Coagulation and Splenectomy: An Overview

Cappellini, Maria Domenica; Grespi, E.; Cassinerio, Elena; Bignamini, Daniela; Fiorelli, G.

doi:10.1196/annals.1345.039

Cited by 101 publications

(78 citation statements)

References 36 publications

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“…In a study of 120 thalassemia patients with hemoglobin E-thalassemia of varying clinical severity from Thailand, no mutations were identified in the exons of the AHSP gene or in the 5Ј-flanking DNA (28). Similar results were found in a population of ␤-thalassemic patients from Italy (29). However, in separate preliminary reports (30,4), thalassemic patients with discordant phenotypes were found to have decreased AHSP mRNA expression in reticulocytes and cultured erythroid precursors as determined by realtime, reverse transcription polymerase chain reaction.…”

Section: Discussionsupporting

confidence: 67%

GATA-1 and Oct-1 Are Required for Expression of the Human α-Hemoglobin-stabilizing Protein Gene

Gallagher

Liem

Wong

et al. 2005

Journal of Biological Chemistry

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␣-Hemoglobin-stabilizing protein (AHSP) is an erythroid protein that binds and stabilizes ␣-hemoglobin during normal erythropoiesis and in pathological states of ␣-hemoglobin excess. AHSP has been proposed as a candidate gene in some Heinz body hemolytic anemias and as a modifier gene in the ␤-thalassemia syndromes. To gain additional insight into the molecular mechanisms controlling the erythroid-specific expression of the AHSP gene and provide the necessary tools for further genetic studies of these disorders, we have initiated identification and characterization of the regulatory elements controlling the human AHSP gene. We mapped the 5-end of the AHSP erythroid cDNA and cloned the 5-flanking genomic DNA containing the putative AHSP gene promoter. In vitro studies using transfection of promoter/reporter plasmids in human tissue culture cell lines, DNase I footprinting analyses and gel mobility shift assays, identified an AHSP gene erythroid promoter with functionally important binding sites for GATA-1-and Oct-1-related proteins. In transgenic mice, a reporter gene directed by a minimal human AHSP promoter was expressed in bone marrow, spleen, and reticulocytes, but not in nonerythroid tissues. In vivo studies using chromatin immunoprecipitation assays demonstrated hyperacetylation of the promoter region and occupancy by GATA-1. The AHSP promoter is an excellent candidate region for mutations associated with decreased AHSP gene expression.␣-Hemoglobin-stabilizing protein (AHSP, 2 also known as erythroid differentiation-related factor, EDRF, and erythroid-associated factor, ERAF) is a recently identified erythroid protein that binds free ␣-hemoglobin and stabilizes it in solution and in cells (1-3). Interaction with AHSP inhibits reactive oxygen species production from ␣-hemoglobin and prevents the precipitation of highly unstable, cytotoxic free ␣-globin chains, which aggregate in erythroid precursors, damaging the membrane and triggering cell death (5). Thus AHSP is critical during normal erythropoiesis, where ␣-globin chain synthesis normally exceeds ␤-globin chain synthesis, and to a greater extent during pathologic states of globin chain imbalance.Because of its role in stabilizing ␣-globin, it has been suggested that AHSP may be a modifier gene in the ␤-thalassemia syndromes (1, 6). Decreased or defective AHSP would be expected to worsen the phenotype of ␤-thalassemia because of the cytotoxic effects of excessive free ␣-hemoglobin. In a murine model, AHSP deficiency leads to well-compensated hemolysis with Heinz body formation, reticulocytosis, and increased apoptosis of erythroid precursors (5). When AHSP-deficient mice were bred to ␤-thalassemia mice, loss of AHSP increased the severity of the thalassemia (5). These studies also suggested that AHSP might play a role in unexplained Heinz body hemolytic anemia in humans.Identification and characterization of the regulatory elements that control AHSP gene expression have important implications for normal erythropoiesis and the pathogenesis of hemolytic dis...

