Decrease in nucleoside diphosphate kinase (NDPK/nm23) expression during hematopoietic maturation.
The nucleoside diphosphate kinase (NDPK/nm23) isoforms H1 and H2 were localized in hematopoietic tissues. Flow cytometric analysis and enzymatic assays were used to quantify the intracellular and extracellular concentrations of NDPK. Bone marrow CD34(+) progenitors contained the highest intracellular levels of both nm23-H1 and nm23-H2. Lower levels were measured in more mature bone marrow cells, whereas peripheral blood leukocytes had the lowest expression of nm23. These data suggest a function of NDPK in early hematopoiesis and a down-regulation of NDPK upon differentiation. In addition, an up-regulation of nm23 expression was observed in lymphocytes after induction of proliferation with phytohemagglutinin. Multiparameter flow cytometry demonstrated that this up-regulation occurred during the G0/G1-transition. Flow cytometric analysis also revealed a weak surface expression of nm23 on a number of hematopoietic cell lines, which was not detected on normal hematopoietic cells. Our data also demonstrated the presence of NDPK in human plasma, probably due to a limited in vivo lysis of red blood cells.
Willems
R
R
Laboratory of Experimental Hematology, Department of Medicine, University of Antwerp, Antwerp University Hospital (UIA/UZA), Wilrijkstraat 10, B-2650 Edegem, Belgium.
Van Bockstaele
D R
DR
Lardon
F
F
Lenjou
M
M
Nijs
G
G
Snoeck
H W
HW
Berneman
Z N
ZN
Slegers
H
H
D002454:Cell Differentiation; D002462:Cell Membrane / Q000201:enzymology; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000201:enzymology*; D006801:Humans; D020559:Monomeric GTP-Binding Proteins; D054778:NM23 Nucleoside Diphosphate Kinases; D009701:Nucleoside-Diphosphate Kinase / Q000097:blood*; D014157:Transcription Factors / Q000097:blood*
D054778:NM23 Nucleoside Diphosphate Kinases; D014157:Transcription Factors; C517938:NME1 protein, human; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins