratory for Red Blood Cell Diagostics , Sanquin , Amsterdam , The Netherlands
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PG545 treatment reduces RRV-induced elevations of AST, ALT with secondary lymphoid organ alterations in C57BL/6 mice. PLoS One 2019; 14:e0217998. [PMID: 31170255 PMCID: PMC6553857 DOI: 10.1371/journal.pone.0217998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/22/2019] [Indexed: 01/04/2023] Open
Abstract
Recently the anti-viral effects of prophylactic treatment with the low-molecular-weight heparan sulfate mimetic PG545 in Ross River virus (RRV) infected mice were reported. We further investigated the related, transient pathophysiology of PG545 drug treatment in RRV-infected and mock-infected PG545-treated mice. PG545 treatment resulted in mild lethargy and piloerection, on days after the drug administration. Mice were treated with two or three doses of PG545 within a ten-day period and were subsequently culled at peak disease or at disease resolution. The treatment responses of the spleen and liver were assessed through histology, flow cytometry, gene arrays and serum biochemistry. Microscopy showed an expanded red pulp in the spleen following either two or three treatments with PG545. The red pulp expansion was further demonstrated by the proliferation of megakaryocytes and erythrocyte precursors within the spleen. In addition, flow cytometry and gene array analyses revealed a reduction of lymphocytes within the spleens of PG545-treated mice. Previously unreported, RRV-induced elevations of aspartate aminotransferase (AST) and alanine transaminase (ALT) enzymes and creatinine were also noted in the RRV-infected mice. However, PG545 only reduced AST and ALT levels but not the creatinine levels in infected mice during treatment. Mice treated with three doses of PG545 also showed hepatosplenomegaly and anaemia, which were reversed upon discontinuation of the treatment. In summary, this study demonstrates that dose and frequency related haemopoietic pathophysiology such as hepatosplenomegaly and anaemia, occurred in C57BL/6 mice treated with PG545. However, this effect was reversible once drug administration is terminated.
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Scheps KG, Varela V, Targovnik HM. The Chaperones Involved in Hemoglobin Synthesis Take the Spotlight: Analysis of AHSP in the Argentinean Population and Review of the Literature. Hemoglobin 2018; 42:310-314. [PMID: 30558442 DOI: 10.1080/03630269.2018.1544145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hemoglobin (Hb) synthesis is a complex, well-coordinated process that requires molecular chaperones. These intervene in different steps: regulating epigenetic mechanisms necessary for the adequate expression of the α- and β-globin clusters, binding the nascent peptides and helping them acquire their native structure, preventing oxidative damage by free globin chains and preventing the cleavage of essential erythroid transcription factors. This study analyzed the distribution of the single nucleotide polymorphism (SNP) rs4296276 in intron 1 of the α-globin chaperone α Hb-stabilizing protein (AHSP) in the Argentinean population. The risk allele was found in thalassemia patients who exhibited more severe phenotypes than expected. Future studies may help establish the role of these chaperones as modifiers in pathological states with globin chain imbalance, such as thalassemia.
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Affiliation(s)
- Karen G Scheps
- a Departamento de Microbiología , Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Inmunología, Biotecnología y Genética/Cátedra de Genética , Buenos Aires , Argentina.,b Instituto de Inmunología, Genética y Metabolismo (INIGEM) , CONICET-Universidad de Buenos Aires , Buenos Aires , Argentina
| | - Viviana Varela
- a Departamento de Microbiología , Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Inmunología, Biotecnología y Genética/Cátedra de Genética , Buenos Aires , Argentina.,b Instituto de Inmunología, Genética y Metabolismo (INIGEM) , CONICET-Universidad de Buenos Aires , Buenos Aires , Argentina
| | - Héctor M Targovnik
- a Departamento de Microbiología , Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Inmunología, Biotecnología y Genética/Cátedra de Genética , Buenos Aires , Argentina.,b Instituto de Inmunología, Genética y Metabolismo (INIGEM) , CONICET-Universidad de Buenos Aires , Buenos Aires , Argentina
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Xu AP, Li J, Chen WD, Zhou Y, Ji L. Hb Hubei [α114(GH2)Pro→His, HBA1: c.344C>A]: A Novel Hemoglobin Variant of the α1-Globin Chain. Hemoglobin 2018; 42:206-208. [PMID: 30277418 DOI: 10.1080/03630269.2018.1502197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We report here a novel α1-globin chain variant, Hb Hubei [α114(GH2)Pro→His, HBA1: c.344C>A], in a Chinese individual. The proband, a 28-year-old Chinese female, was discovered following routine Hb A1c analysis using cation exchange high performance liquid chromatography (HPLC). Sanger sequencing revealed a novel missense mutation, HBA1: c.344C>A (CCC>CAC), in exon 2 of the α1-globin gene. The mutation caused a transition of proline to histidine at position α114(GH2) on the α1-globin chain. This new variant was named Hb Hubei after the geographic origin of the proband.
