Mild spherocytic hereditary elliptocytosis and altered levels of α- and γ-adducins in β-adducin-deficient mice

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3978-3985 ◽  
Author(s):  
Andrés F. Muro ◽  
Martı́n L. Marro ◽  
Srećko Gajović ◽  
Fabiola Porro ◽  
Lucio Luzzatto ◽  
...  
Keyword(s):  
Membrane Surface ◽  
Osmotic Fragility ◽  
Membrane Skeleton ◽  
Blood Film ◽  
Mean Corpuscular Hemoglobin ◽  
Messenger Rnas ◽  
Inherited Disorders ◽  
Erythrocyte Morphology ◽  
Mild Phenotype ◽  
Hereditary Elliptocytosis

The membrane skeleton, a dynamic network of proteins associated with the plasma membrane, determines the shape and mechanical properties of erythrocytes. Deficiencies or defects in membrane skeletal proteins are associated with inherited disorders of erythrocyte morphology and function. Adducin is one of the proteins localized at the spectrin-actin junction of the membrane skeleton. In this work we show that deficiency of β-adducin produces an 80% decrease of -adducin and a fourfold up-regulation of γ-adducin in erythrocytes. β-Adducin or any other isoform generated by translation of abnormally spliced messenger RNAs could not be detected by our antibodies either in ghosts or in cytoplasm of −/− erythrocytes. Actin levels were diminished in mutant mice, suggesting alterations in the actin-spectrin junctional complexes due to the absence of adducin. Elliptocytes, ovalocytes, and occasionally spherocytes were found in the blood film of −/− mice. Hematological values showed an increase in reticulocyte counts and mean corpuscular hemoglobin concentration, decreased mean corpuscular volume and hematocrit, and normal erythrocyte counts that, associated to splenomegaly, indicate that the mice suffer from mild anemia with compensated hemolysis. These modifications are due to a loss of membrane surface and dehydration that result in an increase in the osmotic fragility of red blood cells. The marked alteration in osmotic fragility together with the predominant presence of elliptocytes is reminiscent of the human disorder called spherocytic hereditary elliptocytosis. Our results suggest that the amount of adducin remaining in the mutant animals (presumably γ adducin) could be functional and might account for the mild phenotype.

Mild spherocytic hereditary elliptocytosis and altered levels of α- and γ-adducins in β-adducin-deficient mice

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3978-3985 ◽  
Author(s):  
Andrés F. Muro ◽  
Martı́n L. Marro ◽  
Srećko Gajović ◽  
Fabiola Porro ◽  
Lucio Luzzatto ◽  
...  
Keyword(s):  
Membrane Surface ◽  
Osmotic Fragility ◽  
Membrane Skeleton ◽  
Blood Film ◽  
Mean Corpuscular Hemoglobin ◽  
Messenger Rnas ◽  
Inherited Disorders ◽  
Erythrocyte Morphology ◽  
Mild Phenotype ◽  
Hereditary Elliptocytosis

Abstract The membrane skeleton, a dynamic network of proteins associated with the plasma membrane, determines the shape and mechanical properties of erythrocytes. Deficiencies or defects in membrane skeletal proteins are associated with inherited disorders of erythrocyte morphology and function. Adducin is one of the proteins localized at the spectrin-actin junction of the membrane skeleton. In this work we show that deficiency of β-adducin produces an 80% decrease of -adducin and a fourfold up-regulation of γ-adducin in erythrocytes. β-Adducin or any other isoform generated by translation of abnormally spliced messenger RNAs could not be detected by our antibodies either in ghosts or in cytoplasm of −/− erythrocytes. Actin levels were diminished in mutant mice, suggesting alterations in the actin-spectrin junctional complexes due to the absence of adducin. Elliptocytes, ovalocytes, and occasionally spherocytes were found in the blood film of −/− mice. Hematological values showed an increase in reticulocyte counts and mean corpuscular hemoglobin concentration, decreased mean corpuscular volume and hematocrit, and normal erythrocyte counts that, associated to splenomegaly, indicate that the mice suffer from mild anemia with compensated hemolysis. These modifications are due to a loss of membrane surface and dehydration that result in an increase in the osmotic fragility of red blood cells. The marked alteration in osmotic fragility together with the predominant presence of elliptocytes is reminiscent of the human disorder called spherocytic hereditary elliptocytosis. Our results suggest that the amount of adducin remaining in the mutant animals (presumably γ adducin) could be functional and might account for the mild phenotype.

