Sporn L A, Chavin S I, Marder V J, Wagner D D
J Clin Invest. 1985 Sep;76(3):1102-6. doi: 10.1172/JCI112064.
Immunofluorescence staining of buffy coat smears from a patient with chronic myelogenous leukemia in accelerated phase showed that approximately 13% of all nucleated cells contained von Willebrand protein and, therefore, appeared to be of megakaryocytic origin. This was confirmed by positive staining with antisera against platelet factor 4 and platelet glycoproteins. Short-term cultures of the buffy coat, which lacked endothelial cells, were metabolically labeled with [35S]methionine, and von Willebrand protein was immunopurified from cell lysates and culture medium. Cultures from this patient synthesized and secreted von Willebrand protein, in contrast with cultures from other patients with leukemia, who lacked circulating megakaryocytes, and from normal volunteers. The subunit composition of the megakaryocytic von Willebrand protein was very similar to that of human umbilical vein endothelial cells. The size of the processed subunit (220 kD) and of the cellular (260 kD) and secreted (275 kD) precursors from the two cell types were indistinguishable by gel electrophoresis. Furthermore, the ratio of precursor to processed subunit and the pattern of cellular and secreted nonreduced multimers were very similar. It appears, therefore, that the processing steps in biosynthesis of von Willebrand protein used by the megakaryocytes are very similar to those of umbilical vein endothelial cells.
对一名处于加速期的慢性粒细胞白血病患者的血沉棕黄层涂片进行免疫荧光染色显示，所有有核细胞中约13%含有血管性血友病因子蛋白，因此似乎源自巨核细胞。用抗血小板因子4和血小板糖蛋白的抗血清进行阳性染色证实了这一点。对缺乏内皮细胞的血沉棕黄层进行短期培养，用[35S]甲硫氨酸进行代谢标记，然后从细胞裂解物和培养基中免疫纯化血管性血友病因子蛋白。与其他缺乏循环巨核细胞的白血病患者以及正常志愿者的培养物相比，该患者的培养物合成并分泌了血管性血友病因子蛋白。巨核细胞来源的血管性血友病因子蛋白的亚基组成与人类脐静脉内皮细胞的亚基组成非常相似。通过凝胶电泳无法区分两种细胞类型中加工后的亚基（220 kD）以及细胞内（260 kD）和分泌型（275 kD）前体的大小。此外，前体与加工后亚基的比例以及细胞内和分泌型非还原多聚体的模式非常相似。因此，看来巨核细胞用于血管性血友病因子蛋白生物合成的加工步骤与脐静脉内皮细胞的加工步骤非常相似。