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Affiliation(s)
- An-Ping Xu
- a Department of Clinical Medical Laboratory , Peking University Shenzhen Hospital , Shenzhen , Guangdong Province , People's Republic of China
| | - Jie Li
- a Department of Clinical Medical Laboratory , Peking University Shenzhen Hospital , Shenzhen , Guangdong Province , People's Republic of China
| | - Wei-Dong Chen
- a Department of Clinical Medical Laboratory , Peking University Shenzhen Hospital , Shenzhen , Guangdong Province , People's Republic of China
| | - Yu Zhou
- a Department of Clinical Medical Laboratory , Peking University Shenzhen Hospital , Shenzhen , Guangdong Province , People's Republic of China
| | - Ling Ji
- a Department of Clinical Medical Laboratory , Peking University Shenzhen Hospital , Shenzhen , Guangdong Province , People's Republic of China
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Van de Water N, Tan T, Crowley M, Kerr R, Browett P. Novel α-Globin Splice Site Mutation (HBA2: c.96-5C>A) in Combination with Three-Gene Deletion Hb H Disease. Hemoglobin 2018; 42:122-125. [PMID: 30200833 DOI: 10.1080/03630269.2018.1487307] [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: 10/28/2022]
Abstract
The choice of acceptor splice site during exon-exon splicing by the spliceosome is determined by a variety of factors. We report here a family with a novel acceptor splice site variant within intron 1 of the α-globin gene that provides some in vivo insight into the rules governing RNA splicing in homo sapiens. A 2-year-old female with Hb H disease, was found to have not only three α-globin genes deleted (- -FIL/-α3.7) but also a HBA2: c.96-5C>A variant on her remaining α-globin gene. The HBA2: c.96-5C>A variant was in cis with -α3.7 and mRNA studies indicate that this variant creates a new acceptor splice site which is used in approximately 35.0% of α-globin mRNA transcripts. The reduced levels of normal mRNA transcript predicts a more severe Hb H disease than expected for the three-gene deletion Hb H disease with a phenotype similar to nondeletional Hb H disease. We propose that this variant be called Hb Beach Haven (HBA2: c.96-5C>A).
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Affiliation(s)
- Neil Van de Water
- a Diagnostic Genetics Department , LabPlus, Auckland City Hospital , Auckland , New Zealand
| | - Tina Tan
- a Diagnostic Genetics Department , LabPlus, Auckland City Hospital , Auckland , New Zealand
| | - Megan Crowley
- a Diagnostic Genetics Department , LabPlus, Auckland City Hospital , Auckland , New Zealand
| | - Romy Kerr
- b Genetic Health Service , Auckland City Hospital , New Zealand
| | - Peter Browett
- a Diagnostic Genetics Department , LabPlus, Auckland City Hospital , Auckland , New Zealand.,c Department of Molecular Medicine & Pathology , University of Auckland , Auckland , New Zealand
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Yanagitani K, Juszkiewicz S, Hegde RS. UBE2O is a quality control factor for orphans of multiprotein complexes. Science 2018; 357:472-475. [PMID: 28774922 DOI: 10.1126/science.aan0178] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/08/2017] [Indexed: 01/02/2023]
Abstract
Many nascent proteins are assembled into multiprotein complexes of defined stoichiometry. Imbalances in the synthesis of individual subunits result in orphans. How orphans are selectively eliminated to maintain protein homeostasis is poorly understood. Here, we found that the conserved ubiquitin-conjugating enzyme UBE2O directly recognized juxtaposed basic and hydrophobic patches on unassembled proteins to mediate ubiquitination without a separate ubiquitin ligase. In reticulocytes, where UBE2O is highly up-regulated, unassembled α-globin molecules that failed to assemble with β-globin were selectively ubiquitinated by UBE2O. In nonreticulocytes, ribosomal proteins that did not engage nuclear import factors were targets for UBE2O. Thus, UBE2O is a self-contained quality control factor that comprises substrate recognition and ubiquitin transfer activities within a single protein to efficiently target orphans of multiprotein complexes for degradation.
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Affiliation(s)
- Kota Yanagitani
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Szymon Juszkiewicz
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Ramanujan S Hegde
- Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK.
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Handayani NSN, Husna N, Sanka I. α-globin Alteration in α-thalassemia Disorder: Prediction and Interaction Defect. Pak J Biol Sci 2017; 20:343-349. [PMID: 29023066 DOI: 10.3923/pjbs.2017.343.349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND AND OBJECTIVE The α-thalassemia is an inherited blood disorder affecting quality and quantity of hemoglobin. It caused mostly by deletion of one or two α-globin genes and characterized by deficient production of α-globin chain in hemoglobin leading from mild anemia to lethal. The α-globin gene with partial deletion could reduce chain production or produce abnormal chain. Its effect depends on mechanism of chain production affected. This study aimed to analyze the effect of partial deletion in α-globin gene influencing the mechanisms to produce functional α-globin chain in α-thalassemia cases. MATERIALS AND METHOD The three mutant genes from genebank were selected and processed. The analysis performed in deleted sequences determination, mRNA sequences, protein structures and protein chains interaction to form hemoglobin by SWISS MODEL, CHIMERA and SABLE Polyview 2D. RESULTS The result showed 76 amino acids deleted in one mutant α-globin gene (V00516.1). The mutation gave effect in every mechanism of the α-globin chain conformation and production. It affected protein conformation by losing over half the helical chains. It reduced the function completely, in which, disturb hemoglobin A (HbA) production with emergence of β-sheets conformation. CONCLUSION The analysis concluded that the protein produced by the α-globin gene with partial deletion lost its function and unable to form hemoglobin.
