1
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Huang S, Reed C, Ilsley M, Magor G, Tallack M, Landsberg M, Mitchell H, Gillinder K, Perkins A. Mutations in linker-2 of KLF1 impair expression of membrane transporters and cytoskeletal proteins causing hemolysis. Nat Commun 2024; 15:7019. [PMID: 39147774 PMCID: PMC11327367 DOI: 10.1038/s41467-024-50579-4] [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: 03/13/2023] [Accepted: 07/09/2024] [Indexed: 08/17/2024] Open
Abstract
The SP/KLF family of transcription factors harbour three C-terminal C2H2 zinc fingers interspersed by two linkers which confers DNA-binding to a 9-10 bp motif. Mutations in KLF1, the founding member of the family, are common. Missense mutations in linker two result in a mild phenotype. However, when co-inherited with loss-of-function mutations, they result in severe non-spherocytic hemolytic anemia. We generate a mouse model of this disease by crossing Klf1+/- mice with Klf1H350R/+ mice that harbour a missense mutation in linker-2. Klf1H350R/- mice exhibit severe hemolysis without thalassemia. RNA-seq demonstrate loss of expression of genes encoding transmembrane and cytoskeletal proteins, but not globins. ChIP-seq show no change in DNA-binding specificity, but a global reduction in affinity, which is confirmed using recombinant proteins and in vitro binding assays. This study provides new insights into how linker mutations in zinc finger transcription factors result in different phenotypes to those caused by loss-of-function mutations.
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Affiliation(s)
- Stephen Huang
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia
- School of Biomedical Sciences, The University of Queensland, St Lucia, Australia
| | - Casie Reed
- Australian Centre for Blood Diseases, Monash University, Clayton, Australia
| | - Melissa Ilsley
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia
- School of Biomedical Sciences, The University of Queensland, St Lucia, Australia
| | - Graham Magor
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia
- Australian Centre for Blood Diseases, Monash University, Clayton, Australia
| | - Michael Tallack
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia
| | - Michael Landsberg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia
| | - Helen Mitchell
- Australian Centre for Blood Diseases, Monash University, Clayton, Australia
| | - Kevin Gillinder
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia
- Australian Centre for Blood Diseases, Monash University, Clayton, Australia
| | - Andrew Perkins
- Mater Research Institute - UQ, The University of Queensland, St Lucia, Australia.
- School of Biomedical Sciences, The University of Queensland, St Lucia, Australia.
- Australian Centre for Blood Diseases, Monash University, Clayton, Australia.
- Department of Haematology, The Alfred Hospital, Melbourne, Australia.
- Biodiscovery Institute, Monash University, Clayton, Australia.
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2
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Olivotto S, Freddi A, Previtali R, Mauri A, Cereda C, De Amicis R, Bertoli S, Doneda C, Veggiotti P. Stroke and Stroke-Like Episodes: Recurrent Manifestations in GLUT1 Deficiency Syndrome. Pediatr Neurol 2024; 157:118-126. [PMID: 38914025 DOI: 10.1016/j.pediatrneurol.2024.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 05/13/2024] [Accepted: 05/30/2024] [Indexed: 06/26/2024]
Abstract
BACKGROUND Since the initial description of glucose transporter-1 deficiency syndrome (Glut1-DS) the phenotype of the condition has expanded, even leading to the recognition of atypical manifestations. We report on eight patients with Glut1-DS who experienced at least one episode of acute focal neurological deficits. METHODS We conducted a retrospective analysis, collecting clinical, electrophysiological, neuroradiological, and genetic information. We focused in particular on three well-documented cases. RESULTS Among 42 patients with Glut1-DS, eight individuals aged between six and 38 years presented with an acute onset of neurological disturbances: dysarthria/aphasia, oral dyskinesia, swallowing difficulties, paresthesia, facial palsy, hemi/monoplegia, vomiting, headache, and behavioral disturbances. When performed, magnetic resonance imaging (MRI) revealed signs of venous congestion and hypoperfusion and electroencephalography showed focal contralateral slowing. Deficits were transient in all patients but one. Four patients (50%) were on a ketogenic diet (KD), and two of these patients had lower than usual ketonemia levels during the episode. In two patients, MRI demonstrated the presence of an ischemic brain lesion. CONCLUSIONS In Glut1-DS, stroke-like episodes are a recurrent manifestation, particularly during early adulthood, and they were reported in 19% of the patients in our cohort. Stroke mimics should be considered a key feature of Glut1-DS, as other paroxysmal disorders. It remains to be established whether a KD can prevent the recurrence of episodes and, if so, at what level of ketosis. Further observations are needed to confirm the correlation between Glut1-DS and ischemic stroke.
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Affiliation(s)
- Sara Olivotto
- Pediatric Neurology Unit, Buzzi Children's Hospital, Milan, Italy
| | | | - Roberto Previtali
- University of Milan, Milan, Italy; Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Alessia Mauri
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy; Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Cristina Cereda
- Center of Functional Genomics and Rare Diseases, Department of Pediatrics, Buzzi Children's Hospital, Milan, Italy
| | - Ramona De Amicis
- International Center for the Assessment of Nutritional Status and the Development of Dietary Intervention Strategies (ICANS-DIS), Department of Food Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy; IRCCS Istituto Auxologico Italiano, Obesity Unit and Laboratory of Nutrition and Obesity Research, Department of Endocrine and Metabolic Diseases, Milan, Italy
| | - Simona Bertoli
- International Center for the Assessment of Nutritional Status and the Development of Dietary Intervention Strategies (ICANS-DIS), Department of Food Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy; IRCCS Istituto Auxologico Italiano, Obesity Unit and Laboratory of Nutrition and Obesity Research, Department of Endocrine and Metabolic Diseases, Milan, Italy
| | - Chiara Doneda
- Pediatric Radiology and Neuroradiology Unit, Buzzi Children's Hospital, Milan, Italy
| | - Pierangelo Veggiotti
- Pediatric Neurology Unit, Buzzi Children's Hospital, Milan, Italy; Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.
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3
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Hayden AN, Brandel KL, Merlau PR, Vijayakumar P, Leptich EJ, Pietryk EW, Gaytan ES, Ni CW, Chao HT, Rosenfeld JA, Arey RN. Behavioral screening of conserved RNA-binding proteins reveals CEY-1/YBX RNA-binding protein dysfunction leads to impairments in memory and cognition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574402. [PMID: 38260399 PMCID: PMC10802296 DOI: 10.1101/2024.01.05.574402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
RNA-binding proteins (RBPs) regulate translation and plasticity which are required for memory. RBP dysfunction has been linked to a range of neurological disorders where cognitive impairments are a key symptom. However, of the 2,000 RBPs in the human genome, many are uncharacterized with regards to neurological phenotypes. To address this, we used the model organism C. elegans to assess the role of 20 conserved RBPs in memory. We identified eight previously uncharacterized memory regulators, three of which are in the C. elegans Y-Box (CEY) RBP family. Of these, we determined that cey-1 is the closest ortholog to the mammalian Y-Box (YBX) RBPs. We found that CEY-1 is both necessary in the nervous system for memory ability and sufficient to increase memory. Leveraging human datasets, we found both copy number variation losses and single nucleotide variants in YBX1 and YBX3 in individuals with neurological symptoms. We identified one predicted deleterious YBX3 variant of unknown significance, p.Asn127Tyr, in two individuals with neurological symptoms. Introducing this variant into endogenous cey-1 locus caused memory deficits in the worm. We further generated two humanized worm lines expressing human YBX3 or YBX1 at the cey-1 locus to test evolutionary conservation of YBXs in memory and the potential functional significance of the p.Asn127Tyr variant. Both YBX1/3 can functionally replace cey-1, and introduction of p.Asn127Tyr into the humanized YBX3 locus caused memory deficits. Our study highlights the worm as a model to reveal memory regulators and identifies YBX dysfunction as a potential new source of rare neurological disease.
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Affiliation(s)
- Ashley N Hayden
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Katie L Brandel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Paul R Merlau
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | | | - Emily J Leptich
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Edward W Pietryk
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
| | - Elizabeth S Gaytan
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Postbaccalaureate Research Education Program, Baylor College of Medicine, Houston, TX, 77030
| | - Connie W Ni
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Neuroscience, Rice University, Houston, TX 77005
| | - Hsiao-Tuan Chao
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, 77030
- Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, 77030
- McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX, 77030
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
- Baylor Genetics Laboratories, Houston, TX 77021
| | - Rachel N Arey
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030
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4
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Stevens-Hernandez CJ, Gyorffy G, Meli A, New HV, Cardigan R, Bruce LJ. Vesiculation in irradiated and cation-leaky-stored red blood cells. Transfusion 2024; 64:150-161. [PMID: 37952228 DOI: 10.1111/trf.17593] [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: 08/09/2023] [Accepted: 10/14/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND Extracellular vesicles (EVs) are released by red blood cells (RBCs) throughout their life-span and also during hypothermic storage when they accumulate in the blood bag. We queried whether stored RBCs with increased cation permeability, either from donors with familial pseudohyperkalaemia (FP) or caused by irradiation, vesiculate more readily. STUDY DESIGN AND METHODS Recent technical advances have revealed at least two sub-populations of MVs in RBC storage units: macrovesicles (2-6 μm) and microvesicles (1-2 μm). Using nanoparticle tracking analysis, imaging flow cytometry, and protein quantification methods, we measured and characterized vesicles released by RBCs from control and FP individuals at three different storage time-points (day 4, day 17, and day 29). The RBCs had either been stored untreated or irradiated on either day 1 or day 14 of storage. RESULTS We found no difference in the number or size of vesicles released between cation-leaky FP RBCs and non-FP controls. Similarly, irradiated and non-irradiated RBCs showed very similar patterns of vesicle release to during cold-storage. The only significant difference in vesicle release was the increase in accumulated vesicles with length of storage time which has been reported previously. DISCUSSION EVs in stored blood are potential contributors to adverse transfusion reactions. The number of vesicles released during 35-day hypothermic storage varies between donors and increases with storage duration. However, increased cation permeability and irradiation do not appear to affect vesicle formation during RBC cold-storage.
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Affiliation(s)
- Christian J Stevens-Hernandez
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
- School of Biochemistry, University of Bristol, Bristol, UK
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Gyongyver Gyorffy
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
- School of Biochemistry, University of Bristol, Bristol, UK
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Athinoula Meli
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Helen V New
- Transfusion Directorate, NHS Blood and Transplant, London, UK
| | - Rebecca Cardigan
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
- Department of Haematology, University of Cambridge, Cambridge, UK
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
- School of Biochemistry, University of Bristol, Bristol, UK
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
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5
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Allegrini B, NGuyen LD, Mignotet M, Etchebest C, Fenneteau O, Platon J, Lambilliotte A, Guizouarn H, Da Costa L. Next generation sequencing (NGS) interest in deciphering erythrocyte molecular defects' association in red cell disorders: Clinical and erythrocyte phenotypes of patients with mutations inheritance in PIEZO1, Spectrin ß1, RhAG and SLC4A1. Blood Cells Mol Dis 2023; 103:102780. [PMID: 37516005 DOI: 10.1016/j.bcmd.2023.102780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 07/31/2023]
Abstract
We report here an instructive case referred at 16 months-old for exploration of hemolysis without anemia (compensated anemia with reticulocytosis). The biology tests confirmed the hemolysis with increased total and indirect bilirubin. The usual hemolysis diagnosis tests were normal (DAT, G6PD, PK, Hb electrophoresis) except cytology and ektacytometry suggesting an association of multiple red blood cell (RBC) membrane disorders. This led us to propose a molecular screening analysis using targeted-Next Generation Sequencing (t-NGS) with a capture technique on 93 genes involved in RBC and erythropoiesis defects. We identified 4 missense heterozygous allelic variations, all of them were described without any significance (VUS) in the SLC4A1, RhAG, PIEZO1 and SPTB genes. The study of the familial cosegregation and research functional tests allowed to decipher the role of at least two by two genes in the phenotype and the hemolytic disease of this young patient. Specialized t-NGS panel (or virtual exome/genome sequencing) in a disease-referent laboratory and the motivated collaboration of clinicians, biologists and scientists should be the gold standard for improving the diagnosis of the patients affected with RBC diseases or rare inherited anemias.
