Yamaguchi H, Ishii E, Tashiro K, Miyazaki S
Division of Pediatrics, Saga Prefectural Hospital Koseikan, Saga Medical School, Japan.
Leuk Lymphoma. 1998 Sep;31(1-2):61-9. doi: 10.3109/10428199809057585.
Effective hematopoiesis is usually induced by interactions between hematopoietic progenitor cells (HPC) and stromal cells. In cord blood (CB), umbilical vein endothelial cells (HUVEC) can support HPC as a stromal microenvironment. EC activated mainly by IL-1 and TNFalpha produce a variety of cytokines and growth factors such as IL-1, IL-4, IL-6, GM-CSF and G-CSF. Since HPC express c-kit on their surface, the SCF produced by HUVEC plays an important role in the hematopoiesis of CB. We examined the expression of cytokines and growth factors on HUVEC by PCR. Resting HUVEC expressed high level of SCF, and low levels of IL-6, IL-7, and IL-8. Thus, a variety of cytokines and growth factors are produced by EC, and this cytokine network is thought to play an important role in regulating hematopoiesis. Activated EC can also express various adhesion molecules including E-selectin, VCAM-1 and ICAM-1, and facilitate the adhesion of hematopoietic cells to the endothelium. Furthermore, the interaction of CB cells with HUVEC has recently been shown in vitro. We previously showed that the culture media of HUVEC induced high numbers of colony formation. Suitable cytokine productions are thus provided to HPC by the interaction of HUVEC and cord MNC. On the basis of these findings, several mechanisms to support hematopoiesis in CB can be considered. Specific growth factors produced by EC bind to HPC to induce proliferation. While cell-cell interactions involve adhesion of HPC to HUVEC via adhesion molecules, and the adhesion of HPC to EC will facilitate interaction with cytokines and growth factors. Thus HPC in CB proliferate and are maintained by growth factors, and adhesion molecules produced by HUVEC, and HPC themselves.
有效的造血作用通常由造血祖细胞（HPC）与基质细胞之间的相互作用所诱导。在脐血（CB）中，脐静脉内皮细胞（HUVEC）可作为一种基质微环境来支持HPC。主要由白细胞介素-1（IL-1）和肿瘤坏死因子α（TNFα）激活的内皮细胞会产生多种细胞因子和生长因子，如IL-1、IL-4、IL-6、粒细胞-巨噬细胞集落刺激因子（GM-CSF）和粒细胞集落刺激因子（G-CSF）。由于HPC在其表面表达c-kit，HUVEC产生的干细胞因子（SCF）在脐血的造血过程中发挥着重要作用。我们通过聚合酶链反应（PCR）检测了HUVEC上细胞因子和生长因子的表达。静息的HUVEC表达高水平的SCF，以及低水平的IL-6、IL-7和IL-8。因此，内皮细胞会产生多种细胞因子和生长因子，并且这种细胞因子网络被认为在调节造血作用中发挥着重要作用。激活的内皮细胞还可表达包括E-选择素、血管细胞黏附分子-1（VCAM-1）和细胞间黏附分子-（ICAM-1）在内的多种黏附分子，并促进造血细胞与内皮的黏附。此外，最近在体外已证实脐血细胞与HUVEC之间存在相互作用。我们之前表明，HUVEC的培养基可诱导大量集落形成。因此，通过HUVEC与脐血单个核细胞（MNC）的相互作用，可向HPC提供合适的细胞因子产物。基于这些发现，可以考虑几种支持脐血造血的机制。内皮细胞产生的特定生长因子与HPC结合以诱导增殖。而细胞间相互作用涉及HPC通过黏附分子与HUVEC的黏附，并且HPC与内皮细胞的黏附将促进其与细胞因子和生长因子的相互作用。因此，脐血中的HPC通过生长因子、HUVEC产生的黏附分子以及HPC自身而增殖并得以维持。