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Affiliation(s)
- Niken Satuti Nur Handayani
- Laboratory of Genetics and Breeding, Faculty of Biology, Universitas Gadjah Mada, Jl. Teknika Selatan, Sekip Utara, Yogyakarta 55281, Indonesia Tel/Fax: +62-274-580839
| | - Nailil Husna
- Laboratory of Genetics and Breeding, Faculty of Biology, Universitas Gadjah Mada, Jl. Teknika Selatan, Sekip Utara, Yogyakarta 55281, Indonesia Tel/Fax: +62-274-580839
| | - Immanuel Sanka
- Laboratory of Genetics and Breeding, Faculty of Biology, Universitas Gadjah Mada, Jl. Teknika Selatan, Sekip Utara, Yogyakarta 55281, Indonesia Tel/Fax: +62-274-580839
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Surapolchai P, Chuansumrit A, Sirachainan N, Kadegasem P, Leung KC, So CC. A molecular study on the role of alpha-hemoglobin-stabilizing protein in hemoglobin H disease. Ann Hematol 2017; 96:1005-1014. [DOI: 10.1007/s00277-017-2978-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 03/09/2017] [Indexed: 11/24/2022]
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15
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Fatunmbi O, Abzalimov RR, Savinov SN, Gershenson A, Kaltashov IA. Interactions of Haptoglobin with Monomeric Globin Species: Insights from Molecular Modeling and Native Electrospray Ionization Mass Spectrometry. Biochemistry 2016; 55:1918-28. [DOI: 10.1021/acs.biochem.5b00807] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ololade Fatunmbi
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Rinat R. Abzalimov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Sergey N. Savinov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Anne Gershenson
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Igor A. Kaltashov
- Department of Chemistry and ‡Department of
Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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Bisconte MG, Caldora M, Musollino G, Cardiero G, Flagiello A, La Porta G, Lagona L, Prezioso R, Qualtieri G, Gaudiano C, Medulla E, Merlino A, Pucci P, Lacerra G. α-Thalassemia associated with hb instability: a tale of two features. the case of Hb Rogliano or α1 Cod 108(G15)Thr→Asn and Hb Policoro or α2 Cod 124(H7)Ser→Pro. PLoS One 2015; 10:e0115738. [PMID: 25730315 PMCID: PMC4346585 DOI: 10.1371/journal.pone.0115738] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/01/2014] [Indexed: 11/28/2022] Open
Abstract
We identified two new variants in the third exon of the α-globin gene in families from southern Italy: the Hb Rogliano, α1 cod108 ACC>AAC or α1[α108(G15)Thr→Asn] and the Hb Policoro, α2 cod124 TCC>CCC or α2[α124(H7)Ser→Pro]. The carriers showed mild α-thalassemia phenotype and abnormal hemoglobin stability features. These mutations occurred in the G and H helices of the α-globin both involved in the specific recognition of AHSP and β1 chain. Molecular characterization of mRNA, globin chain analyses and molecular modelling studies were carried out to highlight the mechanisms causing the α-thalassemia phenotype. The results demonstrated that the α-thalassemia defect associated with the two Hb variants originated by different defects. Hb Rogliano showed an intrinsic instability of the tetramer due to anomalous intra- and inter-chain interactions suggesting that the variant chain is normally synthesized and complexed with AHSP but rapidly degraded because it is unable to form the α1β1 dimers. On the contrary in the case of Hb Policoro two different molecular mechanisms were shown: the reduction of the variant mRNA level by an unclear mechanism and the protein instability due to impairment of AHSP interaction. These data highlighted that multiple approaches, including mRNA quantification, are needed to properly identify the mechanisms leading to the α-thalassemia defect. Elucidation of the specific mechanism leads to the definition of a given phenotype providing important guidance for the diagnosis of unstable variants.