scholarly journals Disorders of the erythrocyte membrane

2015 ◽  
Vol 9 (4) ◽  
pp. 323
Author(s):  
Sophia Delicou ◽  
Aikaterini Xydaki ◽  
Chryssanthi Kontaxi ◽  
Konstantinos Maragkos
Keyword(s):  
Surface Area ◽  
Erythrocyte Membrane ◽  
Structural Integrity ◽  
Mechanical Stability ◽  
Hereditary Spherocytosis ◽  
Membrane Surface ◽  
Membrane Skeleton ◽  
Inherited Disorders ◽  
Hereditary Elliptocytosis ◽  
Area Loss

Hemolytic anemia due to abnormalities of the erythrocyte membrane comprises an important group of inherited disorders. These include hereditary spherocytosis, hereditary elliptocytosis, hereditary pyropoikilocytosis, and the hereditary stomatocytosis syndromes. The erythrocyte membrane skeleton composed of spectrin, actin, and several other proteins is essential for the maintenance of the erythrocyte shape, reversible deformability, and membrane structural integrity in addition to controlling the lateral mobility of integral membrane proteins. These disorders are characterized by clinical and laboratory heterogeneity and, as evidenced by recent molecular studies, by genetic heterogeneity. Defects in various proteins involved in linking the lipid bilayer to membrane skeleton result in loss in membrane cohesion leading to surface area loss and hereditary spherocytosis while defects in proteins involved in lateral interactions of the spectrin-based skeleton lead to decreased mechanical stability, membrane fragmentation and hereditary elliptocytosis. The disease severity is primarily dependent on the extent of membrane surface area loss. Treatment with splenectomy is curative in most patients.

Hereditary elliptocytosis due to both qualitative and quantitative defects in membrane skeletal protein 4.1

Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2438-2443 ◽  
Author(s):  
JG Conboy ◽  
R Shitamoto ◽  
M Parra ◽  
R Winardi ◽  
A Kabra ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mechanical Stability ◽  
Membrane Skeleton ◽  
Actin Binding ◽  
Erythrocyte Morphology ◽  
Protein 4.1 ◽  
Hereditary Elliptocytosis ◽  
Exon Expression ◽  
Amino Acid Peptide ◽  
Skeletal Protein

Abstract Protein 4.1 is an important structural component of the membrane skeleton that helps determine erythrocyte morphology and membrane mechanical properties. In a previous study we identified a case of human hereditary elliptocytosis (HE) in which decreased membrane mechanical stability was due to deletion of 80 amino acids encompassing the entire 10-Kd spectrin-actin binding domain. A portion of this domain (21 amino acids) is encoded by an alternatively spliced exon that is expressed in late but not early erythroid cells. We now report a case of canine HE in which the abnormal phenotype is caused by failure to express this alternative peptide in the mature red blood cell (RBC) membrane skeleton, in conjunction with quantitative deficiency of protein 4.1. Western blotting of RBC membranes from a dog with HE showed a truncated protein 4.1 that did not react with antibodies directed against the alternative peptide. In addition, sequencing of cloned reticulocyte protein 4.1 cDNA showed a precise deletion of 63 nucleotides comprising this exon. Normal dog reticulocytes did express this exon. Expression of this 21 amino acid peptide during erythroid maturation is therefore essential for proper assembly of a mechanically competent membrane skeleton, because RBCs lacking this peptide have unstable membranes.