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Affiliation(s)
- Benoit Allegrini
- Université Côte d'Azur, CNRS, Inserm, Institut Biologie Valrose, Nice, France
| | | | - Morgane Mignotet
- Université Côte d'Azur, CNRS, Inserm, Institut Biologie Valrose, Nice, France
| | - Catherine Etchebest
- Inserm U1134, France; Laboratory of Excellence for RBCs, LABEX GR-Ex, 75015 Paris, France
| | - Odile Fenneteau
- AP-HP, Service Hématologie Biologique, Hôpital R. Debré, Paris, France
| | - Jessica Platon
- HEMATIM EA4666, Université Picardie Jules Vernes, Amiens, France
| | | | - Hélène Guizouarn
- Université Côte d'Azur, CNRS, Inserm, Institut Biologie Valrose, Nice, France; Laboratory of Excellence for RBCs, LABEX GR-Ex, 75015 Paris, France.
| | - Lydie Da Costa
- AP-HP, Service Hématologie Biologique, Hôpital R. Debré, Paris, France; HEMATIM EA4666, Université Picardie Jules Vernes, Amiens, France; Université Paris, Paris, France; Inserm U1134, France
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6
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Stewart GW, Gibson JS, Rees DC. The cation-leaky hereditary stomatocytosis syndromes: A tale of six proteins. Br J Haematol 2023; 203:509-522. [PMID: 37679660 DOI: 10.1111/bjh.19093] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/13/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023]
Abstract
This review concerns a series of dominantly inherited haemolytic anaemias in which the membrane of the erythrocyte 'leaks' the univalent cations, compromising the osmotic stability of the cell. The majority of the conditions are explained by mutations in one of six genes, coding for multispanning membrane proteins of different structure and function. These are: RhAG, coding for an ammonium carrier; SLC4A1, coding for the band 3 anion exchanger; PIEZO1, coding for a mechanosensitive cation channel; GLUT1, coding for a glucose transporter; KCNN4, coding for an internal-calcium-activated potassium channel; and ABCB6, coding for a porphyrin transporter. This review describes the five clinical syndromes associated with genetic defects in these genes and their variable genotype/phenotype relationships.
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Affiliation(s)
- Gordon W Stewart
- Division of Medicine, Faculty of Medical Sciences, University College London, London, UK
| | - John S Gibson
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - David C Rees
- Haematological Medicine, Kings College London, London, UK
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7
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Ghaderi S, Levkau B. An erythrocyte-centric view on the MFSD2B sphingosine-1-phosphate transporter. Pharmacol Ther 2023; 249:108483. [PMID: 37390971 DOI: 10.1016/j.pharmthera.2023.108483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/12/2023] [Accepted: 06/26/2023] [Indexed: 07/02/2023]
Abstract
MFSD2B has been identified as the exclusive sphingosine-1-phosphate (S1P) transporter in red blood cells (RBC) and platelets. MFSD2B-mediated S1P export from platelets is required for aggregation and thrombus formation, whereas RBC MFSD2B maintains plasma S1P levels in concert with SPNS2, the vascular and lymphatic endothelial cell S1P exporter, to control endothelial permeability and ensure normal vascular development. However, the physiological function of MFSD2B in RBC remains rather elusive despite mounting evidence that the intracellular S1P pool plays important roles in RBC glycolysis, adaptation to hypoxia and the regulation of cell shape, hydration, and cytoskeletal organisation. The large accumulation of S1P and sphingosine in MFSD2B-deficient RBC coincides with stomatocytosis and membrane abnormalities, the reasons for which have remained obscure. MFS family members transport substrates in a cation-dependent manner along electrochemical gradients, and disturbances in cation permeability are known to alter cell hydration and shape in RBC. Furthermore, the mfsd2 gene is a transcriptional target of GATA together with mylk3, the gene encoding myosin light chain kinase (MYLK). S1P is known to activate MYLK and thereby impact on myosin phosphorylation and cytoskeletal architecture. This suggests that metabolic, transcriptional and functional interactions may exist between MFSD2B-mediated S1P transport and RBC deformability. Here, we review the evidence for such interactions and the implications for RBC homeostasis.
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Affiliation(s)
- Shahrooz Ghaderi
- Institute of Molecular Medicine III, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany
| | - Bodo Levkau
- Institute of Molecular Medicine III, University Hospital Düsseldorf, Heinrich Heine University Düsseldorf, Germany.
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8
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Wang RC, Lee EE, De Simone N, Kathote G, Primeaux S, Avila A, Yu DM, Johnson M, Good LB, Jakkamsetti V, Sarode R, Holland AA, Pascual JM. Red blood cells as glucose carriers to the human brain: Modulation of cerebral activity by erythrocyte exchange transfusion in Glut1 deficiency (G1D). J Cereb Blood Flow Metab 2023; 43:357-368. [PMID: 36523131 PMCID: PMC9941860 DOI: 10.1177/0271678x221146121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 12/23/2022]
Abstract
Red blood cells circulating through the brain are briefly but closely apposed to the capillary endothelium. We hypothesized that this contact provides a nearly direct pathway for metabolic substrate transfer to neural cells that complements the better characterized plasma to endothelium transfer. While brain function is considered independent of normal fluctuations in blood glucose concentration, this is not borne out by persons with glucose transporter I (GLUT1) deficiency (G1D). In them, encephalopathy is often ameliorated by meal or carbohydrate administration, and this enabled us to test our hypothesis: Since red blood cells contain glucose, and since the red cells of G1D individuals are also deficient in GLUT1, replacing them with normal donor cells via exchange transfusion could augment erythrocyte to neural cell glucose transport via mass action in the setting of unaltered erythrocyte count or plasma glucose abundance. This motivated us to perform red blood cell exchange in 3 G1D persons. There were rapid, favorable and unprecedented changes in cognitive, electroencephalographic and quality-of-life measures. The hypothesized transfer mechanism was further substantiated by in vitro measurement of direct erythrocyte to endothelial cell glucose flux. The results also indicate that the adult intellect is capable of significant enhancement without deliberate practice. ClinicalTrials.gov registration: NCT04137692 https://clinicaltrials.gov/ct2/show/NCT04137692.
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Affiliation(s)
- Richard C Wang
- Department of Dermatology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Eunice E Lee
- Department of Dermatology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Nicole De Simone
- Department of Pathology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Gauri Kathote
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Sharon Primeaux
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Adrian Avila
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Dong-Min Yu
- Department of Dermatology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Mark Johnson
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Levi B Good
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Vikram Jakkamsetti
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Ravi Sarode
- Departments of Pathology and Internal Medicine, The University
of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Alice Ann Holland
- Department of Psychiatry, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
| | - Juan M Pascual
- Rare Brain Disorders Program, The University of Texas
Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
- Department of Physiology, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
- Department of Pediatrics, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
- Eugene McDermott Center for Human Growth &
Development/Center for Human Genetics, The University of Texas Southwestern
Medical Center, Dallas, Texas, USA
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9
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Meli A, Linger R, Stevens-Hernandez CJ, Gyongyver G, Marks DC, Aung HH, Tan JCG, Cardigan R, Bruce LJ, New HV. The compound effect of irradiation and familial pseudohyperkalemia on potassium leak from red blood cells. Transfusion 2022; 62:2587-2595. [PMID: 36285891 DOI: 10.1111/trf.17159] [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: 07/26/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND Familial pseudohyperkalemia (FP) is a rare asymptomatic condition characterized by an increased rate of potassium leak from red blood cells (RBC) on refrigeration. Gamma irradiation compromises RBC membrane integrity and accelerates potassium leakage. Here, we compared the effect of irradiation, applied early or late in storage, on FP versus non-FP RBC. STUDY DESIGN Five FP and 10 non-FP individuals from the National Institute for Health Research Cambridge BioResource, UK, and three FP and six non-FP individuals identified by Australian Red Cross Lifeblood consented to the study. Blood was collected according to standard practice in each center, held overnight at 18-24°C, leucocyte-depleted, and processed into red cell concentrates (RCC) in Saline Adenine Glucose Mannitol. On Day 1, RCC were split equally into six Red Cell Splits (RCS). Two RCS remained non-irradiated, two were irradiated on Day 1 and two were irradiated on Day 14. RBCs were tested over cold storage for quality parameters. RESULTS As expected, non-irradiated FP RCS had significantly higher supernatant potassium levels than controls throughout 28 days of storage (p < .001). When irradiated early, FP RCS released potassium at similar rates to control. When irradiated late, FP RCS supernatants had higher initial post-irradiation potassium concentration than controls but were similar to controls by the end of storage (14 days post-irradiation). No other parameters studied showed a significant difference between FP and control. DISCUSSION FP does not increase the rate of potassium leak from irradiated RBCs. Irradiation may cause a membrane defect similar to that in FP RBCs.
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Affiliation(s)
- Athinoula Meli
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK
| | - Rachel Linger
- National Institute for Health Research BioResource-Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Christian J Stevens-Hernandez
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Gyorffy Gyongyver
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
| | - Denese C Marks
- Research and Development, Australian Red Cross Lifeblood, Alexandria, Australia
| | - Htet Htet Aung
- Research and Development, Australian Red Cross Lifeblood, Alexandria, Australia
| | - Joanne C G Tan
- Research and Development, Australian Red Cross Lifeblood, Alexandria, Australia
| | - Rebecca Cardigan
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Department of Haematology, University of Cambridge, Cambridge, UK
| | - Lesley J Bruce
- Component Development Laboratory, NHS Blood and Transplant, Cambridge, UK.,Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, UK
| | - Helen V New
- Clinical Directorate, NHS Blood and Transplant, London, UK
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10
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Liu X, Liang L, Wu B, Zhang X, Zeng X, Deng Y, Peng B, Zhang X, Zheng L. Effect of the R126C mutation on the structure and function of the glucose transporter GLUT1: A molecular dynamics simulation study. J Mol Graph Model 2022; 116:108227. [PMID: 35671570 DOI: 10.1016/j.jmgm.2022.108227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 12/14/2022]
Abstract
Glucose transporter 1 (GLUT1) is responsible for basal glucose uptake and is expressed in most tissues under normal conditions. GLUT1 mutations can cause early-onset absence epilepsy and myoclonus dystonia syndrome (MDS), with MDS potentially lethal. In this study, the effect of the R126C mutation, which is associated with MDS, on structural stability and substrate transport of GLUT1 was investigated. Various bioinformatics tools were used to predict the stability of GLUT1, revealing that the R126C mutation reduces the structural stability of GLUT1. Molecular dynamics (MD) simulations were used to further characterize the effect of the R126C mutation on GLUT1 structural stability. Based on the MD simulations, specific conformational changes and dominant motions of the GLUT1 mutant were characterized by Principal component analysis (PCA). The mutation disrupts hydrogen bonds between substrate-binding residues and glucose, thus likely reducing substrate affinity. The R126C mutation reduces the conformational stability of the protein, and fewer intramolecular hydrogen bonds were present in the mutated GLUT1 when compared with that of wild-type GLUT1. The mutation increased the free energy of glucose transport through GLUT1 significantly, especially at the mutation site, indicating that passage of glucose through the channel is hindered, and this mutant may even release cytoplasmic glucose. This study provides a detailed atomic-level explanation for the reduced structural stability and substrate transport capacity of a GLUT1 mutant. The results aid our understanding of the structure of GLUT1 and provide a framework for developing drugs to treat GLUT1-related diseases, such as MDS.
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Affiliation(s)
- Xiaoliu Liu
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China; Medical Laboratory of Shenzhen Luohu People's Hospital, 518001, China
| | - Luguang Liang
- School of Laboratory Medicine, Guangdong Medical University, Dongguan, China
| | - Bodeng Wu
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Xin Zhang
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | | | - Yurong Deng
- Medical Laboratory of Shenzhen Luohu People's Hospital, 518001, China
| | - Bin Peng
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Xiuming Zhang
- Medical Laboratory of Shenzhen Luohu People's Hospital, 518001, China.
| | - Lei Zheng
- Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
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11
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Stevens-Hernandez CJ, Flatt JF, Kupzig S, Bruce LJ. Reticulocyte Maturation and Variant Red Blood Cells. Front Physiol 2022; 13:834463. [PMID: 35356079 PMCID: PMC8959883 DOI: 10.3389/fphys.2022.834463] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/15/2022] [Indexed: 01/08/2023] Open
Abstract
The bone marrow produces billions of reticulocytes daily. These reticulocytes mature into red blood cells by reducing their plasma membrane by 20% and ejecting or degrading residual internal organelles, membranes and proteins not required by the mature cell. This process occurs by autophagy, protein degradation and vesiculation but is not well understood. We previously reported that Southeast Asian Ovalocytic RBCs demonstrate incomplete reticulocyte maturation and we have now extended this study to a number of other variant RBCs. By comparing the profile of a pure reticulocyte preparation of cultured red cells with these variant cells, we show that the largest of these cells, the overhydrated hereditary stomatocytosis cells, are the least mature, they barely reduced their plasma membrane and contain large amounts of proteins that should have been reduced or removed. Intermediate sized variant RBCs appear to be more mature but retain some endoplasmic reticulum and residual membrane proteins. We propose that the size and composition of these variant cell types correlate with the different stages of reticulocyte maturation and provide insight into the reticulocyte maturation process.
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Affiliation(s)
- Christian J Stevens-Hernandez
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom.,School of Biochemistry, University of Bristol, Bristol, United Kingdom.,Component Development Laboratory, NHS Blood and Transplant, Long Road, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Joanna F Flatt
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom.,School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Sabine Kupzig
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom.,School of Biochemistry, University of Bristol, Bristol, United Kingdom.,Component Development Laboratory, NHS Blood and Transplant, Long Road, Cambridge Biomedical Campus, Cambridge, United Kingdom
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12
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Stevens-Hernandez CJ, Bruce LJ. Reticulocyte Maturation. MEMBRANES 2022; 12:311. [PMID: 35323786 PMCID: PMC8953437 DOI: 10.3390/membranes12030311] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 02/04/2023]
Abstract
Changes to the membrane proteins and rearrangement of the cytoskeleton must occur for a reticulocyte to mature into a red blood cell (RBC). Different mechanisms of reticulocyte maturation have been proposed to reduce the size and volume of the reticulocyte plasma membrane and to eliminate residual organelles. Lysosomal protein degradation, exosome release, autophagy and the extrusion of large autophagic-endocytic hybrid vesicles have been shown to contribute to reticulocyte maturation. These processes may occur simultaneously or perhaps sequentially. Reticulocyte maturation is incompletely understood and requires further investigation. RBCs with membrane defects or cation leak disorders caused by genetic variants offer an insight into reticulocyte maturation as they present characteristics of incomplete maturation. In this review, we compare the structure of the mature RBC membrane with that of the reticulocyte. We discuss the mechanisms of reticulocyte maturation with a focus on incomplete reticulocyte maturation in red cell variants.
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Affiliation(s)
- Christian J Stevens-Hernandez
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol BS34 7QH, UK
- School of Biochemistry, University of Bristol, Bristol BS8 ITD, UK
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol BS34 7QH, UK
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13
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von Lindern M, Egée S, Bianchi P, Kaestner L. The Function of Ion Channels and Membrane Potential in Red Blood Cells: Toward a Systematic Analysis of the Erythroid Channelome. Front Physiol 2022; 13:824478. [PMID: 35177994 PMCID: PMC8844196 DOI: 10.3389/fphys.2022.824478] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/04/2022] [Indexed: 01/14/2023] Open
Abstract
Erythrocytes represent at least 60% of all cells in the human body. During circulation, they experience a huge variety of physical and chemical stimulations, such as pressure, shear stress, hormones or osmolarity changes. These signals are translated into cellular responses through ion channels that modulate erythrocyte function. Ion channels in erythrocytes are only recently recognized as utmost important players in physiology and pathophysiology. Despite this awareness, their signaling, interactions and concerted regulation, such as the generation and effects of “pseudo action potentials”, remain elusive. We propose a systematic, conjoined approach using molecular biology, in vitro erythropoiesis, state-of-the-art electrophysiological techniques, and channelopathy patient samples to decipher the role of ion channel functions in health and disease. We need to overcome challenges such as the heterogeneity of the cell population (120 days lifespan without protein renewal) or the access to large cohorts of patients. Thereto we will use genetic manipulation of progenitors, cell differentiation into erythrocytes, and statistically efficient electrophysiological recordings of ion channel activity.
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Affiliation(s)
- Marieke von Lindern
- Sanquin Research and Landsteiner Laboratory, Department of Hematopoiesis, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Stéphane Egée
- Integrative Biology of Marine Models, Station Biologique de Roscoff, CNRS, UMR 8227, Sorbonne Université, Roscoff Cedex, France
- Laboratoire d’Excellence GR-Ex, Paris, France
| | - Paola Bianchi
- Pathophysiology of Anemia Unit, Hematology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan, Milan, Italy
| | - Lars Kaestner
- Theoretical Medicine and Biosciences, Medical Faculty, Saarland University, Homburg, Germany
- Dynamics of Fluids, Experimental Physics, Saarland University, Saarbrücken, Germany
- *Correspondence: Lars Kaestner,
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14
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Hu Q, Shen Y, Su T, Liu Y, Xu S. Clinical and Genetic Characteristics of Chinese Children With GLUT1 Deficiency Syndrome: Case Report and Literature Review. Front Genet 2021; 12:734481. [PMID: 34880899 PMCID: PMC8645975 DOI: 10.3389/fgene.2021.734481] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/18/2021] [Indexed: 11/24/2022] Open
Abstract
Objective: GLUT1 deficiency syndrome (GLUT1-DS) is a rare, treatable neurometabolic disorder. However, its diagnosis may be challenging due to the various and evolving phenotypes. Here we report the first Chinese familial cases with genetically confirmed GLUT1-DS and analyze the characteristics of Chinese children with GLUT1-DS from clinical, laboratory, and genetic aspects. Methods: We reported a Chinese family with three members affected with GLUT1-DS and searched for relevant articles up to September 2020 from PubMed, WOS, CNKI, and WanFang databases. A total of 30 Chinese patients diagnosed with GLUT1-DS (three newly identified patients in one family and 27 previously reported ones) were included and analyzed in this study. Results: The median age of onset of the 30 patients (male: 18, female: 12) was 8.5 months (range, 33 days to 10 years). Epileptic seizures were found in 25 patients, most with generalized tonic–clonic and focal ones. Movement disorders were found in 20 patients—frequently with ataxia and dystonia, developmental delay in 25 patients, and microcephaly only in six patients. The cerebrospinal fluid (CSF) analysis showed decreased CSF glucose (median: 1.63 mmol/L, range: 1.1–2.6 mmol/L) and glucose ratio of CSF to blood (median: 0.340; range: 0.215–0.484). The genetic testing performed in 28 patients revealed 27 cases with pathogenic variations of the SLC2A1 gene, including 10 missense, nine frameshift, three nonsense, three large fragment deletions, and two splice-site mutations. Most patients had a good response to the treatment of ketogenic diet or regular diet with increased frequency. Although three patients in this Chinese family carried the same pathogenic mutation c.73C > T (p.Q25X) in the SLC2A1 gene, their symptoms and responses to treatment were not exactly the same. Conclusion: The clinical manifestations of GLUT1-DS are heterogeneous, even among family members sharing the same mutation. For children with unexplained epileptic seizures, developmental delay, and complex movement disorders, detection of low CSF glucose or SLC2A1 gene mutations is helpful for the diagnosis of GLUT1-DS. Early initiation of ketogenic diet treatment significantly improves the symptoms and prognosis of GLUT1-DS.
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Affiliation(s)
- Qingqing Hu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Pediatrics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yuechi Shen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tangfeng Su
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Liu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sanqing Xu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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15
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Mir A, Almudhry M, Alghamdi F, Albaradie R, Ibrahim M, Aldurayhim F, Alhedaithy A, Alamr M, Bawazir M, Mohammad S, Abdelhay S, Bashir S, Housawi Y. SLC gene mutations and pediatric neurological disorders: diverse clinical phenotypes in a Saudi Arabian population. Hum Genet 2021; 141:81-99. [PMID: 34797406 DOI: 10.1007/s00439-021-02404-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022]
Abstract
The uptake and efflux of solutes across a plasma membrane is controlled by transporters. There are two main superfamilies of transporters, adenosine 5'-triphosphate (ATP) binding cassettes (ABCs) and solute carriers (SLCs). In the brain, SLC transporters are involved in transporting various solutes across the blood-brain barrier, blood-cerebrospinal fluid barrier, astrocytes, neurons, and other brain cell types including oligodendrocytes and microglial cells. SLCs play an important role in maintaining normal brain function. Hence, mutations in the genes that encode SLC transporters can cause a variety of neurological disorders. We identified the following SLC gene variants in 25 patients in our cohort: SLC1A2, SLC2A1, SLC5A1, SLC6A3, SLC6A5, SLC6A8, SLC9A6, SLC9A9, SLC12A6, SLC13A5, SLC16A1, SLC17A5, SLC19A3, SLC25A12, SLC25A15, SLC27A4, SLC45A1, SLC46A1, and SLC52A3. Eight patients harbored pathogenic or likely pathogenic mutations (SLC5A1, SLC9A6, SLC12A6, SLC16A1, SLC19A3, and SLC52A3), and 12 patients were found to have variants of unknown clinical significance (VOUS); these variants occurred in 11 genes (SLC1A2, SLC2A1, SLC6A3, SLC6A5, SLC6A8, SLC9A6, SLC9A9, SLC13A5, SLC25A12, SLC27A4, and SLC45A1). Five patients were excluded as they were carriers. In the remaining 20 patients with SLC gene variants, we identified 16 possible distinct neurological disorders. Based on the clinical presentation, we categorized them into genes causing intellectual delay (ID) or autism spectrum disorder (ASD), those causing epilepsy, those causing vitamin-related disorders, and those causing other neurological diseases. Several variants were detected that indicated possible personalized therapies: SLC2A1 led to dystonia or epilepsy, which can be treated with a ketogenic diet; SLC6A3 led to infantile parkinsonism-dystonia 1, which can be treated with levodopa; SLC6A5 led to hyperekplexia 3, for which unnecessary treatment with antiepileptic drugs should be avoided; SLC6A8 led to creatine deficiency syndrome type 1, which can be treated with creatine monohydrate; SLC16A1 led to monocarboxylate transporter 1 deficiency, which causes seizures that should not be treated with a ketogenic diet; SLC19A3 led to biotin-thiamine-responsive basal ganglia disease, which can be treated with biotin and thiamine; and SLC52A3 led to Brown-Vialetto-Van-Laere syndrome 1, which can be treated with riboflavin. The present study examines the prevalence of SLC gene mutations in our cohort of children with epilepsy and other neurological disorders. It highlights the diverse phenotypes associated with mutations in this large family of SLC transporter proteins, and an opportunity for personalized genomics and personalized therapeutics.
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Affiliation(s)
- Ali Mir
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia.
| | - Montaha Almudhry
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Fouad Alghamdi
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Raidah Albaradie
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Mona Ibrahim
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Fatimah Aldurayhim
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Abdullah Alhedaithy
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Mushari Alamr
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Maryam Bawazir
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Sahar Mohammad
- Department of Pediatric, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Salma Abdelhay
- Department of Pediatric, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Shahid Bashir
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Yousef Housawi
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
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16
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Patanè F, Pasquetti E, Sullo F, Tosto M, Romano C, Salafia S, Falsaperla R. SLC2A1 and Its Related Epileptic Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AbstractGlucose transporter type 1 deficiency syndrome (GLUT1DS) is caused by heterozygous, mostly de novo, mutations in SLC2A1 gene encoding the glucose transporter GLUT1, the most relevant energy transporter in the blood–brain barrier. GLUT1DS includes a broad spectrum of neurologic disturbances, from severe encephalopathy with developmental delay, to epilepsy, movement disorders, acquired microcephaly and atypical mild forms. For diagnosis, lumbar puncture and genetic analysis are necessary and complementary; an immediate response to ketogenic diet supports the diagnosis in case of high suspicion of disease and negative exams. The ketogenic diet is the first-line treatment and should be established at the initial stages of disease.
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Affiliation(s)
- Francesca Patanè
- Pediatric Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Elisa Pasquetti
- Pediatric Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Federica Sullo
- Pediatric Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Monica Tosto
- Pediatric Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | | | | | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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17
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Pizzagalli MD, Bensimon A, Superti‐Furga G. A guide to plasma membrane solute carrier proteins. FEBS J 2021; 288:2784-2835. [PMID: 32810346 PMCID: PMC8246967 DOI: 10.1111/febs.15531] [Citation(s) in RCA: 180] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022]
Abstract
This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.
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Affiliation(s)
- Mattia D. Pizzagalli
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ariel Bensimon
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaAustria
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18
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Red cell membrane disorders: structure meets function. Blood 2021; 136:1250-1261. [PMID: 32702754 DOI: 10.1182/blood.2019000946] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/06/2020] [Indexed: 12/12/2022] Open
Abstract
The mature red blood cell (RBC) lacks a nucleus and organelles characteristic of most cells, but it is elegantly structured to perform the essential function of delivering oxygen and removing carbon dioxide from all other cells while enduring the shear stress imposed by navigating small vessels and sinusoids. Over the past several decades, the efforts of biochemists, cell and molecular biologists, and hematologists have provided an appreciation of the complexity of RBC membrane structure, while studies of the RBC membrane disorders have offered valuable insights into structure-function relationships. Within the last decade, advances in genetic testing and its increased availability have made it possible to substantially build upon this foundational knowledge. Although disorders of the RBC membrane due to altered structural organization or altered transport function are heterogeneous, they often present with common clinical findings of hemolytic anemia. However, they may require substantially different management depending on the underlying pathophysiology. Accurate diagnosis is essential to avoid emergence of complications or inappropriate interventions. We propose an algorithm for laboratory evaluation of patients presenting with symptoms and signs of hemolytic anemia with a focus on RBC membrane disorders. Here, we review the genotypic and phenotypic variability of the RBC membrane disorders in order to raise the index of suspicion and highlight the need for correct and timely diagnosis.
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19
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Guizouarn H, Allegrini B. Erythroid glucose transport in health and disease. Pflugers Arch 2020; 472:1371-1383. [PMID: 32474749 DOI: 10.1007/s00424-020-02406-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/15/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022]
Abstract
Glucose transport is intimately linked to red blood cell physiology. Glucose is the unique energy source for these cells, and defects in glucose metabolism or transport activity are associated with impaired red blood cell morphology and deformability leading to reduced lifespan. In vertebrate erythrocytes, glucose transport is mediated by GLUT1 (in humans) or GLUT4 transporters. These proteins also account for dehydroascorbic acid (DHA) transport through erythrocyte membrane. The peculiarities of glucose transporters and the red blood cell pathologies involving GLUT1 are summarized in the present review.
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Affiliation(s)
- Hélène Guizouarn
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, 28 av. Valrose, 06100, Nice, France.
| | - Benoit Allegrini
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, 28 av. Valrose, 06100, Nice, France
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20
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Flatt JF, Stevens-Hernandez CJ, Cogan NM, Eggleston DJ, Haines NM, Heesom KJ, Picard V, Thomas C, Bruce LJ. Expression of South East Asian Ovalocytic Band 3 Disrupts Erythroblast Cytokinesis and Reticulocyte Maturation. Front Physiol 2020; 11:357. [PMID: 32411010 PMCID: PMC7199003 DOI: 10.3389/fphys.2020.00357] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/27/2020] [Indexed: 12/17/2022] Open
Abstract
Southeast Asian Ovalocytosis results from a heterozygous deletion of 9 amino acids in the erythrocyte anion exchange protein AE1 (band 3). The report of the first successful birth of an individual homozygous for this mutation showed an association with severe dyserythropoietic anemia. Imaging of the proband’s erythrocytes revealed the presence of band 3 at their surface, a reduction in Wr(b) antigen expression, and increases in glycophorin C, CD44, and CD147 immunoreactivity. Immunoblotting of membranes from heterozygous Southeast Asian Ovalocytosis red cells showed a quantitative increase in CD44, CD147, and calreticulin suggesting a defect in reticulocyte maturation, as well as an increase in phosphorylation at residue Tyr359 of band 3, and peroxiredoxin-2 at the membrane, suggesting altered band 3 trafficking and oxidative stress, respectively. In vitro culture of homozygous and heterozygous Southeast Asian Ovalocytosis erythroid progenitor cells produced bi- and multi-nucleated cells. Enucleation was severely impaired in the homozygous cells and reduced in the heterozygous cells. Large internal vesicular accumulations of band 3 formed, which co-localized with other plasma membrane proteins and with the autophagosome marker, LC3, but not with ER, Golgi or recycling endosome markers. Immunoprecipitation of band 3 from erythroblast cell lysates at the orthochromatic stage showed increased interaction of the mutant band 3 with heat shock proteins, ubiquitin and cytoskeleton proteins, ankyrin, spectrin and actin. We also found that the mutant band 3 forms a strong interaction with non-muscle myosins IIA and IIB, while this interaction could not be detected in wild type erythroblasts. Consistent with this, the localization of non-muscle myosin IIA and actin was perturbed in some Southeast Asian Ovalocytosis erythroblasts. These findings provide new insights toward understanding in vivo dyserythropoiesis caused by the expression of mutant membrane proteins.
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Affiliation(s)
- Joanna F Flatt
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom
| | - Christian J Stevens-Hernandez
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom.,School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Nicola M Cogan
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom
| | - Daniel J Eggleston
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom
| | - Nicole M Haines
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom
| | - Kate J Heesom
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Veronique Picard
- Assistance Publique-Hôpitaux de Paris, Service d'Hématologie Biologique, Hôpital Bicêtre, Paris, France.,Faculté de Pharmacie, Université Paris-Saclay, Chatenay Malabry, France
| | - Caroline Thomas
- Hématologie et Immunologie Pédiatrique, Hôpital Mère Enfants, Nantes, France
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, National Health Service (NHS) Blood and Transplant, Bristol, United Kingdom
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21
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Iolascon A, Andolfo I, Russo R. Advances in understanding the pathogenesis of red cell membrane disorders. Br J Haematol 2019; 187:13-24. [PMID: 31364155 DOI: 10.1111/bjh.16126] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hereditary erythrocyte membrane disorders are caused by mutations in genes encoding various transmembrane or cytoskeletal proteins of red blood cells. The main consequences of these genetic alterations are decreased cell deformability and shortened erythrocyte survival. Red blood cell membrane defects encompass a heterogeneous group of haemolytic anaemias caused by either (i) altered membrane structural organisation (hereditary spherocytosis, hereditary elliptocytosis, hereditary pyropoikilocytosis and Southeast Asian ovalocytosis) or (ii) altered membrane transport function (overhydrated hereditary stomatocytosis, dehydrated hereditary stomatocytosis or xerocytosis, familial pseudohyperkalaemia and cryohydrocytosis). Herein we provide a comprehensive review of the recent literature on the molecular genetics of erythrocyte membrane defects and their reported clinical consequences. We also describe the effect of low-expression genetic variants on the high inter- and intra-familial phenotype variability of erythrocyte structural defects.
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Affiliation(s)
- Achille Iolascon
- Department of Molecular Medicine and Medical Biotechnologies, Federico II" University of Naples, Naples, Italy.,CEINGE - Biotecnologie Avanzate, Naples, Italy
| | - Immacolata Andolfo
- Department of Molecular Medicine and Medical Biotechnologies, Federico II" University of Naples, Naples, Italy.,CEINGE - Biotecnologie Avanzate, Naples, Italy
| | - Roberta Russo
- Department of Molecular Medicine and Medical Biotechnologies, Federico II" University of Naples, Naples, Italy.,CEINGE - Biotecnologie Avanzate, Naples, Italy
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Risinger M, Emberesh M, Kalfa TA. Rare Hereditary Hemolytic Anemias: Diagnostic Approach and Considerations in Management. Hematol Oncol Clin North Am 2019; 33:373-392. [PMID: 31030808 DOI: 10.1016/j.hoc.2019.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hereditary hemolytic anemias (HHAs) comprise a heterogeneous group of anemias caused by mutations in genes coding the globins, red blood cell (RBC) membrane proteins, and RBC enzymes. Congenital dyserythropoietic anemias (CDAs) are rare disorders of erythropoiesis characterized by binucleated and multinucleated erythroblasts in bone marrow. CDAs typically present with a hemolytic phenotype, as the produced RBCs have structural defects and decreased survival and should be considered in the differential of HHAs. This article discusses the clinical presentation, laboratory findings, and management considerations for rare HHAs arising from unstable hemoglobins, RBC hydration defects, the less common RBC enzymopathies, and CDAs.
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Affiliation(s)
- Mary Risinger
- College of Nursing, University of Cincinnati, 3110 Vine Street, Cincinnati, OH 45221-0038, USA
| | - Myesa Emberesh
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7018, Cincinnati, OH 45229-3039, USA
| | - Theodosia A Kalfa
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7015, Cincinnati, OH 45229-3039, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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23
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Léveillard T, Philp NJ, Sennlaub F. Is Retinal Metabolic Dysfunction at the Center of the Pathogenesis of Age-related Macular Degeneration? Int J Mol Sci 2019; 20:ijms20030762. [PMID: 30754662 PMCID: PMC6387069 DOI: 10.3390/ijms20030762] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 01/12/2023] Open
Abstract
The retinal pigment epithelium (RPE) forms the outer blood⁻retina barrier and facilitates the transepithelial transport of glucose into the outer retina via GLUT1. Glucose is metabolized in photoreceptors via the tricarboxylic acid cycle (TCA) and oxidative phosphorylation (OXPHOS) but also by aerobic glycolysis to generate glycerol for the synthesis of phospholipids for the renewal of their outer segments. Aerobic glycolysis in the photoreceptors also leads to a high rate of production of lactate which is transported out of the subretinal space to the choroidal circulation by the RPE. Lactate taken up by the RPE is converted to pyruvate and metabolized via OXPHOS. Excess lactate in the RPE is transported across the basolateral membrane to the choroid. The uptake of glucose by cone photoreceptor cells is enhanced by rod-derived cone viability factor (RdCVF) secreted by rods and by insulin signaling. Together, the three cells act as symbiotes: the RPE supplies the glucose from the choroidal circulation to the photoreceptors, the rods help the cones, and both produce lactate to feed the RPE. In age-related macular degeneration this delicate ménage à trois is disturbed by the chronic infiltration of inflammatory macrophages. These immune cells also rely on aerobic glycolysis and compete for glucose and produce lactate. We here review the glucose metabolism in the homeostasis of the outer retina and in macrophages and hypothesize what happens when the metabolism of photoreceptors and the RPE is disturbed by chronic inflammation.
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Affiliation(s)
- Thierry Léveillard
- . Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Nancy J Philp
- . Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Florian Sennlaub
- . Department of Therapeutics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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Abstract
Inborn errors of metabolism, also known as inherited metabolic diseases, constitute an important group of conditions presenting with neurologic signs in newborns. They are individually rare but collectively common. Many are treatable through restoration of homeostasis of a disrupted metabolic pathway. Given their frequency and potential for treatment, the clinician should be aware of this group of conditions and learn to identify the typical manifestations of the different inborn errors of metabolism. In this review, we summarize the clinical, laboratory, electrophysiologic, and neuroimaging findings of the different inborn errors of metabolism that can present with florid neurologic signs and symptoms in the neonatal period.
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MESH Headings
- Adult
- Female
- Humans
- Infant, Newborn
- Infant, Newborn, Diseases/diagnosis
- Infant, Newborn, Diseases/diagnostic imaging
- Infant, Newborn, Diseases/physiopathology
- Infant, Newborn, Diseases/therapy
- Metabolism, Inborn Errors/diagnosis
- Metabolism, Inborn Errors/diagnostic imaging
- Metabolism, Inborn Errors/physiopathology
- Metabolism, Inborn Errors/therapy
- Neuroimaging
- Pregnancy
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Affiliation(s)
- Carlos R Ferreira
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States; Rare Disease Institute, Children's National Health System, Washington, DC, United States
| | - Clara D M van Karnebeek
- Departments of Pediatrics and Clinical Genetics, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Pediatrics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada.
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25
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Caulier A, Rapetti-Mauss R, Guizouarn H, Picard V, Garçon L, Badens C. Primary red cell hydration disorders: Pathogenesis and diagnosis. Int J Lab Hematol 2018; 40 Suppl 1:68-73. [DOI: 10.1111/ijlh.12820] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/09/2018] [Indexed: 11/26/2022]
Affiliation(s)
- A. Caulier
- EA HEMATIM; Université Picardie Jules Verne; Amiens France
| | | | - H. Guizouarn
- CNRS, INSERM, IBV; Université Côte d'Azur; Nice France
| | - V. Picard
- Faculté de Pharmacie; Université Paris Sud-Paris Saclay; Chatenay Malabry France
- AP-HP; Département d'Hématologie; Hôpital Bicêtre; Le Kremlin-Bicêtre France
| | - L. Garçon
- EA HEMATIM; Université Picardie Jules Verne; Amiens France
- Service d'Hématologie Biologique; CHU Amiens; Amiens France
| | - C. Badens
- INSERM, MMG; Aix Marseille University; Marseille France
- Laboratoire de Génétique Moléculaire; APHM; Marseille France
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26
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Flatt JF, Bruce LJ. The Molecular Basis for Altered Cation Permeability in Hereditary Stomatocytic Human Red Blood Cells. Front Physiol 2018; 9:367. [PMID: 29713289 PMCID: PMC5911802 DOI: 10.3389/fphys.2018.00367] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/27/2018] [Indexed: 11/20/2022] Open
Abstract
Normal human RBCs have a very low basal permeability (leak) to cations, which is continuously corrected by the Na,K-ATPase. The leak is temperature-dependent, and this temperature dependence has been evaluated in the presence of inhibitors to exclude the activity of the Na,K-ATPase and NaK2Cl transporter. The severity of the RBC cation leak is altered in various conditions, most notably the hereditary stomatocytosis group of conditions. Pedigrees within this group have been classified into distinct phenotypes according to various factors, including the severity and temperature-dependence of the cation leak. As recent breakthroughs have provided more information regarding the molecular basis of hereditary stomatocytosis, it has become clear that these phenotypes elegantly segregate with distinct genetic backgrounds. The cryohydrocytosis phenotype, including South-east Asian Ovalocytosis, results from mutations in SLC4A1, and the very rare condition, stomatin-deficient cryohydrocytosis, is caused by mutations in SLC2A1. Mutations in RHAG cause the very leaky condition over-hydrated stomatocytosis, and mutations in ABCB6 result in familial pseudohyperkalemia. All of the above are large multi-spanning membrane proteins and the mutations may either modify the structure of these proteins, resulting in formation of a cation pore, or otherwise disrupt the membrane to allow unregulated cation movement across the membrane. More recently mutations have been found in two RBC cation channels, PIEZO1 and KCNN4, which result in dehydrated stomatocytosis. These mutations alter the activation and deactivation kinetics of these channels, leading to increased opening and allowing greater cation fluxes than in wild type.
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Affiliation(s)
- Joanna F Flatt
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom
| | - Lesley J Bruce
- Bristol Institute for Transfusion Sciences, NHS Blood and Transplant, Bristol, United Kingdom
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Andolfo I, Russo R, Gambale A, Iolascon A. Hereditary stomatocytosis: An underdiagnosed condition. Am J Hematol 2018; 93:107-121. [PMID: 28971506 DOI: 10.1002/ajh.24929] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/26/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022]
Abstract
Hereditary stomatocytoses are a wide class of hemolytic anemias characterized by alterations of ionic flux with increased cation permeability that results in inappropriate shrinkage or swelling of the erythrocytes, and water lost or gained osmotically. The last few years have been crucial for new acquisitions in this field in terms of identifying new causative genes and of studying their pathogenetic mechanisms. This review summarizes the main features of erythrocyte membrane transport diseases, dividing them into forms with either isolated erythroid phenotype (nonsyndromic) or extra-hematological manifestations (syndromic), and focusing particularly on the most recent advances regarding dehydrated forms of hereditary stomatocytosis and familial pseudohyperkalemia.
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Affiliation(s)
- Immacolata Andolfo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II; Napoli Italy
- CEINGE Biotecnologie Avanzate; Napoli Italy
| | - Roberta Russo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II; Napoli Italy
- CEINGE Biotecnologie Avanzate; Napoli Italy
| | - Antonella Gambale
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II; Napoli Italy
- CEINGE Biotecnologie Avanzate; Napoli Italy
| | - Achille Iolascon
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II; Napoli Italy
- CEINGE Biotecnologie Avanzate; Napoli Italy
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28
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Abstract
The erythrocyte contains a network of pathways that regulate salt and water content in the face of extracellular and intracellular osmotic perturbations. This allows the erythrocyte to maintain a narrow range of cell hemoglobin concentration, a process critical for normal red blood cell function and survival. Primary disorders that perturb volume homeostasis jeopardize the erythrocyte and may lead to its premature destruction. These disorders are marked by clinical, laboratory, and physiologic heterogeneity. Recent studies have revealed that these disorders are also marked by genetic heterogeneity. They have implicated roles for several proteins, PIEZO1, a mammalian mechanosensory protein; GLUT1, the glucose transporter; SLC4A1, the anion transporter; RhAG, the Rh-associated glycoprotein; KCNN4, the Gardos channel; and ABCB6, an adenosine triphosphate-binding cassette family member, in the maintenance of erythrocyte volume homeostasis. Secondary disorders of erythrocyte hydration include sickle cell disease, thalassemia, hemoglobin CC, and hereditary spherocytosis, where cellular dehydration may be a significant contributor to disease pathology and clinical complications. Understanding the pathways regulating erythrocyte water and solute content may reveal innovative strategies to maintain normal volume in disorders associated with primary or secondary cellular dehydration. These mechanisms will serve as a paradigm for other cells and may reveal new therapeutic targets for disease prevention and treatment beyond the erythrocyte.
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29
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Pucciarelli V, Bertoli S, Codari M, De Amicis R, De Giorgis V, Battezzati A, Veggiotti P, Sforza C. The face of Glut1-DS patients. Clin Anat 2017; 30:644-652. [DOI: 10.1002/ca.22890] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 04/21/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Valentina Pucciarelli
- LAFAS, Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano; Italy
| | - Simona Bertoli
- Dipartimento di Scienze per gli Alimenti; la Nutrizione e l'Ambiente, Università degli Studi di Milano; Milano Italy
| | - Marina Codari
- Unit of Radiology, IRCCS Policlinico San Donato; San Donato Milanese Milan Italy
| | - Ramona De Amicis
- Dipartimento di Scienze per gli Alimenti; la Nutrizione e l'Ambiente, Università degli Studi di Milano; Milano Italy
| | - Valentina De Giorgis
- Department of Child Neurology and Psychiatry; C. Mondino National Neurological Institute; Pavia Italy
| | - Alberto Battezzati
- Dipartimento di Scienze per gli Alimenti; la Nutrizione e l'Ambiente, Università degli Studi di Milano; Milano Italy
| | - Pierangelo Veggiotti
- Department of Child Neurology and Psychiatry; C. Mondino National Neurological Institute; Pavia Italy
- Brain and Behaviour Department; University of Pavia; Italy
| | - Chiarella Sforza
- LAFAS, Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico, Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano; Italy
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30
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Genetet S, Desrames A, Chouali Y, Ripoche P, Lopez C, Mouro-Chanteloup I. Stomatin modulates the activity of the Anion Exchanger 1 (AE1, SLC4A1). Sci Rep 2017; 7:46170. [PMID: 28387307 PMCID: PMC5383999 DOI: 10.1038/srep46170] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/09/2017] [Indexed: 12/17/2022] Open
Abstract
Anion Exchanger 1 (AE1) and stomatin are integral proteins of the red blood cell (RBC) membrane. Erythroid and kidney AE1 play a major role in HCO3- and Cl- exchange. Stomatins down-regulate the activity of many channels and transporters. Biochemical studies suggested an interaction of erythroid AE1 with stomatin. Moreover, we previously reported normal AE1 expression level in stomatin-deficient RBCs. Here, the ability of stomatin to modulate AE1-dependent Cl-/HCO3- exchange was evaluated using stopped-flow methods. In HEK293 cells expressing recombinant AE1 and stomatin, the permeabilities associated with AE1 activity were 30% higher in cells overexpressing stomatin, compared to cells with only endogenous stomatin expression. Ghosts from stomatin-deficient RBCs and controls were resealed in the presence of pH- or chloride-sensitive fluorescent probes and submitted to inward HCO3- and outward Cl- gradients. From alkalinization rate constants, we deduced a 47% decreased permeability to HCO3- for stomatin-deficient patients. Similarly, kinetics of Cl- efflux, followed by the probe dequenching, revealed a significant 42% decrease in patients. In situ Proximity Ligation Assays confirmed an interaction of AE1 with stomatin, in both HEK recombinant cells and RBCs. Here we show that stomatin modulates the transport activity of AE1 through a direct protein-protein interaction.
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Affiliation(s)
- Sandrine Genetet
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
| | - Alexandra Desrames
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
| | - Youcef Chouali
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
| | - Pierre Ripoche
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
| | - Claude Lopez
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
| | - Isabelle Mouro-Chanteloup
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75739 Paris Cedex 15, France
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31
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Andolfo I, Russo R, Gambale A, Iolascon A. New insights on hereditary erythrocyte membrane defects. Haematologica 2016; 101:1284-1294. [PMID: 27756835 PMCID: PMC5394881 DOI: 10.3324/haematol.2016.142463] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/16/2016] [Indexed: 01/02/2023] Open
Abstract
After the first proposed model of the red blood cell membrane skeleton 36 years ago, several additional proteins have been discovered during the intervening years, and their relationship with the pathogenesis of the related disorders have been somewhat defined. The knowledge of erythrocyte membrane structure is important because it represents the model for spectrin-based membrane skeletons in all cells and because defects in its structure underlie multiple hemolytic anemias. This review summarizes the main features of erythrocyte membrane disorders, dividing them into structural and altered permeability defects, focusing particularly on the most recent advances. New proteins involved in alterations of the red blood cell membrane permeability were recently described. The mechanoreceptor PIEZO1 is the largest ion channel identified to date, the fundamental regulator of erythrocyte volume homeostasis. Missense, gain-of-function mutations in the PIEZO1 gene have been identified in several families as causative of dehydrated hereditary stomatocytosis or xerocytosis. Similarly, the KCNN4 gene, codifying the so called Gardos channel, has been recently identified as a second causative gene of hereditary xerocytosis. Finally, ABCB6 missense mutations were identified in different pedigrees of familial pseudohyperkalemia. New genomic technologies have improved the quality and reduced the time of diagnosis of these diseases. Moreover, they are essential for the identification of the new causative genes. However, many questions remain to solve, and are currently objects of intensive studies.
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Affiliation(s)
- Immacolata Andolfo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Roberta Russo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Antonella Gambale
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Achille Iolascon
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Italy
- CEINGE Biotecnologie Avanzate, Napoli, Italy
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Musleh M, Ashworth J, Black G, Hall G. Improving diagnosis for congenital cataract by introducing NGS genetic testing. BMJ QUALITY IMPROVEMENT REPORTS 2016; 5:bmjqir.u211094.w4602. [PMID: 27933154 PMCID: PMC5128776 DOI: 10.1136/bmjquality.u211094.w4602] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/28/2016] [Indexed: 11/09/2022]
Abstract
Childhood cataract (CC) has an incidence of 3.5 per 10,000 by age 15 years. Diagnosis of any underlying cause is important to ensure effective and prompt management of multisystem complications, to facilitate accurate genetic counselling and to streamline multidisciplinary care. Next generation sequencing (NGS) has been shown to be effective in providing an underlying diagnosis in 70% of patients with CC in a research setting. This project aimed to integrate NGS testing in CC within six months of presentation and increase the rate of diagnosis. A retrospective case note review was undertaken to define the baseline efficacy of current care in providing a precise diagnosis. Quality improvement methods were used to integrate and optimize NGS testing in clinical care and measure the improvements made. The percentage of children receiving an NGS result within six months increased from 26% to 71% during the project period. The mean time to NGS testing and receiving a report decreased and there was a reduction in variation over the study period. Several patients and families had a change in management or genetic counselling as a direct result of the diagnosis given by the NGS test. The current recommended investigation of patients with bilateral CC is ineffective in identifying a diagnosis. Quality Improvement methods have facilitated successful integration of NGS testing into clinical care, improving time to diagnosis and leading to development of a new care pathway.
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33
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Huang S, Cao X, Tian X. Transcriptomic Analysis of Compromise Between Air-Breathing and Nutrient Uptake of Posterior Intestine in Loach (Misgurnus anguillicaudatus), an Air-Breathing Fish. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2016; 18:521-533. [PMID: 27457889 DOI: 10.1007/s10126-016-9713-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 05/31/2016] [Indexed: 06/06/2023]
Abstract
Dojo loach (Misgurnus anguillicaudatus) is an air-breathing fish species by using its posterior intestine to breathe on water surface. So far, the molecular mechanism about accessory air-breathing in fish is seldom addressed. Five cDNA libraries were constructed here for loach posterior intestines form T01 (the initial stage group), T02 (mid-stage of normal group), T03 (end stage of normal group), T04 (mid-stage of air-breathing inhibited group), and T05 (the end stage of air-breathing inhibited group) and subjected to perform RNA-seq to compare their transcriptomic profilings. A total of 92,962 unigenes were assembled, while 37,905 (40.77 %) unigenes were successfully annotated. 2298, 1091, and 3275 differentially expressed genes (fn1, ACE, EGFR, Pxdn, SDF, HIF, VEGF, SLC2A1, SLC5A8 etc.) were observed in T04/T02, T05/T03, and T05/T04, respectively. Expression levels of many genes associated with air-breathing and nutrient uptake varied significantly between normal and intestinal air-breathing inhibited group. Intraepithelial capillaries in posterior intestines of loaches from T05 were broken, while red blood cells were enriched at the surface of intestinal epithelial lining with 241 ± 39 cells per millimeter. There were periodic acid-schiff (PAS)-positive epithelial mucous cells in posterior intestines from both normal and air-breathing inhibited groups. Results obtained here suggested an overlap of air-breathing and nutrient uptake function of posterior intestine in loach. Intestinal air-breathing inhibition in loach would influence the posterior intestine's nutrient uptake ability and endothelial capillary structure stability. This study will contribute to our understanding on the molecular regulatory mechanisms of intestinal air-breathing in loach.
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Affiliation(s)
- Songqian Huang
- College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China
| | - Xiaojuan Cao
- College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China.
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Hubei, People's Republic of China.
- Hubei Provincial Engineering Laboratory for Pond Aquaculture, Hubei, People's Republic of China.
| | - Xianchang Tian
- College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China
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34
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Badens C, Guizouarn H. Advances in understanding the pathogenesis of the red cell volume disorders. Br J Haematol 2016; 174:674-85. [PMID: 27353637 DOI: 10.1111/bjh.14197] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Genetic defects of erythrocyte transport proteins cause disorders of red blood cell volume that are characterized by abnormal permeability to the cations Na(+) and K(+) and, consequently, by changes in red cell hydration. Clinically, these disorders are associated with chronic haemolytic anaemia of variable severity and significant co-morbidities, such as iron overload. This review provides an overview of recent insights into the molecular basis of this group of rare anaemias involving cation channels and transporters dysfunction. To date, a total of 5 different membrane proteins have been reported to be responsible for volume homeostasis alteration when mutated, 3 of them leading to overhydrated cells (AE1 [also termed SLC4A1], RHAG and GLUT1 [also termed SCL2A1) and 2 others to dehydrated cells (PIEZO1 and the Gardos Channel). These findings are not only of basic scientific interest, but also of direct clinical significance for improving diagnostic procedures and identify potential approaches for novel therapeutic strategies.
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Affiliation(s)
- Catherine Badens
- APHM Department of Medical Genetics, Hôpital de la Timone, Aix Marseille Univ, INSERM, GMGF, Marseille, France
| | - Hélène Guizouarn
- Univ. Nice Sophia Antipolis, CNRS, Inserm, iBV, 06100 Nice, France
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35
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Glogowska E, Gallagher PG. Disorders of erythrocyte volume homeostasis. Int J Lab Hematol 2016; 37 Suppl 1:85-91. [PMID: 25976965 DOI: 10.1111/ijlh.12357] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/13/2015] [Indexed: 01/18/2023]
Abstract
Inherited disorders of erythrocyte volume homeostasis are a heterogeneous group of rare disorders with phenotypes ranging from dehydrated to overhydrated erythrocytes. Clinical, laboratory, physiologic, and genetic heterogeneities characterize this group of disorders. A series of recent reports have provided novel insights into our understanding of the genetic bases underlying some of these disorders of red cell volume regulation. This report reviews this progress in understanding determinants that influence erythrocyte hydration and how they have yielded a better understanding of the pathways that influence cellular water and solute homeostasis.
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Affiliation(s)
- E Glogowska
- Departments of Pediatrics, Pathology and Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - P G Gallagher
- Departments of Pediatrics, Pathology and Genetics, Yale University School of Medicine, New Haven, CT, USA
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36
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Plasmodiumfalciparum infection induces dynamic changes in the erythrocyte phospho-proteome. Blood Cells Mol Dis 2016; 58:35-44. [PMID: 27067487 DOI: 10.1016/j.bcmd.2016.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 02/05/2016] [Indexed: 11/21/2022]
Abstract
The phosphorylation status of red blood cell proteins is strongly altered during the infection by the malaria parasite Plasmodium falciparum. We identify the key phosphorylation events that occur in the erythrocyte membrane and cytoskeleton during infection, by a comparative analysis of global phospho-proteome screens between infected (obtained at schizont stage) and uninfected RBCs. The meta-analysis of reported mass spectrometry studies revealed a novel compendium of 495 phosphorylation sites in 182 human proteins with regulatory roles in red cell morphology and stability, with about 25% of these sites specific to infected cells. A phosphorylation motif analysis detected 7 unique motifs that were largely mapped to kinase consensus sequences of casein kinase II and of protein kinase A/protein kinase C. This analysis highlighted prominent roles for PKA/PKC involving 78 phosphorylation sites. We then compared the phosphorylation status of PKA (PKC) specific sites in adducin, dematin, Band 3 and GLUT-1 in uninfected RBC stimulated or not by cAMP to their phosphorylation status in iRBC. We showed cAMP-induced phosphorylation of adducin S59 by immunoblotting and we were able to demonstrate parasite-induced phosphorylation for adducin S726, Band 3 and GLUT-1, corroborating the protein phosphorylation status in our erythrocyte phosphorylation site compendium.
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Engert A, Balduini C, Brand A, Coiffier B, Cordonnier C, Döhner H, de Wit TD, Eichinger S, Fibbe W, Green T, de Haas F, Iolascon A, Jaffredo T, Rodeghiero F, Salles G, Schuringa JJ. The European Hematology Association Roadmap for European Hematology Research: a consensus document. Haematologica 2016; 101:115-208. [PMID: 26819058 PMCID: PMC4938336 DOI: 10.3324/haematol.2015.136739] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 01/27/2016] [Indexed: 01/28/2023] Open
Abstract
The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap.The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders.The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.