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Affiliation(s)
- Maria Grazia Bisconte
- U.O.S. Microcitemia e patologia del globulo rosso, O.O.C. Ematologia A.O. Cosenza, Italy
| | - Mercedes Caldora
- Laboratorio Specialistico di Ematologia, P.O. San Giovanni Bosco A.S.L. NA1, Napoli, Italy
| | - Gennaro Musollino
- Istituto di Genetica e Biofisica “Adriano Buzzati-Traverso”- Consiglio Nazionale delle Ricerche (CNR), Napoli, Italy
| | - Giovanna Cardiero
- Istituto di Genetica e Biofisica “Adriano Buzzati-Traverso”- Consiglio Nazionale delle Ricerche (CNR), Napoli, Italy
| | - Angela Flagiello
- Dipartimento di Scienze Chimiche and Ceinge Biotecnologie Avanzate, Università degli Studi “Federico II”, Napoli, Italy
| | - Gaetana La Porta
- U.O.S. Microcitemia e patologia del globulo rosso, O.O.C. Ematologia A.O. Cosenza, Italy
| | - Laura Lagona
- U.O.D. di Thalassemia, ARNAS “Garibaldi”, Catania, Italy
| | - Romeo Prezioso
- Istituto di Genetica e Biofisica “Adriano Buzzati-Traverso”- Consiglio Nazionale delle Ricerche (CNR), Napoli, Italy
| | - Gabriele Qualtieri
- U.O.S. Microcitemia e patologia del globulo rosso, O.O.C. Ematologia A.O. Cosenza, Italy
| | - Carlo Gaudiano
- Ospedale Civile, Centro per la lotta contro le Microcitemie, Matera, Italy
| | - Emilia Medulla
- U.O.D. di Thalassemia, ARNAS “Garibaldi”, Catania, Italy
| | - Antonello Merlino
- Dipartimento di Scienze Chimiche, Università degli Studi “Federico II” and Istituto di Biostrutture e Bioimmagini, CNR Napoli, Italy
| | - Piero Pucci
- Dipartimento di Scienze Chimiche and Ceinge Biotecnologie Avanzate, Università degli Studi “Federico II”, Napoli, Italy
| | - Giuseppina Lacerra
- Istituto di Genetica e Biofisica “Adriano Buzzati-Traverso”- Consiglio Nazionale delle Ricerche (CNR), Napoli, Italy
- * E-mail:
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Vasseur C, Baudin-Creuza V. [Role of alpha-hemoglobin molecular chaperone in the hemoglobin formation and clinical expression of some hemoglobinopathies]. Transfus Clin Biol 2015; 22:49-57. [PMID: 25724329 DOI: 10.1016/j.tracli.2015.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 01/21/2015] [Indexed: 10/24/2022]
Abstract
Alpha-hemoglobin stabilizing protein (AHSP), described as a chaperone of alpha-hemoglobin (α-Hb), is synthesized at a high concentration in the erythroid precursors. AHSP specifically recognizes the G and H helices of α-Hb and forms a stable complex with free α-Hb until its association with the partner β-subunits. Unlike the free β-Hb which are soluble and form homologous tetramers, freshly synthesized α-Hb chains are highly unstable molecular species which precipitate and generate reactive oxygen species within the erythrocyte precursors of the bone marrow leading to apoptosis and ineffective erythropoiesis. AHSP protects the free α-Hb chains in maintaining it in the soluble state. In this review, we report data from the literature and our laboratory concerning the key role of AHSP in the biosynthesis of Hb and its possible involvement in some disorders of the red blood cell as well as the hemoglobinopathies and we discuss its use as a prognostic tool in thalassemia syndromes.
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Affiliation(s)
- C Vasseur
- Institut national de la santé et de la recherche médicale (INSERM) U955, équipe 2, université Paris Est Créteil, 5, avenue Gustave-Eiffel, 94000 Créteil, France; Laboratoire d'excellence des globules rouges (GR-EX), 75015 Paris, France
| | - V Baudin-Creuza
- Institut national de la santé et de la recherche médicale (INSERM) U955, équipe 2, université Paris Est Créteil, 5, avenue Gustave-Eiffel, 94000 Créteil, France; Laboratoire d'excellence des globules rouges (GR-EX), 75015 Paris, France.
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Role of α-globin H helix in the building of tetrameric human hemoglobin: interaction with α-hemoglobin stabilizing protein (AHSP) and heme molecule. PLoS One 2014; 9:e111395. [PMID: 25369055 PMCID: PMC4219717 DOI: 10.1371/journal.pone.0111395] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/23/2014] [Indexed: 11/25/2022] Open
Abstract
Alpha-Hemoglobin Stabilizing Protein (AHSP) binds to α-hemoglobin (α-Hb) or α-globin and maintains it in a soluble state until its association with the β-Hb chain partner to form Hb tetramers. AHSP specifically recognizes the G and H helices of α-Hb. To investigate the degree of interaction of the various regions of the α-globin H helix with AHSP, this interface was studied by stepwise elimination of regions of the α-globin H helix: five truncated α-Hbs α-Hb1-138, α-Hb1-134, α-Hb1-126, α-Hb1-123, α-Hb1-117 were co-expressed with AHSP as two glutathione-S-transferase (GST) fusion proteins. SDS-PAGE and Western Blot analysis revealed that the level of expression of each truncated α-Hb was similar to that of the wild type α-Hb except the shortest protein α-Hb1-117 which displayed a decreased expression. While truncated GST-α-Hb1-138 and GST-α-Hb1-134 were normally soluble; the shorter globins GST-α-Hb1-126 and GST-α-Hb1-117 were obtained in very low quantities, and the truncated GST-α-Hb1-123 provided the least material. Absorbance and fluorescence studies of complexes showed that the truncated α-Hb1-134 and shorter forms led to modified absorption spectra together with an increased fluorescence emission. This attests that shortening the H helix leads to a lower affinity of the α-globin for the heme. Upon addition of β-Hb, the increase in fluorescence indicates the replacement of AHSP by β-Hb. The CO binding kinetics of different truncated AHSPWT/α-Hb complexes showed that these Hbs were not functionally normal in terms of the allosteric transition. The N-terminal part of the H helix is primordial for interaction with AHSP and C-terminal part for interaction with heme, both features being required for stability of α-globin chain.
