title: Calcium-dependent human erythrocyte cytoskeleton stability analysis through atomic force microscopy.
abstract: Erythrocytes affected by age and diseases such as sickle cell anemia, hypertension, diabetes, etc., exhibit abnormally high intracellular Ca2+ ion levels, and appear to have altered cytoskeleton properties. It has been proposed that extra binding of Ca2+ to membrane-associated calmodulin attenuates the spectrin-ankyrin-Band 3 tether of the cytoskeleton to the cytoplasmic membrane and might change the cytoskeleton structure. Due to the close apposition of the network, direct observation of such a structural change in vivo is restricted. In this study, atomic force microscopy and quantitative image analysis were applied to investigate the structural change of young healthy erythrocyte cytoskeletons upon extra Ca2+ binding to the cytoplasmic membrane in vitro. The results show that extra Ca2+ binding increased the cytoskeleton rigidity and prevented spectrin aggregation during sample preparation. The cytoskeleton morphology observed in Ca2+ -incubated healthy young cell were similar to the glutaraldehyde-fixed healthy young cells.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizukami
authors.forename: Sharada
authors.initials: S
authors.lastname: Sarnaik
authors.forename: Agnes
authors.initials: A
authors.lastname: Ostafin
mesh_terms: D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D017487:Ankyrins / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D048430:Cell Shape; D003599:Cytoskeleton / Q000187:drug effects* / Q000473:pathology; D004912:Erythrocytes / Q000473:pathology*; D006801:Humans; D018625:Microscopy, Atomic Force; D013049:Spectrin / Q000378:metabolism
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D017487:Ankyrins; D013049:Spectrin; D002118:Calcium