scholarly journals Hereditary elliptocytosis due to both qualitative and quantitative defects in membrane skeletal protein 4.1

Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2438-2443
Author(s):  
JG Conboy ◽  
R Shitamoto ◽  
M Parra ◽  
R Winardi ◽  
A Kabra ◽  
...  
Keyword(s):  
Amino Acids ◽  
Mechanical Stability ◽  
Membrane Skeleton ◽  
Actin Binding ◽  
Erythrocyte Morphology ◽  
Protein 4.1 ◽  
Hereditary Elliptocytosis ◽  
Exon Expression ◽  
Amino Acid Peptide ◽  
Skeletal Protein

Protein 4.1 is an important structural component of the membrane skeleton that helps determine erythrocyte morphology and membrane mechanical properties. In a previous study we identified a case of human hereditary elliptocytosis (HE) in which decreased membrane mechanical stability was due to deletion of 80 amino acids encompassing the entire 10-Kd spectrin-actin binding domain. A portion of this domain (21 amino acids) is encoded by an alternatively spliced exon that is expressed in late but not early erythroid cells. We now report a case of canine HE in which the abnormal phenotype is caused by failure to express this alternative peptide in the mature red blood cell (RBC) membrane skeleton, in conjunction with quantitative deficiency of protein 4.1. Western blotting of RBC membranes from a dog with HE showed a truncated protein 4.1 that did not react with antibodies directed against the alternative peptide. In addition, sequencing of cloned reticulocyte protein 4.1 cDNA showed a precise deletion of 63 nucleotides comprising this exon. Normal dog reticulocytes did express this exon. Expression of this 21 amino acid peptide during erythroid maturation is therefore essential for proper assembly of a mechanically competent membrane skeleton, because RBCs lacking this peptide have unstable membranes.

The membrane skeleton of acetylcholine receptor domains in rat myotubes contains antiparallel homodimers of beta-spectrin in filaments quantitatively resembling those of erythrocytes

1995 ◽  
Vol 108 (9) ◽  
pp. 3145-3154 ◽  
Author(s):  
D.W. Pumplin
Keyword(s):  
Monoclonal Antibody ◽  
Acetylcholine Receptor ◽  
Acetylcholine Receptors ◽  
Cytoplasmic Membrane ◽  
Membrane Surface ◽  
Membrane Skeleton ◽  
Immunogold Labeling ◽  
Platinum Coating ◽  
High Concentrations ◽  
Receptor Clusters

I used immunogold labeling and quick-freeze, deep-etch, rotary replication to characterize the membrane skeleton at regions with high concentrations of acetylcholine receptor domains in receptor clusters of cultured rat muscle cells. This membrane skeleton consists of a network of filaments closely applied to the cytoplasmic membrane surface. The filaments are specifically decorated by immunogold labeling with a monoclonal antibody, VIIF7, that recognizes an isoform of beta-spectrin colocalizing with acetylcholine receptors. The filaments are 32 +/- 11 nm in length and three to four filaments (average 3.1-3.3) join at each intersection to form the network. These parameters are nearly identical to those reported previously for the membrane skeleton of erythrocytes. Depending on the amount of platinum coating, filament diameters range from 9 to 11 nm in diameter, and are 1.4 nm larger on average than spectrin filaments of erythrocytes replicated at the same time. Filaments are decorated with gold particles close to one end, consistent with the location of the epitope recognized by the monoclonal antibody. Computer modeling shows that all filament intersections in the membrane skeletal network are equally capable of being labeled by the monoclonal antibody. This pattern of labeling is consistent with a network containing antiparallel homodimers of beta-spectrin.

scholarly journals Anion Exchanger 1 (Band 3) Is Required to Prevent Erythrocyte Membrane Surface Loss but Not to Form the Membrane Skeleton

