scholarly journals Globin-chain specificity of oxidation-induced changes in red blood cell membrane properties

Blood ◽  
1992 ◽  
Vol 79 (6) ◽  
pp. 1586-1592 ◽  
Author(s):  
SL Schrier ◽  
N Mohandas
Keyword(s):  
Membrane Damage ◽  
Membrane Skeleton ◽  
Material Behavior ◽  
Membrane Properties ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Globin Chain ◽  
Globin Chains ◽  
Alpha Globin

Abstract We have previously shown that excess unpaired alpha- and beta-globin chains in severe alpha- and beta-thalassemia interacting with the membrane skeleton induce different changes in membrane properties of red blood cells (RBCs) in these two phenotypes. We suggest that these differences in membrane material behavior may reflect the specificity of the membrane damage induced by alpha- and beta-globin chains. To further explore this hypothesis, we sought in vitro models that induce similar membrane alterations in normal RBCs. We found that treatment of normal RBCs with phenylhydrazine produced rigid and mechanically unstable membranes in conjunction with selective association of oxidized alpha-globin chains with the membrane skeleton, features characteristic of RBCs in severe beta-thalassemia. Methylhydrazine, in contrast, induced selective association of oxidized beta-globin chains with the membrane skeleton and produced rigid but hyperstable membranes, features that mimicked those of RBCs in severe alpha- thalassemia. These findings suggest that consequences of oxidation induced by globin chains are quite specific in that those agents that cause alpha-globin chain accumulation at the membrane produce rigid but mechanically unstable membranes, whereas membrane accumulation of beta- globin chains results in rigid but mechanically stable membranes. These in vitro experiments lend further support to the hypothesis that membrane-associated alpha- and beta-chains induce oxidative damage to highly specific different skeletal components and that the specificity of this skeletal damage accounts for the differences in material membrane properties of these oxidatively attacked RBCs and perhaps of alpha- and beta-thalassemic RBCs as well.

scholarly journals Globin-chain specificity of oxidation-induced changes in red blood cell membrane properties

Blood ◽  
1992 ◽  
Vol 79 (6) ◽  
pp. 1586-1592 ◽  
Author(s):  
SL Schrier ◽  
N Mohandas
Keyword(s):  
Membrane Damage ◽  
Membrane Skeleton ◽  
Material Behavior ◽  
Membrane Properties ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Globin Chain ◽  
Globin Chains ◽  
Alpha Globin

We have previously shown that excess unpaired alpha- and beta-globin chains in severe alpha- and beta-thalassemia interacting with the membrane skeleton induce different changes in membrane properties of red blood cells (RBCs) in these two phenotypes. We suggest that these differences in membrane material behavior may reflect the specificity of the membrane damage induced by alpha- and beta-globin chains. To further explore this hypothesis, we sought in vitro models that induce similar membrane alterations in normal RBCs. We found that treatment of normal RBCs with phenylhydrazine produced rigid and mechanically unstable membranes in conjunction with selective association of oxidized alpha-globin chains with the membrane skeleton, features characteristic of RBCs in severe beta-thalassemia. Methylhydrazine, in contrast, induced selective association of oxidized beta-globin chains with the membrane skeleton and produced rigid but hyperstable membranes, features that mimicked those of RBCs in severe alpha- thalassemia. These findings suggest that consequences of oxidation induced by globin chains are quite specific in that those agents that cause alpha-globin chain accumulation at the membrane produce rigid but mechanically unstable membranes, whereas membrane accumulation of beta- globin chains results in rigid but mechanically stable membranes. These in vitro experiments lend further support to the hypothesis that membrane-associated alpha- and beta-chains induce oxidative damage to highly specific different skeletal components and that the specificity of this skeletal damage accounts for the differences in material membrane properties of these oxidatively attacked RBCs and perhaps of alpha- and beta-thalassemic RBCs as well.