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Andersen Ø, De Rosa MC, Yadav P, Pirolli D, Fernandes JMO, Berg PR, Jentoft S, Andrè C. The conserved Phe GH5 of importance for hemoglobin intersubunit contact is mutated in gadoid fish. BMC Evol Biol 2014; 14:54. [PMID: 24655798 PMCID: PMC3998052 DOI: 10.1186/1471-2148-14-54] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 03/06/2014] [Indexed: 02/04/2023] Open
Abstract
Background Functionality of the tetrameric hemoglobin molecule seems to be determined by a few amino acids located in key positions. Oxygen binding encompasses structural changes at the interfaces between the α1β2 and α2β1 dimers, but also subunit interactions are important for the oxygen binding affinity and stability. The latter packing contacts include the conserved Arg B12 interacting with Phe GH5, which is replaced by Leu and Tyr in the αA and αD chains, respectively, of birds and reptiles. Results Searching all known hemoglobins from a variety of gnathostome species (jawed vertebrates) revealed the almost invariant Arg B12 coded by the AGG triplet positioned at an exon-intron boundary. Rare substitutions of Arg B12 in the gnathostome β globins were found in pig, tree shrew and scaled reptiles. Phe GH5 is also highly conserved in the β globins, except for the Leu replacement in the β1 globin of five marine gadoid species, gilthead seabream and the Comoran coelacanth, while Cys and Ile were found in burbot and yellow croaker, respectively. Atlantic cod β1 globin showed a Leu/Met polymorphism at position GH5 dominated by the Met variant in northwest-Atlantic populations that was rarely found in northeast-Atlantic cod. Site-specific analyses identified six consensus codons under positive selection, including 122β(GH5), indicating that the amino acid changes identified at this position may offer an adaptive advantage. In fact, computational mutation analysis showed that the replacement of Phe GH5 with Leu or Cys decreased the number of van der Waals contacts essentially in the deoxy form that probably causes a slight increase in the oxygen binding affinity. Conclusions The almost invariant Arg B12 and the AGG codon seem to be important for the packing contacts and pre-mRNA processing, respectively, but the rare mutations identified might be beneficial. The Leu122β1(GH5)Met and Met55β1(D6)Val polymorphisms in Atlantic cod hemoglobin modify the intradimer contacts B12-GH5 and H2-D6, while amino acid replacements at these positions in avian hemoglobin seem to be evolutionary adaptive in air-breathing vertebrates. The results support the theory that adaptive changes in hemoglobin functions are caused by a few substitutions at key positions.
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Kiger L, Vasseur C, Domingues-Hamdi E, Truan G, Marden MC, Baudin-Creuza V. Dynamics of α-Hb chain binding to its chaperone AHSP depends on heme coordination and redox state. Biochim Biophys Acta Gen Subj 2014; 1840:277-87. [DOI: 10.1016/j.bbagen.2013.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 09/06/2013] [Accepted: 09/09/2013] [Indexed: 11/27/2022]
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Dickson CF, Rich AM, D'Avigdor WMH, Collins DAT, Lowry JA, Mollan TL, Khandros E, Olson JS, Weiss MJ, Mackay JP, Lay PA, Gell DA. α-Hemoglobin-stabilizing protein (AHSP) perturbs the proximal heme pocket of oxy-α-hemoglobin and weakens the iron-oxygen bond. J Biol Chem 2013; 288:19986-20001. [PMID: 23696640 DOI: 10.1074/jbc.m112.437509] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
α-Hemoglobin (αHb)-stabilizing protein (AHSP) is a molecular chaperone that assists hemoglobin assembly. AHSP induces changes in αHb heme coordination, but how these changes are facilitated by interactions at the αHb·AHSP interface is not well understood. To address this question we have used NMR, x-ray absorption spectroscopy, and ligand binding measurements to probe αHb conformational changes induced by AHSP binding. NMR chemical shift analyses of free CO-αHb and CO-αHb·AHSP indicated that the seven helical elements of the native αHb structure are retained and that the heme Fe(II) remains coordinated to the proximal His-87 side chain. However, chemical shift differences revealed alterations of the F, G, and H helices and the heme pocket of CO-αHb bound to AHSP. Comparisons of iron-ligand geometry using extended x-ray absorption fine structure spectroscopy showed that AHSP binding induces a small 0.03 Å lengthening of the Fe-O2 bond, explaining previous reports that AHSP decreases αHb O2 affinity roughly 4-fold and promotes autooxidation due primarily to a 3-4-fold increase in the rate of O2 dissociation. Pro-30 mutations diminished NMR chemical shift changes in the proximal heme pocket, restored normal O2 dissociation rate and equilibrium constants, and reduced O2-αHb autooxidation rates. Thus, the contacts mediated by Pro-30 in wild-type AHSP promote αHb autooxidation by introducing strain into the proximal heme pocket. As a chaperone, AHSP facilitates rapid assembly of αHb into Hb when βHb is abundant but diverts αHb to a redox resistant holding state when βHb is limiting.
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Affiliation(s)
- Claire F Dickson
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS 7000, Australia
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Thom CS, Dickson CF, Gell DA, Weiss MJ. Hemoglobin variants: biochemical properties and clinical correlates. Cold Spring Harb Perspect Med 2013; 3:a011858. [PMID: 23388674 DOI: 10.1101/cshperspect.a011858] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Diseases affecting hemoglobin synthesis and function are extremely common worldwide. More than 1000 naturally occurring human hemoglobin variants with single amino acid substitutions throughout the molecule have been discovered, mainly through their clinical and/or laboratory manifestations. These variants alter hemoglobin structure and biochemical properties with physiological effects ranging from insignificant to severe. Studies of these mutations in patients and in the laboratory have produced a wealth of information on hemoglobin biochemistry and biology with significant implications for hematology practice. More generally, landmark studies of hemoglobin performed over the past 60 years have established important paradigms for the disciplines of structural biology, genetics, biochemistry, and medicine. Here we review the major classes of hemoglobin variants, emphasizing general concepts and illustrative examples.
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Affiliation(s)
- Christopher S Thom
- Cell and Molecular Biology Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Nienhuis AW, Nathan DG. Pathophysiology and Clinical Manifestations of the β-Thalassemias. Cold Spring Harb Perspect Med 2012; 2:a011726. [PMID: 23209183 DOI: 10.1101/cshperspect.a011726] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The β-thalassemia syndromes reflect deficient or absent β-globin synthesis usually owing to a mutation in the β-globin locus. The relative excess of α-globin results in the formation of insoluble aggregates leading to ineffective erythropoiesis and shortened red cell survival. A relatively high capacity for fetal hemoglobin synthesis is a major genetic modifier of disease severity, with polymorphisms in other genes also having a significant role. Iron overload secondary to enhanced absorption and red cell transfusions causes an increase in liver iron and in various other tissues, leading to endocrine and cardiac dysfunction. Modern chelation regimens are effective in removing iron and preserving or restoring organ function.
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Affiliation(s)
- Arthur W Nienhuis
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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Cheadle C, Berger AE, Mathai SC, Grigoryev DN, Watkins TN, Sugawara Y, Barkataki S, Fan J, Boorgula M, Hummers L, Zaiman AL, Girgis R, McDevitt MA, Johns RA, Wigley F, Barnes KC, Hassoun PM. Erythroid-specific transcriptional changes in PBMCs from pulmonary hypertension patients. PLoS One 2012; 7:e34951. [PMID: 22545094 PMCID: PMC3335832 DOI: 10.1371/journal.pone.0034951] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 03/08/2012] [Indexed: 01/01/2023] Open
Abstract
Background Gene expression profiling of peripheral blood mononuclear cells (PBMCs) is a powerful tool for the identification of surrogate markers involved in disease processes. The hypothesis tested in this study was that chronic exposure of PBMCs to a hypertensive environment in remodeled pulmonary vessels would be reflected by specific transcriptional changes in these cells. Methodology/Principal Findings The transcript profiles of PBMCs from 30 idiopathic pulmonary arterial hypertension patients (IPAH), 19 patients with systemic sclerosis without pulmonary hypertension (SSc), 42 scleroderma-associated pulmonary arterial hypertensio patients (SSc-PAH), and 8 patients with SSc complicated by interstitial lung disease and pulmonary hypertension (SSc-PH-ILD) were compared to the gene expression profiles of PBMCs from 41 healthy individuals. Multiple gene expression signatures were identified which could distinguish various disease groups from controls. One of these signatures, specific for erythrocyte maturation, is enriched specifically in patients with PH. This association was validated in multiple published datasets. The erythropoiesis signature was strongly correlated with hemodynamic measures of increasing disease severity in IPAH patients. No significant correlation of the same type was noted for SSc-PAH patients, this despite a clear signature enrichment within this group overall. These findings suggest an association of the erythropoiesis signature in PBMCs from patients with PH with a variable presentation among different subtypes of disease. Conclusions/Significance In PH, the expansion of immature red blood cell precursors may constitute a response to the increasingly hypoxic conditions prevalent in this syndrome. A correlation of this erythrocyte signature with more severe hypertension cases may provide an important biomarker of disease progression.
