Defective assembly of membrane proteins in erythroid precursors of β-thalassemic mice

• Published in: Blood Vol. 84; no. 2; pp. 632 - 637
• Main Authors: YUAN, J, RUBIN, E, ALJURF, M, MA, L, SCHRIER, S. L
• Format: Journal Article
• Language: English
• Published: Washington, DC The Americain Society of Hematology 15.07.1994
• Subjects: Animals; beta-Thalassemia - blood; Biological and medical sciences; Cell Separation; Erythroid Precursor Cells - chemistry; Immunodeficiencies. Immunoglobulinopathies; Immunoglobulinopathies; Immunopathology; Medical sciences; Membrane Proteins - analysis; Mice; Mice, Inbred C57BL; Hemoglobinopathy; Membrane protein; Erythroid cell; Stem cell; Rodentia; Exploration; Hemopathy; Genetic disease; Vertebrata; Experimental disease; Hemolytic anemia; Mammalia; Mouse; β-Thalassemia; Animal
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V84.2.632.632

beta-Thalassemic mice provide a useful model for studying the pathophysiology of human beta-thalassemia in that one can perform experiments that are difficult to perform in humans. The ease of access to beta-thalassemic mouse marrow provided the opportunity to explore the cause of the ineffective erythropoiesis that characterizes severe beta-thalassemia in mouse and man. We hypothesized that the accumulation of excess alpha-globin might interfere with the normal assembly of red blood cell (RBC) membrane proteins, thus contributing to the severe intramedullary lysis. Femoral marrow was obtained from normal and beta-thalassemic mice, and RBC precursors were purified (> 90%) by panning and harvesting CD45- cells. The assembly of RBC membrane proteins was assessed by observing immunofluorescence patterns obtained on fixed permeabilized precursors using rabbit polyclonal antibodies directed against human spectrin, and band 4.1, and murine band 3. The distribution of the proteins was shown with a fluorescein-tagged goat antirabbit antibody. In contrast to normal mice, about 30% of intermediate and late stage erythroblasts in beta-thalassemic mice appear abnormal. Neither spectrin nor band 4.1 formed crisp rim fluorescence in these erythroid precursors of thalassemic mice, whereas assembly of band 3 appeared normal. Therefore, the assembly of membrane skeletal proteins is abnormal in murine beta-thalassemic erythroid precursors perhaps because of the deposition of unmatched alpha-globin chains.