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Affiliation(s)
| | | | - Anneke Brand
- Leids Universitair Medisch Centrum, Leiden, the Netherlands
| | | | | | | | | | | | - Willem Fibbe
- Leids Universitair Medisch Centrum, Leiden, the Netherlands
| | - Tony Green
- Cambridge Institute for Medical Research, United Kingdom
| | - Fleur de Haas
- European Hematology Association, The Hague, the Netherlands
| | | | | | | | - Gilles Salles
- Hospices Civils de Lyon/Université de Lyon, Pierre-Bénite, France
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Gillespie RL, Urquhart J, Anderson B, Williams S, Waller S, Ashworth J, Biswas S, Jones S, Stewart F, Lloyd IC, Clayton-Smith J, Black GC. Next-generation Sequencing in the Diagnosis of Metabolic Disease Marked by Pediatric Cataract. Ophthalmology 2016; 123:217-20. [DOI: 10.1016/j.ophtha.2015.06.035] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 06/19/2015] [Accepted: 06/19/2015] [Indexed: 11/17/2022] Open
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Andolfo I, Russo R, Manna F, Shmukler BE, Gambale A, Vitiello G, De Rosa G, Brugnara C, Alper SL, Snyder LM, Iolascon A. Novel Gardos channel mutations linked to dehydrated hereditary stomatocytosis (xerocytosis). Am J Hematol 2015; 90:921-6. [PMID: 26178367 DOI: 10.1002/ajh.24117] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 07/08/2015] [Indexed: 02/06/2023]
Abstract
Dehydrated hereditary stomatocytosis (DHSt) is an autosomal dominant congenital hemolytic anemia with moderate splenomegaly and often compensated hemolysis. Affected red cells are characterized by a nonspecific cation leak of the red cell membrane, reflected in elevated sodium content, decreased potassium content, elevated MCHC and MCV, and decreased osmotic fragility. The majority of symptomatic DHSt cases reported to date have been associated with gain-of-function mutations in the mechanosensitive cation channel gene, PIEZO1. A recent study has identified two families with DHSt associated with a single mutation in the KCNN4 gene encoding the Gardos channel (KCa3.1), the erythroid Ca(2+) -sensitive K(+) channel of intermediate conductance, also expressed in many other cell types. We present here, in the second report of DHSt associated with KCNN4 mutations, two previously undiagnosed DHSt families. Family NA exhibited the same de novo missense mutation as that recently described, suggesting a hot spot codon for DHSt mutations. Family WO carried a novel, inherited missense mutation in the ion transport domain of the channel. The patients' mild hemolytic anemia did not improve post-splenectomy, but splenectomy led to no serious thromboembolic events. We further characterized the expression of KCNN4 in the mutated patients and during erythroid differentiation of CD34+ cells and K562 cells. We also analyzed KCNN4 expression during mouse embryonic development.
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Affiliation(s)
- Immacolata Andolfo
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Roberta Russo
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Francesco Manna
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Boris E. Shmukler
- Renal Division And Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School; Boston Massachusetts
- Department Of Medicine, Harvard Medical School; Boston Massachusetts
| | - Antonella Gambale
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Giuseppina Vitiello
- Biotecnologie Avanzate; CEINGE; Naples Italy
- Medical Genetics Unit; Policlinico Tor Vergata University Hospital; Viale Oxford Rome Italy
| | - Gianluca De Rosa
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
| | - Carlo Brugnara
- Department Of Laboratory Medicine, Boston Children's Hospital And Department Of Pathology; Harvard Medical School; Boston Massachusetts
| | - Seth L. Alper
- Renal Division And Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School; Boston Massachusetts
| | - L. Michael Snyder
- Dept Of Hospital Laboratories; University Of Massachusetts Medical Center; Worcester MA
- Quest Diagnositics, LLC MA; Marlborough Massachusetts
| | - Achille Iolascon
- Department Of Molecular Medicine And Medical Biotechnologies; “Federico II” University Of Naples; Naples Italy
- Biotecnologie Avanzate; CEINGE; Naples Italy
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King MJ, Garçon L, Hoyer JD, Iolascon A, Picard V, Stewart G, Bianchi P, Lee SH, Zanella A. ICSH guidelines for the laboratory diagnosis of nonimmune hereditary red cell membrane disorders. Int J Lab Hematol 2015; 37:304-25. [PMID: 25790109 DOI: 10.1111/ijlh.12335] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/22/2015] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Hereditary spherocytosis (HS), hereditary elliptocytosis (HE), and hereditary stomatocytosis (HSt) are inherited red cell disorders caused by defects in various membrane proteins. The heterogeneous clinical presentation, biochemical and genetic abnormalities in HS and HE have been well documented. The need to raise the awareness of HSt, albeit its much lower prevalence than HS, is due to the undesirable outcome of splenectomy in these patients. METHODS The scope of this guideline is to identify the characteristic clinical features, the red cell parameters (including red cell morphology) for these red cell disorders associated, respectively, with defective cytoskeleton (HS and HE) and abnormal cation permeability in the lipid bilayer (HSt) of the red cell. The current screening tests for HS are described, and their limitations are highlighted. RESULTS An appropriate diagnosis can often be made when the screening test result(s) is reviewed together with the patient's clinical/family history, blood count results, reticulocyte count, red cell morphology, and chemistry results. SDS-polyacrylamide gel electrophoresis of erythrocyte membrane proteins, monovalent cation flux measurement, and molecular analysis of membrane protein genes are specialist tests for further investigation. CONCLUSION Specialist tests provide additional evidence in supporting the diagnosis and that will facilitate the management of the patient. In the case of a patient's clinical phenotype being more severe than the affected members within the immediate family, molecular testing of all family members is useful for confirming the diagnosis and allows an insight into the molecular basis of the abnormality such as a recessive mode of inheritance or a de novo mutation.
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Affiliation(s)
- M-J King
- Membrane Biochemistry, NHS Blood and Transplant, Bristol, UK
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41
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KLF1-null neonates display hydrops fetalis and a deranged erythroid transcriptome. Blood 2015; 125:2405-17. [PMID: 25724378 DOI: 10.1182/blood-2014-08-590968] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 02/21/2015] [Indexed: 12/14/2022] Open
Abstract
We describe a case of severe neonatal anemia with kernicterus caused by compound heterozygosity for null mutations in KLF1, each inherited from asymptomatic parents. One of the mutations is novel. This is the first described case of a KLF1-null human. The phenotype of severe nonspherocytic hemolytic anemia, jaundice, hepatosplenomegaly, and marked erythroblastosis is more severe than that present in congenital dyserythropoietic anemia type IV as a result of dominant mutations in the second zinc-finger of KLF1. There was a very high level of HbF expression into childhood (>70%), consistent with a key role for KLF1 in human hemoglobin switching. We performed RNA-seq on circulating erythroblasts and found that human KLF1 acts like mouse Klf1 to coordinate expression of many genes required to build a red cell including those encoding globins, cytoskeletal components, AHSP, heme synthesis enzymes, cell-cycle regulators, and blood group antigens. We identify novel KLF1 target genes including KIF23 and KIF11 which are required for proper cytokinesis. We also identify new roles for KLF1 in autophagy, global transcriptional control, and RNA splicing. We suggest loss of KLF1 should be considered in otherwise unexplained cases of severe neonatal NSHA or hydrops fetalis.
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Trakarnsanga K, Wilson MC, Griffiths RE, Toye AM, Carpenter L, Heesom KJ, Parsons SF, Anstee DJ, Frayne J. Qualitative and quantitative comparison of the proteome of erythroid cells differentiated from human iPSCs and adult erythroid cells by multiplex TMT labelling and nanoLC-MS/MS. PLoS One 2014; 9:e100874. [PMID: 25019302 PMCID: PMC4096399 DOI: 10.1371/journal.pone.0100874] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/31/2014] [Indexed: 01/01/2023] Open
Abstract
Induced pluripotent stem cells (iPSC) are an attractive progenitor source for the generation of in vitro blood products. However, before iPSC-derived erythroid cells can be considered for therapeutic use their similarity to adult erythroid cells must be confirmed. We have analysed the proteome of erythroid cells differentiated from the iPSC fibroblast derived line (C19) and showed they express hallmark RBC proteins, including all those of the ankyrin and 4.1R complex. We next compared the proteome of erythroid cells differentiated from three iPSC lines (C19, OCE1, OPM2) with that of adult and cord blood progenitors. Of the 1989 proteins quantified <3% differed in level by 2-fold or more between the different iPSC-derived erythroid cells. When compared to adult cells, 11% of proteins differed in level by 2-fold or more, falling to 1.9% if a 5-fold threshold was imposed to accommodate slight inter-cell line erythropoietic developmental variation. Notably, the level of >30 hallmark erythroid proteins was consistent between the iPSC lines and adult cells. In addition, a sub-population (10-15%) of iPSC erythroid cells in each of the iPSC lines completed enucleation. Aberrant expression of some cytoskeleton proteins may contribute to the failure of the majority of the cells to enucleate since we detected some alterations in cytoskeletal protein abundance. In conclusion, the proteome of erythroid cells differentiated from iPSC lines is very similar to that of normal adult erythroid cells, but further work to improve the induction of erythroid cells in existing iPSC lines or to generate novel erythroid cell lines is required before iPSC-derived red cells can be considered suitable for transfusion therapy.
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Affiliation(s)
- Kongtana Trakarnsanga
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
- Department of Biochemistry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Rebecca E. Griffiths
- Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), Filton, Bristol, United Kingdom
| | - Ashley M. Toye
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
- Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), Filton, Bristol, United Kingdom
| | - Lee Carpenter
- Blood Research Laboratory, National Health Service Blood and Transplant, John Radcliffe Hospital, Oxford, United Kingdom
| | - Kate J. Heesom
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Steve F. Parsons
- Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), Filton, Bristol, United Kingdom
| | - David J. Anstee
- Bristol Institute for Transfusion Sciences, National Health Service Blood and Transplant (NHSBT), Filton, Bristol, United Kingdom
| | - Jan Frayne
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
- * E-mail:
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Bawazir WM, Flatt JF, Wallis JP, Rendon A, Cardigan RA, New HV, Wiltshire M, Page L, Chapman CE, Stewart GW, Bruce LJ. Familial pseudohyperkalemia in blood donors: a novel mutation with implications for transfusion practice. Transfusion 2014; 54:3043-50. [PMID: 24947683 DOI: 10.1111/trf.12757] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/07/2014] [Accepted: 05/13/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Familial pseudohyperkalemia (FP) is a dominantly inherited condition in which red blood cells (RBCs) have an increased cold-induced permeability to monovalent cations. Potassium leaks into the supernatant of all stored blood with time, but FP RBCs leak potassium more rapidly. We investigated two unrelated blood donors whose RBC donations demonstrated unexpectedly high potassium after 5 and 6 days' storage. We matched the observed pattern of RBC cation leak to a previously recognized family with FP (FP-Cardiff) and investigated the likely cause with targeted DNA analysis. STUDY DESIGN AND METHODS Cation leakage from the donor RBCs and from standard donor units was measured. DNA analysis of donors and family members with FP-Cardiff was performed. Allele frequencies were obtained from human variation databases. RESULTS Both implicated donors were found to have increased cold-induced potassium leak identical in pattern to affected members of the family with FP-Cardiff. We found a heterozygous substitution Arg723Gln in the ATP-binding cassette, Subfamily B, Member 6 protein that segregated with FP in the Cardiff family and was also present in both blood donors. Arg723Gln is listed in human variation databases with an allele frequency of approximately 1:1000. CONCLUSIONS We describe a novel FP mutation that may affect 1:500 European blood donors and causes rapid loss of potassium from stored RBCs. This finding has implications for neonates and infants receiving large-volume RBC transfusions. Genomic screening of donors could be used to identify donors with this mutation and potentially improve the quality and safety of donor units.
