Inducing effects of macrophage stimulating protein on the expansion of early hematopoietic progenitor cells in liquid culture.
BACKGROUND
Macrophage stimulating protein (MSP) is produced by human bone marrow endothelial cells. In this study, we sought to observe its effects on inducing the expansion of early hematopoietic progenitor cells which were cultured in a liquid culture system in the presence of the combination of stem cell factor (SCF), interleukin 3 (IL-3), interleukin 6 (IL-6), granulocyte macrophage-colony stimulating factor (GM-CSF), erythropoietin (EPO) (Cys) and MSP or of Cys and bone marrow endothelial cell conditioned medium (EC-CM).


METHODS
Human bone marrow CD34(+) cells were separated and cultured in a liquid culture system for 6 days. Granulocyte-macrophage colony forming unit (CFU-GM) and colony forming unit-granulocyte, erythrocyte, macrophage, megakaryocyte (CFU-GEMM) were employed to assay the effects of different treatment on the proliferation of hematopoeitic stem/progenitor cells. The nitroblue tetrazolium (NBT) reductive test and hoechest 33258 staining were employed to reflect the differentiation and apoptosis of the cells respectively.


RESULTS
MSP inhibited the proliferation of CFU-GM and CFU-GEMM in semi-solid culture and the inhibitory effect on CFU-GEMM was stronger than on CFU-GM. MSP inhibited the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators. Bone marrow (BM) CFU-GEMM was 2.3-fold or 1.7-fold increase or significantly decreased in either Cys + EC-CM, Cys + MSP or Cys compared with 0 hour control in liquid culture system after 6 days.


CONCLUSIONS
MSP, a hematopoietic inhibitor, inhibits the differentiation of early hematopoietic progenitor cells induced by hematopoietic stimulators and makes the early hematopoietic progenitor cells expand in a liquid culture system.
Ma
Li-xia
LX
Experimental Hematology Laboratory, Department of Physiology, Xiangya Medical School of Central South University, Changsha 410078, China.
Huang
Yan-hong
YH
Cheng
La-mei
LM
Lei
Jun
J
Wang
Qi-ru
QR
D018952:Antigens, CD34 / Q000032:analysis; D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D054405:Chemokine CCL3; D019742:Chemokines, CC / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D011518:Proto-Oncogene Proteins / Q000494:pharmacology*
D018952:Antigens, CD34; C515429:CCL3 protein, human; D054405:Chemokine CCL3; D019742:Chemokines, CC; D011518:Proto-Oncogene Proteins; C082332:macrophage stimulating protein; D017228:Hepatocyte Growth Factor