Genetic Heterogeneity of Alpha - and Beta - Globin Mutations in a German Multiethnic Population Group

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 5185-5185
Author(s):  
Regine Grosse ◽  
Florian Oyen ◽  
Belinda Weber ◽  
Reinhard Schneppenheim
Keyword(s):  
Genetic Counseling ◽  
Conflicts Of Interest ◽  
Beta Thalassemia ◽  
Compound Heterozygous ◽  
Beta Globin ◽  
Globin Chain ◽  
Globin Chains ◽  
Hemoglobin C ◽  
Thalassemia Minor ◽  
Alpha Globin

Abstract Abstract 5185 Thalassemia syndromes are among the most common hereditary diseases worldwide and are widespread throughout the Mediterranean Region, Africa, the Middle East, India, Burma, the Southeast Asia and Indonesia. Similarly, hemoglobinopathies are common in different ethnic groups and mixed syndromes of Thalassemia and hemoglobinopathies exist. In this retrospective study we report the number and type of Thalassemia mutations and their combination with hemoglobinopathies detected mostly in individuals with a migration background now living in Germany. DNA samples were analyzed by polymerase chain reaction (PCR) and direct DNA-sequencing and additionally by multiplex ligation-dependent amplification (MRC-HOLLAND MLPA®). Mutations in one or both beta-globin chains were found in 77 patients. Most of these mutations were beta Thalassemia mutations, n=41 (Thalassemia minor n=33, Thalassemia major/intermedia n=7, homozygous Quin-Hai Hemoglobinopathy n=1). In 34 samples we found the hemoglobin S single base mutation c. 20A>T p. E7V, either alone or in combination with a hemoglobin C mutation c. 19G>A p. E7K or beta Thalassemia mutation (HbAS n=14, HbSS n=12, HbSC n=6, HbSThal n=2). In two patients we found only the hemoglobin C mutation by itself (HbAC n=1, HbCC n=1). In 52 samples we found mutations on the alpha-globin chains, most often the 3. 7KB deletion (n=27), followed by the SEA (n=4), the 20. 5 KB deletion (n=4), the 4. 2 KB deletion (n=4), the Dutch deletion (n=3) and alpha triplication (n=3). Two of the remaining seven samples showed new alpha Thalassemia mutations which have not been described yet. In an additional 34 DNA samples we found a combination of alpha- and beta-globin chain changes. In 4 of these samples we detected new mutations in the alpha-globin chains. The prevalence of mutations in the alpha- and beta-globin chains varies greatly because of a complex ethnic structure of our patients. Changes of the alpha-globin chains could not be safely detected by hemoglobin-electrophoresis. These situations are very important for genetic counseling in a population in which consanguineous marriages are common. Furthermore, alpha-globin mutations are genetic modifiers for beta Thalassemia and sickle cell disease and will influence the phenotype of beta-globin chain mutations. Patients with a compound heterozygous mutation for beta Thalassemia will probably not be detected by hemoglobin-electrophoresis alone, as in milder forms and early childhood the hemoglobin is not severely decreased and hemoglobin electrophoresis may be misinterpreted for Thalassemia minor. Our findings underline the heterogeneity of beta-globin and alpha-globin chain mutations and the importance of hematological and molecular analyses in the diagnosis and genetic counseling. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Characterization and comparison of the red blood cell membrane damage in severe human alpha- and beta-thalassemia

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 1058-1063 ◽  
Author(s):  
R Advani ◽  
S Sorenson ◽  
E Shinar ◽  
W Lande ◽  
E Rachmilewitz ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Membrane Damage ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Cell Membrane Damage ◽  
Protein 4.1 ◽  
Globin Chains ◽  
Alpha Thalassemia ◽  
Alpha Globin

