Seifert, Roland and Jungblut, P. and Schultz, Günter
Differential expression of cytosolic activation factors for NADPH oxidase in HL-60 leukemic cells.
Biochemical and biophysical research communications 161 (3), pp. 1109-1117.
Activation of NADPH oxidase in undifferentiated HL-60 leukemic cells and in HL-60 cells differentiated along the myeloid pathway with dibutyryl cyclic AMP (dbcAMP) or dimethyl sulfoxide (Me2SO) was studied. Upon stimulation with a calcium ionophore, a phorbol ester, arachidonic acid or gamma-hexachlorocyclohexane, Me2SO-differentiated HL-60 cells generated superoxide (O2-) at higher rates than dbcAMP-differentiated cells. Undifferentiated cells generated O2- only at low rates upon stimulation with the above agents. In cell-free systems, NADPH oxidase activity was reconstituted by combining membranes of undifferentiated or dbcAMP- or Me2SO-differentiated HL-60 cells, cytosol of Me2SO-differentiated cells and arachidonic acid. This basal O2- formation was enhanced several-fold by guanosine 5'-O-(3-thiotriphosphate) (GTP[gamma S]), a potent activator of guanine nucleotide-binding proteins. In contrast, cytosol of dbcAMP-differentiated cells reconstituted O2- formation only in the presence of GTP[gamma S], and cytosol of undifferentiated cells was inactive. Submaximally stimulatory amounts of cytosolic protein of Me2SO- and dbcAMP-differentiated cells synergistically stimulated O2- formation in the presence but not in the absence of GTP[gamma S]. We conclude that differentiations of HL-60 cells with Me2SO and dbcAMP are not equivalent with respect to activation of NADPH oxidase and that two cytosolic activation factors are involved in the regulation of this effector system.
|Institutions:|| Chemistry and Pharmacy > Institute of Pharmacy > Pharmacology and Toxicology (Prof. Schlossmann formerly Prof. Seifert)|
|Cell Differentiation/drug effects||MESH|
|Leukemia, Promyelocytic, Acute||MESH|
|NADH, NADPH Oxidoreductases/metabolism||MESH|
|Subjects:||600 Technology > 610 Medical sciences Medicine|
600 Technology > 615 Pharmacy
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||24 Jan 2012 13:31|
|Last Modified:||24 Jan 2012 13:32|