Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, USA.
Exp Hematol. 2013 Apr;41(4):398-408.e2. doi: 10.1016/j.exphem.2012.11.007. Epub 2012 Nov 30.
During murine embryogenesis, primitive erythroblasts enter the circulation as immature nucleated cells and progressively mature as a semisynchronous 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 regardless of whether 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.
在鼠类胚胎发生过程中，原始红细胞作为未成熟的有核细胞进入循环系统，并在 E12.5 至 E16.5 之间进行半同步的去核过程中逐渐成熟。在本报告中，我们研究了这些细胞的力学特性，以确定它们的机械发育与血管外成熟于受保护骨髓微环境中的定型红细胞有何不同。原始红细胞在 E12.5 时获得正常的细胞膜变形性（即晚期红细胞），并通过 E17.5 保持相同的表面硬度水平。在此期间，膜双层与底层骨架之间的结合强度增加，这表明分离双层和骨架所需的能量大约增加了一倍。与此同时，这些细胞的表面积和体积发生了剧烈变化，从 E14.5 到 E17.5 时表面积减少了 35%，体积减少了 50%。有趣的是，无论细胞是否完成去核，膜重塑过程都会进行。这些数据表明，与定型红细胞不同，原始红细胞的膜重塑和去核这两个关键成熟过程是解耦的。
