Divergent regulation of cell surface protease expression in HL-60 cells differentiated into macrophages with granulocyte macrophage colony stimulating factor or neutrophils with retinoic acid.
Taking advantage of the recently demonstrated presence of N-aminopeptidases and the serine protease dipeptidyl aminopeptidase IV (DPP IV) at the surface of human myeloblastic HL-60 cells, the regulation of these protease activities in HL-60 cell differentiation has been assessed using combined spectrophotometric and flow cytometric assays. Addition of human recombinant granulocyte macrophage colony stimulating factor (rHu-GM-CSF) to HL-60 cells to induce differentiation into macrophages led to a time- and dose-dependent increase in both cell surface N-aminopeptidase and DPP IV activities. Protease up-regulation was due to an enhancement in cell surface protease number, associated with a slight rise in apparent affinities of the enzymes for their substrates. In contrast, in HL-60 cells induced to differentiate into neutrophils in the presence of retinoic acid, expression of cell surface N-aminopeptidases was almost completely abolished in a time- and dose-dependent fashion, and this down-regulation was accompanied by a weak but significant decrease in affinity. However, no noticeable difference was seen in serine DPP IV expression between retinoic acid-treated and untreated HL-60 cells. Retinoic acid treatment also reduced soluble protease activity in vitro indicating that down-regulation of membrane aminopeptidases was not due to their proteolytic clip. No modulation in the activity of any of the enzymes tested was seen with human recombinant tumor necrosis factor-alpha or retinol which do not induce HL-60 cell differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)
Laouar
A
A
Unité 365 INSERM, Institut Curie, Paris, France.
Wietzerbin
J
J
Bauvois
B
B
D001773:Blood Cells / Q000201:enzymology; D002454:Cell Differentiation / Q000187:drug effects; D002462:Cell Membrane / Q000201:enzymology; D010450:Endopeptidases / Q000032:analysis*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute / Q000201:enzymology* / Q000473:pathology; D008264:Macrophages / Q000166:cytology / Q000201:enzymology*; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology*; D011994:Recombinant Proteins / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D011994:Recombinant Proteins; D014212:Tretinoin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D010450:Endopeptidases