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Affiliation(s)
- Waleed M Bawazir
- Bristol Institute for Transfusion Sciences, NHS Blood & Transplant, Bristol, UK; School of Biochemistry, University of Bristol, Bristol, UK
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Klepper J. Glucide metabolism disorders (excluding glycogen myopathies). HANDBOOK OF CLINICAL NEUROLOGY 2014; 113:1689-94. [PMID: 23622389 DOI: 10.1016/b978-0-444-59565-2.00036-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Glucide metabolism comprises pathways for transport, intermediate metabolism, utilization, and storage of carbohydrates. Defects affect multiple organs and present as systemic diseases. Neurological symptoms result from hypoglycemia, lactic acidosis, or inadequate storage of complex glucide molecules in neurological tissues. In glycogen storage disorders hypoglycemia indicates hepatic involvement, weakness and muscle cramps muscle involvement. Hypoglycemia is also the leading neurological symptom in disorders of gluconeogenesis. Disorders of galactose and fructose metabolism are rare, detectable by neonatal screening, and manifest following dietary intake of these sugars. Rare defects within the pentose metabolism constitute a new area of inborn metabolic disorders and may present with neurological symptoms. Treatment of these disorders involves the avoidance of fasting, dietary treatment eliminating specific carbohydrates, and enzyme replacement therapy in individual glycogen storage diseases.GLUT1 deficiency syndrome, a specific disorder of glucose transport into brain, results in global developmental delay, early-onset epilepsy, and a complex movement disorder. Treatment with a high-fat, low-carbohydrate ketogenic diet provides ketones as an alternative fuel to the brain and restores brain energy metabolism. Recently paroxysmal exertion-induced dyskinesia and stomatin-deficient cryohydrocytosis have been identified as an allelic disorder to GLUT1 deficiency equally responding to a ketogenic diet.
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Affiliation(s)
- Joerg Klepper
- Children's Hospital Aschaffenburg, Aschaffenburg, Germany.
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45
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Leen WG, Taher M, Verbeek MM, Kamsteeg EJ, van de Warrenburg BP, Willemsen MA. GLUT1 deficiency syndrome into adulthood: a follow-up study. J Neurol 2014; 261:589-99. [PMID: 24413642 DOI: 10.1007/s00415-014-7240-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/30/2013] [Accepted: 01/01/2014] [Indexed: 10/25/2022]
Abstract
GLUT1 deficiency syndrome (GLUT1DS) is a treatable neurometabolic disorder in which glucose transport into the brain is disturbed. Besides the classic phenotype of intellectual disability, epilepsy, and movement disorders, other phenotypes are increasingly recognized. These include, for example, idiopathic generalized epilepsy and paroxysmal exercise-induced dyskinesia. Since the disorder has only been recognized for two decades and is mostly diagnosed in children, little is known about the disease course. Our purpose was to investigate the disease course of GLUT1DS patients with the classic, complex phenotype from infancy into adulthood. We performed a systematic literature review as well as a cohort study, including GLUT1DS patients aged 18 years and older. The literature search yielded a total of 91 adult GLUT1DS patients, of which 33 patients (one-third) had a complex phenotype. The cohort study included seven GLUT1DS patients with a complex phenotype who were prospectively followed up in our clinic from childhood into adulthood. Our results show that epilepsy is a prominent feature during childhood in classic GLUT1DS patients. During adolescence, however, epilepsy diminishes or even disappears, but new paroxysmal movement disorders, especially paroxysmal exercise-induced dyskinesia, either appear or worsen if already present in childhood. Intellectual disability was not systematically assessed, but cognitive functions appeared to be stabile throughout life. Like children, adolescents may benefit from a ketogenic diet or variants thereof.
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Affiliation(s)
- W G Leen
- Department of Neurology, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, 935 Neurology, PO BOX 9101, 6500 HB, Nijmegen, The Netherlands,
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46
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Alaarg A, Schiffelers RM, van Solinge WW, van Wijk R. Red blood cell vesiculation in hereditary hemolytic anemia. Front Physiol 2013; 4:365. [PMID: 24379786 PMCID: PMC3862113 DOI: 10.3389/fphys.2013.00365] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/25/2013] [Indexed: 12/14/2022] Open
Abstract
Hereditary hemolytic anemia encompasses a heterogeneous group of anemias characterized by decreased red blood cell survival because of inherited membrane, enzyme, or hemoglobin disorders. Affected red blood cells are more fragile, less deformable, and more susceptible to shear stress and oxidative damage, and show increased vesiculation. Red blood cells, as essentially all cells, constitutively release phospholipid extracellular vesicles in vivo and in vitro in a process known as vesiculation. These extracellular vesicles comprise a heterogeneous group of vesicles of different sizes and intracellular origins. They are described in literature as exosomes if they originate from multi-vesicular bodies, or as microvesicles when formed by a one-step budding process directly from the plasma membrane. Extracellular vesicles contain a multitude of bioactive molecules that are implicated in intercellular communication and in different biological and pathophysiological processes. Mature red blood cells release in principle only microvesicles. In hereditary hemolytic anemias, the underlying molecular defect affects and determines red blood cell vesiculation, resulting in shedding microvesicles of different compositions and concentrations. Despite extensive research into red blood cell biochemistry and physiology, little is known about red cell deformability and vesiculation in hereditary hemolytic anemias, and the associated pathophysiological role is incompletely assessed. In this review, we discuss recent progress in understanding extracellular vesicles biology, with focus on red blood cell vesiculation. Also, we review recent scientific findings on the molecular defects of hereditary hemolytic anemias, and their correlation with red blood cell deformability and vesiculation. Integrating bio-analytical findings on abnormalities of red blood cells and their microvesicles will be critical for a better understanding of the pathophysiology of hereditary hemolytic anemias.
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Affiliation(s)
- Amr Alaarg
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht Utrecht, Netherlands ; Department of Pharmaceutical Sciences, Utrecht University Utrecht, Netherlands
| | - Raymond M Schiffelers
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht Utrecht, Netherlands ; Department of Pharmaceutical Sciences, Utrecht University Utrecht, Netherlands
| | - Wouter W van Solinge
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht Utrecht, Netherlands
| | - Richard van Wijk
- Department of Clinical Chemistry and Haematology, University Medical Center Utrecht Utrecht, Netherlands
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47
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GLUT1 deficiency syndrome 2013: Current state of the art. Seizure 2013; 22:803-11. [DOI: 10.1016/j.seizure.2013.07.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 07/02/2013] [Accepted: 07/03/2013] [Indexed: 01/01/2023] Open
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48
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GLUT1 deficiency syndrome: an update. Rev Neurol (Paris) 2013; 170:91-9. [PMID: 24269118 DOI: 10.1016/j.neurol.2013.09.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/01/2013] [Accepted: 09/02/2013] [Indexed: 01/31/2023]
Abstract
INTRODUCTION Glucose transporter type 1 deficiency syndrome is caused by heterozygous, mostly de novo, mutations in the SLC2A1 gene encoding the glucose transporter GLUT1. Mutations in this gene limit brain glucose availability and lead to cerebral energy deficiency. STATE OF THE ART The phenotype is characterized by the variable association of mental retardation, acquired microcephaly, complex motor disorders, and paroxysmal manifestations including seizures and non-epileptic paroxysmal episodes. Clinical severity varies from mild motor dysfunction to severe neurological disability. In patients with mild phenotypes, paroxysmal manifestations may be the sole manifestations of the disease. In particular, the diagnosis should be considered in patients with paroxysmal exercise-induced dyskinesia or with early-onset generalized epilepsy. Low CSF level of glucose, relative to blood level, is the best biochemical clue to the diagnosis although not constantly found. Molecular analysis of the SLC2A1 gene confirms the diagnosis. Ketogenic diet is the cornerstone of the treatment and implicates a close monitoring by a multidisciplinary team including trained dieticians. Non-specific drugs may be used as add-on symptomatic treatments but their effects are often disappointing. CONCLUSION Glucose transporter type 1 deficiency syndrome is likely under diagnosed due to its complex and pleiotropic phenotype. Proper identification of the affected patients is important for clinical practice since the disease is treatable.
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Yokoyama H, Kobayashi D, Takizawa N, Fujii S, Matsui I. Structural and biochemical analysis of a thermostable membrane-bound stomatin-specific protease. JOURNAL OF SYNCHROTRON RADIATION 2013; 20:933-937. [PMID: 24121343 PMCID: PMC3795559 DOI: 10.1107/s0909049513021328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 07/31/2013] [Indexed: 06/02/2023]
Abstract
Membrane-bound proteases are involved in various regulatory functions. The N-terminal region of PH1510p (1510-N) from the hyperthermophilic archaeon Pyrococcus horikoshii is a serine protease with a catalytic Ser-Lys dyad (Ser97 and Lys138), and specifically cleaves the C-terminal hydrophobic region of the p-stomatin PH1511p. In a form of human hemolytic anemia known as hereditary stomatocytosis, the stomatin protein is deficient in the erythrocyte membrane due to mis-trafficking. In order to understand the catalytic mechanism of 1510-N in more detail, here the structural and biochemical analysis of 1510-N is reported. Two degraded products were produced via acyl-enzyme intermediates. 1510-N is a thermostable protease, and thus crystallization after heat treatment of the protease-peptide complex was attempted in order to understand the catalytic mechanism of 1510-N. The structure after heat treatment is almost identical to that with no heat treatment. According to the superposition between the structures with heat treatment and with no heat treatment, the N-terminal half of the peptide is superposed well, whereas the C-terminal half of the peptide is slightly deviated. The N-terminal half of the peptide binds to 1510-N more tightly than the C-terminal half of the peptide. The flexible L2 loops of 1510-N cover the peptide, and are involved in the protease activity.
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Affiliation(s)
- Hideshi Yokoyama
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Daisuke Kobayashi
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Naoto Takizawa
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Satoshi Fujii
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ikuo Matsui
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
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Abstract
PURPOSE OF REVIEW Regulation of erythrocyte volume homeostasis is critical for survival of the erythrocyte. Inherited or acquired disorders that perturb this homeostasis jeopardize the erythrocyte, leading to its premature destruction. This report reviews recent insights into pathways that influence cellular water and solute homeostasis and cell volume. RECENT FINDINGS The molecular and genetic bases of primary disorders of erythrocyte hydration are beginning to be revealed. Recent studies have implicated roles for a new protein PIEZO1, a long sought after mammalian mechanosensory protein; GLUT1, the glucose transporter; SLC4A1, the anion transporter; RhAG, the Rh-associated glycoprotein; and ABCB6, an ATP-binding cassette family member. Secondary disorders associated with perturbed cellular volume and volume regulation include sickle cell disease, thalassemia, and hereditary spherocytosis, in which dehydration contributes to disease pathology and clinical complications. Advances in understanding the mechanisms regulating erythrocyte solute and water content, particularly associated with mechanotransduction pathways, have revealed novel mechanisms controlling erythrocyte hydration. Understanding these processes may provide innovative strategies to maintain normal erythrocyte volume in disorders associated with primary or secondary cellular dehydration. SUMMARY Understanding the mechanisms controlling erythrocyte volume regulation will serve as a paradigm for other cells and may reveal new therapeutic targets for disease prevention and treatment.
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