Abstract The aim of the present work was to understand the pathophysiology of the severe human thalassemias as represented by beta-thalassemia intermedia and hemoglobin (Hb) H (alpha-thalassemia) disease. We have previously shown that the material properties of the red blood cell (RBC) and its membrane differ in severe alpha- and beta-thalassemia, and we now show that this difference is probably caused by accumulation of alpha-globin chains at the cytoskeleton in beta-thalassemia, whereas beta-globin chains are associated with the cytoskeleton in alpha- thalassemia. In both alpha- and beta-thalassemia, some of these globin chains have become oxidized as evidenced by loss of the free thiols. Furthermore, there is similar evidence of oxidation of protein 4.1 in beta-thalassemia, whereas beta-spectrin appears to be subject to oxidation in alpha-thalassemia. These observations support the idea that the association of partly oxidized globin chains with the cytoskeleton results in oxidation of adjacent skeletal proteins. The abnormality of protein 4.1 in beta-thalassemia is consistent with a prior observation, and is also in accord with the known importance of protein 4.1 in maintenance of membrane stability, a property that is abnormal in beta-thalassemic membranes.

scholarly journals Characterization and comparison of the red blood cell membrane damage in severe human alpha- and beta-thalassemia

Blood ◽  
1992 ◽  
Vol 79 (4) ◽  
pp. 1058-1063 ◽  
Author(s):  
R Advani ◽  
S Sorenson ◽  
E Shinar ◽  
W Lande ◽  
E Rachmilewitz ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Membrane Damage ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Cell Membrane Damage ◽  
Protein 4.1 ◽  
Globin Chains ◽  
Alpha Thalassemia ◽  
Alpha Globin

The aim of the present work was to understand the pathophysiology of the severe human thalassemias as represented by beta-thalassemia intermedia and hemoglobin (Hb) H (alpha-thalassemia) disease. We have previously shown that the material properties of the red blood cell (RBC) and its membrane differ in severe alpha- and beta-thalassemia, and we now show that this difference is probably caused by accumulation of alpha-globin chains at the cytoskeleton in beta-thalassemia, whereas beta-globin chains are associated with the cytoskeleton in alpha- thalassemia. In both alpha- and beta-thalassemia, some of these globin chains have become oxidized as evidenced by loss of the free thiols. Furthermore, there is similar evidence of oxidation of protein 4.1 in beta-thalassemia, whereas beta-spectrin appears to be subject to oxidation in alpha-thalassemia. These observations support the idea that the association of partly oxidized globin chains with the cytoskeleton results in oxidation of adjacent skeletal proteins. The abnormality of protein 4.1 in beta-thalassemia is consistent with a prior observation, and is also in accord with the known importance of protein 4.1 in maintenance of membrane stability, a property that is abnormal in beta-thalassemic membranes.

Alpha Hemoglobin Stabilizing Protein (AHSP) Optimizes Hemoglobin A Synthesis by Maintaining a Pool of Viable Alpha Globin Subunits.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 650-650
Author(s):  
Xiang Yu ◽  
Yi Kong ◽  
Louis C. Dore ◽  
Anne M. Katein ◽  
John K. Choi ◽  
...  
Keyword(s):  
In Vitro Translation ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Fully Depleted ◽  
Alpha Thalassemia ◽  
Gene Ablation ◽  
Mutant Strains ◽  
Alpha Globin

