Different Involvement of Band 3 in Red Cell Deformability and Osmotic Fragility-A Comparative GP.Mur Erythrocyte Study

Cells. 2021 Nov 30;10(12):3369. doi: 10.3390/cells10123369.

Abstract

GP.Mur is a clinically important red blood cell (RBC) phenotype in Southeast Asia. The molecular entity of GP.Mur is glycophorin B-A-B hybrid protein that promotes band 3 expression and band 3-AQP1 interaction, and alters the organization of band 3 complexes with Rh/RhAG complexes. GP.Mur+ RBCs are more resistant to osmotic stress. To explore whether GP.Mur+ RBCs could be structurally more resilient, we compared deformability and osmotic fragility of fresh RBCs from 145 adults without major illness (47% GP.Mur). We also evaluated potential impacts of cellular and lipid factors on RBC deformability and osmotic resistivity. Contrary to our anticipation, these two physical properties were independent from each other based on multivariate regression analyses. GP.Mur+ RBCs were less deformable than non-GP.Mur RBCs. We also unexpectedly found 25% microcytosis in GP.Mur+ female subjects (10/40). Both microcytosis and membrane cholesterol reduced deformability, but the latter was only observed in non-GP.Mur and not GP.Mur+ normocytes. The osmotic fragility of erythrocytes was not affected by microcytosis; instead, larger mean corpuscular volume (MCV) increased the chances of hypotonic burst. From comparison with GP.Mur+ RBCs, higher band 3 expression strengthened the structure of RBC membrane and submembranous cytoskeletal networks and thereby reduced cell deformability; stronger band 3-AQP1 interaction additionally supported osmotic resistance. Thus, red cell deformability and osmotic resistivity involve distinct structural-functional roles of band 3.

Keywords: AQP1 (aquaporin-1); GP.Mur (Miltenberger subtype III); band 3; deformability; erythrocyte (red blood cells); mean corpuscular volume (MCV); membrane cholesterol; microcytosis; osmotic fragility.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anion Exchange Protein 1, Erythrocyte / metabolism*
  • Aquaporin 1 / metabolism
  • Cholesterol / blood
  • Cholesterol / metabolism
  • Erythrocyte Count
  • Erythrocyte Deformability*
  • Erythrocyte Membrane / metabolism
  • Erythrocytes / metabolism*
  • Erythrocytes / pathology*
  • Humans
  • Models, Biological
  • Multivariate Analysis
  • Osmotic Fragility*
  • Protein Binding
  • Regression Analysis

Substances

  • Anion Exchange Protein 1, Erythrocyte
  • Aquaporin 1
  • Cholesterol