Liu Mei-Li, Cai Ji-Ye, Yang Long-Jiang, Meng Fan-Yi, Wang Xiao-Yan, Liang Zhi-Hong, Li Ling-Song
Department of Chemistry, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2004 Dec;12(6):793-7.
Human CD34(+) hematopoietic cells, a distinctive cell population containing hematopoietic stem/progenitor cells (HSPC), have the capability to highly self-renewal, differentiation into all lineages of committed progenitor cells and reconstitution of both long-term hematopoiesis and immunefunctions after transplantation. CD34(+) hematopoietic cells from bone marrow (BM) recently have been employed for treating neoplastic and genetic disorders. This study was aimed to investigate membrane surface ultrastructures of bone marrow CD34(+) cell from mormal persons and leukemia patients and to compare their morphologic differences by using atomic force microscope (AFM). BM was collected from 5 normal donors and 6 leukaemia patients. All samples were layered on Ficoll-Paque gradients (specific gravity 1.077 g/ml) to separate the mononuclear cells. After that CD34(+) cells were purified by immuno-magnetic bead separation and evaluated with a FACS Calibur, these cells were detected by AFM of tapping mode inair. At lest 20 cells per samples were observed. The results showed that most of CD34(+) hematopoietic cells were like circle plate, the diameter was 10 - 14 microm. The surface of CD34(+) hematopoietic cell membrane was comparatively complex. The surface of CD34(+) hematopoietic cell membrane appeared as granular, with packed particles. With the region analysis function of IP2.1 software, the region of 2 microm x 2 microm was selected and four parameters of the surface (maximum peak-to-valley distance, average roughness, root-mean-squared roughness and mean height) were measured. Values of the 4 parameters showed that the characteristic parameters of CD34(+) HSPC from leukaemia were higher than that from normal person. It is concluded that AFM has specific advantages in analyzing cell membrane in the nanometer level and can gain more information. With the help of analysis software, AFM can be a helpful tool for fast leukaemic diagnosis and CD34(+) hematopoietic cells selection.
人CD34(+)造血细胞是一种包含造血干细胞/祖细胞（HSPC）的独特细胞群体，具有高度自我更新能力，能够分化为所有谱系的定向祖细胞，并在移植后重建长期造血和免疫功能。来自骨髓（BM）的CD34(+)造血细胞最近已被用于治疗肿瘤和遗传性疾病。本研究旨在利用原子力显微镜（AFM）研究正常人和白血病患者骨髓CD34(+)细胞的膜表面超微结构，并比较它们的形态学差异。从5名正常供体和6名白血病患者采集骨髓。所有样本分层于Ficoll-Paque梯度（比重1.077 g/ml）上以分离单核细胞。之后通过免疫磁珠分离纯化CD34(+)细胞并用FACS Calibur进行评估，这些细胞在空气中采用轻敲模式的AFM进行检测。每个样本至少观察20个细胞。结果显示，大多数CD34(+)造血细胞呈圆盘状，直径为10 - 14微米。CD34(+)造血细胞膜表面相对复杂。CD34(+)造血细胞膜表面呈颗粒状，有密集的颗粒。利用IP2.1软件的区域分析功能，选择2微米×2微米的区域并测量表面的四个参数（最大峰谷距离、平均粗糙度、均方根粗糙度和平均高度）。这4个参数的值表明，白血病患者的CD34(+) HSPC的特征参数高于正常人。结论是，AFM在纳米水平分析细胞膜方面具有独特优势，能够获取更多信息。借助分析软件，AFM可成为快速白血病诊断和CD34(+)造血细胞选择的有用工具。
