Hiruma H, Noguchi C T, Uyesaka N, Hasegawa S, Blanchette-Mackie E J, Schechter A N, Rodgers G P
Laboratory of Chemical Biology, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland 20892.
Am J Hematol. 1995 Jan;48(1):19-28. doi: 10.1002/ajh.2830480105.
Sickle cell disease pathophysiology is mediated by acute and chronic impairment of cell flexibility due to the formation of intracellular sickle hemoglobin (Hb S) polymer as cells are partially deoxygenated in the microcirculation. We have recently developed a method to measure the relationship between the formation of intracellular polymerized Hb S and cell filtration. In this study, we have used this method to examine whether sickle cell morphology, independent of Hb S polymer fraction, had an effect on cell rheology. We primarily use sickle trait (AS) and Hb S-beta(+)-thalassemia (S-beta(+)-thal) erythrocytes with low hemoglobin F levels, which have normal membranes and few or no dense cells, to remove these confounding effects. We find that the relationship between filtration and the percentages of each "type" of morphological deformation of AS erythrocytes was different from that of the S-beta(+)-thal erythrocytes. In addition, we find that while the filtration of AS erythrocytes as a function of oxygen saturation was similar, whether measured during deoxygenation or reoxygenation, the relationship between the percentages of each type of deformed erythrocyte and oxygen saturation demonstrated hysteresis during oxygenation-deoxygenation experiments. Transmission electron microscopy, for both elongated and irregularly shaped cells, showed that similarly distorted cells could have very different amounts and alignment of polymer. These results suggests that cell morphology per se is not strongly related to filtration, whereas calculated intracellular Hb S polymer fraction predicts loss of filtration of AS and S-beta(+)-thal erythrocytes well. Measured or calculated polymer fraction values would appear to be a better parameter for the study of sickle cell disease pathophysiology and response to treatment than cell morphology studies.
镰状细胞病的病理生理学是由细胞灵活性的急性和慢性损伤介导的，这是由于在微循环中细胞部分脱氧时细胞内镰状血红蛋白（Hb S）聚合物的形成。我们最近开发了一种方法来测量细胞内聚合Hb S的形成与细胞过滤之间的关系。在本研究中，我们使用这种方法来检查镰状细胞形态（独立于Hb S聚合物分数）是否对细胞流变学有影响。我们主要使用血红蛋白F水平低的镰状性状（AS）和Hb S-β（+）-地中海贫血（S-β（+）-thal）红细胞，这些红细胞具有正常的膜且很少或没有致密细胞，以消除这些混杂效应。我们发现，AS红细胞每种“类型”形态变形的百分比与过滤之间的关系不同于S-β（+）-thal红细胞。此外，我们发现，虽然AS红细胞的过滤作为氧饱和度的函数是相似的，无论在脱氧还是复氧期间测量，但在氧合-脱氧实验期间，每种变形红细胞的百分比与氧饱和度之间的关系表现出滞后现象。对于细长形和不规则形细胞的透射电子显微镜检查表明，同样扭曲的细胞可能具有非常不同数量和排列的聚合物。这些结果表明，细胞形态本身与过滤没有强烈关系，而计算得出的细胞内Hb S聚合物分数能很好地预测AS和S-β（+）-thal红细胞过滤的丧失。与细胞形态学研究相比，测量或计算的聚合物分数值似乎是研究镰状细胞病病理生理学和治疗反应的更好参数。
