Development of membrane mechanical function during terminal stages of primitive erythropoiesis in mice.

Department of Biomedical Engineering, University of Rochester Medical Center, 601 Elmwood Ave., Rochester, NY 14642.
Experimental hematology (Impact Factor: 3.11). 11/2012; DOI: 10.1016/j.exphem.2012.11.007
Source: PubMed

ABSTRACT During murine embryogenesis, primitive erythroblasts enter the circulation as immature nucleated cells and progressively mature as a semi-synchronous cohort, enucleating between E12.5 and E16.5. In this report, we examine the mechanical properties of these cells to determine how their mechanical development differs from that of definitive erythroid cells, which mature extravascularly in protected marrow microenvironments. Primitive erythroid cells acquire normal membrane deformability by E12.5, i.e., as late stage erythroblasts, and maintain the same level of surface stiffness through E17.5. During this same period, the strength of association between the membrane bilayer and the underlying skeleton increases, as indicated by an approximate doubling of the energy required to separate bilayer from skeleton. At the same time, these cells undergo dramatic changes in surface area and volume, losing 35% of their surface area and 50% of their volume from E14.5 to E17.5. Interestingly, membrane remodeling proceeded whether or not the cells completed enucleation. These data suggest that in primitive erythroid cells, unlike their definitive counterparts, the critical maturational processes of membrane remodeling and enucleation are uncoupled.

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