Cell ◽  
1996 ◽  
Vol 86 (6) ◽  
pp. 917-927 ◽  
Author(s):  
Luanne L Peters ◽  
Ramesh A Shivdasani ◽  
Shih-Chun Liu ◽  
Manjit Hanspal ◽  
Kathryn M John ◽  
...  
Keyword(s):  
Erythrocyte Membrane ◽  
Anion Exchanger ◽  
Membrane Surface ◽  
Membrane Skeleton ◽  
Band 3 ◽  
Anion Exchanger 1 ◽  
Surface Loss

Targeted Deletion of γ-Adducin in Mice.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1723-1723
Author(s):  
Kenneth E. Sahr ◽  
Amy J. Lambert ◽  
Steven L. Ciciotte ◽  
Luanne L. Peters
Keyword(s):  
Western Blotting ◽  
Peripheral Blood ◽  
Osmotic Fragility ◽  
Membrane Skeleton ◽  
Red Cells ◽  
Null Mouse ◽  
Exon 2 ◽  
Rbc Membrane ◽  
Blood Smears ◽  
Peripheral Blood Smears

Abstract The adducins are a family of three closely related proteins (α, β, γ) encoded by distinct genes. α- and γ-adducin are expressed ubiquitously, while β expression is restricted to hematopoietic cells and the brain. In red blood cells (RBCs) adducin localizes to spectrin-actin junctions in the membrane skeleton as αβ heterotetramers. Previously (Gilligan et. al., PNAS, 1999) we showed that deletion of β-adducin results in osmotically fragile, microcytic RBCs and an overall phenotype of hereditary spherocytosis (HS). Notably, α-adducin was significantly reduced in β-adducin null RBCs. We also demonstrated that γ-adducin is present in low amounts in normal mouse RBCs and is upregulated ∼5-fold in β-adducin null RBCs. The increase in γ-adducin suggests that αγ heterotetramers may be compensating for the absence of β-adducin. In an effort to analyze γ-adducin function in RBCs in greater detail, we generated a conditional γ-adducin knockout allele in mice using a Cre-loxP strategy to delete exon 2 containing the start codon. All mice were maintained on a segregating B6.129 genetic background. Western blotting confirmed the absence of γ-adducin in spleen homogenates and RBC ghost preparations from γ-adducin null mice. All other membrane skeleton proteins examined by a combination of SDS-PAGE and western blotting, including α- and β-adducin, are normal in γ-adducin null RBCs (spectrin, ankyrin, band 3, protein 4.1, protein 4.2, dematin). Phenotypically, γ-adducin null mice display normal growth curves and show no overt defects. γ-adducin null RBCs appear normal on Wright’s stained peripheral blood smears and by scanning electron microscopy (SEM). The RBC count, hemoglobin content, hematocrit, MCV, reticulocyte %, osmotic fragility, and all other hematopoietic parameters are normal in γ-adducin null mice vs. wildtype. The apparent compensation by γ-adducin in β-adducin null red cells previously observed was tested by intercrossing mice null for γ- and β-adducin to produce βγ null double homozygotes. The additional loss of γ-adducin did not exacerbate the β-adducin null RBC phenotype as judged by examination of peripheral blood smears and SEM. Moreover, RBC osmotic fragility and complete blood counts in βγ-adducin null mice did not differ from β-adducin null mice. Western blotting of RBC ghost proteins confirmed reduction of α-adducin to ∼20% of normal in β-adducin null mice, as previously described. Strikingly, α-adducin in βγ-null RBC ghosts is reduced to barely detectable levels (<5% of normal). These studies show that (1) loss of γ-adducin alone does not significantly impact RBC membrane skeleton structure and function; (2) α- and β-adducin are stable and present at normal levels in the absence of γ-adducin; (3) the loss of γ-adducin in β-adducin null mice does not further exacerbate the β-adducin null HS phenotype; (4) the exacerbated loss of α-adducin in βγ double null RBCs suggests that up-regulated γ-adducin in β-adducin null mice associates in some way with and stabilizes α-adducin in the RBC membrane, but is unable to compensate functionally for the loss of the β subunit. We conclude that the normal function and stable incorporation of adducin into the peripheral membrane skeleton of red cells requires the presence of heterologous αβ binding subunits. Additional studies of adducin null mouse models, including our recently generated α-adducin null strain, will be useful tools in defining adducin functions and interactions in multiple tissues and organs.