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Affiliation(s)
- Chris Cheadle
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (CC); (PMH)
| | - Alan E. Berger
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Stephen C. Mathai
- Division of Pulmonary/Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Dmitry N. Grigoryev
- Medical Genetic Core, Children's Mercy Hospitals and Clinics, Kansas City, Missouri, United States of America
| | - Tonya N. Watkins
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Yumiko Sugawara
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sangjucta Barkataki
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jinshui Fan
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Meher Boorgula
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Laura Hummers
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ari L. Zaiman
- Division of Pulmonary/Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Reda Girgis
- Division of Pulmonary/Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Michael A. McDevitt
- Division of Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Roger A. Johns
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Frederick Wigley
- Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Kathleen C. Barnes
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Paul M. Hassoun
- Division of Pulmonary/Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail: (CC); (PMH)
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Mollan TL, Khandros E, Weiss MJ, Olson JS. Kinetics of α-globin binding to α-hemoglobin stabilizing protein (AHSP) indicate preferential stabilization of hemichrome folding intermediate. J Biol Chem 2012; 287:11338-50. [PMID: 22298770 DOI: 10.1074/jbc.m111.313247] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human α-hemoglobin stabilizing protein (AHSP) is a conserved mammalian erythroid protein that facilitates the production of Hemoglobin A by stabilizing free α-globin. AHSP rapidly binds to ferrous α with association (k'(AHSP)) and dissociation (k(AHSP)) rate constants of ≈10 μm(-1) s(-1) and 0.2 s(-1), respectively, at pH 7.4 at 22 °C. A small slow phase was observed when AHSP binds to excess ferrous αCO. This slow phase appears to be due to cis to trans prolyl isomerization of the Asp(29)-Pro(30) peptide bond in wild-type AHSP because it was absent when αCO was mixed with P30A and P30W AHSP, which are fixed in the trans conformation. This slow phase was also absent when met(Fe(3+))-α reacted with wild-type AHSP, suggesting that met-α is capable of rapidly binding to either Pro(30) conformer. Both wild-type and Pro(30)-substituted AHSPs drive the formation of a met-α hemichrome conformation following binding to either met- or oxy(Fe(2+))-α. The dissociation rate of the met-α·AHSP complex (k(AHSP) ≈ 0.002 s(-1)) is ∼100-fold slower than that for ferrous α·AHSP complexes, resulting in a much higher affinity of AHSP for met-α. Thus, in vivo, AHSP acts as a molecular chaperone by rapidly binding and stabilizing met-α hemichrome folding intermediates. The low rate of met-α dissociation also allows AHSP to have a quality control function by kinetically trapping ferric α and preventing its incorporation into less stable mixed valence Hemoglobin A tetramers. Reduction of AHSP-bound met-α allows more rapid release to β subunits to form stable fully, reduced hemoglobin dimers and tetramers.
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Affiliation(s)
- Todd L Mollan
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251, USA
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Khandros E, Mollan TL, Yu X, Wang X, Yao Y, D'Souza J, Gell DA, Olson JS, Weiss MJ. Insights into hemoglobin assembly through in vivo mutagenesis of α-hemoglobin stabilizing protein. J Biol Chem 2012; 287:11325-37. [PMID: 22287545 DOI: 10.1074/jbc.m111.313205] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
α-Hemoglobin stabilizing protein (AHSP) is believed to facilitate adult Hemoglobin A assembly and protect against toxic free α-globin subunits. Recombinant AHSP binds multiple forms of free α-globin to stabilize their structures and inhibit precipitation. However, AHSP also stimulates autooxidation of αO(2) subunit and its rapid conversion to a partially unfolded bishistidyl hemichrome structure. To investigate these biochemical properties, we altered the evolutionarily conserved AHSP proline 30 in recombinantly expressed proteins and introduced identical mutations into the endogenous murine Ahsp gene. In vitro, the P30W AHSP variant bound oxygenated α chains with 30-fold increased affinity. Both P30W and P30A mutant proteins also caused decreased rates of αO(2) autooxidation as compared with wild-type AHSP. Despite these abnormalities, mice harboring P30A or P30W Ahsp mutations exhibited no detectable defects in erythropoiesis at steady state or during induced stresses. Further biochemical studies revealed that the AHSP P30A and P30W substitutions had minimal effects on AHSP interactions with ferric α subunits. Together, our findings indicate that the ability of AHSP to stabilize nascent α chain folding intermediates prior to hemin reduction and incorporation into adult Hemoglobin A is physiologically more important than AHSP interactions with ferrous αO(2) subunits.
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Affiliation(s)
- Eugene Khandros
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Brennan SO, Chan T, Duncan J. Novel α2 gene deletion (c.349_359 del GAGTTCACCCC) identified in association with the -α3.7 deletion. Hemoglobin 2011; 36:93-7. [PMID: 22121826 DOI: 10.3109/03630269.2011.637592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We report a novel α2 gene mutation identified in compound heterozygosity with the common -α(3.7) deletion. The mutation (c.349_359 del GAGTTCACCCC), causes a frameshift after codon α115 with the predicted extension of the αchain from 141 to 166 residues. The new polypeptide would be expected to have a mass of 17,463 Da, but no such product was detected in hemolysates, confirming the mutation's thalassemic phenotype. Mechanistically, the deletion is probably caused by replication slippage during DNA synthesis as the sequence is bracketed by a CC repeat. The lack of protein expression is probably caused by loss of critical binding sites to the chaperone, α Hb stabilizing protein (AHSP).
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Wajcman H, Vasseur C, Pissard S, Baudin-Creuza V. α-Hemoglobin Stabilizing Protein: A Modulating Factor in Thalassemias? Hemoglobin 2011; 35:463-8. [DOI: 10.3109/03630269.2011.576354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Szolajska E, Chroboczek J. Faithful chaperones. Cell Mol Life Sci 2011; 68:3307-22. [PMID: 21655914 PMCID: PMC3181412 DOI: 10.1007/s00018-011-0740-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 05/19/2011] [Accepted: 05/23/2011] [Indexed: 12/01/2022]
Abstract
This review describes the properties of some rare eukaryotic chaperones that each assist in the folding of only one target protein. In particular, we describe (1) the tubulin cofactors, (2) p47, which assists in the folding of collagen, (3) α-hemoglobin stabilizing protein (AHSP), (4) the adenovirus L4-100 K protein, which is a chaperone of the major structural viral protein, hexon, and (5) HYPK, the huntingtin-interacting protein. These various-sized proteins (102–1,190 amino acids long) are all involved in the folding of oligomeric polypeptides but are otherwise functionally unique, as they each assist only one particular client. This raises a question regarding the biosynthetic cost of the high-level production of such chaperones. As the clients of faithful chaperones are all abundant proteins that are essential cellular or viral components, it is conceivable that this necessary metabolic expenditure withstood evolutionary pressure to minimize biosynthetic costs. Nevertheless, the complexity of the folding pathways in which these chaperones are involved results in error-prone processes. Several human disorders associated with these chaperones are discussed.
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Affiliation(s)
- Ewa Szolajska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02106 Warsaw, Poland
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Alpha-hemoglobin-stabilizing protein: an erythroid molecular chaperone. Biochem Res Int 2011; 2011:373859. [PMID: 21490703 PMCID: PMC3070166 DOI: 10.1155/2011/373859] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 12/19/2010] [Indexed: 12/14/2022] Open
Abstract
Alpha-hemoglobin-stabilizing protein (AHSP) is an erythroid-specific protein that acts as a molecular chaperone for the free α chains of hemoglobin. Evidence strongly suggests that AHSP participates in hemoglobin synthesis and may act to neutralize the cytotoxic effects of excess free alpha-globin subunits that accumulate both in normal and beta-thalassemic erythroid precursor cells. As such, AHSP seems to be essential for normal erythropoiesis, and impaired upregulation of AHSP may lead to premature erythroid cell death, resulting in ineffective erythropoiesis. Reduced AHSP mRNA expression has been associated with clinical variability in some cases of β-thalassemia. It has been shown that αHb variants may also impair AHSP-αHb interactions, leading to pathological conditions that resemble α-thalassemia syndromes. The aim of this paper is to summarize current information concerning the structure and function of AHSP, focusing on its role in normal erythropoiesis and its relevance in health and disease.
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Lui FE, Kluger R. Reviving artificial blood: meeting the challenge of dealing with NO scavenging by hemoglobin. Chembiochem 2011; 11:1816-24. [PMID: 20661989 DOI: 10.1002/cbic.201000291] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Francine E Lui
- Department of Chemistry, Davenport Laboratories, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada
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Mollan TL, Yu X, Weiss MJ, Olson JS. The role of alpha-hemoglobin stabilizing protein in redox chemistry, denaturation, and hemoglobin assembly. Antioxid Redox Signal 2010; 12:219-31. [PMID: 19659437 PMCID: PMC2821148 DOI: 10.1089/ars.2009.2780] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Hemoglobin biosynthesis in erythrocyte precursors involves several steps. The correct ratios and concentrations of normal alpha (alpha) and beta (beta) globin proteins must be expressed; apoproteins must be folded correctly; heme must be synthesized and incorporated into these globins rapidly; and the individual alpha and beta subunits must be rapidly and correctly assembled into heterotetramers. These events occur on a large scale in vivo, and dysregulation causes serious clinical disorders such as thalassemia syndromes. Recent work has implicated a conserved erythroid protein known as Alpha-Hemoglobin Stabilizing Protein (AHSP) as a participant in these events. Current evidence suggests that AHSP enhances alpha subunit stability and diminishes its participation in harmful redox chemistry. There is also evidence that AHSP facilitates one or more early-stage post-translational hemoglobin biosynthetic events. In this review, recent experimental results are discussed in light of several current models describing globin subunit folding, heme uptake, assembly, and denaturation during hemoglobin synthesis. Particular attention is devoted to molecular interactions with AHSP that relate to alpha chain oxidation and the ability of alpha chains to associate with partner beta chains.
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Affiliation(s)
- Todd L Mollan
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251-1892, USA
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