Abstract AHSP binds alpha hemoglobin (Hb) to maintain its structure and limit its prooxidant activities. In addition, AHSP binds and stabilizes apo-alpha globin, which lacks heme. Previously, we demonstrated that Ahsp−/− mice exhibit hemolytic anemia with Hb precipitation in erythroid cells. Through interbreeding of mutant strains, we also showed that loss of AHSP exacerbates beta thalassemia. Together, these studies indicate that AHSP participates in Hb homeostasis and may act to neutralize potentially toxic excess alpha globin that is known to accumulate in normal erythroid precursors, and to a greater extent, in beta thalassemic ones. However, additional functions for AHSP may exist. In particular, AHSP-alpha globin complexes may also promote HbA synthesis. To test this, we depleted the pool of excess alpha globin in Ahsp−/− mice by interbreeding with alpha thalassemic ones. Compared to mice with either mutation alone, compound mutants missing both AHSP and one alpha globin allele (genotype Ahsp−/− //alpha globin*α/αα) exhibited more severe erythroid defects, including worsened anemia, hypochromia, Hb instability and ineffective erythropoiesis. Pulse-labeling of double-mutant reticulocytes showed that alpha to beta globin synthetic ratios were unaffected by loss of AHSP, but precipitation of both alpha and beta nascent chains into cell membranes was strongly enhanced. These data indicate that AHSP is important for erythropoiesis and Hb production even when alpha globin is not produced in excess. In vitro translation studies using wheat germ extracts showed that recombinant AHSP present during the synthesis of alpha globin improved its ability to become incorporated into HbA. Moreover, AHSP conferred protease resistance to nascent alpha globin, suggesting enhanced folding into the native state. Further supporting this interpretation, circular dichroism studies showed that AHSP accelerated refolding of purified denatured alpha Hb. Finally, through pulse labeling of reticulocytes followed by isoelectric focusing of soluble cytosolic fractions, we identified transient pools of free alpha Hb and AHSP-alpha Hb in vivo and showed that Ahsp gene ablation fully depleted both pools. Together, our studies indicate that AHSP acts as a molecular chaperone to promote alpha globin folding and stability prior to its incorporation into HbA. In addition, it is possible that alterations in AHSP gene function or expression could modulate alpha thalassemia severity in patients.

scholarly journals The instability of the membrane skeleton in thalassemic red blood cells

Blood ◽  
1995 ◽  
Vol 86 (10) ◽  
pp. 3945-3950 ◽  
Author(s):  
J Yuan ◽  
A Bunyaratvej ◽  
S Fucharoen ◽  
C Fung ◽  
E Shinar ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Membrane Skeleton ◽  
Beta Thalassemia ◽  
Enzyme Linked Immunosorbent Assay ◽  
Beta Globin ◽  
Partial Explanation ◽  
Globin Chains

The thalassemias are a heterogeneous group of disorders characterized by accumulation either of unmatched alpha or beta globin chains. These in turn cause the intramedullary and peripheral hemolysis that leads to varying anemia. A partial explanation for the hemolysis came our of our studies on material properties that showed that beta-thalassemia (beta- thal) intermedia ghosts were very rigid but unstable. A clue to this instability came from the observation that the spectrin/band 3 ratio was low in red blood cells (RBCs) of splenectomized beta-thal intermedia patients. The possible explanations for the apparent decrease in spectrin content included deficient or defective spectrin synthesis in thalassemic erythroid precursors or globin chain-induced membrane changes that lead to spectrin dissociation from the membrane during ghost preparation. To explore the latter alternative, samples from different thalassemic variants were obtained, ie, beta-thal intermedia, HbE/beta-thal, HbH (alpha-thal-1/alpha-thal-2), HbH/Constant Spring (CS), and homozygous HbCS/CS. We searched for the presence of spectrin in the first lysate of the standard ghost preparation. Normal individuals and patients with autoimmune hemolytic anemia, sickle cell anemia, and anemia due to chemotherapy served as controls. Using gradient sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, no spectrin was detected in identical aliquots of the supernatants of normals and these control samples. Varying amounts of spectrin were detected in the first lysate supernatants of almost all thalassemic patients. The identification of spectrin was confirmed by Western blotting using an affinity-purified, monospecific, rabbit polyclonal antispectrin antibody. Relative amounts of spectrin detected were as follows in decreasing order: splenectomized beta-thal intermedia including HbE/beta-thal; HbCS/CS; nonsplenectomized beta-thal intermedia, HbH/CS; and, lastly, HbH. These findings were generally confirmed when we used an enzyme-linked immunosorbent assay technique to measure spectrin in the first lysate. Subsequent analyses showed that small amounts of actin and band 4.1 also appeared in lysates of thalassemic RBCs. Therefore, the three major membrane skeletal proteins are, to a varying degree, unstably attached in severe thalassemia. From these studies we could postulate that membrane association of abnormal or partially oxidized alpha- globin chains has a more deleterious effect on the membrane skeleton than do beta-globin chains.

scholarly journals Cellular and membrane properties of alpha and beta thalassemic erythrocytes are different: implication for differences in clinical manifestations

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2194-2202 ◽  
Author(s):  
SL Schrier ◽  
E Rachmilewitz ◽  
N Mohandas
Keyword(s):  
Cell Density ◽  
Mechanical Stability ◽  
Membrane Properties ◽  
Beta Thalassemia ◽  
Normal Density ◽  
Beta Globin ◽  
Globin Chains ◽  
Alpha Thalassemia ◽  
Dynamic Rigidity ◽  
Membrane Skeletons

To define how excess unpaired alpha- and beta-globin chains in severe beta-thalassemia and severe alpha-thalassemia interacting with the membrane might alter cellular and membrane properties, we performed a series of biophysical and biochemical analyses on erythrocytes obtained from affected patients. Detailed analysis of cellular and membrane deformability characteristics showed that both forms of thalassemic erythrocytes have excess surface area in relation to cell volume and increased membrane dynamic rigidity. The deformability characteristics of thalassemic erythrocytes in hypertonic media differed significantly from that of normal erythrocytes of identical cell density. These findings suggest that dynamic rigidity of thalassemic erythrocytes is influenced not only by cytoplasmic viscosity determined by cell hemoglobin concentration but also by the extent and type of globin interacting with the membrane. In contrast to the above-noted similarities, major differences were noted in the mechanical stability of the alpha- and beta-thalassemic membranes and in their state of cell hydration. While the mechanical stability of alpha-thalassemic membranes was normal or marginally elevated, the stability of beta- thalassemic membranes was markedly decreased to half the normal value. Cell-density analysis showed that the alpha-thalassemic erythrocytes were uniformly less dense than normal, while beta-thalassemic erythrocytes had a broad-density distribution, with all populations having both lower and higher than normal density values, implying cellular dehydration in beta-thalassemia and not in alpha-thalassemia. Membrane-protein analysis revealed that excess globin chains were bound to the membrane skeletons of both alpha- and beta-thalassemic erythrocytes, with the highest amounts being found in membrane skeletons derived from erythrocytes of splenectomized individuals with beta-thalassemia intermedia. These data demonstrate that interaction of excess alpha- and beta-globin chains with membranes produces different cellular changes and suggest that the observed differences in the pathophysiology of alpha- and beta-thalassemias may be related to different cellular effects induced by the excess in beta- and alpha- globin chains.

scholarly journals Cellular and membrane properties of alpha and beta thalassemic erythrocytes are different: implication for differences in clinical manifestations

Blood ◽  
1989 ◽  
Vol 74 (6) ◽  
pp. 2194-2202 ◽  
Author(s):  
SL Schrier ◽  
E Rachmilewitz ◽  
N Mohandas
Keyword(s):  
Cell Density ◽  
Mechanical Stability ◽  
Membrane Properties ◽  
Beta Thalassemia ◽  
Normal Density ◽  
Beta Globin ◽  
Globin Chains ◽  
Alpha Thalassemia ◽  
Dynamic Rigidity ◽  
Membrane Skeletons

Abstract To define how excess unpaired alpha- and beta-globin chains in severe beta-thalassemia and severe alpha-thalassemia interacting with the membrane might alter cellular and membrane properties, we performed a series of biophysical and biochemical analyses on erythrocytes obtained from affected patients. Detailed analysis of cellular and membrane deformability characteristics showed that both forms of thalassemic erythrocytes have excess surface area in relation to cell volume and increased membrane dynamic rigidity. The deformability characteristics of thalassemic erythrocytes in hypertonic media differed significantly from that of normal erythrocytes of identical cell density. These findings suggest that dynamic rigidity of thalassemic erythrocytes is influenced not only by cytoplasmic viscosity determined by cell hemoglobin concentration but also by the extent and type of globin interacting with the membrane. In contrast to the above-noted similarities, major differences were noted in the mechanical stability of the alpha- and beta-thalassemic membranes and in their state of cell hydration. While the mechanical stability of alpha-thalassemic membranes was normal or marginally elevated, the stability of beta- thalassemic membranes was markedly decreased to half the normal value. Cell-density analysis showed that the alpha-thalassemic erythrocytes were uniformly less dense than normal, while beta-thalassemic erythrocytes had a broad-density distribution, with all populations having both lower and higher than normal density values, implying cellular dehydration in beta-thalassemia and not in alpha-thalassemia. Membrane-protein analysis revealed that excess globin chains were bound to the membrane skeletons of both alpha- and beta-thalassemic erythrocytes, with the highest amounts being found in membrane skeletons derived from erythrocytes of splenectomized individuals with beta-thalassemia intermedia. These data demonstrate that interaction of excess alpha- and beta-globin chains with membranes produces different cellular changes and suggest that the observed differences in the pathophysiology of alpha- and beta-thalassemias may be related to different cellular effects induced by the excess in beta- and alpha- globin chains.

scholarly journals The inactive beta globin gene on a gamma delta beta thalassemia chromosome has a normal structure and functions normally in vitro

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 766-770
Author(s):  
PT Curtin ◽  
YW Kan
Keyword(s):  
Globin Gene ◽  
Large Deletion ◽  
Beta Thalassemia ◽  
Ribonuclease Protection Assay ◽  
Beta Globin ◽  
Gamma Delta ◽  
Beta Globin Gene ◽  
Thalassemia Minor

We have previously described an English family with gamma delta beta- thalassemia in which a large deletion stops 25 kilobases (kb) upstream from the beta-globin gene locus, and yet the beta-globin gene is inactive in vivo. Affected family members had a beta-thalassemia minor phenotype with a normal hemoglobin A2 level. Gene mapping showed that these subjects were heterozygous for a chromosome bearing a large deletion that began in the G gamma-globin gene, extended through the epsilon-globin gene, and continued upstream for at least 75 kb. The A gamma-, delta-, and beta-globin gene loci on this chromosome were intact. To examine the possibility that an additional defect was present in the beta-globin gene, we cloned, sequenced, and examined the expression of the beta-globin gene from the affected chromosome. No mutation was found in the beta-globin gene sequence from 990 base-pairs 5′ to the cap site to 350 basepairs 3′ to the polyadenylation signal. The gene was subcloned into an expression vector and introduced into HeLa cells. Analysis of RNA derived from these cells, using a ribonuclease protection assay, revealed qualitatively and quantitatively normal transcription. Thus a structurally and functionally normal beta-globin gene is inactive in the presence of a large deletion more than 25 kb upstream. The loss of beta-globin gene function may be due to disturbance of chromatin conformation caused by the deletion or may be the result of loss of upstream sequences that are necessary for beta-globin gene expression in vivo.

scholarly journals Asynchronous globin chain synthesis in rabbit reticulocyte lystates induced by hemin-controlled repressor

Blood ◽  
1978 ◽  
Vol 51 (4) ◽  
pp. 653-658 ◽  
Author(s):  
RS Franco ◽  
JW Hogg ◽  
OJ Martelo
Keyword(s):  
Globin Chain ◽  
Free System ◽  
Globin Chains ◽  
Reticulocyte Lysate ◽  
Chain Imbalance ◽  
Globin Synthesis ◽  
Chain Synthesis ◽  
Globin Chain Synthesis

Abstract To define further the role of hemin-controlled repressor (HCR) in globin synthesis, we studied its effect on the synthesis of individual globin chains in a rabbit reticulocyte lysate cell-free system. In the presence of HCR there was a marked globin chain imbalance, resulting in a lowered alpha/beta ratio. These findings in vitro may have relevance to certain clinical heme deficiency states in which a similar globin chain imbalance has been observed.

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