Deletion of the mouse α-globin regulatory element (HS −26) has an unexpectedly mild phenotype

Blood ◽  
2002 ◽  
Vol 100 (10) ◽  
pp. 3450-3456 ◽  
Author(s):  
Eduardo Anguita ◽  
Jacqueline A. Sharpe ◽  
Jacqueline A. Sloane-Stanley ◽  
Cristina Tufarelli ◽  
Douglas R. Higgs ◽  
...  
Keyword(s):  
Regulatory Element ◽  
Globin Gene ◽  
Mean Corpuscular Hemoglobin ◽  
Single Element ◽  
Surprising Result ◽  
Globin Genes ◽  
Mild Phenotype ◽  
Mild Disease ◽  
Expression Studies ◽  
High Level

Natural deletions of the region upstream of the human α-globin gene cluster, together with expression studies in cell lines and transgenic mice, identified a single element (HS −40) as necessary and perhaps sufficient for high-level expression of the α-globin genes. A similar element occupies the corresponding position upstream of the mouse (m) α-globin genes (mHS −26) and was thought to have similar functional properties. We knocked out mHS −26 by homologous recombination and observed the surprising result that instead of the expected severe α-thalassemia phenotype, the mice had a mild disease. Transcription levels of the mouse genes were reduced by about 50%, but homozygotes were healthy, with normal hemoglobin levels and only mild decreases in mean corpuscular volume and mean corpuscular hemoglobin. These results may indicate differences in the regulation of the α-globin clusters in mice and humans or that additionalcis-acting elements remain to be characterized in one or both clusters.

scholarly journals Hemoglobin profiles of siblings of thalassemia patients

2015 ◽  
Vol 55 (2) ◽  
pp. 70
Author(s):  
Muhammad Riza ◽  
Septin Widiretnani
Keyword(s):  
Thalassemia Major ◽  
Cross Sectional Study ◽  
Mean Corpuscular Hemoglobin ◽  
Carrier Status ◽  
Corpuscular Hemoglobin ◽  
Inherited Disorders ◽  
Cross Sectional ◽  
Hemoglobin E ◽  
History Of ◽  
Complete Blood Counts

Background Thalassemia and hemoglobinopathies are themost common inherited disorders in many areas of the world,including South East Asia. The siblings of thalassemia major is agroup of high risk to carry the gene of thalassemia. Determiningthe carrier is useful for early treatment planning and preventionto the next child.Objective To determine carrier status among siblings ofthalassemia patients using a capillary electrophoresis system.Methods A cross-sectional study on the siblings of thalassemiamajor patients was performed from January 2011 to February2012 at Dr. Moewardi Hospital. Complete blood counts wereperformed in the siblings. Subjects with mean corpuscular volume(MCV) <80 fl and mean corpuscular hemoglobin (MCH) <27pg were subjected to analize hemoglobin fraction by capillaryelectrophoresis.Results Of the 26 subjects, there were 12 males and 14 females.The mean age was 9.38 (SD 6.8) years (range 1 to 29 years). Fromthe siblings, 10 were identified as normal, 5 were identified as ßthalassemia carriers and 5 were hemoglobin E (HbE) carriers. Sixsiblings were diagnosed with ß thalassemia/ HbE.Conclusion There are high occurrence of the two common typesof thalassemia carriers (ß and HbE) in our small group of subjectswho had a family history of thalassemia. Most of the siblingsof thalassemia had low MCV and MCH. 

Sign in / Sign up

Export Citation Format

Share Document