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Section: Discussionsupporting

confidence: 67%

GATA-1 and Oct-1 Are Required for Expression of the Human α-Hemoglobin-stabilizing Protein Gene

Gallagher

Liem

Wong

et al. 2005

Journal of Biological Chemistry

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“…As splenectomy caused an increment in peripheral platelet counts [41,42], these findings suggest that the spleen may compromise the regenerative capacity of the liver and vice versa splenectomy may promote liver regeneration. However, the herein observed benefit in small-for-size livers can be clearly attributed to a rise in HABF with sufficient oxygen supply rather than to splenectomy itself because the beneficial effect of splenectomy was abolished by simultaneous ligation of the hepatic artery.…”

Section: Discussionmentioning

confidence: 90%

Splenectomy improves survival by increasing arterial blood supply in a rat model of reduced-size liver

Eipel¹,

Abshagen²,

Ritter³

et al. 2010

Transplant International

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“…Thrombin generation is significantly higher in splenectomized TI patients than in control subjects or patients who have not undergone splenectomy. 37 Moreover, a study showed significantly higher levels of circulating MP originated from RBC membranes in TI patients than in controls, with this difference being greater in splenectomized patients. 12 Circulating MP can be very noxious in different clinical settings such as acute coronary syndromes, atherosclerosis, post-transfusional acute respiratory distress syndrome, diabetes mellitus, systemic inflammatory disease and disseminated intravascular coagulation.…”

Section: Discussionmentioning

confidence: 99%

Thalassemic erythrocytes release microparticles loaded with hemichromes by redox activation of p72Syk kinase

Ferru

Pantaleo

Carta³

et al. 2013

Haematologica

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© F e r r a t a S t o r t i F o u n d a t i o ndifferent genetic and clinical status provided new insights into the pathogenic role of circulating MP and possible interventions to control their amount in thalassemia. MethodsUnless otherwise stated, all materials were obtained from Sigma-Aldrich, St. Louis, MO, USA. Additional information about the methods are provided in the Online Supplementary Data. Treatment of red blood cellsVenous blood was drawn from 12 healthy individuals, eight non-splenectomized TI patients and six splenectomized TI patients. All subjects provided written, informed consent before entering the study. The study was approved by the local Ethics Committee and conducted in accordance with Good Clinical Practice guidelines and the Declaration of Helsinki.Clinical analyses were performed by routine laboratory tests at the Policlinico Hospital (Milan, Italy). Blood anti-coagulated with heparin was stored in citrate-phosphate-dextrose with adenine (CPDA-1) prior to its use. RBC were washed three times with phosphate-buffered saline (PBS: 137mM NaCl, 2.7mM KCl, 8.1mM K 2 HPO 4 , 1.5mM KH 2 PO 4 , pH 7.4) containing glucose 5 mM to obtain packed RBC.To stimulate HMC formation, RBC from healthy donors were suspended at a hematocrit of 30% and incubated with different concentrations (0, 0.25, 0.5, 1, 1.5, 2 mM) of phenylhydrazine at 37 °C for 4 h. To test the antioxidant effect in MP release we incubated 200 μM of 2-mercaptoethanol in the presence of 1 mM phenylhydrazine. When necessary, RBC were pretreated with Syk kinase inhibitors (10 μM Syk inhibitors II and 10 μM Syk inhibitors IV, Calbiochem, Darmstadt, Germany), for 1 h at 37 °C in the dark. Each reaction was terminated by three washes with PBS-glucose. For all protocols described, untreated controls were processed identically except that the stimulant/inducer was omitted from the incubation. Red blood cell membrane preparationStandard hypotonic membranes were prepared, as previously described, 20 and stored frozen at -80°C until use. Membrane protein content was quantified using the DC Protein assay (Biorad, Hercules, CA, USA). Analysis of microparticlesThe MP in plasma were analyzed by flow cytometry using a modification of a previously described method:22 25 μL of plasma diluted 1:1 with PBS-glucose 5mM were analyzed using anti-CD41 (BD, Franklin Lakes, NJ, USA) and anti-glycophorin-A (Dako, Denmark), both diluted 1:10. Assay of hemichromesHMC were quantified by measuring heme absorbance (Abs) using the following equation:HMC= -133xAbs577 -114xAbs630 + 233xAbs560, and expressed as nMoles/mL of solubilized membranes. 23 Microparticle isolationTo induce MP release in vitro, RBC from each volunteer and phenylhydrazine-treated RBC in PBS (30% hematocrit) were incubated as previously described. 24 Electrophoresis and immunoblottingMembrane and MP proteins were solubilized in Laemmli buffer 25 under reducing [2% (w/v) dithiothreitol] or non-reducing conditions at a volume ratio of 1:1. Sodium dodecylsulfate polyacrylamide gel electropho...

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Coagulation and Splenectomy: An Overview

Cited by 101 publications

References 36 publications

GATA-1 and Oct-1 Are Required for Expression of the Human α-Hemoglobin-stabilizing Protein Gene

GATA-1 and Oct-1 Are Required for Expression of the Human α-Hemoglobin-stabilizing Protein Gene

Splenectomy improves survival by increasing arterial blood supply in a rat model of reduced-size liver

Thalassemic erythrocytes release microparticles loaded with hemichromes by redox activation of p72Syk kinase

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